FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Stark, MT Bishop, RL Miksa, E AF Stark, MT Bishop, RL Miksa, E TI Ceramic technology and social boundaries: Cultural practices in Kalinga clay selection and use SO JOURNAL OF ARCHAEOLOGICAL METHOD AND THEORY LA English DT Review DE ceramic composition; quantitative petrography; ethnoarchaeology; social boundaries ID ARCHAEOLOGICAL CERAMICS; COMPOSITIONAL CHARACTERIZATION; POTTERY PRODUCTION; ACID-EXTRACTION; DETRITAL MODES; STYLE; PHILIPPINES AB This study examines cultural sources of variation in ceramic compositional patterning in two pottery-making villages of the highland Philippines. In Dalupa, many potters are part-time specialists whereas in Dangtalan, women make pottery less frequently. Previous studies show that both pottery form and decoration correspond well with Kalinga social boundaries, but how do morphological and decorative patterning relate to compositional variability? Although researchers have made substantial advances in our understanding of natural and postdepositional sources of compositional variability, little is known about behavioral factors that affect chemical and mineralogical compositional patterning. This study examines cultural practices of clay selection and use in an ethnographic setting, and undertakes technical analyses to assess the relationship between behavior and material culture patterning. Our study identified paste differences between the clays and fired ceramics from Dangtalan and those from Dalupa. Findings from our compositional research thus parallel earlier morphological and stylistic studies, and illustrate multivariate differences in ceramics from these two Kalinga communities. This ethnoarchaeological and analytical project contributes, therefore, to understanding objective parameters within a behavioral context. It also provides an example of how a combined characterization approach, using chemical and petrographic techniques, can yield insights on intraregional variation at a finer scale of resolution than is often attempted. C1 Univ Hawaii, Dept Anthropol, Honolulu, HI 96822 USA. Smithsonian Inst, Washington, DC 20560 USA. RP Stark, MT (reprint author), Univ Hawaii, Dept Anthropol, Honolulu, HI 96822 USA. EM miriams@hawaii.edu NR 111 TC 45 Z9 45 U1 1 U2 15 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1072-5369 J9 J ARCHAEOL METHOD TH JI J. Archaeol. Method Theory PD DEC PY 2000 VL 7 IS 4 BP 295 EP 331 DI 10.1023/A:1026518922642 PG 37 WC Anthropology; Archaeology SC Anthropology; Archaeology GA 391PB UT WOS:000166363400002 ER PT J AU Stanley, DJ Hait, AK AF Stanley, DJ Hait, AK TI Holocene depositional patterns, neotectonics and sundarban mangroves in the western Ganges-Brahmaputra delta SO JOURNAL OF COASTAL RESEARCH LA English DT Article DE Bengal basin; borings; estuaries; Ganges-Brahmaputra delta; Holocene facies; mangroves; neotectonics; Pleistocene facies; population pressure; radiocarbon dating; salinity; sea level; sedimentation rate; subsidence rate; Sundarbans ID SEA-LEVEL RISE; RIVER SEDIMENT; NILE DELTA; BENGAL; EVOLUTION; STRATIGRAPHY; SUBSIDENCE; LANDFORMS; SEQUENCE; PLAIN AB Litho- and chronostratigraphic analyses of radiocarbon-dated cores are utilized herein to distinguish Holocene deltaic and underlying transgressive units and late Pleistocene alluvial deposits in the western Ganges-Brahmaputra delta. Regional distribution of these facies indicates that neotectonic displacement, including differential land subsidence, of delta plain sectors is one of the major controls of late Quaternary depositional patterns in this depocenter. The spatial and temporal configuration of Holocene deltaic sediment thickness, mud and sand layers, peats interstratified in Holocene sequences, and modern mangrove forests that form the Sundarbans are attributed to NE-SW, and to a lesser extent NW-SE, neotectonic trends. Holocene sedimentary and stratigraphic configurations closely parallel geological structures, some of them deep seated, that affected this region during most of the Tertiary and have continued to the present. Extensive mangrove forests developed along the NE-SW zone of thickened Holocene deltaic deposits. Their present configuration is related to natural factors, such as eastward tilting of the delta, rapid sediment accumulation (to 0.7 cm/yr), marked land subsidence (to 0.5 cm/yr), and increasing anthropogenic influences, including large-scale land reclamation and decreased river flow influx. The diverse and extensive mangrove tracts of the delta have significant environmental and economic implications for the rapidly growing population, including serving as a buffer zone that helps to reduce the impact of landward-driven tides, storms and cyclones. Interpretation of Holocene facies in the subsurface by means of radiocarbon-dated cores provides a mean to more precisely define the. interaction between contemporary Holocene depositional patterns and neotectonics. This information, in turn, can be utilized to develop realistic measures needed to minimize further degradation of this biologically unique ecosystem. C1 Smithsonian Inst, NMNH, Deltas Global Change Program, Washington, DC 20560 USA. Ctr Study Man & Environm, Calcutta 700091, W Bengal, India. RP Stanley, DJ (reprint author), Smithsonian Inst, NMNH, Deltas Global Change Program, Washington, DC 20560 USA. NR 70 TC 28 Z9 30 U1 3 U2 8 PU COASTAL EDUCATION & RESEARCH FOUNDATION PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 USA SN 0749-0208 J9 J COASTAL RES JI J. Coast. Res. PD WIN PY 2000 VL 16 IS 1 BP 26 EP 39 PG 14 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA 291QN UT WOS:000085747700004 ER PT J AU Marsh, AS Arnone, JA Bormann, BT Gordon, JC AF Marsh, AS Arnone, JA Bormann, BT Gordon, JC TI The role of Equisetum in nutrient cycling in an Alaskan shrub wetland SO JOURNAL OF ECOLOGY LA English DT Article DE biogeochemistry; decomposition; horsetail; phosphorus; potassium; root distribution ID CLUSTER ROOTS; NITROGEN; PRODUCTIVITY; PHYTOMASS AB 1 Although plants of Equisetum spp. are generally thought to be of little value to ecosystems, a study of a cold-temperate Alaskan shrub wetland showed that they acquired and cycled phosphorus and other nutrients more efficiently than other plant community members. While Equisetum plants represented only 5% of the above- and below-ground biomass in the community, they contained 16% of the P and 24% of the K. 2 Equisetum plants accounted for 29% of the P and 39% of the K in annual community foliage litterfall. Over a 2-year period, losses from Equisetum litter contributed 55, 41, and 75% of the P, K and Ca litter inputs into soil nutrient pools. 3 The ability of different species of Equisetum to acquire nutrients is linked to their deep rooting habit. While the majority of their roots and rhizomes, and particularly the fine roots, were located in the C horizon, the majority of roots and rhizomes of other species were located in the overlying O horizon. The biomass of Equisetum plants was also correlated with edaphic characteristics of the C horizon. 4 The absorption of nutrients from the C horizon by Equisetum helped bring P and other minerals to the soil surface, increasing the amount of minerals in the O horizon and thus making them potentially available to other species, including Myrica gale, Salix spp., and Carer spp. Productivity in this community is limited by P and N, and the ability of Equisetum to act as a nutrient pump may help explain why its net primary productivity is high for a cold-temperate wetland. C1 Yale Univ, Sch Forestry & Environm Studies, New Haven, CT 06511 USA. US Forest Serv, USDA, Pacific NW Res Stn, Corvallis, OR 97331 USA. RP Marsh, AS (reprint author), Smithsonian Environm Res Ctr, POB 28, Edgewater, MD 21037 USA. NR 56 TC 18 Z9 18 U1 0 U2 14 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0022-0477 J9 J ECOL JI J. Ecol. PD DEC PY 2000 VL 88 IS 6 BP 999 EP 1011 DI 10.1046/j.1365-2745.2000.00520.x PG 13 WC Plant Sciences; Ecology SC Plant Sciences; Environmental Sciences & Ecology GA 399DJ UT WOS:000166795700006 ER PT J AU Garcia-Heras, M AF Garcia-Heras, M TI Regional shared style and technology: A mineralogical and compositional study of Celtiberian pottery from Numantia, Spain SO JOURNAL OF FIELD ARCHAEOLOGY LA English DT Article AB Mineralogical and compositional characterizations research on Late Iron Age Celtiberian pottery from the Upper Duero Valley in central Spain are reported and their cultural implications discussed. Analyses shed new light on production and distribution patterns of Celtiberian pottery from excavations at the ancient town of Numantia, one of the best-known sites in the region. The results indicate that Numantian pottery was made using four different technological sequences of manufacture likely resulting from highly specialized and standardized mode of production. Mineralogical and compositional data suggest that pottery was locally produced, thereby providing evidence of a shared style and technology rather than a pattern of trade or exchange. C1 Smithsonian Ctr Materials Res & Educ, Suitland, MD USA. RP Garcia-Heras, M (reprint author), Smithsonian Ctr Materials Res & Educ, Suitland, MD USA. RI Garcia-Heras, Manuel/G-8803-2015 NR 44 TC 2 Z9 2 U1 0 U2 0 PU MANEY PUBLISHING PI LEEDS PA STE 1C, JOSEPHS WELL, HANOVER WALK, LEEDS LS3 1AB, W YORKS, ENGLAND SN 0093-4690 J9 J FIELD ARCHAEOL JI J. Field Archaeol. PD WIN PY 2000 VL 27 IS 4 BP 437 EP 454 DI 10.2307/3092721 PG 18 WC Archaeology SC Archaeology GA 584NX UT WOS:000177474700004 ER PT J AU Loftus, WF Reid, JW AF Loftus, WF Reid, JW TI Copepod (crustacea) emergence from soils from everglades marshes with different hydroperiods SO JOURNAL OF FRESHWATER ECOLOGY LA English DT Article ID WATERS AB During a severe drought period in the winter and spring of 1989, we made three collections of dried marsh soils from freshwater sloughs in Everglades National Park, Florida, at sites characterized by either long or intermediate annual periods of flooding (hydroperiod). After rehydrating the soils in aquaria, we documented the temporal patterns of copepod emergence over two-week periods. The species richness of copepods in the rehydrated soils was lower than in predrought samples from the same slough sites. Only six of the 16 species recorded from the Everglades emerged in the aquarium tests. The long hydroperiod site had a slightly different assemblage and higher numbers of most species than the intermediate-hydroperiod sites. More individuals and species emerged from the early dry-season samples compared with samples taken later in the dry season. The harpacticoid, Cletocamptus deirersi, and the cyclopoid, Microcyclops rubellus, were abundant at most sites. The cyclopoids - Ectocyclops phaleratus, Homocyclops ater, and Paracyclops chiltoni - are new records for the Everglades. We infer that 1) only a subset of Everglades copepod species can survive drought by resting in soils; and that 2) survival ability over time differs by species. C1 US Geol Survey, Everglades Natl Pk Field Stn, Biol Resources Div, Homestead, FL 33034 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, MRC 163, Washington, DC 20560 USA. RP Loftus, WF (reprint author), US Geol Survey, Everglades Natl Pk Field Stn, Biol Resources Div, 40001 State Rd 9336, Homestead, FL 33034 USA. NR 31 TC 10 Z9 10 U1 0 U2 3 PU OIKOS PUBL INC PI LA CROSSE PA PO BOX 2558, LA CROSSE, WI 54601 USA SN 0270-5060 J9 J FRESHWATER ECOL JI J. Freshw. Ecol. PD DEC PY 2000 VL 15 IS 4 BP 515 EP 523 DI 10.1080/02705060.2000.9663774 PG 9 WC Ecology; Limnology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 375YW UT WOS:000165431900011 ER PT J AU Li, X Habbal, SR AF Li, X Habbal, SR TI Electron kinetic firehose instability SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SOLAR-WIND; DISTRIBUTIONS; PLASMA AB The linear dispersion equation describing electromagnetic waves propagating in a homogeneous electron-proton plasma along arbitrary directions relative to the direction of the background magnetic field is solved numerically for bi-Maxwellian particle distributions. It is found that in the presence of an electron temperature anisotropy T-perpendicular to < T- and a sufficiently warm plasma (beta (e) > 2), several purely growing modes (zero real frequency) and a quasi-parallel electron firehose instability develop. While the quasi-parallel mode is unstable for both parallel and oblique propagation, the zero frequency modes are unstable only for oblique propagation. Comparison of these modes further shows that the propagation angle for maximum growth rate and the maximum growth rate are larger for the purely growing modes than the quasi-parallel electron firehose while the threshold is lower. Potential application of the kinetic electron firehose instability to the slow solar wind is briefly discussed. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Li, X (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 16 TC 31 Z9 31 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 1 PY 2000 VL 105 IS A12 BP 27377 EP 27385 DI 10.1029/2000JA000063 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 386BL UT WOS:000166040200024 ER PT J AU Liu, ZJ Weller, DE Correll, DL Jordan, TE AF Liu, ZJ Weller, DE Correll, DL Jordan, TE TI Effects of land cover and geology on stream chemistry in watersheds of Chesapeake Bay SO JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION LA English DT Article DE stream chemistry; land cover; geology; watershed studies; Chesapeake Bay ID RHODE RIVER WATERSHEDS; NITRATE CONTAMINATION; STORM EVENTS; PHOSPHORUS; DISCHARGES; NUTRIENTS; QUALITY; PRECIPITATION; COMPONENTS; TRANSPORT AB We measured the base-flow stream chemistry in all the major physiographic provinces of the Chesapeake Bay drainage basin. The spatial variation of stream chemistry was closely related to differences in geology and land cover among the sampled water-sheds. Some stream chemistry variables were strongly affected by geological settings in the watersheds while others were more influenced by land cover. The effects of land cover differed among chemical constituents and regions. Concentrations of Ca2+, Mg2+, pH, total alkalinity, and conductivity were mainly functions of carbonate bedrock, especially in the Great Valley. Nitrate-N and total dissolved N were closely related to cropland and increased as the percentage of cropland increased. The rate of increase varied from region to region with the highest in the Piedmont. Na+ and Cl-were mainly affected by the percentage of developed area in a watershed, especially in the Coastal Plain and Piedmont. We observed no significant effects of region or land cover on species of phosphorus because samples were collected under base now conditions and only dissolved forms were measured. Dissolved silicate (DSi) was not related to any other water chemistry variables. DSi increased as developed area decreased and cropland increased in the Coastal Plain, but these patterns were reversed in the Piedmont. There was no consistent pattern in the spatial variation of land cover effects on the reduced forms of N, dissolved organic P, dissolved organic matter, and K+. C1 Temple Univ, Dept Geog & Urban Studies, Philadelphia, PA 19122 USA. Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. RP Liu, ZJ (reprint author), Temple Univ, Dept Geog & Urban Studies, Philadelphia, PA 19122 USA. OI Weller, Donald/0000-0002-7629-5437 NR 45 TC 44 Z9 48 U1 2 U2 18 PU AMER WATER RESOURCES ASSOC PI MIDDLEBURG PA 4 WEST FEDERAL ST, PO BOX 1626, MIDDLEBURG, VA 20118-1626 USA SN 1093-474X J9 J AM WATER RESOUR AS JI J. Am. Water Resour. Assoc. PD DEC PY 2000 VL 36 IS 6 BP 1349 EP 1365 DI 10.1111/j.1752-1688.2000.tb05731.x PG 17 WC Engineering, Environmental; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA 391LP UT WOS:000166357700011 ER PT J AU Deem, SL Spelman, LH Yates, RA Montali, RJ AF Deem, SL Spelman, LH Yates, RA Montali, RJ TI Canine distemper in terrestrial carnivores: A review SO JOURNAL OF ZOO AND WILDLIFE MEDICINE LA English DT Review DE canine distemper virus; morbillivirus; nondomestic species; review; vaccine-induced disease ID DOGS LYCAON-PICTUS; BLACK-FOOTED FERRETS; VIRUS-INFECTION; SEROLOGIC SURVEY; DOMESTIC DOGS; MUSTELA-NIGRIPES; VIRAL PATHOGENS; NATIONAL-PARK; CDV INFECTION; MASAI-MARA AB Canine distemper virus is a member of the genus Morbillivirus in the family Paramyxoviridae. Canine distemper has been recorded in domestic dogs for centuries. It is now recognized as a worldwide problem of carnivores and has the second highest fatality rate of any infectious disease, after rabies, in domestic dogs. The importance of this disease in nondomestic animals has become evident with vaccine-induced infections in a variety of species and large-scale epidemics in captive and free-ranging felids. To date, canine distemper has been reported in all families of terrestrial carnivores: Canidae, Felidae, Hyaenidae, Mustelidae, Procyonidae, Ursidae, and Viverridae. Veterinarians, including those working with nondomestic carnivores, should be familiar with the clinical signs, diagnosis, and clinical management of this disease. C1 Wildlife Conservat Soc, Field Vet Program, Bronx, NY 10460 USA. Smithsonian Natl Zool Pk, Dept Anim Hlth, Washington, DC 20008 USA. RP Deem, SL (reprint author), Wildlife Conservat Soc, Field Vet Program, 185th St & So Blvd, Bronx, NY 10460 USA. NR 136 TC 123 Z9 137 U1 11 U2 69 PU AMER ASSOC ZOO VETERINARIANS PI MEDIA PA 6 NORTH PENNELL ROAD, MEDIA, PA 19063 USA SN 1042-7260 J9 J ZOO WILDLIFE MED JI J. Zoo Wildl. Med. PD DEC PY 2000 VL 31 IS 4 BP 441 EP 451 PG 11 WC Veterinary Sciences SC Veterinary Sciences GA 440XZ UT WOS:000169203100001 PM 11428391 ER PT J AU Schmitt, DL Hardy, DA Montali, RJ Richman, LK Lindsay, WA Isaza, R West, G AF Schmitt, DL Hardy, DA Montali, RJ Richman, LK Lindsay, WA Isaza, R West, G TI Use of famciclovir for the treatment of endotheliotrophic herpesvirus infections in Asian elephants (Elephas maximus) SO JOURNAL OF ZOO AND WILDLIFE MEDICINE LA English DT Article DE elephant; Elephas maximus; endothelial inclusion body disease (EIBD); famciclovir; herpesvirus; penciclovir AB Two juvenile Asian elephants (Elephas maximus) presented with an acute onset of facial edema and lethargy. Examination of the oral cavity of each animal revealed cyanosis of the tip and distal margins of the tongue suggestive of endothelial inclusion body disease (EIBD) of elephants. Whole-blood samples were obtained, and polymerase chain reaction rests confirmed the presence of elephant herpesvirus. The animals were administered famciclovir (Famvir, SmithKline Beecham Pharmaceuticals, Philadelphia Pennsylvania 19101. USA), a potent human anti-herpes-virus drug, in the course of their disease, and recovery followed a treatment regime of 3-4 wk. These are the first known cases of elephants surviving EIBD. C1 SW Missouri State Univ, Springfield, MO 65804 USA. Dickerson Pk Zoo, Springfield, MO 65803 USA. Smithsonian Natl Zool Pk, Washington, DC 20008 USA. Johns Hopkins Sch Med, Baltimore, MD 21205 USA. Ctr Elephant Conservat, Polk City, FL 33868 USA. Kansas State Univ, Coll Vet Med, Dept Clin Sci, Manhattan, KS 66506 USA. San Antonio Zool Gardens & AquaRIUM, San Antonio, TX 78212 USA. RP Schmitt, DL (reprint author), SW Missouri State Univ, Springfield, MO 65804 USA. NR 10 TC 15 Z9 15 U1 2 U2 7 PU AMER ASSOC ZOO VETERINARIANS PI MEDIA PA 6 NORTH PENNELL ROAD, MEDIA, PA 19063 USA SN 1042-7260 J9 J ZOO WILDLIFE MED JI J. Zoo Wildl. Med. PD DEC PY 2000 VL 31 IS 4 BP 518 EP 522 PG 5 WC Veterinary Sciences SC Veterinary Sciences GA 440XZ UT WOS:000169203100010 PM 11428400 ER PT J AU Sherrill, J Spelman, LH Reidel, CL Montali, RJ AF Sherrill, J Spelman, LH Reidel, CL Montali, RJ TI Common cuttlefish (Sepia officinalis) mortality at the National Zoological Park: Implications for clinical management SO JOURNAL OF ZOO AND WILDLIFE MEDICINE LA English DT Article DE Sepia officinalis; common cuttlefish; pathology; clinical management; mantle ulcers; gram-negative bacteria ID CEPHALOPODS; REPRODUCTION; GENERATIONS; SQUID AB Six out of seven cuttlefish acquired by the Smithsonian National Zoological Park in July 1998 died before 1 November 1998. Postmortem examinations showed mantle ulcers, secondary bacterial infections, inanition, and cuttlebone fractures. The surviving cuttlefish developed a progressive focal mantle ulcer, was treated with oral chloramphenicol intermittently for 9 wk, and maintained a normal appetite and growth rate until death at 7 mo of age. The National Zoological Park pathology database showed signalments, histories, and causes of mortality of 186 common cuttlefish, each 1-14 mo old, that received gross and histologic examinations; for example, the largest group of cuttlefish of known sex, age, and body weight at postmortem were 7-9 mo old and weighed an average of 376.2 g (males, n = 18) and 299.0 g (females, n = 15). Many cuttlefish had multiple pathologic diagnoses. Significant diseases included inflammation and secondary bacterial infections, especially gastrointestinal, cardiovascular, respiratory, reproductive, and ophthalmic, and septicemia due to Vibrio spp. or other gram-negative bacteria. Mantle lesions, including ulceration/ dermatitis, abscess/granuloma, necrosis/fibrosis/cellulitis, and laceration/abrasion/erosion, were also identified, along with inanition, cuttlebone lesions, and trauma. Mantle lesions were associated with secondary bacterial infections and death. On the basis of this information, if captive cuttlefish behavior creates risk for development of mantle lesions, administration of antibiotics effective against gram-negative bacteria may delay or halt disease progression. Cuttlefish exhibits require proper design, husbandry, economic resources, and staffing to minimize disease syndromes and mortality. C1 Smithsonian Inst, Natl Zool Pk, Dept Anim Hlth, Washington, DC 20008 USA. Smithsonian Inst, Natl Zool Pk, Dept Invertebrates, Washington, DC 20008 USA. Smithsonian Inst, Natl Zool Pk, Dept Pathol, Washington, DC 20008 USA. RP Sherrill, J (reprint author), Aquarium Pacific, Dept Husb, 100 Aquarium Way, Long Beach, CA 90802 USA. NR 37 TC 10 Z9 10 U1 0 U2 7 PU AMER ASSOC ZOO VETERINARIANS PI YULEE PA 581705 WHITE OAK ROAD, YULEE, FL 32097 USA SN 1042-7260 EI 1937-2825 J9 J ZOO WILDLIFE MED JI J. Zoo Wildl. Med. PD DEC PY 2000 VL 31 IS 4 BP 523 EP 531 PG 9 WC Veterinary Sciences SC Veterinary Sciences GA 440XZ UT WOS:000169203100011 PM 11428401 ER PT J AU Reents-Budet, D AF Reents-Budet, D TI The lost chronicles of the Maya kings SO LATIN AMERICAN ANTIQUITY LA English DT Book Review C1 Smithsonian Inst, Ctr Materials Res & Educ, Washington, DC 20560 USA. RP Reents-Budet, D (reprint author), Smithsonian Inst, Ctr Materials Res & Educ, Washington, DC 20560 USA. NR 1 TC 1 Z9 1 U1 0 U2 1 PU SOC AMER ARCHAEOLOGY PI WASHINGTON PA 900 SECOND ST., NE STE 12, WASHINGTON, DC 20002-3557 USA SN 1045-6635 J9 LAT AM ANTIQ JI Lat. Am. Antiq. PD DEC PY 2000 VL 11 IS 4 BP 417 EP 419 DI 10.2307/972005 PG 3 WC Archaeology SC Archaeology GA 384LX UT WOS:000165945100006 ER PT J AU Kalfatovic, MR AF Kalfatovic, MR TI Yes Yoko Ono. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst Libs, Washington, DC USA. RP Kalfatovic, MR (reprint author), Smithsonian Inst Libs, Washington, DC USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD DEC PY 2000 VL 125 IS 20 BP 124 EP 124 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA 385ZL UT WOS:000166035000055 ER PT J AU Riley, S AF Riley, S TI Protect and defend. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst Lib, Washington, DC USA. RP Riley, S (reprint author), Smithsonian Inst Lib, Washington, DC USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD DEC PY 2000 VL 125 IS 20 BP 190 EP 190 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA 385ZL UT WOS:000166035000310 ER PT J AU Lang, MA Hines, AH AF Lang, MA Hines, AH TI Smithsonian Institution underwater research SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Article ID MASS MORTALITY; CORAL C1 Smithsonian Inst, Off Secretary Sci, Washington, DC 20560 USA. Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. RP Lang, MA (reprint author), Smithsonian Inst, Off Secretary Sci, Washington, DC 20560 USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU MARINE TECHNOLOGY SOC INC PI WASHINGTON PA C/O I CLAYION MATTHEWS, 1828 L ST, NW, 9TH FL, WASHINGTON, DC 20036 USA SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD WIN PY 2000 VL 34 IS 4 BP 50 EP 60 PG 11 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA 396UN UT WOS:000166655000007 ER PT J AU Adams, RMM Mueller, UG Schultz, TR Norden, B AF Adams, RMM Mueller, UG Schultz, TR Norden, B TI Agro-predation: usurpation of attine fungus gardens by Megalomyrmex ants SO NATURWISSENSCHAFTEN LA English DT Article ID ANCESTRAL CHARACTER STATES; ATTA-CEPHALOTES L; LEAF-CUTTING-ANT; GROWING ANTS; FORMICIDAE; COLONY; HYMENOPTERA AB A new ant species of Megalomyrmex conducts mass raids to usurp gardens of the fungus-growing ant Cyphomyrmex longiscapus, then lives in the gardens and consumes the cultivated fungus. Unlike attine ants, however, Megalomyrvnex sp. does not forage for substrate to manure the gardens; therefore, when gardens become depleted, Megalomyrmex sp. must locate and usurp new gardens. Megalomyrmex sp. workers feed their larvae with attine brood, but only after removing the fungal mycelium that covers the attine larval integument, suggesting that this fungal coat may provide partial protection against other predators. Unlike other known Megalomyrmex species, which coexist as social parasites in attine colonies, Megalomyrmex sp. expels its attine hosts during the garden raids. Megalomyrmex sp. thus maintains a unique agro-predatory lifestyle that is described here for the first time. C1 Univ Texas, Sect Integrat Biol, Austin, TX 78712 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Entomol, MRC 188, Washington, DC 20560 USA. RP Adams, RMM (reprint author), Univ Texas, Sect Integrat Biol, Austin, TX 78712 USA. RI Adams, Rachelle/J-8846-2013 OI Adams, Rachelle/0000-0002-0918-9861 NR 42 TC 32 Z9 34 U1 0 U2 8 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0028-1042 J9 NATURWISSENSCHAFTEN JI Naturwissenschaften PD DEC PY 2000 VL 87 IS 12 BP 549 EP 554 DI 10.1007/s001140050777 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 386JL UT WOS:000166057700008 PM 11198197 ER PT J AU DiMichele, WA Chaney, DS Dixon, WH Nelson, WJ Hook, RW AF DiMichele, WA Chaney, DS Dixon, WH Nelson, WJ Hook, RW TI An Early Permian coastal flora from the Central Basin Platform of Gaines County, West Texas SO PALAIOS LA English DT Article ID CLEAR-FORK; TRANSITION AB Fossil plants are abundant in dolomite of the Clear Fork Group (Leonardian; late Early Permian) in the North Robertson Unit of the Robertson Clear Fork oil field of Gaines County, West Texas. The unit is a portion of the Larger Robertson field. Thirty-seven separate collections were made from drill cores taken in three wells, spanning an interval 300 m thick from a depth below the surface of > 2000 m. The flora is depauperate, comprised of Comia sp. (most abundant), Taeniopteris sp, Delnortea abbottiae, callipterid-like foliage of uncertain affinity, calamite stems, and unidentified foliage of cycad-like character. Plants occur in discrete intervals that are a fete cm to 3 m thick and have limited lateral continuity (less then 0.5 km). Plant-bearing dolomites contain interspersed fossil roots and burrows, weakly developed soil horizons, thin coaly accumulations of organic material, and pedogenic and collapse breccias. Fusain is common throughout. Between. the plant-bearing layers are heavily bioturbated dolomites with anhydrite-filled burrows, interpreted as Lagoonal to shallow subtidal in origin, up to 50 m thick. Contacts between marine units and plant-bearing beds are sharp. The North Robertson Unit and the field is believed to be internal to the Central Basin Platform and bordered by a shallow seaway to the east. The Central Basin Platform probably represented a broad peninsula between. the Midland Basin. to the east and the Delaware Basin. to the west. The site probably consisted of innumerable little islands separated by a network of waterways. Plants occur in "island complexes" consisting of deposits formed in. ponded water, beach fronts, and lagoons. Vegetation. must have been tolerant of salt or salt spray, seasonal drought, wind, and storms; all species were robust in. construction, with either thick leaves or heavy cuticles. This flora, although clearly allied with other Early Permian floras fi om western North America, is sufficiently peculiar to indicate that habitat differentiation was well developed within the tropical lowlands during the Late Paleozoic. C1 Smithsonian Inst, Museum Natl Hist Nat, Dept Paleobiol, Washington, DC 20560 USA. Illinois State Geol Survey, Champaign, IL 61820 USA. Univ Texas, Texas Mem Museum, Austin, TX 78758 USA. RP DiMichele, WA (reprint author), Smithsonian Inst, Museum Natl Hist Nat, Dept Paleobiol, Washington, DC 20560 USA. RI DiMichele, William/K-4301-2012 NR 31 TC 24 Z9 25 U1 3 U2 4 PU SEPM-SOC SEDIMENTARY GEOLOGY PI TULSA PA 1731 E 71ST STREET, TULSA, OK 74136-5108 USA SN 0883-1351 J9 PALAIOS JI Palaios PD DEC PY 2000 VL 15 IS 6 BP 524 EP 534 DI 10.2307/3515616 PG 11 WC Geology; Paleontology SC Geology; Paleontology GA 386EG UT WOS:000166046700004 ER PT J AU Eble, GJ AF Eble, GJ TI Contrasting evolutionary flexibility in sister groups: disparity and diversity in Mesozoic atelostomate echinoids SO PALEOBIOLOGY LA English DT Review ID FOSSIL RECORD; TAXONOMIC DIVERSITY; SPATANGOID ECHINOIDS; REGULAR ECHINOIDS; EXTINCTION; PATTERNS; END; DIVERSIFICATION; PERSPECTIVE; SELECTIVITY AB Temporal asymmetries in clade histories have often been studied in lower Paleozoic radiations. Post-Paleozoic patterns, however, are less well understood. In this paper, disparity and diversity changes in Mesozoic heart urchins were analyzed at the ordinal level, with contrasts among the sister groups Holasteroida and Spatangoida, their paraphyletic stem group Disasteroida, and the more inclusive clade, the superorder Atelostomata. A 38-dimensional landmark-based morphospace representing test architecture was used to describe morphological evolution in terms of total variance and total range. Discordances between disparity and diversity were evident and were expressed both as deceleration in morphological diversification in all groups and as disproportionately higher disparity early in the histories of the Atelostomata, Holasteroida, and Spatangoida. The finding that the early atelostomate disparity peak coincides with the origin of the orders Holasteroida and Spatangoida lends support to the perception of orders as semi-independent entities in the biological hierarchy and as meaningful proxies for morphological distinctness. A comparison of holasteroid and spatangoid responses to the end-Cretaceous mass extinction revealed morphological selectivity. Paleocene spatangoid survivors showed no change in disparity relative to the Campanian-Maastrichtian sample, suggesting nonselectivity. Holasteroids suffered a pronounced loss in disparity (despite a rather high Late Cretaceous level of disparity), indicating morphological selectivity of extinction. Partitioning of disparity into plastral and nonplastral components, reflecting different degrees of developmental entrenchment and functionality, suggests that the origin of holasteroids and spatangoids is more consistent with an exploration of the developmental flexibility of nonplastral constructions than with uniform ecospace occupation. Within groups, several patterns were also most consistent with intrinsic controls. For plastral landmarks, there is an apparent increase in developmental modularity and decrease in developmental constraint from disasteroids to holasteroids and spatangoids. For nonplastral landmarks, no substantial change in disparity was observed from disasteroids to holasteroids and spatangoids, suggesting the maintenance of a developmental constraint despite the passage of time and ecological differentiation. More generally, this study suggests that certain topologies of disparity and evolutionary mechanisms potentially characteristic of the lower Paleozoic radiations of higher taxa (e.g., developmental flexibility) need not be confined to any given time period or hierarchical level. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Palaeontol, Washington, DC 20560 USA. Santa Fe Inst, Santa Fe, NM 87501 USA. RP Eble, GJ (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Palaeontol, MRC-121, Washington, DC 20560 USA. NR 114 TC 70 Z9 71 U1 1 U2 3 PU PALEONTOLOGICAL SOC INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 USA SN 0094-8373 J9 PALEOBIOLOGY JI Paleobiology PD WIN PY 2000 VL 26 IS 1 BP 56 EP 79 DI 10.1666/0094-8373(2000)026<0056:CEFISG>2.0.CO;2 PG 24 WC Biodiversity Conservation; Ecology; Evolutionary Biology; Paleontology SC Biodiversity & Conservation; Environmental Sciences & Ecology; Evolutionary Biology; Paleontology GA 298PY UT WOS:000086149400005 ER PT J AU Nave, G Griesmann, U AF Nave, G Griesmann, U TI New energy levels and classifications of spectral lines from neutral and singly-ionized dysprosium (Dy I and dy II) SO PHYSICA SCRIPTA LA English DT Article ID VACUUM ULTRAVIOLET; HOLLOW-CATHODE AB We present new energy-level classifications for over 400 lines in the spectra of neutral and singly-ionized dysprosium. These lines were observed using Fourier transform spectrometry of high current hollow cathode lamps and cover the wavelength range 230 nm to 1.6 mum. They were classified by 43 new energy levels of Dy I and 24 new energy levels of Dy II. The standard uncertainty of the energy levels and the strongest lines is estimated at 0.005 cm(-1). C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Nave, G (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 20 TC 4 Z9 5 U1 1 U2 2 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PD DEC PY 2000 VL 62 IS 6 BP 463 EP 473 DI 10.1238/Physica.Regular.062a00463 PG 11 WC Physics, Multidisciplinary SC Physics GA 382LK UT WOS:000165823600005 ER PT J AU Crescimanno, M Koay, CG Peterson, R Walsworth, R AF Crescimanno, M Koay, CG Peterson, R Walsworth, R TI Analytical estimate of the critical velocity for vortex pair creation in trapped Bose condensates SO PHYSICAL REVIEW A LA English DT Article ID SUPERFLUID HE-4; DISSIPATION; FLUIDS; MODEL AB We use a Thomas-Fermi approximation that includes the leading kinetic terms due to fluid motion to estimate analytically the critical velocity for the formation of vortex pairs in harmonically trapped Bose-Einstein condensates. We find rough agreement between this analytical estimate and recent experiments on trapped sodium gas condensates. C1 Youngstown State Univ, Dept Phys & Astron, Youngstown, OH 44555 USA. Berea Coll, Dept Phys, Berea, KY 40404 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Crescimanno, M (reprint author), Youngstown State Univ, Dept Phys & Astron, Youngstown, OH 44555 USA. NR 29 TC 17 Z9 17 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD DEC PY 2000 VL 62 IS 6 AR 063612 DI 10.1103/PhysRevA.62.063612 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 380JC UT WOS:000165697200090 ER PT J AU Derevianko, A Dalgarno, A AF Derevianko, A Dalgarno, A TI Long-range interaction of two metastable rare-gas atoms SO PHYSICAL REVIEW A LA English DT Article ID ABSOLUTE TRANSITION-PROBABILITIES; DYE LASER SPECTROSCOPY; MANY-BODY CALCULATIONS; ALKALI-METAL ATOMS; DIPOLE POLARIZABILITIES; OSCILLATOR-STRENGTHS; XENON; NEON; COEFFICIENTS; COLLISIONS AB We present semiempirical calculations of long-range van der Waals interactions for two interacting metastable rare-gas atoms Ne through Xe. Dispersion coefficients C-6 are obtained for homonuclear molecular potentials asymptotically connecting to the ns(3/2)(2) + ns(3/2)(2) atomic states. The estimated uncertainty of the calculated C-6 dispersion coefficients is 4%. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. RP Derevianko, A (reprint author), Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. RI Derevianko, Andrei/G-8356-2011 NR 27 TC 14 Z9 14 U1 0 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD DEC PY 2000 VL 62 IS 6 AR 062501 DI 10.1103/PhysRevA.62.062501 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 380JC UT WOS:000165697200032 ER PT J AU Hessmo, B Sjoqvist, E AF Hessmo, B Sjoqvist, E TI Quantal phase for nonmaximally entangled photons SO PHYSICAL REVIEW A LA English DT Article ID PANCHARATNAM PHASE; TOPOLOGICAL PHASE; GEOMETRIC PHASE; POLARIZED-LIGHT; INTERFEROMETRY; INTERFERENCE; INEQUALITIES; NONLOCALITY; STATES; SHIFT AB We calculate the Pancharatnam phase difference obtained when entangled two-photon states interfere. This phase depends nontrivially on the degree of entanglement between the photons forming the two-photon state. We outline an experiment where the entanglement dependence of the two-photon phase may be studied interferometrically. Also we propose how a cyclic version of this phase may be useful for implementing an efficient quantum gate. C1 Uppsala Univ, Dept Quantum Chem, SE-75120 Uppsala, Sweden. Univ Innsbruck, Inst Expt Phys, A-6020 Innsbruck, Austria. Harvard Smithsonian Ctr Astrophys, ITAMP, Cambridge, MA 02138 USA. Osterreich Univ, Inst Atom, A-1020 Vienna, Austria. RP Uppsala Univ, Dept Quantum Chem, POB 518, SE-75120 Uppsala, Sweden. EM hessmo@kvac.uu.se; eriks@kvac.uu.se RI Hessmo, Bjorn/G-2031-2012 NR 26 TC 26 Z9 26 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD DEC PY 2000 VL 62 IS 6 AR 062301 DI 10.1103/PhysRevA.62.062301 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 380JC UT WOS:000165697200016 ER PT J AU Humphrey, MA Phillips, DF Walsworth, RL AF Humphrey, MA Phillips, DF Walsworth, RL TI Double-resonance frequency shift in a hydrogen maser SO PHYSICAL REVIEW A LA English DT Article ID QUANTUM-MECHANICS; ATOMIC-HYDROGEN; SPIN AB We use the dressed-atom formalism to calculate the frequency shift in a hydrogen maser induced by applied radiation near the Zeeman frequency, and find excellent agreement with a previous calculation made in the bare-atom basis. The maser oscillates on the DeltaF=1, Deltam(F),=0 hyperfine transition, while the applied field is swept through the F=1, Deltam(F)=+/-1 Zeeman resonance. We determine the effect of die applied field on the Zeeman levels using the dressed-atom picture, and then calculate the maser frequency shift by coupling the dressed states to the microwave cavity. Qualitatively, the dressed-atom analysis gives a simpler physical interpretation of this double-resonance process, which has applications in precision hydrogen Zeeman spectroscopy, e.g., in fundamental symmetry tests. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Humphrey, MA (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 19 TC 55 Z9 55 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD DEC PY 2000 VL 62 IS 6 AR 063405 DI 10.1103/PhysRevA.62.063405 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 380JC UT WOS:000165697200076 ER PT J AU Finn, BS AF Finn, BS TI Museums and American intellectual life, 1876-1926 SO PUBLIC HISTORIAN LA English DT Book Review C1 Smithsonian Inst, Washington, DC 20560 USA. RP Finn, BS (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU UNIV CALIF PRESS PI BERKELEY PA JOURNALS DEPT 2120 BERKELEY WAY, BERKELEY, CA 94720 USA SN 0272-3433 J9 PUBL HISTORIAN JI Public Hist. PD WIN PY 2000 VL 22 IS 1 BP 65 EP 68 PG 4 WC History SC History GA 291TE UT WOS:000085751500012 ER PT J AU Arnoldi, MJ AF Arnoldi, MJ TI Wild animals and heroic men: Visual and verbal arts in the Sogo bo masquerades of Mali SO RESEARCH IN AFRICAN LITERATURES LA English DT Article C1 Smithsonian Inst, Washington, DC 20560 USA. RP Arnoldi, MJ (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU INDIANA UNIV PRESS PI BLOOMINGTON PA 601 N MORTON STREET, BLOOMINGTON, IN 47404-3797 USA SN 0034-5210 J9 RES AFR LITERATURES JI Res. Afr. Lit. PD WIN PY 2000 VL 31 IS 4 BP 63 EP 75 PG 13 WC Literature, African, Australian, Canadian SC Literature GA 376QV UT WOS:000165469000006 ER PT J AU Coelho, VR Williams, AB Rodrigues, SD AF Coelho, VR Williams, AB Rodrigues, SD TI Trophic strategies and functional morphology of feeding appendages, with emphasis on setae, of Upogebia omissa and Pomatogebia operculata (Decapoda : Thalassinidea : Upogebiidae) SO ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY LA English DT Article DE shrimp; filter feeder; deposit feeder; pereiopods ID GROOMING BEHAVIOR; CRUSTACEA; ECOLOGY; CLASSIFICATION; MOUTHPARTS; PEREIOPODS; MODES AB Although species of Upogebiidae historically have been considered filter feeders, recent studies show that many species of this group also deposit feed. In this study, the degrees of trophic specialization of two species of this family, Upogebia omissa and Pomatogebia operculata, were analysed. Feeding mechanisms, stomach contents and morphology of the feeding appendages, with emphasis on setae, were examined. U. omissa, found in sandy substrate, is a generalistic feeder while P. operculata inhabits burrows inside corals, being more specialized in filter feeding. Only 21% of the 57 setal types described were common to both species. Setal types were clustered in three main categories: plumed, serrate and plumodenticulate. No simple setae were found. P. operculata has lower setal diversity, with higher ratio of plumodenticulate to serrate setal types than U. omissa. The 1st and 2nd pereiopods have an important role in collecting food. The mouthparts have two main Functions: to brush and retain particles so that food can be transported from the pereiopods to the mouth. Generally in these appendages, the dactyli and basal endites are responsible for brushing particles and the meri and coxal endites for particle retention. The diversity of setal types and complexity of their distribution on the appendages may be related to the necessity to select and triturate particles prior to ingestion, reflecting the differences in trophic strategies utilized by U. omissa and P. operculata. Setal characters appear to be indicators of the relative importance of a specific feeding mode for species of this group. (C) 2000 The Linnean Society or London. C1 Univ Sao Paulo, Inst Biociencias, Dept Zool, BR-05422970 Sao Paulo, Brazil. Univ Sao Paulo, Inst Biociencias, Dept Ecol Geral, BR-05422970 Sao Paulo, Brazil. Smithsonian Inst, Natl Museum Nat Hist, Natl Marine Fisheries Serv, Systemat Lab, Washington, DC 20560 USA. RP Coelho, VR (reprint author), Columbia Univ, Biosphere 2 Ctr, 32540 Biosphere Rd, Oracle, AZ 85623 USA. NR 45 TC 19 Z9 19 U1 1 U2 6 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0024-4082 J9 ZOOL J LINN SOC-LOND JI Zool. J. Linn. Soc. PD DEC PY 2000 VL 130 IS 4 BP 567 EP 602 DI 10.1111/j.1096-3642.2000.tb02202.x PG 36 WC Zoology SC Zoology GA 384LU UT WOS:000165944800006 ER PT J AU Anderson, FE AF Anderson, FE TI Phylogenetic relationships among loliginid squids (Cephalopoda : Myopsida) based on analyses of multiple data sets SO ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY LA English DT Article DE Loliginidae; total evidence; morphology; 16S-cytochrome c oxidase I; allozymes; phylogeny; maximum parsimony ID EVOLUTIONARY TREES; INCONGRUENCE; PARSIMONY; CTENOPTERYX; SEQUENCES; PRINCIPLE; REVISION; TESTS; GAHI AB The phylogenetic relationships among the loliginid squids, a species-rich group of shallow-water muscular squids, have been investigated recently using several approaches, including allozyme electrophoresis and analyses of morphological and DNA sequence data, vet no consensus has been reached. This study examines the effects of combining multiple data sets (morphology, allozymes and DNA sequence data from two mitochondrial genes) on estimates of loliginid phylogeny. Various data combinations were analysed under three maximum parsimony weighting schemes: equal weights for all characters, successive approximations and implicit weights parsimony. When feasible, support for branches within trees Tvas assessed with nonparametric bootstrapping and decay analysis. Some ingroup relationships were consistent across all analyses, but relationships among outgroup taxa and basal ingroup taxa varied. Combining data increased bootstrap support for several nodes. Methods that downweight highly variable characters (i.e. successive approximations and implicit weights parsimony) produced very similar trees which included two major clades: a clade consisting of all species sampled from American waters (except Sepioteuthis), and a clade of several east Atlantic species (Loligo forbesi Steenstrup, Loligo vulgaris Lamarck and Loligo reynaudi d'Orbigny) plus several Indo-West Pacific species in the genera Uroteuthis , and Loliolus. The Sepioteuthis species occupied a basal position within Loliginidae, but Sepioteuthis itself was not always monophyletic. The position of a clade of a few Lolliguncula species and Loligo (Alloteuthis) also varied across analyses. A new loliginid classification is proposed based on these findings. (C) 2000 The Linnean Society of London. C1 Smithsonian Inst, Lab Mol Systemat, Suitland, MD 20746 USA. RP Anderson, FE (reprint author), So Illinois Univ, Dept Zool, Carbondale, IL 62901 USA. NR 71 TC 26 Z9 27 U1 1 U2 10 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0024-4082 J9 ZOOL J LINN SOC-LOND JI Zool. J. Linn. Soc. PD DEC PY 2000 VL 130 IS 4 BP 603 EP 633 DI 10.1006/zjls.2000.0242 PG 31 WC Zoology SC Zoology GA 384LU UT WOS:000165944800007 ER PT J AU Garay, LJ Anglin, JR Cirac, JI Zoller, P AF Garay, LJ Anglin, JR Cirac, JI Zoller, P TI Sonic analog of gravitational black holes in Bose-Einstein condensates SO PHYSICAL REVIEW LETTERS LA English DT Article ID HAWKING RADIATION; DARK SOLITONS; ATOM LASER; EVAPORATION; VORTICES; HORIZONS; CREATION; HE-3 AB It is shown that, in dilute-gas Bose-Einstein condensates, there exist both dynamically stable and unstable configurations which, in the hydrodynamic limit, exhibit a behavior resembling that of gravitational black holes. The dynamical instabilities involve creation of quasiparticle pairs in positive and negative energy states, as in the well-known suggested mechanism for black-hole evaporation. We propose a scheme to generate a stable sonic black hole in a ring trap. C1 Univ Innsbruck, Inst Theoret Phys, A-6020 Innsbruck, Austria. CSIC, Inst Matemat & Fis Fundamental, E-28006 Madrid, Spain. Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02135 USA. RP Garay, LJ (reprint author), Univ Innsbruck, Inst Theoret Phys, Technikerstr 25, A-6020 Innsbruck, Austria. RI Garay, Luis J./C-2544-2013; Zoller, Peter/O-1639-2014 OI Garay, Luis J./0000-0002-3943-7782; Zoller, Peter/0000-0003-4014-1505 NR 27 TC 283 Z9 285 U1 1 U2 12 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 27 PY 2000 VL 85 IS 22 BP 4643 EP 4647 DI 10.1103/PhysRevLett.85.4643 PG 5 WC Physics, Multidisciplinary SC Physics GA 377ZP UT WOS:000165556600001 ER PT J AU Barlow, NG Boyce, JM Costard, FM Craddock, RA Garvin, JB Sakimoto, SEH Kuzmin, RO Roddy, DJ Soderblom, LA AF Barlow, NG Boyce, JM Costard, FM Craddock, RA Garvin, JB Sakimoto, SEH Kuzmin, RO Roddy, DJ Soderblom, LA TI Standardizing the nomenclature of Martian impact crater ejecta morphologies SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID WIND EROSION; MARS; DEPOSITS; DEGRADATION; VOLATILES; HIGHLANDS; LATITUDE; REGIONS; BASIN; WATER AB The Mars Crater Morphology Consortium recommends the use of a standardized nomenclature system when discussing Martian impact crater ejecta morphologies. The system utilizes nongenetic descriptors to identify the various ejecta morphologies seen on Mars. This system is designed to facilitate communication and collaboration between researchers. Crater morphology databases will be archived through the U.S. Geological Survey in Flagstaff, where a comprehensive catalog of Martian crater morphologic information will be maintained. C1 Univ Cent Florida, Dept Phys, Orlando, FL 32816 USA. NASA, Headquarters, Off Space Sci, Washington, DC 20546 USA. CNRS, Lab Geol Dynam Terre & Planetes, UMR 8616, F-91405 Orsay, France. Smithsonian Inst, Natl Air & Space Museum, Ctr Earth & Planetary Studies, Washington, DC 20560 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Russian Acad Sci, Vernadsky Inst, Moscow 117975, Russia. US Geol Survey, Flagstaff, AZ 86001 USA. RP Barlow, NG (reprint author), Univ Cent Florida, Dept Phys, MAP 310, Orlando, FL 32816 USA. RI Craddock, Robert/B-3884-2013 NR 42 TC 107 Z9 107 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD NOV 25 PY 2000 VL 105 IS E11 BP 26733 EP 26738 DI 10.1029/2000JE001258 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 376AL UT WOS:000165435600003 ER PT J AU Rahbek, C Graves, GR AF Rahbek, C Graves, GR TI Detection of macro-ecological patterns in South American hummingbirds is affected by spatial scale SO PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES LA English DT Article DE hummingbirds; latitude; scaling; species-richness gradients; topography; Trochilidae ID SPECIES-AREA RELATIONSHIP; LATITUDINAL GRADIENTS; NEW-WORLD; REGIONAL PROCESSES; GLOBAL PATTERNS; RICHNESS; DIVERSITY; BIRDS; COMMUNITIES; PRODUCTIVITY AB Scale is widely recognized as a fundamental conceptual problem in biology, but the question of whether species-richness patterns var) with scale is often ignored in macro-ecological analyses, despite the increasing application of such data in international conservation programmes. We tested for scaling effects in species-richness gradients with spatially scaled data for 241 species of South American hummingbirds (Trochilidae). Analyses revealed that scale matters above and beyond the effect of quadrat area. Species richness was positively correlated with latitude and topographical relief at ten different spatial scales spanning two orders of magnitude (ca. 12 300 tu ra. 1 225 000 km(2)). Surprisingly, when the influence of topography was removed, the conditional variation in species richness explained by latitude fell Precipitously to insignificance at coarser spatial scales. The perception of macro-ecological pattern thus depends directly upon the scale of analysis. Although our results suggest there is no single correct scale For macro-ecological analyses, the averaging effect of quadrat sampling at coarser geographical scales obscures the fine structure of species-richness gradients and localized richness peaks, decreasing the power of statistical tests to discriminate the causal agents of regional richness gradients. Ideally the scale of analysis should be varied systematically to provide the optimal resolution of macro-ecological pattern. C1 Univ Copenhagen, Zool Museum, DK-2100 Copenhagen O, Denmark. Smithsonian Inst, Natl Museum Nat Hist, Dept Vertebrate Zool, Washington, DC 20560 USA. RP Rahbek, C (reprint author), Univ Copenhagen, Zool Museum, Universitetsparken 15, DK-2100 Copenhagen O, Denmark. EM graves.gary@mnmh.si.edu RI Rahbek, Carsten/D-9372-2013; Rahbek, Carsten/L-1129-2013; publist, CMEC/C-3010-2012; publicationpage, cmec/B-4405-2017 NR 64 TC 80 Z9 83 U1 2 U2 19 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 0962-8452 J9 P ROY SOC B-BIOL SCI JI Proc. R. Soc. B-Biol. Sci. PD NOV 22 PY 2000 VL 267 IS 1459 BP 2259 EP 2265 PG 7 WC Biology; Ecology; Evolutionary Biology SC Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Evolutionary Biology GA 375MB UT WOS:000165402100004 PM 11413641 ER PT J AU Weldon, PJ AF Weldon, PJ TI Avian chemical defense: Toxic birds not of a feather SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Editorial Material ID HOMOBATRACHOTOXIN; ALKALOIDS; SKIN C1 Smithsonian Inst, Conservat & Res Ctr, Front Royal, VA 22630 USA. RP Weldon, PJ (reprint author), Smithsonian Inst, Conservat & Res Ctr, 1500 Remount Rd, Front Royal, VA 22630 USA. NR 18 TC 9 Z9 9 U1 0 U2 5 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD NOV 21 PY 2000 VL 97 IS 24 BP 12948 EP 12949 DI 10.1073/pnas.97.24.12948 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 376UZ UT WOS:000165476300007 PM 11087849 ER PT J AU Dumbacher, JP Spande, TF Daly, JW AF Dumbacher, JP Spande, TF Daly, JW TI Batrachotoxin alkaloids from passerine birds: A second toxic bird genus (Ifrita kowaldi) from New Guinea SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID POISON FROGS DENDROBATIDAE; CHEMICAL DEFENSE; HOMOBATRACHOTOXIN AB Batrachotoxins, including many congeners not previously described, were detected, and relative amounts were measured by using HPLC-mass spectrometry, in five species of New Guinean birds of the genus Pitohui as well as a species of a second toxic bird genus, Ifrita kowaldi. The alkaloids, identified in feathers and skin, were hatrachotoxinin-A cis-crotonate (1), an allylically rearranged 16-acetate (2), which can form from 1 by sigmatropic rearrangement under basic conditions, batrachotoxinin-A and an isomer (3 and 3a, respectively), batrachotoxin (4), batrachotoxinin-A 3'-hydroxypentanoate (5), homobatrachotoxin (6), and mono- and dihydroxylated derivatives of homobatrachotoxin, The highest levels of batrachotoxins were generally present in the contour feathers of belly, breast, or legs in Pitohui dichrous, Pitohui kirhocephalus, and Ifrita kowaldi, Lesser amounts are found in head, back, tail, and wing feathers. Batrachotoxin (4) and homobatrachotoxin (6) were found only in feathers and not in skin. The levels of batrachotoxins varied widely for different populations of Pitohui and Ifrita, a result compatible with the hypothesis that these birds are sequestering toxins from a dietary source. C1 Smithsonian Inst, Natl Zool Pk, Genet Mol Lab, Washington, DC 20008 USA. NIDDKD, Bioorgan Chem Lab, NIH, Bethesda, MD 20892 USA. RP Dumbacher, JP (reprint author), Smithsonian Inst, Natl Zool Pk, Genet Mol Lab, 3001 Connecticut Ave NW, Washington, DC 20008 USA. NR 21 TC 70 Z9 74 U1 1 U2 19 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD NOV 21 PY 2000 VL 97 IS 24 BP 12970 EP 12975 DI 10.1073/pnas.200346897 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 376UZ UT WOS:000165476300016 PM 11035772 ER PT J AU Finoguenov, A David, LP Ponman, TJ AF Finoguenov, A David, LP Ponman, TJ TI An ASCA study of the heavy-element distribution in clusters of galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : abundances; galaxies : clusters : general; galaxies : evolution; intergalactic medium; supernovae : general; X-rays : galaxies ID X-RAY-SPECTRA; INTRACLUSTER MEDIUM ENRICHMENT; INITIAL MASS FUNCTION; HYDRA-A CLUSTER; 4 RICH CLUSTERS; ELLIPTIC GALAXIES; COOLING FLOWS; CHEMICAL EVOLUTION; PSPC OBSERVATIONS; POOR CLUSTERS AB We perform a spatially resolved X-ray spectroscopic study of a set of 11 relaxed clusters of galaxies observed by the ROSAT/PSPC and ASCA/SIS. Using a method, which corrects for the energy-dependent effects of the ASCA point-spread function based on ROSAT images, we constrain the spatial distribution of Ne, Si, S, and Fe in each cluster. Theoretical prescriptions for the chemical yields of Types Ia and II supernovae then allow determination of the Fe enrichment from both types of supernovae as a function of radius within each cluster. Using optical measurements from the literature, we also determine the iron mass-to-light ratio (IMLR) separately for Fe synthesized in both types of supernovae. For clusters with the best photon statistics, we find that the total Fe abundance decreases significantly with radius while the Si abundance is either flat or decreases less rapidly, resulting in an increasing Si/Fe ratio with radius. This result indicates a greater predominance of Type II supernova (SN) enrichment at large radii in clusters. On average, the IMLR synthesized within Type II SNe increases with radius within clusters, while the IMLR synthesized within Type Ia SNe decreases. At a fixed radius of 0.4 R-virial there is also a factor of 5 increase in the IMLR synthesized by Type II SNe between groups and clusters. This suggests that groups expelled as much as 90% of the Fe synthesized within Type II SNe at early times. All of these results are consistent with a scenario in which the gas was initially heated and enriched by Type II SN-driven galactic winds. Because of the high entropy of the preheated gas, SN II products are only weakly captured in groups. Gravitationally bound gas was then enriched with elements synthesized by Type Ia supernovae as gas-rich galaxies accreted onto clusters and were stripped during passage through the cluster core via density-dependent mechanisms (e.g., ram pressure ablation, galaxy harassment, etc.). We suggest that the high Si/Fe ratios in the outskirts of rich clusters may arise from enrichment by Type II SNe released to the intracluster medium via galactic starburst-driven winds. Low S/Fe ratios observed in clusters suggest metal-poor galaxies as a major source of SN II products. C1 Inst Astrophys, D-14882 Potsdam, Germany. Moscow Space Res Inst, Moscow 117810, Russia. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. RP Finoguenov, A (reprint author), Inst Astrophys, Sternwarte 16, D-14882 Potsdam, Germany. NR 72 TC 134 Z9 134 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2000 VL 544 IS 1 BP 188 EP 203 DI 10.1086/317173 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 381FH UT WOS:000165751300017 ER PT J AU Costantini, E Nicastro, F Fruscione, A Mathur, S Comastri, A Elvis, M Fiore, F Salvini, C Stirpe, GM Vignali, C Wilkes, B O'Brien, PT Goad, MR AF Costantini, E Nicastro, F Fruscione, A Mathur, S Comastri, A Elvis, M Fiore, F Salvini, C Stirpe, GM Vignali, C Wilkes, B O'Brien, PT Goad, MR TI The complex X-ray absorbers of NGC 3516 observed by BeppoSAX SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (NGC 3516); galaxies : Seyfert; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; SEYFERT-1 GALAXY NGC-3516; BROAD-LINE REGION; ABSORPTION-LINES; EMISSION-LINE; ASTRONOMY SATELLITE; ASCA OBSERVATIONS; ON-BOARD; VARIABILITY; SPECTRA AB In this paper we present the analysis of two broadband (0.1-150 keV) BeppoSAX observations of the Seyfert 1 galaxy NGC 3516. The two observations were taken 4 months apart, on 1996 November 8 and 1997 March 12. We report a dramatic change in the degree of obscuration of the central source between the two observations and propose, as possible explanations, transient absorption by either a stationary-state cloud of cold gas crossing the line of sight or a varying-state, initially neutral and dense amount of expanding gas with decreasing density and therefore decreasing opacity. We also report the detection of a second highly ionized absorber/emitter, which causes deep Fe XVII-XXII K edges at similar to7.8 keV to appear in both of the BeppoSAX spectra of NGC 3516 and possibly produces the soft X-ray continuum emission in the 1 keV blend of Fe L recombination lines detected during the epoch of heavy nuclear obscuration. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Osservatorio Astron Monteporzio, I-00040 Monte Porzio Catone, Italy. CNR, Ist Astrofis Spaziale, I-00133 Rome, Italy. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. Osservatorio Astron Bologna, I-40127 Bologna, Italy. Univ Bologna, Dipartimento Astron, I-40127 Bologna, Italy. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. RP Costantini, E (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Vignali, Cristian/J-4974-2012; Stirpe, Giovanna/O-9393-2015; Comastri, Andrea/O-9543-2015; OI Vignali, Cristian/0000-0002-8853-9611; Stirpe, Giovanna/0000-0002-3702-8731; Comastri, Andrea/0000-0003-3451-9970; Nicastro, Fabrizio/0000-0002-6896-1364; Wilkes, Belinda/0000-0003-1809-2364; Fiore, Fabrizio/0000-0002-4031-4157 NR 58 TC 14 Z9 14 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2000 VL 544 IS 1 BP 283 EP 292 DI 10.1086/317200 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 381FH UT WOS:000165751300024 ER PT J AU Psaltis, D Ozel, F DeDeo, S AF Psaltis, D Ozel, F DeDeo, S TI Photon propagation around compact objects and the inferred properties of thermally emitting neutron stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE relativity; stars : neutron; X-rays : stars ID SOFT GAMMA-REPEATERS; X-RAY; EMISSION; PULSARS; SURFACE; SPOTS; FIELD AB Anomalous X-ray pulsars, compact nonpulsing X-ray sources in supernova remnants, and X-ray bursters are three distinct types of sources for which there are viable models that attribute their X-ray spectra to thermal emission from the surface of a neutron star. Inferring the surface area of the emitting regions in such systems is crucial in assessing the viability of different models and in providing bounds on the radii of neutron stars. We show that the spectroscopically inferred areas of the emitting regions may be over- or underestimated by a factor of less than or similar to2, because of the three-dimensional geometry of the system and general relativistic light deflection, combined with the effects of phase averaging. Such effects make the determination of neutron star radii uncertain, especially when compared to the similar to5% level required for constraining the equation of state of neutron star matter. We also note that, for a given spectral shape, the inferred source luminosities and pulse fractions are anticorrelated because they depend on the same properties of the emitting regions, namely, their sizes and orientations. As a result, brighter sources have on average weaker pulsation amplitudes than fainter sources. We argue that this property can be used as a diagnostic tool in distinguishing between different spectral models. As an example, we show that the high inferred pulse fraction and brightness of the pulsar RXS J1708-40 are inconsistent with isotropic thermal emission from a neutron star surface. Finally, we discuss the implication of our results for surveys in the soft X-rays for young, cooling neutron stars in supernova remnants and show that the absence of detectable pulsations from the compact source at the center of Cas A (at a level of greater than or similar to 30%) is not a strong argument against its identification with a spinning neutron star. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Psaltis, D (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 30 TC 39 Z9 39 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2000 VL 544 IS 1 BP 390 EP 396 DI 10.1086/317208 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 381FH UT WOS:000165751300034 ER PT J AU Fiore, F Nicastro, F Savaglio, S Stella, L Vietri, M AF Fiore, F Nicastro, F Savaglio, S Stella, L Vietri, M TI Probing the warm intergalactic medium through absorption against gamma-ray burst X-ray afterglows SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; gamma rays : bursts; large-scale structure of universe ID ALPHA FOREST; CONSTRAINTS; BEPPOSAX; SPECTRA; GAS AB Gamma-ray burst (GRB) afterglows close to their peak intensity are among the brightest X-ray sources in the sky. Despite their fast power-law-like decay, when fluxes are integrated from minutes up to hours after the GRB event, the corresponding number counts (log N-log F relation) far exceed those of any other high-redshift (z > 0.5) source, the flux of which is integrated over the same time interval. We discuss how to use X-ray afterglows of GRBs as distant beacons to probe the warm (10(5) K < T< 10(7) K) intergalactic matter in filaments and outskirts of clusters of galaxies by means of absorption features, the "X-ray forest." According to current cosmological scenarios, this matter may comprise 30%-40% of the baryons in the universe at z < 1. Present-generation X-ray spectrometers such as those on Chandra and XMM-Newton can detect it along most GRBs' lines of sight, provided afterglows are observed soon enough (within hours) after the burst. A dedicated medium-sized X-ray telescope (effective area 0.1 m(2)) with pointing capabilities similar to that of Swift (minutes) and high spectral resolution (E/DeltaE greater than or similar to 300) would be very well suited to exploit the new diagnostic and study the physical conditions in the universe at the critical moment when structure is being formed. C1 Osservatorio Astron Roma, I-00044 Monte Porzio Catone, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Roma Tre, Dipartimento Fis, I-00146 Rome, Italy. RP Fiore, F (reprint author), Osservatorio Astron Roma, Via Frascati 33, I-00044 Monte Porzio Catone, Italy. OI Nicastro, Fabrizio/0000-0002-6896-1364; Savaglio, Sandra/0000-0003-2354-3238; Fiore, Fabrizio/0000-0002-4031-4157 NR 30 TC 21 Z9 21 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2000 VL 544 IS 1 BP L7 EP L10 DI 10.1086/317286 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 381GB UT WOS:000165753000002 ER PT J AU Garnavich, PM Loeb, A Stanek, KZ AF Garnavich, PM Loeb, A Stanek, KZ TI Resolving gamma-ray burst 000301C with a gravitational microlens SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; gravitational lensing ID 28 FEBRUARY 1997; RELATIVISTIC FIREBALLS; RADIO AFTERGLOW; EMISSION; MODELS; SIZE; JET AB The afterglow of the gamma-ray burst (GRB) 000301C exhibited achromatic, short-timescale variability that is difficult to reconcile with the standard relativistic shock model. We interpret the observed light curves as a microlensing event superposed on power-law flux decays typical of afterglows. In general, a relativistic GRB shock appears on the sky as a thin ring expanding at a superluminal speed. Initially the ring is small relative to its angular separation from the lens, and so its flux is magnified by a constant factor. As the ring grows and sweeps across the lens, its magnification reaches a maximum. Subsequently, the flux gradually recovers its unlensed value. This behavior involves only three free parameters in its simplest formulation and was predicted theoretically by A. Loeb & R. Perna. Fitting the available R-band photometric data of GRB 000301C to a simple model of the microlensing event and a broken power law for the afterglow, we find reasonable values for all the parameters and a reduced chi (2)/degrees of freedom parameter of 1.48 compared with 2.99 for the broken power-law fit alone. The peak magnification of similar to2 occurred 3.8 days after the burst. The entire optical to IR data imply a width of the GRB ring of order 10% of its radius, similar to theoretical expectations. The angular resolution provided by microlensing is better than a microarcsecond. We infer a mass of approximately 0.5 M. for a lens located halfway to the source at z(s) = 2.04. A galaxy 2" from GRB 000301C might be the host of the stellar lens, but current data provides only an upper limit on its surface brightness at die GRB position. C1 Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Garnavich, PM (reprint author), Univ Notre Dame, Dept Phys, 225 Nieuwland Sci Hall, Notre Dame, IN 46556 USA. NR 44 TC 83 Z9 84 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2000 VL 544 IS 1 BP L11 EP L15 DI 10.1086/317297 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 381GB UT WOS:000165753000003 ER PT J AU Perna, R Hernquist, L AF Perna, R Hernquist, L TI Disks irradiated by beamed radiation from compact objects SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; stars : neutron; X-rays : stars ID MAGNETIZED NEUTRON-STARS; X-RAY BINARIES; PULSARS; MODELS AB We examine the reprocessing of X-radiation from compact objects by accretion disks when the X-ray emission from the star is highly beamed. The reprocessed flux for various degrees of beaming and inclinations of the beam axis with respect to the disk is determined. We find that, in the case where the beam is produced by a nonrelativistic object, the intensity of the emitted spectrum is highly suppressed if the beam is pointing away from the disk. However, for beams produced by compact objects, general relativistic effects cause only a small reduction in the reradiated flux even for very narrow beams oriented perpendicularly to the disk. This is especially relevant in constraining models for anomalous X-ray pulsars, whose X-ray emission is highly beamed. We further discuss other factors that can influence the emission from disks around neutron stars. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Perna, R (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 26 TC 22 Z9 22 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2000 VL 544 IS 1 BP L57 EP L60 DI 10.1086/317300 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 381GB UT WOS:000165753000013 ER PT J AU Wilner, DJ Myers, PC Mardones, D Tafalla, M AF Wilner, DJ Myers, PC Mardones, D Tafalla, M TI Small-scale structure of the protostellar collapse candidate B335 imaged in CS J=5-4 emission SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : globules; ISM : individual (B335); ISM : jets and outflows; stars : formation ID BIPOLAR OUTFLOW; STAR FORMATION; LINE FORMATION; KINEMATICS; CORES; HCO+; DYNAMICS; ENVELOPE; CLOUDS; SEARCH AB We present interferometer observations of CS J = 5-4 emission in B335, an isolated round globule generally recognized from single-dish spectral line mapping to be the best candidate for a collapsing protostar. The images, with similar to2.''5 (0.003 pc) spatial resolution and 0.13 km s(-1) velocity resolution, show complex structure in the purported infall zone. The emission is dominated by a clumpy conical structure oriented in the east-west direction that we identify with a slow, dense component of the bipolar how visible on larger size scales. Comparison with the detailed predictions of the inside-out collapse model previously derived from single-dish observations show important discrepancies. The high-resolution CS J = 5-4 images show no evidence for infalling material at velocities greater than 0.5 km s(-1) coincident with the protostar that corresponds to emission in the wings of the single-dish spectrum. Instead, the emission at velocities expected for collapse is found to be associated with the outflow lobes, offset from the protostar position. Depletion may diminish the signal from infall of the densest gas. Bright clumps at blueshifted velocities within the outflow may contribute to the asymmetric appearance of optically thick lines observed with beam sizes too large to resolve these small-scale structures. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Chile, Dept Astron, Santiago, Chile. Natl Astron Observ, E-28800 Alcala De Henares, Spain. RP Wilner, DJ (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Mardones, Diego/I-5719-2016 NR 25 TC 37 Z9 37 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2000 VL 544 IS 1 BP L69 EP L73 DI 10.1086/317298 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 381GB UT WOS:000165753000016 ER PT J AU Gingerich, O AF Gingerich, O TI Plotting the pyramids SO NATURE LA English DT Editorial Material C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Gingerich, O (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 1 TC 3 Z9 3 U1 0 U2 0 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD NOV 16 PY 2000 VL 408 IS 6810 BP 297 EP 298 DI 10.1038/35042648 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 373NR UT WOS:000165296000023 PM 11099022 ER PT J AU Watters, TR Schultz, RA Robinson, MS AF Watters, TR Schultz, RA Robinson, MS TI Displacement-length relations of thrust faults associated with lobate scarps on Mercury and Mars: Comparison with terrestrial faults SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID VALLES-MARINERIS; LINKAGE; TOPOGRAPHY; MOUNTAINS; VOLCANISM; GRABENS; SHEETS AB The displacement D and length L of thrust faults associated with lobate scarps on Mercury and Mars are estimated from topographic and planimetric measurements. D ranges from 0.29 to 3.58 km for mercurian thrust faults (n = 10) and from 0.27 km to 2.90 km for martian thrust faults (n = 13). The D-L relationship between thrust fault populations analyzed on Mercury and Mars is very similar (gamma (Mercury) = 6.5 +/- 3.2 x 10(-3), gamma (Mars) = 5.9 +/- 2.0x10(-3)), and about an order of magnitude lower than terrestrial thrust faults. The difference is probably dominated by the contrast in tectonic setting between terrestrial thrust faults and those on Mercury and Mars. The similarity in morphology and the D-L relationship of the mercurian and martian thrust faults may be due to the similarity in mechanical properties of the deformed materials and the acceleration due to gravity of the two planets. C1 Smithsonian Inst, Natl Air & Space Museum, Ctr Earth & Planetary Studies, Washington, DC 20560 USA. Univ Nevada, Mackay Sch Mines, Dept Geol Sci 172, Geomech Rock Fracture Grp, Reno, NV 89557 USA. Northwestern Univ, Dept Geol Sci, Evanston, IL 60208 USA. RP Watters, TR (reprint author), Smithsonian Inst, Natl Air & Space Museum, Ctr Earth & Planetary Studies, Washington, DC 20560 USA. RI Schultz, Richard/J-4015-2015 OI Schultz, Richard/0000-0003-3198-5263 NR 31 TC 29 Z9 29 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 15 PY 2000 VL 27 IS 22 BP 3659 EP 3662 DI 10.1029/2000GL011554 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 375TW UT WOS:000165418200014 ER PT J AU Stahl, J AF Stahl, J TI Flamenco! SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Amer Art Museum, Washington, DC USA. RP Stahl, J (reprint author), Smithsonian Amer Art Museum, Washington, DC USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD NOV 15 PY 2000 VL 125 IS 19 BP 70 EP 71 PG 2 WC Information Science & Library Science SC Information Science & Library Science GA 376VL UT WOS:000165477400088 ER PT J AU Field, GB Carroll, SM AF Field, GB Carroll, SM TI Cosmological magnetic fields from primordial helicity SO PHYSICAL REVIEW D LA English DT Article ID EARLY UNIVERSE; INVERSE CASCADE; TURBULENCE; MAGNETOHYDRODYNAMICS AB Primordial magnetic fields may account for all or part of the fields observed in galaxies. We consider the evolution of the magnetic fields created by pseudoscalar effects in the early universe. Such processes can create force-free fields of maximal helicity, we show that, for such a field, magnetic energy inverse cascades to larger scales than it would have solely by flux freezing and cosmic expansion. For fields generated at the electroweak phase transition, we find that the predicted wavelength today can in principle be as large as similar to 10 kpc, and the field strength can be as large as similar to 10(-10) G. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Chicago, Dept Phys, Chicago, IL 60637 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. RP Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM gfield@cfa.harvard.edu; carroll@theory.uchicago.edu NR 28 TC 102 Z9 102 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD NOV 15 PY 2000 VL 62 IS 10 AR 103008 DI 10.1103/PhysRevD.62.103008 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 374JG UT WOS:000165341600012 ER PT J AU Forrey, RC Cote, R Dalgarno, A Jonsell, S Saenz, A Froelich, P AF Forrey, RC Cote, R Dalgarno, A Jonsell, S Saenz, A Froelich, P TI Collisions between metastable hydrogen atoms at thermal energies SO PHYSICAL REVIEW LETTERS LA English DT Article ID CROSS-SECTIONS; MOLECULES AB The complex interaction potentials arising in the approach of two metastable hydrogen 2s atoms are calculated and the cross sections for ionization, excitation transfer, and elastic scattering are predicted. The measured cross section for associative ionization at E = 4.1 meV equals 2 X 10(-15) cm(2). We calculate a total ionization cross section of 2 X 10(-13) cm(2), varying as E-2/3 at higher energies. Thus it appears that dissociative ionization is the major ionization channel. We find also that double excitation transfer into two excited H(2p) atoms is still more probable with the large cross section of 9 x 10(-12) cm(2) at E = 4.1 meV varying as E-1/2 at higher energies. The detection of the resulting Lyman alpha photons would provide a diagnostic test of our predictions. C1 Penn State Univ, Berks Lehigh Valley Coll, Reading, PA 19610 USA. Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Uppsala, Dept Quantum Chem, S-75120 Uppsala, Sweden. Max Planck Inst Quantum Opt, D-85748 Garching, Germany. RP Forrey, RC (reprint author), Penn State Univ, Berks Lehigh Valley Coll, Reading, PA 19610 USA. RI Jonsell, Svante/J-2251-2016 OI Jonsell, Svante/0000-0003-4969-1714 NR 15 TC 17 Z9 17 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 13 PY 2000 VL 85 IS 20 BP 4245 EP 4248 DI 10.1103/PhysRevLett.85.4245 PG 4 WC Physics, Multidisciplinary SC Physics GA 372RK UT WOS:000165247700013 ER PT J AU Gingerich, O AF Gingerich, O TI Henry Norris Russell - Dean of American astronomers SO NEW YORK TIMES BOOK REVIEW LA English DT Book Review C1 Harvard Univ, Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Gingerich, O (reprint author), Harvard Univ, Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU NEW YORK TIMES PI NEW YORK PA 229 W 43RD ST, NEW YORK, NY 10036-3959 USA SN 0028-7806 J9 NY TIMES BK REV JI N. Y. Times Book Rev. PD NOV 12 PY 2000 BP 39 EP 39 PG 1 WC Humanities, Multidisciplinary SC Arts & Humanities - Other Topics GA 370LW UT WOS:000165125400035 ER PT J AU Kochanek, CS White, M AF Kochanek, CS White, M TI A quantitative study of interacting dark matter in halos SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : theory; dark matter; galaxies : formation; methods : numerical ID SPHERICAL GALAXIES; GALACTIC HALOS; UNIVERSAL; CONSTRAINTS; PROFILES; MODEL AB We study the evolution of Hernquist profile "galaxies" in the presence of self-interacting dark matter (SIDM), where the properties of the dark matter can be parameterized by one number, <()over cap>(DM) = sigma M-DM(T)/a(2), for a halo of mass M-T and break radius a. While the halos form constant-density cores of size similar toa/2 on the core-radius relaxation timescale (t(rc) similar or equal to 1.7t(dyn)/<()over cap>(DM)), core collapse begins shortly thereafter, and a steeper 1/r(2) central density cusp starts forming faster than predicted by two-body relaxation. The formation of the steeper central cusp is accelerated if the cooling baryons adiabatically compress the dark matter. The natural consequence of SIDM is to exacerbate rather than to mitigate astrophysical problems created by dark matter density cusps. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Kochanek, CS (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI White, Martin/I-3880-2015 OI White, Martin/0000-0001-9912-5070 NR 44 TC 57 Z9 58 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 10 PY 2000 VL 543 IS 2 BP 514 EP 520 DI 10.1086/317149 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 378TD UT WOS:000165599300002 ER PT J AU Hradecky, V Jones, C Donnelly, RH Djorgovski, SG Gal, RR Odewahn, SC AF Hradecky, V Jones, C Donnelly, RH Djorgovski, SG Gal, RR Odewahn, SC TI Mass-to-light ratios of groups and clusters of galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; galaxies : clusters : individual (Abell 262, Abell 426, Abell; 478, Abell 1795, Abell 2052, Abell 2063; Abell 2199, MKW 4s); intergalactic medium; X-rays : galaxies ID RICH CLUSTERS; LUMINOSITY FUNCTION; ABELL CLUSTERS; DARK-MATTER; X-RAY; TEMPERATURE STRUCTURE; VIRIAL MASSES; COMA CLUSTER; OMEGA; FIELD AB We constrain the mass-to-light ratios, gas mass fractions, baryon mass fractions, and the ratios of total to luminous mass for a sample of eight nearby relaxed galaxy groups and clusters: A262, A426, A478, A1795, A2052, A2063, A2199, and MKW 4s. We use ASCA spatially resolved spectroscopic X-ray observations and ROSAT PSPC images to constrain the total and gas masses of these clusters. To measure cluster luminosities, we use galaxy catalogs resulting from the digitization and automated processing of the second generation Palomar Sky Survey plates calibrated with CCD images in the Gunn-Thuan g, r, and i bands. Under the assumption of hydrostatic equilibrium and spherical symmetry, we can measure the total masses of clusters from their intracluster gas temperature and density profiles. Spatially resolved ASCA spectra show that the gas temperature decreases with increasing distance from the center. By comparison, the assumption that the gas is isothermal results in an underestimate of the total mass at small radii and an overestimate at large cluster radii. We have obtained luminosity functions for all clusters in our sample. After correcting for background and foreground galaxies, we estimate the total cluster luminosity using Schechter function fits to the galaxy catalogs. In the three lowest redshift clusters where we can sample to fainter absolute magnitudes, we have detected a flattening of the luminosity function at intermediate magnitudes and a rise at the faint end. These clusters were fitted with a sum of two Schechter functions. The remaining clusters were well fitted with a single Schechter function. Assuming H-0 = 50 h(50) km s(-1) Mpc(-1), the measured mass-to-light ratios are similar to 100 h(50) M./L.. This, along with a high baryonic fraction, is indicative of a low-density universe with Omega0 similar to 0.15-0.2. C1 CALTECH, Pasadena, CA 91125 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. RP Hradecky, V (reprint author), CALTECH, Pasadena, CA 91125 USA. NR 65 TC 34 Z9 34 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 10 PY 2000 VL 543 IS 2 BP 521 EP 529 DI 10.1086/317158 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 378TD UT WOS:000165599300003 ER PT J AU Elvis, M Fiore, F Siemiginowska, A Bechtold, J Mathur, S McDowell, J AF Elvis, M Fiore, F Siemiginowska, A Bechtold, J Mathur, S McDowell, J TI 150 keV emission from PKS 2149-306 with BeppoSAX SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : observations; quasars : general; radiation mechanisms : nonthermal; X-rays : galaxies ID X-RAY-SPECTRA; EXTRAGALACTIC RADIO-SOURCES; ACTIVE GALACTIC NUCLEI; ENERGY-DISTRIBUTIONS; ABSORPTION FEATURE; GALAXY FORMATION; QUASARS; EVOLUTION; BLAZARS; ASCA AB A BeppoSAX observation of the z = 2.34 quasar PKS 2149 - 306 produced a strong signal in the high-energy PDS instrument up to a maximum observed energy of nearly 50 keV, 150 keV in the quasar frame. The BeppoSAX spectrum spans almost three decades (0.3-150 keV, quasar frame) and shows an extremely hard (alpha = 0.4 +/- 0.05) X-ray spectrum above 3 keV (comparable to XJB the X-ray background slope), and either a softer (alpha = 1.0(-0.3)(+0.6)) low-energy component or an ionized absorber at zero redshift. No evidence is seen of an Fe-K emission line (EW < 167 eV at 6.5 keV quasar frame), a Compton hump (R < 0.3). A bremsstrahlung fit gives kT(rest) = 46(-16)(+32) keV, similar to the X-ray background value, and a high-energy cut off power law requires E-cut > 120 keV (quasar frame). The SED of PKS 2149-306 shows two peaks at similar to 10(12+/-0.5) Hz and similar to 10(21+/-1.0) Hz (similar to0.3 mm and similar to4 MeV), strongly resembling a low-energy cut off BL Lac object (LBL). The ratio of the two peaks shows an extreme Compton dominance (C-D = 1.4 +/- 0.4), as in flat-spectrum radio quasars (FSRQs). The presence of an additional " optical/ UV big bump" component may provide photons that cool the jet, suppressing the radio emission. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Osservatorio Astron Roma, I-00040 Monte Porzio Catone, Italy. BeppoSAX Sci Data Ctr, I-00100 Rome, Italy. Steward Observ, Tucson, AZ 85724 USA. RP Elvis, M (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI Fiore, Fabrizio/0000-0002-4031-4157 NR 62 TC 12 Z9 12 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 10 PY 2000 VL 543 IS 2 BP 545 EP 551 DI 10.1086/317117 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 378TD UT WOS:000165599300006 ER PT J AU Monnier, JD Danchi, WC Hale, DS Lipman, EA Tuthill, PG Townes, CH AF Monnier, JD Danchi, WC Hale, DS Lipman, EA Tuthill, PG Townes, CH TI Mid-infrared interferometry on spectral lines. II. Continuum (dust) emission around IRC+10216 and VY canis majoris SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; instrumentation : interferometers; stars : AGB and post-AGB; stars : winds, outflows; techniques : interferometric ID CIRCUMSTELLAR ENVELOPE; EVOLVED STARS; NML CYGNI; MASS-LOSS; SHELL; TEMPERATURE; EVOLUTION; TELESCOPE; CARBON; IRC AB The University of California Berkeley Infrared Spatial Interferometer has measured the mid-infrared visibilities of the carbon star IRC +10216 and the red supergiant VY CMa. The dust shells around these sources have been previously shown to be time variable, and these new data are used to probe the evolution of the dust shells on a decade timescale, complementing contemporaneous studies at other wavelengths. Self-consistent, spherically symmetric models at maximum and minimum light both show the inner radius of the IRC +10216 dust shell to be much larger (150 mas) than expected from the dust-condensation temperature, implying that dust production has slowed or stopped in recent years. Apparently, dust does not form every pulsational cycle (638 days), and these mid-infrared results are consistent with recent near-infrared imaging, which indicates little or no new dust production in the last 3 yr. Spherically symmetric models failed to fit recent VY CMa data, implying that emission from the inner dust shell is highly asymmetric and/or time variable. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Monnier, JD (reprint author), Smithsonian Astrophys Observ, MS 42,60 Garden St, Cambridge, MA 02138 USA. RI Lipman, Everett/D-1696-2009 NR 45 TC 34 Z9 34 U1 1 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 10 PY 2000 VL 543 IS 2 BP 861 EP 867 DI 10.1086/317126 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 378TD UT WOS:000165599300030 ER PT J AU Monnier, JD Danchi, WC Hale, DS Tuthill, PG Townes, CH AF Monnier, JD Danchi, WC Hale, DS Tuthill, PG Townes, CH TI Mid-infrared interferometry on spectral lines. III. Ammonia and silane around IRC+10216 and VY canis majoris SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; instrumentation : interferometers instrumentation : spectrographs; molecular processes; stars : AGB and post-AGB; turbulence ID CIRCUMSTELLAR DUST SHELLS; LONG-PERIOD VARIABLES; IRC +10216; ENVELOPE; MOLECULES; BAND; PROFILES; SILICON; MODELS; GRAINS AB Using the University of California Berkeley Infrared Spatial Interferometer with a radio frequency (RF) filter bank, the first interferometric observations of mid-infrared molecular absorption features of ammonia (NH3) and silane (SiH4) with very high spectral resolution (lambda/Delta lambda similar to 10(5)) were made. Under the assumptions of spherical symmetry and uniform outflow, these new data permitted the molecular stratification around carbon star IRC +10216 and red supergiant VY CMa to be investigated. For IRC + 10216, both ammonia and silane were found to form in the dusty outflow significantly beyond both the dust formation and gas acceleration zones. Specifically, ammonia was found to form before silane in a region of decaying gas turbulence (greater than or equal to 20R(*)), while the silane is produced in a region of relatively smooth gas flow much farther from the star (greater than or similar to 80R(*)). The depletion of gas-phase SiS onto grains soon after dust formation may fuel silane-producing reactions on the grain surfaces. For VY CMa, a combination of interferometric and spectral observations suggest that NH3, is forming near the termination of the gas acceleration phase in a region of high gas turbulence (similar to 40R(*)). C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Monnier, JD (reprint author), Smithsonian Astrophys Observ, MS 42,60 Garden St, Cambridge, MA 02138 USA. NR 41 TC 40 Z9 40 U1 1 U2 8 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 10 PY 2000 VL 543 IS 2 BP 868 EP 879 DI 10.1086/317127 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 378TD UT WOS:000165599300031 ER PT J AU Wood, BE Karovska, M AF Wood, BE Karovska, M TI Interpreting the MgII h and k line profiles of Mira variables SO ASTROPHYSICAL JOURNAL LA English DT Article DE line : profiles; stars : AGB and post-AGB; stars : oscillations; stars : variables : other; ultraviolet : stars ID PARTIAL REDISTRIBUTION; SOLAR CHROMOSPHERE; STARS; COOL; ATMOSPHERES; ELEMENTS AB We use radiative transfer calculations to reproduce the basic appearance of Mg II lines observed from Mira variables. These lines have centroids that are blueshifted by at least 30 km s(-1) from the stellar rest frame. It is unlikely that flow velocities in the stellar atmospheres are this fast, so radiative transfer effects must be responsible for this behavior. Published hydrodynamic models predict the existence of cool downflowing material above the shocked material responsible for the Mg II emission, and we demonstrate that scattering in this layer can result in Mg II profiles as highly blueshifted as those that are observed. However, our models also show that scattering within the shock plays an equally strong role in shaping the Mg II profiles, and our calculations illustrate the importance of partial redistribution and the effects of being out of ionization equilibrium. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Univ Colorado, JILA, Boulder, CO 80309 USA. EM wood@head-cfa.harvard.edu; karovska@head-cfa.harvard.edu NR 32 TC 3 Z9 3 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD NOV 10 PY 2000 VL 543 IS 2 BP 922 EP 927 DI 10.1086/317131 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 378TD UT WOS:000165599300035 ER PT J AU Piro, L Garmire, G Garcia, M Stratta, G Costa, E Feroci, M Meszaros, P Vietri, M Bradt, H Frail, D Frontera, F Halpern, J Heise, J Hurley, K Kawai, N Kippen, RM Marshall, F Murakami, T Sokolov, VV Takeshima, T Yoshida, A AF Piro, L Garmire, G Garcia, M Stratta, G Costa, E Feroci, M Meszaros, P Vietri, M Bradt, H Frail, D Frontera, F Halpern, J Heise, J Hurley, K Kawai, N Kippen, RM Marshall, F Murakami, T Sokolov, VV Takeshima, T Yoshida, A TI Observation of X-ray lines from a gamma-ray burst (GRB991216): Evidence of moving ejecta from the progenitor SO SCIENCE LA English DT Article ID IRON LINE; AFTERGLOW; SPECTRA; EDGE AB We report on the discovery of two emission features observed in the x-ray spectrum of the afterglow of the gamma-ray burst (GRB) of 16 December 1999 by the Chandra X-ray Observatory. These features are identified with the Ly(alpha), Line and the narrow recombination continuum by hydrogenic ions of iron at a redshift z = 1.00 +/- 0.02, providing an unambiguous measurement of the distance of a GRB. Line width and intensity imply that the progenitor of the GRB was a massive star system that ejected, before the GRB event, a quantity of iron similar to0.01 of the mass of the sun at a velocity similar to0.1 of the speed of light, probably by a supernova explosion. C1 CNR, Ist Astrofis Spaziale, I-00133 Rome, Italy. Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Roma Tre, Dept Phys, I-00146 Rome, Italy. MIT, Cambridge, MA 02139 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. CNR, Ist Tecnol & Studio Radiaz Extraterr, I-40129 Bologna, Italy. Columbia Univ, Dept Astrophys, New York, NY 10027 USA. SRON, NL-3584 CA Utrecht, Netherlands. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RIKEN, Inst Phys & Chem Res, Wako, Saitama 3510198, Japan. Univ Alabama, NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35899 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. Russian Acad Sci, Special Astrophys Observ, Nizhnii Arkhyz 369167, Karachaevo Cher, Russia. NASDA, Natl Space Dev Agcy Japan, Minato Ku, Tokyo 10560, Japan. RP Piro, L (reprint author), CNR, Ist Astrofis Spaziale, Via Fosso del Cavaliere, I-00133 Rome, Italy. RI PIRO, LUIGI/E-4954-2013; Stratta, Maria Giuliana/L-3045-2016; OI PIRO, LUIGI/0000-0003-4159-3984; Stratta, Maria Giuliana/0000-0003-1055-7980; Costa, Enrico/0000-0003-4925-8523; Feroci, Marco/0000-0002-7617-3421 NR 33 TC 242 Z9 245 U1 0 U2 3 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD NOV 3 PY 2000 VL 290 IS 5493 BP 955 EP 958 DI 10.1126/science.290.5493.955 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 370BV UT WOS:000165103200040 PM 11062121 ER PT J AU Ruiz, GM Rawlings, TK Dobbs, FC Drake, LA Mullady, T Huq, A Colwell, RR AF Ruiz, GM Rawlings, TK Dobbs, FC Drake, LA Mullady, T Huq, A Colwell, RR TI Global spread of microorganisms by ships - Ballast water discharged from vessels harbours a cocktail of potential pathogens. SO NATURE LA English DT Article ID MARINE ORGANISMS; TRANSPORT; CLIMATE; DISEASE; ECOLOGY AB Ballast water discharged from vessels harbours a cocktail of potential pathogens. C1 Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. Univ Maryland, Ctr Marine Biotechnol, Inst Biotechnol, Baltimore, MD 21202 USA. Univ Maryland, Dept Cell & Mol Biol, College Pk, MD 20742 USA. Old Dominion Univ, Dept Ocean Earth & Atmospher Sci, Norfolk, VA 23529 USA. RP Ruiz, GM (reprint author), Smithsonian Environm Res Ctr, POB 28, Edgewater, MD 21037 USA. OI Ruiz, Gregory/0000-0003-2499-441X NR 14 TC 287 Z9 314 U1 3 U2 73 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD NOV 2 PY 2000 VL 408 IS 6808 BP 49 EP 50 DI 10.1038/35040695 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 369DH UT WOS:000165050400043 PM 11081499 ER PT J AU Ubelaker, DH AF Ubelaker, DH TI American Indian population recovery in the twentieth century. SO AMERICAN JOURNAL OF HUMAN BIOLOGY LA English DT Book Review C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Anthropol, Washington, DC 20560 USA. RP Ubelaker, DH (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Anthropol, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 1 U2 1 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 1042-0533 J9 AM J HUM BIOL JI Am. J. Hum. Biol. PD NOV-DEC PY 2000 VL 12 IS 6 BP 839 EP 840 DI 10.1002/1520-6300(200011/12)12:6<839::AID-AJHB12>3.0.CO;2-W PG 2 WC Anthropology; Biology SC Anthropology; Life Sciences & Biomedicine - Other Topics GA 363DZ UT WOS:000089820900012 ER PT J AU Rines, K Geller, MJ Diaferio, A Mohr, JJ Wegner, GA AF Rines, K Geller, MJ Diaferio, A Mohr, JJ Wegner, GA TI The infall region of Abell 576: Independent mass and light profiles SO ASTRONOMICAL JOURNAL LA English DT Article DE cosmology : observations; dark matter; galaxies : clusters : individual (A576); galaxies : kinematics and dynamics; galaxies : photometry ID X-RAY-CLUSTERS; GALAXY CLUSTERS; HIERARCHICAL UNIVERSE; RICH CLUSTERS; DARK-MATTER; VELOCITY DISPERSIONS; LUMINOSITY FUNCTION; DIPPER ASTERISM; REDSHIFT-SPACE; OUTER REGIONS AB We describe observations of the nearby (cz = 11,487 km s(-1)) cluster of galaxies Abell 576 beyond the virial radius and into the infall region where galaxies are on their first or second pass through the cluster. Using 1057 redshifts, we use the infall pattern in redshift space to determine the mass profile of A576 to a radius of similar to4 h(-1) Mpc. This mass estimation technique makes no assumptions about the equilibrium state of the cluster. Within similar to1 h(-1) Mpc, the mass profile we derive exceeds that determined from X-ray observations by a factor of similar to2.5. At similar to2.5 h(-1) Mpc, however, the mass profile agrees with virial mass estimates. Our mass profile is consistent with a Navarro, Frenk, & White or Hernquist profile, but it is inconsistent with an isothermal sphere. R-band images of a 3 degrees x 3 degrees region centered on the cluster allow an independent determination of the cluster light profile. We calculate the integrated mass-to-light ratio as a function of cluster radius; it decreases smoothly from the core to M/L-R similar to 300 h at similar to4 h(-1) Mpc. The differential MIL, profile decreases more steeply; we find deltaM/deltaL(R) similar to 100 h at similar to4 h(-1) Mpc, in good agreement with the mass-to-light ratios of individual galaxies. If the behavior of M/L-R in A576 is general, Omega (m) less than or similar to 0.4 at 95% confidence. For a Hernquist model, the best-fit mass profiles differ from the observed surface number density of galaxies; the galaxies have a larger scale radius than the mass. This result is consistent with the centrally peaked M/L-R profile. Similarly, the scale radius of the light profile is larger than that of the mass profile. We discuss some potential systematic effects; none can easily reconcile our results with a constant mass-to-light ratio. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Turin, Dipartimento Fis Gen Amedeo Avogadro, Turin, Italy. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Dartmouth Coll, Dept Phys & Astron, Hanover, NH 03755 USA. RP Rines, K (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM krines@cfa.harvard.edu; mgeller@cfa.harvard.edu NR 82 TC 47 Z9 47 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 EI 1538-3881 J9 ASTRON J JI Astron. J. PD NOV PY 2000 VL 120 IS 5 BP 2338 EP 2354 DI 10.1086/316811 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 369YK UT WOS:000165095200011 ER PT J AU Schlegel, EM Petre, R Colbert, EJM Miller, S AF Schlegel, EM Petre, R Colbert, EJM Miller, S TI A deep ROSAT HRI observation of NGC 1313 SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : spiral; galaxies : stellar content ID X-RAY SOURCES; SPIRAL GALAXY NGC-1313; INTERSTELLAR-MEDIUM; EMISSION; SUPERNOVA; SN-1978K AB We describe a series of observations of NGC 1313 using the ROSAT HRI with a combined exposure time of 183.5 ks. The observations span an interval between 1992 and 1998; the purpose of observations since 1994 was to monitor the X-ray flux of SN 1978K, one of several luminous sources in the galaxy. No diffuse emission is detected in the galaxy to a level of similar to1-2 x 10(37) ergs s(-1) arcmin(-2). A total of eight sources are detected in the summed image within the D(25) diameter of the galaxy. The luminosities of five of the eight range from similar to6 x 10(37) to similar to6 x 10(38) ergs s(-1); these sources are most likely accreting X-ray binaries, similar to sources observed in M31 and M33. The remaining three sources all emit above 10(39) ergs s(-1). We present light curves of the five brightest sources. Variability is detected at the 99.9% level in four of these. We identify one of the sources as an NGC 1313 counterpart of a Galactic X-ray source. The light curve, though crudely sampled, most closely resembles that of a Galactic black hole candidate such as GX 339-4 but with considerably higher peak X-ray luminosity. An additional seven sources lie outside the D(25) diameter and are either foreground stars or background active galactic nuclei. C1 Smithsonian Astrophys Observ, High Energy Astrophys Div, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Xray Astrophys Grp, Greenbelt, MD 20771 USA. Univ Maryland, Dept Agron, College Pk, MD 20742 USA. RP Schlegel, EM (reprint author), Smithsonian Astrophys Observ, High Energy Astrophys Div, Mail Stop 4,60 Garden St, Cambridge, MA 02138 USA. NR 36 TC 11 Z9 11 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD NOV PY 2000 VL 120 IS 5 BP 2373 EP 2382 DI 10.1086/316804 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 369YK UT WOS:000165095200014 ER PT J AU Sivaraman, KR Gupta, SS Livingston, WC Dame, L Kalkofen, W Keller, CU Smartt, R Hasan, SS AF Sivaraman, KR Gupta, SS Livingston, WC Dame, L Kalkofen, W Keller, CU Smartt, R Hasan, SS TI Results from a revisit to the K-2V bright points SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE Sun : chromosphere; Sun : magnetic fields ID INTRANETWORK MAGNETIC ELEMENTS; NETWORK; GRAINS; FIELDS; OSCILLATIONS; FLUX; CHROMOSPHERE; EVOLUTION; FEATURES AB We have used pairs of temporally simultaneous Call K-line spectroheliograms and magnetic area scans to search for spatial correlation between the CaII K-2V bright points in the interior of the network and corresponding magnetic elements. We find that about 60% of the K-2V bright points spatially coincide with magnetic elements of flux density > 4 Mx cm(-2). About 25% of the K-2V bright points with equally enhanced emission lie over bipole elements where the fields are > 4 Mx cm(-2) for both polarity elements which merge and presumably cancel and result in low fields. The rest, 15%, of the bright points coincide with areas of fields < 4 Mx cm(-2) which is the noise level set by us for the magnetic scans. When magnetic elements of opposite polarity merge and form bipoles, the associated K-2V bright points show excess emission. Although such excess emission is a magnetic-field-drive phenomenon, the measured value of the field at the site of the bipole is typically low and these cases would therefore be excluded in the count of coincidences of excess emission with excess magnetic fields. In our opinion, these cases of excess emission at the sites of the bipoles, as well as at the sites of fields > 4 Mx cm(-2), are both instances of magnetic field-related emissions. If the former are not taken into account as coincidences, the correlation will drop down and this might be interpreted as not an obvious correlation. Our present results, taking into account the low fields of merging bipoles, establish the association of K-2V bright points with magnetic elements. C1 CNRS, Serv Aeron, F-91371 Verrieres Buisson, France. Indian Inst Astrophys, Bangalore 560034, Karnataka, India. Natl Opt Astron Observ, Natl Solar Observ, Tucson, AZ 85726 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Natl Opt Astron Observ, Natl Solar Observ, Sunspot, NM 88349 USA. RP Dame, L (reprint author), CNRS, Serv Aeron, BP 3, F-91371 Verrieres Buisson, France. EM luc.dame@aerov.jussieu.fr RI Hasan, Siraj/C-2927-2012 NR 35 TC 22 Z9 22 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD NOV PY 2000 VL 363 IS 1 BP 279 EP 288 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 383FZ UT WOS:000165873600031 ER PT J AU Parenti, S Bromage, BJI Poletto, G Noci, G Raymond, JC Bromage, GE AF Parenti, S Bromage, BJI Poletto, G Noci, G Raymond, JC Bromage, GE TI Characteristics of solar coronal streamers - Element abundance, temperature and density from coordinated CDS and UVCSSOHO observations SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE Sun : abundances; Sun : atmosphere; Sun : corona; Sun : UV radiation ID WHOLE-SUN-MONTH; SPECTROSCOPIC DIAGNOSTICS; SOHO/CDS OBSERVATIONS; HYDROGENIC IONS; QUIET-SUN; ULTRAVIOLET; PLASMAS; RECOMBINATION; SPECTROMETER; COEFFICIENTS AB This paper presents the results from coordinated observations of streamers acquired by the SOHO Coronal Diagnostic Spectrometer (CDS) and UltraViolet Coronograph Spectrometer (UVCS) experiments. Data from different altitudes within the solar corona were taken, with the purpose of determining their physical parameters - densities, electron temperatures and element abundances - and their changes over the altitude range between 1.02 and 1.6 R.. Further UVCS streamer data, taken about two months later are used for comparison with the behaviour seen in two different streamers. Whenever possible, alternative methods have been adopted to determine the same physical parameter, as a cross check. In particular, the DEM technique has been applied to UVCS data, in order to compare abundance values derived in this way, with those obtained using the method of Raymond et al. (1997). We conclude that abundances in the low corona covered by CDS data do not show evidence for abundance variation, with respect to photospheric values, while, at UVCS altitudes, a depletion of all element abundances is clearly evident. No clear evidence of a FD? effect in streamers was found; we get contrasting results from the only two high FIP elements present in our spectra. C1 Univ Cent Lancashire, Ctr Astrophys, Preston PR1 2HE, Lancs, England. Osservatorio Astrofis Arcetri, I-50125 Florence, Italy. Univ Florence, I-50125 Florence, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Parenti, S (reprint author), Univ Cent Lancashire, Ctr Astrophys, Preston PR1 2HE, Lancs, England. EM sparenti@uclan.ac.uk NR 43 TC 65 Z9 66 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD NOV PY 2000 VL 363 IS 2 BP 800 EP 814 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 388HK UT WOS:000166174800040 ER PT J AU Matt, G Perola, GC Fiore, F Guainazzi, M Nicastro, F Piro, L AF Matt, G Perola, GC Fiore, F Guainazzi, M Nicastro, F Piro, L TI The BeppoSAX observation of Mrk 766 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : individual : Mrk 766; galaxies : Seyfert; X-rays : galaxies ID LINE SEYFERT-1 GALAXIES; ACTIVE GALACTIC NUCLEI; ASCA OBSERVATIONS; RAY; MARKARIAN-766; VARIABILITY; QUASARS; MKN-766; SPECTRA; SAMPLE AB The Narrow Line Seyfert 1 galaxy Mrk 766 has been observed by BeppoSAX on May 1997. The source was fairly variable, both in flux and spectrum, during the observation. The variability is the largest around 2 keV, possibly due to variations in the warm absorber properties. An oxygen line is clearly detected, at least in the first part of the observation. An edge around similar to7.5 keV, coupled with the lack of any detectable iron line, suggests either reprocessing of the primary X-rays by a mildly ionized disc or absorption by a further, thicker and more ionized material. C1 Univ Studi Roma Tre, Dipartimento Fis, I-00146 Rome, Italy. Osservatorio Astron Roma, I-00044 Monteporzio Catone, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. SDC Nuova Telespazio, SAX, I-00131 Rome, Italy. ESA, VILSPA, XMM SOC, Madrid 28080, Spain. CNR, Ist Astrofis Spaziale, I-00133 Rome, Italy. RP Matt, G (reprint author), Univ Studi Roma Tre, Dipartimento Fis, Via Vasca Navale 84, I-00146 Rome, Italy. RI PIRO, LUIGI/E-4954-2013; OI PIRO, LUIGI/0000-0003-4159-3984; Nicastro, Fabrizio/0000-0002-6896-1364; Fiore, Fabrizio/0000-0002-4031-4157 NR 27 TC 15 Z9 15 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD NOV PY 2000 VL 363 IS 3 BP 863 EP 868 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 388HL UT WOS:000166174900008 ER PT J AU Guelin, M Muller, S Cernicharo, J Apponi, AJ McCarthy, MC Gottlieb, CA Thaddeus, P AF Guelin, M Muller, S Cernicharo, J Apponi, AJ McCarthy, MC Gottlieb, CA Thaddeus, P TI Astronomical detection of the free radical SiCN SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE molecular data; stars : circumstellar matter; stars : AGB and post-AGB; ISM : molecules; radio lines : stars ID IRC+10216 AB We report the detection of the SiCN radical in an astronomical source, the envelope of the C star IRC +10216/CW Leo. The microwave spectrum of SiCN was recently studied by four of us in the laboratory and the rotational transition frequencies were accurately measured. The ground fine structure state, (2)Pi (1/2), has three rotational transitions, each with lambda -doubling in the 80-116 GHz atmospheric window (J = 7.5 --> 6.5, 8.5 --> 7.5 and 9.5 --> 8.5, at 83.0, 94.0, and 105.1 GHz). The three lambda -doublets (six components) are detected at a level of 5 mK with the IRAM 30-m telescope. Judging from the cusped shape of the line profiles, SiCN is largely confined to the outer molecular envelope, like most other radicals. Its abundance relative to H-2 is estimated to be 4 x 10(-9), a factor of 20 lower than that of MgNC. The isoelectronic radical SiCCH was not detected. We confirm our previous tentative detections of the carbon chain H2C6 and of NP in IRC+10216. C1 Inst Radio Astron Millimetr, F-38406 St Martin Dheres, France. Inst Estructura Mat, Madrid 28006, Spain. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Guelin, M (reprint author), Inst Radio Astron Millimetr, 300 Rue Piscine, F-38406 St Martin Dheres, France. EM guelin@iram.fr NR 13 TC 83 Z9 84 U1 1 U2 4 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD NOV PY 2000 VL 363 IS 1 BP L9 EP L12 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 383FZ UT WOS:000165873600003 ER PT J AU van den Ancker, ME Perez, MR de Winter, D McCollum, B AF van den Ancker, ME Perez, MR de Winter, D McCollum, B TI A young stellar group associated with HD 199143 (d=48 pc) SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : individual : HD 199143; stars : peculiar; stars : rotation; Galaxy : open clusters and associations : general; ultraviolet : stars ID EXTREME-ULTRAVIOLET SOURCES; ALL-SKY SURVEY; SOURCE CATALOG; STARS AB We present new optical and ultraviolet spectroscopy of the anomalous EUV emitter HD 199143 (F8V). High resolution spectra in the Her and NaID wavelength regions show evidence for very rapid (a few hundred km s(-1)) rotation of the stellar photosphere. Using archive IRAS data we also show that the star has excess emission above photospheric levels at 12 mum. IUE data of HD 199143 reveal the presence of emission lines of Mg II, C I, C Ir, C III, C IV, Si IV, He II and N V and show a large variability, both in the continuum and line fluxes. We propose that all available data of HD 199143 can be explained by assuming that is has been spun up by accretion of material from a close T Tauri like companion, responsible for the emission lines, the ultraviolet variability and the excess infrared emission. The bursting or flaring nature of this object, mostly in high energies, could be explained as episodic mass transfer between the star and its close companion. We show that HD 199143 and the Li-rich late-type dwarf BD-17 degrees 6128 form a physical pair and suggest that both may be part of a new nearby (48 pc) young (similar to 10(7) yr) stellar association in Capricornius. C1 Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Emergent IT Corp, Largo, MD 20774 USA. Inst Astrofis Canarias, Tenerife 38200, Spain. TNO, TPD, NL-2600 AD Delft, Netherlands. CALTECH, IPAC, SIRTF Sci Ctr, Pasadena, CA 91125 USA. RP Univ Amsterdam, Astron Inst Anton Pannekoek, Kruislaan 403, NL-1098 SJ Amsterdam, Netherlands. EM mario@astro.uva.nl NR 22 TC 19 Z9 19 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1432-0746 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD NOV PY 2000 VL 363 IS 2 BP L25 EP L28 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 388HK UT WOS:000166174800002 ER PT J AU Perna, R Aguirre, A AF Perna, R Aguirre, A TI Gamma-ray burst afterglows as probes of galactic and intergalactic dust SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; dust, extinction; gamma rays : bursts ID COSMOLOGICAL FIREBALL MODEL; 28 FEBRUARY 1997; X-RAY; REDSHIFT; EVOLUTION; CONSTRAINTS; ENVIRONMENT; COUNTERPART; SUPERNOVAE; EXTINCTION AB The amount and properties of high-redshift galactic and intergalactic (IG) dust are largely unknown but could be investigated using multiwavelength photometry of high-z objects that have a known intrinsic spectrum. Observations of gamma -ray burst (GRB) afterglows appear to support the theoretical model of an adiabatic blast wave expanding into an external medium. In this model the synchrotron peak flux is independent of frequency, providing a flat spectrum when observed over time, and therefore allowing straightforward measurement of the relative attenuation of afterglow flux in widely separated bands. Applying this method to dust extinction, we show that for a sample of afterglows that have been corrected by galactic extinction comparison between the number counts of peak fluxes in X-ray versus optical can provide constraints on an intergalactic component of dust. A similar technique can probe the redshift dependence of extinction in GRB-forming regions without requiring an assumed relation between extinction and reddening by the dust. Probing systematic changes in extinction with redshift, particularly in IG and/or nonreddening dust, is crucial to a proper interpretation of the Type Ia supernova Hubble diagram and similar observations and useful for understanding GRB progenitor environments. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Perna, R (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 37 TC 5 Z9 5 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 1 PY 2000 VL 543 IS 1 BP 56 EP 60 DI 10.1086/317107 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 374XB UT WOS:000165368800004 ER PT J AU Garnavich, PM Jha, S Pahre, MA Stanek, KZ Kirshner, RP Garcia, MR Szentgyorgyi, AH Tonry, JL AF Garnavich, PM Jha, S Pahre, MA Stanek, KZ Kirshner, RP Garcia, MR Szentgyorgyi, AH Tonry, JL TI RJK band observations of the optical afterglow of GRB 991216 SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; shock waves ID GAMMA-RAY BURST; 28 FEBRUARY 1997; STANDARD STARS; EMISSION AB We present near-infrared and optical observations of the afterglow to the gamma-ray burst 991216 obtained with the Fred L. Whipple Observatory 1.2 m telescope and the University of Hawaii 2.2 m telescope. The observations range from 15 hours to 3.8 days after the burst. The temporal behavior of the data is well described by a single power-law decay t(-1.36+/-0.04), independent of wavelength. The optical spectral energy distribution, which is corrected for significant Galactic reddening of E(B-V) = 0.626, is well fitted by a single power law with v(-0.58+/-0.08). Combining the IR/optical observations with a Chandra X-Ray Observatory measurement gives a spectral index of -0.8 +/- 0.1 in the synchrotron cooling regime. A comparison between the spectral and temporal power-law indices suggests that a jet is a better match to the observations than a simple spherical shock. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Garnavich, PM (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 41 TC 23 Z9 23 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 1 PY 2000 VL 543 IS 1 BP 61 EP 65 DI 10.1086/317102 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 374XB UT WOS:000165368800005 ER PT J AU Kochanek, CS Falco, EE Impey, CD Lehar, J McLeod, BA Rix, HW Keeton, CR Munoz, JA Peng, CY AF Kochanek, CS Falco, EE Impey, CD Lehar, J McLeod, BA Rix, HW Keeton, CR Munoz, JA Peng, CY TI The fundamental plane of gravitational lens galaxies and the evolution of early-type galaxies in low-density environments SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : evolution; galaxies : photometry; gravitational lensing ID COLOR-MAGNITUDE RELATION; FIELD ELLIPTIC GALAXIES; COMA CLUSTER; COSMOLOGICAL CONSTANT; VELOCITY DISPERSIONS; SPHERICAL GALAXIES; DISTANT CLUSTERS; MERGER MODEL; S0 GALAXIES; REDSHIFT AB Most gravitational lenses are early-type galaxies in relatively low density environments-a "field" rather than a "cluster" population. Their average properties are the mass-averaged properties of all early-type galaxies. We show that held early-type galaxies with 0 < z < 1, as represented by the lens galaxies, lie on the same fundamental plane as those in rich clusters at similar redshifts. We then use the fundamental plane to measure the combined evolutionary and K-corrections for early-type galaxies in the V, I, and H bands. Only for passively evolving stellar populations formed at z(f) greater than or similar to 2 (H-0 = 65 km s(-1) Mpc(-1), Omega (0), = 0.3, lambda (0) = 0.7) can the lens galaxies be matched to the local fundamental plane. The high formation epoch and the lack of significant differences between the held and cluster populations contradict many current models of the formation history of early-type galaxies. Lens galaxy colors and the fundamental plane provide good photometric redshift estimates with an empirical accuracy of [z(FP) - z(l)]= -0.04 +/- 0.09 for the 20 lenses with known redshifts. A mass model dominated by dark matter is more consistent with the data than either an isotropic or radially anisotropic constant MIL mass model, and a radially anisotropic model is better than an isotropic model. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Max Planck Inst Astron, D-69117 Heidelberg, Germany. RP Kochanek, CS (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 89 TC 144 Z9 144 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 1 PY 2000 VL 543 IS 1 BP 131 EP 148 DI 10.1086/317074 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 374XB UT WOS:000165368800012 ER PT J AU Tuthill, PG Monnier, JD Danchi, WC Lopez, B AF Tuthill, PG Monnier, JD Danchi, WC Lopez, B TI Smoke signals from IRC+10216. I. Milliarcsecond proper motions of the dust SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; infrared : stars; ISM : jets and outflows; stars : AGB and post-AGB; stars : individual (IRC 10216); stars : mass loss ID CIRCUMSTELLAR ENVELOPE; PLANETARY-NEBULA; PINWHEEL NEBULA; AGB STARS; SHELLS; IRC; SPECTRA; GRAINS AB The results of a seven epoch interferometric imaging study, at wavelengths in the near-infrared K band, of the carbon star IRC+10216 are presented. The use of non- and partially redundant aperture masking techniques on the 10 m Keck I telescope has allowed us to produce images of the innermost regions of the circumstellar dust envelope with unprecedented detail, With roughly twice the resolving power of previous work, the complex asymmetric structures reported within the central 0".5 (similar to 20 R-*) have been imaged at the size scale of the stellar disk itself (similar to 50 mas). A prominent dark lane at a position angle of approximately 120 degrees is suggested to be an optically thick disk or torus of dust which could help to explain IRC+10216's well-known bipolarity at a position angle of similar to 20 degrees. Observations spanning more than a pulsational cycle (similar to 638 days) have revealed significant temporal evolution of the nebula, including the outward motion of bright knots and clumps. Registering these displacements against the compact bright core, which we tentatively identify as marking the location of the star, has allowed us to determine the apparent angular velocity at a number of points. The magnitudes of the proper motions were found to be in agreement with current estimates of the stellar distance and radial velocity. Higher outflow speeds were found for features with greater separation from the core. This is consistent with acceleration taking place over the region sampled by the measurements; however, alternate interpretations are also presented. Although a number of changes of morphology were found, none were clearly interpreted as the condensation of new dust over the pulsation cycle. Unfortunately, ambiguities associated with the true three-dimensional nature of the nebula weaken a number of our quantitative and qualitative conclusions. C1 Univ Sydney, Sch Phys, Chatterton Astron Dept, Sydney, NSW 2006, Australia. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. Observ Cote Azur, Dept Fresnel, UMR 6528, F-06034 Nice 4, France. RP Tuthill, PG (reprint author), Univ Sydney, Sch Phys, Chatterton Astron Dept, Sydney, NSW 2006, Australia. NR 27 TC 68 Z9 68 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 1 PY 2000 VL 543 IS 1 BP 284 EP 290 DI 10.1086/317082 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 374XB UT WOS:000165368800026 ER PT J AU Martin, EL Brandner, W Bouvier, J Luhman, KL Stauffer, J Basri, G Osorio, MRZ Navascues, DBY AF Martin, EL Brandner, W Bouvier, J Luhman, KL Stauffer, J Basri, G Osorio, MRZ Navascues, DBY TI Membership and multiplicity among very low mass stars and brown dwarfs in the Pleiades cluster SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : general; open clusters and associations : individual (Pleiades); stars : evolution; stars : formation; stars : low mass, brown dwarfs; stars : luminosity function, mass function ID EXTRASOLAR GIANT PLANETS; SOLAR-TYPE STARS; BINARY; CANDIDATES; LITHIUM; SEARCH; SPECTROMETER; ATMOSPHERES; METALLICITY; DISCOVERY AB We present near-infrared photometry and optical spectroscopy of very low mass stars and brown dwarf candidates in the Pleiades open cluster. The membership status of these objects is assessed using color-magnitude diagrams, lithium and spectral types. Eight objects out of 45 appear to be nonmembers. A search for companions among 34 very low mass Pleiades members (M less than or equal to 0.09 M-.) in high spatial resolution images obtained with the Hubble Space Telescope (HST) and the adaptive optics system of the Canada-France-Hawaii telescope produced no resolved binaries with separations larger than 0."2 (a similar to 27 AU; P similar to 444 yr). Nevertheless, we find evidence for a binary sequence in the color-magnitude diagrams, in agreement with the results of Steele & Jameson for higher mass stars. We apply the lithium test to two objects: CFHT-P1-16, which lies in the cluster binary sequence but is unresolved in images obtained with the Hubble Space Telescope; and CFHT-P1-18, which is binary with 0."33 separation. The first object passes the test, but the second object does not. We conclude that CFHT-Pl-16 is an Pleiades brown dwarf binary with separation less than 11 AU and that CFHT-Pl-18 is a foreground system. We compare the multiplicity statistics of the Pleiades very low mass stars and brown dwarfs with that of G-and K-type main-sequence stars in the solar neighborhood. We find that there is some evidence for a deficiency of wide binary systems (separation >27 AU) among the Pleiades very low mass members. We briefly discuss how this result can fit with current scenarios of brown dwarf formation. We correct the Pleiades substellar mass function for the contamination of cluster nonmembers found in this work. We find a contamination level of 33% among the brown dwarf candidates identified by Bouvier et al. Assuming a power-law IMF across the substellar boundary, we find a slope dN/dM similar to M-0.53, implying that the number of objects per mass bin is still rising but the contribution to the total mass of the cluster is declining in the brown dwarf regime. C1 Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Observ Grenoble, F-38041 Grenoble 9, France. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Inst Astrofis Canarias, E-38200 La Laguna, Tenerife, Spain. Univ Autonoma Madrid, Dept Fis Teor, E-28049 Madrid, Spain. RP Martin, EL (reprint author), CALTECH, Div Geol & Planetary Sci, 150-21, Pasadena, CA 91125 USA. RI Barrado Navascues, David/C-1439-2017; Zapatero Osorio, Maria Rosa/C-2744-2017 OI Barrado Navascues, David/0000-0002-5971-9242; Zapatero Osorio, Maria Rosa/0000-0001-5664-2852 NR 55 TC 121 Z9 121 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 1 PY 2000 VL 543 IS 1 BP 299 EP 312 DI 10.1086/317089 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 374XB UT WOS:000165368800028 ER PT J AU Chatterjee, P Hernquist, L AF Chatterjee, P Hernquist, L TI The spin period, luminosity, and age distributions of anomalous X-ray pulsars SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; pulsars : general; stars : neutron; X-rays : stars ID RX J0720.4-3125; MAGNETIC-FIELD; NEUTRON-STARS; EVOLUTION AB We consider the accretion model for anomalous X-ray pulsars proposed recently by Chatterjee, Hernquist, and Narayan, in which the emission is powered by accretion from a fossil disk that is formed by the fallback of material from a supernova explosion. We demonstrate that this model is able to account for the spin period, luminosity, and age distributions of the observed population of anomalous X-ray pulsars (AXPs) for reasonable and broad distributions of the free parameters of the model, namely, the surface magnetic field of the neutron star, the mass of its accretion disk, and its initial spin period. In particular, this model is able statistically to account for the puzzlingly narrow observed spin distribution of the AXPs. We show also that if the establishment of fallback accretion disks around isolated neutron stars is a universal phenomenon, then a fairly large minority (similar to 20%) of these objects become X-ray-bright AXPs or X-ray-faint systems spinning down by propeller action, while the rest become radio pulsars. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Chatterjee, P (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 25 TC 29 Z9 32 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 1 PY 2000 VL 543 IS 1 BP 368 EP 372 DI 10.1086/317097 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 374XB UT WOS:000165368800036 ER PT J AU Bersier, D AF Bersier, D TI The distance to the Fornax dwarf galaxy using red clump stars and the discrepancy between red clump and tip of the red giant branch distances SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : distances and redshifts; galaxies : individual (Carina, Fornax, Large Magellanic Cloud); stars : late-type ID GRAVITATIONAL LENSING EXPERIMENT; LARGE-MAGELLANIC-CLOUD; MAGNITUDE; METALLICITY; SCALE; MAPS AB I determine a distance to the Fornax dwarf galaxy using stars in the red clump and at the tip of the red giant branch. They are in very good agreement, with mu (0) = 20.66 mag. Comparing the magnitudes of the tip of the red giant branch and of the red clump in Fornax, Carina, and the Magellanic Clouds, I propose a possible solution to the problem of the discrepancy between these two types of distance measurements. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Bersier, D (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 27 TC 23 Z9 23 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 1 PY 2000 VL 543 IS 1 BP L23 EP L26 DI 10.1086/318170 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 374XD UT WOS:000165369000006 ER PT J AU Morton, ES Derrickson, KC Stutchbury, BJM AF Morton, ES Derrickson, KC Stutchbury, BJM TI Territory switching behavior in a sedentary tropical passerine, the dusky antbird (Cercomacra tyrannina) SO BEHAVIORAL ECOLOGY LA English DT Article DE Aves (birds); removal experiments; RHP; territory switching; mate switching; mate choice; genetic monogamy; Cercomacra tyrannina; tropical passerine; antbird ID REMOVAL EXPERIMENTS; BIRDS; PANAMA; POPULATIONS; HYPOTHESIS; FLOATERS; INSECTS; FLOCKS AB Demographic data from an 8-year study of a marked population showed that switching territories and mates is common in both genders of dusky antbirds (Cercomacra tyrannina), a sedentary neotropical passerine with year-round territories and pairbonds. We conducted 22 experimental removals and followed six natural disappearances to examine territory switching. Antbirds quickly abandoned territories and mates to move to openings created by experimental removals. Pairing with the resident on a new territory was rapid. Unmated birds attracted new mates by singing a gender-specific song that differed from songs given by mated birds. There were no gender differences in replacement time or rate. Some vacancies, experimental and natural, were not filled, suggesting that floaters were rare. Territory and mate switching were not related to immediate enhancement of reproductive success because the probability of reproducing successfully was equally poor on all territories. Territory switching may be an overlooked but common tropical form of territoriality that increases individual survivorship during periods of low food abundance (dry season). We suggest that switching is favored when low annual reproductive success enhances selection for a long lifespan as the primary means to increase reproductive success. C1 Natl Zool Pk, Conservt & Res Ctr, Front Royal, VA 22630 USA. Loyola Coll, Dept Biol, Baltimore, MD 21210 USA. York Univ, Dept Biol, N York, ON M3J 1P3, Canada. RP Morton, ES (reprint author), Natl Zool Pk, Conservt & Res Ctr, 1500 Remount Rd, Front Royal, VA 22630 USA. RI Piper, Walter/B-7908-2009 NR 38 TC 45 Z9 47 U1 4 U2 17 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 1045-2249 J9 BEHAV ECOL JI Behav. Ecol. PD NOV-DEC PY 2000 VL 11 IS 6 BP 648 EP 653 DI 10.1093/beheco/11.6.648 PG 6 WC Behavioral Sciences; Biology; Ecology; Zoology SC Behavioral Sciences; Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Zoology GA 383HX UT WOS:000165878000010 ER PT J AU Weldon, PJ Gorra, MF Wood, WF AF Weldon, PJ Gorra, MF Wood, WF TI Short-chain carboxylic acids from the anal glands of the binturong, Arctictis binturong (Viverridae, Mammalia) SO BIOCHEMICAL SYSTEMATICS AND ECOLOGY LA English DT Article DE Arctictis binturony; binturong; Viverridae; anal glands; carboxylic acids C1 Humboldt State Univ, Dept Chem, Arcata, CA 95521 USA. Smithsonian Inst, Conservat & Res Ctr, Front Royal, VA 22630 USA. Carnivore Preservat Trust, Pittsboro, NC 27312 USA. RP Wood, WF (reprint author), Humboldt State Univ, Dept Chem, Arcata, CA 95521 USA. OI Wood, William/0000-0002-2991-0054 NR 4 TC 1 Z9 1 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0305-1978 J9 BIOCHEM SYST ECOL JI Biochem. Syst. Ecol. PD NOV PY 2000 VL 28 IS 9 BP 903 EP 904 DI 10.1016/S0305-1978(99)00128-3 PG 2 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 351QQ UT WOS:000089170000009 ER PT J AU Herberstein, ME Craig, CL Coddington, JA Elgar, MA AF Herberstein, ME Craig, CL Coddington, JA Elgar, MA TI The functional significance of silk decorations of orb-web spiders: a critical review of the empirical evidence SO BIOLOGICAL REVIEWS LA English DT Review DE Arancidae; Uloboridae; Tetragnathidae; Stabilimenta; Araneae; behaviour; phylogeny ID ARGIOPE-KEYSERLINGI KARSCH; SPINNING SPIDERS; FORAGING STRATEGIES; BUILDING SPIDERS; ARANEAE; ARANEIDAE; PREY; STABILIMENTUM; BEHAVIOR; EVOLUTION AB A number of taxonomically diverse species of araneoid spiders adorn their orb-webs with conspicuous silk structures, called decorations or stabilimenta. The function of these decorations remains controversial and several explanations have been suggested, These include: (1) stabilising and strengthening the web; (2) hiding and concealing the spider from predators; (3) preventing web damage by larger animals, such as birds; (4) increasing foraging success; or (5) providing a sunshield. Additionally, they may have no specific function and are a consequence of stress or silk regulation. This review evaluates the strength of these explanations based on the evidence. The foraging function has received most supporting evidence, derived from both correlative field studies and experimental manipulations. This contrasts with the evidence provided for other functional explanations, which have not yet been tested as extensively. A phylogenetic analysis of the difficult decoration patterns suggests that the different types of decorations are as evolutionary labile as the decorations themselves: the analysis shows little homology and numerous convergences and independent gains. Therefore, it is possible that different types of decorations have different functions: and this can only be resolved by improved species phylogenics, and a combination of experimental and ultimately comparative analyses. C1 Univ Melbourne, Dept Zool, Melbourne, Vic 3010, Australia. Harvard Univ, Museum Comparat Zool, Cambridge, MA 02138 USA. Tufts Univ, Ctr Biotechnol, Medford, MA 02155 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Entomol, Washington, DC 20560 USA. RP Herberstein, ME (reprint author), Univ Melbourne, Dept Zool, Melbourne, Vic 3010, Australia. RI Herberstein, Marie/D-2042-2011; OI Herberstein, Marie/0000-0001-5071-2952; Elgar, Mark/0000-0003-0861-6064 NR 90 TC 101 Z9 106 U1 2 U2 28 PU CAMBRIDGE UNIV PRESS PI PORT CHESTER PA 110 MIDLAND AVE, PORT CHESTER, NY 10573-4930 USA SN 1464-7931 J9 BIOL REV JI Biol. Rev. PD NOV PY 2000 VL 75 IS 4 BP 649 EP 669 PG 21 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 410RQ UT WOS:000167453300005 PM 11117202 ER PT J AU Romano, SL Cairns, SD AF Romano, SL Cairns, SD TI Molecular phylogenetic hypotheses for the evolution of scleractinian corals SO BULLETIN OF MARINE SCIENCE LA English DT Article ID DEPENDENT PERMUTATION TEST; GENUS ACROPORA; ENVIRONMENTAL VARIATION; MAXIMUM-LIKELIHOOD; SEQUENCE VARIATION; MITOCHONDRIAL-DNA; CNIDARIA; FOSSIL; RELIABILITY; ORIGINS AB The evolutionary history of scleractinian corals is based on knowledge of skeletal characters and their 250 million yr fossil record. However, homologies of skeletal characters are not well-understood and fossil documentation of these characters is incomplete. As a result, relationships among families and suborders are poorly understood. We have analyzed a 225 bp segment of the nuclear 288 ribosomal RNA gene from 45 species of corals and a 566 bp segment of the mitochondrial 16S ribosomal RNA gene from 68 species. Unlike previous analyses of smaller numbers of taxa, the dataset presented here includes both reef-building and non-reef-building taxa from 20 of 24 families and all seven suborders. Nuclear sequences analyzed under maximum parsimony and minimum evolution criteria did not resolve relationships among families and suborders. Similar analyses of mitochondrial sequences resulted in a robust phylogenetic hypothesis. The mitochondrial hypothesis, like previous analyses of a subset of these data, did not agree with morphological hypotheses about relationships among families and suborders, and supports a polyphyletic origin of the scleractinian skeleton. Instead of seven major monophyletic groups as hypothesized from morphological data, mitochondrial data suggest that the Scleractinia is represented by two major clades. Relationships within these major clades are not clearly differentiated but each clade is comprised of families from different morphological suborders as defined by Veron (1995). The mitochondrial topology gives no support for the morphological suborders Archaeocoeniina, Fungiina, Caryophylliina, or Meandriina as monophyletic groups but is consistent with a monophyletic Faviina, Poritiina, and Dendrophylliina. Monophyletic morphological families are supported with the exception of the Faviiidae, Caryophylliidae, Poritidae, and Oculinidae. The mitochondrial topology also supports the most recent taxonomic treatments of Psammocora and Fungiacyathus, genera that have been the subject of taxonomic debate. C1 Smithsonian Inst, Natl Museum Nat Hist, Lab Mol Systemat, Washington, DC 20560 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. RP Romano, SL (reprint author), Univ Virgin Isl, Div Sci & Math, 2 John Brewers Bay, St Thomas, VI 00802 USA. NR 94 TC 114 Z9 121 U1 0 U2 15 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD NOV PY 2000 VL 67 IS 3 BP 1043 EP 1068 PG 26 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 381FD UT WOS:000165750900013 ER PT J AU DePriest, PT Ivanova, NV Fahselt, D Alstrup, V Gargas, A AF DePriest, PT Ivanova, NV Fahselt, D Alstrup, V Gargas, A TI Sequences of psychrophilic fungi amplified from glacier-preserved ascolichens SO CANADIAN JOURNAL OF BOTANY-REVUE CANADIENNE DE BOTANIQUE LA English DT Article DE ancient DNA; small subunit ribosomal DNA; 18S ribosomal DNA; phylogenetic analysis; psychrophilic fungi; lichen-forming fungi ID SSU RDNA PHYLOGENY; DNA-SEQUENCES; LICHENS; FAMILY; ICE AB Ribosomal DNA sequences were amplified from subfossils of the ascolichen Umbilicaria cylindrica (L.) Delise ex Duby collected at the ablating edges of Greenland glaciers. Surprisingly, phylogenetic analysis indicated that the amplified rDNA sequences were not closely related to those of the lichen-forming fungus but rather represented two groups of psychrophilic basidiomycetes (orders Cystofilobasidiales and Sporidiales) and one group of ascomycetes (order Leotiales). Two of these groups, the Sporidiales and the Leotiales, include other fungi previously detected in DNA extracted from the grass clothing of the Tyrolean Iceman desiccated and frozen for over 3000 years and also in 2000- and 4000-year-old ice core samples from northern Greenland. Large subunit ribosomal DNA sequences representing the group Cystofilobasidiales were nearly identical to those of the basidioyeast saprobe Mrakia frigida. The adjacent internal transcribed spacer sequence was more than 98% similar to those from three samples of U. cylindrica from different sites that had been subjected to ice burial for various lengths of time, suggesting they also were Mrakia sequences. Although ancient contamination of multiple U. cylindrica specimens with fungi such as Mrakia cannot be ruled out, it is more probable that saprobic colonization of the subfossil tissues by psychrophilic fungi proceeded during recent ice melt. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, Washington, DC 20560 USA. Moscow MV Lomonosov State Univ, Belozersky Inst Physicochem Biol, Dept Evolutionary Biochem, Plant Genosystemat Lab, Moscow 117234, Russia. Univ Western Ontario, Dept Plant Sci, London, ON N6A 5B7, Canada. Univ Dar Es Salaam, Dept Bot, Dar Es Salaam, Tanzania. Univ Wisconsin, Dept Bot, Madison, WI 53706 USA. RP DePriest, PT (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, NHB-166, Washington, DC 20560 USA. RI DePriest, Paula/K-6633-2015 NR 36 TC 15 Z9 15 U1 0 U2 2 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0008-4026 J9 CAN J BOT JI Can. J. Bot.-Rev. Can. Bot. PD NOV PY 2000 VL 78 IS 11 BP 1450 EP 1459 PG 10 WC Plant Sciences SC Plant Sciences GA 385KX UT WOS:000166004300008 ER PT J AU Flint, OS AF Flint, OS TI A new species of Anisocentropus (Trichoptera : Calamoceratidae) from Sri Lanka SO ENTOMOLOGICAL NEWS LA English DT Article AB Anisocentropus atropurpureus from the island of Sri Lanka is described and the male genitalia figured. It is closely related to A. annulicornis differing primarily in its purplish-black wings and orange body, and lowland distribution. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Entomol, Washington, DC 20560 USA. RP Flint, OS (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Entomol, Washington, DC 20560 USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU AMER ENTOMOL SOC PI PHILADELPHIA PA 1900 BENJ FRANKLIN PARKWAY, PHILADELPHIA, PA 19103-1195 USA SN 0013-872X J9 ENTOMOL NEWS JI Entomol. News PD NOV-DEC PY 2000 VL 111 IS 5 BP 337 EP 340 PG 4 WC Entomology SC Entomology GA 392AV UT WOS:000166389200006 ER PT J AU Chance, K Palmer, PI Spurr, RJD Martin, RV Kurosu, TP Jacob, DJ AF Chance, K Palmer, PI Spurr, RJD Martin, RV Kurosu, TP Jacob, DJ TI Satellite observations of formaldehyde over North America from GOME SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CHEMISTRY; OZONE AB Formaldehyde (HCHO) is an important indicator of tropospheric hydrocarbon emissions and photochemical activity. We present HCHO observations over North America for July 1996 from the GOME instrument on-board the ESA ERS-2 satellite. Slant columns are determined to <4x10(15) molecules cm(-2) sensitivity by directly fitting GOME radiance measurements. These show a distinct enhancement over the southeastern United States, consistent with a large regional source from oxidation of non-methane hydrocarbons including in particular isoprene. Conversion of slant to vertical columns is done by combining species vertical distribution information from the GEOS-CHEM 3-D tropospheric chemistry and transport model with scattering weights from the Smithsonian Astrophysical Observatory LIDORT multiple scattering radiative transfer model. The results demonstrate the ability to measure HCHO from space in typical continental atmospheres, and imply that space-based measurements of HCHO may provide valuable information on emission fluxes of reactive hydrocarbons. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Harvard Univ, Div Appl Sci, Cambridge, MA 02138 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. RP Chance, K (reprint author), 60 Garden St, Cambridge, MA 02138 USA. EM kchance@cfa.harvard.edu; pip@io.harvard.edu; rspurr@cfa.harvard.edu; rvm@io.harvard.edu; tkurosu@cfa.harvard.edu; djj@io.harvard.edu RI Martin, Randall/A-2051-2008; Palmer, Paul/F-7008-2010; Martin, Randall/C-1205-2014; Chem, GEOS/C-5595-2014; OI Martin, Randall/0000-0003-2632-8402; Chance, Kelly/0000-0002-7339-7577 NR 23 TC 136 Z9 137 U1 3 U2 17 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 1 PY 2000 VL 27 IS 21 BP 3461 EP 3464 DI 10.1029/2000GL011857 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 369JW UT WOS:000165063000007 ER PT J AU McCoy, TJ Nittler, LR Burbine, TH Trombka, JI Clark, PE Murphy, ME AF McCoy, TJ Nittler, LR Burbine, TH Trombka, JI Clark, PE Murphy, ME TI Anatomy of a partially differentiated asteroid: A "NEAR"-sighted view of acapulcoites and lodranites SO ICARUS LA English DT Article; Proceedings Paper CT 7th International Asteroids, Comets, Meteors Conference (ACM 99) CY JUL 26-30, 1999 CL CORNELL UNIV, ITHACA, NY HO CORNELL UNIV DE asteroids; asteroids, Eros; asteroids, composition; meteorites; NEAR mission ID ORDINARY CHONDRITES; IRON-METEORITES; PARENT BODY; DIFFUSION AB With the insertion of the NEAR spacecraft into orbit around the asteroid 433 Eros, a new stage of asteroid exploration has begun, with the return of spatially resolved mineralogical, geological, and chemical information from specific asteroids. In this paper, we outline the features of a partially differentiated asteroid using the acapulcoite and lodranite meteorites as a guide. Such a body would likely contain a variety of lithologies, including chondritic rocks largely unaltered by melting, residues of partial melts, and basaltic and Fe,Ni-FeS rocks crystallized from the partial melts. The presence or nature of the regolith remains largely unconstrained, Mineralogical and isotopic heterogeneities preserved in these rocks suggest spatial separation of these rock types by distances in excess of 200 m. Spacecraft-based remote sensing instrumentation should detect substantial spectral heterogeneity (most prominently manifested in the band area ratio) and chemical heterogeneity. Observation of these various lithologies in situ would provide important new constraints on the processes involved during the earliest differentiation of asteroids. C1 Smithsonian Inst, Dept Mineral Sci, Museum Natl Hist Nat, Washington, DC 20560 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP McCoy, TJ (reprint author), Smithsonian Inst, Dept Mineral Sci, Museum Natl Hist Nat, Washington, DC 20560 USA. NR 30 TC 17 Z9 17 U1 0 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD NOV PY 2000 VL 148 IS 1 BP 29 EP 36 DI 10.1006/icar.2000.6494 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 375UV UT WOS:000165420400005 ER PT J AU Qiu, YL Lee, J Bernasconi-Quadroni, F Soltis, DE Soltis, PS Zanis, M Zimmer, EA Chen, Z Savolainen, V Chase, MW AF Qiu, YL Lee, J Bernasconi-Quadroni, F Soltis, DE Soltis, PS Zanis, M Zimmer, EA Chen, Z Savolainen, V Chase, MW TI Phylogeny of basal angiosperms: Analyses of five genes from three genomes SO INTERNATIONAL JOURNAL OF PLANT SCIENCES LA English DT Article; Proceedings Paper CT 16th International Botanical Congress CY AUG 03-06, 1999 CL ST LOUIS, MISSOURI SP Amer Bryolog & Lichenolog Soc DE basal angiosperms; Amborella; ANITA; eumagnoliids; euangiosperms; gymnosperms; phylogeny; multigene analysis ID RIBOSOMAL DNA-SEQUENCES; INFERRING COMPLEX PHYLOGENIES; EASTERN NORTH-AMERICA; SEED PLANT PHYLOGENY; FLOWERING PLANTS; DATA SETS; NUCLEOTIDE-SEQUENCES; DOUBLE FERTILIZATION; 18S RDNA; REPRODUCTIVE STRUCTURES AB DNA sequences of five mitochondrial, plastid, and nuclear genes from 105 species (103 genera and 63 families) representing all major lineages of gymnosperms and basal angiosperms were analyzed using parsimony methods to reconstruct the phylogeny of basal angiosperms. The standard most parsimonious trees search, taxon deletion analyses, and constraint analyses in combination with Kishino-Hasegawa tests provided a rigorous analytical perspective for identifying Amborella, Nymphaeales, and Illiciales-Trimeniaceae-Austrobaileya (ANITA) as the basalmost lineages of extant angiosperms. The parsimony criterion (equal weighting) favored the trees in which Amborella was sister to all other angiosperms, whereas the likelihood measure favored the trees in which the Amborella-Nymphaeales clade represented the first diverging lineage of angiosperms. However, the Kishino-Hasegawa test showed that these trees, as well as those in which Nymphaeales were sister to all other angiosperms, were not significantly different from each other. The clade of eumagnoliids, consisting of Winterales, Piperales, Magnoliales, and Laurales, was also consistently recovered in all of the analyses, albeit with low bootstrap support. Two genera of Gnetales, Gnetum and Welwitschia, did not form a sister group to angiosperms but fell into conifers with strong support. This result refutes the anthophyte hypothesis. C1 Univ Zurich, Inst Systemat Bot, CH-8008 Zurich, Switzerland. Univ Massachusetts, Dept Biol, Amherst, MA 01003 USA. Washington State Univ, Sch Biol Sci, Pullman, WA 99164 USA. Smithsonian Inst, Lab Mol Systemat, Washington, DC 20560 USA. Chinese Acad Sci, Inst Bot, Lab Systemat & Evolutionary Bot, Beijing 100093, Peoples R China. Royal Bot Gardens, Richmond TW9 3DS, Surrey, England. RP Qiu, YL (reprint author), Univ Zurich, Inst Systemat Bot, Zollikerstr 107, CH-8008 Zurich, Switzerland. RI Chase, Mark /A-6642-2011; Zimmer, Elizabeth/G-3890-2011; Soltis, Pamela/L-5184-2015 NR 171 TC 143 Z9 156 U1 1 U2 13 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 1058-5893 J9 INT J PLANT SCI JI Int. J. Plant Sci. PD NOV PY 2000 VL 161 IS 6 SU S BP S3 EP S27 DI 10.1086/317584 PG 25 WC Plant Sciences SC Plant Sciences GA 380FX UT WOS:000165690500002 ER PT J AU Zimmer, EA Qiu, YL Endress, PK Friis, EM AF Zimmer, EA Qiu, YL Endress, PK Friis, EM TI Current perspectives on basal angiosperms: Introduction SO INTERNATIONAL JOURNAL OF PLANT SCIENCES LA English DT Editorial Material ID GENES C1 Smithsonian Inst, Natl Museum Nat Hist, Lab Mol Syst, Washington, DC 20560 USA. Univ Zurich, Inst Systemat Bot, CH-8008 Zurich, Switzerland. Univ Massachusetts, Dept Biol, Amherst, MA 01003 USA. Swedish Museum Nat Hist, Dept Palaeobot, S-10405 Stockholm, Sweden. RP Zimmer, EA (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Lab Mol Syst, Washington, DC 20560 USA. RI Zimmer, Elizabeth/G-3890-2011 NR 10 TC 3 Z9 6 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 1058-5893 J9 INT J PLANT SCI JI Int. J. Plant Sci. PD NOV PY 2000 VL 161 IS 6 SU S BP S1 EP S2 DI 10.1086/317569 PG 2 WC Plant Sciences SC Plant Sciences GA 380FX UT WOS:000165690500001 ER PT J AU Sadeghpour, HR AF Sadeghpour, HR TI Channel interaction in alkali-halide photodissociation: Interferometric lineshapes and dynamic switching SO INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY LA English DT Article; Proceedings Paper CT 40th Annual Sanibel Symposium CY FEB 26-MAR 03, 2000 CL ST AUGUSTINE, FLORIDA SP IBM Corp, HyperCube Inc, Univ Florida DE photodissociation; channel interaction; quantum defect theory; wavepacket dispersion; coherent interference ID QUANTUM DEFECT THEORY; CHARGE-TRANSFER; STATES; PREDISSOCIATION; SPECTROSCOPY; DISSOCIATION; EXCITATION; EVOLUTION; PULSE; LIF AB Photodissociation of alkali-halides is studied using a hybrid close-coupling and multichannel quantum defect theory approach. A novel class of interferometry that arises from the coherent interference of alternative pathways to bond breaking is identified. Interferometric resonances that live for hundreds of picoseconds are analyzed in the spirit of channel interaction. interfering patterns that form in Me interaction zone due to collision of nuclear wavepackets are revealed. (C) 2000 John Wiley & Sons, Inc. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. RP Sadeghpour, HR (reprint author), Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, 60 Garden St, Cambridge, MA 02138 USA. NR 26 TC 1 Z9 1 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0020-7608 J9 INT J QUANTUM CHEM JI Int. J. Quantum Chem. PD NOV-DEC PY 2000 VL 80 IS 4-5 BP 958 EP 965 DI 10.1002/1097-461X(2000)80:4/5<958::AID-QUA45>3.3.CO;2-X PG 8 WC Chemistry, Physical; Mathematics, Interdisciplinary Applications; Physics, Atomic, Molecular & Chemical SC Chemistry; Mathematics; Physics GA 370DP UT WOS:000165108300044 ER PT J AU Thomas, MA AF Thomas, MA TI Redefining library space: Managing the coexistence of books, computers, and readers SO JOURNAL OF ACADEMIC LIBRARIANSHIP LA English DT Article AB Library design must better integrate space for collections and computers than it has. This article presents planning strategies that integrate digital products and print collections based on patron needs. Many flexible solutions in developing buildings will enhance library service in the technologically dynamic future. C1 Smithsonian Inst, Management & Tech Serv, Washington, DC 20560 USA. RP Thomas, MA (reprint author), Smithsonian Inst, Management & Tech Serv, NHB 22, Washington, DC 20560 USA. NR 9 TC 12 Z9 12 U1 0 U2 3 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0099-1333 J9 J ACAD LIBR JI J. Acad. Librariansh. PD NOV PY 2000 VL 26 IS 6 BP 408 EP 415 DI 10.1016/S0099-1333(00)00161-0 PG 8 WC Information Science & Library Science SC Information Science & Library Science GA 385QT UT WOS:000166015700006 ER PT J AU Kraft, C Jenett-Siems, K Siems, K Gupta, MP Bienzle, U Eich, E AF Kraft, C Jenett-Siems, K Siems, K Gupta, MP Bienzle, U Eich, E TI Antiplasmodial activity of isoflavones from Andira inermis SO JOURNAL OF ETHNOPHARMACOLOGY LA English DT Article; Proceedings Paper CT Joint Meeting on 2000 Years of Natural Product Research - Past, Present and Future CY JUL 26-30, 1999 CL AMSTERDAM, NETHERLANDS SP Amer Soc Pharmacognosy, Assoc Francaise Enseignement & Rech Pharmacognosy, Gesell Arzneipflanzenforsch, Phytochem Soc Europe DE Andira inermis; fabaceae; isoflavones; calycosin; genistein; antiplasmodial activity; Plasmodium falciparum ID MEDICINAL-PLANTS; INDIANS; INVENTORY; CULTURE AB The stem bark and seeds of Andira inermis, Fabaceae, are employed as a purgative, vermifuge, and febrifuge. In particular, the powdered bark is claimed to be efficacious in intermittent fever. Bioassay-guided fractionation of lipophilic extracts from the stems and leaves yielded six isoflavones: biochanin A, calycosin, formononetin, genistein, pratensein, and prunetin. Calycosin (3',7-dihydroxy-4'-methoxyisoflavone) and genistein (4',5,7-trihydroxyisoflavone) have been shown to possess in vitro activity against the chloroquine-sensitive strain poW and the chloroquine-resistant clone Dd2 of Plasmodium falciparum. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved. C1 Free Univ Berlin, Inst Pharm Pharmazeut Biol, D-14195 Berlin, Germany. AnalytCon AG, Potsdam, Germany. Univ Panama, Fac Farm, Ctr Invest Farmacognost Flora Panamena, CIFLORPAN, Panama City, Panama. Smithsonian Trop Res Inst, Panama City, Panama. Humboldt Univ, Med Fak Charite, Inst Trop Med, Berlin, Germany. RP Jenett-Siems, K (reprint author), Free Univ Berlin, Inst Pharm Pharmazeut Biol, Konigin Luise Str 2-4, D-14195 Berlin, Germany. OI Gupta, Mahabir/0000-0002-9302-7864 NR 17 TC 37 Z9 40 U1 0 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0378-8741 J9 J ETHNOPHARMACOL JI J. Ethnopharmacol. PD NOV PY 2000 VL 73 IS 1-2 BP 131 EP 135 DI 10.1016/S0378-8741(00)00285-3 PG 5 WC Plant Sciences; Chemistry, Medicinal; Integrative & Complementary Medicine; Pharmacology & Pharmacy SC Plant Sciences; Pharmacology & Pharmacy; Integrative & Complementary Medicine GA 365PD UT WOS:000089958900015 PM 11025148 ER PT J AU Kharchenko, V Dalgarno, A Zygelman, B Yee, JH AF Kharchenko, V Dalgarno, A Zygelman, B Yee, JH TI Energy transfer in collisions of oxygen atoms in the terrestrial atmosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID FAST NITROGEN-ATOMS; HOT OXYGEN; O(P-3) ATOMS; O(D-1) ATOMS; SOLAR-CYCLE; MARS; THERMALIZATION; GEOCORONA; VENUS; PRECIPITATION AB The total and differential cross sections of elastic O(P-3) + O(P-3) collisions have been obtained from quantal calculations, and the rate of energy relaxation of fast oxygen atoms in atmospheric oxygen gas has been evaluated using realistic differential cross sections of oxygen-oxygen collisions. All the electronic energy curves of O-2 separating to the atomic ground states have been incorporated in calculations of the scattering phase shifts. The total and differential cross sections averaged over a statistical population of O(P-3) fine structure levels have been used for calculations of the self-diffusion coefficient, the viscosity and thermal conductivity of oxygen gas. The kernel of the Boltzmann equation for the energy relaxation process has been determined. The rate of energy losses of energetic oxygen atoms in the upper terrestrial atmosphere are calculated for typical thermospheric conditions. The energy distribution function of the recoil oxygen atoms is constructed using the computed energy relaxation kernel. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA. RP Kharchenko, V (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 33 TC 43 Z9 46 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD NOV 1 PY 2000 VL 105 IS A11 BP 24899 EP 24906 DI 10.1029/2000JA000085 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 369YX UT WOS:000165096300002 ER PT J AU Ellis, SL Bowen, WD Boness, DJ Iverson, SJ AF Ellis, SL Bowen, WD Boness, DJ Iverson, SJ TI Maternal effects on offspring mass and stage of development at birth in the harbor seal, Phoca vitulina SO JOURNAL OF MAMMALOGY LA English DT Article DE birth date; birth mass; harbor seal; maternal age; maternal mass; Phoca vitulina ID ANTARCTIC FUR SEALS; SOUTHERN ELEPHANT SEALS; LIFE-HISTORY CONSEQUENCES; DEER CERVUS-ELAPHUS; FETAL GROWTH; RED DEER; REPRODUCTIVE SUCCESS; HALICHOERUS-GRYPUS; MIROUNGA-LEONINA; GREY SEAL AB We studied effects of maternal age, body mass, and parturition date on birth mass and stage of development at birth in harbor seals (Phoca vitulina) on Sable Island, Nova Scotia, over a 10-year period, As predicted, effects of maternal mass and age on pup traits varied with maternal age. Premature pups, characterized by extensive fetal pelage termed lanugo, weighed 20% less than newborns without lanugo and were born early in the season to low-body-mass females 4-6 years of age, Among intermediate-age females (7-10 years old), percentage of lanugo on pups was correlated negatively with female postpartum body mass but not with female age. Thus, maternal condition rather than age had stronger effects on stage of development of offspring at birth. Overall, maternal age explained 54% of the variance in birth mass, whereas postpartum mass of females explained only 20% of the variance. These relationships did not differ with sex of the pup, although male pups were 3.7% heavier than female pups. Effects of maternal age were strongest among young females; however; reproductive parity was more important than age itself in determining offspring birth mass. C1 Fisheries & Oceans Canada, Bedford Inst Oceanog, Marine Fish Div, Dartmouth, NS B2Y 4A2, Canada. Dalhousie Univ, Dept Biol, Halifax, NS B3H 4J1, Canada. Smithsonian Inst, Natl Zool Pk, Dept Zool Res, Washington, DC 20008 USA. RP Bowen, WD (reprint author), Fisheries & Oceans Canada, Bedford Inst Oceanog, Marine Fish Div, POB 1006, Dartmouth, NS B2Y 4A2, Canada. RI Bowen, William/D-2758-2012 NR 60 TC 25 Z9 25 U1 2 U2 16 PU AMER SOC MAMMALOGISTS PI PROVO PA BRIGHAM YOUNG UNIV, DEPT OF ZOOLOGY, PROVO, UT 84602 USA SN 0022-2372 J9 J MAMMAL JI J. Mammal. PD NOV PY 2000 VL 81 IS 4 BP 1143 EP 1156 DI 10.1644/1545-1542(2000)081<1143:MEOOMA>2.0.CO;2 PG 14 WC Zoology SC Zoology GA 379JA UT WOS:000165637900023 ER PT J AU Thorington, RW Darrow, K AF Thorington, RW Darrow, K TI Anatomy of the squirrel wrist: Bones, ligaments, and muscles SO JOURNAL OF MORPHOLOGY LA English DT Article ID FLYING SQUIRRELS; SCIURIDAE; RODENTIA; MYOLOGY; GENERA AB Anatomical differences among squirrels are usually most evident in the comparison of flying squirrels and nongliding squirrels. This is true of wrist anatomy, probably reflecting the specializations of flying squirrels for the extension of the wing tip and control of it during gliding. In the proximal row of carpals of most squirrels, the pisiform articulates only with the triquetrum, but in flying squirrels there is also a prominent articulation between the pisiform and the scapholunate, providing a more stable base for the styliform cartilage, which supports the wing tip. In the proximal wrist joint, between these carpals and the radius and ulna, differences in curvature of articular surfaces and in the location of ligaments also correlate with differences in degree and kind of movement occurring at this joint, principally reflecting the extreme dorsal flexion and radial deviation of the wrist in flying squirrels when gliding. The distal wrist joint, between the proximal. and distal rows of carpals, also shows most variation among flying squirrels, principally in the articulations of the centrale with the other carpal bones, probably causing the distal row of carpal bones to function more like a single unit in some animals. There is little variation in wrist musculature, suggesting only minor evolutionary modification since the tribal radiation of squirrels, probably in the early Oligocene. Variation in the carpal bones, particularly the articulation of the pisiform with the triquetrum and the scapholunate, suggests a different suprageneric grouping of flying squirrels than previously proposed by McKenna (1962) and Mein (1970). J. Morphol. 246:85-102, 2000. (dagger)Published 2000 Wiley-Liss, Inc. C1 Smithsonian Inst, Dept Vertebrate Zool, Washington, DC 20560 USA. RP Thorington, RW (reprint author), Smithsonian Inst, Dept Vertebrate Zool, NHB 390,MRC 108, Washington, DC 20560 USA. EM Thorington.Richard@NMNH.SI.EDU NR 35 TC 24 Z9 24 U1 1 U2 8 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0362-2525 J9 J MORPHOL JI J. Morphol. PD NOV PY 2000 VL 246 IS 2 BP 85 EP 102 DI 10.1002/1097-4687(200011)246:2<85::AID-JMOR4>3.0.CO;2-5 PG 18 WC Anatomy & Morphology SC Anatomy & Morphology GA 370PR UT WOS:000165131900004 PM 11074577 ER PT J AU Meisner, AD Burns, JR Weitzman, SH Malabarba, LR AF Meisner, AD Burns, JR Weitzman, SH Malabarba, LR TI Morphology and histology of the male reproductive system in two species of internally inseminating South American catfishes, Trachelyopterus lucenai and T-galeatus (Teleostei : Auchenipteridae) SO JOURNAL OF MORPHOLOGY LA English DT Article DE testis; seminal vesicle; Auchenipteridae; spermatozeugmata ID PHYLOGENETIC ANALYSIS; PHALLOSTETHID FISHES; GAMETIC ASSOCIATION; TESTIS; PISCES; FERTILIZATION; HEMIRAMPHIDAE; CHARACIDAE; HALFBEAKS; GENERA AB As part of an effort to characterize reproductive modifications in internally inseminating catfishes, ovaries and male reproductive systems were examined histologically in two species of auchenipterid catfishes, Trachelyopterus lucenai and T. galeatus, from southeastern Brazil. Internal insemination was documented in both species by the presence of sperm within ovaries. Although there is some variation in gross morphology of the male reproductive systems between the two species, both have four main regions: spermatogenic lobes, sperm storage regions, and secretory and storage regions of the seminal vesicle. In both species, the anterior portion of the reproductive system is spermatogenic and divided into numerous finger-like lobes. Posterior to the spermatogenic area is the storage region of the seminal vesicle, a large median structure with a honeycomb-like appearance. This region is consistently larger in T. lucenai. Attached to the storage region of the seminal vesicle in both species are secretory lobes comprised of tubules lined by secretory cells. These lobes in T. lucenai are small and located on the anterior aspect of the storage region of the seminal vesicle, whereas in T. galeatus the lobes are much larger and located laterally. The sperm storage regions of T. lucenai consist of two large lobes located ventral to the storage region of the seminal vesicle. Highly compact sperm packets (spermatozeugmata) fill the lumina of the ramifying tubules of these regions. Each spermatozeugma consists of elongate nuclei tightly arranged parallel to one another. In T. galeatus two distinct sperm storage regions are present. Just posterior to the spermatogenic lobes a series of small lobes serve as anterior sperm storage regions. Posterior to the secretory lobes of the seminal vesicle is a series of lobes, at the most posterior aspect of the reproductive tract, that serve as posterior sperm storage regions. Both are identical, histologically, to the sperm storage regions of T. lucenai. An absence of compact spermatozeugmata in the T. galeatus specimens may be related to variations in their sexual activity. The descriptions presented here allow for consistent terminology for comparison of regions of the male reproductive system based on presumed function. J. Morphol. 246:131-141, 2000. (C) 2000 Wiley-Liss, Inc. C1 Amer Museum Nat Hist, Dept Ichthyol, New York, NY 10024 USA. George Washington Univ, Dept Biol Sci, Washington, DC 20052 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Vertebrate Zool, MRC 159, Washington, DC USA. Univ Fed Rio Grande do Sul, Dept Zool, Porto Alegre, RS, Brazil. Pontificia Univ Catolica Rio Grande do Sul, Museu Ciencias & Tecnol, Porto Alegre, RS, Brazil. RP Meisner, AD (reprint author), Amer Museum Nat Hist, Dept Ichthyol, New York, NY 10024 USA. EM meisner@amnh.org RI Malabarba, Luiz/I-3225-2012 NR 50 TC 33 Z9 37 U1 0 U2 2 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0362-2525 J9 J MORPHOL JI J. Morphol. PD NOV PY 2000 VL 246 IS 2 BP 131 EP 141 DI 10.1002/1097-4687(200011)246:2<131::AID-JMOR7>3.0.CO;2-K PG 11 WC Anatomy & Morphology SC Anatomy & Morphology GA 370PR UT WOS:000165131900007 ER PT J AU Kensley, B Schotte, M AF Kensley, B Schotte, M TI New species and records of anthuridean isopod crustaceans from the Indian Ocean SO JOURNAL OF NATURAL HISTORY LA English DT Article DE Crustacea; Isopoda; Anthuridea; Antheluridae; Anthuridae; Hyssuridae; Paranthuridae; Indian Ocean AB Twenty four new species of anthuridean isopods are described from a variety of localities in the Indian Ocean, including the granitic Seychelles, Aldabra Atoll, Phuket Island, the Persian Gulf and Zanzibar Island: Family Antheluridae, Anthomuda quadrilineata; Family Anthuridae, Amakusanthura cosmoledo, Apanthuroides aldabrae, Apanthuroides calculosa, Eisothistos andamanensis, Eisothistos corallina, Heptanthura phuket, Malacanthura arabica, Mesanthura quadrata, Panathura indica, Pendanthura picardi, Pendanthura seminigra, Pendanthura siamensis, Quantanthura andamanensis; Family Hyssuridae, Neohyssura gladia, Xenanthura victoriae; Family Paranthuridae, Accalathura hastata, Accalathura phuketensis, Accalathura wardae, Leptanthura calcis, Leptanthura maheensis, Paranthura algophila, Paranthura seychellensis, Paranthura urodentata. Of the 15 genera represented, all except two were previously known from the Indian Ocean; Heptanthura and Pendanthura are recorded from the Indian Ocean for the first time. Most of the genera have wide distributions through the Indian, Atlantic and Pacific oceans, while the species tend to be endemic to limited island or coastal regions. The 15 genera are diagnosed and keys or comparative tables to the Indian Ocean species are provided. C1 Smithsonian Inst, Museum Natl Hist Nat, Dept Invertebrate Zool, Washington, DC 20560 USA. RP Kensley, B (reprint author), Smithsonian Inst, Museum Natl Hist Nat, Dept Invertebrate Zool, Washington, DC 20560 USA. NR 63 TC 6 Z9 6 U1 2 U2 3 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0022-2933 EI 1464-5262 J9 J NAT HIST JI J. Nat. Hist. PD NOV PY 2000 VL 34 IS 11 BP 2057 EP 2121 DI 10.1080/002229300750022358 PG 65 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 374CC UT WOS:000165326000003 ER PT J AU Russell, BC AF Russell, BC TI Review of the southern temperate fish family Aplodactylidae (Pisces : Perciformes) SO JOURNAL OF NATURAL HISTORY LA English DT Review DE Aplodactylidae; fish; taxonomy; Australia; New Zealand; south-west Pacific; Peru; Chile ID NEW-ZEALAND; SYSTEM; CHILE AB The southern temperate perciform fish family Aplodactylidae is reviewed. The monotypic genus Crinodus is relegated to the synonymy of the genus Aplodactylus, which is recognized as containing five species: A. arctidens Richardson from New Zealand and Australia (Victoria, South Australia and Tasmania); A. lophodon (Gunther) restricted to south-eastern Australia (New South Wales and Victoria); A. westralis Russell restricted to south Western Australia; A. etheridgii (Ogilby) from the south-west Pacific (north-eastern New Zealand, Kermadec Islands, Lord Howe Island and Norfolk Island); and A. punctatus Valenciennes from the west coast of South America (Peru and Chile). A key to the species is given. C1 Museum & Art Gallery No Terr, Darwin, NT 0801, Australia. Smithsonian Inst, Museum Natl Hist Nat, Washington, DC 20560 USA. RP Russell, BC (reprint author), Museum & Art Gallery No Terr, POB 4646, Darwin, NT 0801, Australia. NR 54 TC 2 Z9 4 U1 1 U2 9 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0022-2933 J9 J NAT HIST JI J. Nat. Hist. PD NOV PY 2000 VL 34 IS 11 BP 2157 EP 2171 DI 10.1080/002229300750022385 PG 15 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 374CC UT WOS:000165326000006 ER PT J AU Quiroz-Barroso, SA Pojeta, J Sour-Tovar, F Morales-Soto, S AF Quiroz-Barroso, SA Pojeta, J Sour-Tovar, F Morales-Soto, S TI Pseudomulceodens: A Mississippian rostroconch from Mexico SO JOURNAL OF PALEONTOLOGY LA English DT Article C1 Univ Nacl Autonoma Mexico, Fac Ciencias, Museo Paleontol, Mexico City 04510, DF, Mexico. Smithsonian Inst, Museum Nat Hist, US Geol Survey, Washington, DC 20560 USA. Univ Autonoma Guerrero, Escuela Reg Ciencias Tierra, Taxco Viejo 40280, Guerrero, Mexico. RP Quiroz-Barroso, SA (reprint author), Univ Nacl Autonoma Mexico, Fac Ciencias, Museo Paleontol, Ciudad Univ, Mexico City 04510, DF, Mexico. OI Sour-Tovar, Francisco/0000-0002-8864-6329 NR 15 TC 7 Z9 8 U1 0 U2 1 PU PALEONTOLOGICAL SOC INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 USA SN 0022-3360 J9 J PALEONTOL JI J. Paleontol. PD NOV PY 2000 VL 74 IS 6 BP 1184 EP 1186 DI 10.1666/0022-3360(2000)074<1184:PAMRFM>2.0.CO;2 PG 3 WC Paleontology SC Paleontology GA 387YW UT WOS:000166151500017 ER PT J AU Li, AS Stoecker, DK Coats, DW AF Li, AS Stoecker, DK Coats, DW TI Spatial and temporal aspects of Gyrodinium galatheanum in Chesapeake Bay: distribution and mixotrophy SO JOURNAL OF PLANKTON RESEARCH LA English DT Article ID DINOFLAGELLATE GYMNODINIUM-GALATHEANUM; MARIAE-LEBOURIAE DINOPHYCEAE; HARMFUL ALGAL BLOOMS; PROROCENTRUM-MINIMUM; PHYTOPLANKTON; GROWTH; RESPONSES; LIGHT; TRANSPORT; ORGANISM AB Gyrodinium galatheanum (Braarud) Taylor 1995 is a common bloom-forming, potentially toxic photosynthetic dinoflagellate in Chesapeake Bay, USA. Abundance of this dinoflagellate achieved densities >4 x 10(3) cells ml(-1) in the mid- and upper Bay during late spring and early summer of 1995 and 1996. Ingestion of cryptophytes by this dinoflagellate was detected in most samples collected from the Bay. During late spring and early summer, mean number of ingested cryptophytes per G.galatheanum was as high as 0.46 for dinoflagellate populations located in surface waters of the mid- and upper Bay where dissolved inorganic phosphorus was low. Observations on the distribution of G.galatheanum in Chesapeake Bay show that populations of this dinoflagellate were usually restricted to waters with salinities ranging from 7 to 18 psu, seasonally progressed up the estuary, and usually co-occurred with cryptophytes. Correlation analysis indicates that abundance of G.galatheanum and incidence of feeding was negatively correlated with dissolved inorganic phosphorus, and that incidence of feeding was positively correlated with abundance of cryptophyte prey. These results indicate that G.galatheanum is an important component of the Chesapeake Bay phytoplankton during the spring and summer. Our results suggest that the phagotrophic capability possessed by this phototrophic dinoflagellate may contribute to its success in a varying-resource environment like Chesapeake Bay. C1 Univ Maryland, Horn Point Environm Lab, Ctr Environm Sci, Cambridge, MD 21613 USA. Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. RP Li, AS (reprint author), Woods Hole Oceanog Inst, Dept Biol, Woods Hole, MA 02543 USA. RI stoecker, diane/F-9341-2013 NR 39 TC 46 Z9 50 U1 3 U2 11 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0142-7873 J9 J PLANKTON RES JI J. Plankton Res. PD NOV PY 2000 VL 22 IS 11 BP 2105 EP 2124 DI 10.1093/plankt/22.11.2105 PG 20 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 377WN UT WOS:000165549400006 ER PT J AU Schmidt, G Zotz, G AF Schmidt, G Zotz, G TI Herbivory in the epiphyte, Vriesea sanguinolenta Cogn. & Marchal (Bromeliaceae) SO JOURNAL OF TROPICAL ECOLOGY LA English DT Article DE Bromeliaceae; epiphytes; herbivory; Panama; Riodinidae ID PROTECTION; MEXICO; ORCHID; ANTS AB Although herbivory in ground-rooted flora is well documented, current knowledge of the herbivore pressure on vascular epiphytes remains mostly anecdotal. Here, we present the results of a 3-year study on the herbivory in a population of the epiphytic bromeliad Vriesea sanguinolenta. In different years, 26-61% of all epiphytes showed traces of herbivore attack, while up to 4.4% of the entire leaf area of the epiphyte population was consumed annually. The recorded levels of damage to photosynthetic tissue, mostly caused by the larvae of Napaea eucharilla (Riodinidae, Lepidoptera), indicate that vascular epiphytes may be regularly and sometimes even lethally attacked by insect herbivores. The level of damage is comparable to ground-rooted tropical flora, which certainly does not support the prevalent notion of low and negligible levels of herbivory in vascular epiphytes. C1 Univ Wurzburg, Lehrstuhl Bot 2, D-97082 Wurzburg, Germany. Smithsonian Trop Res Inst, Balboa, Panama. RP Schmidt, G (reprint author), Univ Wurzburg, Lehrstuhl Bot 2, Julius Von Sachs Pl 3, D-97082 Wurzburg, Germany. NR 34 TC 17 Z9 18 U1 0 U2 5 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0266-4674 J9 J TROP ECOL JI J. Trop. Ecol. PD NOV PY 2000 VL 16 BP 829 EP 839 DI 10.1017/S0266467400001747 PN 6 PG 11 WC Ecology SC Environmental Sciences & Ecology GA 393YV UT WOS:000166498000003 ER PT J AU Kalfatovic, MR AF Kalfatovic, MR TI Landscape with figures: A history of art dealing in the United States. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst Libs, Washington, DC 20560 USA. RP Kalfatovic, MR (reprint author), Smithsonian Inst Libs, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD NOV 1 PY 2000 VL 125 IS 18 BP 78 EP 78 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA 372MX UT WOS:000165238400047 ER PT J AU Riley, S AF Riley, S TI Last refuge of scoundrels. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst Lib, Washington, DC USA. RP Riley, S (reprint author), Smithsonian Inst Lib, Washington, DC USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD NOV 1 PY 2000 VL 125 IS 18 BP 135 EP 136 PG 2 WC Information Science & Library Science SC Information Science & Library Science GA 372MX UT WOS:000165238400283 ER PT J AU Budel, B Meyer, A Salazar, N Zellner, H Zotz, G Lange, OL AF Budel, B Meyer, A Salazar, N Zellner, H Zotz, G Lange, OL TI Macrolichens of montane rain forests in Panama, Province Chiriqui SO LICHENOLOGIST LA English DT Article ID WATER RELATIONS; CO2 EXCHANGE; LICHENS AB Sixty-eight lichen species were found in the lower montane rain forest of Fortune (1000-1200 m) in the province of Chiriqui, Panama; 33 of these were cyanobacterial lichens. The montane rain forest of the Volcan Bani (2200-3100 m) yielded 30 species of lichens, 13 of which have cyanobacterial photobionts. Forty of the species reported are new records for Panama. Information concerning their habitats within the forest and their phyrogeographical affinities is provided where possible. (C) 2000 The British Lichen Society. C1 Univ Kaiserslautern, Fachbereich Biol, D-67653 Kaiserslautern, Germany. Univ Wurzburg, Julius von Sachs Inst Biowissensch, D-97082 Wurzburg, Germany. Smithsonian Trop Res Inst, Panama City, Panama. RP Budel, B (reprint author), Univ Kaiserslautern, Fachbereich Biol, POB 3049, D-67653 Kaiserslautern, Germany. NR 25 TC 11 Z9 16 U1 0 U2 1 PU CAMBRIDGE UNIV PRESS PI CAMBRIDGE PA EDINBURGH BLDG, SHAFTESBURY RD, CB2 8RU CAMBRIDGE, ENGLAND SN 0024-2829 J9 LICHENOLOGIST JI Lichenologist PD NOV PY 2000 VL 32 BP 539 EP 551 DI 10.1006/lich.2000.0295 PN 6 PG 13 WC Plant Sciences; Mycology SC Plant Sciences; Mycology GA 377GA UT WOS:000165503900004 ER PT J AU McConnaughey, TA Adey, WH Small, AM AF McConnaughey, TA Adey, WH Small, AM TI Community and environmental influences on reef coral calcification SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID SYSTEM AB Reef corals calcify faster in the presence of noncalcareous algae. Ratios of calcification to photosynthesis appear to be affected by the ratio of alkalinity to acidity, which controls how efficiently the protons from calcification convert bicarbonate to carbon dioxide. By forcing calcifiers to calcify faster, algal proliferation on nutrient-enriched reefs may adversely affect the reef-builders. C1 Natl Museum Nat Hist, Smithsonian Inst, Washington, DC 20560 USA. RP McConnaughey, TA (reprint author), 1304 Cedar Lane, Selah, WA 98942 USA. NR 15 TC 30 Z9 32 U1 0 U2 9 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD NOV PY 2000 VL 45 IS 7 BP 1667 EP 1671 PG 5 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 373AW UT WOS:000165267100020 ER PT J AU Thiel, M AF Thiel, M TI Population and reproductive biology of two sibling amphipod species from ascidians and sponges SO MARINE BIOLOGY LA English DT Article ID EXTENDED PARENTAL CARE; PREDATORY REEF FISH; HALICHONDRIA-PANICEA; PARACERCEIS-SCULPTA; CLEANING SYMBIOSIS; CARIBBEAN SPONGES; MALE MORPHS; HOST-USE; SHRIMP; FAUNA AB The population dynamics and reproductive biology of an ascidian- and a sponge-dwelling amphipod were examined. The two undescribed amphipod species, Leucothoe "ascidicola" and L. "spongicola", are closely related to each other, and occur in ascidians and sponges, respectively, along the Florida Atlantic coast. L. "ascidicola" was abundant in solitary ascidians during fall 1997, disappeared during spring/early summer, and became abundant again in September 1998. During the time when L. "ascidicola" were absent from their hosts, a copepod became a frequent inhabitant of the ascidians but disappeared again when L. "ascidicola" returned to the ascidians in September 1998. The numbers of L. "spongicola" in sponges increased substantially during spring, when high reproductive activity was observed. Following this reproductive peak, both adult and juvenile amphipods apparently left the sponges, and during the summer amphipod numbers in the sponges were very low. Another small amphipod species, which often co-occurred with L. "spongicola", showed less seasonal variation and was found in sponges throughout the whole study period. The percentage of ovigerous females per host unit was usually lower in the ascidian-dwelling than in the sponge-dwelling amphipods. In solitary ascidians, L. "ascidicola" amphipods usually occurred in groups of several adults, yet there never was more than one ovigerous female per ascidian. In contrast, several ovigerous L. "spongicola" females were found to cohabit in the same spongocoel. This suggests that intrasexual aggression may be stronger among reproductive amphipod females in the ascidians than in sponges. The size distributions of juvenile cohorts indicate that juvenile L. "ascidicola" remain for relatively long time periods in the parental ascidian, where they may reach sexual maturity. In contrast, in L. "spongicola", only cohorts of very small juveniles could be identified, indicating that juveniles disperse shortly after emerging from the female's brood pouch. It is concluded that extended parental care is of very short duration or does not occur in the sponge-dwelling amphipod L. "spongicola", possibly because fast-growing sponges with a highly branched spongocoel system do not allow long-lasting coexistence of parent-offspring groups. In contrast, the discrete character of the solitary ascidians may enhance the potential for exclusion of other species, resource monopolization by reproductive females, and furthermore for long-lasting extended parental care in the ascidian-dwelling amphipod. Groups of single parents together with cohorts of large juveniles are reported in the literature for amphipods and isopods from brachiopods, bivalves and ascidians, suggesting that these discrete biotic microhabitats may favor the evolution of extended parental care in peracarid crustaceans. C1 Smithsonian Marine Stn, Ft Pierce, FL 34946 USA. RP Thiel, M (reprint author), Univ Catolica Norte, Fac Ciencias Mar, Llarondo 1281,Campus Guayacan, Coquimbo, Chile. NR 91 TC 31 Z9 34 U1 0 U2 5 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0025-3162 J9 MAR BIOL JI Mar. Biol. PD NOV PY 2000 VL 137 IS 4 BP 661 EP 674 DI 10.1007/s002270000372 PG 14 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 376CJ UT WOS:000165440400012 ER PT J AU Benedix, GK McCoy, TJ Keil, K Love, SG AF Benedix, GK McCoy, TJ Keil, K Love, SG TI A petrologic study of the IAB iron meteorites: Constraints on the formation of the IAB-Winonaite parent body SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID SILICATE-BEARING INCLUSIONS; ORDINARY CHONDRITES; ASTEROIDS; ORIGIN; IIICD; MINERALOGY; DIFFERENTIATION; CLASSIFICATION; FRAGMENTATION; METAMORPHISM AB We studied 26 IAB iron meteorites containing silicate-bearing inclusions to better constrain the many diverse hypotheses for the formation of this complex group. These meteorites contain inclusions that fall broadly into five types: (1) sulfide-rich, composed primarily of troilite and containing abundant embedded silicates; (2) nonchondritic, silicate-rich, comprised of basaltic, troctolitic, and peridotitic mineralogies; (3) angular, chondritic silicate-rich, the most common type, with approximately chondritic mineralogy and most closely resembling the winonaites in composition and texture; (4) rounded, often graphite-rich assemblages that sometimes contain silicates; and (5) phosphate-bearing inclusions with phosphates generally found in contact with the metallic host. Similarities in mineralogy and mineral and O-isotopic compositions suggest that IAB iron and winonaite meteorites are from the same parent body. We propose a hypothesis for the origin of IAB iron meteorites that combines some aspects of previous formation models for these meteorites. We suggest that the precursor parent body was chondritic, although unlike any known chondrite group. Metamorphism, partial melting,and incomplete differentiation (i.e., incomplete separation of melt from residue) produced metallic, sulfide-rich and silicate partial melts (portions of which may have crystallized prior to the mixing event), as well as metamorphosed chondritic materials and residues. Catastrophic impact breakup and reassembly of the debris while near the peak temperature mixed materials from various depths into the re-accreted parent body. Thus, molten metal from depth was mixed with near-surface silicate rock, resulting in the formation of silicate-rich IAB iron and winonaite meteorites. Results of smoothed particle hydrodynamic model calculations support the feasibility of such a mixing mechanism. Not all of the metal melt bodies were mixed with silicate materials during this impact and reaccretion event, and these are now represented by silicate-free IAB iron meteorites. Ages of silicate inclusions and winonaites of 4.40-4.54 Ga indicate this entire process occurred early in solar system history. C1 Arizona State Univ, Dept Geol, Tempe, AZ 85287 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Mineral Sci, Washington, DC 20560 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Hawaii Manoa, Sch Ocean & Earth Sci & Technol, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. Hawaii Ctr Volcanol, Honolulu, HI USA. RP Benedix, GK (reprint author), Virginia Tech, Dept Geol Sci, Blacksburg, VA 24061 USA. OI Benedix, Gretchen/0000-0003-0990-8878 NR 66 TC 96 Z9 99 U1 0 U2 4 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD NOV PY 2000 VL 35 IS 6 BP 1127 EP 1141 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 385LF UT WOS:000166005400001 ER PT J AU Krot, AN Meibom, A Petaev, MI Keil, K Zolensky, ME Saito, A Mukai, M Ohsumi, K AF Krot, AN Meibom, A Petaev, MI Keil, K Zolensky, ME Saito, A Mukai, M Ohsumi, K TI Ferrous silicate spherules with euhedral iron-nickel metal grains from CH carbonaceous chondrites: Evidence for supercooling and condensation under oxidizing conditions SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID PORPHYRITIC PYROXENE CHONDRULES; FEO-RICH; MODEL; PETROLOGY; ALH85085; CRYSTALLIZATION; SYSTEMS; POOR; CR AB The CH carbonaceous chondrites contain a population of ferrous (Fe/(Fe + Mg) approximate to 0.1-0.4) silicate spherules (chondrules), about 15-30 mum in apparent diameter, composed of cryptocrystalline olivine-pyroxene normative material, +/-SiO2-rich glass, and rounded-to-euhedral Fe,Ni metal grains. The silicate portions of the spherules are highly depleted in refractory lithophile elements (CaO, Al2O3, and TiO2 <0.04 wt%) and enriched in FeO, MnO, Cr2O3, and Na2O relative to the dominant, volatile-poor, magnesian chondrules from CH chondrites. The Fe/(Fe + Mg) ratio in the silicate portions of the spherules is positively correlated with Fe concentration in metal grains, which suggests that this correlation is not due to oxidation, reduction, or both of iron (FeOsil Fe-met) during melting of metal-silicate solid precursors. Rather, we suggest that this is a condensation signature of the precursors formed under oxidizing conditions. Each metal grain is compositionally uniform, but there are significant intergrain compositional variations: about 8-18 wt% Ni, <0.09 wt% Cr, and a sub-solar Co/Ni ratio. The precursor materials of these spherules were thus characterized by extreme elemental fractionations, which have not been observed in chondritic materials before. Particularly striking is the fractionation of Ni and Co in the rounded-to-euhedral metal grains, which has resulted in a Co/Ni ratio significantly below solar. The liquidus temperatures of the euhedral Fe,Ni metal grains are lower than those of the coexisting ferrous silicates, and we infer that the former crystallized in supercooled silicate melts. The metal grains are compositionally metastable; they are not decomposed into taenite and kamacite, which suggests fast postcrystallization cooling at temperatures below 970 K and lack of subsequent prolonged thermal metamorphism at temperatures above 400-500 K. C1 Univ Hawaii Manoa, Sch Ocean & Earth Sci & Technol, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Inst Mat Struct Sci, Tsukuba, Ibaraki 305, Japan. RP Krot, AN (reprint author), Univ Hawaii Manoa, Sch Ocean & Earth Sci & Technol, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. NR 21 TC 19 Z9 19 U1 0 U2 1 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD NOV PY 2000 VL 35 IS 6 BP 1249 EP 1258 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 385LF UT WOS:000166005400012 ER PT J AU Krot, AN Brearley, AJ Petaev, MI Kallemeyn, GW Sears, DWG Benoit, PH Hutcheon, ID Zolensky, ME Keil, K AF Krot, AN Brearley, AJ Petaev, MI Kallemeyn, GW Sears, DWG Benoit, PH Hutcheon, ID Zolensky, ME Keil, K TI Evidence for low-temperature growth of fayalite and hedenbergite in MacAlpine Hills 88107, an ungrouped carbonaceous chondrite related to the CM-CO clan SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID EARLY SOLAR-SYSTEM; COMPOSITIONAL CLASSIFICATION; AQUEOUS ALTERATION; ASTEROIDAL ALTERATION; OXYGEN-ISOTOPE; CV3 CHONDRITES; BASALT GLASS; NEBULA; MOKOIA; CONDENSATION AB The carbonaceous chondrite MacAlpine Hills (MAC) 88107 has bulk composition and mineralogy that are intermediate between those of CO and CM chondrites. This meteorite experienced minor alteration and a low degree of thermal metamorphism (petrologic type 3.1) and escaped post-accretional brecciation. The alteration resulted in the formation of fayalite (Fa(90-100)), Al-free hedenbergite (similar to Fs(50)Wo(50)), phyllosilicates (saponite-serpentine intergrowths), magnetite, and Ni-bearing sulfides (pyrrhotite and pentlandite). Fayalite and hedenbergite typically occur as veins, which start at the opaque nodules in the chondrule peripheries, crosscut fine-grained rims and either terminate at the boundaries with the neighboring fine-grained rims or continue as layers between these rims. These observations suggest that fayalite and hedenbergite crystallized after accretion and compaction of the fine-grained rims. Fayalite also overgrows isolated forsteritic (Fa(1-5)) and fayalitic (Fa(20-40)) olivine grains without any evidence for Fe-Mg interdiffusion; it also replaces massive magnetite-sulfide grains. The initial Mn-53/Mn-55 ratio of (1.58 +/- 0.26) x 10(-6) in the MAC 88107 fayalite corresponds to an age difference between the formation of fayalite and refractory inclusions in Allende of either similar to9 or 18 Ma, depending upon the value of the solar system initial abundance of Mn-53 used in age calculations. Formation of secondary fayalite and hedenbergite requires mobilization and transport of Ca, Si, and Fe either through a high-temperature gaseous phase (Hua and Buseck, 1995) or low-temperature aqueous solution (Krot et al., 1998a,b). The high-temperature nebular model for the origin of fayalite (Hua and Buseck, 1995) fails to explain (a) formation of fayalite-hedenbergite assemblages after accretion of fine-grained rims that lack any evidence for high-temperature processing; (b) extreme fractionation of refractory lithophile elements of similar volatility, Ca and Al, in hedenbergite; and (c) absence of Fe-Mg interdiffusion along fayalite-forsterite boundaries. We conclude that fayalite and hedenbergite in MAC 88107 formed during late-stage, low-temperature (approximately 150-200 degreesC) aqueous alteration. The data for MAC 88107 extend the evidence for an early onset of aqueous activity on chondrite parent bodies and reinforce the conclusion that liquid water played an important role in the chemical and mineralogical evolution of the first chondritic planetesimals. C1 Univ Hawaii, Sch Ocean & Earth Sci & Technol, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. Univ New Mexico, Albuquerque, NM 87131 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Tokyo Metropolitan Univ, Dept Math, Grad Sch Sci, Tokyo 1920397, Japan. Univ Arkansas, Dept Chem & Biochem, Fayetteville, AR 72701 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Krot, AN (reprint author), Univ Hawaii, Sch Ocean & Earth Sci & Technol, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. NR 59 TC 27 Z9 27 U1 1 U2 5 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD NOV PY 2000 VL 35 IS 6 BP 1365 EP 1386 PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 385LF UT WOS:000166005400021 ER PT J AU Rosenbaum, HC Brownell, RL Brown, MW Schaeff, C Portway, V White, BN Malik, S Pastene, LA Patenaude, NJ Baker, CS Goto, M Best, PB Clapham, PJ Hamilton, P Moore, M Payne, R Rowntree, V Tynan, CT Bannister, JL DeSalle, R AF Rosenbaum, HC Brownell, RL Brown, MW Schaeff, C Portway, V White, BN Malik, S Pastene, LA Patenaude, NJ Baker, CS Goto, M Best, PB Clapham, PJ Hamilton, P Moore, M Payne, R Rowntree, V Tynan, CT Bannister, JL DeSalle, R TI World-wide genetic differentiation of Eubalaena: questioning the number of right whale species SO MOLECULAR ECOLOGY LA English DT Article DE cetaceans; conservation; phylogeny; right whales; taxonomy ID MITOCHONDRIAL-DNA; HUMPBACK WHALES; BALEEN WHALES; EVOLUTIONARY SIGNIFICANCE; POPULATION-STRUCTURE; CONSERVATION; HAPLOTYPES; SEQUENCES; AUSTRALIS; GLACIALIS AB Few studies have examined systematic relationships of right whales (Eubalaena spp.) since the original species descriptions, even though they are one of the most endangered large whales. Little morphological evidence exists to support the current species designations for Eubalaena glacialis in the northern hemisphere and E. australis in the southern hemisphere. Differences in migratory behaviour or antitropical distribution between right whales in each hemisphere are considered a barrier to gene flow and maintain the current species distinctions and geographical populations. However, these distinctions between populations have remained controversial and no study has included an analysis of all right whales from the three major ocean basins. To address issues of genetic differentiation and relationships among right whales, we have compiled a database of mitochondrial DNA control region sequences from right whales representing populations in all three ocean basins that consist of: western North Atlantic E. glacialis, multiple geographically distributed populations of E. australis and the first molecular analysis of historical and recent samples of E. glacialis from the western and eastern North Pacific Ocean. Diagnostic characters, as well as phylogenetic and phylogeographic analyses, support the possibility that three distinct maternal lineages exist in right whales, with North Pacific E. glacialis being more closely related to E. australis than to North Atlantic E. glacialis. Our genetic results provide unequivocal character support for the two usually recognized species and a third distinct genetic lineage in the North Pacific under the Phylogenetic Species Concept, as well as levels of genetic diversity among right whales world-wide. C1 Amer Museum Nat Hist, Mol Systemat Lab, New York, NY 10024 USA. Wildlife Conservat Soc, Sci Resource Ctr, Bronx, NY 10460 USA. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. Ctr Coastal Studies, Provincetown, MA 02657 USA. E Coast Ecosyst, Freeport, NS B0V 1B0, Canada. American Univ, Dept Biol, Washington, DC 20016 USA. Smithsonian Inst, Natl Zool Pk, Mol Genet Lab, Washington, DC 20560 USA. McMaster Univ, Dept Biol, Hamilton, ON L8S 4K1, Canada. Inst Cetacean Res, Chuo Ku, Tokyo 1040055, Japan. Univ Auckland, Sch Biol Sci, Ecol & Evolut Grp, Auckland 1, New Zealand. Univ Pretoria, S African Museum, Mammal Res Inst, ZA-8000 Cape Town, South Africa. Natl Marine Fisheries Serv, NEFSC, Woods Hole, MA 02543 USA. New England Aquarium, Boston, MA 02110 USA. Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. Whale Conservat Inst, Lincoln, MA 01773 USA. Univ Washington, Natl Marine Mammal Lab, Joint Inst Study Atmosphere & Ocean, Seattle, WA 98115 USA. Western Australian Museum, Perth, WA 6000, Australia. RP Rosenbaum, HC (reprint author), Amer Museum Nat Hist, Mol Systemat Lab, 79th St & CPW, New York, NY 10024 USA. RI Moore, Michael/E-1707-2015; OI Moore, Michael/0000-0003-3074-6631; Schaeff, Catherine/0000-0003-3728-9402 NR 64 TC 66 Z9 74 U1 6 U2 34 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0962-1083 J9 MOL ECOL JI Mol. Ecol. PD NOV PY 2000 VL 9 IS 11 BP 1793 EP 1802 DI 10.1046/j.1365-294x.2000.01066.x PG 10 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 375MX UT WOS:000165404800010 PM 11091315 ER PT J AU Fonseca, DM LaPointe, DA Fleischer, RC AF Fonseca, DM LaPointe, DA Fleischer, RC TI Bottlenecks and multiple introductions: population genetics of the vector of avian malaria in Hawaii SO MOLECULAR ECOLOGY LA English DT Article DE A plus T-rich region; Culex quinquefasciatus; microsatellites; vector-mediated parasite-host interactions ID INSECTICIDE RESISTANCE GENES; MOSQUITO CULEX-PIPIENS; MITOCHONDRIAL-DNA; MICROSATELLITE; EVOLUTION; DROSOPHILA; FLOW; QUINQUEFASCIATUS; DIFFERENTIATION; DISTRIBUTIONS AB Avian malaria has had a profound impact on the demographics and behaviour of Hawaiian forest birds since its vector, Culex quinquefasciatus the southern house mosquito, was first introduced to Hawaii around 1830. In order to understand the dynamics of the disease in Hawaii and gain insights into the evolution of vector-mediated parasite-host interactions in general we studied the population genetics of Cx. Quinquefasciatus in the Hawaiian Islands. We used both microsatellite and mitochondrial loci. Not surprisingly we found that mosquitoes in Midway, a small island in the Western group, are quite distinct from the populations in the main Hawaiian Islands. However, we also found that in general mosquito populations are relatively isolated even among the main islands, in particular between Hawaii (the Big Island) and the remaining Hawaiian Islands. We found evidence of bottlenecks among populations within the Big Island and an excess of alleles in Maul, the site of the original introduction. The mitochondrial diversity was typically low but higher than expected. The current distribution of mitochondrial haplotypes combined with the microsatellite information lead us to conclude that there have been several introductions and to speculate on some processes that may be responsible for the current population genetics of vectors of avian malaria in Hawaii. C1 Smithsonian Inst, Natl Zool Pk, Dept Zool Res, Mol Genet Lab, Washington, DC 20008 USA. USGS, Wildlife Dis Lab, BRD, PIERC, Hawaii Natl Pk, HI 96718 USA. RP Fonseca, DM (reprint author), MSC Smithsonian Inst, Walter Reed Biosystemat Unit, 4210 Silver Hill Rd, Suitland, MD 20746 USA. RI Fonseca, Dina/B-9951-2011; OI Fonseca, Dina/0000-0003-4726-7100; LaPointe, Dennis/0000-0002-6323-263X NR 52 TC 59 Z9 61 U1 0 U2 17 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0962-1083 J9 MOL ECOL JI Mol. Ecol. PD NOV PY 2000 VL 9 IS 11 BP 1803 EP 1814 DI 10.1046/j.1365-294x.2000.01070.x PG 12 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 375MX UT WOS:000165404800011 PM 11091316 ER PT J AU Blackman, EG Field, GB AF Blackman, EG Field, GB TI Coronal activity from dynamos in astrophysical rotators SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE accretion, accretion discs; magnetic fields; Sun : corona; stars : coronae; stars : magnetic fields; galaxies : Seyfert ID X-RAY-SPECTRA; MAGNETIC HELICITY; ACCRETION DISKS; SOLAR-WIND; NONLINEAR DYNAMO; GALACTIC NUCLEI; TURBULENCE; FIELD; RECONNECTION; ENERGY AB We show that a steady mean-field dynamo in astrophysical rotators leads to an outflow of relative magnetic helicity and thus magnetic energy available for particle and wind acceleration in a corona. The connection between energy and magnetic helicity arises because mean-field generation is linked to an inverse cascade of magnetic helicity. To maintain a steady state in large magnetic Reynolds number rotators, there must then be an escape of relative magnetic helicity associated with the mean field, accompanied by an equal and opposite contribution from the fluctuating field. From the helicity flow, a lower limit on the magnetic energy deposited in the corona can be estimated. Steady coronal activity including the dissipation of magnetic energy, and formation of multi-scale helical structures therefore necessarily accompanies an internal dynamo. This highlights the importance of boundary conditions which allow this to occur for non-linear astrophysical dynamo simulations. Our theoretical estimate of the power delivered by a mean-field dynamo is consistent with that inferred from observations to be delivered to the solar corona, the Galactic corona, and Seyfert 1 AGN coronae. C1 CALTECH 130 33, Pasadena, CA 91125 USA. Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA. Harvard Smithsonian Ctr Astrophys CFA, Cambridge, MA 02139 USA. RP Blackman, EG (reprint author), CALTECH 130 33, Pasadena, CA 91125 USA. NR 56 TC 53 Z9 53 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD NOV 1 PY 2000 VL 318 IS 3 BP 724 EP 732 DI 10.1046/j.1365-8711.2000.03830.x PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 376JR UT WOS:000165454900013 ER PT J AU Gu, JP Hirsch, G Buenker, RJ Kimura, M Dutta, CM Nordlander, P AF Gu, JP Hirsch, G Buenker, RJ Kimura, M Dutta, CM Nordlander, P TI Charge transfer in F2+ ions colliding with He atoms below keV energies and its reverse process SO PHYSICAL REVIEW A LA English DT Article ID CORRELATED MOLECULAR CALCULATIONS; GAUSSIAN-BASIS SETS; CI CALCULATIONS; ELECTRON-CAPTURE; MATRIX-ELEMENTS; H+ IONS; COLLISIONS; EXTRAPOLATION; HYDROGEN AB Charge transfer processes in collisions of F2+ ions with He atoms were studied by using the molecular representation below 600 eV energies. The ground F2+(S-4) State and one excited F2+(D-2) state are considered as the initial channels in order to examine the effect of the excited state. We have also investigated charge transfer processes in the reverse ion-ion collisions. Cross sections for nonradiative charge transfer in the ground quartet state F2++He collisions are found to increase gradually with the impact energy and reach around 2 x 10(-16) cm(2) at 558 eV, while those from the doublet state also show a gradual increase and stay nearly constant with 1.2 x 10(-16) cm(2) at the same energy. Cross sections for the reverse processes for both symmetries are found to be very small with a magnitude less than 10(-19) cm(2) due to the strong Coulomb repulsion between two ions, but rapidly increase as the collision energy increases to reach 3 x 10(-17) and 10(-17) cm(2) for the quartet and doublet manifolds, respectively, at the highest energy studied. C1 Berg Univ Gesamthsch Wuppertal, D-42097 Wuppertal, Germany. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Yamaguchi Univ, Grad Sch Sci & Engn, Yamaguchi 7558611, Japan. Rice Univ, Dept Phys, Houston, TX 77251 USA. Rice Univ, Rice Quantum Inst, Houston, TX 77251 USA. RP Gu, JP (reprint author), Berg Univ Gesamthsch Wuppertal, D-42097 Wuppertal, Germany. RI Nordlander, Peter/A-2560-2008 OI Nordlander, Peter/0000-0002-1633-2937 NR 18 TC 0 Z9 0 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 2000 VL 62 IS 5 BP art. no. EP 052720 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 371VW UT WOS:000165200800077 ER PT J AU Lattig, P Cairns, SD AF Lattig, P Cairns, SD TI A new species of Tethocyathus (Cnidaria : Anthozoa : Scleractinia : Caryophylliidae), a trans-isthmian azooxanthellate species SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article ID PANAMA AB A new species of Tethocyathus is described, T. prahli, characterized by having a tympaniform corallum shape and no fossa. Specimens were found living at 310 m in the Colombian Caribbean, 303-333 m at Cocos Island (Pacific Costa Rica), and from the early Pleistocene of Pacific Panama, suggesting a relictual distribution of a previously more widespread species. Tethocyathus prahli is probably unique among the Scleractinia in having a non-cosmopolitan trans-isthmian distribution. The diagnosis of the genus Tethocyathus is emended to conform more closely to that of the type species. C1 Inst Invest Marinas & Costeras, Cerro Punta De Betin, Santa Marta, Colombia. Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. RP Lattig, P (reprint author), Inst Invest Marinas & Costeras, AA 10-16, Cerro Punta De Betin, Santa Marta, Colombia. NR 19 TC 7 Z9 9 U1 0 U2 0 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD NOV 1 PY 2000 VL 113 IS 3 BP 590 EP 595 PG 6 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 373JG UT WOS:000165285300002 ER PT J AU Bayer, FM AF Bayer, FM TI A new species of Leptogorgia from the eastern Pacific (Coelenterata : Octocorallia : Holaxonia) SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article AB Leptogorgia styx, a new species of the holaxonian family Gorgoniidae from the eastern Pacific inhabiting waters unusually deep for this genus is described and illustrated. Scanning electron micrographs of sclerites and morphology of axial mineral are presented. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. RP Bayer, FM (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. NR 14 TC 7 Z9 7 U1 1 U2 2 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD NOV 1 PY 2000 VL 113 IS 3 BP 609 EP 616 PG 8 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 373JG UT WOS:000165285300004 ER PT J AU Kornicker, LS Grabe, SA AF Kornicker, LS Grabe, SA TI Description of Eusarsiella tampa, a new species from Tampa Bay (Gulf of Mexico), Florida (Crustacea : Ostracoda : Myodocopina : Sarsiellidae) SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article AB The carapace and appendages of a new species of myodocopid ostracode, Eusarsiella tampa, from Tampa Bay (Gulf of Mexico), Florida, are described and illustrated. The new species is a member of the family Sarsiellidae, subfamily Sarsiellinae. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. Environm Protect Commiss, Tampa, FL 33605 USA. RP Kornicker, LS (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. NR 4 TC 2 Z9 2 U1 0 U2 1 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD NOV 1 PY 2000 VL 113 IS 3 BP 661 EP 669 PG 9 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 373JG UT WOS:000165285300009 ER PT J AU Campos, E Manning, RB AF Campos, E Manning, RB TI The identities of Pinnotheres nudus Holmes, 1895 and P-nudus sensu Weymouth, 1910 (Crustacea : Decapoda : Pinnotheridae) SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article ID BRACHYURA; GENUS AB The eastern Pacific species Pinnotheres nudus Holmes, 1895 is synonymized with Opisthopus transversus Rathbun, 1893. Pinnotheres nudus sensu Weymouth, 1910, named P. holmesi by Rathbun in 1918, also from the eastern Pacific, is shown to be a synonym of the western Atlantic Zaops geddesi (Miers, 1880), the second species to be assigned to the genus Zaops Rathbun, 1900. C1 Univ Autonoma Baja California, Fac Ciencias, Ensenada 22800, Baja California, Mexico. Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. RP Campos, E (reprint author), Univ Autonoma Baja California, Fac Ciencias, Apartado Postal 2300, Ensenada 22800, Baja California, Mexico. NR 25 TC 7 Z9 7 U1 0 U2 0 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD NOV 1 PY 2000 VL 113 IS 3 BP 799 EP 805 PG 7 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 373JG UT WOS:000165285300022 ER PT J AU Graves, GR AF Graves, GR TI Taxonomic notes on hummingbirds (Aves : Trochilidae). 3. Heliangelus violicollis Salvin, 1891 is a color variant of Heliangelus strophianus (Gould, 1846) SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article ID INTERGENERIC HYBRID; TROCHILIDAE; AVES; DIAGNOSES; SYSTEMATICS; ORIGIN AB The holotype of Heliangelus violicollis Salvin, 1891, reportedly from "Sarayacu" on the Amazonian slope of the Ecuadorian Andes, is hypothesized to be a color variant of Heliangelus strophianus (Gould, 1846) from the Pacific slope. A second specimen identified by Salvin as an immature male H. violicollis represents a female H. strophianus in typical definitive plumage. Analysis of plumage color and external measurements revealed no credible evidence for a hybrid origin of H. violicollis. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Vertebrate Zool, Washington, DC 20560 USA. RP Graves, GR (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Vertebrate Zool, Washington, DC 20560 USA. NR 36 TC 2 Z9 2 U1 0 U2 2 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD NOV 1 PY 2000 VL 113 IS 3 BP 836 EP 842 PG 7 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 373JG UT WOS:000165285300028 ER PT J AU Dorr, LJ Whittemore, AT AF Dorr, LJ Whittemore, AT TI Ada Nesta Dunn Ewan (1908-2000) - In memoriam SO TAXON LA English DT Biographical-Item C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, Washington, DC 20560 USA. US Natl Arboretum, Washington, DC 20002 USA. RP Dorr, LJ (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, MRC-166, Washington, DC 20560 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU INT ASSOC PLANT TAXONOMY PI BERLIN PA BOTANISCHER GARTEN BOTANISCHES MUSEUM BERLIN-DAHLEM, KONIGIN-LUISE-STRABE 6-8, D-14191 BERLIN, GERMANY SN 0040-0262 J9 TAXON JI Taxon PD NOV PY 2000 VL 49 IS 4 BP 817 EP 818 PG 2 WC Plant Sciences; Evolutionary Biology SC Plant Sciences; Evolutionary Biology GA 387UQ UT WOS:000166140600014 ER PT J AU Laurance, WF AF Laurance, WF TI Cut and run: the dramatic rise of transnational logging in the tropics SO TRENDS IN ECOLOGY & EVOLUTION LA English DT Editorial Material ID MANAGEMENT; FRONTIER; FOREST; AMAZON C1 Smithsonian Trop Res Inst, Balboa, Panama. Natl Inst Amazonian Res, INPA, Biol Dynam Forest Fragments Project, BR-69011970 Manaus, Amazonas, Brazil. RP Laurance, WF (reprint author), Smithsonian Trop Res Inst, Apartado 2072, Balboa, Panama. RI Laurance, William/B-2709-2012 NR 16 TC 17 Z9 17 U1 0 U2 5 PU ELSEVIER SCIENCE LONDON PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 0169-5347 J9 TRENDS ECOL EVOL JI Trends Ecol. Evol. PD NOV PY 2000 VL 15 IS 11 BP 433 EP 434 DI 10.1016/S0169-5347(00)01962-5 PG 2 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA 370KN UT WOS:000165122400001 ER PT J AU Marsden, BG AF Marsden, BG TI Astronomy - The red ragged edge SO NATURE LA English DT Editorial Material C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Marsden, BG (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM bmarsden@cfa.harvard.edu NR 9 TC 2 Z9 3 U1 0 U2 0 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD OCT 26 PY 2000 VL 407 IS 6807 BP 952 EP 955 DI 10.1038/35039651 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 366XX UT WOS:000090032500025 PM 11069163 ER PT J AU Torii, K Slane, PO Kinugasa, K Hashimotodani, K Tsunemi, H AF Torii, K Slane, PO Kinugasa, K Hashimotodani, K Tsunemi, H TI ASCA observations of the crab-like supernova remnant 3C 58 SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN LA English DT Article DE ISM : individual (3C 58); supernova remnants; X rays : ISM ID X-RAY-EMISSION; GAS IMAGING SPECTROMETER; NEUTRON-STARS; MILLISECOND PULSAR; MAGNETIC-FIELD; NOVA REMNANTS; VELA PULSAR; BOARD ASCA; NEBULA; LUMINOSITY AB We present here X-ray observation of a Crab-like supernova remnant (SNR) 3C 58 with ASCA. We find that the integrated energy spectrum over the nebula is consistent with previous results, showing a power-law spectrum with the photon index of gamma = 2.2-2.4, modified by interstellar absorption of about (3-4) x 10(21) cm(-2). The inclusion of a blackbody component, which is attributable to the central compact source, significantly improves the spectral fit. Stringent upper limits for any line emitting thin hot plasma are established. We find for the first time that the nebular spectrum is harder in the central part of the SNR, becoming softer toward the periphery, while the absorption column is uniform across the nebula. Correspondingly, the nebular size decreases with increasing photon energy, which is a steeper function of the radius than that of the Crab nebula. The results are compared with synchrotron energy-loss models, and the nature of the putative pulsar is discussed. A timing analysis was performed to search for pulsed X-ray emission from the central compact source. No significant pulsations were observed; and we present the upper limit for the pulsed fraction. C1 NASDA TKSC SURP, Tsukuba, Ibaraki 3058505, Japan. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Gunma Astron Observ, Gunma 3770702, Japan. Osaka Univ, Grad Sch Sci, Dept Earth & Space Sci, Osaka 5600043, Japan. JST, CREST, Tsukuba, Ibaraki 3050047, Japan. RP NASDA TKSC SURP, 2-1-1 Sengen, Tsukuba, Ibaraki 3058505, Japan. EM torii.kenichi@nasda.go.jp NR 65 TC 35 Z9 35 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0004-6264 EI 2053-051X J9 PUBL ASTRON SOC JPN JI Publ. Astron. Soc. Jpn. PD OCT 25 PY 2000 VL 52 IS 5 BP 875 EP 885 DI 10.1093/pasj/52.5.875 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 370JN UT WOS:000165119900018 ER PT J AU Ebeling, H Edge, AC Allen, SW Crawford, CS Fabian, AC Huchra, JP AF Ebeling, H Edge, AC Allen, SW Crawford, CS Fabian, AC Huchra, JP TI The ROSAT Brightest Cluster Sample - IV. The extended sample SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE surveys; galaxies : clusters : general; X-rays : galaxies ID ALL-SKY SURVEY; ABELL CLUSTERS; OPTICAL SPECTROSCOPY; REDSHIFT SURVEY; RICH CLUSTERS; GALAXIES; KINEMATICS; EVOLUTION; CATALOG AB We present a low-flux extension of the X-ray-selected ROSAT Brightest Cluster Sample (BCS) published in Paper I of this series. Lice the original BCS and employing an identical selection procedure, the BCS extension is compiled from ROSAT All-Sky Survey (RASS) data in the northern hemisphere (delta greater than or equal to 0 degrees) and at high Galactic latitudes (\b\ greater than or equal to 20 degrees). It comprises 99 X-ray-selected clusters of galaxies with measured redshifts z less than or equal to 0.3 (as well as eight more at z > 0.3) and total fluxes between 2.8 x 10(-12) and 4.4 x 10(-12) erg cm(-2) s(-1) in the 0.1-2.4 keV band (the latter value being the flux limit of the original BCS). The extension can be combined with the main sample published in 1998 to form the homogeneously selected extended BCS (eBCS), the largest and statistically best understood cluster sample to emerge from the PASS to date. The nominal completeness of the combined sample (defined with respect to a power-law fit to the bright end of the BCS logN-logS distribution) is relatively low at 75 per cent (compared with 90 per cent for the high-flux sample of Paper I). However, just as for the original BCS, this incompleteness can be accurately quantified, and thus statistically corrected for, as a function of X-ray luminosity and redshift. In addition to its importance for improved statistical studies of the properties of clusters in the local Universe, the low-flux extension of the BCS is also intended to serve as a finding list for X-ray-bright clusters in the northern hemisphere which we hope will prove useful in the preparation of cluster observations with the next generation of X-ray telescopes such as Chandra and XMM-Newton. An electronic version of the eBCS can be obtained from the following URL: http ://www.ifa.hawaii.edu/similar to ebeling/clusters/BCS.html. C1 Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Ebeling, H (reprint author), Max Planck Inst Extraterr Phys, Giessenbachstr, D-85740 Garching, Germany. NR 46 TC 249 Z9 250 U1 1 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD OCT 21 PY 2000 VL 318 IS 2 BP 333 EP 340 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 374BT UT WOS:000165325100003 ER PT J AU Kuraszkiewicz, J Wilkes, BJ Brandt, WN Vestergaard, M AF Kuraszkiewicz, J Wilkes, BJ Brandt, WN Vestergaard, M TI [O II] emission, eigenvector 1, and orientation in radio-quiet quasars SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; quasars : emission lines ID X-RAY-PROPERTIES; OPTICALLY SELECTED QUASARS; LINE SEYFERT-1 GALAXIES; ACTIVE GALACTIC NUCLEI; COMPLETE SAMPLE; UNIFIED MODELS; HOST GALAXIES; CATALOG; NGC-4258; AGN AB We present supportive evidence that the Boroson & Green eigenvector 1 is not driven by source orientation and further that both [O III] lambda 5007 and [O II] lambda 3727 are isotropically emitted in the radio-quiet sample of bright quasar survey (BQS) quasars, contrary to results found for radio-loud active galactic nuclei (AGNs). Studies of optical emission lines in quasars have revealed a striking set of correlations between various emission-line properties, known as the Boroson & Green eigenvector 1. Until recently it was generally accepted that eigenvector 1 does not depend on orientation, as it strongly correlates with [O III] lambda 5007 emission, thought to be an isotropic property. However, recent studies of radio-loud AGNs have questioned the isotropy of [O III] emission and concluded that [O III] lambda 3727 emission is isotropic. In this paper we investigate the relation between eigenvector 1 and [O III] emission in radio-quiet BQS quasars and readdress the issue of orientation as the driver of eigenvector 1. We account for the small blue bump present at [O II] wavelengths and subtract Fe II emission that contaminates [O III] emission. We find significant correlations between eigenvector 1 and orientation-independent [O II] emission, which implies that orientation does not drive eigenvector 1. The luminosities and equivalent widths of [O III] and [O II] correlate with one another, and the range in luminosities and equivalent widths is similar. This suggests that our radio-quiet BQS quasar sample is largely free of orientation-dependent obscuration and/or ionization effects. We conclude that neither the [O III] emission nor the [O II]/[O III] ratio are dependent on orientation in radio-quiet quasars, contrary to recent results found for radio-loud quasars. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Ohio State Univ, Columbus, OH 43120 USA. N Copernicus Astron Ctr, Warsaw, Poland. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Kuraszkiewicz, J (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Vestergaard, Marianne/M-5247-2014; Brandt, William/N-2844-2015; OI Vestergaard, Marianne/0000-0001-9191-9837; Brandt, William/0000-0002-0167-2453; Wilkes, Belinda/0000-0003-1809-2364 NR 37 TC 27 Z9 27 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2000 VL 542 IS 2 BP 631 EP 643 DI 10.1086/317018 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 369YN UT WOS:000165095500010 ER PT J AU Chartas, G Worrall, DM Birkinshaw, M Cresitello-Dittmar, M Cui, W Ghosh, KK Harris, DE Hooper, EJ Jauncey, DL Kim, DW Lovell, J Mathur, S Schwartz, DA Tingay, SJ Virani, SN Wilkes, BJ AF Chartas, G Worrall, DM Birkinshaw, M Cresitello-Dittmar, M Cui, W Ghosh, KK Harris, DE Hooper, EJ Jauncey, DL Kim, DW Lovell, J Mathur, S Schwartz, DA Tingay, SJ Virani, SN Wilkes, BJ TI The Chandra X-ray Observatory resolves the X-ray morphology and spectra of a jet in PKS 0637-752 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : jets; quasars : individual (PKS 0637-752); X-rays : galaxies ID RADIO; EMISSION; QUASARS AB The core-dominated radio-loud quasar PKS 0637-752 (z = 0.654) was the first celestial object observed with the Chandra X-Ray Observatory, offering the early surprise of the detection of a remarkable X-ray jet. Several observations with a variety of detector configurations contribute to a total exposure time with the Chandra ACIS of about 100 ks. A spatial analysis of all the available X-ray data, making use of Chandra's spatial resolving power of about 0".4, reveals a jet that extends about 10 " to the west of the nucleus. At least four X-ray knots are resolved along the jet, which contains about 5% of the overall X-ray luminosity of the source. Previous observations of PKS 0637-752 in the radio band had identified a kiloparsec-scale radio jet extending to the west of the quasar. The X-ray and radio jets are similar in shape, intensity distribution, and angular structure out to about 9", after which the X-ray brightness decreases more rapidly and the radio jet turns abruptly to the north. The X-ray luminosity of the total source is log L-X approximate to 45.8 ergs s(-1) (2-10 keV) and appears not to have changed since it was observed with ASCA in 1996 November. We present the results of fitting a variety of emission models to the observed spectral distribution, comment on the nonexistence of emission lines recently reported in the ASCA observations of PKS 0637 - 752, and briefly discuss plausible X-ray emission mechanisms. C1 Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Univ Bristol, Dept Phys, Bristol BS8 1TL, Avon, England. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. Australia Telescope Natl Facil, Epping, NSW 2121, Australia. Ohio State Univ, Columbus, OH 43210 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Chartas, G (reprint author), Penn State Univ, Dept Astron & Astrophys, 525 Davey Lab, University Pk, PA 16802 USA. RI Tingay, Steven/B-5271-2013; OI Cui, Wei/0000-0002-6324-5772; Wilkes, Belinda/0000-0003-1809-2364 NR 17 TC 122 Z9 122 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2000 VL 542 IS 2 BP 655 EP 666 DI 10.1086/317049 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 369YN UT WOS:000165095500012 ER PT J AU Kuraszkiewicz, J Wilkes, BJ Czerny, B Mathur, S AF Kuraszkiewicz, J Wilkes, BJ Czerny, B Mathur, S TI What do the ultraviolet spectra of narrow line Seyfert 1 galaxies tell us about their broad-line regions? SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion; accretion disks; galaxies : active; galaxies : Seyfert; ultraviolet : galaxies ID ACTIVE GALACTIC NUCLEI; X-RAY-PROPERTIES; MG-II ABSORPTION; EMISSION-LINES; ACCRETION DISKS; ENERGY-DISTRIBUTIONS; QUASAR SPECTRUM; MODEL; CONSTRAINTS; REDSHIFT AB We study the UV spectra of narrow-line Seyfert 1 (NLSy1) galaxies and compare them with "normal" active galactic nuclei. Similar to their optical lines, the NLSy1s show narrower UV lines. They are also characterized by weaker C IV lambda 1549 and C III lambda 1909 and stronger Al III lambda 1857 emission. These UV-line properties add to the optical and X-ray properties known to be part of the Boroson & Green eigenvector 1. We show that the steep soft X-rays, which characterize the NLSy1s SEDs, change the equilibrium of the two-phase cloud-intercloud medium, resulting in somewhat higher broad-line region cloud densities, lower ionization parameter, and larger broad-line region radii. These modified conditions can explain the unusual emission-line properties we find in NLSy1. Using a specific model of an accretion disk with corona presented by Witt, Czerny, & Zycki, we also show that the steep soft and hard X-ray continua can be explained if the L/L-Edd ratios are larger than in "normal" Sy1s/QSOs, strengthening earlier suggestions that the L/L-Edd is the physical parameter driving this eigenvector. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Nicholas Copernicus Astron Ctr, Warsaw, Poland. Ohio State Univ, Columbus, OH 43120 USA. RP Kuraszkiewicz, J (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Czerny, Bozena/A-2363-2015; OI Czerny, Bozena/0000-0001-5848-4333; Wilkes, Belinda/0000-0003-1809-2364 NR 72 TC 44 Z9 45 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2000 VL 542 IS 2 BP 692 EP 702 DI 10.1086/317013 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 369YN UT WOS:000165095500016 ER PT J AU Dickins, JE Irvine, WM Snell, RL Bergin, EA Schloerb, FP Pratap, P Miralles, MP AF Dickins, JE Irvine, WM Snell, RL Bergin, EA Schloerb, FP Pratap, P Miralles, MP TI A study of the physics and chemistry of L134N SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; ISM : individual (L134N); ISM : molecules ID DENSE INTERSTELLAR CLOUDS; INTER-STELLAR CLOUDS; COLLISIONAL EXCITATION; ROTATIONAL-EXCITATION; SULFUR-DIOXIDE; DARK CLOUDS; ASTROPHYSICAL INTEREST; MICROWAVE-SPECTRA; MOLECULAR CLOUDS; AMMONIA AB We have carried out a comprehensive and self-consistent study of the physical and chemical state of the core of the dark cloud L134N (L183), whose molecular abundances provide a standard against which chemical models may be compared. We used observations of the NH(3)(1, 1) and (2, 2) rotation-inversion transitions to estimate the kinetic temperature, which was found to be consistent with 10 K and not varying with position. Densities were determined from multitransition statistical equilibrium calculations for HC(3)N, N(2)H(+), and CS. The average density toward all lines of sight was 2 x 10(4) cm(-3). As found by previous studies, the emission from various molecular species peaks in different positions: SO and SO(2) peak west of the central position, which is the location of the strongest emission from (e.g.) N(2)H(+) and CH(3)OH, with a second peak occurring for NH(3) and HC(3)N to the north of the center. The most striking abundance variations occur in a north-south cut through the core center for HC(3)N, C(2)H, CS, SO, and SO(2). A north to south decrease in the abundance of HC(3)N and CS and a dramatic change in the CS/SO ratio, which has been shown to be a sensitive tracer of chemical evolutionary state, suggests that the north is at a younger evolutionary state than the south. Despite the "youth" of the N position, the CS/SO ratio suggests that it is still as "old" as or older than the most evolved region in TMC-1 (the northwest end of the ridge). C1 Univ Massachusetts, Five Coll Radio Astron Observ, Amherst, MA 01003 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. MIT, Haystack Observ, Westford, MA 01886 USA. RP Dickins, JE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 169-506, Pasadena, CA 91109 USA. EM James.Dickens@jpl.nasa.gov NR 67 TC 89 Z9 89 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2000 VL 542 IS 2 BP 870 EP 889 DI 10.1086/317040 PN 1 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 369YN UT WOS:000165095500031 ER PT J AU Kraemer, KE Jackson, JM Lane, AP Paglione, TAD AF Kraemer, KE Jackson, JM Lane, AP Paglione, TAD TI Properties of the photodissociated gas in NGC 6334 SO ASTROPHYSICAL JOURNAL LA English DT Article DE HII regions; ISM : individual (NGC 6334); stars : formation ID H-II REGIONS; FAR-INFRARED SPECTROSCOPY; STAR-FORMATION REGION; MOLECULAR CLOUDS; 158 MICRON; LINE EMISSION; NGC-6334; COMPLEX; DISK; PENETRATION AB To investigate the properties of photodissociated gas in strong radiation fields, the massive star formation region NGC 6334 has been mapped with the Far-Infrared Imaging Fabry-Perot Interferometer (FIFI) instrument in the far-infrared fine-structure transitions [C II] 158 mum, [O I] 146 mum, and [O I] 63 mum. Bright CC nl 158 mum emission is found throughout the cloud, whereas the CO I] 146 mum emission is associated only with the star-forming ridge. Comparison of the relative intensities of the lines with single-component photodissociation region models suggests densities of n(H) similar to 10(4) cm(-3). The models imply unphysically large radiation fields for three sources, particularly for NGC 6334A, which is probably caused by self-absorption in the [O I] 63 mum line. An alternative method for estimating physical conditions, based on the correlation between [C II] 158 mum and CO line intensities, is explored. This method implies hydrogen column densities of N-H greater than or similar to 10(22-23) cm(-2), which agree well with those from molecular excitation models. The relative distribution of the [C II] 158 mum and [O I] 146 mum emission supports clumpy photodissociation region models that suggest the [C II] 158 mum emission arises from interclump gas and thus should be more extended than the [O I] 146 mum emission that arises from the denser clumps. The spatial coincidence of [C II] 158 mum emission peaks with minima in the molecular gas emission indicates that at least some of the molecular holes contain photodissociated gas. The relative pressures of the ionized, photodissociated, and molecular gas are compared: the photodissociated and molecular gas are in approximate pressure equilibrium, but the ionized gas is overpressurized by at least an order of magnitude at the continuum sources. C1 USAF, Res Lab, Natl Res Council, VSBC, Hanscom AFB, MA 01731 USA. Boston Univ, Dept Astron, Boston, MA 02215 USA. Boston Univ, Inst Astrophys Res, Boston, MA 02215 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. RP Kraemer, KE (reprint author), USAF, Res Lab, Natl Res Council, VSBC, 29 Randolph Rd, Hanscom AFB, MA 01731 USA. OI Paglione, Tim/0000-0001-9139-0945; Kraemer, Kathleen/0000-0002-2626-7155 NR 54 TC 6 Z9 6 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2000 VL 542 IS 2 BP 946 EP 956 DI 10.1086/317015 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 369YN UT WOS:000165095500037 ER PT J AU Bloser, PF Grindlay, JE Barret, D Boirin, L AF Bloser, PF Grindlay, JE Barret, D Boirin, L TI RXTE studies of X-ray spectral variations with accretion rate in 4U 1915-05 SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; stars : individual (4U 1915-05); stars : neutron; X-rays : stars ID ASCA OBSERVATION; TIMING EXPLORER; BINARIES; DISCOVERY; PERIOD; COMPTONIZATION; XB-1916-053; ABSORPTION; EVOLUTION; EMISSION AB We present the results of detailed spectral studies of the ultracompact low-mass X-ray binary (LMXB) 4U 1915-05 carried out with the Rossi X-Ray Timing Explorer (RXTE) during 1996. 4U 1915-05 is an X-ray burster (XRB) known to exhibit a similar to 199 day modulation in its 2-12 keV flux. Observations were performed with the PCA and HEXTE instruments on RXTE at roughly one-month intervals to sample this long-term period and study accretion rate-related spectral changes. We obtain good fits with a model consisting of a blackbody and an exponentially cut-off power law. The spectral parameters are strongly correlated with both the broadband (2-50 keV) luminosity and the position in the color-color diagram, with the source moving from a low, hard state to a high, soft state as the accretion rate increases. The blackbody component appears to drive the spectral evolution. Our results are consistent with a geometry in which the soft component arises from an optically thick boundary layer and the hard component from an extended Comptonizing corona. Comparing our results with those of a similar study of the brighter source 4U 1820-30, we find that the two ultracompact LMXBs occupy similar spectral states even though the transitions occur at very different total luminosities. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Ctr Etud Spatiale Rayonnements, CNRS UPS, F-31028 Toulouse 04, France. RP Bloser, PF (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM pbloser@cfa.harvard.edu; Didier.Barret@cesr.fr NR 47 TC 16 Z9 16 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2000 VL 542 IS 2 BP 989 EP 999 DI 10.1086/317035 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 369YN UT WOS:000165095500042 ER PT J AU Bloser, PF Grindlay, JE Kaaret, P Zhang, W Smale, AP Barret, D AF Bloser, PF Grindlay, JE Kaaret, P Zhang, W Smale, AP Barret, D TI RXTE studies of long-term X-ray spectral variations in 4U 1820-30 SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; stars : individual (4U 1820-30); stars : neutron; X-rays : stars ID QUASI-PERIODIC OSCILLATIONS; CLUSTER NGC 6624; NEUTRON-STARS; TIMING EXPLORER; ACCRETION DISKS; BLACK-HOLES; BINARIES; DISCOVERY; EMISSION; COMPTONIZATION AB We present the results of detailed spectral studies of the ultracompact low mass X-ray binary (LMXB) 4U 1820-30 carried out with the Rossi X-ray Timing Explorer (RXTE) during 1996-1997. 4U 1820-30 is an "atoll" source X-ray burster (XRB) located in the globular cluster NGC 6624. It is known to have an 11 minute binary period and a similar to 176 day modulation in its 2-12 keV flux. Observations were made with the PCA and HEXTE instruments on RXTE at roughly one-month intervals to sample this longterm period and study flux-related spectral changes. We find that the 176 day period corresponds to normal atoll source motion in the color-color diagram, indicating that the long period is due to mass accretion rate changes. There are clear correlations between our fitted spectral parameters and both the broadband (2-50 keV) flux and the position in the color-color diagram, as described by the parameter S, introduced by Mendez et al. The hard X-ray tail becomes more prominent at low flux levels as the source moves into the island state. In addition, we find a strong correlation between the position in the color-color diagram and the frequencies of the kilohertz quasi-periodic oscillations (kHz QPOs) reported by Zhang et al. This lends further support to the notion that evidence for the last stable orbit in the accretion disk of 4U 1820-30 has been observed. For a model consisting of Comptonization of cool photons by hot electrons plus an additional blackbody component, we report an abrupt change in the spectral parameters at the same accretion rate at which the kHz QPOs disappear, suggesting a change in the accretion flow that affects both the spectrum and the timing properties. For a model consisting of a multicolor disk blackbody plus a cut-off power law, we find that the inner disk radius reaches a minimum at the same accretion rate at which the kHz QPO frequency saturates, as expected if the disk reaches the last stable orbit. Both models face theoretical and observational problems when interpreted physically for this system. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Ctr Etud Spatiale Rayonnements, CNRS UPS, F-31028 Toulouse 04, France. RP Bloser, PF (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM pbloser@cfa.harvard.edu; zhang@xancusl0.gsfc.nasa.gov; Didier.Barret@cesr.fr RI Zhang, William/D-3535-2012 NR 64 TC 48 Z9 48 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2000 VL 542 IS 2 BP 1000 EP 1015 DI 10.1086/317019 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 369YN UT WOS:000165095500043 ER PT J AU Antiochos, SK DeLuca, EE Golub, L McMullen, RA AF Antiochos, SK DeLuca, EE Golub, L McMullen, RA TI Determination of flare heating and cooling using the Transition Region and Coronal Explorer SO ASTROPHYSICAL JOURNAL LA English DT Article DE sun : flares; sun : transition region; sun : X-rays, gamma rays ID PLASMA AB We describe how the Transition Region and Coronal Explorer 171 Angstrom observations can be used to determine the properties of flare-loop heating. The key point is that the evolution of a loop transition region (TR) is much easier to measure quantitatively than the bulk flare plasma because the TR emission originates from an unobscured source with simple geometry. We derive general analytic expressions for the evolution of a flare-loop TR that, in principle, permit a determination of the heating function from the observations. These results are compared with observations of the 1998 September 20 flare. We find that the observed evolution of the flare ribbons is in good agreement with our model for the evaporative cooling of flare loops and that the heating in these loops is incompatible with the assumption of spatial uniformity. C1 USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. RP Antiochos, SK (reprint author), USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. RI Antiochos, Spiro/D-4668-2012; DeLuca, Edward/L-7534-2013 OI Antiochos, Spiro/0000-0003-0176-4312; DeLuca, Edward/0000-0001-7416-2895 NR 9 TC 10 Z9 10 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2000 VL 542 IS 2 BP L151 EP L154 DI 10.1086/312927 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 369YQ UT WOS:000165095700019 ER PT J AU Furuya, RS Kitamura, Y Wootten, HA Claussen, MJ Saito, M Marvel, KB Kawabe, R AF Furuya, RS Kitamura, Y Wootten, HA Claussen, MJ Saito, M Marvel, KB Kawabe, R TI A microjet: A protostar's cry at birth SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : jets and outflows; masers; stars : evolution; stars : individual (S106 FIR); stars : pre-main-sequence; techniques : interferometric ID CARBON-MONOXIDE; STAR FORMATION; H2O MASERS; S106; REGION; OUTFLOW; GAS; JET AB We report the discovery, through Very Long Baseline Array (VLBA) observations of H2O masers at 22 GHz, of a newly ejected extraordinarily compact protostellar jet-a microjet-from the class 0 protostar S106 LIR. The sub-AU resolution VLBA observations revealed the presence of a U-shaped distribution of the masers in the western blue;shifted cluster. It has a length of 4 AU, has a width of 3 AU, and is located at a distance of 25 AU from the assumed position of the star around the middle point of the two maser clusters. The U-shaped distribution is considered to be a "microbowshock" created by the impact of the microjet on the ambient cloud medium. We succeeded in tracking the proper motion of the microbowshock; its velocity ranges from 25 to 45 km s(-1), estimated from the proper motions and line-of-sight velocities. In addition, this source stands unique among all 40 known class 0 sources in its lack of an extensive molecular outflow, evidenced by our sensitive multitransition CO searches with 10 sigma upper limits of similar to 10(-6) M-. km(-1) s. We propose that S106 FIR is an archetype of the youngest evolutionary class, a protostar observed just after the creation of the protostellar jet. C1 Grad Univ Adv Studies, Dept Astron Sci, Nobeyama Radio Observ, Minamisa Ku, Nagano 3841305, Japan. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 2298510, Japan. Natl Radio Astron Observ, Charlottesville, VA 22903 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Amer Astron Soc, Execut Off, Washington, DC 20009 USA. Natl Astron Observ, Nobeyama Radio Observ, Minamisa Ku, Nagano 3841305, Japan. RP Furuya, RS (reprint author), Osservatorio Astrofis Arcetri, Largo E Fermi 5, I-50125 Florence, Italy. NR 24 TC 48 Z9 48 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2000 VL 542 IS 2 BP L135 EP L138 DI 10.1086/312925 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 369YQ UT WOS:000165095700015 ER PT J AU Takahashi, T Kataoka, J Madejski, G Mattox, J Urry, CM Wagner, S Aharonian, F Catanese, M Chiappetti, L Coppi, P Degrange, B Fossati, G Kubo, H Krawczynski, H Makino, F Marshall, H Maraschi, L Piron, F Remillard, R Takahara, F Tashiro, M Terasranta, H Weekes, T AF Takahashi, T Kataoka, J Madejski, G Mattox, J Urry, CM Wagner, S Aharonian, F Catanese, M Chiappetti, L Coppi, P Degrange, B Fossati, G Kubo, H Krawczynski, H Makino, F Marshall, H Maraschi, L Piron, F Remillard, R Takahara, F Tashiro, M Terasranta, H Weekes, T TI Complex spectral variability from intensive multiwavelength monitoring of Markarian 421 in 1998 SO ASTROPHYSICAL JOURNAL LA English DT Article DE BL Lacertae objects : general; BL Lacertae objects : individual (Markarian 421); X-rays : general ID ACTIVE GALACTIC NUCLEI; X-RAY; ENERGY-DISTRIBUTIONS; RAPID VARIABILITY; BLAZARS; EMISSION; ACCELERATION; FLARE AB We conducted a multifrequency campaign for the TeV blazar Markarian 421 in 1998 April. The campaign started from a pronounced high-amplitude flare recorded by BeppoSAX and Whipple; the ASCA observation started 3 days later. In the X-ray data, we detected multiple flares, occurring on timescales of about 1 day. ASCA data clearly reveal spectral variability. The comparison of the data from ASCA, the Extreme Ultraviolet Explorer, and the Rossi X-Ray Timing Explorer indicates that the variability amplitudes in the low-energy synchrotron component are larger at higher photon energies. In TeV gamma -rays, large intraday variations-which were correlated with the X-ray flux-were observed when results from three Cerenkov telescopes were combined. The rms variability of TeV gamma -rays was similar to that observed in hard X-rays, above 10 keV. The X-ray light curve reveals flares that are almost symmetric for most cases, implying that the dominant timescale is the light crossing time through the emitting region. The structure function analysis based on the continuous X-ray light curve of 7 days indicates that the characteristic timescale is similar to0.5 days. The analysis of ASCA light curves in various energy bands appears to show both soft (positive) and hard (negative) lags. These may not be real, as systematic effects could also produce these lags, which are all much smaller than an orbit. If the lags of both signs are red, these imply that the particle acceleration and X-ray cooling timescales are similar. C1 Inst Space & Astronaut Sci, Sagamihara, Kanagawa 2298510, Japan. Univ Tokyo, Dept Phys, Tokyo 1130033, Japan. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Boston Univ, Dept Astron, Boston, MA 02215 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Landessternwarte Heidelberg, D-69117 Heidelberg, Germany. Max Planck Inst Kernphys, D-69029 Heidelberg, Germany. Harvard Smithsonian Ctr Astrophys, Fred Lawrence Whipple Observ, Amado, AZ 85645 USA. CNR, Inst Fis Cosm, I-20133 Milan, Italy. Yale Univ, Dept Astron, New Haven, CT 06520 USA. Ecole Polytech, Lab Phys Nucl Haute Energies, Palaiseau, France. Univ Calif San Diego, Ctr Astrophys & Space Sci, La Jolla, CA 92093 USA. Tokyo Inst Technol, Dept Phys, Tokyo 1528551, Japan. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Osservatorio Astron Brera, I-20121 Milan, Italy. Osaka Univ, Dept Earth & Space Sci, Osaka, Japan. Metsahove Radio Observ, Kylmala, Finland. RP Takahashi, T (reprint author), Inst Space & Astronaut Sci, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 2298510, Japan. RI Fossati, Giovanni/A-5841-2009; Tashiro, Makoto/J-4562-2012; Urry, Claudia/G-7381-2011 OI Urry, Claudia/0000-0002-0745-9792 NR 30 TC 77 Z9 77 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2000 VL 542 IS 2 BP L105 EP L109 DI 10.1086/312929 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 369YQ UT WOS:000165095700008 ER PT J AU Roubik, DW AF Roubik, DW TI The bees of the world SO SCIENCE LA English DT Book Review C1 Smithsonian Trop Res Inst, Balboa, Panama. RP Roubik, DW (reprint author), Smithsonian Trop Res Inst, Balboa, Panama. NR 1 TC 0 Z9 0 U1 1 U2 5 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD OCT 20 PY 2000 VL 290 IS 5491 BP 461 EP 461 DI 10.1126/science.290.5491.461 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 365HN UT WOS:000089946000032 ER PT J AU Piperno, DR Ranere, AJ Holst, I Hansell, P AF Piperno, DR Ranere, AJ Holst, I Hansell, P TI Starch grains reveal early root crop horticulture in the Panamanian tropical forest SO NATURE LA English DT Article ID MANIHOT AB Native American populations are known to have cultivated a large number of plants and domesticated them for their starch-rich underground organs(1). Suggestions(2,3) that the likely source of many of these crops, the tropical forest, was an early and influential centre of plant husbandry have long been controversial(4-6) because the organic remains of roots and tubers are poorly preserved in archaeological sediments from the humid tropics. Here we report the occurrence of starch grains identifiable as manioc (Manihot esculenta Crantz), yams (Dioscorea sp.) and arrowroot (Maranta arundinacea L.) on assemblages of plant milling stones from preceramic horizons at the Aguadulce Shelter, Panama, dated between 7,000 and 5,000 years before present (BP). The artefacts also contain maize starch (Zea mays L.), indicating that early horticultural systems in this region were mixtures of root and seed crops. The data provide the earliest direct evidence for root crop cultivation in the Americas, and support an ancient and independent emergence of plant domestication in the lowland Neotropical forest. C1 Smithsonian Trop Res Inst, Balboa, Panama. Temple Univ, Dept Anthropol, Philadelphia, PA 19122 USA. RP Piperno, DR (reprint author), Smithsonian Trop Res Inst, Box 2072, Balboa, Panama. NR 27 TC 166 Z9 185 U1 4 U2 20 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD OCT 19 PY 2000 VL 407 IS 6806 BP 894 EP 897 DI 10.1038/35038055 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 364PZ UT WOS:000089901900048 PM 11057665 ER PT J AU Kalfatovic, MR AF Kalfatovic, MR TI Magician of the modern: Chick Austin and the transformation of the arts in America. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst Lib, Washington, DC USA. RP Kalfatovic, MR (reprint author), Smithsonian Inst Lib, Washington, DC USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD OCT 15 PY 2000 VL 125 IS 17 BP 64 EP 64 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA 363PA UT WOS:000089842700062 ER PT J AU Graham, LH Swanson, WF Brown, JL AF Graham, LH Swanson, WF Brown, JL TI Chorionic gonadotropin administration in domestic cats causes an abnormal endocrine environment that disrupts oviductal embryo transport SO THERIOGENOLOGY LA English DT Article DE domestic cat; fecal steroids; artificial insemination; chorionic gonadotropins; embryo transport ID FECAL STEROID ANALYSIS; OVARIAN ACTIVITY; FELIS-CATUS; ADRENOCORTICAL FUNCTION; INVITRO FERTILIZATION; CIRCULATING HORMONES; SEXUAL-BEHAVIOR; LUTEAL FUNCTION; ESTRUS; ESTRADIOL-17-BETA AB Fecal steroid analysis was used to investigate relationships between endocrine parameters and embryo characteristics in domestic cats subjected to chorionic gonadotropin stimulation and artificial insemination (AI). In Study 1, normal endocrine patterns were assessed in 12 cycling domestic queens. Fecal estradiol (E) patterns established an anovulatory cycle length of 18.3 +/- 0.4 d with estrus lasting 6.3 +/- 0.3 d. Eight females (67%) exhibited at least one spontaneous ovulation based on sustained increases in fecal progestagens (P). In Study 2, queens were mated during natural estrus (NE, n = 5) or subjected to exogenous i.m. gonadotropin stimulation, 100 TU eCG followed by 75 IU hCG 80 h later, (GS, n = 5). Compared with NE queens, fecal E concentrations were higher (P < 0.05) and remained elevated longer after ovulation induction with hCG. In Study 3, gonadotropin-stimulated queens (n = 7) were artificially inseminated and ovariohysterectomized 160 h after hCG. Ancillary follicles and/or corpora lutea were observed in 5 of 6 (83%) ovulating queens. Both fecal E and number of unovulated follicles observed at ovariohysterectomy were negatively correlated with the percentage of embryos recovered from the uterus (r = -0.91 and r = -0.87, respectively; P < 0.05). In summary, exogenous gonadotropin administration causes an abnormal endocrine environment in domestic cats, likely due to ancillary follicle development. The sustained elevations in estradiol appear to impair oviductal transport of embryos, possibly leading to the reduced fertility typically observed in cats subjected to gonadotropin stimulation and AI. (C) 2000 by Elsevier Science Inc. C1 Smithsonian Inst, Conservat & Res Ctr, Natl Zool Pk, Front Royal, VA USA. George Mason Univ, Fairfax, VA 22030 USA. Cincinnati Zoo & Bot Garden, Ctr Res Endangered Wildlife, Cincinnati, OH USA. RP Graham, LH (reprint author), Disneys Anim Kingdom, POB 10000, Lake Buena Vista, FL 32830 USA. NR 51 TC 41 Z9 43 U1 3 U2 5 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0093-691X J9 THERIOGENOLOGY JI Theriogenology PD OCT 15 PY 2000 VL 54 IS 7 BP 1117 EP 1131 DI 10.1016/S0093-691X(00)00420-9 PG 15 WC Reproductive Biology; Veterinary Sciences SC Reproductive Biology; Veterinary Sciences GA 380XP UT WOS:000165729600013 PM 11131330 ER PT J AU West, SA Herre, EA Sheldon, BC AF West, SA Herre, EA Sheldon, BC TI The benefits of allocating sex SO SCIENCE LA English DT Editorial Material ID SELECTION THEORY; KIN SELECTION; FIG WASPS; RATIOS; ANT; STRATEGIES C1 Univ Edinburgh, Inst Cell Anim & Populat Biol, Edinburgh EH9 3JT, Midlothian, Scotland. Smithsonian Trop Res Inst, Balboa, Panama. Univ Oxford, Dept Zool, Oxford OX1 3PS, England. RP West, SA (reprint author), Univ Edinburgh, Inst Cell Anim & Populat Biol, W Mains Rd, Edinburgh EH9 3JT, Midlothian, Scotland. RI Sheldon, Ben/A-8056-2010; West, Stuart/M-3608-2014 OI Sheldon, Ben/0000-0002-5240-7828; West, Stuart/0000-0003-2152-3153 NR 36 TC 96 Z9 99 U1 3 U2 32 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD OCT 13 PY 2000 VL 290 IS 5490 BP 288 EP 290 DI 10.1126/science.290.5490.288 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 363CW UT WOS:000089818100033 PM 11183376 ER PT J AU Perna, R Di Matteo, T AF Perna, R Di Matteo, T TI Synchrotron emission from hot accretion flows and the cosmic microwave background anisotropy SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; cosmic microwave background : anisotropies ID ADVECTION-DOMINATED ACCRETION; SPECTRUM RADIO-SOURCES; BLACK-HOLES; GALAXY; LUMINOSITY; CONSTRAINTS; GHZ AB Current estimates of number counts of radio sources in the frequency range in which the most sensitive cosmic microwave background (CMB) experiments are carried out significantly underrepresent sources with strongly inverted spectra. Hot accretion flows around supermassive black holes in the nuclei of nearby galaxies are expected to produce inverted radio spectra by thermal synchrotron emission. We calculate the temperature fluctuations and power spectra of these sources in the Planck Surveyor 30 GHz energy channel, where their emission is expected to peak. We find that their potential contribution is generally comparable to the instrumental noise, and approaches the CMB anisotropy level at small angular scales. Forthcoming missions, which will provide a large statistical sample of inverted-spectra sources, will be crucial for determining the distribution of hot accretion flows in nearby quiescent galactic nuclei. Detection of these sources in different frequency channels will help constrain their spectral characteristics, and hence their physical properties. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NR 36 TC 9 Z9 9 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2000 VL 542 IS 1 BP 68 EP 73 DI 10.1086/309544 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 365ME UT WOS:000089954400008 ER PT J AU Keeton, CR Falco, EE Impey, CD Kochanek, CS Lehar, J McLeod, BA Rix, HW Munoz, JA Peng, CY AF Keeton, CR Falco, EE Impey, CD Kochanek, CS Lehar, J McLeod, BA Rix, HW Munoz, JA Peng, CY TI The host galaxy of the lensed quasar Q0957+561 SO ASTROPHYSICAL JOURNAL LA English DT Article DE distance scale; galaxies : individual (Q0957+561); gravitational lensing; quasars : individual (Q0957+561) ID LARGE-SCALE STRUCTURE; GRAVITATIONAL LENS; HUBBLE-CONSTANT; TIME-DELAY; SYSTEM 0957+561; VLBI OBSERVATIONS; GLOBAL VALUE; DARK-MATTER; PG-1115+080; MODELS AB Infrared images of the Q0957 + 561 gravitational lens obtained with the Hubble Space Telescope show two large (similar to5 ") lensed images of the z(s) = 1.41 quasar host galaxy. Parts of the host galaxy are doubly imaged, Like the quasar, while other parts are quadruply imaged. The distortions of the host galaxy offer the best probe yet of the global structure of the lensing potential, which is essential for determining the Hubble constant from the measured time delay. The distortions are inconsistent with the predictions of previously published lens models, which invalidates those models and their implications for H(0). New models show that the distortions finally break the long-standing degeneracy between the shape of the lens galaxy and the tidal shear contributed by the cluster containing the lens galaxy. The shape of the lens galaxy's mass distribution must be remarkably similar to the shape of its luminosity distribution, and most models that produce reasonable values for the Hubble constant roughly match the observed ellipticity gradient and isophote twist of the lens galaxy. In addition, the cluster must be nonspherical and produce a relatively small tidal shear. Although there are still degeneracies in the lens models that lead to a 25% uncertainty in the derived value of the Hubble constant, there are also strong prospects for new observations to further improve the constraints and reduce the uncertainties. C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Max Planck Inst Astron, D-69117 Heidelberg, Germany. Inst Astrofis Canarias, E-38200 San Cristobal la Laguna, Tenerife, Spain. RP Keeton, CR (reprint author), Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. EM ckeeton@arizona.edu; efalco@cfa.harvard.edu; cimpey@arizona.edu; ckochanek@cfa.harvard.edu; jlehar@cfa.harvard.edu; bmcleod@cfa.harvard.edu; rix@mpia-hd.mpg.de; jmunoz@cfa.harvard.edu; cypas@arizona.edu NR 64 TC 54 Z9 54 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2000 VL 542 IS 1 BP 74 EP 93 DI 10.1086/309517 PN 1 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 365ME UT WOS:000089954400009 ER PT J AU Peterson, BM McHardy, IM Wilkes, BJ Berlind, P Bertram, R Calkins, M Collier, SJ Huchra, JP Mathur, S Papadakis, I Peters, J Pogge, RW Romano, P Tokarz, S Uttley, P Vestergaard, M Wagner, RM AF Peterson, BM McHardy, IM Wilkes, BJ Berlind, P Bertram, R Calkins, M Collier, SJ Huchra, JP Mathur, S Papadakis, I Peters, J Pogge, RW Romano, P Tokarz, S Uttley, P Vestergaard, M Wagner, RM TI X-ray and optical variability in NGC 4051 and the nature of narrow-line Seyfert 1 galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : individual (NGC 4051); galaxies : nuclei; galaxies : Seyfert; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; REGION SIZES; BLACK-HOLES; NGC-4051; QUASARS; SPECTRA; MODEL; DISKS AB We report on the results of a three-year program of coordinated X-ray and optical monitoring of the narrow-line Seyfert 1 galaxy NGC 4051. The rapid continuum variations observed in the X-ray spectra are not detected in the optical, although the time-averaged X-ray and optical continuum fluxes are well correlated. Variations in the flux of the broad H beta line are found to lag behind the optical continuum variations by 6 days (with an uncertainty of 2-3 days), and combining this with the line width yields a virial mass estimate of similar to1.1 x 10(6) M(.), at the very low end of the distribution of active galactic nucleus masses measured by line reverberation. Strong variability of He II lambda 4686 is also detected, and the response time measured is similar to that of H beta but with a much larger uncertainty. The He II lambda 4686 line is almost 5 times broader than H beta, and it is strongly blueward asymmetric, as are the high-ionization UV lines recorded in archival spectra of NGC 4051. The data are consistent with the Balmer lines arising in a low-to-moderate-inclination disklike configuration and the high-ionization lines arising in an outflowing wind, of which we observe preferentially the near side. Previous observations of the narrow-line region morphology of this source suggest that the system is inclined by similar to 50 degrees, and if this is applicable to the broad H beta -emitting region, a central mass of similar to1.4 x 10(6) M(.) can be inferred. During the third year of monitoring, both the X-ray continuum and the He II lambda 4686 line went into extremely low states, although the optical continuum and the H beta broad line were both still present and variable. We suggest that the inner part of the accretion disk may have gone into an advection-dominated state, yielding little radiation from the hotter inner disk. C1 Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. Univ Southampton, Dept Phys & Astron, Southampton, Hants, England. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Univ Crete, Dept Phys, Iraklion 71003, Crete, Greece. RP Peterson, BM (reprint author), Ohio State Univ, Dept Astron, 140 W 18th Ave, Columbus, OH 43210 USA. EM peterson@astronomy.ohio-state.edu; imh@astro.soton.ac.uk; belinda@cfa.harvard.edu; pberlind@cfa.harvard.edu; rayb@as.arizona.edu; mcalkins@cfa.harvard.edu; stefan@astronomy.ohio-state.edu; huchra@cfa.harvard.edu; smita@astronomy.ohio-state.edu; jhep@physics.uoc.gr; pogge@astronomy.ohio-state.edu; promano@astronomy.ohio-state.edu; stokarz@cfa.harvard.edu; pu@astro.soton.ac.uk; vester@astronomy.ohio-state.edu; rmw@as.arizona.edu RI Papadakis, Iossif/C-3235-2011; Vestergaard, Marianne/M-5247-2014; OI Vestergaard, Marianne/0000-0001-9191-9837; Romano, Patrizia/0000-0003-0258-7469; Wilkes, Belinda/0000-0003-1809-2364 NR 51 TC 147 Z9 147 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2000 VL 542 IS 1 BP 161 EP 174 DI 10.1086/309518 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 365ME UT WOS:000089954400016 ER PT J AU Hughes, JP Slane, PO Plucinsky, PP AF Hughes, JP Slane, PO Plucinsky, PP TI Discovery of X-ray emission from G328.4+0.2, a Crab-like supernova remnant SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (G328.4+0.2, MSH 15-57); pulsars : general; supernova remnants; X-rays : ISM ID LARGE-MAGELLANIC-CLOUD; ASCA OBSERVATIONS; GALACTIC PLANE; CO SURVEY; CATALOG; DISTANCES; PULSARS; N157B; ROSAT AB G328.4+0.2 is a moderately small (5' x 5') Galactic radio supernova remnant (SNR) at a distance of at least 17 kpc that has been long suggested to be Crab-like. Here we report on the detection with ASCA of the X-ray emission from the SNR. The X-ray source is faint with an observed flux of (6.0 +/- 0.8) x 10(-13) ergs s(-1) cm(-2) over the 2-10 keV band. The emission is heavily cut off at low energies and no flux is detected below 2 keV. Spectral analysis confirms that the column density to the source is indeed large, N-H similar to 10(23) atoms cm(-2), and consistent with the total column density of hydrogen through the Galaxy at this position. Good fits to the spectrum can be obtained for either thermal plasma or nonthermal power-law models, although the lack of detected Line emission as well as other evidence argues against the former interpretation. The power-law index we find, alpha (P) = 2.9(-0.8)(+0.9), is consistent with other Crab-like SNRs. In the radio band, G328.4+0.2 is nearly as luminous as the Crab Nebula, yet in the X-ray band, it is some 70 times fainter. Nevertheless, its inferred soft X-ray band luminosity is greater than all but the brightest pulsar-powered synchrotron nebulae and implies that G328.4+0.2 contains a rapidly spinning, as yet undetected, pulsar that is losing energy at a rate of similar to 10(38) ergs s(-1). C1 Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08854 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CEA Saclay, Serv Astrophys, F-91191 Gif Sur Yvette, France. RP Hughes, JP (reprint author), Rutgers State Univ, Dept Phys & Astron, 136 Frelinghuysen Rd, Piscataway, NJ 08854 USA. NR 28 TC 3 Z9 3 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2000 VL 542 IS 1 BP 386 EP 391 DI 10.1086/309532 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 365ME UT WOS:000089954400036 ER PT J AU Janiuk, A Czerny, B Siemiginowska, A AF Janiuk, A Czerny, B Siemiginowska, A TI Radiation pressure instability as a variability mechanism in the microquasar GRS 1915+105 SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; binaries : close; black hole physics; instabilities; stars : individual (GRS 1915+105) ID SLIM ACCRETION DISKS; BLACK-HOLES; BINARY-SYSTEMS; GRS-1915+105; MODEL AB The physical mechanism responsible for the high viscosity in accretion disks is still under debate. The parameterization of the viscous stress as alphaP proved to be a successful representation of this mechanism in the outer parts of the disk, explaining the dwarf novae and X-ray novae outbursts as being due to ionization instability. We show that this parameterization can also be adopted in the innermost part of the disk where the adoption of the or-viscosity law implies the presence of the instability in the radiation pressure-dominated region. We study the time evolution of such disks. We show that the time-dependent behavior of GRS 1915+105 can be well reproduced if the or-viscosity disk model is calculated accurately (with proper numerical coefficients in vertically averaged equations and with advection included) and if the model is supplemented with (1) a moderate corona dissipating 50% of energy and (2) a jet carrying a luminosity-dependent fraction of energy. These necessary modifications in the form of the presence of a, corona and a jet are well justified observationally. The model predicts outbursts at a luminosity larger than 0.16(M) over dot(Edd), as required, and correct outburst timescales and amplitudes, including the effect of an increasing outburst timescale with mean luminosity. This result strongly suggests also that the or-viscosity law is a good description of the actual mechanism responsible for angular momentum transfer in the innermost, radiation pressure-dominated part of the disk around a black hole. C1 Nicolas Copernicus Astron Ctr, PL-00716 Warsaw, Poland. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Janiuk, A (reprint author), Nicolas Copernicus Astron Ctr, Bartycka 18, PL-00716 Warsaw, Poland. RI Czerny, Bozena/A-2363-2015 OI Czerny, Bozena/0000-0001-5848-4333 NR 24 TC 31 Z9 31 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2000 VL 542 IS 1 BP L33 EP L36 DI 10.1086/312911 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 365MF UT WOS:000089954500009 ER PT J AU Kaaret, P Cusumano, G Sacco, B AF Kaaret, P Cusumano, G Sacco, B TI X-ray timing of the 34 millisecond binary pulsar SAX J0635+0533 SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : observations; pulsars : general; stars : individual (2EG J0635+0521; SAX J0635+0533); stars : neutron ID STARS AB Modulations detected in the observed spin period of the 34 ms X-ray pulsar SAX J0635+0533 show that the pulsar is in a binary system with a period of 11.2 +/- 0.5 days, a projected orbital semimajor axis a sin i = 83 +/- 11 It-s, a mass function in the range of 3.4-7.8 M-circle dot, and an orbital eccentricity of 0.29 +/- 0.09. A combination of observations spanning 2 yr places a lower bound on the intrinsic period derivative of the pulsar of 3.8 x 10(-13). The period derivative implies a high torque on the neutron star that would require a very high mass accretion rate, in excess of 6 x 10(-7) M-circle dot yr(-1), if produced via accretion. The torque and X-ray luminosity are both within the range typical of young, rotation-powered pulsars. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CNR, Ist Fis Cosm Applicaz Informat, I-90146 Palermo, Italy. RP Kaaret, P (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 13 TC 18 Z9 19 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2000 VL 542 IS 1 BP L41 EP L43 DI 10.1086/312918 PN 2 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 365MF UT WOS:000089954500011 ER PT J AU Michael, E McCray, R Pun, CSJ Garnavich, P Challis, P Kirshner, RP Raymond, J Borkowski, K Chevalier, R Filippenko, AV Fransson, C Lundqvist, P Panagia, N Phillips, MM Sonneborn, G Suntzeff, NB Wang, LF Wheeler, JC AF Michael, E McCray, R Pun, CSJ Garnavich, P Challis, P Kirshner, RP Raymond, J Borkowski, K Chevalier, R Filippenko, AV Fransson, C Lundqvist, P Panagia, N Phillips, MM Sonneborn, G Suntzeff, NB Wang, LF Wheeler, JC TI Hubble Space Telescope spectroscopy of spot 1 on the circumstellar ring of SN 1987A SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; shock waves; supernova remnants; supernovae : individual (SN 1987A) ID MAGELLANIC CLOUDS; RADIATIVE SHOCKS; LINE EMISSION; SN-1987A; PROGENITOR; ABUNDANCES; WAVES AB We present ultraviolet and optical spectra of the first bright spot (P.A. = 29 degrees) on SN 1987A's equatorial circumstellar ring taken with the Space Telescope Imaging Spectrograph. We interpret this spot as the emission produced by radiative shocks that occur where the supernova blast wave strikes an inward protrusion of the ring. The observed line widths and intensity ratios indicate the presence of radiative shocks with velocities ranging from 100 to 250 km s(-1) entering dense (greater than or similar to 10(4) cm(-3)) gas. These observations, and future observations of the development of the spectra and line profiles, provide a unique opportunity to study the hydrodynamics of radiative shocks. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NASA, Goddard Space Flight Ctr, Lab Astron & Space Phys, Greenbelt, MD 20771 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. Univ Virginia, Dept Astron, Charlottesville, VA 22903 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Stockholm Observ, SE-13336 Saltsjobaden, Sweden. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Observ Carnegie Inst Washington, Observ Las Campanas, La Serena, Chile. Natl Opt Astron Observ, Cerro Tololo Interamer Observ, La Serena, Chile. Univ Texas, Dept Astron, Austin, TX 78712 USA. RP Michael, E (reprint author), Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. EM michaele@colorado.edu NR 24 TC 37 Z9 37 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2000 VL 542 IS 1 BP L53 EP L56 DI 10.1086/312924 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 365MF UT WOS:000089954500014 ER PT J AU Wood, K Wolk, SJ Stanek, KZ Leussis, G Stassun, K Wolff, M Whitney, B AF Wood, K Wolk, SJ Stanek, KZ Leussis, G Stassun, K Wolff, M Whitney, B TI Optical variability of the T Tauri star HH30IRS SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; radiative transfer; stars : individual (HH 30); stars : pre-main-sequence; stars : rotation; stars : spots ID MAIN-SEQUENCE STARS; MAGNETOCENTRIFUGALLY DRIVEN FLOWS; DETACHED ECLIPSING BINARIES; MAGNETIC NEUTRON STARS; YOUNG STELLAR OBJECTS; ORION-NEBULA-CLUSTER; PHOTOPOLARIMETRIC VARIABILITY; ROTATION PERIODS; UBVRI PHOTOMETRY; DIRECT DISTANCES AB We report results of VRI photometric monitoring of the T Tauri star plus disk system HH 38 IRS. We find that HH 30 IRS is highly variable over timescales of a few days with DeltaV similar to 1.5 mag, DeltaI similar to 1.1 mag. Furthermore, we find hints of periodicity with periodograms indicating possible periods of 11.6 and 19.8 days. The VRI photometry is available through the ANONYMOUS I;TP service. We model the variability with Monte Carlo radiation transfer simulations for a spotted star plus disk system and find that the large variability is best reproduced with a single hot spot and circumstellar grains that are larger than typical interstellar grains. The apparent existence of a single hot spot and the need for larger, more forward-throwing grains is consistent with previous modeling of Hubble Space Telescope imagery. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Wisconsin, Dept Astron, Madison, WI 53706 USA. Space Sci Inst, Boulder, CO 80303 USA. RP Wood, K (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 42 TC 14 Z9 14 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2000 VL 542 IS 1 BP L21 EP L24 DI 10.1086/312920 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 365MF UT WOS:000089954500006 ER PT J AU Hershler, R Sada, DW AF Hershler, R Sada, DW TI A new species of hydrobiid snail of the genus Pyrgulopsis from northwestern Nevada SO VELIGER LA English DT Article ID WESTERN UNITED-STATES; GREAT-BASIN; RISSOOIDEA; GASTROPODA AB Pyrgulopsis bruesi new species, from northwest Nevada, differs from closely similar P. augustae on the basis of its higher-spired shell, larger penial filament, and more ventrally positioned seminal receptacle. This species is endemic to a thermal spring area in a small basin which was inundated by pluvial Lake Lahontan. C1 Smithsonian Inst, Natl Museum Amer Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. Desert Res Inst, Reno, NV 89512 USA. Univ Nevada, Biol Resources Ctr, Reno, NV 89557 USA. RP Hershler, R (reprint author), Smithsonian Inst, Natl Museum Amer Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. NR 26 TC 8 Z9 8 U1 0 U2 0 PU CALIF MALACOZOOLOGICAL SOC INC PI SANTA BARBARA PA SANTA BARBARA MUSEUM NATURAL HISTORY, 2559 PUESTA DEL SOL RD, SANTA BARBARA, CA 93105 USA SN 0042-3211 J9 VELIGER JI Veliger PD OCT 2 PY 2000 VL 43 IS 4 BP 367 EP 375 PG 9 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 360ZW UT WOS:000089698100010 ER PT J AU Price, T Lovette, IJ Bermingham, E Gibbs, HL Richman, AD AF Price, T Lovette, IJ Bermingham, E Gibbs, HL Richman, AD TI The imprint of history on communities of North American and Asian warblers SO AMERICAN NATURALIST LA English DT Article DE ancestral reconstruction; community convergence; Dendroica; Phylloscopus; phylogeny; sexual selection ID WORLD LEAF WARBLERS; SEXUAL SELECTION; PASSERINE BIRDS; GENUS PHYLLOSCOPUS; ADAPTIVE RADIATION; MOLECULAR CLOCK; BODY-SIZE; EVOLUTION; PHYLOGENIES; HABITAT AB The ecology of the component species of an adaptive radiation is likely to be influenced by the form of the founding ancestor to the radiation, its timing, and rates of speciation and extinction. These historical features complement environmental selection pressures. They imply that, if the history of the species' radiations are very different, ecological communities are unlikely to be completely convergent even when placed in identical environments. We compare the adaptive radiation of the Dendroica warblers of North America with that of the Phylloscopus warblers of Asia. We consider the ecology of the species in two localities where species' diversity is very high (New Hampshire, U.S.A., and Kashmir, India, respectively) and contrast the history of the two radiations on the basis of a molecular (mitochondrial cytochrome b) phylogeny. By comparison with the Phylloscopus, the Dendroica are on average larger and morphologically more similar to one another. Although there is some similarity between the Dendroica and Phylloscopus communities, they differ in foraging behavior and in associations of morphology with ecological variables. The Dendroica likely reflect an early Pliocene radiation and are two to four times younger than the Phylloscopus. They probably had a colorful sexually dichromatic ancestor, implicating sexual selection in the production of the many ecologically similar species. The Phylloscopus are much older and probably had a drab, monomorphic ancestor. Given the difference in ages of the two radiations, it is plausible that the dose species' packing of the Dendroica warblers is a transient phenomenon. If this is the case, community structure evolves on the timescales of millions of years. Differences in ancestry and timing of the species' radiations can be related to the different biogeography of the two regions. This implies that the historical imprint on adaptive radiations could be predicted on the basis of the attributes of ancestors and biogeographical context. C1 Univ Calif San Diego, Dept Biol, La Jolla, CA 92093 USA. Smithsonian Trop Res Inst, Balboa, Panama. Univ Penn, Dept Biol, Philadelphia, PA 19104 USA. McMaster Univ, Dept Biol, Hamilton, ON L8S 4K1, Canada. Montana State Univ, Dept Biol, Bozeman, MT 59717 USA. RP Price, T (reprint author), Univ Calif San Diego, Dept Biol, La Jolla, CA 92093 USA. EM tprice@ucsd.edu RI Lovette, Irby/P-3477-2014 NR 59 TC 67 Z9 67 U1 0 U2 12 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0003-0147 J9 AM NAT JI Am. Nat. PD OCT PY 2000 VL 156 IS 4 BP 354 EP 367 DI 10.1086/303397 PG 14 WC Ecology; Evolutionary Biology SC Environmental Sciences & Ecology; Evolutionary Biology GA 355VA UT WOS:000089408200003 ER PT J AU Warkentin, KM AF Warkentin, KM TI Wasp predation and wasp-induced hatching of red-eyed treefrog eggs SO ANIMAL BEHAVIOUR LA English DT Article ID SALAMANDER EGGS; HYMENOPTERA; VESPIDAE; RISK; EMBRYOS; LARVAE; TASTY; SIZE; AGE AB Eggs often suffer high levels of predation and, compared with older animals, embryos have few options available for antipredator defence. None the less, hatchlings can escape from many predators to which eggs are vulnerable. I studied early hatching as an antipredator defence of red-eyed treefrog embryos, Agalychnis callidryas, in response to egg predation by social wasps (Polybia rejecta). Red-eyed treefrogs attach their eggs to vegetation overhanging;water, where they are exposed to arboreal and aerial predators. Wasps attacked half the egg clutches and killed almost a quarter of the eggs I monitored at a natural breeding site in Panama. Hatching tadpoles fall into the water, where they face aquatic predators. As predicted from improved survival of older hatchlings with aquatic predators, most undisturbed eggs hatched relatively late. However, many younger embryos directly attacked by wasps hatched immediately. Embryos attacked by wasps hatched as much as a third younger than the peak undisturbed hatching age, and most hatching embryos escaped. Thus hatching is an effective defence against wasp predation, and plasticity in hatching stage allows embryos to balance risks from stage-specific egg and larval predators. Wasp-induced hatching is behaviourally similar to the snake-induced hatching previously described in A. callidryas, but occurs in fewer eggs at a time, congruent with the scale of the risk. Individual embryos hatch in response to wasps, which take single eggs, whereas whole clutches hatch in response to snakes, which consume entire clutches. Embryos of A. callidryas thus respond appropriately to graded variation in mortality risks. (C) 2000 The Association for the Study of Animal Behaviour. C1 Smithsonian Trop Res Inst, Balboa, Panama. RP Warkentin, KM (reprint author), Univ Kentucky, Sch Biol Sci, Lexington, KY 40506 USA. NR 29 TC 101 Z9 107 U1 3 U2 15 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0003-3472 J9 ANIM BEHAV JI Anim. Behav. PD OCT PY 2000 VL 60 BP 503 EP 510 DI 10.1006/anbe.2000.1508 PN 4 PG 8 WC Behavioral Sciences; Zoology SC Behavioral Sciences; Zoology GA 368DA UT WOS:000090101400011 ER PT J AU Helbsing, S Riederer, M Zotz, G AF Helbsing, S Riederer, M Zotz, G TI Cuticles of vascular epiphytes: Efficient barriers for water loss after stomatal closure? SO ANNALS OF BOTANY LA English DT Article DE Barro Colorado Island; cuticular transpiration; epiphyte; plant water relations; transport barrier ID CUTICULAR MEMBRANES; PLANT CUTICLES; PERMEABILITY; TEMPERATURE; ORCHID AB Water permeabilities of astomatous, isolated cuticular membranes of 15 vascular epiphyte species (families: Araceae, Orchidaceae and Piperaceae) from the moist lowland forest of Barro Colorado Nature Monument, Panama, were investigated. Permeances determined at 30 degrees C ranged from 0.46 x 10(-6) m s(-1) (Aspasia principissa (Rchb. f.) R.E. Schult.) to 6.07 x 10(-6) m s(-1) (Polystachya foliosa (Hook.) Rchb. f). Comparison of these data with permeances of plants from other habitats corroborates the notion that cuticular properties reflect the climatic demands of the growing sites. The studied group of vascular epiphytes, living in a very drought-prone habitat, showed the lowest cuticular permeances to water recorded to date. (C) 2000 Annals of Botany Company. C1 Univ Wurzburg, Lehrstuhl Bot 2, D-97082 Wurzburg, Germany. Smithsonian Trop Res Inst, Balboa, Panama. RP Zotz, G (reprint author), Univ Wurzburg, Lehrstuhl Bot 2, D-97082 Wurzburg, Germany. RI Riederer, Markus/B-5540-2008 OI Riederer, Markus/0000-0001-7081-1456 NR 22 TC 21 Z9 29 U1 0 U2 13 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0305-7364 J9 ANN BOT-LONDON JI Ann. Bot. PD OCT PY 2000 VL 86 IS 4 BP 765 EP 769 DI 10.1006/anbo.2000.1239 PG 5 WC Plant Sciences SC Plant Sciences GA 359EY UT WOS:000089599600008 ER PT J AU Virani, SN De Robertis, MM VanDalfsen, ML AF Virani, SN De Robertis, MM VanDalfsen, ML TI A CCD study of the environment of Seyfert galaxies. III. Host galaxies and the nearby environments SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : evolution; galaxies : interactions; galaxies : Seyfert ID NUCLEAR ACTIVITY; DECONVOLUTION; COMPONENTS; STELLAR; DISKS; BARS AB A technique is described that permits the robust decomposition of the bulge and disk components of a sample of Seyfert galaxies, as well as a (control) sample of nonactive galaxies matched to the Seyferts in the distributions of redshift, luminosity, and morphological classification. The structural parameters of the host galaxies in both samples are measured. No statistically significant differences at greater than the 95% level are found in these parameters according to a Kolmogorov-Smirnov test. "Companion galaxies"-defined as any galaxy within a projected separation of 200 h(-1) kpc from the center of the host-are identified and their basic properties measured. A comparison between the active and control samples in the distributions of apparent R magnitude, absolute R magnitude (assuming the companions are at the distance of the host), projected separation from the host, position angle relative to the host, magnitude difference between the companion and host, and strength of the tidal parameter shows no statistically significant differences. Similarly, no statistically significant differences are found between the control and active sample host galaxies in terms of light asymmetries-bars, rings, isophotal twisting, etc. The implications for a model in which interactions and mergers are responsible for inciting activity in galactic nuclei are discussed briefly. C1 York Univ, Dept Phys & Astron, N York, ON M3J 1P3, Canada. McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. RP Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM svirani@cfa.harvard.edu; mmdr@yorku.ca; vandalfs@physics.mcmaster.ca NR 28 TC 33 Z9 33 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 EI 1538-3881 J9 ASTRON J JI Astron. J. PD OCT PY 2000 VL 120 IS 4 BP 1739 EP 1749 DI 10.1086/301586 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 364GQ UT WOS:000089884400013 ER PT J AU Sankrit, R Blair, WP Raymond, JC Long, KS AF Sankrit, R Blair, WP Raymond, JC Long, KS TI Hubble Space Telescope STIS observations of the Cygnus Loop: Spatial structure of a nonradiative shock SO ASTRONOMICAL JOURNAL LA English DT Article DE ISM : individual (Cygnus Loop); reflection nebulae; shock waves; supernova remnants ID HOPKINS-ULTRAVIOLET-TELESCOPE; EMISSION; WAVES; SPECTRUM; FILAMENT; LINE AB We present a spatially resolved ultraviolet spectrum of a nonradiative shock front in the Cygnus Loop, obtained with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. The spectrum covers the wavelength range 1118-1716 Angstrom with an effective spectral resolution of similar to 12 Angstrom. The 0." 1 spatial resolution of these data provides a huge improvement over earlier ultraviolet spectra, allowing us to study the spatial distribution of high-ionization line emissions directly behind the shock front. We are able to isolate individual shock features in our spectrum by comparing the STIS spectrum with a Wide Field Planetary Camera 2 H alpha image of the region. Isolating the brightest shock tangency, we identify lines of N v lambda 1240, C Iv lambda 1549, He II lambda 1640, O v lambda 1371, O IV], Si Iv lambda 1400, and N IV] lambda 1486, as well as the hydrogen two-photon continuum. The N v line peaks similar to 0." 3 behind the C Iv and He II emission and is spatially broader than the other emissions. Also, the observed line ratios of C Iv and He II to N v are higher in our bright-shock spectrum than in previous observations of the same filament obtained through much larger apertures land little or no spatial resolution), indicating that there must be a more widely distributed component of the N v emission. We calculate shock models and show that the observed separation between the C Iv and N v emission zones and observed line intensities constrain the combinations of shock velocity and preshock density that are allowed. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. RP Sankrit, R (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA. NR 19 TC 18 Z9 18 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD OCT PY 2000 VL 120 IS 4 BP 1925 EP 1932 DI 10.1086/301578 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 364GQ UT WOS:000089884400028 ER PT J AU Vignali, C Comastri, A Nicastro, F Matt, G Fiore, F Palumbo, GGC AF Vignali, C Comastri, A Nicastro, F Matt, G Fiore, F Palumbo, GGC TI On the peculiar X-ray properties of the bright nearby radio-quiet quasar PDS 456 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : nuclei; galaxies : quasars : individual : PDS 456; X-rays : galaxies ID ASTRONOMY SATELLITE; LUMINOUS QUASAR; ON-BOARD; SPECTRA; ASCA; GALAXIES; EXOSAT; GINGA; GAS AB BeppoSAX and ASCA observations of the nearby (z = 0.184), high-luminosity, radio-quiet quasar PDS 456 are presented. The X-ray spectrum is characterized by a prominent ionized edge at 8-9 keV (originally discovered by RXTE, Reeves et al. 2000) and by a soft excess below 1.5 keV. The lack of any significant iron K alpha emission line suggests for the edge an origin from line-of-sight material rather than from reflection from a highly ionized accretion disc. The hard X-ray continuum is indeed well modelled by transmission through a highly-ionized medium with a large column density (N-Hwarm similar to 4.5 x 10(24) cm(-2)) plus an additional cold absorber with a lower column density (N-Hcold similar to 2.7 x 10(22) cm(-2)). C1 Univ Bologna, Dipartimento Astron, I-40127 Bologna, Italy. Osservatorio Astron Bologna, I-40127 Bologna, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Osservatorio Astron Roma, I-00044 Monteporzio, Italy. Univ Studi Roma Tre, Dipartimento Fis, I-00146 Rome, Italy. BeppoSAX Sci Data Ctr, I-00131 Rome, Italy. RP Vignali, C (reprint author), Univ Bologna, Dipartimento Astron, Via Ranzani 1, I-40127 Bologna, Italy. EM vignali@kennet.bo.astro.it RI Vignali, Cristian/J-4974-2012; Comastri, Andrea/O-9543-2015; OI Vignali, Cristian/0000-0002-8853-9611; Comastri, Andrea/0000-0003-3451-9970; Nicastro, Fabrizio/0000-0002-6896-1364; Fiore, Fabrizio/0000-0002-4031-4157 NR 41 TC 4 Z9 4 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD OCT PY 2000 VL 362 IS 1 BP 69 EP 74 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 375CR UT WOS:000165382400007 ER PT J AU Polletta, M Courvoisier, TJL Hooper, EJ Wilkes, BJ AF Polletta, M Courvoisier, TJL Hooper, EJ Wilkes, BJ TI The far-infrared emission of radio loud and radio quiet quasars SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : quasars : general; infrared : galaxies; radio continuum : galaxies ID ACTIVE GALACTIC NUCLEI; SPECTRAL ENERGY-DISTRIBUTION; OBSCURING DUST TORI; X-RAY-PROPERTIES; HOST GALAXIES; SEYFERT-1 GALAXIES; OPTICAL-PROPERTIES; VLA OBSERVATIONS; THICK TORI; MILLIMETER AB Continuum observations at radio, millimetre, infrared and soft X-ray energies are presented for a sample of 22 quasars, consisting of flat and steep spectrum radio loud, radio intermediate and radio quiet objects. The primary observational distinctions, among the different kinds of quasars in the radio and IR energy domains are studied using large observational datasets provided by ISOPHOT on board the Infrared Space Observatory, by the IRAM interferometer, by the sub-millimetre array SCUBA on JCMT, and by the European Southern Observatory (ESO) facilities IRAC1 on the 2.2 m telescope and SEST. The spectral energy distributions of all quasars from radio to IR energies are analyzed and modeled with non-thermal and thermal spectral. components. The dominant mechanism emitting in the far/mid-IR is thermal dust emission in all quasars, with the exception of flat spectrum radio loud quasars for which the presence of thermal IR emission remains rather uncertain, since it is difficult to separate it from the bright non-thermal component. The dust is predominantly heated by the optical/ultraviolet radiation emitted from the external components of the AGN. A starburst contributes to the IR emission at different levels, but always less than the AGN (less than or equal to 27%). The distribution of temperatures, sizes, masses, and luminosities of the emitting dust are independent of the quasar type. C1 Observ Geneva, CH-1290 Sauverny, Switzerland. Integral Sci Data Ctr, CH-1290 Versoix, Switzerland. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Polletta, M (reprint author), Observ Geneva, Ch Maillettes 11, CH-1290 Sauverny, Switzerland. EM Maria.Polletta@obs.unige.ch OI Polletta, Maria del Carmen/0000-0001-7411-5386 NR 91 TC 52 Z9 52 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD OCT PY 2000 VL 362 IS 1 BP 75 EP 96 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 375CR UT WOS:000165382400008 ER PT J AU van den Ancker, ME The, PS de Winter, D AF van den Ancker, ME The, PS de Winter, D TI The central part of the young open cluster NGC 6383 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : circumstellar matter; stars : pre-main sequence; ISM : dust, extinction; ISM : HII regions; Galaxy : open clusters and associations : individual : NGC 6383 ID STARS AB The spectral and extinction properties of 14 pre-main sequence candidates in the central part of the very young open cluster NGC 6383 were investigated. None of these stars shows evidence for anomalous circumstellar extinction. However, six out of 14 programme stars do show an infrared excess, indicative of the presence of circumstellar dust, heated up by the central star. One of these stars (number 4), also shows H alpha in emission and shows some indications for the presence of circumstellar eas in its spectrum, and might therefore be a newly identified Herbig Ae star. C1 Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. TNO, TPD, NL-2600 AD Delft, Netherlands. RP van den Ancker, ME (reprint author), Univ Amsterdam, Astron Inst Anton Pannekoek, Kruislaan 403, NL-1098 SJ Amsterdam, Netherlands. EM mario@astro.uva.nl NR 18 TC 8 Z9 8 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD OCT PY 2000 VL 362 IS 2 BP 580 EP 584 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 376JU UT WOS:000165455100022 ER PT J AU Giommi, P Perri, M Fiore, F AF Giommi, P Perri, M Fiore, F TI The BeppoSAX 2-10 keV survey SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE surveys; cosmology : observations; X-rays : galaxies; X-rays : general ID ACTIVE GALACTIC NUCLEI; ROSAT DEEP SURVEY; X-RAY SOURCES; BL-LACERTAE OBJECTS; LUMINOSITY FUNCTION; OPTICAL-IDENTIFICATION; BACKGROUND SPECTRUM; ASCA OBSERVATIONS; QUASAR CATALOG; LOCKMAN FIELD AB We present the results of a 2-10 keV BeppoSAX survey based on 140 high galactic latitude MECS fields, 12 of which are deep exposures of "blank" parts of the sky. The limiting sensitivity is 5 x 10(-14) erg cm(-2) s(-1) where about 25% of the Cosmic X-ray Background (CXB) is resolved into discrete sources. The logN-logS function, built with a statistically complete sample of 177 sources, is steep and in good agreement with the counts derived from ASCA surveys. A CXB fluctuation analysis allowed us to probe the logN-logS down to about 1.5 x 10(-14) erg cm(-2)s(-1) where the contribution of discrete sources to the CXB grows to similar to 40-50%. A hardness ratio analysis reveals the presence of a wide range of spectral shapes and that a fairly large fraction of sources appear to be heavily absorbed, some of which showing soft components. A comparison of the flux distribution of different subsamples confirms the existence of a spectral hardening with decreasing flux. This effect is probably due to an increasing percentage of absorbed sources at faint fluxes, rather than to a gradual flattening of the spectral slope. Nearly all the sources for which adequate ROSAT exposures exist, have been detected in the soft X-rays. This confirms that soft spectral components are present even in strongly absorbed objects, and that a large population of sources undetectable below a few keV does not exist. A V-e/V-a test provides evidence for the presence of cosmological evolution of a magnitude similar to that found in soft X-ray extragalactic sources. Evolution is present both in normal and absorbed sources, with the latter population possibly evolving faster, although this effect could also be the result of complex selection effects. C1 ASI, BeppoSAX Sci Data Ctr, I-00131 Rome, Italy. Osservatorio Astron Roma, I-00044 Frascati, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Giommi, P (reprint author), ASI, BeppoSAX Sci Data Ctr, Via Corcolle 19, I-00131 Rome, Italy. EM giommi@napa.sdc.asi.it OI giommi, paolo/0000-0002-2265-5003 NR 78 TC 51 Z9 51 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD OCT PY 2000 VL 362 IS 3 BP 799 EP 808 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 376JX UT WOS:000165455400007 ER PT J AU Ros, E Guirado, JC Marcaide, JM Perez-Torres, MA Falco, EE Munoz, JA Alberdi, A Lara, L AF Ros, E Guirado, JC Marcaide, JM Perez-Torres, MA Falco, EE Munoz, JA Alberdi, A Lara, L TI VLBI imaging of the gravitational lens MG J0414+0534 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE techniques : interferometric; galaxies : jets; galaxies : quasars : individual : MG J0414+0534; cosmology : gravitational lensing ID MG-0414+0534; GALAXY AB We observed the quadruple gravitationally lensed image of MG J0414+0534 on 23 November 1997 with a global VLBI array at 8.4 GHz. We report wide-field imaging results of its four components at submilliarcsecond resolution, displaying complex core-like and jet-like extended structures. A simple model combining a singular isothermal ellipsoid to represent the main lens galaxy, external shear, and a singular isothermal sphere to represent an additional, nearby object accounts well for the core positions and flux densities of the VLBI images. This model predicts delays between the different lensed images of several weeks. C1 Max Planck Inst Radioastron, D-53121 Bonn, Germany. Univ Valencia, Dept Astron & Astrofis, E-46100 Burjassot, Valencia, Spain. Inst Nacl Tecn Aerosp, Ctr Astrobiol, Torrejon De Ardoz 28850, Madrid, Spain. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02183 USA. Inst Astrofis Canarias, E-38200 La Laguna, Tenerife, Spain. CSIC, Inst Astrofis Andalucia, E-18080 Granada, Spain. RP Ros, E (reprint author), Max Planck Inst Radioastron, Hugel 69, D-53121 Bonn, Germany. EM ros@mpifr-bonn.mpg.de NR 21 TC 37 Z9 37 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD OCT PY 2000 VL 362 IS 3 BP 845 EP 850 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 376JX UT WOS:000165455400012 ER PT J AU Wambsganss, J Schmidt, RW Colley, W Kundic, T Turner, EL AF Wambsganss, J Schmidt, RW Colley, W Kundic, T Turner, EL TI Microlensing results from APO monitoring of the double quasar Q0957+561A,B between 1995 and 1998 SO ASTRONOMY & ASTROPHYSICS LA English DT Letter DE galaxies : halos; cosmology : observations; cosmology : dark matter; cosmology : gravitational lensing ID GRAVITATIONAL LENS; QSO-0957+561; STARS; A,B AB If the halo of the lensing galaxy 0957+561 is made of massive compact objects (MACHOs), they must affect the lightcurves of the quasar images Q0957+561 A and B differently. We search for this microlensing effect in the double quasar by comparing monitoring data for the two images A and B obtained with the 3.5m Apache Point Observatory from 1995 to 1998 - with intensive numerical simulations. This way we test whether the halo of the lensing galaxy can be made of MACHOs of various masses. We can exclude a halo entirely made out of MACHOs with masses between 10(-6) M. and 10(-2) M. for quasar sizes of less than 3 x 10(14) h(60)(-1/2) 60 cm, hereby extending previous limits upwards by one order of magnitude. C1 Univ Potsdam, Inst Phys, D-14469 Potsdam, Germany. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Max Planck Inst Gravitat Phys, D-14476 Golm, Germany. Univ Melbourne, Sch Phys, Parkville, Vic 3052, Australia. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Renaissance Technol, Moscow 117333, Russia. Princeton Univ Observ, Princeton, NJ 08544 USA. RP Wambsganss, J (reprint author), Univ Potsdam, Inst Phys, Am Neuen Palais 10, D-14469 Potsdam, Germany. EM jkw@astro.physik.uni-potsdam.de; rschmidt@ast.cam.ac.uk; wcolley@barbecue.harvard.edu; tomislav@rentec.com; elt@astro.princeton.edu RI Turner, Edwin/A-4295-2011 NR 20 TC 19 Z9 19 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD OCT PY 2000 VL 362 IS 3 BP L37 EP L40 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 376JX UT WOS:000165455400001 ER PT J AU Montes, D Fernandez-Figueroa, MJ De Castro, E Cornide, M Latorre, A Sanz-Forcada, J AF Montes, D Fernandez-Figueroa, MJ De Castro, E Cornide, M Latorre, A Sanz-Forcada, J TI Multiwavelength optical observations of chromospherically active binary systems III. High resolution echelle spectra from CaIIH& K to CaIIIRT SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Review DE stars : activity; stars : binaries : close; stars : binaries : spectroscopic; stars : chromospheres; stars : late-type ID RS-CANUM-VENATICORUM; H-ALPHA EMISSION; ALL-SKY SURVEY; OBJECTIVE-PRISM DISCOVERIES; EXTREME-ULTRAVIOLET SOURCES; TIME-RESOLVED SPECTROSCOPY; SHORT-PERIOD SYSTEMS; CVN BINARIES; URSAE MAJORIS; PHOTOMETRIC VARIABILITY AB This is the third paper of a series aimed at studying the chromosphere of active binary systems using the information provided for several optical spectroscopic features. High resolution echelle spectra including all the optical chromospheric activity indicators from the Ca II H & K to Ca II IRT lines are analysed here for 16 systems. The chromospheric contribution in these lines has been determined using the spectral subtraction technique. Very broad wings have been found in the subtracted H alpha profilp of the very active star HU Vir. These profiles are well matched using a two-component Gaussian fit; (narrow and broad) ard the broad component carl be interpreted as arising from microflaring. Red-shifted absorption features in the H alpha line have been detected in several systems and excess emission in the blue wing of FG UMa was also detected. These features indicate that several dynamical processes, or a combination of them, may be involved. Using: the E-H alpha/E-H beta ratio as: a diagnostic we have detected prominence-like extended material viewed off the limb in many stars of the sample, and prominences viewed against the disk at some orbital phases in the dwarfs OU Gem and BF Lyn, The He I D-3 line has been detected as an absorption feature in mainly all the giants of the sample. Total filling-in of the He I D-3, probably due to microflaring activity, is observed in HU Vir. Self-absorption with red asymmetry is detected in the Ca II H & K lines of the giants 12 Cam: FG UMa and BM CVn. All the stars analysed show clear filled-in Ca II IRT lines or even notable emission reversal. The small values of the E-8542/E-8498 ratio we have found indicate Ca II IRT emission arises from plage-like regions. Orbital phase modulation of the chromospheric emission has been detected in some systems, in the case of HU Vir evidence of an active longitude area has been found. C1 Univ Complutense Madrid, Fac Ciencias Fis, Dept Astrofis, E-28040 Madrid, Spain. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Univ Complutense Madrid, Fac Ciencias Fis, Dept Astrofis, E-28040 Madrid, Spain. EM dmg@astrax.fis.ucm.es RI Montes, David/B-9329-2014; Sanz-Forcada, Jorge/C-3176-2017; De Castro, Elisa/J-2860-2016; Fernandez-Figueroa, Maria Jose/C-3108-2017 OI Montes, David/0000-0002-7779-238X; Sanz-Forcada, Jorge/0000-0002-1600-7835; De Castro, Elisa/0000-0001-5647-3892; Fernandez-Figueroa, Maria Jose/0000-0001-6892-198X NR 136 TC 49 Z9 49 U1 1 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD OCT PY 2000 VL 146 IS 1 BP 103 EP 140 PG 38 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 367RQ UT WOS:000090075600010 ER PT J AU Neuhauser, R Walter, FM Covino, E Alcala, JM Wolk, SJ Frink, S Guillout, P Sterzik, MF Comeron, F AF Neuhauser, R Walter, FM Covino, E Alcala, JM Wolk, SJ Frink, S Guillout, P Sterzik, MF Comeron, F TI Search for young stars among ROSAT All-Sky Survey X-ray sources in and around the R CrA dark cloud SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Article DE stars : formation; stars : luminosiy function, mass function; stars : pre-main sequence; X-rays : stars ID T-TAURI STARS; HIGH-RESOLUTION SPECTROSCOPY; ISOLATED NEUTRON-STAR; MAIN-SEQUENCE STARS; CORONAE-AUSTRALIS; OPTICAL IDENTIFICATIONS; MOLECULAR CLOUDS; STELLAR OBJECTS; FORMING REGION; STANDARD STARS AB We present the ROSAT All-Sky Survey data in a 126 deg(2) area in and around the CrA star forming region. With low-resolution spectroscopy of unidentified ROSAT sources we could find 19 new pre-main sequence stars, two of which are classical T Tauri stars, the others being weak-lined. The spectral types of these new T Tauri stars range from F7 to RIG. The two new classical T Tauri stars are located towards two small cloud-lets outside of the main CrA cloud. They appear to be similar to 10 Myrs Old, by comparing their location in the H-R diagram with isochrones for an assumed distance of 130 pc, the distance of the main CrA dark cloud. The new off-cloud weak-line T Tauri stars may have formed in similar cloudlets, which have dispersed recently. High-resolution spectra of our new T Tauri stars show that they have significantly more lithium absorption than zero-age main-sequence stars of the same spectral type, so that, they are indeed young. From those spectra we also obtained rotational and radial velocities. For some stars we found the proper motion in published catalogs. The direction and velocity of the 3D space motion - south relative to the galatic plane - of the CrA T Tauri stars is consistent with the dark cloud being formed originally by a high-velocity cloud impact onto the galactic plane, which triggered the star formation in CrA. We also present VRIJHK photometry for most of the new T Tauri stars to derive their luminosities, ages, and masses. C1 Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Osservatorio Astron Capodimonte, I-80131 Naples, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Astron Observ, CNRS UMR 7550, F-67000 Strasbourg, France. European So Observ, Santiago 19, Chile. European So Observ, D-85748 Garching, Germany. RP Neuhauser, R (reprint author), Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. OI Alcala, Juan Manuel/0000-0001-8657-095X; Covino, Elvira/0000-0002-6187-6685; Wolk, Scott/0000-0002-0826-9261 NR 83 TC 60 Z9 60 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD OCT PY 2000 VL 146 IS 2 BP 323 EP 347 PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 372WP UT WOS:000165257300007 ER PT J AU Markevitch, M Ponman, TJ Nulsen, PEJ Bautz, MW Burke, DJ David, LP Davis, D Donnelly, RH Forman, WR Jones, C Kaastra, J Kellogg, E Kim, DW Kolodziejczak, J Mazzotta, P Pagliaro, A Patel, S Van Speybroeck, L Vikhlinin, A Vrtilek, J Wise, M Zhao, P AF Markevitch, M Ponman, TJ Nulsen, PEJ Bautz, MW Burke, DJ David, LP Davis, D Donnelly, RH Forman, WR Jones, C Kaastra, J Kellogg, E Kim, DW Kolodziejczak, J Mazzotta, P Pagliaro, A Patel, S Van Speybroeck, L Vikhlinin, A Vrtilek, J Wise, M Zhao, P TI Chandra observation of abell 2142: Survival of dense subcluster cores in a merger SO ASTROPHYSICAL JOURNAL LA English DT Article DE cooling flows; galaxies : clusters : individual (Abell 2142); intergalactic medium; X-rays : general ID GALAXY CLUSTERS; COOLING FLOWS; EVOLUTION; SAMPLE; ROSAT AB We use Chandra data to map the gas temperature in the central region of the merging cluster A2142. The cluster is markedly nonisothermal; it appears that the central cooling flow has been disturbed but not destroyed by a merger. The X-ray image exhibits two sharp, bow-shaped, shocklike surface brightness edges or gas density discontinuities. However, temperature and pressure profiles across these edges indicate that these are not shock fronts. The pressure is reasonably continuous across these edges, while the entropy jumps in the opposite sense to that in a shock (i.e., the denser side of the edge has lower temperature, and hence lower entropy). Most plausibly, these edges delineate the dense subcluster cores that have survived a merger and ram pressure stripping by the surrounding shock-heated gas. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. Univ Wollongong, Wollongong, NSW 2500, Australia. MIT, Cambridge, MA 02139 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. NASA, MSFC, Washington, DC 20546 USA. Univ Rome, Rome, Italy. Russian Acad Sci, Inst Space Res, Moscow 117901, Russia. RP Markevitch, M (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Mazzotta, Pasquale/B-1225-2016; OI Mazzotta, Pasquale/0000-0002-5411-1748; Forman, William/0000-0002-9478-1682 NR 18 TC 355 Z9 355 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2000 VL 541 IS 2 BP 542 EP 549 DI 10.1086/309470 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 363FT UT WOS:000089825000004 ER PT J AU Medvedev, MV Narayan, R AF Medvedev, MV Narayan, R TI Axisymmetric self-similar equilibria of self-gravitating isothermal systems SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : kinematics and dynamics; galaxies : structure; hydrodynamics; ISM : kinematics and dynamics; stars : formation; stars : kinematics ID POWER-LAW GALAXIES; MODELS; CLOUDS AB We show that there are two families of axisymmetric self-similar equilibria of self-gravitating, rotating, isothermal systems: (1) cylindrically symmetric solutions in which the density varies with cylindrical radius as R-2(n+1), With -1 less than or equal to n less than or equal to 0 and (2) axially symmetric solutions in which the density varies as f(theta)/r(2), where r is the spherical radius and theta is the colatitude. The singular isothermal sphere is a special case of the latter class with f(theta) = constant. The axially symmetric equilibrium configurations form a two-parameter family of solutions and include equilibria which are asymmetric with respect to the equatorial plane. The asymmetric equilibria are, however, not force-free at the singular points r = 0, infinity, and their relevance to real systems is unclear. For each hydrodynamic equilibrium, we determine the phase-space distribution of the collisionless analog. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RRC Kurchatov Inst, Inst Nucl Fus, Moscow 123182, Russia. RP Medvedev, MV (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 17 TC 8 Z9 8 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2000 VL 541 IS 2 BP 579 EP 586 DI 10.1086/309459 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 363FT UT WOS:000089825000008 ER PT J AU Di Stefano, R AF Di Stefano, R TI On the nature and location of the microlenses SO ASTROPHYSICAL JOURNAL LA English DT Article DE dark matter; gravitational lensing; stars : low-mass, brown dwarfs ID GRAVITATIONAL LENSING EXPERIMENT; LARGE-MAGELLANIC-CLOUD; GALACTIC BULGE; BINARY LENS; MACHO PROJECT; EVENTS; HALO; STARS; CANDIDATE; PHOTOMETRY AB This paper uses the caustic-crossing events in the microlens data sets to explore the nature and location of the lenses. We conclude that (1) the large majority of lenses, whether they are luminous or dark, are likely to be binaries; (2) blending is an important feature of all the data sets; and (3) most of the LMC/SMC events to date are due to lenses in the Magellanic Clouds, if, as is suspected, the caustic-crossing events along the directions to the Magellanic Clouds are due to lenses located in the Clouds. Although these conclusions are based on a very small number of events, they are subject to a variety of detailed tests. If they are correct, a large fraction of lenses along the direction to the LMC may be ordinary stellar binary systems, just as are the majority of the lenses along the direction to the Bulge. Thus, a better understanding of the larger-than-anticipated value derived for the Bulge optical depth may allow us to better interpret the large value derived for the optical depth to the LMC. Indeed, binarity and blending in the data sets may illuminate connections among several other puzzles: the dearth of binary-source light curves, the dearth of non-caustic-crossing, perturbed, binary-lens events, and the dearth of obviously blended point-lens events. C1 Tufts Univ, Dept Phys & Astron, Medford, MA 02155 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Di Stefano, R (reprint author), Tufts Univ, Dept Phys & Astron, Medford, MA 02155 USA. EM rdistefano@cfa.harvard.edu NR 62 TC 14 Z9 14 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2000 VL 541 IS 2 BP 587 EP 596 DI 10.1086/309474 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 363FT UT WOS:000089825000009 ER PT J AU Medvedev, MV AF Medvedev, MV TI Particle heating by nonlinear Alfvenic turbulence in advection-dominated accretion flows SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; MHD; plasmas; turbulence; waves ID SAGITTARIUS-A-ASTERISK; BLACK-HOLE; MAGNETOHYDRODYNAMIC TURBULENCE; WAVE NONLINEARITY; MODEL; SPECTRUM; DISKS; INSTABILITY; NGC-4258; PLASMAS AB Particle heating in advection-dominated accretion flows (ADAFs) by nonlinear MHD (Alfvenic) turbulence is investigated. Such turbulence with highly fluctuating magnetic fields, (B) over tilde similar to B-0, is believed to be naturally produced by the magnetic shearing instability near the nonlinear saturation. It is shown that the energy is dissipated in the parallel cascade, which occurs because of nonlinear compressibility of high-amplitude turbulence and predominantly heats protons but not electrons. The conservative limit on the electron-to-proton heating fraction is delta less than or similar to a few times 10(-2). C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RRC, Kurchatov Inst, Inst Nucl Fus, Moscow 123182, Russia. RP Medvedev, MV (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 36 TC 21 Z9 22 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2000 VL 541 IS 2 BP 811 EP 820 DI 10.1086/309449 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 363FT UT WOS:000089825000028 ER PT J AU Perna, R Raymond, J Narayan, R AF Perna, R Raymond, J Narayan, R TI X-ray line diagnostics of hot accretion flows around black holes SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; galaxies : nuclei; Galaxy : center; radiation mechanisms : thermal; X-rays : stars ID ADVECTION-DOMINATED ACCRETION; DIELECTRONIC SATELLITE SPECTRA; HELIUM-LIKE IONS; RATE COEFFICIENTS; A-ASTERISK; EXCITATION; IRON; VARIABILITY; EMISSION AB We compute X-ray emission Lines from thermal plasma in hot accretion flows. We show that line profiles are strong probes of the gas dynamics, and we present line-ratio diagnostics which are sensitive to the distribution of mass with temperature in the flow. We show how these can be used to constrain the run of density with radius and the size of the hot region. We also present diagnostics which are primarily sensitive to the importance of recombination versus collisional ionization and which could help discriminate advection-dominated accretion flows from photoionization-dominated accretion disk coronae. We apply our results to the Galactic center source Sagittarius A* and to the nucleus of M87. We find that the brightest predicted lines are within the detection capability of current X-ray instruments. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Perna, R (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 32 TC 13 Z9 13 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2000 VL 541 IS 2 BP 898 EP 907 DI 10.1086/309466 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 363FT UT WOS:000089825000036 ER PT J AU Mauche, CW Raymond, JC AF Mauche, CW Raymond, JC TI Extreme Ultraviolet Explorer observations of OY Carinae in superoutburst SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; binaries : eclipsing; novae, cataclysmic variables; stars : individual (OY Carinae); stars : winds, outflows; ultraviolet : stars ID X-RAY-EMISSION; DISK BOUNDARY-LAYERS; NOVA HT-CASSIOPEIAE; LINE-DRIVEN WINDS; CATACLYSMIC VARIABLES; EUVE OBSERVATIONS; DWARF NOVAE; SS CYGNI; VW HYDRI; ECLIPSE AB The Extreme Ultraviolet Explorer (EUVE) satellite was used for three days beginning on 1997 March 26.96 UT to obtain photometric and spectroscopic observations of the eclipsing SU UMa-type dwarf nova OY Carinae in superoutburst. Because of the longer time on source (143 ks), the larger number of eclipses observed (17), and the higher count rate in the detector (0.5-2.2 counts s(-1)), we are able to significantly strengthen previous reports that there is little or no eclipse by the secondary of the EUV emission region of OY Car in superoutburst. The mean EUVE spectrum extends from 70 to 190 Angstrom and contains broad (FWHM approximate to 1 Angstrom) emission lines of N V, O V-O VI, Ne V-Ne VII, Mg IV-Mg VI, Fe VI-Fe VIII, and possibly Fe XXIII. Good fits of the observed spectrum are obtained with a model (similar to that of Seyfert 2 galaxies) wherein radiation from the boundary layer and accretion disk is scattered into the line of sight by the system's photoionized accretion disk wind. It is possible to trade off continuum luminosity for wind optical depth, but reasonable models have a boundary layer temperature T(bl) approximate to 90-130 kK and a boundary layer and accretion disk luminosity L(bl) = L(disk) less than or similar to 4 x 10(34) ergs s(-1) approximate to 10 L(circle dot) corresponding to a mass accretion rate (M)over dot(a) less than or similar to 10(-8) M(circle dot) yr(-1); an absorbing column density N(H) approximate to 1.6-3.5 x 10(19) cm(-2); and a wind mass-loss rate (M)over dot(w) less than or similar to 10(-10) M(circle dot) yr(-1) approximate to 0.01 M(a). Because radiation pressure alone falls an order of magnitude short of driving such a wind, magnetic forces must also play a role in driving the wind of OY Car in superoutburst. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Mauche, CW (reprint author), Lawrence Livermore Natl Lab, L-43,7000 E Ave, Livermore, CA 94550 USA. EM mauche@cygaus.llnl.gov; jraymond@cfa.harvard.edu NR 59 TC 32 Z9 32 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2000 VL 541 IS 2 BP 924 EP 936 DI 10.1086/309489 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 363FT UT WOS:000089825000039 ER PT J AU Marengo, M Jayawardhana, R Fazio, GG Hoffmann, WF Hora, JL Dayal, A Deusch, LK AF Marengo, M Jayawardhana, R Fazio, GG Hoffmann, WF Hora, JL Dayal, A Deusch, LK TI Mid-infrared imaging of the massive young star AFGL 2591: Probing the circumstellar environment of an outflow source SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; ISM : jets and outflows; stars : individual (AFGL 2591); stars : pre-main-sequence ID MOLECULAR OUTFLOW; STELLAR OBJECTS; FORMING REGIONS; GL-2591; AFGL-2591; CO; POLARIMETRY; IMAGES; SHOCKS; JET AB Most, if not all, stars are now believed to produce energetic outflows during their formation. Yet, almost 20 years after the discovery of bipolar outflows from young stars, the origins of this violent phenomenon are not well understood. One of the difficulties of probing the outflow process, particularly in the case of massive embedded stars, is a deficit of high spatial resolution observations. Here we present subarcsecond-resolution midinfrared images of one massive young stellar object, AFGL 2591, and its immediate surroundings. Our images, at 11.7, 12.5, and 18.0 mu m, reveal a knot of emission approximate to 6 " southwest of the star, which may be evidence for a recent ejection event or an embedded companion star. This knot is roughly coincident with a previously seen near-infrared reflection nebula and a radio source, and it lies within the known large-scale CO outflow. We also find a new faint northwest source that may be another embedded lower luminosity star. The IRAS mid-infrared spectrum of AFGL 2591 shows a large silicate absorption feature at 10 mu m, implying that the primary source is surrounded by an optically thick dusty envelope. We discuss the interrelationship of these phenomena and suggest that mid-infrared imaging and spectroscopy provide powerful tools for probing massive star birth. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. CALTECH, IPAC, Pasadena, CA 91125 USA. Boston Univ, Dept Astron, CAS 519, Boston, MA 02215 USA. RP Marengo, M (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 28 TC 8 Z9 8 U1 1 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2000 VL 541 IS 2 BP L63 EP L66 DI 10.1086/312899 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 363FX UT WOS:000089825400008 ER PT J AU Tucker, DL Oemler, A Hashimoto, Y Shectman, SA Kirshner, RP Lin, H Landy, SD Schechter, PL Allam, SS AF Tucker, DL Oemler, A Hashimoto, Y Shectman, SA Kirshner, RP Lin, H Landy, SD Schechter, PL Allam, SS TI Loose groups of galaxies in the Las Campanas Redshift Survey SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE catalogs; galaxies : clusters : general; galaxies : distances and redshifts; large-scale structure of universe; surveys ID PISCES-PERSEUS SUPERCLUSTER; LUMINOSITY FUNCTION; DENSITY RELATION; STAR-FORMATION; RICH CLUSTERS; CFA SURVEY; CATALOG; ENVIRONMENT; ZONE AB A "friends-of-friends" percolation algorithm has been used to extract a catalog of deltan/n = 80 density enhancements (groups) from the six slices of the Las Campanas Redshift Survey (LCRS). The full catalog contains 1495 groups and includes 35% of the LCRS galaxy sample. A clean sample of 394 groups has been derived by culling groups from the full sample that either are too close to a slice edge, have a crossing time greater than a Hubble time, have a corrected velocity dispersion of zero, or contain a 55 " "orphan" (a galaxy with a mock redshift that was excluded from the original LCRS redshift catalog due to its proximity to another galaxy-i.e., within 55 "). Median properties derived from the clean sample include a line-of-sight velocity dispersion sigma (los) = 164 km s(-1), crossing time t(cr), = 0.10 H-0(-1), harmonic radius R-h = 0.58 h(-1) Mpc, pairwise separation R-p = 0.64 h(-1) Mpc, virial mass M-vir = 1.90 x 10(13) h(-1) M., total group R-band luminosity L-tot = 1.30 x 10(11) h(-2) L., and R-band mass-to-light ratio M/L = 171 h M./L.; the median number of observed members in a group is three. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Carnegie Observ, Pasadena, CA 91101 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. Helwan Observ, Natl Res Inst Astron & Geophys, Cairo, Egypt. Yale Univ, Dept Astron, New Haven, CT 06520 USA. RP Tucker, DL (reprint author), Fermi Natl Accelerator Lab, MS 127,POB 500, Batavia, IL 60510 USA. NR 54 TC 72 Z9 72 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD OCT PY 2000 VL 130 IS 2 BP 237 EP 265 DI 10.1086/317348 PG 29 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 378HX UT WOS:000165579900001 ER PT J AU Fleischer, RC Olson, SL James, HF Cooper, AC AF Fleischer, RC Olson, SL James, HF Cooper, AC TI Identification of the extinct Hawaiian eagle (Haliaeetus) by mtDNA sequence analysis SO AUK LA English DT Article ID ANCIENT DNA; RECONSTRUCTIONS; SPECIATION; EVOLUTION; ORDER; AGES C1 Smithsonian Inst, Natl Zool Pk, Genet Mol Lab, Washington, DC 20008 USA. Univ Durham, Dept Biol Sci, Durham DH1 3LE, England. Smithsonian Inst, Museum Natl Hist Nat, Dept Vertebrate Zool, Washington, DC 20560 USA. Univ Oxford, Dept Zool, Oxford OX2 6QS, England. Univ Oxford, Dept Biol Anthropol, Oxford OX2 6QS, England. RP Fleischer, RC (reprint author), Smithsonian Inst, Natl Zool Pk, Genet Mol Lab, Washington, DC 20008 USA. RI Cooper, Alan/E-8171-2012 OI Cooper, Alan/0000-0002-7738-7851 NR 25 TC 41 Z9 43 U1 0 U2 9 PU AMER ORNITHOLOGISTS UNION PI LAWRENCE PA ORNITHOLOGICAL SOC NORTH AMER PO BOX 1897, LAWRENCE, KS 66044-8897 USA SN 0004-8038 J9 AUK JI AUK PD OCT PY 2000 VL 117 IS 4 BP 1051 EP 1056 DI 10.1642/0004-8038(2000)117[1051:IOTEHE]2.0.CO;2 PG 6 WC Ornithology SC Zoology GA 367PK UT WOS:000090070500025 ER PT J AU Walters, JR Beissinger, SR Fitzpatrick, JW Greenberg, R Nichols, JD Pulliam, HR Winkler, DW AF Walters, JR Beissinger, SR Fitzpatrick, JW Greenberg, R Nichols, JD Pulliam, HR Winkler, DW TI The AOU Conservation Committee review of the biology, status, and management of cape sable seaside sparrows: Final report SO AUK LA English DT Article ID SNAIL KITE; POPULATION VIABILITY; EVOLUTION C1 Virginia Polytech Inst & State Univ, Dept Biol, Blacksburg, VA 24061 USA. Univ Calif Berkeley, Dept Environm Sci Policy & Management, Berkeley, CA 94720 USA. Cornell Univ, Ornithol Lab, Ithaca, NY 14850 USA. Smithsonian Inst, Natl Zool Pk, Smithsonian Migratory Bird Ctr, Washington, DC 20008 USA. US Geol Survey, Biol Resources Div, Laurel, MD 20708 USA. Univ Georgia, Inst Ecol, Athens, GA 30605 USA. Cornell Univ, Dept Ecol & Evolutionary Biol, Ithaca, NY 14853 USA. RP Walters, JR (reprint author), Virginia Polytech Inst & State Univ, Dept Biol, Blacksburg, VA 24061 USA. RI Beissinger, Steven/F-3809-2012 NR 50 TC 13 Z9 14 U1 0 U2 7 PU AMER ORNITHOLOGISTS UNION PI LAWRENCE PA ORNITHOLOGICAL SOC NORTH AMER PO BOX 1897, LAWRENCE, KS 66044-8897 USA SN 0004-8038 J9 AUK JI AUK PD OCT PY 2000 VL 117 IS 4 BP 1093 EP 1115 DI 10.1642/0004-8038(2000)117[1093:TACCRO]2.0.CO;2 PG 23 WC Ornithology SC Zoology GA 367PK UT WOS:000090070500033 ER PT J AU Pope, DS AF Pope, DS TI Video playback experiments testing the function of claw waving in the sand fiddler crab SO BEHAVIOUR LA English DT Article ID UCA-PUGILATOR; ANIMAL BEHAVIOR; DISPLAY; FEMALES; CONTEXT; SIGNAL AB Like many territory advertisement signals, the claw waving display of fiddler crabs (genus Uca)) is commonly thought to have the dual function of simultaneously repelling males and attracting females. I have found, however, that male sand fiddler crabs (U. pugilator) wave significantly more in the presence of females than males, suggesting that their waves are primarily directed to females. Here I use laboratory video playback experiments to ask whether male and female LI. pugilator are both responsive to the display. Males and females were presented with video of an example of either a waving or a feeding male conspecific, or no video, and their behavior was measured in seven behavioral categories that were then collapsed into three principal components. Analysis of variance of females' principal component scores revealed significant differences in their behavior in the presence of waving male video compared with feeding male video or no video, demonstrating that females attend to the display. Male behavior, however, was not significantly different between the three treatments, which is inconsistent with the hypothesis that claw waving serves to repel or threaten other males. These results, together with my recent work on male signaling behavior, suggests that the claw waving display of U. pugilator is a signal primarily directed to females and attended to by females, and thus is not an example of a dual function signal. C1 Duke Univ, Dept Zool, Durham, NC 27706 USA. RP Pope, DS (reprint author), Smithsonian Trop Res Inst, Unit 0948, APO, AA 34002 USA. EM poped@naos.si.edu NR 33 TC 13 Z9 14 U1 0 U2 3 PU BRILL ACADEMIC PUBLISHERS PI LEIDEN PA PLANTIJNSTRAAT 2, P O BOX 9000, 2300 PA LEIDEN, NETHERLANDS SN 0005-7959 J9 BEHAVIOUR JI Behaviour PD OCT PY 2000 VL 137 BP 1349 EP 1360 DI 10.1163/156853900501962 PN 10 PG 12 WC Behavioral Sciences; Zoology SC Behavioral Sciences; Zoology GA 392RX UT WOS:000166427200005 ER PT J AU Blanco, JM Gee, G Wildt, DE Donoghue, AM AF Blanco, JM Gee, G Wildt, DE Donoghue, AM TI Species variation in osmotic, cryoprotectant, and cooling rate tolerance in poultry, eagle, and peregrine falcon spermatozoa SO BIOLOGY OF REPRODUCTION LA English DT Article DE male sexual function; seasonal reproduction; sperm; sperm motility and transport ID ACTIVATION-ENERGY; CRYOPRESERVATION; GLYCEROL; CELLS; PERMEABILITY; SPERM; SEMEN; FOWL AB Potential factors influencing spermatozoa survival to cryopreservation and thawing were analyzed across a range of the following avian species: domestic chicken (Gallus domesticus), domestic turkey (Meleagris gallopavo), golden eagle (Aquila chrysaetos), Bonelli's eagle (Hieraaetus fasciatus), imperial eagle (Aquila adalberti, and peregrine falcon (Falco peregrinus). Studies focused on spermatozoa tolerance to the following: 1) osmotic stress, 2) different extracellular concentrations of the cryoprotectant dimethylacetamide (DMA), 3) equilibration times of 1 versus 4 h, 4) equilibration temperature of 4 versus 21 degrees C, and 5) rapid versus slow cooling before cryopreservation and standard thawing. Sperm viability was assessed with the live/dead stain (SYBR-14/propidium iodine). Sperm viability at osmolalities greater than or equal to 800 mOsm was higher (P < 0.05) in raptor than poultry semen. Return to isotonicity after exposure to hypertonicity (3000 mOsm) decreased (P < 0.05) number of viable spermatozoa in chicken, turkey, and golden and Bonelli's eagle spermatozoa but not in imperial eagle or peregrine falcon spermatozoa. Differences were found in spermatozoa resistance to hypotonic conditions, with eagle species demonstrating the most tolerance. Semen, equilibrated for 1 h (4 degrees C) in diluent containing DMA (greater than or equal to 2.06 M), experienced decreased (P < 0.05) spermatozoa survival in all species, except the golden eagle and peregrine falcon. Number of surviving spermatozoa diminished progressively with increasing DMA concentrations in all species. Increased equilibration temperature (from 4 to 21 degrees C) markedly reduced (P ( 0.05) spermatozoa survival in all species except the Bonelli's eagle and turkey. Rapid cooling was detrimental (P < 0.05) to spermatozoa from all species except the imperial eagle and the chicken. These results demonstrate that avian spermatozoa differ remarkably in response to osmotic changes, DMA concentrations, equilibration time, temperature, and survival after fast or slow freezing. These differences emphasize the need for species-specific studies in the development and enhancement of assisted breeding for poultry and endangered species. C1 USDA ARS, LPSI, Germplasm & Gamete Physiol Lab, Beltsville, MD 20705 USA. US Fish & Wildlife Serv, Patuxent Wildlife Res Ctr, Laurel, MD 20708 USA. Smithsonian Inst, Conservat & Res Ctr, Natl Zool Pk, Front Royal, VA 22630 USA. CERI, Ctr Studies Iberian Raptors, Toledo, Spain. RP Donoghue, AM (reprint author), Univ Arkansas, PPSR, ARS, USDA,Poultry Sci Ctr O304, Fayetteville, AR 72701 USA. NR 38 TC 92 Z9 98 U1 1 U2 14 PU SOC STUDY REPRODUCTION PI MADISON PA 1603 MONROE ST, MADISON, WI 53711-2021 USA SN 0006-3363 J9 BIOL REPROD JI Biol. Reprod. PD OCT PY 2000 VL 63 IS 4 BP 1164 EP 1171 DI 10.1095/biolreprod63.4.1164 PG 8 WC Reproductive Biology SC Reproductive Biology GA 357GC UT WOS:000089489300028 PM 10993841 ER PT J AU Basset, Y Novotny, V Miller, SE Pyle, R AF Basset, Y Novotny, V Miller, SE Pyle, R TI Quantifying biodiversity: Experience with parataxonomists and digital photography in Papua New Guinea and Guyana SO BIOSCIENCE LA English DT Article ID RAIN-FOREST; INSECT HERBIVORES; HOST-SPECIFICITY; ABUNDANCE; RICHNESS; FICUS C1 Smithsonian Trop Res Inst, Balboa, Ancon, Panama. Acad Sci Czech Republ, Inst Entomol, CR-37005 Ceske Budejovice, Czech Republic. Univ S Bohemia, Fac Biol, Ceske Budejovice, Czech Republic. Int Ctr Insect Physiol & Ecol, Nairobi, Kenya. Bishop Museum, Honolulu, HI 96817 USA. RP Basset, Y (reprint author), Smithsonian Trop Res Inst, Apartado 2072, Balboa, Ancon, Panama. RI Basset, Yves/B-6642-2014; Novotny, Vojtech/G-9434-2014; OI Novotny, Vojtech/0000-0001-7918-8023; Miller, Scott/0000-0002-4138-1378 NR 44 TC 56 Z9 60 U1 0 U2 11 PU AMER INST BIOLOGICAL SCI PI WASHINGTON PA 1444 EYE ST, NW, STE 200, WASHINGTON, DC 20005 USA SN 0006-3568 J9 BIOSCIENCE JI Bioscience PD OCT PY 2000 VL 50 IS 10 BP 899 EP 908 DI 10.1641/0006-3568(2000)050[0899:QBEWPA]2.0.CO;2 PG 10 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 367PA UT WOS:000090069600016 ER PT J AU Swain, HM Kress, WJ AF Swain, HM Kress, WJ TI Biological challenges for the new millennium: Feedback from "Synthesis" sessions at the 2000 AIBS Annual Meeting SO BIOSCIENCE LA English DT Editorial Material C1 Archbold Biol Stn, Lake Placid, FL 33852 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, Washington, DC USA. RP Swain, HM (reprint author), Archbold Biol Stn, Lake Placid, FL 33852 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST BIOLOGICAL SCI PI WASHINGTON PA 1444 EYE ST, NW, STE 200, WASHINGTON, DC 20005 USA SN 0006-3568 J9 BIOSCIENCE JI Bioscience PD OCT PY 2000 VL 50 IS 10 BP 933 EP 936 PG 4 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 367PA UT WOS:000090069600018 ER PT J AU Roubik, DW AF Roubik, DW TI Pollination system stability in tropical America SO CONSERVATION BIOLOGY LA English DT Article ID FOREST FRAGMENTATION C1 Smithsonian Inst, Smithsonian Trop Res Inst, Balboa, Panama. RP Roubik, DW (reprint author), Smithsonian Inst, Smithsonian Trop Res Inst, Apartado 2072, Balboa, Panama. NR 19 TC 26 Z9 30 U1 0 U2 7 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD OCT PY 2000 VL 14 IS 5 BP 1235 EP 1236 DI 10.1046/j.1523-1739.2000.00016.x PG 2 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 363CL UT WOS:000089816800007 ER PT J AU Ralls, K Taylor, BL AF Ralls, K Taylor, BL TI Better policy and management decisions through explicit analysis of uncertainty: New approaches from marine conservation - Introduction SO CONSERVATION BIOLOGY LA English DT Editorial Material C1 Smithsonian Inst, Natl Zool Pk, Washington, DC 20008 USA. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. RP Ralls, K (reprint author), Smithsonian Inst, Natl Zool Pk, Washington, DC 20008 USA. NR 4 TC 7 Z9 9 U1 0 U2 3 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD OCT PY 2000 VL 14 IS 5 BP 1240 EP 1242 DI 10.1046/j.1523-1739.2000.99408.x PG 3 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 363CL UT WOS:000089816800009 ER PT J AU Haight, RG Ralls, K Starfield, AM AF Haight, RG Ralls, K Starfield, AM TI Designing species translocation strategies when population growth and future funding are uncertain SO CONSERVATION BIOLOGY LA English DT Article ID CONSERVATION; OPTIMIZATION; MANAGEMENT; VIABILITY; RECOVERY AB When translocating individuals to found new populations, managers must allocate limited funds among release and monitoring activities that differ in method, cost, and probable result. In addition, managers are increasingly expected to justify the funding decisions they have made. Within the framework of decision analysis, we used robust optimization to formulate and solve different translocation problems in which both population growth and future funding were uncertain. Performance criteria included maximizing: mean population size and minimizing the risk (1) of undesirable population-size outcomes. Robust optimization provided several insights into the design of translocation strategies: (1) risk reduction is obtained at the expense of mean population size; (2) as survival of released animals becomes more important, funds should be allocated to release methods with lower risks of failure, regardless of costs; (3) the performance gain from monitoring drops as the proportion of a fixed budget required to pay for monitoring increases; and (4) as the likelihood of obtaining future funding increases, more of the existing budget should be spent on building release capacity rather than saved for future operating costs. These relationships highlight the importance of performance criteria and economic costs in determining optimal release and monitoring strategies. C1 US Forest Serv, N Cent Res Stn, St Paul, MN 55108 USA. Smithsonian Inst, Natl Zool Pk, Washington, DC 20008 USA. Univ Minnesota, Dept Ecol Evolut & Behav, St Paul, MN 55108 USA. RP Haight, RG (reprint author), US Forest Serv, N Cent Res Stn, 1992 Folwell Ave, St Paul, MN 55108 USA. NR 19 TC 21 Z9 21 U1 1 U2 13 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD OCT PY 2000 VL 14 IS 5 BP 1298 EP 1307 DI 10.1046/j.1523-1739.2000.99414.x PG 10 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 363CL UT WOS:000089816800015 ER PT J AU Williamson, GB Laurance, WF Oliveira, AA Delamonica, P Gascon, C Lovejoy, TE Pohl, L AF Williamson, GB Laurance, WF Oliveira, AA Delamonica, P Gascon, C Lovejoy, TE Pohl, L TI Amazonian tree mortality during the 1997 El Nino drought SO CONSERVATION BIOLOGY LA English DT Article ID LOWLAND RAIN-FOREST; TROPICAL FORESTS; DYNAMICS; FIRE AB In 1997, the Amazon Basin experienced an exceptionally severe El Nino drought. We assessed effects of this rare event on mortality rates of trees in intact rainforest based on data from permanent plots. Long-term (5- to 13-year) mortality rates averaged only 1.12% per year prior to the drought. During the drought year, annual mortality jumped to 1.91% but abruptly fell back to 1.23% in the year following El Nino. Trees dying during the drought dirt not differ significantly in site or species composition from those that died previously, and there was no detectable effect of soil texture on mortality rates. These results suggest that intact Amazonian rainforests are relatively resistant to severe El Nino events. C1 Louisiana State Univ, Dept Biol Sci, Baton Rouge, LA 70803 USA. INPA, Natl Inst Amazonian Res, Biol Dynam Forest Fragments Project, BR-69011970 Manaus, Amazonas, Brazil. Univ Estadual Paulista, Lab Bot, BR-01310100 Sao Paulo, Brazil. Smithsonian Inst, Secretary Biodivers & Conservat, Washington, DC 20560 USA. RP Williamson, GB (reprint author), Louisiana State Univ, Dept Biol Sci, Baton Rouge, LA 70803 USA. EM btwill@lsu.edu RI Laurance, William/B-2709-2012; Oliveira, Alexandre/G-8830-2012 OI Oliveira, Alexandre/0000-0001-5526-8109 NR 17 TC 111 Z9 119 U1 2 U2 35 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD OCT PY 2000 VL 14 IS 5 BP 1538 EP 1542 DI 10.1046/j.1523-1739.2000.99298.x PG 5 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 363CL UT WOS:000089816800043 ER PT J AU Gray, HM Christy, JH AF Gray, HM Christy, JH TI Predation by the grapsid crab, Armases angustum (Smith, 1870), on tadpoles of the green poison frog, Dendrobates auratus Girard, 1855 SO CRUSTACEANA LA English DT Article ID ALKALOIDS C1 McGill Univ, Redpath Museum, Montreal, PQ H3A 2K6, Canada. Smithsonian Trop Res Inst, Balboa, Ancon, Panama. RP Gray, HM (reprint author), McGill Univ, Redpath Museum, 859 Sherbrooke St W, Montreal, PQ H3A 2K6, Canada. NR 7 TC 11 Z9 12 U1 0 U2 2 PU BRILL ACADEMIC PUBLISHERS PI LEIDEN PA PLANTIJNSTRAAT 2, P O BOX 9000, 2300 PA LEIDEN, NETHERLANDS SN 0011-216X J9 CRUSTACEANA JI Crustaceana PD OCT PY 2000 VL 73 BP 1023 EP 1025 DI 10.1163/156854000504958 PN 8 PG 3 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 384ZM UT WOS:000165977200014 ER PT J AU Orrock, JL Pagels, JF McShea, WJ Harper, EK AF Orrock, JL Pagels, JF McShea, WJ Harper, EK TI Predicting presence and abundance of a small mammal species: The effect of scale and resolution SO ECOLOGICAL APPLICATIONS LA English DT Article DE Appalachian Mountains, USA; Clethrionomys gapperi; habitat selection; indicator species analysis; landscape classification; logistic regression; population ecology ID EXPLICIT POPULATION-MODELS; CLETHRIONOMYS-GAPPERI; HABITAT SELECTION; MULTIPLE SCALES; PATTERNS; DEMOGRAPHY; FORESTS; AVAILABILITY; ENVIRONMENT; ASSEMBLAGES AB Management of small mammal communities in forest ecosystems requires a working knowledge of the scales at which species presence and abundance can best be predicted. Habitat-based models were developed to characterize the distribution of a boreal relict, the southern red-backed vole, Clethrionomys gapperi, in the southern Appalachian Mountains, USA, at three hierarchical scales of analysis. Vole presence and abundance were most evident at the high-resolution (macrohabitat) scale, followed by the intermediate-resolution scale. The low-resolution model was the least effective for predicting presence or abundance and reflects the need for more resolute landscape classification systems if small mammal populations are to be accounted for in an ecologically relevant manner. Tree and shrub communities indicative of suitable vole habitat included Fraxinus pennsylvanica and Tsuga canadensis in the canopy and Carpinus caroliniana in the understory. Vole abundance increased with incidence of tree species such as Betula alleghaniensis, Pinus rigida, and Prunus serotina in the canopy, and Acer spicatum and woody vines in the understory. Voles were associated with northwest-facing high-elevation sites with abundant rocky substrate, likely a reflection of physiological water and thermal requirements, biogeographic influences, and the importance of substrate complexity for decreasing inter- and intraspecific interactions and avoidance of predators. Identification of the most effective resolution of landscape characterization improves habitat-based models of C. gapperi population dynamics in managed landscapes. Low-resolution habitat classifications may suffice for detecting suitable vole habitats within forest types, but prediction of vole abundance is most accurate at the greatest resolution, i.e., the macrohabitat scale. The utility of forest communities and habitats at various scales to predict vole presence and abundance suggests that C. gapperi may be a useful indicator species for identification and assessment of habitat important for rare small mammal species in the southern Appalachians. C1 Virginia Commonwealth Univ, Dept Biol, Richmond, VA 23284 USA. Smithsonian Inst, Conservat & Res Ctr, Front Royal, VA 22630 USA. Univ Minnesota, Dept Fisheries & Wildlife, St Paul, MN 55108 USA. RP Orrock, JL (reprint author), Iowa State Univ, Dept Anim Ecol, 124 Sci 2, Ames, IA 50011 USA. EM jorrock@iastate.edu NR 73 TC 65 Z9 69 U1 3 U2 29 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1990 M STREET NW, STE 700, WASHINGTON, DC 20036 USA SN 1051-0761 EI 1939-5582 J9 ECOL APPL JI Ecol. Appl. PD OCT PY 2000 VL 10 IS 5 BP 1356 EP 1366 DI 10.2307/2641291 PG 11 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA 361VK UT WOS:000089744800013 ER PT J AU Roberts, DL Cooper, RJ Petit, LJ AF Roberts, DL Cooper, RJ Petit, LJ TI Flock characteristics of ant-following birds in premontane moist forest and coffee agroecosystems SO ECOLOGICAL APPLICATIONS LA English DT Article DE ant-following birds; army ants; biodiversity and agriculture; Dendrocincla homochroa; Eciton burchelli; Eucometris penicillata; forest fragmentation; Labidus predator; Panama; shade coffee plantations; understory insectivores ID TROPICAL RAIN-FOREST; UNDERSTORY BIRDS; SHADE COFFEE; MEXICO; FRAGMENTATION; BIODIVERSITY; PLANTATIONS; EXTINCTIONS; RESPONSES; DIVERSITY AB We studied avian attendance at swarms of Eciton burchelli and Labidus praedator (Hymenoptera: Formicidae: Ecitoninae) over 5-mo periods in both 1996 and 1997, at elevations between 1400 m and 1800 m in western Panama. We conducted area searches for swarms of raiding ants and attendant birds in intact forest, traditional shade coffee habitats both adjacent to and distant from forest, and in sun coffee habitats, quantifying the size and composition of attendant flocks. All habitats except sun coffee supported numerous army ant swarms and thus a diverse assemblage of ant-following birds. A total of 411 swarming occasions attracted 126 bird species of 28 families. Of the 103 resident species, two were obligate ant-following birds, the Ruddy Woodcreeper (Dendrocincla homochroa) and the Gray-headed Tanager (Eucometris penicillata). Of the remaining species, 18 were wintering Nearctic migrants, and five were transient Nearctic migrants. Nearctic migrant species composed a greater percentage of the attendant species in shade coffee habitats as compared to forest. Several species of forest resident birds that correspond with particular foraging guilds, such as understory bark insectivores, including D. homochroa, regularly occurred in adjacent shade coffee but were never observed at swarms in distant shade coffee. Army ants may therefore be a mechanism for bringing forest birds into shade coffee, but only to a point. In western Panama, mid-elevational traditional shade coffee plantations can provide additional habitat for the diverse avifauna that attend army ant swarms. With increasing distance from large areas of continuous forest, however, the value of traditional shade coffee habitats is lessened for certain components of the bird community. Thus, protection of these habitats adjacent to intact forest should receive priority. Additionally, current transformation of coffee-growing practices, including the removal of shade trees to grow coffee in full sun, will negatively affect army ants and their associated avian followers. C1 Univ Georgia, Warnell Sch Forest Resources, Athens, GA 30602 USA. Natl Zool Pk, Smithsonian Migratory Bird Ctr, Washington, DC 20008 USA. RP Roberts, DL (reprint author), Univ Georgia, Warnell Sch Forest Resources, Athens, GA 30602 USA. NR 46 TC 35 Z9 35 U1 1 U2 20 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1707 H ST NW, STE 400, WASHINGTON, DC 20006-3915 USA SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD OCT PY 2000 VL 10 IS 5 BP 1414 EP 1425 DI 10.1890/1051-0761(2000)010[1414:FCOAFB]2.0.CO;2 PG 12 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA 361VK UT WOS:000089744800017 ER PT J AU Bosch, J Rand, AS Ryan, MJ AF Bosch, J Rand, AS Ryan, MJ TI Acoustic competition in Physalaemus pustulosus, a differential response to calls of relative frequency SO ETHOLOGY LA English DT Article ID GRADED AGGRESSIVE CALLS; BLANCHARD CRICKET FROG; FEMALE MATE CHOICE; NEOTROPICAL FROG; TUNGARA FROG; SEXUAL SELECTION; SIZE AB The response of the male tungara frog (Physalaemus pustulosus) to conspecific whines of different frequencies was examined. In the first series of playback experiments (fixed frequency), three types of synthetic stimuli were used, corresponding to calls of high frequency (HFF; (x) over bar + 2 SD), mid-frequency (MFF; (x) over bar), and low frequency (LFF; (x) over bar - 2 SD) for the study population. In the second series of interactive playback experiments (relative frequency), whines of frequency relative to that of the male subject were used: male frequency + 2 SD (HRF), male frequency (MRF), and male frequency -2SD (LRF). In the fixed frequency experiments, male vocal response did not vary among treatments. However, in the relative frequency experiments, males responded with more whines, and above all, with more chucks, to stimuli of similar or higher frequency than to stimuli of lower frequency than their own. In other words, male vocal competition escalates when competitors have whines with similar or relatively higher frequencies to their own, but does not increase when competitors have call frequencies that are at the mean or higher for the population. This differential response might result from competition between males of different sizes, since the frequency of the whine and male size is significantly correlated. C1 CSIC, Museo Nacl Ciencias Nat, E-28006 Madrid, Spain. Smithsonian Trop Res Inst, Balboa, Panama. Univ Texas, Sect Integrat Biol, Austin, TX 78712 USA. RP Bosch, J (reprint author), CSIC, Museo Nacl Ciencias Nat, Jose Gutierrez Abascal 2, E-28006 Madrid, Spain. RI Bosch, Jaime/H-3042-2011; OI Bosch, Jaime/0000-0002-0099-7934 NR 20 TC 13 Z9 13 U1 0 U2 2 PU BLACKWELL WISSENSCHAFTS-VERLAG GMBH PI BERLIN PA KURFURSTENDAMM 57, D-10707 BERLIN, GERMANY SN 0179-1613 J9 ETHOLOGY JI Ethology PD OCT PY 2000 VL 106 IS 10 BP 865 EP 871 DI 10.1046/j.1439-0310.2000.00587.x PG 7 WC Psychology, Biological; Behavioral Sciences; Zoology SC Psychology; Behavioral Sciences; Zoology GA 366FL UT WOS:000089994100001 ER PT J AU Dolan, JR Perez, MT AF Dolan, JR Perez, MT TI Costs, benefits and characteristics of mixotrophy in marine oligotrichs SO FRESHWATER BIOLOGY LA English DT Article; Proceedings Paper CT Workshop on Plankton Population Dynamics: Food Web Interactions and Abiotic Constraints CY NOV, 1998 CL CONSTANCE, GERMANY DE ciliates; heterotroph; marine oligotrichs; microzooplankton; mixotrophy ID NORTHWEST MEDITERRANEAN-SEA; CILIATE STROMBIDIUM-CONICUM; SURFACE WATERS; PLANKTONIC SARCODINES; SUSPENSION-FEEDERS; LABOEA-STROBILA; GROWTH-RATES; CILIOPHORA; NANOPLANKTON; ABUNDANCE AB 1. Oligotrich ciliates are an important part of most marine plankton communities. Mixotrophic (chloroplast-sequestering) oligotrichs, a common component of marine oligotrich communities, obtain fixed carbon from both photosynthesis as well as the ingestion of particulate food. Mixotrophy, in general, is often considered an adaptation permitting exploitation of food-poor environments. We examined the hypothesis that, among oligotrichs, mixotrophs may be at a disadvantage relative to heterotrophs in food-rich conditions in a nutrient-enrichment experiment. We compared growth responses of mixotrophic and heterotrophic oligotrichs in natural communities from the N.W. Mediterranean Sea in microcosms with daily nutrient additions resulting in increases in nanoflagellates and Synechococcus populations. The results indicated that both mixotrophic and heterotrophic oligotrichs respond to prey increases with rapid growth (mu = 1.2 d(-1)). 2. To examine the hypothesis that the proportion of mixotrophic to heterotrophic oligotrichs changes with the trophic status of a system, increasing with oligotrophy, we examined data from a variety of marine systems. Across systems ranging in chlorophyll concentration from about 0.1 to 40 mug L-1, oligotrich cell concentrations are correlated with chlorophyll concentrations, and mixotrophs are a consistent component of oligotrich communities, averaging about 30% of oligotrich cell numbers. 3. We discuss the costs, benefits and possible uses of mixotrophy in marine oligotrichs and suggest that mixotrophy in marine oligotrichs is not closely linked to the exploitation of food-poor environments, but probably serves a variety of purposes. C1 Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. CNRS, ESA 7076, Marine Microbial Ecol Grp, Stn Zool, F-06230 Villefranche Sur Mer, France. RP Dolan, JR (reprint author), Smithsonian Environm Res Ctr, POB 28, Edgewater, MD 21037 USA. EM dolan@ccrv.obs-vlfr.fr RI Dolan, John/A-4513-2009 OI Dolan, John/0000-0002-9454-1355 NR 72 TC 41 Z9 47 U1 3 U2 13 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0046-5070 EI 1365-2427 J9 FRESHWATER BIOL JI Freshw. Biol. PD OCT PY 2000 VL 45 IS 2 BP 227 EP 238 DI 10.1046/j.1365-2427.2000.00659.x PG 12 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 369UZ UT WOS:000165086500011 ER PT J AU Li, JH Dijkstra, P Hymus, GJ Wheeler, RM Piastuch, WC Hinkle, CR Drake, BG AF Li, JH Dijkstra, P Hymus, GJ Wheeler, RM Piastuch, WC Hinkle, CR Drake, BG TI Leaf senescence of Quercus myrtifolia as affected by long-term CO2 enrichment in its native environment SO GLOBAL CHANGE BIOLOGY LA English DT Article DE carbon dioxide; chlorophyll; leaf senescence; nitrogen; Rubisco ID ELEVATED CARBON-DIOXIDE; PLANT SENESCENCE; ESTUARINE MARSH; GAS-EXCHANGE; NITROGEN; GROWTH; LEAVES; ACCLIMATION; RESPONSES; WHEAT AB The long-term effects of elevated (ambient plus 350 mu mol mol(-1)) atmospheric CO2 concentration (C-a) on the leaf senescence of Quercus myrtifolia Willd was studied in a scrub-oak community during the transition from autumn (December 1997) to spring (April 1998). Plants were grown in large open-top chambers at the Smithsonian CO2 Research Site, Merritt Island Wildlife Refuge, Cape Canaveral, Florida. Chlorophyll (a + b) concentration, Rubisco activity and N concentration decreased by 75%, 82%, and 52%, respectively, from December (1997) to April (1998) in the leaves grown at ambient C-a. In contrast, the leaves of plants grown at elevated C-a showed no significant decrease in chlorophyll (a + b) concentration or Rubisco activity, and only a 25% reduction in nitrogen. These results indicate that leaf senescence was delayed during this period at elevated C-a. Delayed leaf senescence in elevated C-a had important consequences for leaf photosynthesis. In elevated C-a the net photosynthetic rate of leaves that flushed in Spring 1997 (last year's leaves) and were 13 months old was not different from fully-expanded leaves that flushed in 1998, and were approximately 1 month old (current year's leaves). In ambient C-a the net photosynthetic rate of last year's leaves was 54% lower than for current year's leaves. When leaves were fully senesced, nitrogen concentration decreased to about 40% of the concentration in non-senesced leaves, in both CO2 treatments. In April, net photosynthesis was 97% greater in leaves grown in elevated C-a than in those grown at ambient. During the period when elevated C-a delayed leaf senescence, more leaves operating at higher photosynthetic rate would allow the ecosystem dominated by Q. myrtifolia to gain more carbon at elevated C-a than at ambient C-a. C1 Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. Natl Res Council, Kennedy Space Ctr, FL 32899 USA. NASA, Biomed Off, Kennedy Space Ctr, FL 32899 USA. Dynamac Corp, Kennedy Space Ctr, FL 32899 USA. RP Drake, BG (reprint author), Smithsonian Environm Res Ctr, POB 28, Edgewater, MD 21037 USA. NR 32 TC 22 Z9 23 U1 0 U2 4 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 1354-1013 J9 GLOB CHANGE BIOL JI Glob. Change Biol. PD OCT PY 2000 VL 6 IS 7 BP 727 EP 733 DI 10.1046/j.1365-2486.2000.00347.x PG 7 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 365CR UT WOS:000089931300002 ER PT J AU Shepard, MK Benner, LAM Ostro, SJ Harris, AW Rosema, KD Shapiro, II Chandler, JF Campbell, DB AF Shepard, MK Benner, LAM Ostro, SJ Harris, AW Rosema, KD Shapiro, II Chandler, JF Campbell, DB TI Radar observations of Asteroid 2100 Ra-Shalom SO ICARUS LA English DT Article DE asteroids; radar; surfaces, asteroids; asteroids, composition; asteroids, Ra-Shalom ID NEAR-EARTH ASTEROIDS; VENUS; ARECIBO AB We report Doppler-only (cw) radar observations of near-Earth Asteroid 2100 Ra-Shalom obtained at the Arecibo Observatory using a transmitter frequency of 2380 MHz (12.6 cm) on 1984 Aug. 18-22. Weighted and filtered sums of cw echoes achieve a maximum signal-to-noise ratio of 74 and cover the asteroid in rotation phase. A weighted sum of all cw spectra gives an opposite circular (OC) radar cross section of 1.13 +/- 0.40 km(2) and a circular polarization ratio of 0.31 +/- 0.02. Inversion of echo edge frequencies yields a convex hull with an elongation (maximum breadth/minimum breadth) of 1.15 +/- 0.03 and places a lower bound on the maximum pole-on dimension of 2.4 km/cos delta, where delta is the angle between the radar line-of-sight and the asteroid's apparent equator. Ra-Shalom has one of the least elongated pole-on silhouettes of the near-Earth asteroids for which similar shape information from radar observations is available. Ra-Shalom's effective diameter (diameter of a sphere with equal cross-sectional area) is constrained to a range of 2.4-3.6 km. We use a two-component radar scattering model to remove the "diffuse" contributions from Ra-Shalom's radar cross section and obtain a surface bulk density estimate of 1.1-3.3 g cm(-3). When compared with reported bulk densities and porosities of meteorites, our results are consistent with either: (1) a C-class asteroid with carbonaceous-chondritic composition, effective diameter 2.6-3.6 km, and surface porosity <70%; or (2) an S-class asteroid with ordinary-chondritic or stony-iron composition, effective diameter 2.4-2.6 km, and little or no surface regolith. Ra-Shalom's near-surface roughness appears to be globally heterogeneous. (C) 2000 Academic Press. C1 Bloomsburg Univ Penn, Dept Geog & Geosci, Bloomsburg, PA 17815 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Cornell Univ, Natl Astron & Ionosphere Ctr, Ithaca, NY 14853 USA. RP Shepard, MK (reprint author), Bloomsburg Univ Penn, Dept Geog & Geosci, Bloomsburg, PA 17815 USA. NR 29 TC 7 Z9 7 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD OCT PY 2000 VL 147 IS 2 BP 520 EP 529 DI 10.1006/icar.2000.6470 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 368NY UT WOS:000090125100014 ER PT J AU Wallace, HD AF Wallace, HD TI Inventing the Internet SO IEEE ANNALS OF THE HISTORY OF COMPUTING LA English DT Book Review C1 Smithsonian Inst, Natl Museum Amer Hist, Washington, DC 20560 USA. RP Wallace, HD (reprint author), Smithsonian Inst, Natl Museum Amer Hist, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1058-6180 J9 IEEE ANN HIST COMPUT JI IEEE Ann. Hist. Comput. PD OCT-DEC PY 2000 VL 22 IS 4 BP 66 EP 67 DI 10.1109/MAHC.2000.887994 PG 2 WC Computer Science, Theory & Methods; History & Philosophy Of Science SC Computer Science; History & Philosophy of Science GA 368XF UT WOS:000090142200012 ER PT J AU Barse, WP AF Barse, WP TI Ronquin, AMS dates, and the Middle Orinoco sequence SO INTERCIENCIA LA English DT Article DE Orinoco; arquelogy; ronquin; AMS DAtes; ceramic sequence AB The model of agricultural intensification and population expansion in the middle Orinoco River area, based on the introduction of maize at ca. 800 BC, is predicated on acceptance of early radiocarbon dates for the ceramic sequence developed for the Parmana area. However, accelerator mass spectroscopy (AMS) radiocarbon dates from the Ronquin site ceramics suggest that the sequence is much younger than hypothesized by several investigators. First millennium AMS dares reported herein argue that the dating of the Middle Orinoco sequence is in need of revision, thus leaving the introduction of maize into the region a more recent phenomenon that occurred well into the first millennium AD. C1 Smithsonian Inst, Washington, DC 20560 USA. URS Corp, San Francisco, CA 94111 USA. RP Barse, WP (reprint author), 1026 Union Ave, Baltimore, MD 21211 USA. NR 18 TC 3 Z9 3 U1 0 U2 0 PU INTERCIENCIA PI CARACAS PA APARTADO 51842, CARACAS 1050A, VENEZUELA SN 0378-1844 J9 INTERCIENCIA JI Interciencia PD OCT PY 2000 VL 25 IS 7 BP 337 EP 341 PG 5 WC Ecology SC Environmental Sciences & Ecology GA 364VF UT WOS:000089913200004 ER PT J AU Rand, H AF Rand, H TI Who was Rumpelstiltskin? SO INTERNATIONAL JOURNAL OF PSYCHOANALYSIS LA English DT Article AB The author describes the way in which Rumpelstiltskin has perplexed and enthralled readers since the brothers Grimm recover ed the tale fr om the realm of folklore. In standard translation, the story now lives in a fixed literary form and, consequently, in the imagination of every child who has ever heard or read the story-virtually every person in the English-speaking world. Therefore, deeply rooted in childhood experiences, Rumpelstiltskin can be expected to appear in analysis, and he does. The compelling central character is the title figure, Rumpelstiltskin, whose name and actions tell us who he is and what he was intended to 'mean'-especially to his contemplated audience. The original narrators of and listeners to this tale were female visitors to the evening spinning chamber (Spinnstube), where women gathered and told tales to amuse themselves to ward off sleep while they spun. The butt of this story is male impotence and bluster, and the key to the story's meaning arises from matching the etymological roots of the central character's name with his actions as they appear philologically and psychoanalytically. C1 Smithsonian Inst, Natl Museum Amer Hist, Washington, DC 20560 USA. RP Rand, H (reprint author), Smithsonian Inst, Natl Museum Amer Hist, Washington, DC 20560 USA. NR 25 TC 2 Z9 2 U1 0 U2 1 PU INST PSYCHO-ANALYSIS PI LONDON PA 63 NEW CAVENDISH STREET, LONDON W1M 7RD, ENGLAND SN 0020-7578 J9 INT J PSYCHOANAL JI Int. J. Psychoanal. PD OCT PY 2000 VL 81 BP 943 EP 962 DI 10.1516/0020757001600309 PN 5 PG 20 WC Psychology, Psychoanalysis SC Psychology GA 370CP UT WOS:000165105500006 PM 11109578 ER PT J AU Gordon, VD Nathan, ES Apponi, AJ McCarthy, MC Thaddeus, P Botschwina, P AF Gordon, VD Nathan, ES Apponi, AJ McCarthy, MC Thaddeus, P Botschwina, P TI Structures of the linear silicon carbides SiC4 and SiC6: Isotopic substitution and Ab Initio theory SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CORRELATED MOLECULAR CALCULATIONS; GAUSSIAN-BASIS SETS; VIBRATIONAL FREQUENCIES; SPECTROSCOPIC CONSTANTS; ROTATIONAL SPECTRUM; LASER SPECTROSCOPY; CLUSTERS; GEOMETRY; C-5 AB The structures of two linear silicon carbides, SiC4 and SiC6, have been determined by a combination of isotopic substitution and large-scale coupled-cluster ab initio calculations, following detection of all of the singly substituted isotopic species in a supersonic molecular beam with a Fourier transform microwave spectrometer. Rotational constants obtained by least-squares fitting transition frequencies were used to derive experimental structures; except for those nearest the center of mass, individual bond lengths for both chains have an error of less than 0.008 Angstrom. Accurate equilibrium structures were derived by converting the experimental rotational constants to equilibrium constants using the vibration-rotation coupling constants from coupled-cluster calculations, including connected triple substitutions. Equilibrium dipole moments and harmonic vibrational frequencies were also calculated for both chains. On the basis of the calculated vibration-rotation and l-type doubling constants, weak rotational satellites from a low-lying vibrational state of SiC4 were assigned to v(6), a bending mode calculated to lie about 205 cm(-1) above the ground state. A recommended ab initio equilibrium structure for SiC8 has also been established. (C) 2000 American Institute of Physics. [S0021-9606(00)01537-3]. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Univ Gottingen, Inst Phys Chem, D-37077 Gottingen, Germany. RP Gordon, VD (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI McCarthy, Michael/0000-0001-9142-0008 NR 37 TC 50 Z9 50 U1 0 U2 13 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 1 PY 2000 VL 113 IS 13 BP 5311 EP 5320 AR PII [S0021-9606(00)01537-3] DI 10.1063/1.1290126 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 354TC UT WOS:000089344900027 ER PT J AU Paciorek, CJ Condit, R Hubbell, SP Foster, RB AF Paciorek, CJ Condit, R Hubbell, SP Foster, RB TI The demographics of resprouting in tree and shrub species of a moist tropical forest SO JOURNAL OF ECOLOGY LA English DT Article DE demography; forest dynamics; mortality; sprouting; vegetative regeneration ID RAIN-FOREST; PUERTO-RICO; HURRICANE DAMAGE; NEOTROPICAL FOREST; PHYSICAL DAMAGE; SOUTHEAST TEXAS; BARRO-COLORADO; MONTANE FOREST; MORTALITY; RECOVERY AB 1 Individuals of many woody plant species have the ability to respond to damage which causes removal of the crown by producing new branches (sprouts) along the remaining stem. Resprouting by woody plants has received little attention in relatively undisturbed tropical forest. 2 To assess the importance of resprouting for forest dynamics, we estimated resprouting rates and mortality rates of resprouted individuals for the forest as a whole and for individual species in a 50-ha permanent plot in tropical moist forest on Barro Colorado Island, Panama. We tested for differences between species and asked whether the differences were related to phylogeny, growth form or shade tolerance. 3 Among individuals not known to have resprouted previously, we estimate that the annual rate of resprouting is 1.7% for individuals in both small and large size classes (1-9.9 cm d.b.h. and greater than or equal to 10 cm d.b.h.). For small and large individuals, respectively, annual mortality of previously undamaged individuals is 2.2% and 1.5%, while that of resprouted individuals is 9.6% and 10.3%. This resulted in survival of 62% of resprouted individuals over 5 years, compared to 90% survival among individuals not known to have resprouted recently. 4 Resprouting rates varied by species and family, but little between growth forms. Species in the families Lauraceae and Piperaceae had high rates of resprouting. Resprouting was common across the spectrum of shade tolerance. 5 Damage to woody forest plants on Barro Colorado Island is frequent, and many species are able to respond by resprouting. Resprouting ability may be an important life history characteristic of woody species on BCI, with individuals experiencing both increases and decreases in size. C1 Duke Univ, Dept Bot, Durham, NC 27708 USA. Smithsonian Trop Res Inst, Unit 948, APO, AA 34002 USA. Princeton Univ, Dept Ecol Evolut & Behav, Princeton, NJ 08544 USA. Field Museum Nat Hist, Dept Bot, Chicago, IL 60605 USA. RP Paciorek, CJ (reprint author), Carnegie Mellon Univ, Dept Stat, 232 Baker Hall, Pittsburgh, PA 15213 USA. NR 50 TC 72 Z9 80 U1 3 U2 8 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0022-0477 J9 J ECOL JI J. Ecol. PD OCT PY 2000 VL 88 IS 5 BP 765 EP 777 DI 10.1046/j.1365-2745.2000.00494.x PG 13 WC Plant Sciences; Ecology SC Plant Sciences; Environmental Sciences & Ecology GA 363WE UT WOS:000089860000004 ER PT J AU Allen, LA Habbal, SR Li, X AF Allen, LA Habbal, SR Li, X TI Thermal coupling of protons and neutral hydrogen with anisotropic temperatures in the fast solar wind SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID POLAR CORONAL HOLES; ION-CYCLOTRON WAVES; ALFVEN WAVES; TRANSITION REGION; VELOCITY DISTRIBUTIONS; RESONANT ACCELERATION; PLASMA OBSERVATIONS; PHYSICAL-PROPERTIES; FLOW PROPERTIES; MAGNETIC-FIELD AB The thermal coupling between the neutral hydrogen and protons in the inner corona is explored by extending the study of Alien ct al. [1998] to include anisotropic proton temperature to determine what the neutral hydrogen Ly alpha spectral line measurements reveal about the proton temperature, temperature anisotropy, and outflow Velocity in the fast solar wind. The anisotropic proton temperature is produced by ion cyclotron resonant interaction of protons with high-frequency waves, produced by a nonlinear cascade at the Kolmogorov dissipation rate from dominant lower-frequency Alfven waves. As a result of the coupling between the respective parallel and perpendicular components of the neutral hydrogen and proton temperatures, a greater temperature anisotropy in the neutral hydrogen develops as compared to the case when the proton temperature is isotropic. The neutral hydrogen and proton effective temperatures (T-e (f) (f) ), incorporating: both random and wave motions of the particles, and outflow velocities: are comparable below similar to 3 R-s. Neutral hydrogen and anisotropy ratios, T-H (e f f )/T-parallel to, similar to 4 below 3 R-s are readily attained, in agreement with observations. Below similar to 3 R-s, these reflect the proton anisotropy ratio. For plasma conditions typical of the fast solar wind, these results imply that the measured Ly alpha spectral line profiles, from which the neutral hydrogen temperature, anisotropy ratio, and outflow velocity are inferred, are equivalent to measurements of protons below similar to 3 R-s. Beyond this distance the width of the measured Ly alpha spectral lines provides a lower limit to the proton effective temperature and temperature anisotropy in the inner corona. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Harvard Smithsonian Ctr Astrophys, 60 Garden St,MS-10, Cambridge, MA 02138 USA. EM lallen@cfa.harvard.edu; shabbal@cfa.harvard.edu; xli@cfa.harvard.edu NR 57 TC 13 Z9 13 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD OCT 1 PY 2000 VL 105 IS A10 BP 23123 EP 23134 DI 10.1029/1999JA000437 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 359UN UT WOS:000089630600014 ER PT J AU Lundeberg, PK AF Lundeberg, PK TI Canada's navy: The first century SO JOURNAL OF MILITARY HISTORY LA English DT Book Review C1 Smithsonian Inst, Washington, DC 20560 USA. RP Lundeberg, PK (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SOC MILITARY HISTORY PI LEXINGTON PA C/O VIRGINIA MILITARY INST, GEORGE C MARSHALL LIBRARY, LEXINGTON, VA 24450-1600 USA SN 0899-3718 J9 J MILITARY HIST JI J. Mil. Hist. PD OCT PY 2000 VL 64 IS 4 BP 1182 EP 1184 DI 10.2307/2677304 PG 3 WC History SC History GA 359TU UT WOS:000089628800043 ER PT J AU Doherty, AC Vant, KMD Ball, GH Christensen, N Leonhardt, R AF Doherty, AC Vant, KMD Ball, GH Christensen, N Leonhardt, R TI Momentum distributions for the quantum delta-kicked rotor with decoherence SO JOURNAL OF OPTICS B-QUANTUM AND SEMICLASSICAL OPTICS LA English DT Article DE quantum chaos; decoherence; laser-cooled atoms ID DYNAMICAL LOCALIZATION; SPONTANEOUS EMISSION; CHAOS; ATOMS; NOISE; MOTION AB We discuss the theoretical description and numerical simulation of the effect of noise and environmental coupling on the momentum distribution of the quantum delta -kicked rotor in recent atom optics experiments. We investigate the transition between exponentially localized and more nearly Gaussian momentum distributions and compare our simulations with existing experimental results. C1 Univ Auckland, Dept Phys, Auckland, New Zealand. MIT, Dept Phys, Cambridge, MA 02139 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Carleton Coll, Northfield, MN 55057 USA. CALTECH, Norman Bridge Lab Phys 12 33, Pasadena, CA 91125 USA. RP Doherty, AC (reprint author), Univ Auckland, Dept Phys, Private Bag 92019, Auckland, New Zealand. RI Doherty, Andrew/D-1816-2010 OI Doherty, Andrew/0000-0002-8069-7754 NR 22 TC 14 Z9 14 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1464-4266 J9 J OPT B-QUANTUM S O JI J. Opt. B-Quantum Semicl. Opt. PD OCT PY 2000 VL 2 IS 5 BP 605 EP 611 DI 10.1088/1464-4266/2/5/307 PG 7 WC Optics; Physics, Applied SC Optics; Physics GA 372WQ UT WOS:000165257400009 ER PT J AU Sigleo, AC Neale, PJ Spector, AM AF Sigleo, AC Neale, PJ Spector, AM TI Phytoplankton pigments at the Weddell-Scotia confluence during the 1993 austral spring SO JOURNAL OF PLANKTON RESEARCH LA English DT Article ID PERFORMANCE LIQUID-CHROMATOGRAPHY; ICE-EDGE ZONE; SOUTHERN-OCEAN; THALASSIOSIRA-PSEUDONANA; ULTRAVIOLET-RADIATION; DEGRADATION PRODUCTS; RAPID-DETERMINATION; B RADIATION; BLOOM; SEA AB During a 1995 austral spring cruise, a complex biomass was encountered near South Orkney Island that ranged from a low-biomass, Chaetoceros tortissimus assemblage south of the front towards the ice edge, to a high-biomass, Thalassiosira gravida-dominated assemblage at the northern edge. The maximum levels of chlorophyll (Chl) a (up to 6 mg m(-3)) were higher than those observed in previous high-performance liquid chromatography-based studies of pigments in the pelagic Southern Ocean. The non-photosynthetic pigment chlorophyllide a comprised up to 75% of the chlorophyllous pigments in the southern assemblage, but < 5% in the northern assemblage. Concentrations of the xanthophylls diadinoxanthin (DD) and diatoxanthin (DT), used as indicators of mean irradiance, indicated low-light-adapted populations. Low-light DD + DT/Chl a ratios in surface waters indicated that vertical mixing limited phytoplankton residence time in the near-surface layer, and thus limited exposure to maximum irradiance. Deck incubations of natural assemblages indicated that the dark epoxidation reaction (i.e. the return of DT to DD) was a two-step reaction with the initial rate being more rapid (t(1/2) = 9.5 min) than the second (t(1/2) = 55 min). Fucoxanthin, a major diatom pigment, was more stable chemically in the water column than Chi a, and the vertical profiles of fucoxanthin followed those of chlorophyllide a in some cases. The formation and apparent stability of chlorophyllide a and fucoxanthin are important considerations when estimating photosynthetically active biomass over large regions of the ocean. C1 US EPA, Western Ecol Div, Newport, OR 97365 USA. Oregon State Univ, Coll Ocean & Atmospher Sci, Newport, OR 97365 USA. Smithsonian Environm Res Ctr, Edgewater, MD 20715 USA. RP Sigleo, AC (reprint author), US EPA, Western Ecol Div, 2111 SE Marine Sci Dr, Newport, OR 97365 USA. RI Neale, Patrick/A-3683-2012 NR 46 TC 9 Z9 9 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0142-7873 J9 J PLANKTON RES JI J. Plankton Res. PD OCT PY 2000 VL 22 IS 10 BP 1989 EP 2006 DI 10.1093/plankt/22.10.1989 PG 18 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 363GU UT WOS:000089827800012 ER PT J AU Pelaez, J Lorenzini, EC Lopez-Rebollal, O Ruiz, M AF Pelaez, J Lorenzini, EC Lopez-Rebollal, O Ruiz, M TI A new kind of dynamic instability in electrodynamic tethers SO JOURNAL OF THE ASTRONAUTICAL SCIENCES LA English DT Article; Proceedings Paper CT AAS/AIAA 10th Space Flight Mechanics Meeting CY JAN 23-26, 2000 CL CLEARWATER, FLORIDA SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB Simulation of the dynamics of an electrodynamic tether on a circular inclined orbit shows a very complex motion driven by the electrodynamic forces acting on the conductive tether. These forces depend on the current flowing in the wire, the Earth magnetic field, the orbital velocity and the tether position. In this paper we use a simple model to describe the dynamic effects of these forces. The tether is modeled as a rigid rod with point masses at the ends. We also adopt a non-tilted dipole model for the Earth magnetic field, and we assume that the tether current is constant. When the current is null, the system has a stable equilibrium position with the tether aligned along the local vertical. When the current is different from zero, a periodic motion appears. A nonlinear analysis of the motion shows that the periodic solutions are always unstable (within the limitation of the model considered in the paper). The physical reason for the instability is that the electrodynamic forces pump energy continually into the system. The net energy increase per orbit for the periodic solution (or state space trajectory) is zero. However, any nonperiodic trajectory in its neighborhood has a positive net energy flux per orbit so that after several orbits the in-plane libration becomes a rotation. The mechanism responsible for this instability depends on the orbital inclination. Unlike other destabilizing mechanisms found in electrodynamic tethers, this one is present in any kind of tether system with either a flexible or a rigid tether, operating in the generator or thruster mode and utilizing a bare tether or a large spherical termination to collect the ionospheric electrons. The instability described in this paper is independent of the presence of resonant force components that may be generated by the magnetic and plasma fields. C1 Univ Politecn Madrid, ETSI Aeronaut, E-28040 Madrid, Spain. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Pelaez, J (reprint author), Univ Politecn Madrid, ETSI Aeronaut, Pza Cardenal Cisneros 3, E-28040 Madrid, Spain. OI PELAEZ ALVAREZ, JESUS/0000-0001-9755-1674 NR 13 TC 56 Z9 57 U1 1 U2 5 PU AMER ASTRONAUTICAL SOC PI SPRINGFIELD PA 6352 ROLLING MILL PLACE SUITE 102, SPRINGFIELD, VA 22152 USA SN 0021-9142 J9 J ASTRONAUT SCI JI J. Astronaut. Sci. PD OCT-DEC PY 2000 VL 48 IS 4 BP 449 EP 476 PG 28 WC Engineering, Aerospace SC Engineering GA 456PT UT WOS:000170092000002 ER PT J AU Condit, R Watts, K Bohlman, SA Perez, R Foster, RB Hubbell, SP AF Condit, R Watts, K Bohlman, SA Perez, R Foster, RB Hubbell, SP TI Quantifying the deciduousness of tropical forest canopies under varying climates SO JOURNAL OF VEGETATION SCIENCE LA English DT Article DE climate gradient; deciduousness; phenology; tropical forest ID PLANT FUNCTIONAL TYPES; NEOTROPICAL FOREST; PHENOLOGY; TREES; DROUGHT; CONSEQUENCES; EVERGREEN; PATTERNS; IMPACT AB Deciduousness is an important functional attribute of tropical trees, reflecting climatic conditions. Precisely quantifying and mapping deciduousness in tropical forests will be necessary for calibrating remote sensing images which attempt to assess canopy properties such as carbon cycling, productivity, or chlorophyll content. We thus set out to assess the degree of canopy deciduousness in three moist, semi-deciduous tropical forests in central Panama. One site is a 6-ha research plot near the Atlantic coast of Panama, where rainfall is 2830 mm/yr. The second site is a 50-ha plot on Barro Colorado Island, near the center of the isthmus of Panama, where rainfall is 2570 mm/yr, and the final site is a 4-ha plot near the Pacific coast of Panama, where rainfall is 2060 mm/yr. At each site, a random sample of trees from all canopy species (those with individuals greater than or equal to 30 cm DBH) were visited and scored for deciduousness three times during the 1997 dry season. The estimated peak fraction of deciduous individuals in the canopy at the wetter site was 4.8%, at the intermediate site, 6.3%, and at the drier site, 24.3%. The estimated fraction of crown area deciduous peaked at 3.6%, 9.7%, and 19.1% at the wet, medium, and dry sites respectively. The percentage of canopy species that was deciduous -14%, 28%, and 41%-was much higher than the percentage of deciduous individuals, because not all individuals of deciduous species were deciduous. During the 1999 dry season, every individual of all the deciduous species was visited at the two drier sites, and the total number of deciduous trees observed closely matched the estimated numbers based on the smaller 1997 samples. C1 Smithsonian Trop Res Inst, Ctr Trop Forest Sci, Unit 0948, APO, AA 34002 USA. Southampton Coll, Southampton, NY 11968 USA. Univ Washington, Coll Forest Resources, Seattle, WA 98192 USA. Field Museum Nat Hist, Dept Bot, Chicago, IL 60605 USA. Univ Georgia, Dept Bot, Athens, GA 30602 USA. RP Condit, R (reprint author), Smithsonian Trop Res Inst, Ctr Trop Forest Sci, Unit 0948, APO, AA 34002 USA. NR 35 TC 62 Z9 75 U1 1 U2 25 PU OPULUS PRESS UPPSALA AB PI UPPSALA PA BOX 25137, S 752 25 UPPSALA, SWEDEN SN 1100-9233 J9 J VEG SCI JI J. Veg. Sci. PD OCT PY 2000 VL 11 IS 5 BP 649 EP 658 DI 10.2307/3236572 PG 10 WC Plant Sciences; Ecology; Forestry SC Plant Sciences; Environmental Sciences & Ecology; Forestry GA 389TD UT WOS:000166253100005 ER PT J AU Murray, S Monfort, SL Ware, L McShea, WJ Bush, M AF Murray, S Monfort, SL Ware, L McShea, WJ Bush, M TI Anesthesia in female white-tailed deer using Telazol (R) and xylazine SO JOURNAL OF WILDLIFE DISEASES LA English DT Article DE anesthesia; ketamine; Odocoileus virginianus; Telazol (R); white-tailed deer; xylazine; yohimbine ID MULE DEER; TOLAZOLINE HYDROCHLORIDE; KETAMINE-HYDROCHLORIDE; YOHIMBINE; IMMOBILIZATION; ANTAGONISM; REVERSAL AB Thirty two free-ranging female white-tailed deer (Odocoileus virginianus) were anesthesized with varying Telazol(R) and xylazine HCl combinations in Front Royal (Virginia, USA) between August 1992 and September 1992. All animals were caught in baited box traps, manually restrained, and hand injected with a combination of Telazol and xylazine administered intramuscularly. Deer received mean +/- SE dosages of 2.53 +/- 0.16 mg/kg Telazol and 0.69 +/- 0.05 mg/kg of zylazine. These dosages achieved a rapid and effective anesthetic plane for short-term procedures such as weighing, blood collection, and translocation. Eight of 32 deer (25%) required an intravenous (i.v.) supplement of ketamine HCl (100 mg) to maintain a safe plane of anesthesia. Ketamine supplementation provided an average of 11.8 +/- 2.0 min additional safe handling. Satisfactory reversals were achieved in all deer by administering yohimbine HCl 16 mg i.v. (dose range, 0.22 to 0.48 mg/kg) to all animals. C1 Natl Zool Pk, Conservat & Res Ctr, Front Royal, VA 22630 USA. Ft Worth Zoo, Dept Anim Hlth, Ft Worth, TX 76110 USA. RP Murray, S (reprint author), Natl Zool Pk, Conservat & Res Ctr, 1500 Remount Rd, Front Royal, VA 22630 USA. NR 15 TC 20 Z9 21 U1 0 U2 1 PU WILDLIFE DISEASE ASSN, INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 USA SN 0090-3558 J9 J WILDLIFE DIS JI J. Wildl. Dis. PD OCT PY 2000 VL 36 IS 4 BP 670 EP 675 PG 6 WC Veterinary Sciences SC Veterinary Sciences GA 371GK UT WOS:000165170300006 PM 11085428 ER PT J AU Lovette, IJ Bermingham, E AF Lovette, IJ Bermingham, E TI c-mos variation in songbirds: Molecular evolution, phylogenetic implications, and comparisons with mitochondrial differentiation SO MOLECULAR BIOLOGY AND EVOLUTION LA English DT Article DE c-mos; mitochondrial DNA; Passeriformes; phylogeny; substitution rates ID DENDROICA WARBLERS; TREE TOPOLOGIES; PROTO-ONCOGENE; DNA; BIRDS; SEQUENCE; VERTEBRATES; DIVERGENCES; SPECIATION; PASSERINE AB Nucleotide sequences from the c-mos proto-oncogene have previously been used to reconstruct the phylogenetic relationships between distantly related vertebrate taxa. To explore c-mos variation at shallower levels of avian divergence, we compared c-mos sequences from representative passerine taxa that span a range of evolutionary differentiation, from basal passerine lineages to closely allied genera. Phylogenetic reconstructions based on these c-mos sequences recovered topologies congruent with previous DNA-DNA hybridization-based reconstructions, with many nodes receiving high support, as indicated by bootstrap and reliability values. One exception was the relationship of Acanthisitta to the remaining passerines, where the c-mos-based searches indicated a three-way polytomy involving the Acanthisitta lineage and the suboscine and oscine passerine clades. We also compared levels of c-mos and mitochondrial differentiation across eight oscine passerine taxa and found that c-mos nucleotide substitutions accumulate at a rate similar to that of transversion substitutions in mitochondrial protein-coding genes. These comparisons suggest that nuclear-encoded loci such as c-mos provide a temporal window of phylogenetic resolution that overlaps the temporal range where mitochondrial protein-coding sequences have their greatest utility and that c-mos substitutions and mtDNA transversions can serve as complementary, informative, and independent phylogenetic markers for the study of avian relationships. C1 Smithsonian Trop Res Inst, Balboa, Panama. Univ Penn, Dept Biol, Philadelphia, PA 19104 USA. RP Lovette, IJ (reprint author), San Francisco State Univ, Dept Biol, Ctr Trop Res, 1600 Holloway Ave, San Francisco, CA 94132 USA. EM ilovette@sas.upenn.edu RI Lovette, Irby/P-3477-2014 NR 49 TC 30 Z9 37 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0737-4038 J9 MOL BIOL EVOL JI Mol. Biol. Evol. PD OCT PY 2000 VL 17 IS 10 BP 1569 EP 1577 PG 9 WC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity GA 360MH UT WOS:000089671400014 PM 11018162 ER PT J AU Merloni, A Di Matteo, T Fabian, AC AF Merloni, A Di Matteo, T Fabian, AC TI Magnetic flares and the optical variability of the X-ray transient XTE J1118+480 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE accretion, accretion discs; magnetic fields; radiation mechanisms : thermal; binaries : general; stars : individual : XTE J1118+480 ID ADVECTION-DOMINATED ACCRETION; QUASI-PERIODIC OSCILLATION; ACTIVE GALACTIC NUCLEI; BLACK-HOLES; CORONAE; GX339-4; DISKS; FREQUENCIES; PRECESSION; BINARIES AB The simultaneous presence of a strong quasi-periodic oscillation, of period similar to 10 s, in the optical and X-ray light curves of the X-ray transient XTE J1118+480 suggests that a significant fraction of the optical flux originates from the inner part of the accretion flow, where most of the X-rays are produced. We present a model of magnetic flares in an accretion disc corona where thermal cyclo-synchrotron emission contributes significantly to the optical emission, while the X-rays are produced by inverse Compton scattering of the soft photons produced by dissipation in the underlying disc and by the synchrotron process itself. Given the observational constraints, we estimate the values for the coronal temperature, optical depth and magnetic field intensity, as well as the accretion rate for the source. Within our model we predict a correlation between optical and hard X-ray variability and an anticorrelation between optical and soft X-rays. We also expect optical variability on flaring time-scales (similar to tens of ms), with a power-density spectrum similar to that observed in the X-ray band. Finally, we use both the available optical/extreme-ultraviolet/X-ray spectral energy distribution and the low-frequency time variability to discuss limits on the inner radius of the optically thick disc. C1 Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Merloni, A (reprint author), Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England. RI Di Matteo, Tiziana/O-4762-2014 OI Di Matteo, Tiziana/0000-0002-6462-5734 NR 36 TC 40 Z9 41 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD OCT PY 2000 VL 318 IS 1 BP L15 EP L19 DI 10.1046/j.1365-8711.2000.03943.x PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 363VB UT WOS:000089857400004 ER PT J AU Ward, DC AF Ward, DC TI Republic of letters: The American intellectual community, 1775-1865 SO PENNSYLVANIA MAGAZINE OF HISTORY AND BIOGRAPHY LA English DT Book Review C1 Smithsonian Inst, Washington, DC 20560 USA. RP Ward, DC (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU HISTORICAL SOC PA PI PHILADELPHIA PA 1300 LOCUST ST, PHILADELPHIA, PA 19107 USA SN 0031-4587 J9 PENN MAG HIST BIOG JI Pa. Mag. Hist. Biogr. PD OCT PY 2000 VL 124 IS 4 BP 572 EP 573 PG 2 WC History SC History GA 371MN UT WOS:000165182900012 ER PT J AU Estes, RD Sanmartin, JR AF Estes, RD Sanmartin, JR TI Cylindrical Langmuir probes beyond the orbital-motion-limited regime SO PHYSICS OF PLASMAS LA English DT Article ID TETHERS AB The current I to a cylindrical probe at rest in an unmagnetized plasma, with probe bias highly positive, is determined. The way I lags behind the orbital-motion-limited (OML) current, I(OML)proportional to R, as the radius R exceeds the maximum radius for the OML regime to hold, is of interest for space-tether applications. The ratio I/I-OML is roughly a decreasing function of R/lambda(De)-R-max/lambda(De), which is independent of bias, with lambda(De) the electron Debye length and R-max/lambda(De) roughly an increasing function of the temperature ratio, T-i/T-e. The dependence of current on ion energy is used to discuss the effect of probe motion through the plasma, a case applying to tethers in low orbit. (C) 2000 American Institute of Physics. [S1070-664X(00)00210-X]. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Politecn Madrid, Escuela Tecn Super Ingn Aeronaut, E-28040 Madrid, Spain. RP Estes, RD (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 13 TC 28 Z9 28 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD OCT PY 2000 VL 7 IS 10 BP 4320 EP 4325 DI 10.1063/1.1288400 PG 6 WC Physics, Fluids & Plasmas SC Physics GA 353QX UT WOS:000089287900057 ER PT J AU Thompson, FC Zumbado, MA AF Thompson, FC Zumbado, MA TI Flower flies of the subgenus Ocyptamus (Mimocalla Hull) (Diptera : Syrphidae) SO PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON LA English DT Article DE neotropical; key AB The subgenus Ocyptamus (Mimocalla) is revised. Ocyptamus (Mimocalla) tristani Zumbado, new species, is described and two new synonyms are proposed (Salpingogaster flukei Curran 1941 and Baccha polista Hull 1943 = Baccha bonariensis Brethes 1905). A key to the species, along with synonymies, descriptions, distributions, and figures for all species are given. C1 Smithsonian Inst, Natl Museum Amer Hist, Systemat Entomol Lab, PSI,Agr Res Serv,USDA, Washington, DC 20560 USA. RP Thompson, FC (reprint author), Smithsonian Inst, Natl Museum Amer Hist, Systemat Entomol Lab, PSI,Agr Res Serv,USDA, Washington, DC 20560 USA. EM cthompso@sel.barc.usda.gov; mzumbado@inbio.ac.cr NR 41 TC 14 Z9 16 U1 0 U2 1 PU ENTOMOL SOC WASHINGTON PI WASHINGTON PA SMITHSONIAN INSTITUTION DEPT ENTOMOLOGY, WASHINGTON, DC 20560 USA SN 0013-8797 J9 P ENTOMOL SOC WASH JI Proc. Entomol. Soc. Wash. PD OCT PY 2000 VL 102 IS 4 BP 773 EP 793 PG 21 WC Entomology SC Entomology GA 367GG UT WOS:000090052900001 ER PT J AU Gagne, RJ Blanco-Metzler, H Etienne, J AF Gagne, RJ Blanco-Metzler, H Etienne, J TI A new neotropical species of Clinodiplosis (Diptera : Cecidomyiidae), an important new pest of cultivated peppers (Capsicum spp.: Solanaceae) SO PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON LA English DT Article DE gall midge; sweet pepper; hot pepper AB A new species of cecidomyiid, Clinodiplosis capsici Gagne, is reported from cultivated sweet and hot pepper in Costa Rica, Guadeloupe, and French Guiana where it appears to have potential as a serious pest. Adults, pupae, and larvae are described, illustrated, and compared to other Clinodiplosis species. C1 Smithsonian Inst, Natl Museum Amer Hist, Systemat Entomol Lab, PSI,Agr Res Serv,USDA, Washington, DC 20560 USA. RP Gagne, RJ (reprint author), Smithsonian Inst, Natl Museum Amer Hist, Systemat Entomol Lab, PSI,Agr Res Serv,USDA, Washington, DC 20560 USA. NR 4 TC 1 Z9 2 U1 0 U2 0 PU ENTOMOL SOC WASHINGTON PI WASHINGTON PA SMITHSONIAN INSTITUTION DEPT ENTOMOLOGY, WASHINGTON, DC 20560 USA SN 0013-8797 J9 P ENTOMOL SOC WASH JI Proc. Entomol. Soc. Wash. PD OCT PY 2000 VL 102 IS 4 BP 831 EP 837 PG 7 WC Entomology SC Entomology GA 367GG UT WOS:000090052900005 ER PT J AU Woodley, NE AF Woodley, NE TI A new Afrotropical species of Allognosta Osten Sacken (Diptera : Stratiomyidae) SO PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON LA English DT Article DE Beridinae; Tanzania; Malawi AB Allognosta njombe, new species, is described from localities around the north end of Lake Nyassa in Tanzania (type locality) and Malawi. A key to the four known species of Afrotropical Allognosta is provided. Additional locality records are given for A. stuckenbergae Lindner and A. tessmanni Enderlein. C1 Smithsonian Inst, Natl Museum Amer Hist, Systemat Entomol Lab, PSI,Agr Res Serv,US Dept Agr, Washington, DC 20560 USA. RP Woodley, NE (reprint author), Smithsonian Inst, Natl Museum Amer Hist, Systemat Entomol Lab, PSI,Agr Res Serv,US Dept Agr, Washington, DC 20560 USA. RI Woodley, Norman/M-6160-2014 NR 5 TC 0 Z9 0 U1 0 U2 0 PU ENTOMOL SOC WASHINGTON PI WASHINGTON PA SMITHSONIAN INSTITUTION DEPT ENTOMOLOGY, WASHINGTON, DC 20560 USA SN 0013-8797 J9 P ENTOMOL SOC WASH JI Proc. Entomol. Soc. Wash. PD OCT PY 2000 VL 102 IS 4 BP 924 EP 928 PG 5 WC Entomology SC Entomology GA 367GG UT WOS:000090052900016 ER PT J AU Macintyre, IG Prufert-Bebout, L Reid, RP AF Macintyre, IG Prufert-Bebout, L Reid, RP TI The role of endolithic cyanobacteria in the formation of lithified laminae in Bahamian stromatolites SO SEDIMENTOLOGY LA English DT Article DE endolithic cyanobacteria; lithification; micritization; stromatolites ID MODERN MARINE STROMATOLITES; MICROBIAL MATS; SUBTIDAL STROMATOLITES; EXUMA-CAYS; PRESERVATION; REEF AB The microboring activity of endolithic cyanobacteria plays a major role in the formation of the dominant lithified laminae in modern marine stromatolites in the Exuma Gays, Bahamas. These stromatolites are composed primarily of fine-grained carbonate sand that is trapped and bound by the filamentous cyanobacteria Schizothrix sp.. Periodic introduction of coccoid endolithic cyanobacteria Solentia sp. during hiatuses in stromatolite growth associated with very low rates of sedimentation results in the formation of lithified horizons, 200-1000 mum thick. These layers consist of micritized grains that are welded together at point contacts. The micritization is caused by extensive microboring and carbonate precipitation within boreholes concurrent with endolithic activity. Grain welding occurs when boreholes cross from one grain to another at point contacts. Thus, microboring destroys original grain textures but, at the same time, plays a constructional role in stromatolite growth by forming lithified layers of welded grains; These lateral bands of fused carbonate grains help to stabilize and preserve the stromatolite deposits. C1 Natl Museum Nat Hist, Dept Paleobiol, Smithsonian Inst, Washington, DC 20560 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. RP Macintyre, IG (reprint author), Natl Museum Nat Hist, Dept Paleobiol, Smithsonian Inst, NHB-125, Washington, DC 20560 USA. NR 26 TC 88 Z9 92 U1 1 U2 7 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0037-0746 J9 SEDIMENTOLOGY JI Sedimentology PD OCT PY 2000 VL 47 IS 5 BP 915 EP 921 DI 10.1046/j.1365-3091.2000.00327.x PG 7 WC Geology SC Geology GA 371CQ UT WOS:000165160700001 ER PT J AU Holmes, WC Pruski, JF AF Holmes, WC Pruski, JF TI New species of Mikania (Compositae : Eupatorieae) from Ecuador and Peru SO SYSTEMATIC BOTANY LA English DT Article AB Mikania palmata and Mikania wurdackii, endemic to Ecuador and Peru, respectively, are new species. Both are members of section Summikania. Dendroid hairs are reported on the leaves, stems, and capitulescences of M. wurdackii and compared to somewhat similar structures reported elsewhere in the genus only on the cypselae of two Brazilian species. C1 Baylor Univ, Dept Biol, Waco, TX 76798 USA. Smithsonian Inst, Dept Bot, US Natl Herbarium, Washington, DC 20560 USA. RP Holmes, WC (reprint author), Baylor Univ, Dept Biol, Waco, TX 76798 USA. NR 12 TC 4 Z9 4 U1 0 U2 1 PU AMER SOC PLANT TAXONOMISTS PI BRONX PA NEW YORK BOTANICAL GARDEN, BRONX, NY 10458-5126 USA SN 0363-6445 J9 SYST BOT JI Syst. Bot. PD OCT-DEC PY 2000 VL 25 IS 4 BP 571 EP 576 DI 10.2307/2666721 PG 6 WC Plant Sciences; Evolutionary Biology SC Plant Sciences; Evolutionary Biology GA 387VX UT WOS:000166143500001 ER PT J AU Ebinger, JE Seigler, DS Clarke, HD AF Ebinger, JE Seigler, DS Clarke, HD TI Taxonomic revision of South American species of the genus Acacia subgenus Acacia (Fabaceae : Mimosoideae) SO SYSTEMATIC BOTANY LA English DT Article ID LEGUMINOSAE; BIOLOGY; REGION; MEXICO AB Detailed descriptions, habitat preferences, geographic range, and representative specimens are given for the 13 native and two introduced taxa of Acacia subgenus Acacia (approximately the same as Acacia series Gummiferae) that are found in the South American flora. Some of these taxa are wide ranging. Acacia macracantha, A. tortuosa, and A. farnesiana are extremely common in northern South America, whereas A. caven and A. aroma occur throughout much of the southern half of the continent. The remaining species have restricted ranges, being found in relatively small areas. Principal components analysis (PCA) of vegetative and floral features shows that these species form discrete groups in plots of the first three principal components. From these data, most of the species were found to be relatively homogeneous, as indicated by the tight clusters formed in the PCA plots. In contrast, A. macracantha, a species ranging from Florida, south through the Caribbean, into South America, and in Mexico, is highly variable morphologically. The data suggest little gene flow between species. Hybrids are extremely uncommon. C1 Eastern Illinois Univ, Charleston, IL 61920 USA. Univ Illinois, Dept Plant Biol, Urbana, IL 61801 USA. Smithsonian Inst, Dept Bot, Washington, DC 20560 USA. RP Ebinger, JE (reprint author), Eastern Illinois Univ, Charleston, IL 61920 USA. NR 52 TC 21 Z9 24 U1 0 U2 3 PU AMER SOC PLANT TAXONOMISTS PI BRONX PA NEW YORK BOTANICAL GARDEN, BRONX, NY 10458-5126 USA SN 0363-6445 J9 SYST BOT JI Syst. Bot. PD OCT-DEC PY 2000 VL 25 IS 4 BP 588 EP 617 DI 10.2307/2666723 PG 30 WC Plant Sciences; Evolutionary Biology SC Plant Sciences; Evolutionary Biology GA 387VX UT WOS:000166143500003 ER PT J AU Evans, TM Faden, RB Simpson, MG Sytsma, KJ AF Evans, TM Faden, RB Simpson, MG Sytsma, KJ TI Phylogenetic relationships in the commelinaceae: I. A cladistic analysis of morphological data SO SYSTEMATIC BOTANY LA English DT Article ID RBCL SEQUENCE DATA; TAXA AB The plant family Commelinaceae displays a wide range of variation in vegetative, floral, and inflorescence morphology. This high degree of variation, particularly among characters operating under strong and similar selective pressures (i.e., flowers), has made the assessment of homology among morphological characters difficult, and has resulted in several discordant classification schemes for the family. Phylogenetic relationships among 40 of the 41 genera in the family were evaluated using cladistic analyses of morphological data. The resulting phylogeny shows some similarity to the most recent classification, but with some notable differences. Cartonema (subfamily Cartonematoideae) was placed basal to the rest of the family. Triceratella (subfamily Cartonematoideae), however, was placed among genera within tribe Tradescantieae of subfamily Commelinoideae. Likewise, the circumscriptions of tribes Commelineae and Tradescantieae were in disagreement with the most recent classification. The discordance between the phylogeny and the most recent classification is attributed to a high degree of convergence in various morphological characters, particularly those relating to the androecium and the inflorescence. Anatomical characters (i.e., stomatal structure), on the other hand, show promise for resolving phylogenetic relationships within the Commelinaceae, based upon their agreement with the most recent classification. C1 Univ Wisconsin, Dept Bot, Madison, WI 53706 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, NHB 166, Washington, DC 20560 USA. San Diego State Univ, Dept Biol, San Diego, CA 92182 USA. RP Evans, TM (reprint author), Hope Coll, Dept Biol, 35 E 12th St, Holland, MI 49423 USA. NR 66 TC 24 Z9 29 U1 0 U2 3 PU AMER SOC PLANT TAXONOMISTS PI BRONX PA NEW YORK BOTANICAL GARDEN, BRONX, NY 10458-5126 USA SN 0363-6445 J9 SYST BOT JI Syst. Bot. PD OCT-DEC PY 2000 VL 25 IS 4 BP 668 EP 691 DI 10.2307/2666727 PG 24 WC Plant Sciences; Evolutionary Biology SC Plant Sciences; Evolutionary Biology GA 387VX UT WOS:000166143500007 ER PT J AU Bridle, JR Jiggins, CD Tregenza, T AF Bridle, JR Jiggins, CD Tregenza, T TI Disruptive sexual selection - Reply SO TRENDS IN ECOLOGY & EVOLUTION LA English DT Letter ID SYMPATRIC SPECIATION C1 UCL, Galton Lab, Dept Biol, London NW1 2HE, England. Smithsonian Trop Res Inst, Balboa AA 2072, Panama. Univ Leeds, Sch Biol, Leeds LS2 9JT, W Yorkshire, England. RP Bridle, JR (reprint author), UCL, Galton Lab, Dept Biol, London NW1 2HE, England. EM bridlejr@cardiff.ac.uk; jigginsc@stri.si.edu; gentbt@leeds.ac.uk RI Jiggins, Chris/B-9960-2008 OI Jiggins, Chris/0000-0002-7809-062X NR 8 TC 1 Z9 1 U1 1 U2 3 PU ELSEVIER SCIENCE LONDON PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 0169-5347 J9 TRENDS ECOL EVOL JI Trends Ecol. Evol. PD OCT PY 2000 VL 15 IS 10 BP 420 EP 420 DI 10.1016/S0169-5347(00)01954-6 PG 1 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA 356KW UT WOS:000089443300017 ER PT J AU Plotkin, JB Potts, MD Yu, DW Bunyavejchewin, S Condit, R Foster, R Hubbell, S LaFrankie, J Manokaran, N Seng, LH Sukumar, R Nowak, MA Ashton, PS AF Plotkin, JB Potts, MD Yu, DW Bunyavejchewin, S Condit, R Foster, R Hubbell, S LaFrankie, J Manokaran, N Seng, LH Sukumar, R Nowak, MA Ashton, PS TI Predicting species diversity in tropical forests SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID AREA CURVES AB A fundamental question in ecology is how many species occur within a given area. Despite the complexity and diversity of different ecosystems. there exists a surprisingly simple, approximate answer: the number of species is proportional to the size of the area raised to some exponent. The exponent often turns out to be roughly 1/4. This power law can be derived from assumptions about the relative abundances of species or from notions of self-similarity. Here we analyze the largest existing data set of location-mapped species: over one million, individually identified trees from five tropical forests on three continents. Although the power law is a reasonable, zeroth-order approximation of our data, we find consistent deviations from it on all spatial scales. Furthermore, tropical forests are not self-similar at areas less than or equal to 50 hectares. We develop an extended model of the species-area relationship, which enables us to predict large-scale species diversity from small-scale data samples more accurately than any other available method. C1 Inst Adv Study, Princeton, NJ 08540 USA. Princeton Univ, Princeton, NJ 08540 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Harvard Univ, Dept Organismal & Evolutionary Biol, Cambridge, MA 02138 USA. Univ London Imperial Coll Sci Technol & Med, Ctr Populat Biol, Ascot SL5 7PY, Berks, England. Royal Forest Dept, Silvicultural Res Div, Bangkok 10900, Thailand. Smithsonian Trop Res Inst, Ctr Trop Forest Sci, Balboa, Panama. Field Museum Nat Hist, Dept Bot, Chicago, IL 60605 USA. Univ Georgia, Dept Bot, Athens, GA 30602 USA. Nanyang Technol Univ, Natl Inst Educ, Ctr Trop Forest Sci, Singapore 1025, Singapore. Forest Res Inst Malaysia, Kepong 52109, Malaysia. Sarawak Forestry Dept, SW-93750 Kuching, Sarawak, Malaysia. Indian Inst Sci, Ctr Ecol Sci, Bangalore 560012, Karnataka, India. RP Plotkin, JB (reprint author), Inst Adv Study, Olden Lane, Princeton, NJ 08540 USA. EM plotkin@ias.edu RI Yu, Douglas/D-2536-2009; Raman, Sukumar/C-9809-2013; Plotkin, Joshua/E-6947-2013; Nowak, Martin/A-6977-2008 NR 29 TC 112 Z9 118 U1 4 U2 31 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP 26 PY 2000 VL 97 IS 20 BP 10850 EP 10854 DI 10.1073/pnas.97.20.10850 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 358PH UT WOS:000089566100035 PM 11005859 ER PT J AU Trombka, JI Squyres, SW Bruckner, J Boynton, WV Reedy, RC McCoy, TJ Gorenstein, P Evans, LG Arnold, JR Starr, RD Nittler, LR Murphy, ME Mikheeva, I McNutt, RL McClanahan, TP McCartney, E Goldsten, JO Gold, RE Floyd, SR Clark, PE Burbine, TH Bhangoo, JS Bailey, SH Petaev, M AF Trombka, JI Squyres, SW Bruckner, J Boynton, WV Reedy, RC McCoy, TJ Gorenstein, P Evans, LG Arnold, JR Starr, RD Nittler, LR Murphy, ME Mikheeva, I McNutt, RL McClanahan, TP McCartney, E Goldsten, JO Gold, RE Floyd, SR Clark, PE Burbine, TH Bhangoo, JS Bailey, SH Petaev, M TI The elemental composition of asteroid 433 Eros: Results of the NEAR-Shoemaker x-ray spectrometer SO SCIENCE LA English DT Article ID RENDEZVOUS MISSION; INFRARED SPECTROMETER; MULTISPECTRAL IMAGER; TEMPERATURE; RADIATION; SPECTRUM; PLASMA AB We report major element composition ratios for regions of the asteroid 433 Eros imaged during two solar flares and quiet sun conditions during the period of May to July 2000, Low aluminum abundances for all regions argue against global differentiation of Eros. Magnesium/silicon, aluminum/silicon, calcium/silicon, and iron/silicon ratios are best interpreted as a relatively primitive, chondritic composition. Marked depletions in sulfur and possible aluminum and calcium depletions, relative to ordinary chondrites, may represent signatures of Limited partial melting or impact volatilization. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Cornell Univ, Ithaca, NY 14853 USA. Max Planck Inst Chem, D-55020 Mainz, Germany. Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Mineral Sci, Washington, DC 20560 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. Comp Sci Corp, Syst Sci Div, Laurel, MD 20707 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. RP Trombka, JI (reprint author), NASA, Goddard Space Flight Ctr, Code 691, Greenbelt, MD 20771 USA. RI McNutt, Ralph/E-8006-2010; OI McNutt, Ralph/0000-0002-4722-9166; Reedy, Robert/0000-0002-2189-1303 NR 30 TC 89 Z9 91 U1 0 U2 3 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD SEP 22 PY 2000 VL 289 IS 5487 BP 2101 EP 2105 DI 10.1126/science.289.5487.2101 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 356EG UT WOS:000089430900037 ER PT J AU Patel, SK Joy, M Carlstrom, JE Holder, GP Reese, ED Gomez, PL Hughes, JP Grego, L Holzapfel, WL AF Patel, SK Joy, M Carlstrom, JE Holder, GP Reese, ED Gomez, PL Hughes, JP Grego, L Holzapfel, WL TI The distance and mass of the galaxy cluster Abell 1995 derived from Sunyaev-Zeldovich effect and X-ray measurements SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; dark matter; distance scale; galaxies : clusters : individual (Abell 1995); X-rays : general ID RELATIVISTIC CORRECTIONS; VELOCITY DISPERSIONS; TEMPERATURE PROFILES; INTRACLUSTER MEDIUM; HUBBLE CONSTANT; SKY SURVEY; ABUNDANCES; H-0 AB We present multiwavelength observations of the Abell 1995 galaxy cluster. From an analysis of X-ray spectroscopy and imaging data, we derive the electron temperature, cluster core radius, and central electron number density. Using optical spectroscopy of 15 cluster members, we derive an accurate cluster redshift and velocity dispersion. Finally, the interferometric imaging of the Sunyaev-Zeldovich effect toward Abell 1995 at 28.5 GHz provides a measure of the integrated pressure through the cluster. The X-ray and Sunyaev-Zeldovich effect observations are combined to determine the angular diameter distance to the cluster of D-A = 1294(-283)(-458)(+294)(+438) Mpc (statistical followed by systematic uncertainty), implying a Hubble constant of H-0 = 52.2 (+11.4)(+18.5)(-11.9)(-17.7) km s(-1) Mpc(-1) for Ohm(M) = 0.3 and Ohm(Lambda) = 0.7. We find a best-fit H-0 of 46 km s(-1) Mpc(-1) for the Ohm(M) - 1 and Ohm(Lambda) = 0 cosmology, and 48 km s(-1) Mpc(-1) for = 0.3 and Ohm(Lambda) = 0.0. The X-ray data are also used to derive a total cluster mass of M-tot(HSE)(r(500)) = 5.18(-0.48)(+0.62) x 10(14) h(-1) M.; the optical velocity dispersion yields an independent and consistent estimate of M-tot(virial)(r(500)) = 6.35(-1.19)(+1.51) X 10(14) h(-1) M.. Both of the total mass estimates are evaluated at a fiducial radius, r(500) = 830 h(-1) kpc, where the overdensity is 500 times the critical density. The total cluster mass is then combined with gas mass measurements to determine a cluster gas mass fraction of f(g) = 0.056(-0.013)(+0.010)h(-3/2). In combination with recent baryon density constraints, the measured gas mass fraction yields an upper limit on the mass density parameter of Ohm(M) h(1/2) less than or equal to 0.34(-0.05)(+0.06). C1 NASA, George C Marshall Space Flight Ctr, Dept Space Sci, Huntsville, AL 35812 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08854 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Patel, SK (reprint author), Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. RI Holzapfel, William/I-4836-2015 NR 60 TC 30 Z9 31 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 20 PY 2000 VL 541 IS 1 BP 37 EP 48 DI 10.1086/309411 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360YE UT WOS:000089694300004 ER PT J AU van Dokkum, PG Franx, M Fabricant, D Illingworth, GD Kelson, DD AF van Dokkum, PG Franx, M Fabricant, D Illingworth, GD Kelson, DD TI Hubble Space Telescope photometry and Keck spectroscopy of the rich cluster MS 1054-03: Morphologies, Butcher-Oemler effect, and the color-magnitude relation at z=0.83 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : clusters : individual (MS 1054-03); galaxies : elliptical and lenticular, cD galaxies : evolution; galaxies : structure ID EARLY-TYPE GALAXIES; HIGH-REDSHIFT CLUSTERS; DISTANT CLUSTERS; FUNDAMENTAL PLANE; S0 GALAXIES; ELLIPTIC GALAXIES; EVOLUTION; CLUSTER-0023+0423; CLUSTER-1604+4304; POPULATIONS AB We present a study of 81 I-band selected, spectroscopically confirmed members of the X-ray cluster MS 1054-03 at z = 0.83. Redshifts and spectral types were determined from Keck spectroscopy. Morphologies and accurate colors were determined from a large mosaic of HST WFPC2 images in R-F606W and I-F814W, corresponding to U and B in the rest frame. Early-type galaxies constitute only 44% of this galaxy population. This fraction is much lower than in comparable rich clusters at low redshift. Thirty-nine percent are spiral galaxies, and 17% are mergers. The early-type galaxies follow a tight and well-defined color-magnitude relation, with the exception of a few outliers. The observed scatter is 0.029 +/- 0.005 mag in rest frame U-B. Most of the mergers lie close to the CM relation defined by the early-type galaxies. They are bluer by only 0.07 +/- 0.02 mag, and the scatter in their colors is 0.07 +/- 0.04 mag. Spiral galaxies in MS 1054-03 exhibit a large range in their colors. The bluest spiral galaxies are similar to 0.7 mag bluer than the early-type galaxies, but the majority is within +/-0.2 mag of the early-type galaxy sequence. The red colors of the mergers and the majority of the spiral galaxies are reflected in the fairly low Butcher-Oemler blue fraction of MS 1054-03: f(B) = 0.22 +/- 0.05, similar to intermediate redshift clusters and much lower than previously reported values for clusters at z similar to 0.8. The slope and scatter of the CM relation of early-type galaxies are roughly constant with redshift, confirming previous studies that were based on ground-based color measurements and very limited membership information. However, the scatter in the combined sample of early-type galaxies and mergers (i.e., the sample of future early-type galaxies) is twice as high as the scatter of the early-type galaxies alone. This is a direct demonstration of the "progenitor bias": high-redshift early-type galaxies seem to form a homogeneous, old population because the progenitors of the youngest present-day early-type galaxies are not included in the sample. C1 Leiden Observ, NL-2300 RA Leiden, Netherlands. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02318 USA. Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Santa Cruz, CA 95064 USA. Carnegie Inst Washington, DTM, Washington, DC 20015 USA. RP van Dokkum, PG (reprint author), CALTECH, MS 105-24, Pasadena, CA 91125 USA. NR 70 TC 234 Z9 234 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 20 PY 2000 VL 541 IS 1 BP 95 EP 111 DI 10.1086/309402 PN 1 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360YE UT WOS:000089694300010 ER PT J AU Ozel, F Psaltis, D Narayan, R AF Ozel, F Psaltis, D Narayan, R TI Hybrid thermal-nonthermal synchrotron emission from hot accretion flows SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; Galaxy : center; radiation mechanisms : nonthermal; radiation mechanisms : thermal ID ADVECTION-DOMINATED ACCRETION; SAGITTARIUS-A-ASTERISK; BLACK-HOLE; GALACTIC-CENTER; MODEL; SPECTRUM; ELECTRONS; DISTRIBUTIONS; OUTFLOWS; PLASMAS AB We investigate the effect of a hybrid electron population, consisting of both thermal and nonthermal particles, on the synchrotron spectrum, image size, and image shape of a hot accretion flow onto a supermassive black hole. We find two universal features in the emitted synchrotron spectrum: (1) a prominent shoulder at low (less than or similar to 10(11) Hz) frequencies that is weakly dependent on the shape of the electron energy distribution, and (2) an extended tail of emission at high (greater than or similar to 10(13) Hz) frequencies whose spectral slope depends on the slope of the power-law energy distribution of the electrons. In the low-frequency shoulder, the luminosity can be up to 2 orders of magnitude greater than with a purely thermal plasma even if only a small fraction (<1%) of the steady state electron energy is in the nonthermal electrons. We apply the hybrid model to the Galactic center source, Sgr A*. The observed radio and IR spectra imply that at most 1% of the steady state electron energy is present in a power-law tail in this source. This corresponds to no more than 10% of the electron energy injected into the nonthermal electrons and hence 90% into the thermal electrons. We show that such a hybrid distribution can be sustained in the flow because thermalization via Coulomb collisions and synchrotron self-absorption are both inefficient. The presence of nonthermal electrons enlarges the size of the radio image at low frequencies and alters the frequency dependence of the brightness temperature. A purely thermal electron distributions produces a sharp-edged image, while a hybrid distribution causes strong limb brightening. These effects can be seen up to frequencies similar to 10(11) Hz and are accessible to radio interferometers. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Ozel, F (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 45 TC 64 Z9 63 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 20 PY 2000 VL 541 IS 1 BP 234 EP 249 DI 10.1086/309396 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360YE UT WOS:000089694300023 ER PT J AU Kalogera, V AF Kalogera, V TI Spin-orbit misalignment in close binaries with two compact objects SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; gravitation; relativity; supernovae : general ID BLACK-HOLE FORMATION; NEUTRON-STARS; GRAVITATIONAL-RADIATION; KICK VELOCITY; WAVE EMISSION; MASS-LOSS; EVOLUTION; PULSAR; SYSTEMS; EXPLOSION AB Spin-orbit misalignment in coalescing compact binaries affects their gravitational radiation waveforms. When the misalignment angles are large (greater than or similar to 30 degrees), the detection efficiency of the coalescence events can decrease significantly if the misalignment effects are not modeled. In this paper, we consider the formation of close compact binaries and calculate the expected misalignment angles after the second core collapse event. Depending on the progenitor parameters and the assumptions made about supernova kicks, we find that 30%-80% of binaries containing a black hole and a neutron star that coalesce within 10(10) yr have misalignment angles larger than 30 degrees, and a significant fraction of them could remain undetected. The calculations allow us to place strong constraints on the progenitors of such binaries and the kick magnitudes required for their formation. We also discuss the formation of close binaries with two black holes and the effect of nonisotropic kicks. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Kalogera, V (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 39 TC 50 Z9 50 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD SEP 20 PY 2000 VL 541 IS 1 BP 319 EP 328 DI 10.1086/309400 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360YE UT WOS:000089694300032 ER PT J AU Perna, R Hernquist, L Narayan, R AF Perna, R Hernquist, L Narayan, R TI Emission spectra of fallback disks around young neutron stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; stars : neutron; X-rays : stars ID ADVECTION-DOMINATED ACCRETION; SPACE-TELESCOPE OBSERVATIONS; X-RAY PULSARS; MAGNETIC-FIELD; RX J0720.4-3125; BLACK-HOLES; SUPERNOVA AB The nature of the energy source powering anomalous X-ray pulsars (AXPs) is uncertain. Proposed scenarios involve either an ultramagnetized neutron star or accretion onto a neutron star. We consider the accretion model proposed recently by Chatterjee, Hernquist, & Narayan, in which a disk is fed by fallback material following a supernova. We compute the optical, infrared, and submillimeter emission expected from such a disk, including both viscous dissipation and reradiation of X-ray flux impinging on the disk from the pulsar. We find that it is possible with current instruments to put serious constraints on this and on other accretion models of AXPs. Fallback disks could also be found around isolated radio pulsars, and we compute the corresponding spectra. We show that the excess emission in the R and I bands observed for the pulsar PSR 0656+14 is broadly consistent with emission from a disk. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Perna, R (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI Narayan, Ramesh/0000-0002-1919-2730 NR 51 TC 105 Z9 106 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 20 PY 2000 VL 541 IS 1 BP 344 EP 350 DI 10.1086/309404 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360YE UT WOS:000089694300035 ER PT J AU Audard, M Gudel, M Drake, JJ Kashyap, VL AF Audard, M Gudel, M Drake, JJ Kashyap, VL TI Extreme-ultraviolet flare activity in late-type stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : activity; stars : coronae; stars : flare; stars : late-type; stars : rotation; X-rays : stars ID MAIN-SEQUENCE STARS; X-RAY-EMISSION; RAPIDLY ROTATING STARS; ALL-SKY SURVEY; CORONAL ACTIVITY; MICROFLARING ACTIVITY; MICROWAVE EMISSION; MAGNETIC ACTIVITY; STELLAR ROTATION; AU-MICROSCOPII AB Extreme Ultraviolet Explorer Deep Survey observations of cool stars (spectral type F to M) have been used to investigate the distribution of coronal flare rates in energy and its relation to activity indicators and rotation parameters. Cumulative and differential flare rate distributions were constructed and fitted with different methods. Power laws are found to approximately describe the distributions. A trend toward flatter distributions for later type stars is suggested in our sample. Assuming that the power laws continue below the detection limit, we have estimated that the superposition of Bares with radiated energies of about 10(29)-10(31) ergs could explain the observed radiative power loss of these coronae, while the detected Bares are contributing only approximate to 10%. Although the power-law index is not correlated with rotation parameters (rotation period, projected rotational velocity, Rossby number) and only marginally with the X-ray luminosity, the flare occurrence rate is correlated with all of them. The occurrence rate of flares with energies larger than 10(32) ergs is found to be proportional to the average total stellar X-ray luminosity. Thus, energetic flares occur more often in X-ray bright stars than in X-ray faint stars. The normalized occurrence rate of flares with energies larger than 1032 ergs increases with increasing L-X/L-bol and stays constant for saturated stars. A similar saturation is found below a critical Rossby number. The findings are discussed in terms of simple statistical hare models in an attempt to explain the previously observed trend for higher average coronal temperatures in more active stars. It is concluded that flares can contribute a significant amount of energy to coronal heating in active stars. C1 Paul Scherrer Inst, Astrophys Lab, CH-5232 Villigen, Switzerland. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Swiss Fed Inst Technol, Inst Astron, CH-8092 Zurich, Switzerland. EM audard@astro.phys.ethz.ch; guedel@astro.phys.ethz.ch; jdrake@cfa.harvard.edu; vkashyap@cfa.harvard.edu RI Guedel, Manuel/C-8486-2015 OI Guedel, Manuel/0000-0001-9818-0588 NR 82 TC 122 Z9 122 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD SEP 20 PY 2000 VL 541 IS 1 BP 396 EP 409 DI 10.1086/309426 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360YE UT WOS:000089694300040 ER PT J AU Silver, E Schnopper, H Bandler, S Brickhouse, N Murray, S Barbera, M Takacs, E Gillaspy, JD Porto, JV Kink, I Laming, JM Madden, N Landis, D Beeman, J Haller, EE AF Silver, E Schnopper, H Bandler, S Brickhouse, N Murray, S Barbera, M Takacs, E Gillaspy, JD Porto, JV Kink, I Laming, JM Madden, N Landis, D Beeman, J Haller, EE TI Laboratory astrophysics survey of key X-ray diagnostic lines using a microcalorimeter on an electron beam ion trap SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic data; atomic processes; line : identification; methods : laboratory; plasmas; X-rays : general ID POLARIZATION; EMISSION AB Cosmic plasma conditions created in an electron beam ion trap (EBIT) make it possible to simulate the dependencies of key diagnostic X-ray lines on density, temperature, and excitation conditions that exist in astrophysical sources. We used a microcalorimeter for such laboratory astrophysics studies because it has a resolving power approximate to 1000, quantum efficiency approaching 100%, and a bandwidth that spans the X-ray energies from 0.2 keV to 10 keV. Our microcalorimeter, coupled with an X-ray optic to increase the effective solid angle, provides a significant new capability for laboratory astrophysics measurements. Broadband spectra obtained from the National Institute of Standards and Technology EBIT with an energy resolution approaching that of a Bragg crystal spectrometer are presented for nitrogen, oxygen, neon, argon, and krypton in various stages of ionization. We have compared the measured line intensities to theoretical predictions for an EBIT plasma. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Osserv Astron GS Vaiana, I-90134 Palermo, Italy. MIT, Cambridge, MA 02139 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. USN, Res Lab, Washington, DC 20375 USA. RP Silver, E (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Bandler, Simon/A-6258-2010; OI Bandler, Simon/0000-0002-5112-8106; Brickhouse, Nancy/0000-0002-8704-4473; Barbera, Marco/0000-0002-3188-7420 NR 18 TC 36 Z9 37 U1 1 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 20 PY 2000 VL 541 IS 1 BP 495 EP 500 DI 10.1086/309420 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360YE UT WOS:000089694300049 ER PT J AU Bolatto, AD Jackson, JM Kraemer, KE Zhang, XL AF Bolatto, AD Jackson, JM Kraemer, KE Zhang, XL TI First detection of submillimeter [C I] emission in the small magellanic cloud SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : irregular; galaxies : ISM; ISM : clouds; ISM : lines and bands; Magellanic Clouds; submillimeter ID LONG-WAVELENGTH SPECTROMETER; SEST KEY PROGRAM; ABUNDANCE; GALAXIES; REGIONS; CARBON; MODEL; RATIO AB We report the first detection of [C I] (P-3(1) --> P-3(0)) emission at 609 mu m in a region of the Small Magellanic Cloud (N27). Environments poor in heavy elements and dust such as the SMC are thought to be dominated by photodissociation regions (PDRs), This is the lowest metallicity source where submillimeter neutral carbon emission has been detected. Studying the I-[CI]\I-CO ratio in several sources spanning more than an order of magnitude in metallicity Z, we find that the I-[CI]\I-CO ratio increases for decreasing Z. The existence of such a trend points to a photodissociation origin for most of the neutral carbon in molecular clouds, in agreement with standard PDR models. We also report Infrared Space Observatory far-infrared (FIR) spectroscopic observations of N27 and use them to derive its physical properties. Comparison between the density and radiation field revealed by FIR diagnostics (n similar to 300-1000 cm(-3), chi(uv) similar to 30 chi(0)-100 chi(0)) and those derived from millimeter and submillimeter data (n similar to 10(5) cm(-3), chi(uv) greater than or similar to 30 chi(0)) suggests that the FIR lines originate in more diffuse gas and are perhaps dominated by the interclump medium. Regardless of the cause, analysis of the FIR and millimeter-submillimeter data produces a discrepancy of 2 orders of magnitude for the density of this source. C1 Boston Univ, Dept Astron, Inst Astrophys Res, Boston, MA 02215 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. RP Bolatto, AD (reprint author), Boston Univ, Dept Astron, Inst Astrophys Res, 725 Commonwealth Ave, Boston, MA 02215 USA. NR 25 TC 7 Z9 7 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 20 PY 2000 VL 541 IS 1 BP L17 EP L20 DI 10.1086/312893 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360YH UT WOS:000089694600005 ER PT J AU Greene, CH Dickinson, AS Sadeghpour, HR AF Greene, CH Dickinson, AS Sadeghpour, HR TI Creation of polar and nonpolar ultra-long-range Rydberg molecules SO PHYSICAL REVIEW LETTERS LA English DT Article ID ATOMS; GAS; COLLISIONS; SYSTEMS; STATES; SPECTRA; CURVES AB We predict the existence of a ubiquitous class of long-range molecular Rydberg states, whose Born-Oppenheimer potential curves are oscillatory in nature. These oscillations reflect the nodal structure of the atomic Rydberg state wave functions. The temperature and density of atoms in a Bose-Einstein condensate an particularly favorable for the laser excitation of ultra-long-range vibrational bound states localized at internuclear distances in the range 10(3)-10(5) a.u. A surprising trilobitelike class of polar homonuclear diatomics should exhibit electric dipole moments in the kilodebye range. C1 Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Univ Colorado, JILA, Boulder, CO 80309 USA. Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Univ Newcastle Upon Tyne, Dept Phys, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England. RP Greene, CH (reprint author), Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RI Greene, Chris/C-3821-2011 OI Greene, Chris/0000-0002-2096-6385 NR 25 TC 208 Z9 208 U1 2 U2 24 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 18 PY 2000 VL 85 IS 12 BP 2458 EP 2461 DI 10.1103/PhysRevLett.85.2458 PG 4 WC Physics, Multidisciplinary SC Physics GA 355NV UT WOS:000089392500012 ER PT J AU Guan, Y McKeegan, KD MacPherson, GJ AF Guan, Y McKeegan, KD MacPherson, GJ TI Oxygen isotopes in calcium-aluminum-rich inclusions from enstatite chondrites: new evidence for a single CAI source in the solar nebula SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE oxygen; isotopes; enstatite chondrites; calcium-aluminum inclusions; solar system ID CARBONACEOUS CHONDRITES; METEORITES; ALLENDE; COMPONENT; ANOMALIES AB Calcium-aluminum-rich inclusions (CAIs) from enstatite chondrites have large O-16 excesses, similar to CAIs in carbonaceous and ordinary chondrites, and are also similar in morphology, mineralogy and Al-Mg isotopic systematics. These similarities provide new evidence that most CAIs might have formed in a single, restricted nebular locale and were then distributed unevenly throughout the various chondrite accretion regions. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Mineral Sci, Washington, DC 20560 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. RP MacPherson, GJ (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Mineral Sci, Washington, DC 20560 USA. RI McKeegan, Kevin/A-4107-2008; UCLA, SIMS/A-1459-2011 OI McKeegan, Kevin/0000-0002-1827-729X; NR 27 TC 40 Z9 45 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD SEP 15 PY 2000 VL 181 IS 3 BP 271 EP 277 DI 10.1016/S0012-821X(00)00218-1 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 355PN UT WOS:000089394200001 ER PT J AU Kalfatovic, MR AF Kalfatovic, MR TI Wyndham Lewis: Painter and writer. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst Lib, Washington, DC 20560 USA. RP Kalfatovic, MR (reprint author), Smithsonian Inst Lib, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD SEP 15 PY 2000 VL 125 IS 15 BP 66 EP 66 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA 353QR UT WOS:000089287400031 ER PT J AU Evans, NR AF Evans, NR TI Astronomy - Don't we already know everything about Polaris? SO SCIENCE LA English DT Editorial Material ID CEPHEID C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Evans, NR (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD SEP 15 PY 2000 VL 289 IS 5486 BP 1888 EP 1889 DI 10.1126/science.289.5486.1888 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 354XD UT WOS:000089355800030 PM 17839931 ER PT J AU Jha, S Torres, G Stefanik, RP Latham, DW Mazeh, T AF Jha, S Torres, G Stefanik, RP Latham, DW Mazeh, T TI Studies of multiple stellar systems - III. Modulation of orbital elements in the triple-lined system HD 109648 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE celestial mechanics, stellar dynamics; binaries : spectroscopic; stars : individual : HD 109648 ID SPECTROSCOPIC BINARIES; OPEN CLUSTERS; 3RD STAR; COMPONENTS; TODCOR AB The triple-lined spectroscopic triple system HD 109648 has one of the shortest periods known for the outer orbit in a late-type triple, 120.5 d, and the ratio between the periods of the outer and the inner orbits is small, 22:1. With such extreme values, this system should show orbital element variations over a time-scale of about a decade. We have monitored the radial velocities of HD 109648 with the CfA Digital Speedometers for 8 yr, and have found evidence for modulation of some orbital elements. While we see no definite evidence for modulation of the inner binary eccentricity, we clearly observe variations in the inner and the outer longitudes of periastron, and in the radial velocity amplitudes of the three components. The observational results, combined with numerical simulations, allow us to put constraints on the orientation of the orbits. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. RP Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM sjha@cfa.harvard.edu; gtorres@cfa.harvard.edu; rstefanik@cfa.harvard.edu; dlatham@cfa.harvard.edu; mazeh@wise.tau.ac.il NR 33 TC 17 Z9 17 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0035-8711 EI 1365-2966 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD SEP 11 PY 2000 VL 317 IS 2 BP 375 EP 384 DI 10.1046/j.1365-8711.2000.03592.x PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 355TF UT WOS:000089401400016 ER PT J AU Lobel, A Bagnulo, S Doyle, JG Power, C AF Lobel, A Bagnulo, S Doyle, JG Power, C TI Modelling near-IR spectra and mid-IR dust emission of Mira variables at different phases SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE stars : AGB and post-AGB; circumstellar matter; stars : individual : o Cet; stars : individual : U Ori; stars : variables : other; infrared : stars ID LATE-TYPE STARS; M-GIANTS; O-CETI; INFRARED OBSERVATIONS; EVOLVED STARS; MASS-LOSS; ATMOSPHERES; TIO; SHELLS; PHOTOMETRY AB We model the spectral changes of late oxygen-rich Miras observed in different pulsation phases. From a combination of variable near-IR spectra and UKIRT spectro-photometry of the 9.7-mu m silicate dust emission feature in different phases we study the influence of the changing atmospheric circumstances on the conditions in the circumstellar dust shell. From a detailed modelling of TiO and VO bands in the near-IR spectra, we determine changes of the effective temperature and the effective atmospheric acceleration of the central star. The corresponding model spectral energy distribution is redistributed through the dust shell by means of radiative transfer calculations in order to perform a detailed modelling of shape changes observed in the silicate feature. We show that the latter are mainly caused by changes in the flux distribution of the incident radiation field with stellar pulsation, whereas intensity changes of the dust emission result from stellar luminosity changes as they are enshrouded by very optically thin dust shells. In the case of the Mira o Cet we compute that the effective temperature increases from T-eff = 2400 K in the minimum phase to 3000 K (+/- 100 K) around the maximum phase. The amplified momentum transfer around maximum light enhances the acceleration of the dust outflow near the dust condensation radius of similar to 6 R-*. This produces variations of the terminal dust outflow velocity with phase (Delta v(infinity) similar or equal to 5 km s(-1)) at larger distance from the star. The corresponding small changes in flux mean opacity and gas mass-loss rates (from 2.8 to 3.2 x 10(-7) M. yr(-1)) are sufficient to model the shape changes observed in the dust emission feature. A comparison with the modelling results for another long period Mira, U Ori, is also provided. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Vienna, Inst Astron, A-1180 Vienna, Austria. Armagh Observ, Armagh BT61 9DG, North Ireland. RP Lobel, A (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Power, Chris/C-2480-2013 OI Power, Chris/0000-0002-4003-0904 NR 66 TC 15 Z9 15 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD SEP 11 PY 2000 VL 317 IS 2 BP 391 EP 405 DI 10.1046/j.1365-8711.2000.03563.x PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 355TF UT WOS:000089401400018 ER PT J AU Vaisanen, P Tollestrup, EV Willner, SP Cohen, M AF Vaisanen, P Tollestrup, EV Willner, SP Cohen, M TI Wide-field J- and K-band galaxy counts in the European large-area Infrared Space Observatory survey fields SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; galaxies : evolution; galaxies : photometry infrared : galaxies; surveys ID PALOMAR SKY SURVEY; LUMINOSITY FUNCTIONS; FAINT GALAXIES; REDSHIFT SURVEY; DISTRIBUTIONS; ENVIRONMENTS; PHOTOMETRY; EVOLUTION; CATALOG; COLORS AB New near-infrared galaxy counts in the J and K bands are presented over a total area of 0.70 and 0.97 deg(2), respectively. The limiting magnitudes of the deepest regions are 19.5 in J and 18.0 in K. At J > 16 and K > 15, our J- and K-band number counts agree well with existing surveys, provided that all data are corrected to a common magnitude scale. There are real differences from held to held, and the European Large-Area ISO Survey (ELAIS) N1 and N2 fields show an overdensity of J < 16, K < 15 galaxies. The slopes of log N(m)/dm are similar to 0.40-0.45 at 15 < K < 18 and 16 < J < 19.5. Our counts favor galaxy models with a high normalization of the local luminosity function and without strong evolution. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Helsinki Observ, Helsinki 00014, Finland. Univ Calif Berkeley, Radio Astron Lab, Berkeley, CA 94720 USA. Vanguard Res Inc, Scotts Valley, CA 95066 USA. RP Vaisanen, P (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St,MS 66, Cambridge, MA 02138 USA. NR 46 TC 33 Z9 33 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2000 VL 540 IS 2 BP 593 EP 604 DI 10.1086/309389 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360DH UT WOS:000089650800001 ER PT J AU Ciardi, B Loeb, A AF Ciardi, B Loeb, A TI Expected number and flux distribution of gamma-ray burst afterglows with high redshifts SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : ISM; gamma rays : bursts; intergalactic medium ID 28 FEBRUARY 1997; LIGHT CURVES; OPTICAL COUNTERPART; RADIATIVE-TRANSFER; CLUMPY UNIVERSE; MAGNETIC-FIELDS; FIRST QUASARS; GALAXIES; REIONIZATION; EMISSION AB If gamma-ray bursts (GRBs) occur at high redshifts, then their bright afterglow emission can be used to probe the ionization and metal enrichment histories of the intervening intergalactic medium during the epoch of reionization. In contrast to other sources, such as galaxies or quasars, which fade rapidly with increasing redshift, the observed infrared flux from a GRB afterglow at a fixed observed age is only a weak function of its redshift. This results from a combination of the spectral slope of GRB afterglows and the time stretching of their evolution in the observer's frame. Assuming that the GRB rate is proportional to the star formation rate and that the characteristic energy output of GRBs is similar to 10(52) ergs, we predict that there are always similar to 15 GRBs from redshifts z greater than or similar to 5 across the sky that are brighter than similar to 100 nJy at an observed wavelength of similar to 2 mu m. The infrared spectrum of these sources could be taken with the future Next Generation Space Telescope as a follow-up to early X-ray localization with the Swift satellite. C1 Univ Florence, Dipartimento Astron, Florence, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Ciardi, B (reprint author), Univ Florence, Dipartimento Astron, Largo E Fermi 5, Florence, Italy. RI Ciardi, Benedetta/N-7625-2015 NR 74 TC 144 Z9 146 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2000 VL 540 IS 2 BP 687 EP 696 DI 10.1086/309384 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360DH UT WOS:000089650800007 ER PT J AU Medvedev, MV AF Medvedev, MV TI Theory of "jitter" radiation from small-scale random magnetic fields and prompt emission from gamma-ray burst shocks SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; magnetic fields; radiation mechanisms : nonthermal ID SPECTRAL CHARACTERISTICS; AFTERGLOW; MODEL; POLARIZATION; SYNCHROTRON; EVOLUTION; BATSE; GRB-990510; FIREBALL; LINES AB We demonstrate that the radiation emitted by ultrarelativistic electrons in highly nonuniform, small-scale magnetic fields is different from synchrotron radiation if the electron's transverse deflections in these fields are much smaller than the beaming angle. A quantitative analytical theory of this radiation, which we refer to as jitter radiation, is developed. It is shown that the emergent spectrum is determined by statistical properties of the magnetic field. The jitter radiation theory is then applied to internal shocks of gamma-ray bursts (GRBs). The model of a magnetic field in GRBs proposed by Medvedev & Loeb in 1999 is used. The spectral power distribution of radiation produced by the power-law-distribute electrons with a low-energy cutoff is well described by a sharply broken power law: P(omega) proportional to omega(1) for omega less than or similar to omega(jm) and P(omega) proportional to omega(-(p-1)/2) for omega greater than or similar to omega(jm), where p is the electron power-law index and omega(jm) is the jitter break frequency, which is independent of the field strength but depends on the electron density in the ejecta, omega(jm) proportional to n(1/2), as well as on the shock energetics and kinematics. The total emitted power of jitter radiation is; however, equal to that of synchrotron radiation. Since large-scale fields may also be present in the ejecta, we construct a two-component, jitter + synchrotron spectral model of the prompt gamma-ray emission. Quite surprisingly, this model seems to be readily capable of explaining several properties of time-resolved spectra of some GRBs, such as (1) the violation of the constraint on the low-energy spectral index called the synchrotron "line of death," (2) the sharp spectral break at the peak frequency, inconsistent with the broad synchrotron bump, (3) the evidence for two spectral subcomponents, and (4) possible existence of emission features called "GRB lines." We believe these facts strongly support both the existence of small-scale magnetic fields and the proposed radiation mechanism from GRB shocks. As an example, we use the composite model to analyze GRB 910503, which has two spectral peaks. At last, we emphasize that accurate GRB spectra may allow precise determination of fireball properties as early as several minutes after the explosion. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RRC Kurchatov Inst, Inst Nucl Fus, Moscow 123182, Russia. RP Medvedev, MV (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 36 TC 185 Z9 186 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2000 VL 540 IS 2 BP 704 EP 714 DI 10.1086/309374 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360DH UT WOS:000089650800009 ER PT J AU Wada, K Spaans, M Kim, S AF Wada, K Spaans, M Kim, S TI Formation of cavities, filaments, and clumps by the nonlinear development of thermal and gravitational instabilities in the interstellar medium under stellar feedback SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (Large Magellanic Cloud); galaxies : structure; ISM : kinematics and dynamics; ISM : structure; methods : numerical ID LARGE-MAGELLANIC-CLOUD; PHOTON-DOMINATED REGIONS; N-BODY SIMULATIONS; STAR-FORMATION; TURBULENT MODEL; NUMERICAL-SIMULATION; SUPERNOVA EXPLOSIONS; HOLMBERG-II; GALAXIES; HOLES AB Based on our high-resolution two-dimensional hydrodynamical simulations, we propose that large cavities may be formed by the nonlinear development of the combined thermal and gravitational instabilities, without need for stellar energy injection in a galaxy modeling the Large Magellanic Cloud (LMC). Our numerical model of star formation allows us to follow the evolution of the blast waves due to supernovae in the inhomogenous, multiphase, and turbulent-like media self-consistently. Formation of kiloparsec-scale inhomogeneity, such as cavities as seen in the observed H I map of the LMC, is suppressed by frequent supernovae (the average supernova rate for the whole disk is similar to 0.001 yr(-1)). However, the supernova explosions are necessary for the hot component (T-g > 10(6)-10(7) K). Position-velocity maps show that kiloparsec-scale shells/arcs formed through nonlinear evolution in a model without stellar energy feedback have kinematics similar to explosive phenomena, such as supernovae. We also find that dense clumps and filamentary structure are formed as a natural consequence of the nonlinear evolution of the multiphase interstellar medium (ISM). Although the ISM on a small scale looks turbulent-like and transient, the global structure of the ISM is quasi-stable. In the quasi-stable phase, the volume filling factor of the hot, warm, and cold components are similar to 0.2, similar to 0.6, and similar to 0.2, respectively. We compare observations of H I and molecular gas of the LMC with the numerically obtained H I and CO brightness temperature distributions. The morphology and statistical properties of the numerical H I and CO maps are discussed. We find that the cloud mass spectra of our models represent a power-law shape, but their slopes change between models with and without the stellar energy injection. We also find that the slope depends on the threshold brightness temperature of CO. C1 Natl Astron Observ, Mitaka, Tokyo 1818588, Japan. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Illinois, Dept Astron, Urbana, IL 61801 USA. RP Wada, K (reprint author), Natl Astron Observ, Mitaka, Tokyo 1818588, Japan. NR 54 TC 85 Z9 86 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2000 VL 540 IS 2 BP 797 EP 807 DI 10.1086/309347 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360DH UT WOS:000089650800016 ER PT J AU Green, PJ Ali, B Napiwotzki, R AF Green, PJ Ali, B Napiwotzki, R TI Cool companions to hot white dwarfs SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; stars : atmospheres; stars : evolution; white dwarfs ID EXTREME-ULTRAVIOLET EXPLORER; LOW-MASS STARS; LOCAL INTERSTELLAR-MEDIUM; ALL-SKY SURVEY; SPACE DENSITY; OPTICAL ATLAS; CARBON STARS; ROSAT; SEARCH; PHOTOMETRY AB Low-mass companions to high-mass stars are difficult to detect, which is partly why the binary fraction for high-mass stars is still poorly constrained. Low-mass companions can be detected more easily however, once high-mass stars turn into white dwarfs. These systems are also interesting as the progenitors of a variety of intensely studied interacting binary systems, like novae, CVs, symbiotics, Ba and CH giants, Feige 24-type systems, and dwarf carbon stars. We describe a near-IR photometric search for cool red dwarf companions to hot white dwarfs (WDs). IR photometry offers a sensitive test for low-mass main-sequence (MS) companions. Our sample of EUV-detected WDs offers several advantages over previous (largely proper motion-selected) WD samples: (1) the high WD temperatures (24,000 < T-eff < 70,000 K) insure excellent IR flux contrast with cool dwarfs; (2) the range of evolutionary parameter space occupied by the WDs is considerably narrowed; and (3) the random effects of the intervening ISM provide a complete but reasonably sized sample. While some composite systems have been found optically among WDs detected in recent EUV All-Sky Surveys, we develop an IR technique that probes farther down the main sequence, detecting yet more companions. We use detailed DA model atmosphere fits to optical spectra to predict K magnitudes and distances, against which we contrast our near-IR observations. Our photometric survey reveals 10 DAs with a significant excess in both J and K. Half are newly discovered and are most likely previously unrecognized binary systems. Neither the frequency of infrared excess nor the mass estimate of the red dwarf companion correlate with white dwarf mass, as might be expected if either the EUV detectability or mass of the white dwarfs were significantly affected by a companion. Infrared spectra of these systems should help to determine the mass and spectral type of the cool companions presumably causing the IR excess, leading to better estimates of the mass ratio distribution in binaries. Counting previously known binaries, and resolved pairs, we find the total binary fraction of the sample is at least a third. Since most WD progenitors had initial masses greater than or equal to 2 M., we thus provide a photometric measure of the binary fraction of high-mass stars that would be difficult to perform in high-mass main-sequence stars. We estimate that 90% of the companions are of type K or later. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. Dr Remeis Sternwarte, D-96049 Bamberg, Germany. RP Green, PJ (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 64 TC 32 Z9 32 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2000 VL 540 IS 2 BP 992 EP 1004 DI 10.1086/309379 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360DH UT WOS:000089650800032 ER PT J AU Luhman, KL Rieke, GH Young, ET Cotera, AS Chen, H Rieke, MJ Schneider, G Thompson, RI AF Luhman, KL Rieke, GH Young, ET Cotera, AS Chen, H Rieke, MJ Schneider, G Thompson, RI TI The initial mass function of low-mass stars and brown dwarfs in young clusters SO ASTROPHYSICAL JOURNAL LA English DT Article DE infrared : stars; stars : evolution; stars : formation; stars : low-mass, brown dwarfs; stars : luminosity function, mass function; stars : pre-main-sequence ID STELLAR LUMINOSITY FUNCTIONS; ORION TRAPEZIUM CLUSTER; MOLECULAR CLOUD CORES; ACCRETION DISKS; NEBULA CLUSTER; IMAGING SURVEY; GIANT PLANETS; SPECTRUM; OBJECTS; IC-348 AB We have obtained images of the Trapezium Cluster (140 " x 140 "; 0.3 pc x 0.3 pc) with the Hubble Space Telescope Near-Infrared Camera and Multi-Object Spectrometer (NICMOS). Combining these data with new ground-based K-band spectra (R = 800) and existing spectral types and photometry, we have constructed an H-R diagram and used it and other arguments to infer masses and ages. To allow comparison with the results of our previous studies of IC 348 and rho Oph, we first use the models of D'Antona & Mazzitelli. With these models, the distributions of ages of comparable samples of stars in the Trapezium, rho Oph, and IC 348 indicate median ages of similar to 0.4 Myr for the first two regions and similar to 1-2 Myr for the latter. The low-mass initial mass functions (IMFs) in these sites of clustered star formation are similar over a wide range of stellar densities (rho Oph, n = 0.2-1 x 10(3) pc(-3); IC 348, n = 1 x 10(3) pc(-3); Trapezium, n = 1-5 x 10(4) pc(-3)) and other environmental conditions (e.g., presence or absence of OB stars). With current data, we cannot rule out modest variations in the substellar mass functions among these clusters. We then make the best estimate of the true form of the IMF in the Trapezium by using the evolutionary models of Baraffe et al, and an empirically adjusted temperature scale and compare this mass function to recent results for the Pleiades and the held. All of these data are consistent with an IMF that is flat or rises slowly from the substellar regime to about 0.6 M. and then rolls over into a power law that continues from about 1 M, to higher masses with a slope similar to or somewhat larger than the Salpeter value of 1.35. For the Trapezium, this behavior holds from our completeness limit of similar to 0.02 M. and probably, after a modest completeness correction, even from 0.01-0.02 M.. These data include similar to 50 likely brown dwarfs. We test the predictions of theories of the IMF against (1) the shape of the IMF, which is not log-normal, in clusters and the field, (2) the similarity of the IMFs among young clusters, (3) the lowest mass observed for brown dwarfs, and (4) the suggested connection between the stellar IMF and the mass function of prestellar clumps. In particular, most models do not predict the formation of the moderately large numbers of isolated objects down to 0.01 M. that we find in the Trapezium. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. RP Luhman, KL (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 100 TC 228 Z9 228 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2000 VL 540 IS 2 BP 1016 EP 1040 DI 10.1086/309365 PN 1 PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360DH UT WOS:000089650800034 ER PT J AU Van Straaten, S Ford, EC Van der Klis, M Mendez, M Kaaret, P AF Van Straaten, S Ford, EC Van der Klis, M Mendez, M Kaaret, P TI Relations between timing features and colors in the X-ray binary 4U 0614+09 SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; stars : individual (4U 0614+09); stars : neutron; X-rays : stars ID QUASI-PERIODIC OSCILLATIONS; ROTATING NEUTRON-STARS; BURSTER 4U-0614+091; EXOSAT OBSERVATIONS; GENERAL-RELATIVITY; RXTE OBSERVATIONS; ATOLL SOURCES; SCORPIUS X-1; DISCOVERY; BEHAVIOR AB We study the correlations between timing and X-ray spectral properties in the low-mass X-ray binary 4U 0614+09 using a large (265 ks) data set obtained with the Rossi X-Ray Timing Explorer. We find strong quasi-periodic oscillations (QPOs) of the X-ray flux, like the kilohertz QPOs in many other X-ray binaries with accreting neutron stars, with frequencies ranging from 1329 Hz down to 418 Hz and perhaps as low as 153 Hz. We report the highest frequency QPO yet from any low-mass X-ray binary at 1329 +/- 4 Hz, which has implications for neutron star structure. This QPO has a 3.5 sigma single-trial significance; for an estimated 40 trials the significance is 2.4 sigma. Besides the kilohertz QPOs, the Fourier power spectra show four additional components: high-frequency noise (HFN), described by a broken power law with a break frequency between 0.7 and 45 Hz, very low frequency noise (VLFN), which is fitted as a power law below 1 Hz, and two broad Lorentzians with centroid frequencies varying from 6 to 38 Hz and from 97 to 158 Hz, respectively. We find strong correlations between the frequencies of the kilohertz QPOs, the frequency of the 6-38 Hz broad Lorentzian, the break frequency of the HFN, the strength of both the HFN and the VLFN, and the position of the source in the hard X-ray color versus intensity diagram. The frequency of the 97-158 Hz Lorentzian does not correlate with these parameters. We also find that the relation between power density and break frequency of the HFN is similar to that established for black hole candidates in the low state. We suggest that the changing mass accretion rate is responsible for the correlated changes in all these parameters. C1 Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Natl Univ La Plata, Fac Ciencias Astron & Geofis, RA-1900 La Plata, Argentina. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Van Straaten, S (reprint author), Univ Amsterdam, Astron Inst Anton Pannekoek, Kruislaan 403, NL-1098 SJ Amsterdam, Netherlands. EM straaten@astro.uva.nl RI Mendez, Mariano/C-8011-2012 OI Mendez, Mariano/0000-0003-2187-2708 NR 82 TC 88 Z9 88 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2000 VL 540 IS 2 BP 1049 EP 1061 DI 10.1086/309351 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360DH UT WOS:000089650800036 ER PT J AU Aulanier, G DeLuca, EE Antiochos, SK McMullen, RA Golub, L AF Aulanier, G DeLuca, EE Antiochos, SK McMullen, RA Golub, L TI The topology and evolution of the Bastille Day flare SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; Sun : flares; Sun : magnetic fields; Sun : UV radiation ID CORONAL MASS EJECTIONS; MAGNETIC RECONNECTION; TRANSITION REGION; SOLAR-FLARES; LOOP OSCILLATIONS; DELTA-SPOT; EXPLORER; FIELD; CONFIGURATIONS; ARCADES AB On 1998 July 14, a class M3 flare occurred at 12:55 UT in AR 8270 near disk center. Kitt Peak line-of-sight magnetograms show that the flare occurred in a delta spot. Mees vector magnetograms show a strong shear localized near a portion of the closed neutral line around the parasitic polarity of the 6 spot. Observations of the hare in 171, 195, and 1600 Angstrom have been obtained by TRACE, with similar or equal to 40 s temporal and 0." 5 spatial resolutions. They reveal that small-scale preflare loops above the sheared region expanded and disappeared for more than 1 hr before flare maximum. During the flare, bright loops anchored in bright ribbons form and grow. This occurs while large-scale dimmings, associated with large expanding loops, develop on both sides of the active region. This suggests that the flare was eruptive and was accompanied by a coronal mass ejection (CME). Magnetic field extrapolations reveal the presence of a null point in the corona, with its associated "spine" held line, and its "fan" surface surrounding the parasitic polarity. We show that while the whole event occurs, the intersections of the "fan" and the "spine" with the photosphere brighten and move continuously. The interpretation of the event shows that the magnetic evolution of the eruptive flare is strongly coupled with its surrounding complex topology. We discuss evidence supporting a "magnetic breakout" process for triggering this eruptive flare. We finally conclude that multipolar fields cannot be neglected in the study and modeling of the origin of CMEs in the corona. C1 USN, Res Lab, Washington, DC 20375 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. RP Aulanier, G (reprint author), USN, Res Lab, Code 7670, Washington, DC 20375 USA. RI Antiochos, Spiro/D-4668-2012; DeLuca, Edward/L-7534-2013; OI Antiochos, Spiro/0000-0003-0176-4312; DeLuca, Edward/0000-0001-7416-2895; Golub, Leon/0000-0001-9638-3082 NR 37 TC 181 Z9 183 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2000 VL 540 IS 2 BP 1126 EP 1142 DI 10.1086/309376 PN 1 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360DH UT WOS:000089650800045 ER PT J AU Brown, WR Kenyon, SJ Geller, MJ Fabricant, DG AF Brown, WR Kenyon, SJ Geller, MJ Fabricant, DG TI UV excess galaxies: Wolf-Rayet galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : photometry; galaxies : starburst; stars : Wolf-Rayet; ultraviolet : galaxies ID REDSHIFT SURVEY; STAR-FORMATION; LUMINOSITY FUNCTION; K-CORRECTIONS; ULTRAVIOLET; EVOLUTION; CATALOG; SPECTRA; COUNTS; MODELS AB We discuss V- and R-band photometry for 67% of the recent SA 57 ultraviolet-selected galaxy sample of M. Sullivan and collaborators. In a sample of 176 W-selected galaxies, Sullivan et al. find that 24% have (UV -B) colors too blue for consistency with starburst spectral synthesis models. We propose that these extreme blue, UV excess galaxies are Wolf-Rayet (W-R) galaxies, starburst galaxies with strong UV emission from W-R stars. We measure a median (V-R) = 0.38 +/- 0.06 for the UV-selected sample, bluer than a sample optically selected at R but consistent with starburst and W-R galaxy colors. We demonstrate that redshifted W-R emission lines can double or triple the flux through the UV bandpass at high redshifts. Thus, the (UV-B) color of a WR galaxy can be up to 1.3 mag bluer at high redshift, and the expected selection function is skewed to larger redshifts. The redshift distribution of the extreme blue, UV excess galaxies matches the selection function we predict from the properties of W-R galaxies. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Brown, WR (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 29 TC 5 Z9 5 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2000 VL 540 IS 2 BP L83 EP L86 DI 10.1086/312878 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360DJ UT WOS:000089650900005 ER PT J AU Moran, EC Barth, AJ Kay, LE Filippenko, AV AF Moran, EC Barth, AJ Kay, LE Filippenko, AV TI The frequency of polarized broad emission lines in type 2 Seyfert galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : individual (NGC 424, NGC 591, NGC 2273, NGC 3081, NGC 4507); galaxies : Seyfert-polarization ID ACTIVE GALACTIC NUCLEI; RADIO STRUCTURES; SPECTROPOLARIMETRY; REGIONS; SAMPLE AB We have discovered polarized broad emission lines in five type 2 Seyfert galaxies (NGC 424, NGC 591, NGC 2273, NGC 3081, and NGC 4507), establishing that these objects are type 1 Seyferts obscured by dense circumnuclear material. The galaxies are part of a distance-limited sample of 31 Seyfert 2s, for which spectropolarimetric observations are now complete. Combined with published reports, our results indicate that at least 11 of the galaxies in this sample, or greater than or equal to 35%, possess hidden broad-line regions. As the first reliable estimate of the frequency of polarized broad emission lines in type 2 Seyfert galaxies, this has important implications for the general applicability of Seyfert unification models. C1 Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Columbia Univ, Dept Phys & Astron, Barnard Coll, New York, NY 10027 USA. RP Moran, EC (reprint author), Univ Calif Berkeley, Dept Astron, 601 Campbell Hall, Berkeley, CA 94720 USA. NR 26 TC 98 Z9 98 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2000 VL 540 IS 2 BP L73 EP L77 DI 10.1086/312876 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360DJ UT WOS:000089650900003 ER PT J AU Schwartz, DA Marshall, HL Lovell, JEJ Piner, BG Tingay, SJ Birkinshaw, M Chartas, G Elvis, M Feigelson, ED Ghosh, KK Harris, DE Hirabayashi, H Hooper, EJ Jauncey, DL Lanzetta, KM Mathur, S Preston, RA Tucker, WH Virani, S Wilkes, B Worrall, DM AF Schwartz, DA Marshall, HL Lovell, JEJ Piner, BG Tingay, SJ Birkinshaw, M Chartas, G Elvis, M Feigelson, ED Ghosh, KK Harris, DE Hirabayashi, H Hooper, EJ Jauncey, DL Lanzetta, KM Mathur, S Preston, RA Tucker, WH Virani, S Wilkes, B Worrall, DM TI Chandra discovery of a 100 kiloparsec X-ray jet in PKS 0637-752 SO ASTROPHYSICAL JOURNAL LA English DT Article DE quasars : individual (PKS 0637-752); radio continuum : galaxies; X-rays : galaxies ID VLBI OBSERVATIONS; RADIO-SOURCES AB The quasar PKS 0637-752, the first celestial X-ray target of the Chandra X-Ray Observatory, has revealed asymmetric X-ray structure extending from 3" to 12" west of the quasar, coincident with the inner portion of the jet previously detected in a 4.8 GHz radio image (Tingay et al. 1998). At a redshift of z = 0.651, the jet is the largest (greater than or similar to 100 kpc in the plane of the sky) and most luminous (similar to 10(44.6) ergs s(-1)) of the few so far detected in X-rays. This Letter presents a high-resolution X-ray image of the jet, from 42 ks of data when PKS 0637-752 was on-axis and ACIS-S was near the optimum focus. For the inner portion of the radio jet, the X-ray morphology closely matches that of new Australian Telescope Compact Array radio images at 4.8 and 8.6 GHz. Observations of the parsec-scale core using the very long baseline interferometry space observatory program mission show structure aligned with the X-ray jet, placing important constraints on the X-ray source models. Hubble Space Telescope images show that there are three small knots coincident with the peak radio and X-ray emission. Two of these are resolved, which we use to estimate the sizes of the X-ray and radio knots. The outer portion of the radio jet and a radio component to the east show no X-ray emission to a limit of about 100 times Lower flux. The X-ray emission is difficult to explain with models that successfully account for extranuclear X-ray/radio structures in other active galaxies. We think the most plausible is a synchrotron self-Compton model, but this would imply extreme departures from the conventional minimum energy and/or homogeneity assumptions. We also rule out synchrotron or thermal bremsstrahlung models for the jet X-rays, unless multicomponent or ad hoc geometries are invoked. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. CSIRO, Australia Telescope Natl Facil, Epping, NSW 2121, Australia. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Bristol, Dept Phys, Bristol BS8 1TL, Avon, England. Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. RP Schwartz, DA (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Tingay, Steven/B-5271-2013 NR 20 TC 85 Z9 85 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2000 VL 540 IS 2 BP L69 EP L72 DI 10.1086/312875 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360DJ UT WOS:000089650900002 ER PT J AU Pojeta, J AF Pojeta, J TI Tyrannosaurus Sue - The extraordinary saga of the largest, most fought over T. rex ever found SO SCIENCE LA English DT Book Review C1 Smithsonian Inst, Dept Paleobiol, US Geol Survey, Washington, DC 20560 USA. RP Pojeta, J (reprint author), Smithsonian Inst, Dept Paleobiol, US Geol Survey, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD SEP 8 PY 2000 VL 289 IS 5485 BP 1695 EP 1696 DI 10.1126/science.289.5485.1695 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 352BT UT WOS:000089195200028 ER PT J AU Jaksch, D Cirac, JI Zoller, P Rolston, SL Cote, R Lukin, MD AF Jaksch, D Cirac, JI Zoller, P Rolston, SL Cote, R Lukin, MD TI Fast quantum gates for neutral atoms SO PHYSICAL REVIEW LETTERS LA English DT Article ID FROZEN RYDBERG GAS AB We propose several schemes fur implementing a fast two-qubit quantum gate Fur neutral atoms with the gate operation time much faster than the time scales associated with the external motion of the atoms in the trapping potential. In our example, the large interaction energy required to perform fast gate operations is provided by the dipole-dipole interaction of atoms excited to low-lying Rydberg states in constant electric fields. A detailed analysis of imperfections: of the gate operation is given. C1 Univ Innsbruck, Inst Theoret Phys, A-6020 Innsbruck, Austria. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. Harvard Smithsonian Ctr Astrophys, ITAMP, Cambridge, MA 02138 USA. RP Jaksch, D (reprint author), Univ Innsbruck, Inst Theoret Phys, Technikerstr 25, A-6020 Innsbruck, Austria. RI Jaksch, Dieter/F-1964-2010; rolston, steven/L-5175-2013; Zoller, Peter/O-1639-2014 OI rolston, steven/0000-0003-1671-4190; Zoller, Peter/0000-0003-4014-1505 NR 17 TC 691 Z9 701 U1 5 U2 46 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 4 PY 2000 VL 85 IS 10 BP 2208 EP 2211 DI 10.1103/PhysRevLett.85.2208 PG 4 WC Physics, Multidisciplinary SC Physics GA 349VC UT WOS:000089065400043 ER PT J AU Arnoldi, MJ AF Arnoldi, MJ TI African puppetry at the heart of African performance SO AFRICAN ARTS LA English DT Book Review C1 Smithsonian Inst, Washington, DC 20560 USA. RP Arnoldi, MJ (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU UNIV CALIF PI LOS ANGELES PA AFRICAN STUDIES CNTR, LOS ANGELES, CA 90024 USA SN 0001-9933 J9 AFR ARTS JI Afr. Arts PD FAL PY 2000 VL 33 IS 3 BP 12 EP 13 DI 10.2307/3337684 PG 2 WC Art SC Art GA 377AN UT WOS:000165489900004 ER PT J AU Arnoldi, MJ AF Arnoldi, MJ TI Renewing tradition: The revitalization of Bogolan in Mali and abroad SO AFRICAN ARTS LA English DT Art Exhibit Review C1 Smithsonian Inst, Washington, DC 20560 USA. RP Arnoldi, MJ (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 4 TC 0 Z9 0 U1 0 U2 2 PU UNIV CALIF PI LOS ANGELES PA AFRICAN STUDIES CNTR, LOS ANGELES, CA 90024 USA SN 0001-9933 J9 AFR ARTS JI Afr. Arts PD FAL PY 2000 VL 33 IS 3 BP 80 EP 82 PG 3 WC Art SC Art GA 377AN UT WOS:000165489900012 ER PT J AU Pogue, MG Passoa, S AF Pogue, MG Passoa, S TI Spodoptera ochrea (Lepidoptera : Noctuidae): a new host record (Asparagus) from Peru and description of the female genitalia SO ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA LA English DT Article DE Spodoptera; asparagus; plant hosts; pest; female genitalia AB Spodoptera ochrea (Hampson) was recently reared on a new host, asparagus (Asparagus officinalis L.), in Peru. Other host plants include cotton, tobacco, and potatoes in Peru. Distribution is restricted to the dry west coast of southern Ecuador and Peru. The female genitalia is illustrated and described for the first time. Additional records of asparagus feeding Spodoptera are discussed. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Entomol, USDA ARS,PSI,Systemat Entomol Lab, Washington, DC 20560 USA. Ohio State Univ, Anim & Plant Hlth Inspect Serv, Plant Protect Quarantine, USDA, Columbus, OH 43212 USA. RP Pogue, MG (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Entomol, USDA ARS,PSI,Systemat Entomol Lab, Washington, DC 20560 USA. NR 14 TC 1 Z9 1 U1 0 U2 2 PU ENTOMOL SOC AMER PI LANHAM PA 9301 ANNAPOLIS RD, LANHAM, MD 20706 USA SN 0013-8746 J9 ANN ENTOMOL SOC AM JI Ann. Entomol. Soc. Am. PD SEP PY 2000 VL 93 IS 5 BP 1019 EP 1021 DI 10.1603/0013-8746(2000)093[1019:SOLNAN]2.0.CO;2 PG 3 WC Entomology SC Entomology GA 359VG UT WOS:000089632300002 ER PT J AU Myers, KJ AF Myers, KJ TI Art and commerce in Jacksonian America: The steamboat "Albany" collection SO ART BULLETIN LA English DT Article AB When the Stevens family from Hoboken, New Jersey, commissioned twelve paintings by seven leading American artists in 1826 and then installed them in its new Hudson River steamboat, the Albany, it constituted one of the earliest important instances of arts patronage by a private business in the United States. The Albany collection included paintings by Birch, Doughty, Cole, Vanderlyn, Sully, and Morse. In this essay, I reconstruct this historically influential collection and explore its significance for the Stevenses who commissioned it, for the artists who contributed to it, and for travelers who could have seen it in its original installation. C1 Smithsonian Inst, Freer Gallery Art, Washington, DC 20560 USA. RP Myers, KJ (reprint author), Smithsonian Inst, Freer Gallery Art, Washington, DC 20560 USA. NR 22 TC 2 Z9 2 U1 0 U2 0 PU COLLEGE ART ASSOC PI NEW YORK PA 275 SEVENTH AVE, NEW YORK, NY 10001 USA SN 0004-3079 J9 ART BULL JI Art Bull. PD SEP PY 2000 VL 82 IS 3 BP 503 EP 528 DI 10.2307/3051399 PG 26 WC Art SC Art GA 606CN UT WOS:000178715800006 ER PT J AU Duc, PA Brinks, E Springel, V Pichardo, B Weilbacher, P Mirabel, IF AF Duc, PA Brinks, E Springel, V Pichardo, B Weilbacher, P Mirabel, IF TI Formation of a tidal dwarf galaxy in the interacting system Arp 245 (NGC 2992/93) SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : individual (Arp 245, NGC 2992, NGC 2993, FGC 0938); galaxies : interactions; methods : numerical ID H-II REGIONS; STAR-FORMATION; SEYFERT-GALAXIES; IRREGULAR GALAXIES; CHEMICAL ABUNDANCES; OPTICAL STRUCTURE; SPIRAL GALAXIES; ACTIVE GALAXIES; DISK GALAXIES; LINE RATIOS AB Among the various phenomena observed in interacting galaxies is the ejection due to tidal forces of stellar and gaseous material into the intergalactic medium and its subsequent rearranging which can lead to the formation of self-gravitating tidal dwarf galaxies (TDGs). We investigate this process with a detailed multiwavelength study of the interacting system Arp 245 and a numerical model of the collision computed with a Tree-SPH code. Our observations consist of optical/near-infrared broadband imaging, Ha! imaging, optical spectroscopy, H I VLA cartography and CO line mapping. The system, composed of the two spiral galaxies NGC 2992 and NGC 2993, is observed at an early stage of the interaction, about 100 Myr after perigalacticon, though at a time when tidal tails have already developed. The VLA observations disclose a third partner to the interaction: an edge-on, flat galaxy, FGC 0938, which looks strikingly undisturbed and might just be falling toward the NGC 2992/93 system. Our H I map shows prominent counterparts to the optical tails. Whereas the stellar and gaseous components of the plume that originates from NGC 2992 match, the stellar and H I tails emanating from NGC 2993 have a different morphology. In particular, the H I forms a ring, a feature that has been successfully reproduced by our numerical simulations. The H I emission in the system as a whole peaks at the tip of the NGC 2992 tail where a gas reservoir of about 10(9) M(circle dot), about 60% of the H I toward NGC 2992, coincides with a star-forming optical condensation, A245N. The latter tidal object exhibits properties ranging between those of dwarf irregular galaxies (structural parameters, gas content, star formation rate) and those of spiral disks (metallicity, star formation efficiency, stellar population). Although it is likely, based on our analysis of the H I and model data cube, that A245N might become an independent dwarf galaxy, the dynamical evidence is still open to debate. Prompted by the questions raised for this particular object, we discuss some issues related to the definition and identification of TDGs and highlight some specific conditions which seem required to form them. Finally, we outline what is needed in terms of future numerical simulations in order to further our understanding of these objects. C1 CNRS URA 2052, F-91191 Gif Sur Yvette, France. CEA Saclay, DSM, DAPNIA, Serv Astrophys, F-91191 Gif Sur Yvette, France. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Dept Astron, Guanajuato 36000, Mexico. Max Planck Inst Astrophys, D-85740 Garching, Germany. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Nacl Autonoma Mexico, Inst Astron, Mexico City, DF, Mexico. CEA Saclay, DSM, DAPNIA, Serv Astrophys, D-37083 Gottingen, Germany. CEA Saclay, DSM, DAPNIA, Serv Astrophys, F-91191 Gif Sur Yvette, France. IAFE, RA-1948 Buenos Aires, DF, Argentina. RP Duc, PA (reprint author), CNRS URA 2052, F-91191 Gif Sur Yvette, France. EM paduc@cea.fr NR 95 TC 141 Z9 141 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD SEP PY 2000 VL 120 IS 3 BP 1238 EP 1264 DI 10.1086/301516 PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360LX UT WOS:000089670300007 ER PT J AU Haisch, KE Lada, EA Lada, CJ AF Haisch, KE Lada, EA Lada, CJ TI A near-infrared L-band survey of the young embedded cluster NGC 2024 SO ASTRONOMICAL JOURNAL LA English DT Article DE infrared : stars; open clusters and associations : individual (NGC 2024); stars : formation ID AURIGA MOLECULAR CLOUD; CIRCUMSTELLAR DISKS; INTRINSIC COLORS; STELLAR OBJECTS; STAR-FORMATION; ORION-NEBULA; LOW-MASS; PHOTOMETRY; EXTINCTION; NGC-2024 AB We present the results of the first sensitive L-band (3.4 mu m) imaging study of the nearby young embedded cluster NGC 2024. Two separate surveys of the cluster were acquired in order to obtain a census of the circumstellar disk fraction in the cluster. We detected 257 sources to the m(L) less than or equal to 12.0 completeness limit of our similar to 110 arcmin(2) primary survey region. An additional 26 sources with 12.0 < L < 14.0 were detected in the deeper survey of the central similar to 6.25 arcmin(2) region of the cluster. From an analysis of the JHKL colors of all sources in our largest area, we find an infrared excess fraction of greater than or equal to 86% +/- 8 %. The JHKL colors suggest that the infrared excesses arise in circumstellar disks, indicating that the majority of the sources that formed in the NGC 2024 cluster are currently surrounded by, and likely formed with, circumstellar disks. The excess fractions remain very high, within the errors, even at the faintest L magnitudes from our deeper surveys, suggesting that disks form around the majority of the stars in very young clusters such as NGC 2024 independent of mass. From comparison with published JHKL observations of Taurus, we find the K-L excess fraction in NGC 2024 to be formally higher than in Taurus, although both fractions are quite high. Thus, existing L-band observations are consistent with a high initial incidence of circumstellar disks in both NGC 2024 and Taurus. Because NGC 2024 represents a region of much higher stellar density than Taurus, this suggests that disks may form around most of the YSOs in star-forming regions independent of environment. We find a relatively constant JHKL excess fraction with increasing cluster radius, indicating that the disk fraction is independent of location in the cluster. In contrast, the JHK excess fraction increases rapidly toward the central region of the cluster. The most likely cause for this increase is the contamination of the K-band measurements by bright nebulosity in the central regions of the cluster. This suggests that caution must be applied using only JHK-band observations to infer disk fractions in nebulous environments. Finally, we identify 45 candidate protostellar sources in the central regions of the cluster, and we find a lower limit on the protostellar phase of early stellar evolution in the NGC 2024 cluster of 0.4-1.4 x 10(5) yr, similar to that in Taurus. C1 Univ Florida, Dept Astron, Gainesville, FL 32611 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. RP Haisch, KE (reprint author), Univ Florida, Dept Astron, 211 SSRB, Gainesville, FL 32611 USA. NR 41 TC 83 Z9 83 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD SEP PY 2000 VL 120 IS 3 BP 1396 EP 1409 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360LX UT WOS:000089670300018 ER PT J AU Matheson, T Filippenko, AV Barth, AJ Ho, LC Leonard, DC Bershady, MA Davis, M Finley, DS Fisher, D Gonzalez, RA Hawley, SL Koo, DC Li, WD Lonsdale, CJ Schlegel, D Smith, HE Spinrad, H Wirth, GD AF Matheson, T Filippenko, AV Barth, AJ Ho, LC Leonard, DC Bershady, MA Davis, M Finley, DS Fisher, D Gonzalez, RA Hawley, SL Koo, DC Li, WD Lonsdale, CJ Schlegel, D Smith, HE Spinrad, H Wirth, GD TI Optical spectroscopy of supernova 19935 during its first 2500 days SO ASTRONOMICAL JOURNAL LA English DT Review DE binaries : close; stars : evolution; stars : mass loss; supernovae : general; supernovae : individual (SN 1993J) ID LARGE MAGELLANIC CLOUD; EARLY-TIME SPECTRA; SN 1993J; IIB SUPERNOVA; X-RAYS; UBVRI PHOTOMETRY; IB SUPERNOVAE; LIGHT CURVES; CIRCUMSTELLAR INTERACTION; INTERGALACTIC GAS AB We present 42 low-resolution spectra of supernova (SN) 1993J, our complete collection from the Lick and Keck observatories, from day 3 after explosion to day 2454, as well as one Keek high-dispersion spectrum from day 383. SN 1993J began as an apparent SN II, albeit an unusual one. After a few weeks, a dramatic transition took place, as prominent helium lines emerged in the spectrum. SN 1993J had metamorphosed from a SN II to a SN IIb Nebular spectra of SN 1993J closely resemble those of SNe Ib and Ic, but with a persistent H alpha line. At very late times, the H alpha emission line dominated the spectrum, but with an unusual, boxlike profile. This is interpreted as an indication of circumstellar interaction. C1 Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. Univ Wisconsin, Dept Astron, Madison, WI 53706 USA. Eureka Sci Inc, Oakland, CA USA. Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. Observ Geneva, CH-1290 Sauverny, Switzerland. Univ Washington, Dept Astron, Seattle, WA 98195 USA. CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. Univ Calif San Diego, Ctr Astrophys & Space Sci, La Jolla, CA 92093 USA. WM Keck Observ, Kamuela, HI 96743 USA. RP Matheson, T (reprint author), Univ Calif Berkeley, Dept Astron, 601 Campbell Hall, Berkeley, CA 94720 USA. NR 105 TC 65 Z9 65 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD SEP PY 2000 VL 120 IS 3 BP 1487 EP 1498 DI 10.1086/301518 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360LX UT WOS:000089670300025 ER PT J AU Matheson, T Filippenko, AV Ho, LC Barth, AJ Leonard, DC AF Matheson, T Filippenko, AV Ho, LC Barth, AJ Leonard, DC TI Detailed analysis of early to late-time spectra of supernova 1993J SO ASTRONOMICAL JOURNAL LA English DT Review DE circumstellar matter; stars : mass loss; supernovae : general; supernovae : individual (SN 1993J); techniques : spectroscopic ID O-I LAMBDA-LAMBDA-6300; HELIUM STAR MODELS; SN 1993J; OPTICAL-SPECTRA; CIRCUMSTELLAR INTERACTION; HYDRODYNAMIC INSTABILITIES; ULTRAVIOLET EXTINCTION; OXYGEN DISTRIBUTION; UBVRI PHOTOMETRY; VELA SUPERNOVA AB We present a detailed study of line structure in early to late-time spectra of supernova (SN) 1993J. Spectra during the nebular phase, but within the first two years after explosion, exhibit small-scale structure in the emission lines of some species, notably oxygen and magnesium, showing that the ejecta of SN 1993J are clumpy. On the other hand, a lack of structure in emission lines of calcium implies that the source of calcium emission is uniformly distributed throughout the ejecta. These results are interpreted as evidence that oxygen emission originates in clumpy, newly synthesized material, while calcium emission arises from material preexisting in the atmosphere of the progenitor. Spectra spanning the range 433-2454 days after the explosion show boxlike profiles for the emission lines, clearly indicating circumstellar interaction in a roughly spherical shell. This is interpreted within the Chevalier & Fransson model for SNe interacting with mass lost during prior stellar winds. At very late times, the emission lines have a two-horned profile, implying the formation of a somewhat flattened or disklike structure that is a significant source of emission. The very high signal-to-noise ratio spectra are used to demonstrate the potential significance of misinterpretation of telluric absorption lines in the spectra of bright SNe. C1 Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Matheson, T (reprint author), Univ Calif Berkeley, Dept Astron, 601 Campbell Hall, Berkeley, CA 94720 USA. EM matheson@astron.berkeley.edu; alex@astron.berkeley.edu; lho@ociw.edu; abarth@cfa.harvard.edu; leonard@astron.berkeley.edu NR 105 TC 154 Z9 154 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD SEP PY 2000 VL 120 IS 3 BP 1499 EP 1515 DI 10.1086/301519 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 360LX UT WOS:000089670300026 ER PT J AU Boirin, L Barret, D Olive, JF Bloser, PF Grindlay, JE AF Boirin, L Barret, D Olive, JF Bloser, PF Grindlay, JE TI Low and high frequency quasi-periodic oscillations in 4U1915-05 SO ASTRONOMY & ASTROPHYSICS LA English DT Review DE stars : individual : 4U1915-05; stars : neutron; X-rays : stars ID X-RAY BINARIES; NEUTRON-STAR; CYGNUS X-2; RELATIVISTIC PRECESSION; TIMING BEHAVIOR; BEAT-FREQUENCY; CIRCINUS X-1; GX 17+2; DISCOVERY; GINGA AB The X-ray burster and dipper 4U1915-05 (also known as XB 1916-053) was observed 19 times for a total exposure of roughly 140 ks between 1996 February and October with the proportional counter array (PCA) aboard Rossi X-ray Timing Explorer (RXTE). We present here the detailed timing study of its X-ray emission. The source was observed in both a high intensity/soft spectral and a low intensity/hard spectral state. The 2-20 keV luminosities are about 1.4 x 10(37) and 3.2 x 10(36) ergs s(-1) in the two regimes respectively (assuming a source distance of 9.3 kpc). We confirm that 4U1915-05 is an atoll source based on its spectral behaviour and its aperiodic variability in the frequency range similar to 4 x 10(-3) - 128 Hz. 4U1915-05 displays red noise below similar to 1 Hz, but is especially remarkable for its quasi-periodic variability detected for the first time at several timescales. We detect low frequency quasi-periodic oscillations (LFQPOs) between similar to 5 and 80 Hz, as well as high frequency QPOs (HFQPOs) between similar to 200 and 1300 Hz. Both LFQPOs and HFQPOs frequencies positively correlate with the mass accretion rate inferred from the position of the source on the color-color diagram. In a narrow range of luminosity, we also detect twin simultaneous HFQPOs separated by 348 +/- 12 Hz. C1 UPS, CNRS, Ctr Etud Spatiale Rayonnements, F-31028 Toulouse 04, France. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Boirin, L (reprint author), UPS, CNRS, Ctr Etud Spatiale Rayonnements, 9 Ave Colonel Roche, F-31028 Toulouse 04, France. EM boirin@cesr.fr NR 102 TC 48 Z9 48 U1 0 U2 3 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 2000 VL 361 IS 1 BP 121 EP 138 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 357PT UT WOS:000089510600019 ER PT J AU Abel, T Bryan, GL Norman, ML AF Abel, T Bryan, GL Norman, ML TI The formation and fragmentation of primordial molecular clouds SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : theory; galaxies : formation; methods : numerical ID ADAPTIVE MESH REFINEMENT; POPULATION-III STARS; DARK-MATTER; HYDRODYNAMICS; EVOLUTION; HYDROGEN; UNIVERSE; OBJECTS; MODELS; GAS AB Many questions in physical cosmology regarding the thermal history of the intergalactic medium, chemical enrichment, reionization, etc., are thought to be intimately related to the nature and evolution of pregalactic structure. In particular, the efficiency of primordial star formation and the primordial initial mass function are of special interest. We present results from high-resolution three-dimensional adaptive mesh refinement simulations that follow the collapse of primordial molecular clouds and their subsequent fragmentation within a cosmologically representative volume. Comoving scales from 128 kpc down to 1 pc are followed accurately. Dark matter dynamics, hydrodynamics, and all relevant chemical and radiative processes (cooling) are followed self-consistently for a cluster-normalized cold dark matter (CDM) structure formation model. Primordial molecular clouds with similar to 10(5) solar masses are assembled by mergers of multiple objects that have formed hydrogen molecules in the gas phase with a fractional abundance of less than or similar to 10(-4). As the subclumps merge, cooling lowers the temperature to similar to 200 K in a "cold pocket" at the center of the halo. Within this cold pocket, a quasi-hydrostatically contracting core with mass similar to 200 M. and number densities greater than or similar to 10(5) cm(-3) are found. We find that less than 1% of the primordial gas in such small-scale structures cools and collapses to sufficiently high densities to be available for primordial star formation. Furthermore, it is worthwhile to note that this study achieved the highest dynamic range covered by structured adaptive mesh techniques in cosmological hydrodynamics to date. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. MIT, Cambridge, MA 02139 USA. Univ Illinois, Natl Ctr Supercomp Applicat, LCA, Urbana, IL 61801 USA. Univ Illinois, Dept Astron, Urbana, IL 61801 USA. RP Abel, T (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 33 TC 439 Z9 440 U1 0 U2 7 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2000 VL 540 IS 1 BP 39 EP 44 DI 10.1086/309295 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 356CW UT WOS:000089427600005 ER PT J AU Colley, WN Schild, RE AF Colley, WN Schild, RE TI Hourly variability in Q0957+561 SO ASTROPHYSICAL JOURNAL LA English DT Article DE dark matter; galaxies : halo; gravitational lensing; methods : data analysis; quasars : individual (0957+561); techniques : photometric ID TIME-DELAY; QUASAR Q0957+561; PHOTOMETRY; A,B AB We have continued our effort to re-reduce archival Q0957+561 brightness monitoring data and present results for 1629 R-band images using the methods of galaxy subtraction and seeing correction that we reported previously. The new data set comes from four observing runs, several nights apiece, with sampling of typically 5 minutes, which allows the first measurement of the structure function for variations in the R band from timescales of hours to years. Comparison of our reductions to previous reductions of the same data and to r-band photometry produced at Apache Point Observatory shows good overall agreement. Two of the data runs, separated by 417 days, allow us for the first time to use intranight variations to estimate the time delay. However, our sharpened value of 417.4 days is valid only if the time delay is close to the now-fashionable 417 day value, and worse, it is highly subject to diurnal windowing effects: our statistical estimators have little discriminatory power where there is no overlap of data, namely, at half-day offsets. Results herein show no unambiguous signature of daily microlensing, though a suggestive feature is found in the data. Because both time delay measurement and microlensing searches suffer from the lack of sampling at half-day offsets, inevitable at a single observatory, we discuss the need for round-the-clock monitoring with participation by multiple observatories. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Colley, WN (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 16 TC 15 Z9 15 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2000 VL 540 IS 1 BP 104 EP 112 DI 10.1086/309305 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 356CW UT WOS:000089427600012 ER PT J AU Petrucci, PO Haardt, F Maraschi, L Grandi, P Matt, G Nicastro, F Piro, L Perola, GC De Rosa, A AF Petrucci, PO Haardt, F Maraschi, L Grandi, P Matt, G Nicastro, F Piro, L Perola, GC De Rosa, A TI Testing Comptonizing coronae on a long BeppoSAX observation of the Seyfert 1 galaxy NGC 5548 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : individual (NGC 5548); galaxies : Seyfert; radiation mechanisms : thermal ID ACTIVE GALACTIC NUCLEI; X-RAY-SPECTRUM; COLD MATTER; THERMAL COMPTONIZATION; ASTRONOMY SATELLITE; ASCA OBSERVATIONS; ON-BOARD; NGC-5548; MODEL; VARIABILITY AB We test accurate models of Comptonization spectra over the high-quality data of the BeppoSAX long look at NGC 5548, allowing for different geometries of the scattering region, different temperatures of the input soft photon field, and different viewing angles. We find that the BeppoSAX data are well represented by a plane-parallel or hemispherical corona viewed at an inclination angle of 30 degrees. For both geometries the best-fit temperature of the soft photons is close to 15(-9)(+3) eV. The corresponding best-fit values of the hot plasma temperature and optical depth are kT(e) similar or equal to 250-260 keV and tau similar or equal to 0.16-0.37 for the slab and hemisphere, respectively. These values are substantially different from those derived fitting the data with a power-law-plus-cutoff approximation to the Comptonization component (kT(e) less than or similar to 60 keV, tau similar or equal to 2.4). In particular, the temperature of the hot electrons estimated from Comptonization models is much larger. This is due to the fact that accurate Comptonization spectra in anisotropic geometries show "intrinsic" curvature that reduces the necessity of a high-energy cutoff. The Comptonization parameter derived for the slab model is larger than predicted for a two-phase plane-parallel corona in energy balance, suggesting that a more "photon-starved" geometry is necessary. The case of a hemispherical corona is consistent with energy balance but requires a large reflection component. The spectral softening detected during a flare that occurred in the central part of the observation corresponds to a decrease of the Comptonization parameter, probably associated with an increase of the soft photon luminosity, the hard photon luminosity remaining constant. The increased cooling fits in naturally with the derived decrease of the coronal temperature kT(e) in the high state. C1 Osserv Astron Brera, Milan, Italy. Univ Insubria, Como, Italy. CNR, Ist Astrofis Spaziale, Rome, Italy. Univ Roma 3, Rome, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Osservatorio Astron Roma, Rome, Italy. RP Petrucci, PO (reprint author), Osserv Astron Brera, Milan, Italy. RI PIRO, LUIGI/E-4954-2013; OI PIRO, LUIGI/0000-0003-4159-3984; Nicastro, Fabrizio/0000-0002-6896-1364; De Rosa, Alessandra/0000-0001-5668-6863 NR 44 TC 45 Z9 45 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2000 VL 540 IS 1 BP 131 EP 142 DI 10.1086/309319 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 356CW UT WOS:000089427600015 ER PT J AU Gordon, VD McCarthy, MC Apponi, AJ Thaddeus, P AF Gordon, VD McCarthy, MC Apponi, AJ Thaddeus, P TI Laboratory detection of HC6N, a carbon chain with a triplet electronic ground state SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : molecules; line : identification; methods : laboratory; molecular data; molecular processes; radio lines : ISM ID HCCN; SPECTROSCOPY; MOLECULES; HC4N AB A linear triplet isomer of HC6N has been detected by Fourier transform microwave spectroscopy in a supersonic molecular beam. A total of 85 hyperfine components from six rotational transitions between 8 and 18 GHz were measured to an uncertainty of 5 kHz; a similar set of transitions were detected for the N-15 isotopic species, produced using an isotopically enriched precursor gas sample. The spectroscopic constants for both species, including the fine and hyperfine coupling constants, were determined to very high accuracy, and these allow calculation of the radio spectrum to a fraction of 1 km s(-1) in equivalent radial velocity. Triplet HC6N is a highly polar, low-lying isomer; measurements show it to be about 10 times more abundant than a ring-chain isomer recently detected with the same spectrometer. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. RP Gordon, VD (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI McCarthy, Michael/0000-0001-9142-0008 NR 19 TC 14 Z9 17 U1 1 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2000 VL 540 IS 1 BP 286 EP 291 DI 10.1086/309321 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 356CW UT WOS:000089427600027 ER PT J AU Smith, N Jackson, JM Kraemer, KE Deutsch, LK Bolatto, A Hora, JL Fazio, G Hoffmann, WF Dayal, A AF Smith, N Jackson, JM Kraemer, KE Deutsch, LK Bolatto, A Hora, JL Fazio, G Hoffmann, WF Dayal, A TI Thermal infrared imaging of ultracompact HII regions in W49A SO ASTROPHYSICAL JOURNAL LA English DT Article DE HII regions; ISM : individual (W49A); stars : formation ID H-II REGIONS; CLOUD CORE; MASSIVE STARS; KINEMATICS; EMISSION; LINES; DUST AB Several compact radio continuum sources in W49A show detectable 8-20 mu m emission in MIRAC2 images obtained at the IRTF. In general, the infrared morphologies of these sources closely resemble the radio continuum emission. Spectral energy distributions indicate an infrared continuum excess above the level expected from free-free emission, consistent with thermal emission from dust grains heated to a few hundred K. The bright radio continuum sources concentrated at the western end of the ring of ultracompact Hn regions are not detected in the mid-infrared, while those at other positions in the ring are detected. This could be due to a localized region of high extinction along the line of sight. In addition, there are a few new infrared sources with no radio continuum counterparts. Finally, several infrared sources show strong 12.8 mu m [Ne II] emission, yielding neon abundances that are typically a few percent of the cosmic abundance of neon but are high considering the expected Ne++/Ne+ ratios for the range of spectral types of the ionizing sources. We conclude that the [Ne II] emission must come from shells around the ultracompact Hn regions, where the neon is able to survive as Ne+ rather than Ne++ because the radiation field has been softened by absorption of hard UV photons within the H II regions. C1 Univ Minnesota, Dept Astron, Minneapolis, MN 55455 USA. Boston Univ, Dept Astron, Boston, MA 02215 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. RP Smith, N (reprint author), Univ Minnesota, Dept Astron, 116 Church St SE, Minneapolis, MN 55455 USA. OI Hora, Joseph/0000-0002-5599-4650; Kraemer, Kathleen/0000-0002-2626-7155 NR 29 TC 11 Z9 11 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2000 VL 540 IS 1 BP 316 EP 331 DI 10.1086/309334 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 356CW UT WOS:000089427600030 ER PT J AU Welch, WJ Hartmann, L Helfer, T Briceno, C AF Welch, WJ Hartmann, L Helfer, T Briceno, C TI High-resolution, wide-field imaging of the HL Tauri environment in (CO)-C-13 (1-0) SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : bubbles; ISM : jets and outflows; ISM : molecules; stars : individual (HL Tauri, XZ Tauri); stars : pre-main-sequence ID MOLECULAR CLOUD CORES; STAR-FORMATION; YOUNG STARS; XZ TAURI; DISK; GAS; COLLAPSE; OUTFLOWS; NEBULOSITY; EVOLUTION AB We present a high-resolution image of the region near HL Tau in (CO)-C-13 (1-0) over a region of 3' made with the BIMA array, supplemented by data from the NRAO 12 m telescope to include emission structures with low spatial frequencies. We find evidence for a shell of dimensions similar to 2' x 1.'5 (similar to 0.08 x 0.06 pc), with XZ Tau being the closest known source to its center. The (CO)-C-13 map is consistent with an expanding bubble that has blown out on the far side from earth. Portions of the bubble wall are seen in optical scattered light. HL Tau is situated in the bubble wall; the evacuated region corresponds to the truncation in the reflection nebula northeast of HL Tau. Although it is thought that a remnant protostellar envelope is still infalling onto HL Tau, the existence of the expanding bubble makes it difficult to interpret the geometry and kinematics of the HL Tau circumstellar material. Our results demonstrate the importance of including low-spatial frequency emission for the interpretation of interferometer maps. C1 Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Univ Calif Berkeley, Radio Astron Lab, Berkeley, CA 94720 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Natl Radio Astron Observ, Tucson, AZ 85721 USA. Yale Univ, Dept Phys, New Haven, CT 06520 USA. RP Welch, WJ (reprint author), Univ Calif Berkeley, Dept Astron, 601 Campbell Hall, Berkeley, CA 94720 USA. NR 46 TC 28 Z9 28 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2000 VL 540 IS 1 BP 362 EP 371 DI 10.1086/309290 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 356CW UT WOS:000089427600033 ER PT J AU Wood, K Raymond, J AF Wood, K Raymond, J TI Resonant scattering of emission lines in coronal loops: Effects on image morphology and line ratios SO ASTROPHYSICAL JOURNAL LA English DT Article DE line : formation; radiative transfer; scattering; Sun : corona; Sun : X-rays, gamma rays ID X-RAY-LINES; FE-XVII; SOLAR CORONA; POLARIZATION; IONIZATION; SPECTRUM; OPACITY; PLASMAS AB We have investigated the effects of resonant scattering of emission lines on the image morphology and intensity from coronal loop structures. It has previously been shown that line-of-sight effects in optically thin line emission can yield loop images that appear uniformly bright at one viewing angle but show "looptop sources" at other viewing angles. For optically thick loops where multiple resonant scattering is important, we use a three-dimensional Monte Carlo radiation transfer code. Our simulations show that the intensity variation across the image is more uniform than the optically thin simulation, and depending on viewing angle the intensity may be lower or higher than that predicted from optically thin simulations due to scattering out of or into the line of sight. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM kenny@claymore.harvard.edu; jraymond@cfa.harvard.edu NR 23 TC 18 Z9 18 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2000 VL 540 IS 1 BP 563 EP 571 DI 10.1086/309336 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 356CW UT WOS:000089427600051 ER PT J AU Jha, S Charbonneau, D Garnavich, PM Sullivan, DJ Sullivan, T Brown, TM Tonry, JL AF Jha, S Charbonneau, D Garnavich, PM Sullivan, DJ Sullivan, T Brown, TM Tonry, JL TI Multicolor observations of a planetary transit of HD 209458 SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : eclipsing; planetary systems; stars : individual (HD 209458) techniques : photometric AB We present BVRIZ photometric observations of HD 209458 during the transit by its planetary companion on UT 1999 November 15 with the University of Hawaii 0.6 and 2.2 m telescopes and the High Altitude Observatory STARE telescope. The detailed shape of the transit curve is predicted to vary with color primarily as a result of the color-dependent limb darkening of the star but potentially due as well to the effect of color-dependent opacity in the planetary atmosphere. We model the light curves and present refined values for the transit timing and orbital period, useful for planning future observations of the planetary transit. We also derive significantly improved measurements of the planetary radius, R-p = 1.55 +/- 0.10 R-Jup, stellar radius, R-s = 1.27 +/- 0.05 R., and orbital inclination, i = 85.degrees 9 +/- 0.degrees 5. The derived planetary radius favors evolutionary models in which the planet has a low albedo. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Victoria Univ Wellington, Sch Chem & Phys Sci, Wellington, New Zealand. RP Jha, S (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 14 TC 48 Z9 48 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2000 VL 540 IS 1 BP L45 EP L48 DI 10.1086/312869 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 356CX UT WOS:000089427700012 ER PT J AU Scott, J Bechtold, J Dobrzycki, A AF Scott, J Bechtold, J Dobrzycki, A TI A uniform analysis of the Ly alpha forest at z=0-5. I. The sample and distribution of clouds at z > 1.7 SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE quasars : absorption lines ID HUBBLE-SPACE-TELESCOPE; LYMAN-LIMIT ABSORPTION; QUASI-STELLAR OBJECTS; LINE KEY PROJECT; BRIGHT QSO SURVEY; HIGH-RESOLUTION; INTERGALACTIC MEDIUM; MASS FLUCTUATIONS; GASEOUS EXTENT; ABSORBING GALAXIES AB We present moderate-resolution data for 39 quasi-stellar objects (QSOs) at z approximate to 2 obtained at the Multiple Mirror Telescope. These data are combined with spectra of comparable resolution of 60 QSOs with redshifts greater than 1.7 found in the literature to investigate the distribution of Ly alpha forest lines in redshift and equivalent width. We find a value for gamma, the parameter describing the number distribution of Ly alpha forest lines in redshift, of 1.88 +/- 0.22 for lines stronger than a rest equivalent width of 0.32 Angstrom in good agreement with some previous studies. The Kolmogorov-Smirnov test was applied to the data, and it is found that this single power law is a good fit over the relevant redshift ranges. Simulations of the Ly alpha forest were performed to determine the completeness of the line lists and to test how well the analysis recovers the underlying line statistics, given this level of completeness. C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Scott, J (reprint author), Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. NR 79 TC 17 Z9 18 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD SEP PY 2000 VL 130 IS 1 BP 37 EP 66 DI 10.1086/317339 PG 30 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 372LY UT WOS:000165236200002 ER PT J AU Scott, J Bechtold, J Dobrzycki, A Kulkarni, VP AF Scott, J Bechtold, J Dobrzycki, A Kulkarni, VP TI A uniform analysis of the Ly alpha forest at z=0-5. II. Measuring the mean intensity of the extragalactic ionizing background using the proximity effect SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE diffuse radiation; intergalactic medium; quasars : absorption lines ID HIGH-REDSHIFT QUASARS; RADIO-LOUD QUASARS; ULTRAVIOLET EMISSION PROPERTIES; ACTIVE GALACTIC NUCLEI; QSO ABSORPTION SYSTEMS; HUBBLE DEEP FIELD; C-IV-ABSORPTION; LUMINOSITY FUNCTION; HIGH-RESOLUTION; SPECTROSCOPIC SURVEY AB Moderate-resolution data for 40 quasi-stellar objects (QSOs) at z approximate to 2 were combined with spectra of comparable resolution of 59 QSOs with redshifts greater than 1.7 found in the literature to form a large, homogeneous sample of moderate-resolution (similar to1 Angstrom) QSO spectra. These spectra were presented and the statistics of the Ly alpha forest were discussed in Paper I. In this analysis, we demonstrate that a proximity effect is present in the data; i.e., there exists a significant (5.5 sigma) deficit of lines at z(abs) approximate to z(em). Within 1.5 h(-1) Mpc of the QSO emission redshift, the significance does depend on QSO luminosity, in accordance with the theory that this effect is caused by enhanced ionization of hydrogen in the vicinity of the QSO from UV photons from the QSO itself. The photoionization model of Bajtlik, Duncan, & Ostriker permits an estimate of the mean intensity of the extragalactic background radiation at the Lyman limit. We compare the results of this standard analysis with those obtained using a maximum likelihood technique. If the spectrum of the background is assumed to be identical to that of each individual QSO, and if this background is assumed to be constant over the redshift range 1.7 < z < 3.8, then the best-fit value for J(nu (0)) is found to be 1.4(-0.5)(+1.1) x 10(-21) ergs s(-1) cm(-2) Hz(-1) sr(-1), using QSO redshifts based on the Ly alpha emission line. Systemic QSO redshifts based on the [O III] lambda 5007 emission line for 19 objects in our sample show an average redshift of similar to 400 km s(-1) with respect to Ly alpha emission. Using redshifts based on [O III] or Mg II for the 35 objects for which they are measured and adding 400 km s(-1) to the remaining QSO Ly alpha redshifts gives a lower value of J(nu (0)), 7.0(-4.4)(+3.4) x 10(-22) ergs s(-1) cm(-2) Hz(-1) sr(-1). This value is in reasonable agreement with the predictions of various models of the ionizing background based on the integrated quasar luminosity function. Allowing for the fact that individual QSOs have different spectral indices that may also be different from that of the background, we use the standard methods to solve for the H I photoionization rate, Gamma, and the parameters describing its evolution with redshift. The best-fit value for the H I ionization rate we derive is 1.9(-1.0)(+1.2) x 10(-12) s(-1), in good agreement with models of the background that incorporate QSOs only. Finally, we use simulated Ly alpha forest spectra including the proximity effect to investigate curve-of-growth effects in the photoionization model used in the analysis. We find that the presence of lines on the saturated part of the curve of growth could cause our estimates of the background intensity to be overestimated by a factor of 2-3. This large absorption-line sample and these techniques for measuring the background and understanding the systematics involved allow us to place what we believe are the firmest limits on the background at these redshifts. C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Clemson Univ, Dept Phys & Astron, Clemson, SC 29634 USA. RP Scott, J (reprint author), Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. NR 96 TC 139 Z9 141 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD SEP PY 2000 VL 130 IS 1 BP 67 EP 89 DI 10.1086/317340 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 372LY UT WOS:000165236200003 ER PT J AU Karovska, M Wood, B Cook, JW Chen, J Howard, R AF Karovska, M Wood, B Cook, JW Chen, J Howard, R TI High angular resolution studies of coronal structures with SOHO SO ASTROPHYSICS AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT 8th UN/ESA Workshop on Basic Space Science: Scientific Exploration from Space CY MAR 13-17, 1999 CL AL AL BAYT UNIV, MAFRAQ, JORDAN SP UN, ESA HO AL AL BAYT UNIV ID MAGNETIC-FLUX ROPE; LASCO; HOLES; JETS; EIT AB Since January 1996, the Solar and Heliospheric Observatory (SOHO) has been providing unprecedented views of the extended solar corona to heliocentric distances of up to 32 solar radii. During the past three years we carried out studies of the morphology and dynamical evolution of various structures in the solar corona using two instruments on board SOHO: the Large Angle Spectrometric Coronagraph (LASCO) and the Extreme Ultraviolet Imaging Telescope (EIT). We have applied advanced image resolution enhancement techniques to explore in detail the characteristics of the small-scale structures and/or the low contrast structures in the solar corona. We describe here the results from these high-angular resolution studies, including of the kinematics of several Coronal Mass Ejections and polar jets. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. USN, Res Lab, Washington, DC 20375 USA. RP Karovska, M (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 10 TC 0 Z9 0 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0004-640X J9 ASTROPHYS SPACE SCI JI Astrophys. Space Sci. PD SEP PY 2000 VL 273 IS 1-4 BP 7 EP 15 DI 10.1023/A:1002635622083 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 366CN UT WOS:000089987400003 ER PT J AU Murakami, T Higashi, S Windsor, D AF Murakami, T Higashi, S Windsor, D TI Mating frequency, colony size, polyethism and sex ratio in fungus-growing ants (Attini) SO BEHAVIORAL ECOLOGY AND SOCIOBIOLOGY LA English DT Article DE attini; CAP-PCR DNA fingerprinting; polyandry; polyethism ID APIS-MELLIFERA L; SOLENOPSIS-INVICTA HYMENOPTERA; LEAF-CUTTER ANTS; SOCIAL HYMENOPTERA; EUSOCIAL HYMENOPTERA; FORMICA ANTS; PHYLOGENETIC ANALYSIS; POPULATION-STRUCTURE; MULTIPLE PATERNITY; GENETIC DIVERSITY AB The mating frequency of queens was estimated for eight attine ant species, Myrmicocrypta ednaella, Apterostigma mayri, Cyphomyrmex costatus, C. rimosus (four lower attines), Trachymyrmex isthmicus, Sericomyrmex amabalis, Acromyrmex octospinosus and Atta colombica (four higher attines), and correlated to colony size, worker polyethism, and sex ratio. Mating frequency was calculated from within-colony relatedness estimated by CAP-PCR DNA fingerprinting. Most queens of lower attines and T. isthmicus mated with only one male, while those of the three higher attines mated with multiple males. Mating frequency was positively correlated with colony size. Polyethism among workers was dependent on worker age in lower attines but on body size in higher attines, suggesting some correlation between mating frequency (i.e., within-colony gene diversity) and caste complexity. The sex ratio was biased toward females in species where the mating frequency equaled one, but toward males in species where the mating frequency was greater than two. Changing in nest site from ground surface to deep underground may have facilitated the evolution of large colony size in Attini, and this may have resulted in the evolution of polyandry (a queen mates with multiple males). With the evolution of polyandry in higher attines, Atta and Acromyrmex in particular have generated high genetic diversity within their colonies and complex social structures. C1 Kyoto Univ, Ctr Ecol Res, Kyoto, Japan. Hokkaido Univ, Grad Sch Environm Earth Sci, Sapporo, Hokkaido 060, Japan. Smithsonian Trop Res Inst, Balboa, Panama. RP Murakami, T (reprint author), Univ Texas, Austin, TX 78712 USA. NR 73 TC 49 Z9 50 U1 1 U2 21 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0340-5443 J9 BEHAV ECOL SOCIOBIOL JI Behav. Ecol. Sociobiol. PD SEP PY 2000 VL 48 IS 4 BP 276 EP 284 DI 10.1007/s002650000243 PG 9 WC Behavioral Sciences; Ecology; Zoology SC Behavioral Sciences; Environmental Sciences & Ecology; Zoology GA 357QE UT WOS:000089511700003 ER PT J AU Wendeln, MC Runkle, JR Kalko, EKV AF Wendeln, MC Runkle, JR Kalko, EKV TI Nutritional values of 14 fig species and bat feeding preferences in Panama SO BIOTROPICA LA English DT Article DE Barro Colorado Island; bats; carbohydrate; frugivory; lignin; minerals; protein tannin ID LOWLAND RAIN-FOREST; FRUIT-EATING BATS; ARTIBEUS-JAMAICENSIS; FRUGIVOROUS BIRDS; FOOD SELECTION; HOWLER MONKEYS; DISPERSERS; NITROGEN; CHOICE; FICUS AB Figs are a critical resource for many tropical frugivores, yet they often are referred to as low quality fruits. To determine their nutritional value, bath as a group and for individual species, we analyzed 14 fig species from Barro Colorado island (BCI), Panama, for fiber, tannins, lipids, protein, carbohydrates, amino acids, and minerals. Seeds and pulp were analyzed separately. Fig fruit pulp consisted of about one-third digestible components, mostly carbohydrates with some lipids and proteins. Tannin, lignin, and water-soluble carbohydrates showed considerable variation among species, as did fruit size. Figs contained high amounts of amino acids, such as leucine, lysine, valine, and arginine, and minerals, such as potassium, calcium, magnesium, sodium, and phosphorus. One species, Ficus insipida, contained the highest concentrations of almost all amino acids, many minerals, and protein. Small figs had as much nutritional value per gram as large figs. Free-standing figs had higher percentages of protein, complex carbohydrates, and ash than strangler figs, which had higher percentages of water-soluble carbohydrates, tannins, and hemicellulose. The guild of fruit-eating bats on BCI included ten common species with diets dominated by figs. Fecal analyses and captures at ripe fig trees showed a consistent pattern of resource partitioning. Small bats preferentially ate small-fruited and strangler figs while large bats consumed mostly large-fruited and free-standing figs. Small bats most often ate F. bullenei, which has high levels of lipid and carbohydrates, and F. yoponensis, which has high levels of protein. Medium and large bats most often ate F. insipida, a nutritionally superior species; their second most eaten species was F. obtusifolia, in which the large size may make it efficient to eat. Each bat ate a variety of fig species, supporting the idea that although no single species of fig may be sufficient to sustain frugivores, a mix of fig species can provide a complete set of nutrients. C1 Wright State Univ, Dept Biol Sci, Dayton, OH 45435 USA. Smithsonian Trop Res Inst, Balboa, Panama. RP Wendeln, MC (reprint author), Wright State Univ, Dept Biol Sci, Dayton, OH 45435 USA. NR 55 TC 89 Z9 96 U1 2 U2 20 PU ASSOC TROPICAL BIOLOGY INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 USA SN 0006-3606 J9 BIOTROPICA JI Biotropica PD SEP PY 2000 VL 32 IS 3 BP 489 EP 501 DI 10.1111/j.1744-7429.2000.tb00495.x PG 13 WC Ecology SC Environmental Sciences & Ecology GA 360DT UT WOS:000089651700012 ER PT J AU Buzas, MA Hayek, LAC AF Buzas, MA Hayek, LAC TI A case for long-term monitoring of the Indian River Lagoon, Florida: Foraminiferal densities, 1977-1996 SO BULLETIN OF MARINE SCIENCE LA English DT Article ID SPECIES DENSITIES; BIODIVERSITY; SEAGRASS; DIVERSITY; MACROBENTHOS; ABUNDANCE; ESTUARY AB Replicate observations on foraminiferal densities were made at a single station in the IRI, near the Harbor Branch Oceanographic Institution's jetty at Link Port, Florida during the 20-yr span, 1977-1996. At each sampling time, the densities of living (stained) individuals were recorded for five taxa in four replicates. During the years 1993 through 1996 sampling was on a monthly basis. Analyses of these data indicate a significant difference in density among years with 1994 exhibiting the lowest density for most (4 of 5) taxa. Seasonal differences were also significant for most (4 of 5) taxa with maximum densities in summer. For all taxa the interaction hypothesis for years by season was significant. During the 1970s and 1980s mostly summer data are available. Thus, we tested summer data only for yearly differences during the period 1993 through 1996. For all taxa, 1994 was a time of low densities. With this assurance, we proceeded to analyze equivalent data for the years 1977 thru 1996. In general, the years 1979 and 1994 were times of low densities while 1984 and 1987 were high. For all taxa, the 1980s had higher densities than the 1970s and 1990s, and taxa maintained the same rank order of abundance with no trend for an overall increase or decrease of densities evident. The seasonal and yearly observations of the pattern of foraminiferal densities are similar to those of the seagrasses and fish. However, the lack of similarity of sample timing, location, replication, and methods of analysis makes comparisons equivocal at best. Long-term monitoring by a number of specialists in different groups of organisms at the same times and places is needed. Before such simultaneous observations are begun, the researchers must all agree on a suitable statistical experimental design allowing for comprehensive analysis of the data. C1 Smithsonian Inst, Washington, DC 20560 USA. RP Buzas, MA (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 31 TC 9 Z9 10 U1 0 U2 2 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD SEP PY 2000 VL 67 IS 2 BP 805 EP 814 PG 10 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 371PD UT WOS:000165186600010 ER PT J AU Erwin, TL Johnson, PJ AF Erwin, TL Johnson, PJ TI Naming species, a new paradigm for crisis management in taxonomy: Rapid journal validation of scientific names enhanced with more complete descriptions on the Internet SO COLEOPTERISTS BULLETIN LA English DT Article ID MEXICO COLEOPTERA; DIVERSITY AB The process of taxonomic description and validation of names under the International Code of Zoological Nomenclature (Fourth Edition) is central to providing the anchor by which present and future seekers of knowledge attach and subsequently retrieve information about species and their phylogenetic associations. Since Linnaeus (1758), 4,400 +/- 363 species of insects have been described per year. If 25 to 30% of all species are beetles, and some 400,000 are estimated to be described to date, even taking the lower end of reasonable estimates at 8 to 10 million species of insects total, we still have more than 2 million beetle species yet to describe. At the current pace of some 3,154 beetle species described per year (1978 to present: BIOSIS, Zoological Record), we could "finish" the job in the year 3056 using the present system. While traditional descriptions published in widely circulated journals has been the mainstay of taxonomy and served the science well, we are entering a phase that might be called crisis management in taxonomy. This results from recent higher demands on taxonomists due to a general recognition that biodiversity is disappearing at an alarming rate, the so-called Sixth Extinction Crisis, and a reduced number of practicing descriptive taxonomists. Therefore, a new description paradigm that provides for rapid validation of new taxonomic names is paramount to plans for national biodiversity surveys. This new paradigm is elaborated and examples are given for both traditional and projected methods of species descriptions and rapid publication with additional extensive use of the Internet and server system to store and transmit more complete details and images. C1 Smithsonian Inst, Dept Entomol, Megadivers Grp, Washington, DC 20560 USA. RP Erwin, TL (reprint author), Smithsonian Inst, Dept Entomol, Megadivers Grp, NHB 169, Washington, DC 20560 USA. NR 30 TC 27 Z9 29 U1 3 U2 3 PU COLEOPTERISTS SOC PI NATCHEZ PA PO BOX 767, NATCHEZ, MS 39121 USA SN 0010-065X J9 COLEOPTS BULL JI Coleopt. Bull. PD SEP PY 2000 VL 54 IS 3 BP 269 EP 278 DI 10.1649/0010-065X(2000)054[0269:NSANPF]2.0.CO;2 PG 10 WC Entomology SC Entomology GA 367AH UT WOS:000090038700001 ER PT J AU Erwin, TL AF Erwin, TL TI A new genus and species of Lachnophorini and two new species of Lebiini from Costa Rica (Coleoptera : Carabidae) SO COLEOPTERISTS BULLETIN LA English DT Article AB A new genus and new species of Lachnophorini and 2 new species of Lebiini from Costa Rican are described (type localities in parentheses): Quammenis spectabilis, n, pen., n, sp. (type locality: COSTA PICA: Heredia Province, Estacion Magsasay, Parque Nacional Braulio Carrillo, 200m, LN264600,531100); Labia (Chelonodema) inbio, n. sp. (type locality: Guanacaste Province, Estacion Pitilla, 9 km S Santa Cecilia, 700 m, LN329950,380450 #4355): Ay, a Sola, n, sp, (type locality: Guanacaste Province, Estacion Pitilla, 9 km S Santa Cecilia, 700 m, LN329650,378600 #4600). C1 Smithsonian Inst, Dept Entomol, Megadivers Grp, Washington, DC 20560 USA. RP Erwin, TL (reprint author), Smithsonian Inst, Dept Entomol, Megadivers Grp, NHB 169, Washington, DC 20560 USA. NR 5 TC 7 Z9 6 U1 1 U2 2 PU COLEOPTERISTS SOC PI NATCHEZ PA PO BOX 767, NATCHEZ, MS 39121 USA SN 0010-065X J9 COLEOPTS BULL JI Coleopt. Bull. PD SEP PY 2000 VL 54 IS 3 BP 279 EP 283 DI 10.1649/0010-065X(2000)054[0279:ANGASO]2.0.CO;2 PG 5 WC Entomology SC Entomology GA 367AH UT WOS:000090038700002 ER PT J AU Wikelski, M Hau, M Wingfield, JC AF Wikelski, M Hau, M Wingfield, JC TI Seasonality of reproduction in a neotropical rain forest bird SO ECOLOGY LA English DT Review DE environmental cues; food supply; gonad growth; hormonal changes; Hylophylax n. naevioides; photoperiod; predictability of tropical seasons; rainfall; rain forest; seasonal reproduction; Spotted Antbird; tropics ID BROWED SPARROW WEAVER; OPPORTUNISTIC BREEDER; TERRITORIAL BEHAVIOR; PLOCEPASSER-MAHALI; LUTEINIZING-HORMONE; LOXIA-CURVIROSTRA; ANOURA-GEOFFROYI; RESIDENT BIRDS; NEST PREDATION; MATING SYSTEMS AB Tropical wet forests are commonly perceived as stable and constant environments. However, many rain forest organisms reproduce seasonally. To understand the proximate regulation of life history events in tropical organisms, we asked three questions: (1) How predictable are seasonal changes in the tropical rain forest? (2) Can tropical organisms anticipate environmental seasonality, despite the presumed lack of long-term environmental cues in near-equatorial areas? (3) What environmental cues can tropical organisms use? We studied Spotted Antbirds, monogamous understory insectivores, which started breeding in Panama (9 degrees N) in May (wet season) and continued until September/October. Breeding patterns were consistent between years, indicating that tropical seasons were as predictable for Spotted Antbirds (predictability 70%) as they are for many north temperate birds. Individual Spotted Antbirds shut down reproductive capacity (i.e., decreased gonad size) from October until February. In March, during the height of the dry season and about six weeks ahead of the wet season, gonads started to grow again. The growth rate of gonads was influenced by the amount of rainfall, which has been shown to correlate with food abundance. Gonad growth was paralleled by changes in luteinizing hormone, but not in testosterone, which remained at very low plasma levels year-round. The latter contrasts with the pattern for most migratory temperate-zone birds. Seasonal changes in reproductive activity correlated strongly with changes in the tropical photoperiod, but weakly with light intensity and rainfall, and nor with temperature. Thus, Spotted Antbirds likely anticipated rain forest seasonality using long-term cues (tropical photoperiod) and fine-tuned their reproductive activities using short-term cues (food/rainfall). The use of long-term environmental information could apply to most vertebrate species that live in the tropics. C1 Univ Washington, Dept Zool, Seattle, WA 98195 USA. Smithsonian Trop Res Inst, Balboa, Panama. RP Wikelski, M (reprint author), Princeton Univ, Dept Ecol & Evolutionary Biol, Guyot Hall, Princeton, NJ 08544 USA. EM wikelski@princeton.edu NR 118 TC 115 Z9 120 U1 5 U2 50 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1990 M STREET NW, STE 700, WASHINGTON, DC 20036 USA SN 0012-9658 EI 1939-9170 J9 ECOLOGY JI Ecology PD SEP PY 2000 VL 81 IS 9 BP 2458 EP 2472 DI 10.1890/0012-9658(2000)081[2458:SORIAN]2.0.CO;2 PG 15 WC Ecology SC Environmental Sciences & Ecology GA 350GW UT WOS:000089093500009 ER PT J AU Smith, DR Goulet, H AF Smith, DR Goulet, H TI Monosoma pulverata (Hymenoptera : Tenthredinidae), an alder-feeding sawfly new to North America SO ENTOMOLOGICAL NEWS LA English DT Article AB Monosoma pulverata, a European alder-feeding sawfly, is reported as new to North America from specimens taken in Newfoundland. It is separated from the only native North American species of Monosoma, M. inferentia. C1 Smithsonian Inst, Natl Museum Nat Hist, USDA ARS, PSI,Systemat Entomol Lab, Washington, DC 20560 USA. RP Smith, DR (reprint author), Smithsonian Inst, Natl Museum Nat Hist, USDA ARS, PSI,Systemat Entomol Lab, Washington, DC 20560 USA. NR 10 TC 3 Z9 4 U1 0 U2 1 PU AMER ENTOMOL SOC PI PHILADELPHIA PA 1900 BENJ FRANKLIN PARKWAY, PHILADELPHIA, PA 19103-1195 USA SN 0013-872X J9 ENTOMOL NEWS JI Entomol. News PD SEP-OCT PY 2000 VL 111 IS 4 BP 238 EP 242 PG 5 WC Entomology SC Entomology GA 421YR UT WOS:000168091600002 ER PT J AU Eberhard, WG AF Eberhard, WG TI Breaking the mold: behavioral variation and evolutionary innovation in Wendilgarda spiders (Araneae Theridiosomatidae) SO ETHOLOGY ECOLOGY & EVOLUTION LA English DT Review DE behavioral imprecision; orb webs; spiders; evolution ID BUILDING BEHAVIOR; ORB-WEB; CONSTRUCTION; ULOBORIDAE; PHYLOGENY AB The hypothesis that the evolutionary origin of novel behavior patterns may be imprecision in the execution of existing patterns is examined using data from spider web construction behavior. Several aspects of orb construction behavior are both extremely invariable intraspecifically, and highly conserved evolutionarily. The behavior of spiders in the genus Wendilgarda, which build highly modified, simplified webs derived from orbs, is exceptional in being highly variable both within and between species. Reduced intensity of selection for behavioral stereotypy combined with behavioral imprecision may explain the high intraspecific and intra-individual variability in Wendilgarda. This increased variation may in turn explain the unusual interspecific diversity of web designs in this genus. C1 Smithsonian Trop Res Inst, Ciudad Univ, Costa Rica. Univ Costa Rica, Escuela Biol, Ciudad Univ, Costa Rica. RP Eberhard, WG (reprint author), Smithsonian Trop Res Inst, Ciudad Univ, Costa Rica. NR 80 TC 14 Z9 17 U1 0 U2 3 PU UNIVERSITA DEGLI STUDI DI FIRENZE PI FLORENCE PA C/O PROF F DESSI-FULGHERI, VIA ROMANA 17, 50125 FLORENCE, ITALY SN 0394-9370 J9 ETHOL ECOL EVOL JI Ethol. Ecol. Evol. PD SEP PY 2000 VL 12 IS 3 BP 223 EP 235 PG 13 WC Behavioral Sciences; Zoology SC Behavioral Sciences; Zoology GA 354EQ UT WOS:000089317200001 ER PT J AU Lee, JE Furth, DG AF Lee, JE Furth, DG TI Larval morphology and biology of a North American and an Israeli Altica species (Coleoptera : Chrysomelidae : Alticinae) SO FLORIDA ENTOMOLOGIST LA English DT Article DE Altica; larvae; Florida; Israel; Rubus; Oenothera AB The mature larvae of Altica bicarinata (Kutschera) and A. marevagans Horn, collected in Israel and North America, respectively, are described and illustrated in detail for the first time. Some remarks on their taxonomy and biology are also given along with some discussion of the state of knowledge of alticine larvae. C1 Andong Natl Univ, Coll Nat Sci, Dept Biol, Andong 760749, Kyungbuk, South Korea. Smithsonian Inst, Natl Museum Nat Hist, Dept Entomol, Washington, DC 20560 USA. RP Lee, JE (reprint author), Andong Natl Univ, Coll Nat Sci, Dept Biol, Andong 760749, Kyungbuk, South Korea. NR 49 TC 8 Z9 8 U1 2 U2 2 PU FLORIDA ENTOMOLOGICAL SOC PI LUTZ PA 16125 E LAKE BURRELL DR, LUTZ, FL 33548 USA SN 0015-4040 J9 FLA ENTOMOL JI Fla. Entomol. PD SEP PY 2000 VL 83 IS 3 BP 276 EP 284 DI 10.2307/3496346 PG 9 WC Entomology SC Entomology GA 358AM UT WOS:000089535100007 ER PT J AU Dickinson, MB Whigham, DF Hermann, SM AF Dickinson, MB Whigham, DF Hermann, SM TI Tree regeneration in felling and natural treefall disturbances in a semideciduous tropical forest in Mexico SO FOREST ECOLOGY AND MANAGEMENT LA English DT Article DE disturbance; treefall gap; felling gap; selective logging; tree regeneration; root sprout; Mexico; yucatan ID MAHOGANY SWIETENIA-MACROPHYLLA; RAIN-FOREST; REDUCED-IMPACT; BURIED SEEDS; GROWTH; GAPS; SURVIVAL; MALAYSIA; AMAZON; RECRUITMENT AB Tree regeneration was compared among closed-canopy sites and 4-11-year old natural and felling gaps in a selectively logged semideciduous tropical forest in southeastern Mexico. Closed-canopy sites and gaps were selected stratified randomly. In addition, all large natural and felling gaps encountered were sampled. All stems less than or equal to 5 cm dbh were sampled in sets of 10 m(2) plots in closed-canopy sites and gaps. The origins of the 10 tallest stems in each gap were also determined. Rubber-tired skidder disturbance in felling gaps resulted in a fourfold increase in the relative abundances of a set of shade-intolerant species. The logging process also promoted root sprouting, primarily among shade-intolerant species, but also in several shade-tolerant species. Advance growth accounted for a higher proportion of tall stems in natural than felling gaps and most of these stems were of shade-tolerant species. The proportion of tall stems that originated from seeds or small seedlings at the time of gap formation was higher in felling than natural gaps and increased with canopy openness only in felling gaps. These stems were primarily from shade-intolerant species. A lack of response to canopy openness in natural gaps was likely a result of relatively low levels of understory and substrate disturbance coupled with the absence of large natural gaps with high canopy openness. The maintenance of shade-intolerant and tolerant timber species in this forest would appear to require, at minimum, the creation of large gaps with understory and substrate disturbance within a matrix of forest logged by single-tree selection methods in which understory damage was minimized. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Florida State Univ, Dept Biol Sci, Tallahassee, FL 32306 USA. Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. Tall Timbers Res Stn, Tallahassee, FL 32312 USA. RP Dickinson, MB (reprint author), Univ Calgary, Dept Biol Sci, Kananaskis Field Stn, 2500 Univ Dr 1 NW, Calgary, AB T2N 1N4, Canada. EM mdickins@ucalgary.ca OI Dickinson, Matthew/0000-0003-3635-1219; Whigham, Dennis/0000-0003-1488-820X NR 74 TC 59 Z9 65 U1 0 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1127 J9 FOREST ECOL MANAG JI For. Ecol. Manage. PD SEP 1 PY 2000 VL 134 IS 1-3 BP 137 EP 151 DI 10.1016/S0378-1127(99)00252-2 PG 15 WC Forestry SC Forestry GA 347LJ UT WOS:000088930800012 ER PT J AU Buckley, L Kearney, M de Queiroz, K AF Buckley, L Kearney, M de Queiroz, K TI Slowly-evolving protein loci and higher-level snake phylogeny: A reanalysis SO HERPETOLOGICA LA English DT Article DE allozymes; genetic distances; minimum evolution; parsimony; phenetic clustering; phylogeny; serpentes AB We reanalyzed data from a recently published study of higher-level snake relationships based on four slowly-evolving protein loci. The original study used phenetic clustering of genetic similarities and presented a single, highly resolved tree. Our reanalyses of these data reveal that the single published phenogram is only one of at least 10,000 equivalent UPGMA phenograms, the consensus of which is largely unresolved. Additive distance analysis and character-based parsimony analysis of the data also yield little resolution, indicating that these data are highly ambiguous regarding higher-level snake phylogeny. The high degree of resolution in the published phenogram is an analytical artifact resulting from the failure to consider alternative trees implied by tied distance values, which are numerous in the distance matrix derived from this particular data set. Although the published phenogram exhibits general agreement with traditional hypotheses about snake relationships, the same appears to be true for the thousands of equivalent phenograms, discrepancies among which sum to a substantial loss of resolution. Although the four loci sampled are evolving slowly relative to other commonly surveyed protein loci, they are nevertheless evolving too rapidly to be informative about the higher level phylogeny of snakes. C1 Rochester Inst Technol, Dept Biol, Rochester, NY 14623 USA. George Washington Univ, Dept Biol Sci, Washington, DC 20052 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Vertebrate Zool, Washington, DC 20560 USA. RP Buckley, L (reprint author), Rochester Inst Technol, Dept Biol, Rochester, NY 14623 USA. NR 13 TC 3 Z9 3 U1 0 U2 1 PU HERPETOLOGISTS LEAGUE PI EMPORIA PA EMPORIA STATE UNIV, DIVISION BIOLOGICAL SCIENCES, 1200 COMMERCIAL ST, EMPORIA, KS 66801-5087 USA SN 0018-0831 J9 HERPETOLOGICA JI Herpetologica PD SEP PY 2000 VL 56 IS 3 BP 324 EP 332 PG 9 WC Zoology SC Zoology GA 359NA UT WOS:000089615900005 ER PT J AU Gladman, B Kavelaars, JJ Holman, M Petit, JM Scholl, H Nicholson, P Burns, JA AF Gladman, B Kavelaars, JJ Holman, M Petit, JM Scholl, H Nicholson, P Burns, JA TI The discovery of Uranus XIX, XX, and XXI SO ICARUS LA English DT Article DE satellites; Uranus; Neptune ID SATELLITES; ORBITS AB Motivated by the discovery of the first two irregular satellites of Uranus in 1997, our team has conducted a search covering approximately 90% of the dynamically stable region around Uranus, We have discovered three additional objects moving at rates consistent with satellite orbital motion, At the end of 1999, the available observations are of sufficient quality to almost guarantee that these three new objects are bound to the planet and confirm that Uranus is host to a system of numerous, but faint and small, irregular satellites. We report a preliminary negative result in a similar search near Neptune, (C) 2000 Academic Press. C1 Observ Cote Azur, F-06304 Nice 4, France. McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Cornell Univ, Ithaca, NY 14853 USA. RP Gladman, B (reprint author), Observ Cote Azur, BP4229, F-06304 Nice 4, France. NR 14 TC 39 Z9 39 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD SEP PY 2000 VL 147 IS 1 BP 320 EP 324 DI 10.1006/icar.2000.6463 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 349WG UT WOS:000089068100025 ER PT J AU Gingerich, O AF Gingerich, O TI Kepler's tubingen: Stimulus to a theological mathematics. SO ISIS LA English DT Book Review C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0021-1753 J9 ISIS JI Isis PD SEP PY 2000 VL 91 IS 3 BP 587 EP 588 DI 10.1086/384883 PG 2 WC History & Philosophy Of Science SC History & Philosophy of Science GA 375EH UT WOS:000165386200039 ER PT J AU Davis, AB AF Davis, AB TI Manifesting medicine: Bodies and machines. SO ISIS LA English DT Book Review C1 Smithsonian Inst, Natl Museum Amer Hist, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0021-1753 J9 ISIS JI Isis PD SEP PY 2000 VL 91 IS 3 BP 614 EP 615 DI 10.1086/384911 PG 2 WC History & Philosophy Of Science SC History & Philosophy of Science GA 375EH UT WOS:000165386200067 ER PT J AU Hacker, BC AF Hacker, BC TI Fast tanks and heavy bombers: Innovation in the U.S army, 1917-1945. SO ISIS LA English DT Book Review C1 Smithsonian Inst, Natl Museum Amer Hist, Armed Forces Hist Collect, Washington, DC 20560 USA. RP Hacker, BC (reprint author), Smithsonian Inst, Natl Museum Amer Hist, Armed Forces Hist Collect, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0021-1753 J9 ISIS JI Isis PD SEP PY 2000 VL 91 IS 3 BP 630 EP 631 DI 10.1086/384929 PG 2 WC History & Philosophy Of Science SC History & Philosophy of Science GA 375EH UT WOS:000165386200085 ER PT J AU Karovska, M Wood, B Chen, J Cook, J Howard, R AF Karovska, M Wood, B Chen, J Cook, J Howard, R TI Exploring coronal structures with SOHO SO JOURNAL OF ASTROPHYSICS AND ASTRONOMY LA English DT Article; Proceedings Paper CT IAU Colloquium on Cyclical Evolution of Solar Magnetic Fields CY DEC 13-16, 1999 CL KODAIKANAL OBSERV, KODAIKANAL, INDIA SP Int Astron Union HO KODAIKANAL OBSERV DE Corona; CME ID MAGNETIC-FLUX ROPE; LASCO; EIT AB We applied advanced image enhancement techniques to explore in detail the characteristics of the small-scale structures and/or the low contrast structures in several Coronal Mass Ejections (CMEs) observed by SOHO. We highlight here the results from our studies of the morphology and dynamical evolution of CME structures in the solar corona using two instruments on board SOHO: LASCO and EIT. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. USN, Res Lab, Washington, DC 20375 USA. RP Karovska, M (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU INDIAN ACADEMY SCIENCES PI BANGALORE PA P B 8005 C V RAMAN AVENUE, BANGALORE 560 080, INDIA SN 0250-6335 J9 J ASTROPHYS ASTRON JI J. Astrophys. Astron. PD SEP-DEC PY 2000 VL 21 IS 3-4 BP 403 EP 406 DI 10.1007/BF02702433 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 403FV UT WOS:000167032600061 ER PT J AU Winker, K Graves, GR Braun, MJ AF Winker, K Graves, GR Braun, MJ TI Genetic differentiation among populations of a migratory songbird: Limnothlypis swainsonii SO JOURNAL OF AVIAN BIOLOGY LA English DT Article ID NORTH-AMERICAN CHICKADEES; CONTROL-REGION SEQUENCES; GEOGRAPHIC-VARIATION; NATURAL-POPULATIONS; CARDUELIS-CHLORIS; GLACIAL TIMES; RARE ALLELES; F-STATISTICS; FLOW; DIVERGENCE AB Population structure and gene how were inferred from isozyme variation at 26 loci among five populations of Limnothlypis swainsonii (Swainson's Warbler; Parulidae), a Nearctic-Neotropic migrant songbird breeding in the unglaciated southeastern U.S.A. These populations exhibit relatively high levels of heterozygosity ((H) over bar(o) = 0.083), and 16 of 26 loci were polymorphic in at least one population ((P) over bar = 0.385). Allelic frequencies were significantly heterogeneous at five loci, indicating a surprising degree of population structure for a migratory bird with no recognized subspecies (F-ST = 0.043). Moderate levels of gene flow are inferred (Nm = 1.5 to 11.7), yet population structure does not fit an isolation-by-distance model. Genetic heterogeneity is mostly due to differentiation between an Arkansas population and four populations from the coastal plain (from Louisiana to Virginia). Genetic drift may be responsible for much of the observed structure, but the lack of obvious barriers to dispersal between Arkansas and the coastal plain suggests that differentiation has been maintained by some other mechanism(s). Vicariance events on the breeding range, a split wintering range, or both could contribute to the pattern of differentiation observed. C1 Natl Museum Nat Hist, Dept Vertebrate Zool, Washington, DC 20560 USA. Smithsonian Inst, Lab Mol Systemat, Washington, DC 20560 USA. RP Winker, K (reprint author), Univ Alaska Museum, 907 Yukon Dr, Fairbanks, AK 99775 USA. RI Winker, Kevin/M-2042-2014 OI Winker, Kevin/0000-0002-8985-8104 NR 89 TC 15 Z9 16 U1 1 U2 4 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0908-8857 J9 J AVIAN BIOL JI J. Avian Biol. PD SEP PY 2000 VL 31 IS 3 BP 319 EP 328 DI 10.1034/j.1600-048X.2000.310307.x PG 10 WC Ornithology SC Zoology GA 362ND UT WOS:000089783300007 ER PT J AU Stanley, DJ Chen, ZY AF Stanley, DJ Chen, ZY TI Radiocarbon dates in China's Holocene Yangtze delta: Record of sediment storage and reworking, not timing of deposition SO JOURNAL OF COASTAL RESEARCH LA English DT Article DE alluvial deposits; climate change; coastal protection; cores; delta plain; deposition; erosion; Holocene; Pleistocene; sediment reworking; storage; subsidence ID SEA-LEVEL RISE; AMAZON RIVER; SUBSIDENCE; BRAZIL; PEATS AB Evaluation of conventional and AMS radiocarbon dates, obtained for 65 Holocene sediment samples in 20 cores collected in the Yangtze delta, China, indicates that only about one in 4 dates falls within an expected time range. In this Holocene deltaic system, most radiocarbon-dated samples do not become progressively younger upcore, and there is no direct relationship between age and depth. About one in 6 dates is too young, recording locally truncated stratigraphic sections. Of particular note are the nearly two-thirds of all radiocarbon dates that record ages that are much too old, by 1000 to 10,000 years (23% are of Pleistocene age). This phenomenon results from the introduction of old carbon during sediment storage and reworking along the dispersal path between headlands and the coast. Thus, rather than recording final time of Holocene deposition at deltaic core sites, dates in Yangtze delta sediment appear to indicate a time lapse that occurred during storage and transport cycles in the fluvial valley and delta plain. There is no simple, obvious or universal solution to this radiocarbon-dating problem in deltaic sequences. The problem warrants attention since reliable dating of Holocene sequences is essential for measurement of rates of sediment accumulation and delta margin subsidence relative to sea level, two of the parameters needed to help implement protection measures along the vulnerable low-lying Yangtze delta coast. At present, a multi-method dating approach (amino acid racemization, isotopic analyses, archaeological determination, and others) would constrain sediment age, and provide a more reliable measure of deposition time in such settings than by radiocarbon dating alone. C1 Smithsonian Inst, Deltas Global Change Program, Washington, DC 20560 USA. E China Normal Univ, Dept Geog, Remote Sensing Lab, Shanghai 200062, Peoples R China. RP Stanley, DJ (reprint author), Smithsonian Inst, Deltas Global Change Program, E-206 NMNH Paleobiol, Washington, DC 20560 USA. NR 40 TC 24 Z9 29 U1 1 U2 2 PU COASTAL EDUCATION & RESEARCH FOUNDATION PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 USA SN 0749-0208 J9 J COASTAL RES JI J. Coast. Res. PD FAL PY 2000 VL 16 IS 4 BP 1126 EP 1132 PG 7 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA 384GY UT WOS:000165935500015 ER PT J AU Stanley, DJ AF Stanley, DJ TI Radiocarbon dating the artificially contained surfaces of the Rhone deltaic plain, southern France SO JOURNAL OF COASTAL RESEARCH LA English DT Article DE AMS dating; cores; dikes; floods; Holocene deltas; impounded surfaces; old carbon; overbank deposition; remobilization; sea-level rise; sediment storage; subsidence ID SEA-LEVEL RISE; SEDIMENTS; RIVER; AREA AB Surficial sediment surfaces of various world deltaic plains are commonly rabiorarbon dated to over 2000 year before present (BP), rather than to a modern age. In the present investigation of the Rhone plain, southern France, surficial sediments that record anomalously old dates (to >4000 BP) occur preferentially on flooded surfaces where old carbon has accumulated. This old carbon is a component of recently eroded, fluvially-derived sediment that has been redeposited farther downvalley. In contrast, most radiocarbon-dated samples (plant and organic carbon) from artificially contained surfaces on the Rhone plain are of modern age. Modern radiocarbon dates prevail at artificially diked localities where (1) soil layers form on plain surfaces that are not periodically buried by flood deposits, and (2) accretion rates of recently deposited sediment incorporating reworked old carbon are minimal. Modern radiocarbon dates obtained at the Rhone deltaic plain provide chronostratigraphic markers against which Holocene dates from subsurface strata can be compared and spurious dates eliminated. The presence of such dates at many sites also provides a means with which to measure recent movement of land surfaces relative to sea level. Reliable dating of surficial sediment on artificially contained surfaces is one of the critical measures needed to help plan realistic protection for lower-lying sectors of the Rhone delta in danger of inundation. C1 Smithsonian Inst, Deltas Global Change Program, Washington, DC 20560 USA. RP Stanley, DJ (reprint author), Smithsonian Inst, Deltas Global Change Program, E206-NMNH, Washington, DC 20560 USA. NR 32 TC 8 Z9 8 U1 0 U2 1 PU COASTAL EDUCATION & RESEARCH FOUNDATION PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 USA SN 0749-0208 J9 J COASTAL RES JI J. Coast. Res. PD FAL PY 2000 VL 16 IS 4 BP 1157 EP 1161 PG 5 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA 384GY UT WOS:000165935500019 ER PT J AU Yih, W Coats, DW AF Yih, W Coats, DW TI Infection of Gymnodinium sanguineum by the dinoflagellate Amoebophrya sp.: Effect of nutrient environment on parasite generation time, reproduction, and infectivity SO JOURNAL OF EUKARYOTIC MICROBIOLOGY LA English DT Article DE algal blooms; infection level; parasitism; phytoplankton ID HETEROSIGMA-AKASHIWO RAPHIDOPHYCEAE; RED-TIDE; POPULATION-DYNAMICS; DIATOM ASTERIONELLA; VIRAL MORTALITY; CHESAPEAKE BAY; ALGAL BLOOMS; LIFE-CYCLE; GROWTH; PHYTOPLANKTON AB Preliminary attempts to culture Amoebophyra sp., a parasite of Gymnodinium sanguineum from Chesapeake Bay, indicated that success may be influenced by water quality. To explore that possibility, we determined development time, reproductive output. and infectivity of progeny (i.e. dinospores) for Amoebophyra sp. maintained on G. sanguineum grown in four different culture media. The duration of the parasite's intracellular growth phase showed no significant difference among treatments: however, the time required for completion of multiple parasite generations did, with elapsed time to the middle of the third generation being shorter in nutrient-replete media. Parasites of hosts grown in nutrient-replete medium also produced three to four times more dinospores than those infecting hosts under low-nutrient conditions, with mean values of 380 and 130 dinospores/host, respectively. Dinospore production relative to host biovolume also differed, with peak values of 7.4 per 1,000 mu m(3) host for nutrient-replete medium and 3.8 per 1,000 mu m(3) host for nutrient-limited medium. Furthermore, dinospores produced by "high-nutrient" parasites had a higher success rate than those formed by "low-nutrient" parasites. Results suggest that Amoebophyra sp. is well adapted to exploit G. sanguineum populations in nutrient-enriched environments. C1 Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. Kunsan Natl Univ, Dept Oceanog, Kunsan 573701, South Korea. RP Coats, DW (reprint author), Smithsonian Environm Res Ctr, POB 28, Edgewater, MD 21037 USA. EM coats@serc.si.edu NR 50 TC 28 Z9 31 U1 2 U2 9 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1066-5234 EI 1550-7408 J9 J EUKARYOT MICROBIOL JI J. Eukaryot. Microbiol. PD SEP-OCT PY 2000 VL 47 IS 5 BP 504 EP 510 DI 10.1111/j.1550-7408.2000.tb00082.x PG 7 WC Microbiology SC Microbiology GA 354ZL UT WOS:000089361100011 PM 11001148 ER PT J AU Goldsworthy, S Francis, J Boness, D Fleischer, R AF Goldsworthy, S Francis, J Boness, D Fleischer, R TI Variation in the mitochondrial control region in the Juan Fernandez fur seal (Arctocephalus philippii) SO JOURNAL OF HEREDITY LA English DT Article ID POPULATION BOTTLENECKS; GENETIC-VARIABILITY; DNA; GAZELLA; ISLANDS; MODELS AB The Juan Fernandez fur seal (Arctocephalus philippii) was allegedly extremely abundant, numbering as many as 4 million prior to sealing which continued from the late 17th to the late 19th century. By the end of the sealing era the species was thought to be extinct until they were rediscovered at Alejandro Selkirk Island in 1965, Historic records would suggest that the species underwent a substantial population bottleneck as a result of commercial sealing, and from population genetic theory we predicted that the genetic variability in the species would be low. We compared the mtDNA control region sequence from 28 Juan Fernandez fur seals from two islands in the Juan Fernandez Archipelago (Chile). Contrary to expectation, we found that variation in the Juan Fernandez fur seals is not greatly reduced in comparison to other pinniped taxa, especially given the apparent severity of the bottleneck they underwent, We also determined minor, but significantly different haplotype frequencies among the populations on the two islands (Alejandro Selkirk and Robinson Crusoe Islands), but no difference in their levels of variability. Such differences may have arisen stochastically via a recent founder event from Alejandro Selkirk to Robinson Crusoe Island or subsequent genetic drift. C1 Smithsonian Inst, Natl Zool Pk, Washington, DC 20008 USA. RP Fleischer, R (reprint author), La Trobe Univ, Dept Zool, Bundoora, Vic 3083, Australia. NR 42 TC 18 Z9 18 U1 3 U2 11 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 0022-1503 J9 J HERED JI J. Hered. PD SEP-OCT PY 2000 VL 91 IS 5 BP 371 EP 377 DI 10.1093/jhered/91.5.371 PG 7 WC Evolutionary Biology; Genetics & Heredity SC Evolutionary Biology; Genetics & Heredity GA 350YQ UT WOS:000089129600004 PM 10994703 ER PT J AU McCarthy, MC Levine, ES Apponi, AJ Thaddeus, P AF McCarthy, MC Levine, ES Apponi, AJ Thaddeus, P TI Experimental structures of the carbon chains HC7N, HC9N, and HC11N by isotopic substitution SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID COUPLED-CLUSTER CALCULATIONS; C=C-C=C-C=N; LABORATORY DETECTION; MICROWAVE-SPECTRUM; DIPOLE-MOMENT; MOLECULES; PREDICTIONS AB The effective structures (r(o)) of the three linear cyanopolyynes HC7N, HC9N, and HC11N have been determined to high accuracy by isotopic substitution, following detection in a supersonic molecular beam with a Fourier transform microwave spectrometer of all of the singly substituted rare isotopic species. For each chain, the lengths of the individual bonds have been determined to an accuracy of 0.001 Angstrom. or 0.1% toward the end of the chain and to 0.01 Angstrom or 1.0% toward the center. The experimental structures are in excellent agreement with recent high-level theoretical calculations, or, in the case of HC11N, with extrapolation from HC9N, The three polyynes studied here represent the largest reactive carbon chain molecules for which accurate structures have been derived empirically. For HC7N and HC9N, it has been possible to resolve at high-resolution nitrogen hyperfine structure in the lower rotational transitions and determine eQq for all of the singly substituted isotopic species of HC7N and for normal HC9N. (C) 2000 Academic Press. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. RP McCarthy, MC (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI McCarthy, Michael/0000-0001-9142-0008 NR 17 TC 23 Z9 23 U1 0 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD SEP PY 2000 VL 203 IS 1 BP 75 EP 81 DI 10.1006/jmsp.2000.8149 PG 7 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 347WM UT WOS:000088952200009 ER PT J AU Plasman, V Braekman, JC Daloze, D Windsor, D Pasteels, JM AF Plasman, V Braekman, JC Daloze, D Windsor, D Pasteels, JM TI Triterpene saponins, quaternary ammonium compounds, phosphatidyl cholines, and amino acids in the pronotal and elytral secretions of Platyphora opima and Desmogramma subtropica SO JOURNAL OF NATURAL PRODUCTS LA English DT Article ID DEFENSE; BEETLES AB Secretions of the pronotal and elytral glands;of adults of the chrysomelid beetle Platyphora opima from Panama have been shown to contain two oleanane triterpene saponins: the known 3-O-beta-D-glucopyranosyl-(1-->3)-beta-D-glucuronopyranosyl-oleanolic acid-28-O-beta-D-glucopyranoside and compound 1, whose structure was established as 3-O-beta-D-glucopyranosyl-(1-->3)-beta-D-glucuronopyranosyl-29-hydroxyoleanolic acid-28-O-beta-D-glucopyranoside by a combination of 1D and 2D NMR methods (COSY, HMQC, HMBC, and TOCSY) and FABMS. The secretions also contained N,N,N-trimethylcadaverine and its 1,2-dehydro derivative 3, as well as the nicotinamide derivative 4. Secretions of Desmogramma subtropica, also from Panama, contained a!; sole triterpene derivative 3-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucur oleanolic acid (2), together with glutamic acid, glutamine, pyroglutamic acid, and arginine. A mixture of phosphatidylcholines was also present in the secretions of both species. C1 Free Univ Brussels, Dept Organ Chem, Bioorgan Chem Lab, B-1050 Brussels, Belgium. Free Univ Brussels, Lab Cellular & Anim Biol, B-1050 Brussels, Belgium. Smithsonian Trop Res Inst, Balboa, Panama. RP Braekman, JC (reprint author), Free Univ Brussels, Dept Organ Chem, Bioorgan Chem Lab, CP 160-07,Ave FD Rosevelt 50, B-1050 Brussels, Belgium. NR 13 TC 17 Z9 17 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0163-3864 J9 J NAT PROD JI J. Nat. Prod. PD SEP PY 2000 VL 63 IS 9 BP 1261 EP 1264 DI 10.1021/np9906370 PG 4 WC Plant Sciences; Chemistry, Medicinal; Pharmacology & Pharmacy SC Plant Sciences; Pharmacology & Pharmacy GA 358CR UT WOS:000089540100018 PM 11000032 ER PT J AU Sanchez-Villagra, MR Burnham, RJ Campbell, DC Feldmann, RM Gaffney, ES Kay, RF Lozsan, R Purdy, R Thewissen, JGM AF Sanchez-Villagra, MR Burnham, RJ Campbell, DC Feldmann, RM Gaffney, ES Kay, RF Lozsan, R Purdy, R Thewissen, JGM TI A new near-shore marine fauna and flora from the early neogene of northwestern Venezuela SO JOURNAL OF PALEONTOLOGY LA English DT Article ID EXTINCTION; VENERIDAE; AMERICA AB A diverse near-shore marine fauna existed during the early Miocene in what is today an arid inland region about 90 km south of the Caribbean coast of northern Venezuela, a poorly known area geologically and paleontologically. The fossil locality consists of more than 100 m of section exposed in an area of about 1 km(2). We report the discovery of 20 molluscan species, one crab (Portunus oblongus), at least three shades (Hemipristis serra and Carcharhinus spp.), one turtle ("Podocnemis" venezuelensis), one crocodile (Crocodylidae), two whales (Odontoceti) and a three dimensional cast of the mesocarp or endocarp of a palm fruit. Several taxa are reported for the first time in Venezuela or in northern South America. The fauna indicates, or at least is consistent with, an early Miocene age for the locality, and a near-shore and shallow water marine depositional environment. We suggest that the earliest mammal previously reported from Venezuela, the pyrothere Proticia venezuelensis, was collected in Miocene rocks of the Castillo Formation instead of Eocene rocks of the Trujillo Formation. C1 Univ Tubingen, D-72076 Tubingen, Germany. Univ Michigan, Museum Paleontol, Ann Arbor, MI 48109 USA. Univ N Carolina, Dept Geol Sci, Chapel Hill, NC 27599 USA. Kent State Univ, Dept Geol, Kent, OH 44242 USA. Amer Museum Nat Hist, Dept Vertebrate Paleontol, New York, NY 10024 USA. Duke Univ, Med Ctr, Dept Biol Anthropol & Anat, Durham, NC 27710 USA. Ctr Excursionismo Cient Estado Lara, Barquisimeto, Venezuela. Smithsonian Inst, Natl Museum Amer Hist, Dept Paleobiol, Washington, DC 20560 USA. Northeastern Ohio Univ Coll Med & Pharm Anat, Rootstown, OH 44272 USA. RP Sanchez-Villagra, MR (reprint author), Univ Tubingen, Morgenstelle 28, D-72076 Tubingen, Germany. EM marcelo.sanchez@uni-tuebingen.de OI Thewissen, J. G. M./0000-0002-0973-4137 NR 98 TC 36 Z9 39 U1 0 U2 3 PU PALEONTOLOGICAL SOC INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 USA SN 0022-3360 J9 J PALEONTOL JI J. Paleontol. PD SEP PY 2000 VL 74 IS 5 BP 957 EP 968 DI 10.1666/0022-3360(2000)074<0957:ANNSMF>2.0.CO;2 PG 12 WC Paleontology SC Paleontology GA 356CN UT WOS:000089426900014 ER PT J AU Goldman, A Gamache, RR Perrin, A Flaud, JM Rinsland, CP Rothman, LS AF Goldman, A Gamache, RR Perrin, A Flaud, JM Rinsland, CP Rothman, LS TI HITRAN partition functions and weighted transition-moments squared SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Review ID FAR-INFRARED-SPECTRUM; FOURIER-TRANSFORM SPECTROSCOPY; HIGH-RESOLUTION SPECTROSCOPY; SUBMILLIMETER-WAVE SPECTRUM; ABSOLUTE LINE-INTENSITIES; CHLORINE NITRATE; GROUND-STATE; ROTATIONAL SPECTRUM; TORSIONAL SPECTRUM; NU-3 BANDS AB The calculations of the partition functions and weighted transition-moments squared in the HITRAN database are reviewed. It was found that for several of the HITRAN molecules corrections are needed to the partition functions. Corrections to the weighted transition-moments squared are needed for most of the HITRAN molecules. Replacement of the weighted transition-moments squared by other quantities is proposed. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Denver, Dept Phys, Denver, CO 80208 USA. Univ Massachusetts, Dept Environm Earth & Atmospher Sci, Lowell, MA 01854 USA. Univ Paris Sud, Photophys Mol Lab, F-91405 Orsay, France. NASA, Div Atmospher Sci, Langley Res Ctr, Hampton, VA 23681 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Goldman, A (reprint author), Univ Denver, Dept Phys, Denver, CO 80208 USA. OI Rothman, Laurence/0000-0002-3837-4847 NR 111 TC 41 Z9 42 U1 2 U2 16 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD SEP 1 PY 2000 VL 66 IS 5 BP 455 EP 486 DI 10.1016/S0022-4073(99)00176-4 PG 32 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 318KD UT WOS:000087282300003 ER PT J AU Reinert, JF AF Reinert, JF TI New classification for the composite genus Aedes (Diptera : Culicidae : Aedini), elevation of subgenus Ochlerotatus to generic rank, reclassification of the other subgenera, and notes on certain subgenera and species SO JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION LA English DT Article DE Aedes; Ochlerotatus; Aedini; Armigerini; taxonomy AB The composite genus Aedes is divided into 2 genera, Aedes and Ochlerotatus, on the basis of consistent primary characters of the female and male genitalia. Ochleroratus is separated into 2 sections. Additional supplemental features of the female and male genitalia, 4th-stage larvae, and pupae are provided for the separation of the genera and sections as well as a discussion of exceptions and comparisons. This classification is based on a morphological examination of specimens of over 65% of the currently recognized species and all subgenera previously included in Aedes and representative material of all subgenera and genera of tribe Aedini. Published literature was examined and evaluated. All currently recognized subgenera are assigned to the appropriate genus. The proposed new generic classification provides better defined genera and a more natural arrangement of included taxa. Armigerini is formally recognized as a synonym, in part, of Aedini. C1 USDA ARS, Ctr Med Agr & Vet Entomol, Gainesville, FL 32608 USA. Smithsonian Inst, Natl Museum Nat Hist, Walter Reed Biosystemat Unit, Washington, DC 20560 USA. RP Reinert, JF (reprint author), USDA ARS, Ctr Med Agr & Vet Entomol, 1600-1700 SW 23rd Dr, Gainesville, FL 32608 USA. NR 69 TC 206 Z9 243 U1 3 U2 7 PU AMER MOSQUITO CONTROL ASSOC PI MOUNT LAUREL PA 15000 COMMERCE PARKWAY, SUITE C, MOUNT LAUREL, NJ 08054 USA SN 8756-971X EI 1943-6270 J9 J AM MOSQUITO CONTR JI J. Am. Mosq. Control Assoc. PD SEP PY 2000 VL 16 IS 3 BP 175 EP 188 PG 14 WC Entomology SC Entomology GA 371GM UT WOS:000165170500001 PM 11081644 ER PT J AU Pecor, JE Jones, J Turell, MJ Fernandez, R Carbajal, F O'Guinn, M Sardalis, M Watts, D Zyzak, M Calampa, C Klein, TA AF Pecor, JE Jones, J Turell, MJ Fernandez, R Carbajal, F O'Guinn, M Sardalis, M Watts, D Zyzak, M Calampa, C Klein, TA TI Annotated checklist of the mosquito species encountered during arboviral studies in Iquitos, Peru (Diptera : Culicidae) SO JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION LA English DT Article DE Culicidae; mosquitoes; checklist; Peru; distribution; bionomics ID CULEX MELANOCONION DIPTERA; SPISSIPES SECTION AB A checklist of the mosquito fauna encountered during arboviral studies in Iquitos, Peru, is presented. A total of 16 genera, 30 subgenera, and 96 species were identified, including 24 species reported from Peru for the 1st time. Notations on the taxonomy and biology for 28 species are also provided. C1 Walter Reed Army Inst Res, Dept Entomol, Washington, DC 20307 USA. USA, Med Res Inst Infect Dis, Div Virol, Ft Detrick, MD 21702 USA. USN, Med Res Ctr, Detachment Lima, APO, AA 34031 USA. RP Pecor, JE (reprint author), Smithsonian Inst, Walter Reed Biosystemat Unit, Museum Support Ctr, Washington, DC 20560 USA. NR 38 TC 27 Z9 27 U1 0 U2 3 PU AMER MOSQUITO CONTROL ASSOC PI MOUNT LAUREL PA 15000 COMMERCE PARKWAY, SUITE C, MOUNT LAUREL, NJ 08054 USA SN 8756-971X EI 1943-6270 J9 J AM MOSQUITO CONTR JI J. Am. Mosq. Control Assoc. PD SEP PY 2000 VL 16 IS 3 BP 210 EP 218 PG 9 WC Entomology SC Entomology GA 371GM UT WOS:000165170500005 PM 11081648 ER PT J AU Case, JA Martin, JE Chaney, DS Reguero, M Marenssi, SA Santillana, SM Woodburne, MO AF Case, JA Martin, JE Chaney, DS Reguero, M Marenssi, SA Santillana, SM Woodburne, MO TI The first duck-billed dinosaur (Family Hadrosauridae) from Antarctica SO JOURNAL OF VERTEBRATE PALEONTOLOGY LA English DT Article ID CRETACEOUS STRATIGRAPHY; ISLAND C1 St Marys Coll, Dept Biol, Moraga, CA 94575 USA. S Dakota Sch Mines & Technol, Museum Geol, Rapid City, SD 57701 USA. Smithsonian Inst, Natl Air & Space Museum, Dept Paleobiol, MRC 121, Washington, DC 20560 USA. Museo La Plata, Dept Vertebrate Paleontol, RA-1900 La Plata, Argentina. Inst Antarct Argentino, RA-1010 Buenos Aires, DF, Argentina. Univ Calif Riverside, Dept Earth Sci, Riverside, CA 92521 USA. RP Case, JA (reprint author), St Marys Coll, Dept Biol, POB 4507, Moraga, CA 94575 USA. NR 29 TC 47 Z9 51 U1 0 U2 3 PU SOC VERTEBRATE PALEONTOLOGY PI NORTHBROOK PA 60 REVERE DR, STE 500, NORTHBROOK, IL 60062 USA SN 0272-4634 J9 J VERTEBR PALEONTOL JI J. Vertebr. Paleontol. PD SEP PY 2000 VL 20 IS 3 BP 612 EP 614 DI 10.1671/0272-4634(2000)020[0612:TFDBDF]2.0.CO;2 PG 3 WC Paleontology SC Paleontology GA 401TC UT WOS:000166943500020 ER PT J AU Larsen, RS Salman, MD Mikota, SK Isaza, R Montali, RJ Triantis, J AF Larsen, RS Salman, MD Mikota, SK Isaza, R Montali, RJ Triantis, J TI Evaluation of a multiple-antigen enzyme-linked immunosorbent assay for detection of Mycobacterium tuberculosis infection in captive elephants SO JOURNAL OF ZOO AND WILDLIFE MEDICINE LA English DT Article DE elephant; Mycobacterium tuberculosis; ELISA; Elephas maximus; epidemiology; Loxodonta africanu ID BOVINE TUBERCULOSIS; CERVUS-ELAPHUS; PROTEIN-A; DIAGNOSIS; ANTIBODIES; COMPLEX; REAGENT; DEER AB Mycobacterium tuberculosis has become an important agent of disease in the captive elephant population of the United States. although current detection methods appear to be inadequate for effective disease management. This investigation sought to validate a multiple-antigen enzyme-linked immunosorbent assay (ELISA) for screening of M. tuberculosis infection in captive elephants and to document the elephant's serologic response over time using a cross-sectional observational study design. Serum samples were collected from 51 Asian elephants (Elephas maximus) and 26 African elephants (Loxodonta africana) from 16 zoos and circuses throughout the United States. Infection status of each animal was determined by mycobacterial culture of trunk washes. Reactivity of each serum sample against six antigens was determined, and the linear combination of antigens that accurately predicted the infection status of the greatest number of animals was determined by discriminant analysis. The resulting classification functions were used to calculate the percentage of animals that were correctly classified (i.e,, specificity and sensitivity). Of the 77 elephants sampled, 47 fit the criteria for inclusion in discriminant analysis. Of these, seven Asian elephants were considered infected: 25 Asian elephants and 15 African elephants were considered noninfected. The remaining elephants had been exposed to one or more infected animals. The specificity and sensitivity of the multiple-antigen ELISA were both 100% (91.9-100% and 53.3-100%. respectively) with 95% confidence intervals. Mycobacterium bovis culture filtrate showed the highest individual antigen specificity (95%: 83.0-100%) and sensitivity (100%; 54.4-100%). Serum samples from 34 elephants were analyzed over time by the response to the culture filtrate antigen: four of these elephants were culture positive and had been used to calculate the discriminant function. Limitations such as sample size. compromised ability to ascertain each animal's true infection status, and absence of known-infected African elephants suggest that much additional research needs to be conducted regarding the use of this ELISA. However, the results indicate that this multiple-antigen ELISA would be a valuable screening test for detecting M. tuberculosis infection in elephant herds. C1 Colorado State Univ, Coll Vet Med & Biomed Sci, Ctr Vet Epidemiol & Anim Dis Surveillance Syst, Ft Collins, CO 80523 USA. Audubon Ctr Res Endangered Species, New Orleans, LA 70131 USA. Kansas State Univ, Coll Vet Med, Dept Clin Sci, Manhattan, KS 66506 USA. Smithsonian Inst, Natl Zool Pk, Dept Pathol, Washington, DC 20008 USA. RP Larsen, RS (reprint author), N Carolina State Univ, Coll Vet Med, Dept Clin Sci, 4700 Hillsborough St, Raleigh, NC 27606 USA. NR 35 TC 16 Z9 16 U1 0 U2 8 PU AMER ASSOC ZOO VETERINARIANS PI MEDIA PA 6 NORTH PENNELL ROAD, MEDIA, PA 19063 USA SN 1042-7260 J9 J ZOO WILDLIFE MED JI J. Zoo Wildl. Med. PD SEP PY 2000 VL 31 IS 3 BP 291 EP 302 PG 12 WC Veterinary Sciences SC Veterinary Sciences GA 402WU UT WOS:000167011800002 PM 11237135 ER PT J AU Reents-Budet, D AF Reents-Budet, D TI The art of the Maya scribe. SO LANGUAGE IN SOCIETY LA English DT Book Review C1 Smithsonian Ctr Mat Res & Educ, Durham, NC 27707 USA. RP Reents-Budet, D (reprint author), Smithsonian Ctr Mat Res & Educ, 2211 Meade Lane, Durham, NC 27707 USA. NR 18 TC 0 Z9 0 U1 0 U2 1 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0047-4045 J9 LANG SOC JI Lang. Soc. PD SEP PY 2000 VL 29 IS 3 BP 464 EP 467 DI 10.1017/S004740450038304X PG 4 WC Linguistics; Sociology SC Linguistics; Sociology GA 359LU UT WOS:000089613000021 ER PT J AU Killion, TW AF Killion, TW TI A favored place: San Juan River wetlands, Central Veracruz, A.D. 500 to the present SO LATIN AMERICAN ANTIQUITY LA English DT Book Review C1 Smithsonian Inst, Washington, DC 20560 USA. RP Killion, TW (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SOC AMER ARCHAEOLOGY PI WASHINGTON PA 900 SECOND ST., NE STE 12, WASHINGTON, DC 20002-3557 USA SN 1045-6635 J9 LAT AM ANTIQ JI Lat. Am. Antiq. PD SEP PY 2000 VL 11 IS 3 BP 310 EP 311 DI 10.2307/972187 PG 2 WC Archaeology SC Archaeology GA 355EX UT WOS:000089374200014 ER PT J AU Vogel, K Gektidis, M Golubic, S Kiene, WE Radtke, G AF Vogel, K Gektidis, M Golubic, S Kiene, WE Radtke, G TI Experimental studies on microbial bioerosion at Lee Stocking Island, Bahamas and One Tree Island, Great Barrier Reef, Australia: implications for paleoecological reconstructions SO LETHAIA LA English DT Article DE Bahamas; bioerosion; ecology; endoliths; Great Barrier Reef; ichnology; paleoecology ID LAGOONS FRENCH-POLYNESIA; CORAL-REEFS; ENDOLITHS; WATER; MICROBORINGS; INFESTATION; SEDIMENTS; MOOREA; FUNGI AB Different kinds of experimental calcareous substrates were exposed at Lee Stocking Island (Bahamas) and One Tree Island (Great Barrier Reef, Australia) to study which endolithic bacteria, algae and fungi contribute to bioerosion and what their bioerosion rates are. The sites at Lee Stocking Island were several leeward shallow water and several windward shallow and deep-water positions (from the Acropora palmata reef at 2 m down to 275 m depth). At One Tree Island, the experiments were conducted in patch reefs treated with P and N to study the influence of mineral nutrients on bioerosion. The exposure periods ranged from 1 week to 2 years. The micritic carbonate substrates exposed on Lee Stocking Island contained 6 genera with 15 species of cyanobacteria, green and red algae, and different kinds of microendolithic heterotrophs. The mean values of bioerosion rates measured between 1 to 2 g/m(2)/y at 275 m and 520 g/m(2)/y at one of the leeward sites. The composition of the endolithic community and the bioerosion rates changed over time. At One Tree Island, shell pieces of Tridacna were used as substrate exposed for 5 months to endolith activity. Five genera and 6 species of cyanobacteria, green and red algae and different kinds of heterotrophic microendoliths were found with bioerosion rates of 20-30 g/m(2)/y. There are differences in abundance of taxa between Lee Stocking Island and One Tree Island. The introduction of nutrients had no apparent impact on the microborer community. Controlling factors for the distribution and abundance of microborers are mainly light, but also the kind of substrate and, possibly, the biogeographic position. The results support the paleoecological importance of microendoliths. C1 Univ Frankfurt, Inst Geol & Palaontol, D-60054 Frankfurt, Germany. Boston Univ, Ctr Biol Sci, Boston, MA 02215 USA. Smithsonian Inst, Natl Museum Nat Hist, Washington, DC 20560 USA. Hess Landesamt Umwelt & Geol, D-65203 Wiesbaden, Germany. RP Vogel, K (reprint author), Univ Frankfurt, Inst Geol & Palaontol, Senckenberganlage 32-34, D-60054 Frankfurt, Germany. NR 69 TC 94 Z9 100 U1 0 U2 12 PU TAYLOR & FRANCIS AS PI OSLO PA CORT ADELERSGT 17, PO BOX 2562, SOLLI, 0202 OSLO, NORWAY SN 0024-1164 J9 LETHAIA JI Lethaia PD SEP PY 2000 VL 33 IS 3 BP 190 EP 204 PG 15 WC Paleontology SC Paleontology GA 397PT UT WOS:000166704600005 ER PT J AU Kalfatovic, MR AF Kalfatovic, MR TI The art of arts: Rediscovering painting. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst Libs, Washington, DC 20560 USA. RP Kalfatovic, MR (reprint author), Smithsonian Inst Libs, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD SEP 1 PY 2000 VL 125 IS 14 BP 200 EP 200 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA 350FD UT WOS:000089089400040 ER PT J AU Harasewych, MG McArthur, AG AF Harasewych, MG McArthur, AG TI A molecular phylogeny of the Patellogastropoda (Mollusca : Gastropoda) SO MARINE BIOLOGY LA English DT Article ID PARTIAL 18S RDNA; EVOLUTIONARY TREES; MAXIMUM-LIKELIHOOD; HYDROTHERMAL VENTS; SEQUENCE DATA; DNA; LIMPET; ORDER AB Phylogenetic analyses of partial 18S rDNA sequences from species representing all living families of the order Patellogastropoda, most other major gastropod groups (Cocculiniformia, Neritopsina, Vetigastropoda, Caenogastropoda, Heterobranchia, but not Neomphalina), and two additional classes of the phylum Mollusca (Cephalopoda, Polyplacophora) confirm that Patellogastropoda comprises a robust clade with high statistical support. The sequences are characterized by the presence of several insertions and deletions that are unique to, and ubiquitous among, patellogastropods. However, this portion of the 18S gene is insufficiently informative to provide robust support for the monophyly of Gastropoda, or to address the division of the Gastropoda into the subclasses Eogastropoda (=Patellogastropoda + hypothetical coiled ancestors) and Orthogastropoda. These sequence data invariably group Patellogastropoda in a weakly supported clade with cocculiniform limpets, despite greater sequence divergences between Patellogastropoda and "Cocculiniformia" than between the Patellogastropoda and Orthogastropoda. Partial 18S sequences support the inclusion of the family Neolepetopsidae within the superfamily Acmaeoidea, and refute its previously hypothesized position as sister group to the remaining living Patellogastropoda. This region of the 18S rDNA gene diverges at widely differing rates, spanning an order of magnitude among patellogastropod lineages, and therefore does not provide meaningful resolution of the relationships among higher taxa of patellogastropods. Data from one or more genes that evolve more uniformly and more rapidly than the 18S rDNA gene (possibly one or more of the mitochondrial genes) seem more likely to be informative about relationships within Patellogastropoda. C1 Natl Museum Nat Hist, Dept Invertebrate Zool, Smithsonian Inst, Washington, DC 20560 USA. RP Harasewych, MG (reprint author), Natl Museum Nat Hist, Dept Invertebrate Zool, Smithsonian Inst, Washington, DC 20560 USA. NR 74 TC 28 Z9 29 U1 0 U2 7 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0025-3162 J9 MAR BIOL JI Mar. Biol. PD SEP PY 2000 VL 137 IS 2 BP 183 EP 194 DI 10.1007/s002270000332 PG 12 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 357PY UT WOS:000089511100001 ER PT J AU Russell, SS Davis, AM MacPherson, GJ Guan, YB Huss, GR AF Russell, SS Davis, AM MacPherson, GJ Guan, YB Huss, GR TI Refractory inclusions from the ungrouped carbonaceous chondrites MacAlpine Hills 87300 and 88107 SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID ALUMINUM-RICH INCLUSIONS; TRACE-ELEMENT ABUNDANCES; ALLENDE METEORITE; SOLAR NEBULA; ISOTOPIC ANOMALIES; CO3 METEORITES; PARENT BODY; HIBONITE; MINERALOGY; CM AB MacAlpine Hills (MAC) 87300 and 88107 are two unusual carbonaceous chondrites that are intermediate in chemical composition between the CO3 and CM2 meteorite groups. Calcium-aluminum-rich inclusions (CAIs) from these two meteorites are mostly spinel-pyroxene and melilite-rich (Type A) varieties. Spinel-pyroxene inclusions have either a banded or nodular texture, with aluminous diopside rimming Fe-poor spinel. Melilite-rich inclusions (Angstrom k(4-42)) are irregular in shape and contain minor spinel (FeO <1 wt%), perovskite and, more rarely, hibonite. The CAIs in MAC 88107 and 87300 are similar in primary mineralogy to cars from low petrologic grade CO3 meteorites but differ in that they commonly contain phyllosilicates. The two meteorites also differ somewhat from each other: melilite is more abundant and slightly more Al-rich in inclusions from MAC 88107 than in those from MAC 87300, and phyllosilicate is more abundant and Mg-poor in MAC 87300 CAIs relative to that in MAC 88107. These differences suggest that the two meteorites are not paired. The CAI sizes and the abundance of melilite-rich CAIs in MAC 88107 and 87300 suggests a genetic relationship to CO3 meteorites, but the CAIs in both have suffered a greater degree of aqueous alteration than is observed in CO meteorites. Aluminum-rich melilite in CAIs from both meteorites generally contains excess Mg-26, presumably from the in situ decay of Al-26. Although well-defined isochrons are not observed, the Mg-26 excesses are consistent with initial Al-26/Al-27 ratios of approximately 3-5 x 10(-5) An unusual hibonite-bearing inclusion is isotopically heterogeneous, with two large and abutting hibonite crystals showing significant differences in their degrees of mass-dependent fractionation of Mg-25/Mg-24. Th, two crystals also show differences in their inferred initial Al-26/Al-27 ratios, 1 x 10(-5) vs. less than or equal to 3 x 10(-6). C1 Smithsonian Inst, Museum Natl Hist Nat, Dept Mineral Sci, Washington, DC 20560 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. RP MacPherson, GJ (reprint author), Smithsonian Inst, Museum Natl Hist Nat, Dept Mineral Sci, Washington, DC 20560 USA. OI Davis, Andrew/0000-0001-7955-6236 NR 55 TC 13 Z9 14 U1 3 U2 8 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 IS 5 BP 1051 EP 1066 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 361RF UT WOS:000089736400018 ER PT J AU Ash, RD MacPherson, GJ Rumble, D AF Ash, RD MacPherson, GJ Rumble, D TI Oxygen isotopes, ureilite genesis, and the geology of asteroids. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Univ Oxford, Dept Earth Sci, Oxford OX1 3PR, England. Natl Museum Nat Hist, Smithsonian Inst, MRC NHB 119, Washington, DC 20560 USA. Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA. RI Galy, Albert/A-8518-2011 OI Galy, Albert/0000-0001-9978-4287 NR 4 TC 6 Z9 6 U1 1 U2 4 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A21 EP A22 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400013 ER PT J AU Burbine, TH McCoy, TJ Dickinson, TL AF Burbine, TH McCoy, TJ Dickinson, TL TI Origin of plagioclase-"enriched", igneous, enstatite meteorites. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID MELT ROCKS C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Mineral Sci, Washington, DC 20560 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. NR 8 TC 15 Z9 15 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A36 EP A36 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400042 ER PT J AU Burbine, TH Bowden, E Ogura, T Binzel, RP Bus, SJ McCoy, TJ Kondo, K AF Burbine, TH Bowden, E Ogura, T Binzel, RP Bus, SJ McCoy, TJ Kondo, K TI The nature of olivine asteroids. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Mineral Sci, Washington, DC 20560 USA. UCL, London WC1E 6BT, England. Tokyo Inst Technol, Mat & Struct Lab, Yokohama, Kanagawa 2268503, Japan. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A35 EP A36 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400041 ER PT J AU Bus, SJ Binzel, RP Burbine, TH AF Bus, SJ Binzel, RP Burbine, TH TI A new generation of asteroid taxonomy. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID CLASSIFICATION C1 MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Mineral Sci, Washington, DC 20560 USA. NR 8 TC 2 Z9 2 U1 1 U2 2 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A36 EP A37 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400043 ER PT J AU Davis, AM McKeegan, KD MacPherson, GJ AF Davis, AM McKeegan, KD MacPherson, GJ TI Oxygen-isotopic compositions of individual minerals from the FUN inclusion Vigarano 1623-5. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID ALLENDE INCLUSIONS; ANOMALIES; MAGNESIUM C1 Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. Natl Museum Nat Hist, Smithsonian Inst, Dept Mineral Sci, Washington, DC 20560 USA. RI McKeegan, Kevin/A-4107-2008 OI McKeegan, Kevin/0000-0002-1827-729X NR 6 TC 14 Z9 14 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A47 EP A47 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400065 ER PT J AU Fagan, TJ Bunch, TE Wittke, JH Jarosewich, E Clayton, RN Mayeda, T Eugster, O Lorenzetti, S Keil, K Taylor, GJ AF Fagan, TJ Bunch, TE Wittke, JH Jarosewich, E Clayton, RN Mayeda, T Eugster, O Lorenzetti, S Keil, K Taylor, GJ TI Northwest Africa 032, a new lunar mare basalt. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Univ Hawaii Manoa, Sch Ocean & Earth Sci & Technol, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. No Arizona Univ, Dept Geol, Flagstaff, AZ 86011 USA. Smithsonian Inst, Dept Mineral Sci, Washington, DC 20560 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Bern, Inst Phys, CH-3012 Bern, Switzerland. RI Lorenzetti, Silvio/B-1188-2009 OI Lorenzetti, Silvio/0000-0002-8339-8960 NR 5 TC 7 Z9 7 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A51 EP A52 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400075 ER PT J AU French, BM AF French, BM TI 2000 Barringer medal citation for Ralph B. Baldwin - 2000 August 28, Chicago, United States of America SO METEORITICS & PLANETARY SCIENCE LA English DT Biographical-Item C1 Smithsonian Inst, Dept Mineral Sci, Washington, DC 20560 USA. RP French, BM (reprint author), Smithsonian Inst, Dept Mineral Sci, MRC 119, Washington, DC 20560 USA. NR 1 TC 1 Z9 1 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A11 EP A11 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400006 ER PT J AU Guan, Y McKeegan, KD MacPherson, GJ AF Guan, Y McKeegan, KD MacPherson, GJ TI Oxygen-isotopic compositions in two calcium-aluminum-rich inclusions from unequilibrated ordinary chondrites. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Natl Museum Nat Hist, Smithsonian Inst, Dept Mineral Sci, Washington, DC 20560 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. RI McKeegan, Kevin/A-4107-2008 OI McKeegan, Kevin/0000-0002-1827-729X NR 6 TC 3 Z9 4 U1 0 U2 1 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A67 EP A67 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400103 ER PT J AU McCoy, TJ Dickinson, TL Burbine, TH AF McCoy, TJ Dickinson, TL Burbine, TH TI Rare earth elements in coexisting sulfides in the Allan Hills 84008 aubrite: Clues to aubrite genesis. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID IGNEOUS ORIGIN; OLDHAMITE C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Mineral Sci, Washington, DC 20560 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. NR 6 TC 2 Z9 2 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A105 EP A106 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400179 ER PT J AU Meibom, A Desch, SJ Petaev, MI Krot, AN Cuzzi, JN Wood, JA Keil, K AF Meibom, A Desch, SJ Petaev, MI Krot, AN Cuzzi, JN Wood, JA Keil, K TI An astrophysical model for the formation of zoned iron-nickel metal grains in the Bencubbin/CH-like chondrites Queen Alexandra range 94411 and Hammadah al Hamra 237. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Stanford Univ, Stanford, CA 94305 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Hawaii, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. NR 7 TC 3 Z9 3 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A107 EP A107 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400182 ER PT J AU Nittler, LR McCoy, TJ AF Nittler, LR McCoy, TJ TI Carbon isotopes in graphite from lodranite Graves Nunataks 95209. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Mineral Sci, Washington, DC 20560 USA. NR 5 TC 3 Z9 3 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A120 EP A121 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400207 ER PT J AU Petaev, MI Wood, JA AF Petaev, MI Wood, JA TI Silica nodules in calcium-aluminium-rich chondrules of the Kainsaz CO3 chondrite. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A126 EP A127 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400219 ER PT J AU Trombka, JI Nittler, LR Boynton, WV Bruckner, J Squyres, SW Arnold, JR Evans, LG Gorenstein, P Hurley, KC McCoy, TJ Reedy, RC Bailey, S Burbine, TH Bhangoo, JS Clark, PE Floyd, SR Gold, RE McClanahan, TP McCartney, E Goldsten, JO McNutt, RL Mikheeva, I Murphy, ME Starr, RD AF Trombka, JI Nittler, LR Boynton, WV Bruckner, J Squyres, SW Arnold, JR Evans, LG Gorenstein, P Hurley, KC McCoy, TJ Reedy, RC Bailey, S Burbine, TH Bhangoo, JS Clark, PE Floyd, SR Gold, RE McClanahan, TP McCartney, E Goldsten, JO McNutt, RL Mikheeva, I Murphy, ME Starr, RD TI The chemical composition of asteroid 433 Eros: Preliminary results of the NEAR Shoemaker X-Ray/Gamma-Ray Spectrometer. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA. Max Planck Inst Chem, D-55020 Mainz, Germany. Cornell Univ, Ithaca, NY 14853 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Comp Sci Corp, Syst Sci Div, Laurel, MD 20707 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. Univ Calif Berkeley, Space Sci Lab 7450, Berkeley, CA 94720 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Mineral Sci, Washington, DC 20560 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. RI McNutt, Ralph/E-8006-2010 OI McNutt, Ralph/0000-0002-4722-9166 NR 6 TC 0 Z9 0 U1 0 U2 1 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A159 EP A160 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400284 ER PT J AU Vicenzi, EP Heaney, PJ AF Vicenzi, EP Heaney, PJ TI Multiple martian fluids: The alteration sequence in the Lafayette SNC meteorite. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID CARBONATE C1 Natl Museum Nat Hist, Dept Mineral Sci, Smithsonian Inst, Washington, DC 20560 USA. Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. NR 5 TC 8 Z9 8 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2000 VL 35 SU S BP A164 EP A165 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 362PU UT WOS:000089787400293 ER PT J AU Duda, TF Palumbi, SR AF Duda, TF Palumbi, SR TI Evolutionary diversification of multigene families: Allelic selection of toxins in predatory cone snails SO MOLECULAR BIOLOGY AND EVOLUTION LA English DT Article DE multigene families; allelic diversification; four-loop conotoxins; Conus ID GENE DUPLICATION; NUCLEOTIDE SUBSTITUTION; OVERDOMINANT SELECTION; ODORANT RECEPTORS; CALCIUM CHANNELS; CONOTOXINS; DIVERSITY; BINDING; LOCI; RECOGNITION AB In order to investigate the evolution of conotoxin multigene families among two closely related vermivorous Conus species, we sequenced 104 four-loop conotoxin mRNAs from two individuals of Conus ebraeus and compared these with sequences already obtained from Conus abbreviatus. In contrast to the diversity of conotoxin sequences obtained from C. abbreviatus, only two common sequence variants were recovered from C. ebraeus. Segregation patterns of the variants in these two individuals and restriction digests of four-loop conotoxin amplification products from nine additional individuals suggest that the common variants are alleles from a single locus. These two putative alleles differ at nine positions that occur nonrandomly in the toxin-coding region of the sequences. Moreover, all substitutions are at nonsynonymous sites and are responsible for seven amino acid differences among the predicted amino acid sequences of the alleles. These results imply that conotoxin diversity is driven by strong diversifying selection and some form of frequency-dependent or overdominant selection at conotoxin loci, and they suggest that diverse conotoxin multigene families can originate from duplications at polymorphic loci. Furthermore, none of the sequences recovered from C. ebraeus appeared to be orthologs of loci from C. abbreviatus, and attempts to amplify orthologous sequences with locus-specific primers were unsuccessful among these species. These patterns suggest that venoms of closely related Conus species may differ due to the differential expression of conotoxin loci. C1 Harvard Univ, Dept Organism & Evolutionary Biol, Biol Labs, Cambridge, MA 02138 USA. RP Duda, TF (reprint author), Smithsonian Trop Res Inst, Naos Marine Lab, Apartado 2072, Balboa, Ancon, Panama. NR 44 TC 69 Z9 77 U1 0 U2 6 PU SOC MOLECULAR BIOLOGY EVOLUTION PI LAWRENCE PA PO BOX 1897, LAWRENCE, KS 66044-8897 USA SN 0737-4038 J9 MOL BIOL EVOL JI Mol. Biol. Evol. PD SEP PY 2000 VL 17 IS 9 BP 1286 EP 1293 PG 8 WC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity GA 350MA UT WOS:000089104100002 PM 10958845 ER PT J AU McCartney, MA Keller, G Lessios, HA AF McCartney, MA Keller, G Lessios, HA TI Dispersal barriers in tropical oceans and speciation in Atlantic and eastern Pacific sea urchins of the genus Echinometra SO MOLECULAR ECOLOGY LA English DT Article DE gene flow; Isthmus of Panama; marine speciation; mitochondrial DNA; phylogeny; phylogeography ID REPRODUCTIVE ISOLATION; MITOCHONDRIAL-DNA; GAMETIC INCOMPATIBILITY; MARINE SPECIATION; TREE TOPOLOGIES; EVOLUTION; PANAMA; ECHINOIDS; ISTHMUS; RATES AB Echinometra is a pantropical sea urchin made famous through studies of phylogeny, speciation, and genetic structure of the Indo-West Pacific (IWP) species. We sequenced 630 bp of the cytochrome oxidase I (COI) mitochondrial gene to provide comparable information on the eastern Pacific and Atlantic species, using divergence between those separated by closure of the Isthmus of Panama 3.1 million years ago (Ma) to estimate dates for cladogenic events. Most recently (1.27-1.62 Ma), the Atlantic species E. lucunter and E. viridis diverged from each other at a time in the Pleistocene that sea levels fell and Caribbean coral speciation and extinction rates were high. An earlier split, assumed to have been coincident with the completion of the Isthmus of Panama, separated the eastern Pacific E. vanbrunti from the Atlantic common ancestor. Transisthmian COI divergence similar to that in the sea urchin genus Eucidaris supports this assumption. The most ancient split in Echinometra occurred between the IWP and the neotropical clades, due to cessation of larval exchange around South Africa or across the Eastern Pacific Barrier. Gene now within species is generally high; however there are restrictions to genetic exchange between E. lucunter populations from the Caribbean and those from the rest of the Atlantic. Correlation between cladogenic and vicariant events supports E. Mayr's contention that marine species, despite their high dispersal potential, form by means of geographical separation. That sympatric, nonhybridizing E. lucunter and E. viridis were split so recently suggests, however, that perfection of reproductive barriers between marine species with large populations can occur in less than 1.6 million years (Myr). C1 Smithsonian Trop Res Inst, Balboa, Panama. RP McCartney, MA (reprint author), Univ N Carolina, Dept Biol Sci, 601 S Coll Rd, Wilmington, NC 28403 USA. NR 70 TC 140 Z9 147 U1 0 U2 26 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0962-1083 J9 MOL ECOL JI Mol. Ecol. PD SEP PY 2000 VL 9 IS 9 BP 1391 EP 1400 DI 10.1046/j.1365-294x.2000.01022.x PG 10 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 356BM UT WOS:000089424200019 PM 10972777 ER PT J AU Wooninck, LM Warner, RR Fleischer, RC AF Wooninck, LM Warner, RR Fleischer, RC TI Relative fitness components measured with competitive PCR SO MOLECULAR ECOLOGY LA English DT Article DE competitive PCR; microsatellites; paternity; sperm allocation ID BIFASCIATUM; GAMES; LOCI AB In mating systems with sperm competition, paternity is frequently established with modem DNA techniques. These methods are often expensive and cumbersome, and can be especially difficult for highly fecund species. An additional objective of many paternity studies is to discover the relationship between sperm number and paternity. We present here a competitive polymerase chain reaction (PCR) protocol, coupled with the use of an automated sequencer, that has two functions: (i) to measure directly relative sperm output of males in sperm competition; and (ii) to estimate paternity distributions of large numbers of offspring simultaneously. Our technique was calibrated using a microsatellite locus of the bluehead wrasse, Thalassoma bifasciatum, with the result that product ratio after competitive PCR accurately reflected the initial template proportions of known mixtures of DNA. When we applied our technique to multiple larvae of separate mating events we found that paternity distributions estimated with the competitive PCR technique closely matched the estimates derived from the traditional method of pooling paternity data from individual larvae. Finally, we compared paternity of these spawns with relative sperm contribution estimates. This comparison suggests that ejaculate size alone does not predict a male's proportion of paternity within the group. C1 Univ Calif Santa Barbara, Dept Ecol Evolut & Marine Biol, Santa Barbara, CA 93106 USA. Smithsonian Inst, Natl Zool Pk, Mol Genet Lab, Washington, DC 20008 USA. RP Wooninck, LM (reprint author), Univ Calif Santa Barbara, Dept Ecol Evolut & Marine Biol, Santa Barbara, CA 93106 USA. RI Warner, Robert/M-5342-2013 OI Warner, Robert/0000-0002-3299-5685 NR 16 TC 7 Z9 7 U1 0 U2 5 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0962-1083 J9 MOL ECOL JI Mol. Ecol. PD SEP PY 2000 VL 9 IS 9 BP 1409 EP 1414 DI 10.1046/j.1365-294x.2000.00984.x PG 6 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 356BM UT WOS:000089424200021 PM 10972779 ER PT J AU Zheng, XW Moran, JM Reid, MJ AF Zheng, XW Moran, JM Reid, MJ TI A milliarcsecond-resolution image of the OH masers in G34.3+0.2 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE masers; HII regions; ISM : individual : G34.3+0.2; ISM : magnetic fields; radio lines : ISM ID H-II REGIONS; PHYSICAL-PROPERTIES; VLA OBSERVATIONS; MOLECULAR CORE; RECOMBINATION; DYNAMICS; AMMONIA; LINES AB We present measurements of the distribution of the OH masers at 1665 and 1667 MHz towards the cometary ultracompact H II region in the complex G34.3+0.2. The results are based on observations made in both senses of circular polarization with a very long baseline interferometry (VLBI) array having an angular resolution of 5x20 mas(2). 38 maser features are identified in the region. 33 of these lie on an arc at the edge of the cometary H II region. Five are located in a cluster offset toward the north-east by 3 arcsec, and are probably associated with an independent ultracompact H II region. There is a velocity gradient of 30 km s(-1) pc(-1) across the arc. We identify five Zeeman pairs and determine that the magnetic field varies between 1 and 7 mG, but is always directed away from the Earth. The OH masers may arise in clumps in a shell of gas in a bow shock caused by the motion of the exciting star through the molecular cloud. The stand-off distance and the thickness of the shocked shell are roughly consistent with those predicted by such a bow-shock model. Also, the position of the exciting star(s), as estimated from the focus of the parabolic bow shock, closely matches that of the peak emission from the cometary H II region. However, the north-south velocity gradient in the ionized material remains difficult to explain in the context of the bow-shock model. C1 Nanjing Univ, Dept Astron, Nanjing 210093, Peoples R China. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Zheng, XW (reprint author), Nanjing Univ, Dept Astron, Nanjing 210093, Peoples R China. NR 23 TC 5 Z9 5 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD SEP 1 PY 2000 VL 317 IS 1 BP 192 EP 198 DI 10.1046/j.1365-8711.2000.03630.x PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 350LQ UT WOS:000089102800026 ER PT J AU Scappini, F Cecchi-Pestellini, C Codella, C Dalgarno, A AF Scappini, F Cecchi-Pestellini, C Codella, C Dalgarno, A TI Detection of HCO+ towards cygnus OB2No. 12 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE stars : individual : Cygnus OB2No. 12; ISM : abundances; ISM : clouds; ISM : molecules ID DIFFUSE INTERSTELLAR-MEDIUM; H-3(+); ASSOCIATION; LINE AB HCO+ has been detected for the first time towards the star Cygnus OB2 No. 12 through emission of the 1-0 rotational transition at 89 GHz. The CO(J=2-1) transition has also been observed. The observations are consistent with a model of dense regions embedded in a low-density clump gas. If actually present, the dense component would have an aggregate size L less than or equal to 1300 au, in agreement with estimates of small-scale density fluctuations observed along diffuse lines of sight. C1 CNR, Ist Spettroscopia Mol, I-40129 Bologna, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Florence, Dipartimento Astron & Sci Spazio, I-50125 Florence, Italy. CNR, Ist Fis Spazio Interplanetario, I-00133 Rome, Italy. RP Scappini, F (reprint author), CNR, Ist Spettroscopia Mol, Via P Gobetti 101, I-40129 Bologna, Italy. NR 21 TC 14 Z9 14 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD SEP 1 PY 2000 VL 317 IS 1 BP L6 EP L10 DI 10.1046/j.1365-8711.2000.03799.x PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 350LQ UT WOS:000089102800002 ER PT J AU Guainazzi, M Fiore, F Giallongo, E Laor, A Elvis, R Siemiginowska, A AF Guainazzi, M Fiore, F Giallongo, E Laor, A Elvis, R Siemiginowska, A TI An exploratory study of the hard X-ray variability properties of PG quasars with RXTE SO NEW ASTRONOMY REVIEWS LA English DT Article; Proceedings Paper CT Joint MPE/AIP/ESO Workshop on Observational and Theoretical Progress in the Study of Narrow-Line Seyfert 1 Galaxies CY DEC 08-11, 1999 CL PHYSIKZENTRUM, BAN HONNEF, GERMANY SP MPE, AIP, ESO HO PHYSIKZENTRUM DE galaxies : active; quasars : general; X-rays : galaxies AB We have monitored with the RXTE PCA the variability pattern of the 2-20 keV flux in four PG quasars (QSOs) from the Laor et al. (1994) sample. Six observations of each target at regular intervals of 1 day were performed. The sample comprises objects with extreme values of Balmer line width (and hence soft X-ray steepness) and spans about one order of magnitude in luminosity, The most robust result is that the variability amplitude decreases as energy increases. Several options for a possible ultimate driver of the soft and hard X-ray variability, such as the influx rate of Comptonizing relativistic particles, instabilities in the accretion flow or the number of X-ray 'active sites', are consistent with our results. (C) 2000 Elsevier Science B.V. All rights reserved. C1 ESA, VILSPA, XMM SOC, E-28080 Madrid, Spain. Osservatorio Astron Roma, I-00040 Monte Porzio Catone, Italy. Technion Israel Inst Technol, Dept Phys, IL-32000 Haifa, Israel. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Guainazzi, M (reprint author), ESA, VILSPA, XMM SOC, Apartado 50727, E-28080 Madrid, Spain. OI Giallongo, Emanuele/0000-0003-0734-1273; Fiore, Fabrizio/0000-0002-4031-4157 NR 7 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1387-6473 J9 NEW ASTRON REV JI New Astron. Rev. PD SEP PY 2000 VL 44 IS 7-9 BP 415 EP 417 DI 10.1016/S1387-6473(00)00070-1 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 367ET UT WOS:000090049300007 ER PT J AU Peterson, BM McHardy, IM Wilkes, BJ AF Peterson, BM McHardy, IM Wilkes, BJ TI Variability of NGC 4051 and the nature of narrow-line Seyfert 1 galaxies SO NEW ASTRONOMY REVIEWS LA English DT Article; Proceedings Paper CT Joint MPE/AIP/ESO Workshop on Observational and Theoretical Progress in the Study of Narrow-Line Seyfert 1 Galaxies CY DEC 08-11, 1999 CL PHYSIKZENTRUM, BAN HONNEF, GERMANY SP MPE, AIP, ESO HO PHYSIKZENTRUM DE black hole masses; accretion disk; optical emission-line variability ID ACTIVE GALACTIC NUCLEI; X-RAY VARIABILITY; BLACK-HOLES; NGC-4051; MODEL; QUASARS; REGION; DISKS AB We report on a three-year program of coordinated X-ray and optical monitoring of the narrow-line Seyfert 1 galaxy NGC 4051. The rapid continuum variations observed in the X-ray fluxes are not detected in the optical, although the X-ray and optical continuum fluxes are correlated on time scales of many weeks and longer. Variations in the flux of the broad H beta line are found to lag behind the optical continuum variations by approximately 6 days (with an uncertainty of 2-3 days), and combining this with the line width yields a virial mass estimate of similar to1.1 x 10(6) M-., at the very low end of the distribution of AGN masses measured by line reverberation. Strong variability of Hell lambda 4686 is also detected, and the response time measured is similar to that of H beta, but with a much larger uncertainty. The Hell lambda 4686 line is almost five times broader than H beta, and it is strongly blueward asymmetric, as are the hi,oh-ionization UV lines recorded in archive spectra of NGC 4051. The data are consistent with the Balmer lines arising in a low-inclination (nearly face-on) disk-like configuration, and the high-ionization lines arising in an outflowing wind, of which we observe preferentially the near side. During the third year of monitoring, both the X-ray continuum and the Hell lambda 4686 line went into extremely low states, although the optical continuum and the H beta broad line were both still present and variable. We suggest that the inner part of the accretion disk may have gone into an advection-dominated state, yielding little radiation from the hotter inner disk. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Ohio State Univ, Dept Astron, Ohio, OH USA. Univ Southampton, Dept Phys & Astron, Southampton, Hants, England. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Peterson, BM (reprint author), Ohio State Univ, Dept Astron, Ohio, OH USA. OI Wilkes, Belinda/0000-0003-1809-2364 NR 18 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1387-6473 J9 NEW ASTRON REV JI New Astron. Rev. PD SEP PY 2000 VL 44 IS 7-9 BP 491 EP 496 DI 10.1016/S1387-6473(00)00086-5 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 367ET UT WOS:000090049300023 ER PT J AU Elvis, M AF Elvis, M TI A structure for quasars SO NEW ASTRONOMY REVIEWS LA English DT Article; Proceedings Paper CT Joint MPE/AIP/ESO Workshop on Observational and Theoretical Progress in the Study of Narrow-Line Seyfert 1 Galaxies CY DEC 08-11, 1999 CL PHYSIKZENTRUM, BAN HONNEF, GERMANY SP MPE, AIP, ESO HO PHYSIKZENTRUM DE galaxies : active; quasars : general; quasars : absorption lines AB We propose a simple unifying structure for the inner regions of quasars and AGN. This empirically derived model links together the BALs, the narrow UV/X-ray ionized absorbers, the BELR, and the Compton scattering/fluorescing regions into a single structure. The model also suggests an origin for the large-scale bi-conical outflows. Some other potential implications of this structure are discussed. Published by Elsevier Science B.V. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Elvis, M (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 9 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1387-6473 J9 NEW ASTRON REV JI New Astron. Rev. PD SEP PY 2000 VL 44 IS 7-9 BP 559 EP 562 DI 10.1016/S1387-6473(00)00099-3 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 367ET UT WOS:000090049300036 ER PT J AU Nicastro, F Elvis, M AF Nicastro, F Elvis, M TI A new model for the width of the broad emission lines in AGN - The role of the accretion rate SO NEW ASTRONOMY REVIEWS LA English DT Article; Proceedings Paper CT Joint MPE/AIP/ESO Workshop on Observational and Theoretical Progress in the Study of Narrow-Line Seyfert 1 Galaxies CY DEC 08-11, 1999 CL PHYSIKZENTRUM, BAN HONNEF, GERMANY SP MPE, AIP, ESO HO PHYSIKZENTRUM DE galaxies : active; quasars : general ID ACTIVE GALACTIC NUCLEI; REGION; NGC-5548 AB We present a model which relates the Broad Emission Line Regions of AGN to the accretion mechanism. Based on the Keplerian assumption for the high velocity clouds of the gas responsible for the production of the Broad Emission Lines, we identify that gas with an outflowing disk/coronal wind from a stabilized Shakura-Sunyaev accretion disk. We show that in the framework of this picture the observed range of H beta FWHM from Broad Line to Narrow Line type 1 AGN, is well reproduced as a function of the accretion rate. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Nicastro, F (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI Nicastro, Fabrizio/0000-0002-6896-1364 NR 9 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1387-6473 J9 NEW ASTRON REV JI New Astron. Rev. PD SEP PY 2000 VL 44 IS 7-9 BP 569 EP 571 DI 10.1016/S1387-6473(00)00101-9 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 367ET UT WOS:000090049300038 ER PT J AU Kuraszkiewicz, JK Wilkes, BJ Czerny, B Mathur, S Brandt, WN Vestergaard, M AF Kuraszkiewicz, JK Wilkes, BJ Czerny, B Mathur, S Brandt, WN Vestergaard, M TI The UV spectra of NLS1s - implications for their broad line regions SO NEW ASTRONOMY REVIEWS LA English DT Article; Proceedings Paper CT Joint MPE/AIP/ESO Workshop on Observational and Theoretical Progress in the Study of Narrow-Line Seyfert 1 Galaxies CY DEC 08-11, 1999 CL PHYSIKZENTRUM, BAN HONNEF, GERMANY SP MPE, AIP, ESO HO PHYSIKZENTRUM DE galaxies : active; quasars : emission lines ID ACTIVE GALACTIC NUCLEI; RADIO GALAXIES; SEYFERT-GALAXY; QUASARS AB We study the UV spectra of NLS1 galaxies and compare them with typical Seyfert 1 galaxies and quasars. The NLS1 spectra show narrower UV lines as well as weaker CIV lambda 1549 and CIII] lambda 1909 emission. We show that these Line properties are due to a lower ionization parameter and somewhat higher BLR cloud densities. These modified conditions can be explained by the hotter big blue bumps observed in NLS1s, which are in turn due to higher L/L-Edd ratios, as shown by our accretion disk and corona modeling of the NLS1 continua. We also present evidence that the Boroson and Green eigenvector 1, which is correlated with the optical and UV emission-line properties, is not driven by orientation and hence NLS1s, which have extreme eigenvector 1 values, are not viewed from an extreme viewing angle. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. N Copernicus Astron Ctr, Warsaw, Poland. Ohio State Univ, Columbus, OH 43120 USA. Penn State Univ, University Pk, PA 16802 USA. RP Kuraszkiewicz, JK (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Czerny, Bozena/A-2363-2015; Vestergaard, Marianne/M-5247-2014; Brandt, William/N-2844-2015; OI Czerny, Bozena/0000-0001-5848-4333; Vestergaard, Marianne/0000-0001-9191-9837; Brandt, William/0000-0002-0167-2453; Wilkes, Belinda/0000-0003-1809-2364 NR 12 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1387-6473 J9 NEW ASTRON REV JI New Astron. Rev. PD SEP PY 2000 VL 44 IS 7-9 BP 573 EP 575 DI 10.1016/S1387-6473(00)00102-0 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 367ET UT WOS:000090049300039 ER PT J AU Wasshausen, DC AF Wasshausen, DC TI A new species of Justicia (Acanthaceae) from Venezuela SO NOVON LA English DT Article AB Current floristic research in Venezuela has resulted in the recognition of another new species of Justicia. This new species, Justicia aymardii, presently known from the slopes of the eastern Andes, the Sierra Nevada de Merida, is described, illustrated, and compared to its closest relative, Justicia ischnorhachis Leonard, which is from Colombia. It alone among Justicia has the combination of (1) a 4-parted calyx, (2) multicellular purplish colored trichomes along the stem, peduncles, and rachis, and (3) a conspicuous purplish to reddish purple, long, somewhat curved, tubular corolla (20-28 mm long) with relatively short lips (8-9 mm long). This new species does not appear to be closely related to any of the known species of Justicia from Venezuela. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, Washington, DC 20560 USA. RP Wasshausen, DC (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, Washington, DC 20560 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU MISSOURI BOTANICAL GARDEN PI ST LOUIS PA 2345 TOWER GROVE AVENUE, ST LOUIS, MO 63110 USA SN 1055-3177 J9 NOVON JI Novon PD FAL PY 2000 VL 10 IS 3 BP 260 EP 263 DI 10.2307/3393110 PG 4 WC Plant Sciences SC Plant Sciences GA 355KU UT WOS:000089385500014 ER PT J AU Dakora, FD Drake, BG AF Dakora, FD Drake, BG TI Elevated CO2 stimulates associative N-2 fixation in a C-3 plant of the Chesapeake Bay wetland SO PLANT CELL AND ENVIRONMENT LA English DT Article DE elevated CO2; C-3 and C-4 species; N-2 fixation; A % X (atom % N-15 excess) ID ATMOSPHERIC CO2; NITROGEN-FIXATION; SCIRPUS-OLNEYI; CARBON-DIOXIDE; ESTUARINE MARSH; GROWTH; PHOTOSYNTHESIS; ENRICHMENT; NUTRITION; FIELD AB In this study, the response of N-2 fixation to elevated CO2 was measured in Scirpus olneyi, a C-3 sedge, and Spartina patens, a C-4 grass, using acetylene reduction assay and N-15(2) gas feeding, Field plants grown in PVC tubes (25 cm long, 10 cm internal diameter) were used. Exposure to elevated CO2 significantly (P < 0.05) caused a 35% increase in nitrogenase activity and 73% increase in N-15 incorporated by Scirpus olneyi, In Spartina patens, elevated CO2 (660 1 mu mol mol(-1)) increased nitrogenase activity and N-15 incorporation by 13 and 23%, respectively. Estimates showed that the rate of N-2 fixation in Scirpus olneyi under elevated CO2 was 611 +/- 75 ng N-15 fixed plant(-1) h(-1) compared with 367 +/- 46 ng N-15 fixed plant(-1) h(-1) in ambient CO2 plants. In Spartina patens, however, the rate of N-2 fixation was 12.5 +/- 1.1 versus 9.8 +/- 1.3 ng N-15 fixed plant(-1) h(-1) for elevated and ambient CO2, respectively. Heterotrophic non-symbiotic N-2 fixation in plant-free marsh sediment also increased significantly (P < 0.05) with elevated CO2. The proportional increase in N-15(2) fixation correlated with the relative stimulation of photosynthesis, in that N-2 fixation was high in the C-2 plant in which photosynthesis was also high, and lower in the C-4 plant in which photosynthesis was relatively less stimulated by growth in elevated CO2, These results are consistent with the hypothesis that carbon fixation in C-3 species, stimulated by rising CO2, is likely to provide additional carbon to endophytic and below-ground microbial processes. C1 Univ Cape Town, Dept Bot, ZA-7701 Cape Town, South Africa. Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. RP Dakora, FD (reprint author), Univ Cape Town, Dept Bot, ZA-7701 Cape Town, South Africa. NR 40 TC 26 Z9 30 U1 0 U2 10 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0140-7791 J9 PLANT CELL ENVIRON JI Plant Cell Environ. PD SEP PY 2000 VL 23 IS 9 BP 943 EP 953 DI 10.1046/j.1365-3040.2000.00610.x PG 11 WC Plant Sciences SC Plant Sciences GA 382DG UT WOS:000165802700005 ER PT J AU Post, JE AF Post, JE TI Status of the reference X-ray powder diffraction patterns for the serpentine minerals in the PDF database-1997 - Comment SO POWDER DIFFRACTION LA English DT Letter C1 Smithsonian Inst, Natl Gem & Mineral Collect, Washington, DC 20560 USA. RP Post, JE (reprint author), Smithsonian Inst, Natl Gem & Mineral Collect, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 1 U2 2 PU J C P D S-INT CENTRE DIFFRACTION DATA PI NEWTOWN SQ PA 12 CAMPUS BLVD, NEWTOWN SQ, PA 19073-3273 USA SN 0885-7156 J9 POWDER DIFFR JI Powder Diffr. PD SEP PY 2000 VL 15 IS 3 BP 198 EP 198 PG 1 WC Materials Science, Characterization & Testing SC Materials Science GA 353YP UT WOS:000089303300009 ER PT J AU Hormiga, G Scharff, N Coddington, JA AF Hormiga, G Scharff, N Coddington, JA TI The phylogenetic basis of sexual size dimorphism in orb-weaving spiders (Araneae, Orbiculariae) SO SYSTEMATIC BIOLOGY LA English DT Review DE Araneae; continuous characters; Orbiculariae; parsimony; sexual size dimorphism; spiders ID PARSIMONY RECONSTRUCTIONS; ANCESTRAL STATES; CHARACTER STATES; ARANEIDAE; EVOLUTION; CANNIBALISM; TREES; TETRAGNATHIDAE; CONSEQUENCES; BEHAVIOR AB Extreme sexual body size dimorphism (SSD), in which males are only a small fraction of the size of the females, occurs only in a few, mostly marine, taxonomic groups. Spiders are the only terrestrial group in which small males are relatively common, particularly among orb-weavers (especially in the families Tetragnathidae and Araneidae) and crab spiders (Thomisidae). We used a taxonomic sample of 80 genera to study the phylogenetic patterns (origins and reversals) of SSD in ort-weaving spiders (Orbiculariae). We collected and compiled male and female size data (adult body length) for 536 species. Size data were treated as a continuous character, and ancestral sizes, for males and females separately, were reconstructed by using Wagner parsimony on a cladogram for the 80 genera used in this study Of these 80 genera, 24 were female-biased dimorphic (twice or more the body length of the male); the remaining 56 genera were monomorphic. Under parsimony only four independent origins of dimorphism are required: in the theridiid genus Tidarren, in the distal nephilines, in the "argiopoid clade," and in the araneid genus Kaira. Dimorphism has reversed to monomorphism at least seven times, all of them within the large "argiopoid clade." The four independent origins of dimorphism represent two separate instances of an increase in female size coupled with a decrease of male size (involving only two genera), and two separate instances of an increase in female size with male size either remaining the same or increasing, but not as much as females (involving 30 genera). In orb-weaving spiders, far more taxa are sexually dimorphic as a result of female size increase (22 genera) than as a result of male size decrease (two genera). SSD in orb-weaving spiders encompasses several independent evolutionary histories that together suggest a variety of evolutionary pathways. This multiplicity strongly refutes all efforts thus far to find a general explanation for either the origin or maintenance (or both) of SSD, because the different pathways very likely will require distinctly different, possibly unique, explanations. Each pattern must be understood historically before its origin and maintenance can be explained in ecological and evolutionary terms. The most frequently cited example of male dwarfism in spiders, the golden orb-weaving spider genus Nephila (Tetragnathidae), is in fact a case of female giantism, not male dwarfism. C1 George Washington Univ, Dept Biol Sci, Washington, DC 20052 USA. Smithsonian Inst, Museum Natl Hist Nat, Dept Entomol, Washington, DC 20560 USA. Univ Copenhagen, Zool Museum, Dept Entomol, DK-2100 Copenhagen, Denmark. RP Hormiga, G (reprint author), George Washington Univ, Dept Biol Sci, Washington, DC 20052 USA. EM hormiga@gwu.edu RI Hormiga, Gustavo/C-3874-2009; Scharff, Nikolaj/A-4787-2013 OI Scharff, Nikolaj/0000-0001-6809-2878 NR 138 TC 127 Z9 128 U1 2 U2 24 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1063-5157 J9 SYST BIOL JI Syst. Biol. PD SEP PY 2000 VL 49 IS 3 BP 435 EP 462 PG 28 WC Evolutionary Biology SC Evolutionary Biology GA 355TT UT WOS:000089405100004 PM 12116421 ER PT J AU Wilgenbusch, J de Queiroz, K AF Wilgenbusch, J de Queiroz, K TI Phylogenetic relationships among the phrynosomatid sand lizards inferred from mitochondrial DNA sequences generated by heterogeneous evolutionary processes SO SYSTEMATIC BIOLOGY LA English DT Article DE combining data; cytochrome b; maximum likelihood; mitochondrial DNA; phrynosomatidae; phylogeny; 12S RNA; sand lizards ID SITE RATE VARIATION; 12S RIBOSOMAL-RNA; CYTOCHROME-B GENE; SECONDARY STRUCTURE; COMBINING DATA; GENOME; SUBSTITUTIONS; INFERENCE; ALIGNMENT; TRANSITIONS AB Nucleotide sequences of the mitochondrial protein coding cytochrome b (cyt b; 650 bp) and small-subunit 12S ribosomal RNA (similar to 350 bp) genes were used in analyses of phylogenetic relationships among extant phrynosomatid sand lizards, including an examination of competing hypotheses regarding the evolution of "earlessness." Sequences were obtained from all currently recognized species of sand lizards as well as representatives of the first and second outgroups and analyzed using both parsimony and likelihood methods. The cyt b data offer strong support for relationships that correspond with relatively recent divergences and moderate to low support for relationships reflecting more ancient divergences within the clade. These data support monophyly of the "earless" taxa, the placement of Uma as the sister taxon to the other sand lizards, and monophyly of all four taxa traditionally ranked as genera. All well-supported relationships in the 12S phylogeny are completely congruent with well-supported relationships in the cyt b phylogeny; however, the 12S data alone provide very little support for deeper divergences. Phylogenetic relationships within species are concordant with geography and suggest patterns of phylogeographic differentiation, including the conclusion that at least one currently recognized species (Holbrookia maculata) actually consists of more than one species; By independently optimizing likelihood model parameters for various subsets of the data, we found that nucleotide substitution processes vary widely between genes and among the structural and functional regions or classes of sites within each gene. Therefore, we compared competing phylogenetic hypotheses, using parameter estimates specific to those subsets, analyzing the subsets separately and in various combinations. The hypothesis supported by the cyt b data was favored over rival hypotheses in all but one of the five comparisons made with the entire data set, including the set of partitions that best explained the data, although we were unable to confidently reject (P < 0.05) alternative hypotheses. Our results highlight the importance of optimizing models and parameter estimates for different genes or parts thereof-a strategy that takes advantages of the strengths of both combining and partitioning data. C1 Smithsonian Inst, Lab Mol Systemat, MSC, Washington, DC 20560 USA. Smithsonian Inst, Museum Natl Hist Nat, Dept Invertebrate Zool, Washington, DC 20560 USA. RP Wilgenbusch, J (reprint author), Smithsonian Inst, Lab Mol Systemat, MSC, MRC 534, Washington, DC 20560 USA. NR 83 TC 59 Z9 59 U1 1 U2 10 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 1063-5157 J9 SYST BIOL JI Syst. Biol. PD SEP PY 2000 VL 49 IS 3 BP 592 EP 612 PG 21 WC Evolutionary Biology SC Evolutionary Biology GA 355TT UT WOS:000089405100012 PM 12116429 ER PT J AU Laurance, WF AF Laurance, WF TI Edge effects and ecological processes: are they on the same scale? Reply SO TRENDS IN ECOLOGY & EVOLUTION LA English DT Letter C1 Smithsonian Trop Res Inst, Balboa, Panama. Natl Inst Amazonian Res, Biol Dynam Forest Fragments Project, BR-69011970 Manaus, Amazonas, Brazil. RP Laurance, WF (reprint author), Smithsonian Trop Res Inst, Apartado 2072, Balboa, Panama. RI Laurance, William/B-2709-2012 NR 7 TC 1 Z9 1 U1 1 U2 5 PU ELSEVIER SCIENCE LONDON PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 0169-5347 J9 TRENDS ECOL EVOL JI Trends Ecol. Evol. PD SEP PY 2000 VL 15 IS 9 BP 373 EP 373 DI 10.1016/S0169-5347(00)01916-9 PG 1 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA 346GQ UT WOS:000088863000015 ER PT J AU Graves, GR AF Graves, GR TI Costs and benefits of Web access to museum data SO TRENDS IN ECOLOGY & EVOLUTION LA English DT Letter C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Vertebrate Zool, Washington, DC 20560 USA. RP Graves, GR (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Vertebrate Zool, Washington, DC 20560 USA. NR 2 TC 11 Z9 11 U1 0 U2 1 PU ELSEVIER SCIENCE LONDON PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 0169-5347 J9 TRENDS ECOL EVOL JI Trends Ecol. Evol. PD SEP PY 2000 VL 15 IS 9 BP 374 EP 374 DI 10.1016/S0169-5347(00)01918-2 PG 1 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA 346GQ UT WOS:000088863000016 ER PT J AU Fleischer, RC AF Fleischer, RC TI Cuckoos, cowbirds and other cheats SO NATURE LA English DT Book Review C1 Smithsonian Inst, Natl Zool Pk, Washington, DC 20008 USA. RP Fleischer, RC (reprint author), Smithsonian Inst, Natl Zool Pk, Washington, DC 20008 USA. NR 1 TC 0 Z9 0 U1 7 U2 27 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD AUG 31 PY 2000 VL 406 IS 6799 BP 937 EP 938 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 348ZW UT WOS:000089020200019 ER PT J AU Reid, RP Visscher, PT Decho, AW Stolz, JF Bebout, BM Dupraz, C Macintyre, LG Paerl, HW Pinckney, JL Prufert-Bebout, L Steppe, TF DesMarais, DJ AF Reid, RP Visscher, PT Decho, AW Stolz, JF Bebout, BM Dupraz, C Macintyre, LG Paerl, HW Pinckney, JL Prufert-Bebout, L Steppe, TF DesMarais, DJ TI The role of microbes in accretion, lamination and early lithification of modern marine stromatolites SO NATURE LA English DT Article ID SUBTIDAL STROMATOLITES; EXUMA-CAYS; BAHAMAS; MATS; COMMUNITIES AB For three billion years, before the Cambrian diversification of life, laminated carbonate build-ups called stromatolites were widespread in shallow marine seas(1,2). These ancient structures are generally thought to be microbial in origin and potentially preserve evidence of the Earth's earliest biosphere(1-3). Despite their evolutionary significance, little is known about stromatolite formation, especially the relative roles of microbial and environmental factors in stromatolite accretion(1,3). Here we show that growth of modern marine stromatolites represents a dynamic balance between sedimentation and intermittent lithification of cyanobacterial mats. Periods of rapid sediment accretion, during which stromatolite surfaces are dominated by pioneer communities of gliding filamentous cyanobacteria, alternate with hiatal intervals. These discontinuities in sedimentation are characterized by development of surface films of exopolymer and subsequent heterotrophic bacterial decomposition, forming thin crusts of microcrystalline carbonate. During prolonged hiatal periods, climax communities develop, which include endolithic coccoid cyanobacteria. These coccoids modify the sediment, forming thicker lithified laminae. Preservation of lithified layers at depth creates millimetre-scale lamination. This simple model of modern marine stromatolite growth may be applicable to ancient stromatolites. C1 Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, MGG, Miami, FL 33149 USA. Univ Connecticut, Dept Marine Sci, Groton, CT 06340 USA. Univ S Carolina, Sch Publ Hlth, Columbia, SC 29208 USA. Duquesne Univ, Dept Biol Sci, Pittsburgh, PA 15282 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Smithsonian Inst, Natl Museum Nat Hist, Washington, DC 20560 USA. Univ N Carolina, Inst Marine Sci, Morehead City, NC 28557 USA. Texas A&M Univ, Dept Oceanog, College Stn, TX 77843 USA. RP Reid, RP (reprint author), Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, MGG, 4600 Rickenbacker Causeway, Miami, FL 33149 USA. OI Visscher, Pieter/0000-0001-6911-1532 NR 30 TC 390 Z9 432 U1 10 U2 100 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD AUG 31 PY 2000 VL 406 IS 6799 BP 989 EP 992 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 348ZW UT WOS:000089020200043 PM 10984051 ER PT J AU Hussein, MS Kharchenko, V Canto, LF Donangelo, R AF Hussein, MS Kharchenko, V Canto, LF Donangelo, R TI Long-range excitation of collective modes in mesoscopic metal clusters SO ANNALS OF PHYSICS LA English DT Article ID PARTICLE AB We develop a semiclassical theory for the long-range excitation of plasmon resonances in atomic clusters based on the doorway hypothesis. The effect of the width of the plasmon resonance is fully taken into account. As an application we study plasmon excitation in small sodium clusters in collisions with electrons and protons. (C) 2000 Academic Press. C1 Univ Sao Paulo, Inst Fis, BR-05315970 Sao Paulo, Brazil. Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02136 USA. Fed Univ Rio De Janeiro, Inst Fis, BR-21945970 Rio De Janeiro, Brazil. RP Hussein, MS (reprint author), Univ Sao Paulo, Inst Fis, CP 66318, BR-05315970 Sao Paulo, Brazil. RI Canto, Luiz /I-3733-2012 NR 12 TC 12 Z9 12 U1 1 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0003-4916 J9 ANN PHYS-NEW YORK JI Ann. Phys. PD AUG 25 PY 2000 VL 284 IS 1 BP 178 EP 194 DI 10.1006/aphy.2000.6067 PG 17 WC Physics, Multidisciplinary SC Physics GA 352TW UT WOS:000089234800007 ER PT J AU Craddock, RA Howard, AD AF Craddock, RA Howard, AD TI Simulated degradation of lunar impact craters and a new method for age dating farside mare deposits SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID CLEMENTINE MISSION; MOON; PHOTOCLINOMETRY; REGIONS AB With the advent of Clementine data it is now possible to determine the lithology and extent of geologic materials on the Moon, particularly the farside mare deposits. However, traditional crater counting techniques do not provide reliable age estimates of these materials owing to their small surface areas, To support such studies, we present a model for estimating their age by analyzing the morphometry of degraded craters 1-3 km in diameter. A photoclinometric model was adapted for use with monoscopic 0.750-mu m ultraviolet-visible and high-resolution images where we extracted the topography of fresh craters. A two-dimensional computer model simulating linear diffusional creep was applied to fresh craters at a variety of diameters. The resulting profiles were then compared to photoclinometric profiles of degraded craters of known ages for calibration. Application of the resulting model to degraded craters in the mare deposit of the central Apollo basin (-36.5 degrees latitude, 208.0 degrees longitude) indicates that this material was emplaced during the early Imbrian period (similar to 3.85 Ga). By calculating the amount of material eroded from each of the degraded craters observed in this unit, the average erosion rate is estimated to be 2.0+/-0.1 x 10(-7) mm/yr on the Moon since the Imbrian. The estimated amount of material eroded during any given period suggests that the erosion rate has decreased with time, implying that the flux of larger impactors has as well. C1 Smithsonian Inst, Natl Air & Space Museum, Ctr Earth & Planetary Studies, Washington, DC 20560 USA. Univ Virginia, Dept Environm Sci, Charlottesville, VA 22903 USA. RP Craddock, RA (reprint author), Smithsonian Inst, Natl Air & Space Museum, Ctr Earth & Planetary Studies, Room 3776,MRC-315, Washington, DC 20560 USA. RI Craddock, Robert/B-3884-2013; OI Howard, Alan/0000-0002-5423-1600 NR 50 TC 25 Z9 25 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD AUG 25 PY 2000 VL 105 IS E8 BP 20387 EP 20401 DI 10.1029/1999JE001099 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 348TY UT WOS:000089003600016 ER PT J AU Towe, KM AF Towe, KM TI The archean atmosphere and sedimentary sulfides SO SCIENCE LA English DT Letter ID OXYGEN; EVOLUTION; OCEANS C1 Smithsonian Inst, Tennille, GA 31089 USA. RP Towe, KM (reprint author), Smithsonian Inst, 230 W Adams St, Tennille, GA 31089 USA. RI Thamdrup, Bo/F-3889-2016 OI Thamdrup, Bo/0000-0002-1221-7077 NR 12 TC 3 Z9 3 U1 0 U2 1 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD AUG 25 PY 2000 VL 289 IS 5483 BP 1297 EP 1297 DI 10.1126/science.289.5483.1297 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 347RF UT WOS:000088942400020 PM 10979853 ER PT J AU Guan, YB Huss, GR MacPherson, GJ Wasserburg, GJ AF Guan, YB Huss, GR MacPherson, GJ Wasserburg, GJ TI Calcium-aluminum-rich inclusions from enstatite chondrites: Indigenous or foreign? SO SCIENCE LA English DT Article ID EARLY SOLAR-SYSTEM; AL-26; METEORITES; ABUNDANCES; ALLENDE; OXYGEN AB The primary mineral assemblages and initial Al-26/Al-27 ratios of rare calcium-aluminum-rich inclusions (CAIs) from enstatite (E) chondrites are similar to those of CAIs from other chondrite classes. CAIs from all chondrite classes formed under oxidizing conditions that are much different from the reducing conditions under which the E chondrites formed. Either CAIs formed at an earlier, more oxidizing epoch in the region where E chondrites ultimately formed, or they formed at a different place in the solar nebula and were transported into the E chondrite formation region. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Mineral Sci, Washington, DC 20560 USA. CALTECH, Div Geol & Planetary Sci 170 25, Lunat Asylum, Pasadena, CA 91125 USA. Arizona State Univ, Ctr Meteorite Studies, Tempe, AZ 85287 USA. Arizona State Univ, Dept Geol, Tempe, AZ 85287 USA. RP Guan, YB (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Mineral Sci, Washington, DC 20560 USA. RI WASSERBURG, GERALD /F-6247-2011 NR 21 TC 44 Z9 49 U1 0 U2 4 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD AUG 25 PY 2000 VL 289 IS 5483 BP 1330 EP 1333 DI 10.1126/science.289.5483.1330 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 347RF UT WOS:000088942400032 ER PT J AU Derevianko, A AF Derevianko, A TI Reconciliation of the measurement of parity nonconservation in Cs with the standard model SO PHYSICAL REVIEW LETTERS LA English DT Article ID ALKALI-METAL ATOMS; PERTURBATION-THEORY CALCULATIONS; HIGH-ACCURACY CALCULATION; ENERGY-LEVELS; ISOELECTRONIC SEQUENCE; MATRIX-ELEMENTS; CESIUM ATOM; HIGH ORDERS; TRANSITION; VIOLATION AB Contributions from the Breit interaction in atomic structure calculations account for 1.3 sigma of the previously reported 2.5 sigma deviation from the standard model in the Cs-133 weak charge [S.C. Bennett and C.E. Wieman, Phys. Rev. Lett. 82, 2484 (1999)]. The updated corrections for the neutron distribution reduce the discrepancy further to 1.0 sigma. The updated value of the weak charge is Q(W)(Cs-133) = - 72.65(28)(expt)(34)(theor). C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. RP Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. RI Derevianko, Andrei/G-8356-2011 NR 26 TC 106 Z9 108 U1 0 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 21 PY 2000 VL 85 IS 8 BP 1618 EP 1621 DI 10.1103/PhysRevLett.85.1618 PG 4 WC Physics, Multidisciplinary SC Physics GA 345ZT UT WOS:000088846100009 ER PT J AU Baker, MT van der Reyden, D Williams, DC AF Baker, MT van der Reyden, D Williams, DC TI Polymers in time capsules: A tutorial. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Chemon Int, Egypt MVE Mary Baker, Washington, DC 20036 USA. Smithsonian Inst, SCMRE, Washington, DC 20560 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 433-POLY BP U318 EP U318 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301832 ER PT J AU Blackman, MJ AF Blackman, MJ TI Tracing trade: Middle Eastern obsidian artifact and source analysis by INAA. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Smithsonian Inst, Smithsonian Ctr Mat Res & Educ, Gaithersburg, MD 20899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 149-NUCL BP U25 EP U25 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091300149 ER PT J AU Erhardt, D Tumosa, CS Mecklenburg, MF AF Erhardt, D Tumosa, CS Mecklenburg, MF TI Can artists' oil paints be accelerated aged? SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Smithsonian Inst, Smithsonian Ctr Mat Res & Educ, Suitland, MD 20746 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 452-POLY BP U321 EP U321 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301851 ER PT J AU Von Endt, DW AF Von Endt, DW TI Staying in shape: The stability of structural proteins in natural history museum storage fluids. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Smithsonian Inst, Smithsonian Ctr Mat Res & Educ, Suitland, MD 20746 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 454-POLY BP U321 EP U321 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301853 ER PT J AU Young, LA AF Young, LA TI Saving America's treasures: Threatened artifacts from the Apollo era. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Smithsonian Inst, Natl Air & Space Museum, Div Space Hist, Paul E Garber Facil, Suitland, MD 20746 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 20 PY 2000 VL 220 MA 435-POLY BP U319 EP U319 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 386XV UT WOS:000166091301834 ER PT J AU White, M Croft, RAC AF White, M Croft, RAC TI Suppressing linear power on dwarf galaxy halo scales SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : theory; large-scale structure of universe ID LY-ALPHA FOREST; COLD DARK-MATTER; N-BODY SIMULATIONS; INTERGALACTIC MEDIUM; MASS FLUCTUATIONS; EVOLUTION; SPECTRUM; UNIVERSE; MODEL AB Recently, it has been suggested that the dearth of small halos around the Milky Way arises because of a modification of the primordial power spectrum of fluctuations from inflation. Such modifications would be expected to alter the formation of structure from bottom-up to top-down on scales near where the short-scale power has been suppressed. Using cosmological simulations, we study the effects of such a modification of the initial power spectrum. While the halo multiplicity function depends primarily on the linear-theory power spectrum, most other probes of power are more sensitive to the nonlinear power spectrum. Collapse of large-scale structures as they go nonlinear regenerates a "tail" in the power spectrum, masking small-scale modifications to the primordial power spectrum except at very high z. Even the small-scale (k > 2 h Mpc(-1)) clustering of the Ly alpha forest is affected by this process, so that cold dark matter (CDM) models with sufficient power suppression to reduce the number of 10(10) M. halos by a factor of similar to 5 give similar Ly alpha forest power spectrum results. We conclude that other observations that depend more directly on the number density of collapsed objects, such as the number of damped Ly alpha systems or the redshift of reionization, may provide the most sensitive tests of these models. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP White, M (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI White, Martin/I-3880-2015; Croft, Rupert/N-8707-2014 OI White, Martin/0000-0001-9912-5070; Croft, Rupert/0000-0003-0697-2583 NR 49 TC 43 Z9 43 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP 497 EP 504 DI 10.1086/309273 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AY UT WOS:000089252600002 ER PT J AU Perna, R Raymond, J AF Perna, R Raymond, J TI Testing the multiple supernovae versus gamma-ray burst scenarios for giant HI supershells SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; ISM : bubbles; supernovae : general ID INTERSTELLAR-MEDIUM; MASSIVE STARS; EVOLUTION; REMNANT; MODELS; NOVA; GALAXIES; BUBBLES; ENERGY; PUPPIS AB The energy source of the giant H I supershells in nearby galaxies and in our own is still an unsettled issue. Proposed scenarios for production of near-complete ringlike supershells are multiple supernovae (SNe) and gamma-ray bursts (GRBs). In the late phase of evolution it is difficult to tell these models apart. We show that, if a supershell has been powered by multiple SNe, peculiar metal abundances should be found in the medium within the bubble. We present line diagnostics that could detect such unusual abundances, such as unusually high ratios of [O]/[Fe] and [Ne]/[Fe]. Among ions of the same element, a higher enhancement is expected in lines from a high-ionization state than in lines from a low-ionization state. Identification of the energy source of H I supershells would set strong constraints on the rates and energetics of GRBs, as well as on their location within a galaxy. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Perna, R (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 43 TC 17 Z9 18 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP 706 EP 711 DI 10.1086/309282 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AY UT WOS:000089252600018 ER PT J AU Girart, JM Estalella, R Ho, PTP Rudolph, AL AF Girart, JM Estalella, R Ho, PTP Rudolph, AL TI A multitransition HCO+ study in NGC 2264G: Anomalous emission of the J=1 -> 0 line SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (NGC 2264G); ISM : jets and outflows; ISM : molecules; radio lines : ISM; stars : formation ID HERBIG-HARO OBJECTS; OB1 MOLECULAR CLOUD; STAR-FORMING REGIONS; BIPOLAR OUTFLOW; DOWNSTREAM; CO; CS; HH-80-NORTH; EXCITATION; RADIATION AB We present multitransition observations of the HCO+ molecule toward the very young star-forming region associated with the NGC 22646 molecular outflow. Anomalous emission is observed in the lowest rotational transition; the J = 4 --> 3 and J = 3 --> 2 transitions clearly trace the dense core encompassing the exciting source of the molecular outflow, whereas the HCO+ J = 1 --> 0 is barely detected at a much lower intensity and has a much broader line shape. Analysis of the data strongly suggests that the HCO+ J = 1 --> 0 emission arising from the core is being absorbed efficiently by a cold low-density envelope around the core or a foreground cloud. This result seems exceptional, yet the J = 1 --> 0 HCO+ and HCN emission from other dense cores (especially those in giant molecular clouds) may be affected. In these cases, the rare isotopes of these molecules and higher rotational transitions of the main isotopes should be used to study these regions. Two quiescent clumps, JMG 99 G1 and G2, are detected in the blue lobe of the NGC 22646 molecular outflow, close to shock-excited near-IR H-2 knots. These clumps belong to the class of radiatively excited clumps, i.e., the radiation from the shock, evaporates the dust mantles and initiates a photochemical process, enhancing the emission of the HCO+. C1 Univ Illinois, Dept Astron, Urbana, IL 61801 USA. Univ Barcelona, Dept Astron & Meteorol, E-08028 Barcelona, Spain. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Harvey Mudd Coll, Dept Phys, Claremont, CA 91711 USA. RP Girart, JM (reprint author), Univ Illinois, Dept Astron, 1002 W Green St, Urbana, IL 61801 USA. RI Girart, Josep/O-1638-2014 OI Girart, Josep/0000-0002-3829-5591 NR 39 TC 24 Z9 24 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP 763 EP 774 DI 10.1086/309262 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AY UT WOS:000089252600025 ER PT J AU Latter, WB Dayal, A Bieging, JH Meakin, C Hora, JL Kelly, DM Tielens, AGGM AF Latter, WB Dayal, A Bieging, JH Meakin, C Hora, JL Kelly, DM Tielens, AGGM TI Revealing the photodissociation region: HST/NICMOS imaging of NGC 7027 SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : molecules; ISM : structure; molecular processes; planetary nebulae : general; planetary nebulae : individual (NGC 7027) ID PLANETARY-NEBULA NGC-7027; NEAR-INFRARED PROPERTIES; MOLECULAR-HYDROGEN; BIPOLAR NEBULAE; STARS; H-2; MORPHOLOGY; EVOLUTION; ENVELOPES; AFGL-2688 AB We report results from a Hubble Space Telescope (HST) and Near-Infrared Camera and Multiobject Spectrometer (NICMOS) program to study the distribution of hot neutral (molecular hydrogen) and ionized circumstellar material in the young planetary nebulae NGC 7027. HST/NICMOS provided very high spatial resolution imaging in line and continuum emission, and the stability and large dynamic range needed for investigating detailed structures in the circumstellar material. We present dramatic new images of NGC 7027 that have led to a new understanding of the structure in this important planetary nebula. The central star is clearly revealed, providing near-infrared fluxes that are used to directly determine the stellar temperature very accurately (T* = 198,000 K). It is found that the photodissociation layer as revealed by near-infrared molecular hydrogen emission is very thin (Delta R similar to 6 x 10(15) cm) and is biconical in shape. The interface region is structured and filamentary, suggesting the existence of hydrodynamic instabilities. We discuss evidence for the presence of one or more highly collimated, off-axis jets that might be present in NGC 7027. The NICMOS data are combined with earlier Hubble Space Telescope data to provide a complete picture of NGC 7027 using the highest spatial resolution data to date. The evolutionary future of NGC 7027 is discussed. C1 CALTECH, SIRTF Sci Ctr, IPAC, Pasadena, CA 91125 USA. Ctr Infrared Proc & Anal, Pasadena, CA USA. Jet Prop Lab, Pasadena, CA 91109 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Wyoming, Laramie, WY 82071 USA. Univ Groningen, Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands. RP Latter, WB (reprint author), CALTECH, SIRTF Sci Ctr, IPAC, MS 314-6, Pasadena, CA 91125 USA. EM latter@ipac.caltech.edu; adayal@ipac.caltech.edu; jbieging@as.arizona.edu; cmeakin@as.arizona.edu; jhora@cfa.harvard.edu; dkelly@as.arizona.edu; tielens@astro.rug.nl OI Hora, Joseph/0000-0002-5599-4650 NR 54 TC 63 Z9 63 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP 783 EP 797 DI 10.1086/309252 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AY UT WOS:000089252600027 ER PT J AU Narayan, R Igumenshchev, IV Abramowicz, MA AF Narayan, R Igumenshchev, IV Abramowicz, MA TI Self-similar accretion flows with convection SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; convection; hydrodynamics; turbulence ID ADVECTION-DOMINATED ACCRETION; BLACK-HOLES; DISKS; INSTABILITY; TRANSPORT; MODELS; STARS AB We consider height-integrated equations of an advection-dominated accretion flow (ADAF), assuming that there is no mass outflow. We include convection through a mixing-length formalism. We seek selfsimilar solutions in which the rotational velocity and sound speed scale as R-1/2, where R is the radius, and consider two limiting prescriptions for the transport of angular momentum by convection. In one limit, the transport occurs down the angular velocity gradient, so convection moves angular momentum outward. In the other, the transport is down the specific angular momentum gradient, so convection moves angular momentum inward. We also consider general prescriptions that lie in between the two limits. When convection moves angular momentum outward, we recover the usual self-similar solution for ADAFs in which the mass density scales as rho proportional to R-3/2. When convection moves angular momentum inward, the result depends on the viscosity coefficient alpha. If alpha > alpha(crit1) similar to 0.05, we once again find the standard ADAF solution. For alpha < alpha(crit2) similar to alpha(crit1), however, we find a nonaccreting solution in which rho proportional to R-1/2. We refer to this as a "convective envelope" solution or a "convection-dominated accretion flow." Two-dimensional numerical simulations of ADAFs with values of alpha less than or similar to 0.03 have been reported by several authors. The simulated ADAFs exhibit convection. By virtue of their axisymmetry, convection in these simulations moves angular momentum inward, as we confirm by computing the Reynolds stress. The simulations give rho proportional to R-1/2, in good agreement with the convective envelope solution. The R-1/2 density profile is not a consequence of mass outflow. The relevance of these axisymmetric low-alpha simulations to real accretion flows is uncertain. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Gothenburg, Inst Theoret Phys, S-41296 Gothenburg, Sweden. Chalmers Univ Technol, S-41296 Gothenburg, Sweden. RP Narayan, R (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 34 TC 259 Z9 262 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP 798 EP 808 DI 10.1086/309268 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AY UT WOS:000089252600028 ER PT J AU van Ballegooijen, AA Priest, ER Mackay, DH AF van Ballegooijen, AA Priest, ER Mackay, DH TI Mean field model for the formation of filament channels on the Sun SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; Sun : corona; Sun : magnetic fields ID MAGNETIC-FLUX TRANSPORT; SOLAR ATMOSPHERE; ACTIVE-REGION; QUIESCENT PROMINENCES; POLAR CROWN; RELAXATION; RECONNECTION; HELICITY; PATTERNS; SCALE AB The coronal magnetic field is subject to random footpoint motions that cause small-scale twisting and braiding of held lines. We present a mean field theory describing the effects of such small-scale twists on the large-scale coronal field. This theory assumes that the coronal field is force free, with electric currents flowing parallel or antiparallel to magnetic field lines. Random footpoint motions are described in terms of diffusion of the mean magnetic field at the photosphere. The appropriate mean field equations are derived, and a numerical method for solving these equations in three dimensions is presented. Preliminary results obtained with this method are also presented. In particular the formation of filament channels is studied. Filament channels are regions where the coronal magnetic field is strongly aligned with the underlying polarity inversion line in the photosphere. It is found that magnetic flux cancellation plays an important role in the formation of such channels. Various models of the coronal field are presented, including some in which the axial held is assumed to originate from below the photosphere. The models reproduce many of the observed features of filament channels, but the observed hemisphere pattern of dextral and sinistral channels remains a mystery. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ St Andrews, Dept Math & Computat Sci, St Andrews KY16 9SS, Fife, Scotland. RP van Ballegooijen, AA (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM vanballe@cfa.harvard.edu; eric@mcs.st-and.ac.uk OI van Ballegooijen, Adriaan/0000-0002-5622-3540 NR 60 TC 115 Z9 115 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP 983 EP 994 DI 10.1086/309265 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AY UT WOS:000089252600044 ER PT J AU Ashby, MLN Bergin, EA Plume, R Carpenter, JM Melnick, GJ Chin, G Erickson, NR Goldsmith, PF Harwit, M Howe, JE Kleiner, SC Koch, DG Neufeld, DA Patten, BM Schieder, R Snell, RL Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF AF Ashby, MLN Bergin, EA Plume, R Carpenter, JM Melnick, GJ Chin, G Erickson, NR Goldsmith, PF Harwit, M Howe, JE Kleiner, SC Koch, DG Neufeld, DA Patten, BM Schieder, R Snell, RL Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF TI Water abundance and velocity structure in S140, rho Oph A, and B335 SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; ISM : clouds; ISM : molecules; radio lines : ISM; stars : formation ID OPHIUCHI DARK CLOUD; STAR-FORMATION; VLA OBSERVATIONS; EMISSION; RATIO; H2O; PROTOSTAR; CLUSTER; REGIONS; CORE AB We present Monte Carlo radiative transfer models for B335, S140, and rho Ophiuchi A that simulate the emission line arising from the 557 GHz 1(10)-->1(01) ground-state transition of ortho-(H2O)-O-16. These models reproduce the line profiles with a combination of turbulent and macroscopic motions, and are consistent with gravitational infall in rho Oph A. We cannot, however, discriminate infall from outflow for S140. Our models are consistent with ortho-H2O abundances relative to H-2 of 2 x 10(-8) and 4.5 x 10(-9) in S140 and rho Oph A, respectively, and an upper limit of 4 x 10(-6) (3 sigma) in B335, assuming the ratio ortho-H-2/para-H-2 = 0.1. We quantify the impact of dust continuum emission on the derived abundances. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. Cornell Univ, Natl Astron & Ionosphere Ctr, Dept Astron, Ithaca, NY 14853 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany. RP Ashby, MLN (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Chin, Gordon/E-1520-2012; Goldsmith, Paul/H-3159-2016 NR 30 TC 25 Z9 25 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP L119 EP L122 DI 10.1086/312845 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AZ UT WOS:000089252700009 ER PT J AU Ashby, MLN Bergin, EA Plume, R Carpenter, JM Neufeld, DA Chin, G Erickson, NR Goldsmith, PF Harwit, M Howe, JE Kleiner, SC Koch, DG Patten, BM Schieder, R Snell, RL Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF Melnick, GJ AF Ashby, MLN Bergin, EA Plume, R Carpenter, JM Neufeld, DA Chin, G Erickson, NR Goldsmith, PF Harwit, M Howe, JE Kleiner, SC Koch, DG Patten, BM Schieder, R Snell, RL Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF Melnick, GJ TI An analysis of water line profiles in star formation regions observed by the Submillimeter Wave Astronomy Satellite SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : clouds; ISM : molecules; radio lines : ISM; stars : formation ID MOLECULAR CLOUD CORES; RADIATIVE-TRANSFER; EMISSION; H2O; CO; ABSORPTION; TEMPERATURE; EXCITATION; ORION; MODEL AB We present spectral line profiles for the 557 GHz 1(10)-->1(01) ground-state rotational transition of ortho-(H2O)-O-16 for 18 Galactic star formation regions observed by the Submillimeter Wave Astronomy Satellite. Water is unambiguously detected in every source. The line profiles exhibit a wide variety of shapes, including single-peaked spectra and self-reversed profiles. We interpret these profiles using a Monte Carlo code to model the radiative transport. The observed variations in the line profiles can be explained by variations in the relative strengths of the bulk flow and small-scale turbulent motions within the clouds. Bulk flow (infall, outflow) must be present in some cloud cores, and in certain cases this bulk flow dominates the turbulent motions. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. Cornell Univ, Natl Astron & Ionosphere Ctr, Dept Astron, Ithaca, NY 14853 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany. RP Ashby, MLN (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Chin, Gordon/E-1520-2012; Goldsmith, Paul/H-3159-2016 NR 33 TC 26 Z9 26 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP L115 EP L118 DI 10.1086/312842 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AZ UT WOS:000089252700008 ER PT J AU Bergin, EA Lellouch, E Harwit, M Gurwell, MA Melnick, GJ Ashby, MLN Chin, G Erickson, NR Goldsmith, PF Howe, JE Kleiner, SC Koch, DG Neufeld, DA Patten, BM Plume, R Schieder, R Snell, RL Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF AF Bergin, EA Lellouch, E Harwit, M Gurwell, MA Melnick, GJ Ashby, MLN Chin, G Erickson, NR Goldsmith, PF Howe, JE Kleiner, SC Koch, DG Neufeld, DA Patten, BM Plume, R Schieder, R Snell, RL Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF TI Submillimeter Wave Astronomy Satellite observations of Jupiter and Saturn: Detection of 557 GHz water emission from the upper atmosphere SO ASTROPHYSICAL JOURNAL LA English DT Article DE planets and satellites : individual (Jupiter, Saturn); radio continuum : solar system; radio lines : solar system; submillimeter ID GIANT PLANETS; TEMPERATURES; MILLIMETER; HYDROGEN; OXYGEN; VAPOR AB We have used the Submillimeter Wave Astronomy Satellite to carry out observations on Jupiter and Saturn in two bands centered at 489 and 553 GHz. We detect spectrally resolved 557 GHz H2O emission on both planets, constraining for the first time the residence levels of external water vapor in Jupiter's and Saturn's stratosphere. For both planets, the line appears to be formed at maximum pressures of about 5 mbar. For Jupiter, the data further show that water is not uniformly mixed but increases with altitude above the condensation level. In each planet, the amount of water implied by the data is 1.5-2.5 times larger than inferred from Infrared Space Observatory data. In addition, our observations provide new whole-disk brightness measurements of Jupiter and Saturn near 489 and 553 GHz. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Observ Paris, Dept Rech Spatiale, F-92195 Meudon, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Cornell Univ, Natl Astron & Ionosphere Ctr, Dept Astron, Ithaca, NY 14853 USA. Univ Massachusetts, Dept Astron, Amherst, MA 02133 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany. RP Bergin, EA (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Chin, Gordon/E-1520-2012; Goldsmith, Paul/H-3159-2016 NR 23 TC 30 Z9 30 U1 1 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP L147 EP L150 DI 10.1086/312846 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AZ UT WOS:000089252700015 ER PT J AU Bergin, EA Melnick, GJ Stauffer, JR Ashby, MLN Chin, G Erickson, NR Goldsmith, PF Harwit, M Howe, JE Kleiner, SC Koch, DG Neufeld, DA Patten, BM Plume, R Schieder, R Snell, RL Tolls, V Wang, Z Winnewisser, G Zhang, YF AF Bergin, EA Melnick, GJ Stauffer, JR Ashby, MLN Chin, G Erickson, NR Goldsmith, PF Harwit, M Howe, JE Kleiner, SC Koch, DG Neufeld, DA Patten, BM Plume, R Schieder, R Snell, RL Tolls, V Wang, Z Winnewisser, G Zhang, YF TI Implications of Submillimeter Wave Astronomy Satellite observations for interstellar chemistry and star formation SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; ISM : evolution; ISM : molecules; molecular processes; stars : formation ID DENSE MOLECULAR CLOUDS; CHEMICAL-MODELS; THERMAL BALANCE; GAS; EVOLUTION; DEPLETION; OXYGEN; ABUNDANCES; MECHANISM; CORES AB A long-standing prediction of steady state gas-phase chemical theory is that H2O and O-2 are important reservoirs of elemental oxygen and major coolants of the interstellar medium. Analysis of Submillimeter Wave Astronomy Satellite (SWAS) observations has set sensitive upper limits on the abundance of O-2 and has provided H2O abundances toward a variety of star-forming regions. Based on these results, we show that gaseous H2O and O-2 are not dominant carriers of elemental oxygen in molecular clouds. Instead, the available oxygen is presumably frozen on dust grains in the form of molecular ices, with a significant portion potentially remaining in atomic form, along with CO, in the gas phase. H2O and O-2 are also not significant coolants for quiescent molecular gas. In the case of H2O, a number of known chemical processes can locally elevate its abundance in regions with enhanced temperatures, such as warm regions surrounding young stars or in hot shocked gas. Thus, water can be a locally important coolant. The new information provided by SWAS, when combined with recent results from the Infrared Space Observatory, also provides several hard observational constraints for theoretical models of the chemistry in molecular clouds, and we discuss various models that satisfy these conditions. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. Cornell Univ, Natl Astron & Ionosphere Ctr, Dept Astron, Ithaca, NY 14853 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany. RP Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Chin, Gordon/E-1520-2012; Goldsmith, Paul/H-3159-2016 NR 48 TC 122 Z9 123 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP L129 EP L132 DI 10.1086/312843 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AZ UT WOS:000089252700011 ER PT J AU Goldsmith, PF Melnick, GJ Bergin, EA Howe, JE Snell, RL Neufeld, DA Harwit, M Ashby, MLN Patten, BM Kleiner, SC Plume, R Stauffer, JR Tolls, V Wang, Z Zhang, YF Erickson, NR Koch, DG Schieder, R Winnewisser, G Chin, G AF Goldsmith, PF Melnick, GJ Bergin, EA Howe, JE Snell, RL Neufeld, DA Harwit, M Ashby, MLN Patten, BM Kleiner, SC Plume, R Stauffer, JR Tolls, V Wang, Z Zhang, YF Erickson, NR Koch, DG Schieder, R Winnewisser, G Chin, G TI O-2 in interstellar molecular clouds SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : clouds; ISM : molecules ID INTER-STELLAR CLOUDS; GAS-PHASE CHEMISTRY; ROTATIONAL-EXCITATION; CARBON-MONOXIDE; UPPER LIMITS; ABUNDANCE; OXYGEN; SEARCH; RATIO; (OO)-O-16-O-18 AB We have used the Submillimeter Wave Astronomy Satellite (SWAS) to carry out deep integrations on the N-j = 3(3) --> 1(2) transition of O-2 in a variety of Galactic molecular clouds. We here report no convincing detection in an initial set of observations of 20 sources. We compare O-2 integrated intensities with those of (CO)-O-18 in a similarly sized beam and obtain 3 sigma upper limits for the O-2/(CO)-O-18 abundance ratio less than or equal to 2.3 in four clouds and less than or equal to 3.6 in five additional clouds. Our lowest individual limit corresponds to N(O-2)/N(H-2) < 2.6 x 10(-7) (3 sigma). A combination of data from nine sources yields < N(O-2)/N(H-2)> = [0.33 +/- 1.6 (3 sigma)] x 10(-7). These low limits, characterizing a variety of clouds in different environments at different Galactocentric radii, indicate that O-2 is not a major constituent of molecular clouds and is not an important coolant. The abundance of O-2 is significantly lower than predicted by steady state single-component chemical models. The present results are best understood in the context of cloud chemical and dynamical models that include the interaction of gas-phase molecules and grain surfaces and/or circulation of material between well-shielded and essentially unshielded regions. This circulation may be powered by turbulence or other driving forces that effectively keep molecular clouds chemically unevolved. C1 Cornell Univ, Natl Astron & Ionosphere Ctr, Dept Astron, Ithaca, NY 14853 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Goldsmith, PF (reprint author), Cornell Univ, Natl Astron & Ionosphere Ctr, Dept Astron, Space Sci Bldg, Ithaca, NY 14853 USA. RI Chin, Gordon/E-1520-2012; Goldsmith, Paul/H-3159-2016 NR 39 TC 89 Z9 90 U1 1 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP L123 EP L127 DI 10.1086/312854 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AZ UT WOS:000089252700010 ER PT J AU Gurwell, MA Bergin, EA Melnick, GJ Ashby, MLN Chin, G Erickson, NR Goldsmith, PF Harwit, M Howe, JE Kleiner, SC Koch, DG Neufeld, DA Patten, BM Plume, R Schieder, R Snell, RL Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF AF Gurwell, MA Bergin, EA Melnick, GJ Ashby, MLN Chin, G Erickson, NR Goldsmith, PF Harwit, M Howe, JE Kleiner, SC Koch, DG Neufeld, DA Patten, BM Plume, R Schieder, R Snell, RL Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF TI Submillimeter Wave Astronomy Satellite observations of the Martian atmosphere: Temperature and vertical distribution of water vapor SO ASTROPHYSICAL JOURNAL LA English DT Article DE planets and satellites : individual (Mars); radio lines : solar system; submillimeter ID MARS ATMOSPHERE; WAVELENGTHS; APHELION AB We report the first detections of absorption features in the submillimeter spectrum of Mars that are due to the H2O (1(10)-1(01)) and (CO)-C-13 (5-4) rotational transitions. Observations were obtained over several days near the planet's closest approach to Earth in 1999 April. These observations simultaneously provide us with an opportunity to derive the atmospheric temperature structure and to measure directly the distribution of water vapor with altitude. The Martian atmosphere is found to be relatively cool, consistent with results found from ground-based millimeter observations of CO. The distribution of water in the Martian atmosphere matches a profile of constant, 100% saturation from 10 to 45 km altitude. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. Cornell Univ, Natl Astron & Ionosphere Ctr, Dept Astron, Ithaca, NY 14853 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany. RP Gurwell, MA (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Chin, Gordon/E-1520-2012; Goldsmith, Paul/H-3159-2016 NR 20 TC 31 Z9 31 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP L143 EP L146 DI 10.1086/312857 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AZ UT WOS:000089252700014 ER PT J AU Howe, JE Ashby, MLN Bergin, EA Chin, G Erickson, NR Goldsmith, PF Harwit, M Hollenbach, DJ Kaufman, MJ Kleiner, SC Koch, DG Neufeld, DA Patten, BM Plume, R Schieder, R Snell, RL Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF Melnick, GJ AF Howe, JE Ashby, MLN Bergin, EA Chin, G Erickson, NR Goldsmith, PF Harwit, M Hollenbach, DJ Kaufman, MJ Kleiner, SC Koch, DG Neufeld, DA Patten, BM Plume, R Schieder, R Snell, RL Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF Melnick, GJ TI Extended [C I] and (CO)-C-13 (5 -> 4) emission in M17SW SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (M17SW); ISM : molecules; ISM : structure; radio lines : ISM submillimeter ID MOLECULAR CLOUDS; PHOTODISSOCIATION REGIONS; ATOMIC CARBON; CLUMPY STRUCTURE; LINE EMISSION; EXCITATION; MULTITRANSITION; SUBMILLIMETER; M17-SW; CORES AB We mapped a 13 x 22 pc region in emission from 492 GHz [C I] and, for the first time, 551 GHz (CO)-C-13 (5 --> 4) in the giant molecular cloud M17SW, The morphologies of the [C I] and (CO)-C-13 emission are strikingly similar The extent and intensity of the [C I] and (CO)-C-13 (5 --> 4) emission is explained as arising from photodissociation regions on the surfaces of embedded molecular clumps. Modeling of the (CO)-C-13 (5 --> 4) emission in comparison to (CO)-C-13 (1 --> 0) indicates a temperature gradient across the cloud, peaking to at least 63 K near the M17 ionization front and decreasing to at least 20 EC:at the western edge of the cloud. We see no correlation between gas density and column density, The beam-averaged column density of C I in the core is 1 x 10(18) cm(-2), and the mean column density ratio N(C I)/N(CO) is about 0.4; The variations of N(C I)/N(CO) with position in M17SW indicate a similar clump size distribution throughout the cloud. C1 Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Cornell Univ, Natl Astron & Ionosphere Ctr, Dept Astron, Ithaca, NY 14853 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. San Jose State Univ, Dept Phys, San Jose, CA 95192 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany. RP Howe, JE (reprint author), Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. RI Chin, Gordon/E-1520-2012; Goldsmith, Paul/H-3159-2016 NR 32 TC 15 Z9 15 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP L137 EP L141 DI 10.1086/312850 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AZ UT WOS:000089252700013 ER PT J AU Melnick, GJ Ashby, MLN Plume, R Bergin, EA Neufeld, DA Chin, G Erickson, NR Goldsmith, PE Harwit, M Howe, JE Kleiner, SC Koch, DG Patten, BM Schieder, R Snell, RL Stauffer, JR Tolls, V Wang, Z Winnewisser, C Zhang, YF AF Melnick, GJ Ashby, MLN Plume, R Bergin, EA Neufeld, DA Chin, G Erickson, NR Goldsmith, PE Harwit, M Howe, JE Kleiner, SC Koch, DG Patten, BM Schieder, R Snell, RL Stauffer, JR Tolls, V Wang, Z Winnewisser, C Zhang, YF TI Observations of water vapor toward Orion BN/KL SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; ISM : individual (Orion); ISM : molecules ID MOLECULAR CLOUD CORES; COLLISIONAL EXCITATION; SHOCKED REGIONS; THERMAL BALANCE; STAR FORMATION; ABUNDANCES; H2O; EMISSION; OUTFLOW; OMC-1 AB We have obtained spectra of the rotational ground-state 1(10)-1(01) 556.936 GHz ortho-(H2O)-O-16 and 1(10)-1(01) 547.676 GHz ortho-(H2O)-O-18 transitions toward Orion BN/KL using the Submillimeter Wave Astronomy Satellite (SWAS). The ortho-(H2O)-O-16 spectrum shows strong evidence for both a broad (Delta v similar or equal to 48 km s(-1)) and a narrow (Delta v similar or equal to 7.5 km s(-1)) component, while the ortho-(H2O)-O-18 shows evidence for only a broad (Delta v similar or equal to 24 km s(-1)) component. The broad component emission in both ortho-(H2O)-O-16 and ortho-(H2O)-O-18 arises primarily from gas heated within the low- and high-velocity outflows and shocked gas surrounding IRc2 in which the ortho-(H2O)-O-16 and ortho-(H2O)-O-18 fractional abundances are estimated to be 3.5 x 10(-4) and 7 x 10(-7), respectively. This finding provides further confirmation that water is efficiently and abundantly produced within warm shock-heated gas. We estimate that the hot core plus the compact ridge contribute less than or similar to 10% to the ortho-(H2O)-O-16 integrated intensity within the SWAS beam. The narrow component seen in the ortho-(H2O)-O-16 spectrum is best fitted by ortho-water emission from the extended ridge (ER) and the higher temperature core of the extended ridge (CER) with a common fractional abundance of 3.3 x 10(-8). The absence of any discernible narrow component in the ortho-(H2O)-O-18 spectrum is used to set 3 sigma upper limits on the ortho-water fractional abundance within the ER of 7 x 10(-8) and within the CER of 5.2 x 10(-7). This implies that within the dense extended quiescent region, gas-phase water is neither a major repository of oxygen nor a major coolant in Orion BN/KL. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. Cornell Univ, Dept Astron, Natl Astron & Ionosphere Ctr, Ithaca, NY 14853 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany. RP Melnick, GJ (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Chin, Gordon/E-1520-2012 NR 27 TC 43 Z9 43 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP L87 EP L91 DI 10.1086/312849 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AZ UT WOS:000089252700002 ER PT J AU Melnick, GJ Stauffer, JR Ashby, MLN Bergin, EA Chin, G Erickson, NR Goldsmith, PF Harwit, M Howe, JE Kleiner, SC Koch, DG Neufeld, DA Patten, BM Plume, R Schieder, R Snell, RL Tolls, V Wang, Z Winnewisser, G Zhang, YF AF Melnick, GJ Stauffer, JR Ashby, MLN Bergin, EA Chin, G Erickson, NR Goldsmith, PF Harwit, M Howe, JE Kleiner, SC Koch, DG Neufeld, DA Patten, BM Plume, R Schieder, R Snell, RL Tolls, V Wang, Z Winnewisser, G Zhang, YF TI The Submillimeter Wave Astronomy Satellite: Science objectives and instrument description SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : clouds; stars : formation; submillimeter ID C-I EMISSION; MOLECULAR CLOUDS; THERMAL BALANCE; ATOMIC OXYGEN; LINE; ABUNDANCE; ABSORPTION; CARBON AB The Submillimeter Wave Astronomy Satellite (SWAS), launched in 1998 December, is a NASA mission dedicated to the study of star formation through direct measurements of (1) molecular cloud composition and chemistry, (2) the cooling mechanisms that facilitate cloud collapse, and (3) the large-scale structure of the UV-illuminated cloud surfaces. To achieve these goals, SWAS is conducting pointed observations of dense [n(H-2) > 10(3) cm(-3)] molecular clouds throughout our Galaxy in either the ground state or a low-lying transition of five astrophysically important species: H2O, (H2O)-O-18, O-2, C I, and (CO)-C-13. By observing these lines SWAS is (1) testing long-standing theories that predict that these species are the dominant coolants of molecular clouds during the early stages of their collapse to form stars and planets and (2) supplying previously missing information about the abundance of key species central to the chemical models of dense interstellar gas. SI TIAS carries two independent Schottky barrier diode mixers - passively cooled to similar to 175 K - coupled to a 54 x 68 cm off-axis Cassegrain antenna with an aggregate surface error similar to 11 mu m rms. During its baseline 3 yr mission, SWAS is observing giant and dark cloud cores with the goal of detecting or setting an upper limit on the water and molecular oxygen abundance of 3 x 10(-6) (relative to H-2). In addition, advantage is being taken of SWAS's relatively large beam size of 3'.3 x 4'.5 at 553 GHz and 3'.5 x 5'.0 at 490 GHz to obtain large-area (similar to 1 degrees x 1 degrees) maps of giant and dark clouds in the (CO)-C-13 and C I lines. With the use of a 1.4 GHz bandwidth acousto-optical spectrometer, SWAS has the ability to simultaneously observe either the H2O, O-2, C I, and (CO)-C-13 lines or the (H2O)-O-18, O-2, and C I lines. All measurements are being conducted with a velocity resolution less than 1 km s(-1). C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Massachusetts, Five Coll Radio Astron Observ, Amherst, MA 01003 USA. Cornell Univ, Natl Astron & Ionosphere Ctr, Dept Astron, Ithaca, NY 14853 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany. RP Melnick, GJ (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Chin, Gordon/E-1520-2012; Goldsmith, Paul/H-3159-2016 NR 21 TC 130 Z9 132 U1 1 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP L77 EP L85 DI 10.1086/312856 PN 2 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AZ UT WOS:000089252700001 ER PT J AU Neufeld, DA Snell, RL Ashby, MLN Bergin, EA Chin, G Erickson, NR Goldsmith, PF Harwit, M Howe, JE Kleiner, SC Koch, DG Patten, BM Plume, R Schieder, R Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF Melnick, GJ AF Neufeld, DA Snell, RL Ashby, MLN Bergin, EA Chin, G Erickson, NR Goldsmith, PF Harwit, M Howe, JE Kleiner, SC Koch, DG Patten, BM Plume, R Schieder, R Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF Melnick, GJ TI Observations of interstellar water vapor in outflow regions SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; ISM : clouds; ISM : molecules ID L1157 DARK CLOUD; MOLECULAR CLOUDS; BIPOLAR OUTFLOW; HIGH-RESOLUTION; CO EMISSION; NGC-2071; FLOW; H2O; LINE; HYDROGEN AB We have observed the 1(10)-->1(01) transition of interstellar water vapor near 557 GHz toward the three outflow sources NGC 2071, L1157, and NGC 1333 IRAS 4 using the Submillimeter Wave Astronomy Satellite. In each case, the observations reveal broad emission from water in the outflow accompanied by a narrow absorption feature at the velocity of the quiescent gas. Our estimates of the average ortho-water abundance within the outflowing gas lie in the range (0.5-1.6) x 10(-6) relative to H-2. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Cornell Univ, Natl Astron & Ionosphere Ctr, Dept Astron, Ithaca, NY 14853 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany. RP Neufeld, DA (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA. RI Chin, Gordon/E-1520-2012; Goldsmith, Paul/H-3159-2016 NR 33 TC 31 Z9 31 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP L107 EP L110 DI 10.1086/312852 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AZ UT WOS:000089252700006 ER PT J AU Neufeld, DA Ashby, MLN Bergin, EA Chin, G Erickson, NR Goldsmith, PF Harwit, M Howe, JE Kleiner, SC Koch, DG Patten, BM Plume, R Schieder, R Snell, RL Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF Melnick, GJ AF Neufeld, DA Ashby, MLN Bergin, EA Chin, G Erickson, NR Goldsmith, PF Harwit, M Howe, JE Kleiner, SC Koch, DG Patten, BM Plume, R Schieder, R Snell, RL Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF Melnick, GJ TI Observations of absorption by water vapor toward Sagittarius B2 SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; ISM : clouds; ISM : individual (Sagittarius B2); ISM : molecules; radio lines : ISM ID MOLECULAR LINE SURVEY; STAR-FORMING REGIONS; GALACTIC-CENTER; SGR B2; CLOUDS; MULTILEVEL; AMMONIA; GALAXY AB We have observed the 1(10)-->1(01) pure rotational transitions of both (H2O)-O-16 and (H2O)-O-18 toward Sagittarius B2 using the Submillimeter Wave Astronomy Satellite. The spectra thereby obtained show a complex pattern of absorption and - in the case of (H2O)-O-16 - emission, with numerous features covering a wide range of LSR velocities (-130 to 130 km s(-1)) and representing absorption both in gas associated with Sgr B2 as well as by several components of foreground gas along the line of sight. The ortho-water abundance derived for the absorbing foreground gas is similar to 6 x 10(-7) relative to H-2. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. Cornell Univ, Natl Astron & Ionosphere Ctr, Dept Astron, Ithaca, NY 14853 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany. RP Neufeld, DA (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA. RI Chin, Gordon/E-1520-2012; Goldsmith, Paul/H-3159-2016 NR 23 TC 31 Z9 31 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP L111 EP L113 DI 10.1086/312853 PN 2 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AZ UT WOS:000089252700007 ER PT J AU Neufeld, DA Stauffer, JR Bergin, EA Kleiner, SC Patten, BM Wang, Z Ashby, MLN Chin, G Erickson, NR Goldsmith, PF Harwit, M Howe, JE Koch, DG Plume, R Schieder, R Snell, RL Tolls, V Winnewisser, G Zhang, YF Melnick, GJ AF Neufeld, DA Stauffer, JR Bergin, EA Kleiner, SC Patten, BM Wang, Z Ashby, MLN Chin, G Erickson, NR Goldsmith, PF Harwit, M Howe, JE Koch, DG Plume, R Schieder, R Snell, RL Tolls, V Winnewisser, G Zhang, YF Melnick, GJ TI Submillimeter Wave Astronomy Satellite observations of water vapor toward comet C/1999 H1 (Lee) SO ASTROPHYSICAL JOURNAL LA English DT Article DE comets : general; comets : individual (Lee (C/1999 HI)) AB We have detected the 1(10)-1(01) pure rotational transition of water vapor toward comet C/1999 H1 using the Submillimeter Wave Astronomy Satellite. Over the period 1999 May 19.01-23.69 UT, the average integrated antenna temperature was 1.79 +/- 0.03 K km s(-1) within a 3.'3 x 4.'5 (FWHM) elliptical beam. For an assumed ortho-to-para ratio of 3, we estimate the total water production rate as 8 x 10(28) s(-1). This value lies approximately 50% above the value estimated by Biver et al. from contemporaneous radio observations of hydroxyl molecules. The observed line width of 1.8 km s(-1) (FWHM) is broader than the instrumental profile and suggests an intrinsic line width of about 1.4 km s(-1) (FWHM). The data, taken during a portion of every 97 minute spacecraft orbit over a 4.68 day period, provide no evidence for variability. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. Cornell Univ, Natl Astron & Ionosphere Ctr, Dept Astron, Ithaca, NY 14853 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany. RP Neufeld, DA (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA. RI Chin, Gordon/E-1520-2012; Goldsmith, Paul/H-3159-2016 NR 16 TC 34 Z9 34 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP L151 EP L154 DI 10.1086/312851 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AZ UT WOS:000089252700016 ER PT J AU Plume, R Bensch, F Howe, JE Ashby, MLN Bergin, EA Chin, G Erickson, NR Goldsmith, PF Harwit, M Kleiner, S Koch, DG Neufeld, DA Patten, BM Schieder, R Snell, RL Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF Reynolds, K Joyce, R Tavoletti, C Jack, G Rodkey, CJ Melnick, GJ AF Plume, R Bensch, F Howe, JE Ashby, MLN Bergin, EA Chin, G Erickson, NR Goldsmith, PF Harwit, M Kleiner, S Koch, DG Neufeld, DA Patten, BM Schieder, R Snell, RL Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF Reynolds, K Joyce, R Tavoletti, C Jack, G Rodkey, CJ Melnick, GJ TI Large-scale (CO)-C-13 J=5 -> 4 and [C I] mapping Of Orion A SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; ISM : clouds; ISM : individual (Orion); ISM : molecules; stars : formation ID MOLECULAR CLOUD CORES; WARM GAS; EMISSION; SUBMILLIMETER; CARBON AB We present maps of the (CO)-C-13 J = 5 --> 4 (551 GHz) and [C I] P-3(1) --> P-3(0) (492 GHz) emission in the Orion A molecular cloud, covering a 0 degrees.5 x 2 degrees area. A large velocity gradient (LVG) analysis of (CO)-C-13 J = 5 --> 4 and J = 1 --> 0 suggests that the gas temperatures in the northern part of OMC-1. (north of Delta delta = -20') are similar to 45 K and are, on average, at least 20 K higher than those to the south. The average (CO)-C-13 column density is log (N/cm(-2)) = 16.4 +/- 0.3 and is fairly constant throughout the cloud, even in the low-temperature region south of BN/KL. LVG modeling of the [C I] emission shows a typical C-0 column density of 2 x 10(17) cm(-2), which yields a C/CO abundance ratio in the cloud of similar to 0.1 (rising to levels in excess of 0.5 at the cloud edges). Comparison of the Delta-variance (which measures spatial structure in a manner similar to a power spectrum) of the Submillimeter Wave Astronomy Satellite [C I], Five College Radio Astronomy Observatory (CO)-C-13 J = 1 --> 0, and CS J = 1 --> 0 velocity-integrated maps suggests that the [C I] and (CO)-C-13 emission arise from the same gas. In contrast, the CS emission likely originates in gas that is considerably more clumpy. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany. Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Cornell Univ, Dept Astron, Natl Astron & Ionosphere Ctr, Ithaca, NY 14853 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Keystone Oaks Planetarium, Pittsburgh, PA 15216 USA. RP Plume, R (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Chin, Gordon/E-1520-2012; Goldsmith, Paul/H-3159-2016 NR 24 TC 33 Z9 33 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP L133 EP L136 DI 10.1086/312847 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AZ UT WOS:000089252700012 ER PT J AU Snell, RL Howe, JE Ashby, MLN Bergin, EA Chin, G Erickson, NR Goldsmith, PF Harwit, M Kleiner, SC Koch, DG Neufeld, DA Patten, BM Plume, R Schieder, R Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF Melnick, GJ AF Snell, RL Howe, JE Ashby, MLN Bergin, EA Chin, G Erickson, NR Goldsmith, PF Harwit, M Kleiner, SC Koch, DG Neufeld, DA Patten, BM Plume, R Schieder, R Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF Melnick, GJ TI Water abundance in molecular cloud cores SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; ISM : clouds; ISM : molecules; radio lines : ISM ID HOT CORES; GL-2591; DENSITY; MODELS; H2O; CS AB We present Submillimeter Wave Astronomy Satellite (SWAS) observations of the 1(10)-->1(01) transition of ortho-H2O at 557 GHz toward 12 molecular cloud cores. The water emission was detected in NGC 7538, rho Oph A, NGC 2024, CRL 2591, W3, W3OH, Mon R2, and W33 and was not detected in TMC-1, L134N, and B335. We also present a small map of the H2O emission in S140. Observations of the (H2O)-O-18 line were obtained toward S140 and NGC 7538, but no emission was detected. The abundance of ortho-H2O relative to H-2 in the giant molecular cloud cores was found to vary between 6 x 10(-10) and 1 x 10(-8). Five of the cloud cores in our sample have previous H2O detections; however, in all cases the emission is thought to arise from hot cores with small angular extents. The H2O abundance estimated for the hot core gas is at least 100 times larger than in the gas probed by SI VAS. The most stringent upper limit on the ortho-H2O abundance in dark clouds is provided in TMC-I, where the 3 sigma upper limit on the ortho-H2O fractional abundance is 7 x 10(-8). C1 Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Cornell Univ, Natl Astron & Ionosphere Ctr, Dept Astron, Ithaca, NY 14853 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany. RP Snell, RL (reprint author), Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. RI Chin, Gordon/E-1520-2012; Goldsmith, Paul/H-3159-2016 NR 28 TC 112 Z9 112 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP L101 EP L105 DI 10.1086/312848 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AZ UT WOS:000089252700005 ER PT J AU Snell, RL Howe, JE Ashby, MLN Bergin, EA Chin, G Erickson, NR Goldsmith, PF Harwit, M Kleiner, SC Koch, DG Neufeld, DA Patten, BM Plume, R Schieder, R Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF Melnick, GJ AF Snell, RL Howe, JE Ashby, MLN Bergin, EA Chin, G Erickson, NR Goldsmith, PF Harwit, M Kleiner, SC Koch, DG Neufeld, DA Patten, BM Plume, R Schieder, R Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF Melnick, GJ TI Submillimeter Wave Astronomy Satellite observations of extended water emission in Orion SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; ISM : clouds; ISM : individual (Orion); ISM : molecules; radio lines : ISM ID MOLECULAR CLOUDS; SHOCKED REGIONS; VAPOR EMISSION; H2O; OMC-1; CORES AB We have used the Submillimeter Wave Astronomy Satellite to map the ground-state 1(10)-->1(01) transition of ortho-H2O at 557 GHz in the Orion molecular cloud. H2O emission was detected in Orion over an angular extent of about 20', or nearly 3 pc. The water emission is relatively weak, with line widths (3-6 km s(-1)) and V-LSR velocities (9-11 km s(-1)) consistent with an origin in the cold gas of the molecular ridge. We find that the ortho-H2O abundance relative to H-2 in the extended gas in Orion varies between 1 and 8 x 10(-8), with an average of 3 x 10(-8). The absence of detectable narrow-line ortho-(H2O)-O-18 emission is used to set a 3 sigma upper limit on the relative ortho-H2O abundance of 7 x 10(-8). C1 Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Cornell Univ, Natl Astron & Ionosphere Ctr, Dept Astron, Ithaca, NY 14853 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany. RP Snell, RL (reprint author), Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. RI Chin, Gordon/E-1520-2012; Goldsmith, Paul/H-3159-2016 NR 25 TC 50 Z9 50 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP L93 EP L96 DI 10.1086/312855 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AZ UT WOS:000089252700003 ER PT J AU Snell, RL Howe, JE Ashby, MLN Bergin, EA Chin, G Erickson, NR Goldsmith, PF Harwit, M Kleiner, SC Koch, DG Neufeld, DA Patten, BM Plume, R Schieder, R Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF Melnick, GJ AF Snell, RL Howe, JE Ashby, MLN Bergin, EA Chin, G Erickson, NR Goldsmith, PF Harwit, M Kleiner, SC Koch, DG Neufeld, DA Patten, BM Plume, R Schieder, R Stauffer, JR Tolls, V Wang, Z Winnewisser, G Zhang, YF Melnick, GJ TI The distribution of water emission in M17SW SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; ISM : clouds; ISM : molecules; radio lines : ISM ID MOLECULAR CLOUDS; CLUMPY STRUCTURE; ATOMIC CARBON; CS; MULTITRANSITION; SUBMILLIMETER; CORES; H2O; SW; CO AB We present a 17-point map of the M17SW cloud core in the 1(10)-->1(01) transition of ortho-H2O at 557 GHz obtained with Submillimeter Wave Astronomy Satellite. Water emission was detected in 11 of the 17 observed positions. The line widths of the H2O emission vary between 4 and 9 km s(-1) and are similar to other emission lines that arise in the M17SW core. A direct comparison is made between the spatial extent of the H2O emission and the (CO)-C-13 J = 5-->4 emission; the good agreement suggests that the H2O emission arises in the same warm, dense gas as the (CO)-C-13 emission. A spectrum of the (H2O)-O-18 line was also obtained at the center position of the cloud core, but no emission was detected. We estimate that the average abundance of ortho-H2O relative to H-2 within the M17 dense core is approximately 1 x 10(-9), 30 times smaller than the average for the Orion core. Toward the I-I Il region/molecular cloud interface in M17SW the ortho-H2O abundance may be about 5 times larger than in the dense core. C1 Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Cornell Univ, Natl Astron & Ionosphere Ctr, Dept Astron, Ithaca, NY 14853 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany. RP Snell, RL (reprint author), Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. RI Chin, Gordon/E-1520-2012; Goldsmith, Paul/H-3159-2016 NR 21 TC 24 Z9 24 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2000 VL 539 IS 2 BP L97 EP L100 DI 10.1086/312844 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353AZ UT WOS:000089252700004 ER PT J AU Wickliffe, ME Lawler, JE Nave, G AF Wickliffe, ME Lawler, JE Nave, G TI Atomic transition probabilities for DyI and DyII SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID ARGON BRANCHING RATIOS; OSCILLATOR-STRENGTHS; LIFETIME MEASUREMENTS; SOLAR SPECTRUM; DYSPROSIUM; SPECTROMETER; CALIBRATION AB Atomic transition probabilities for 915 spectral lines of neutral and singly ionized dysprosium are reported. Typical uncertainties are less than or equal to +/-10%. Branching fractions, measured using the 1.0 m Fourier transform spectrometer (FTS) at the National Solar Observatory and the 2.0 m FTS at the National Institute of Standards and Technology (NIST), are combined with recently published radiative lifetimes, measured using time-resolved laser-induced fluorescence on a slow atomic/ionic be;lm, to determine these transition probabilities. Reference sets of Ar I and ArII branching ratios are used in most of the work reported here to establish a radiometric calibration for the Fourier transform spectral from the National Solar Observatory. A subset of the lines are also measured using the NIST FTS. Most importantly, an independent radiometric calibration based on standard lamps is used with the NIST FTS. The generally good agreement between these independent measurements provides additional confidence in the radiometric calibration and the accuracy of the measurements. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Lawler, JE (reprint author), Univ Wisconsin, Dept Phys, 1150 Univ Ave, Madison, WI 53706 USA. NR 28 TC 94 Z9 94 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD AUG 15 PY 2000 VL 66 IS 4 BP 363 EP 404 DI 10.1016/S0022-4073(99)00173-9 PG 42 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 315AZ UT WOS:000087091600004 ER PT J AU Gingerich, O AF Gingerich, O TI June 8, 2004 - Venus in transit SO TLS-THE TIMES LITERARY SUPPLEMENT LA English DT Book Review C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Gingerich, O (reprint author), Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU TIMES SUPPLEMENTS LIMITED PI MARKET HARBOROUGH PA TOWER HOUSE, SOVEREIGN PARK, MARKET HARBOROUGH LE87 4JJ, ENGLAND SN 0307-661X J9 TLS-TIMES LIT SUPPL JI TLS-Times Lit. Suppl. PD AUG 11 PY 2000 IS 5080 BP 29 EP 29 PG 1 WC Humanities, Multidisciplinary SC Arts & Humanities - Other Topics GA 344NP UT WOS:000088766000053 ER PT J AU Barkana, R Loeb, A AF Barkana, R Loeb, A TI Identifying the reionization redshift from the cosmic star formation rate SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : theory; galaxies : formation ID GUNN-PETERSON TROUGH; INTERGALACTIC MEDIUM; HIERARCHICAL-MODELS; GALAXY FORMATION; DWARF GALAXIES; CLUSTERS; UNIVERSE AB We show that the cosmic star formation rate per comoving volume should exhibit a distinct drop around the reionization redshift, when the H II regions in the intergalactic medium around individual ionizing sources first overlapped The drop results from the increase in the temperature of the intergalactic medium as it was photoionized, and the consequent suppression of the formation of low-mass galaxies. We show quantitatively that the detection of this drop, which is marked by a corresponding fall in the number counts of faint galaxies, should become feasible over the coming decade with the Next Generation Space Telescope. C1 Inst Adv Study, Princeton, NJ 08540 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Barkana, R (reprint author), Inst Adv Study, Olden Lane, Princeton, NJ 08540 USA. EM barkana@ias.edu; aloeb@cfa.harvard.edu NR 45 TC 62 Z9 62 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2000 VL 539 IS 1 BP 20 EP 25 DI 10.1086/309229 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347RQ UT WOS:000088943300003 ER PT J AU Grego, L Carlstrom, JE Joy, MK Reese, ED Holder, GP Patel, S Cooray, AR Holzapfel, WL AF Grego, L Carlstrom, JE Joy, MK Reese, ED Holder, GP Patel, S Cooray, AR Holzapfel, WL TI The Sunyaev-Zeldovich effect in Abell 370 SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; cosmology : observations; galaxies : clusters : individual (Abell 370); techniques : interferometric ID X-RAY; INTRACLUSTER GAS; GALAXY CLUSTERS; DEUTERIUM; EMISSION; STATE AB We present interferometric measurements of the Sunyaev-Zeldovich (SZ) effect toward the galaxy cluster Abell 370. These measurements, which directly probe the pressure of the cluster's gas, show the gas distribution to be strongly aspherical, as do the X-ray and gravitational lensing observations. We calculate the cluster's gas mass fraction in two ways. We first compare the gas mass derived from the SZ measurements to the lensing-derived gravitational mass near the critical lensing radius. We also calculate the gas mass fraction from the SZ data by deprojecting the three-dimensional gas density distribution and deriving the total mass under the assumption that the gas is in hydrostatic equilibrium (HSE). We test the assumptions in the HSE method by comparing the total cluster mass implied by the two methods and find that they agree within the errors of the measurement. We discuss the possible systematic errors in the gas mass fraction measurement and the constraints it places on the matter density parameter, Omega(M). C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. Univ Alabama, Dept Astron, Huntsville, AL 35899 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Grego, L (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Holzapfel, William/I-4836-2015 NR 45 TC 37 Z9 37 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2000 VL 539 IS 1 BP 39 EP 51 DI 10.1086/309190 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347RQ UT WOS:000088943300005 ER PT J AU Holzapfel, WL Carlstrom, JE Grego, L Holder, G Joy, M Reese, ED AF Holzapfel, WL Carlstrom, JE Grego, L Holder, G Joy, M Reese, ED TI Limits on arcminute-scale cosmic microwave background anisotropy at 28.5 GHz SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; cosmology : observations ID GALACTIC EMISSION; POWER SPECTRUM; RADIO-SOURCES; RADIATION; FLUCTUATIONS; REIONIZATION; SEARCH; CMB; CLUSTERS; GALAXIES AB We have used the Berkeley-Illinois-Maryland Association (BIMA) millimeter array outfitted with sensitive centimeter-wave receivers to search for cosmic microwave background (CMB) anisotropies on arcminute scales. The interferometer was placed in a compact configuration that produces high brightness sensitivity, while providing discrimination against point sources. Operating at a frequency of 28.5 GHz, the FWHM primary beam of the instrument is similar to 6'.6. We have made sensitive images of seven fields, four of which where chosen specifically to have low IR dust contrast and to be free of bright radio sources. Additional observations with the Owens Valley Radio Observatory (OVRO) millimeter array were used to assist in the location and removal of radio point sources. Applying a Bayesian analysis to the raw visibility data, we place limits on CMB anisotropy flat-band power of Q(flat) = 5.6(-5.6)(+3.0) mu K and Q(flat) < 14.1 mu K at 68% and 95% confidence, respectively. The sensitivity of this experiment to flat-band power peaks at a multipole of l = 5470, which corresponds to an angular scale of similar to 2'. The most likely value of Q(flat) is similar to the level of the expected secondary anisotropies. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. RP Holzapfel, WL (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI Holzapfel, William/I-4836-2015 NR 45 TC 18 Z9 18 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2000 VL 539 IS 1 BP 57 EP 66 DI 10.1086/309211 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347RQ UT WOS:000088943300007 ER PT J AU Holzapfel, WL Carlstrom, JE Grego, L Joy, M Reese, ED AF Holzapfel, WL Carlstrom, JE Grego, L Joy, M Reese, ED TI Investigation of two reported arcminute-scale microwave decrements at 28.5 GHz SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; cosmology : observations; galaxies : clusters : general; techniques : interferometric AB The Ryle telescope has been used at a frequency of 15 GHz, to detect a flux decrement in the direction of the quasar pair PC 1643 +4631A, B. This signal was interpreted as the Sunyaev-Zeldovich effect (SZE) produced by a distant cluster of galaxies. In the course of an effort to measure cosmic microwave background (CMB) anisotropies with a deep pointing of the VLA at 8.4 GHz, a second group detected a similar, but smaller, decrement. They also proposed that this signal might be explained as the SZE signal produced by a distant galaxy cluster. We report observations with the Berkeley-Illinois-Maryland Association (BIMA) interferometer operating at 28.5 GHz, in which we find no evidence for a SZE signal in the direction of either of the proposed clusters. In the case of the Ryle detection, the BIMA data are inconsistent with the SZE model proposed to explain the observed decrement at greater than 99.99% confidence. Together with published X-ray and optical searches, these results make a compelling case against the interpretation of the Ryle decrement as being due to the SZE in a massive cluster of galaxies. For the smaller VLA source, the BIR IA observations are not as constraining. The BIMA data are inconsistent with the proposed SZE model at greater than 90% confidence. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Chicago, Dept Astron, Chicago, IL 60637 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. RP Holzapfel, WL (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI Holzapfel, William/I-4836-2015 NR 18 TC 5 Z9 5 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2000 VL 539 IS 1 BP 67 EP 72 DI 10.1086/309210 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347RQ UT WOS:000088943300008 ER PT J AU Panagia, N Romaniello, M Scuderi, S Kirshner, RP AF Panagia, N Romaniello, M Scuderi, S Kirshner, RP TI Young stellar populations around SN 1987A SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (Large Magellanic Cloud); Magellanic Clouds; stars : early-type; stars : evolution; stars : pre-main-sequence; supernovae : individual (SN 1987A) ID LARGE MAGELLANIC CLOUD; MAIN-SEQUENCE STARS; PHOTOMETRY; CLUSTERS; SN-1987A; RING; LMC AB We present the first results of a study of the stellar population in a region of 30 pc radius around SN 1987A, based on an ana ysis of multiband Hubble Space Telescope (HST) WFPC2 images. The effective temperature, radius and, possibly, reddening of each star were determined by fitting the measured broadband magnitudes to the ones calculated with model atmospheres. In particular, we have determined effective temperatures and bolometric luminosities for 21,995 stars, and for a subsample of 2510 stars we also determined individual reddening corrections. In addition, we have identified all stars with Ha equivalent widths in excess of 8 Angstrom a total of 492 stars. An inspection of the H-R diagram reveals the presence of several generations of young stars, with ages between 1 and 150 Myr, superposed on a much older field population (0.6-6 Gyr). A substantial fraction of young stars with ages around 12 Myr make up the stellar generation coeval to SN 1987A progenitor. The youngest stars in the held appear to be strong-line T Tauri stars, identified an the basis of their conspicuous (W-eq > 8 Angstrom) H alpha excesses. This constitute the first positive detection of low-mass (about 1-2 M.) pre-mam-sequence (PMS) stars outside the Milky Way. Their positions in the H-R diagram appear to require that star formation in the LMC occurs with accretion rates about 10 times higher than in the Milky Way, i.e., similar to 10(-4) M. yr(-1). SN 1987A appears to belong to a loose, young cluster 12 +/- 2 Myr old, in which the slope of the present mass function is almost identical to Salpeter's, i.e., Gamma = d log N/d log M similar or equal to - 1.25 for masses above 3 M., but becomes much Batter for lower masses, i.e., Gamma similar or equal to -0.5. On a large scale, we find that the spatial distributions of massive r tars and low-mass PMS stars are conclusively different, indicating that different star formation processes operate for high- and low-mass stars. This results casts doubts on the validity of an initial mass function (IMF) concept on a small scale (say, less than 10 pc). Moreover, it appears that a determination of the low-mass end IMF in the LMC requires an explicit identification of PMS stars. A preliminary analysis, done for the whole held as a single entity, shows that the IMF slope for the young population present over :he entire region is steeper than Gamma similar or equal to -1.7. C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA. European So Observ, D-85748 Garching, Germany. Osservatorio Astrofis Catania, I-95125 Catania, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Panagia, N (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. NR 36 TC 47 Z9 47 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2000 VL 539 IS 1 BP 197 EP 208 DI 10.1086/309212 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347RQ UT WOS:000088943300023 ER PT J AU LeBohec, S Bond, IH Bradbury, SM Buckley, JH Burdett, AM Carter-Lewis, DA Catanese, M Cawley, MF Dunlea, S D'Vali, M Fegan, DJ Fegan, SJ Finley, JP Gaidos, JA Hall, TA Hillas, AM Horan, D Knapp, J Krennrich, F Lessard, RW Macomb, D Masterson, C Quinn, J Rose, HJ Samuelson, FW Sembroski, GH Vassiliev, VV Weekes, TC AF LeBohec, S Bond, IH Bradbury, SM Buckley, JH Burdett, AM Carter-Lewis, DA Catanese, M Cawley, MF Dunlea, S D'Vali, M Fegan, DJ Fegan, SJ Finley, JP Gaidos, JA Hall, TA Hillas, AM Horan, D Knapp, J Krennrich, F Lessard, RW Macomb, D Masterson, C Quinn, J Rose, HJ Samuelson, FW Sembroski, GH Vassiliev, VV Weekes, TC TI Gamma-ray observations of the galactic plane at energies E > 500 GeV SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic rays; diffuse radiation; gamma rays : observations ID SATELLITE; TELESCOPE; TEV AB In 1998 and 1999 the Whipple Observatory 10 m telescope was used to search for diffuse gamma-ray emission from the Galactic plane. At this time, the telescope was equipped with a large (4"8) held of view camera, well suited to detect diffuse gamma-ray emission. No significant evidence of emission was found. Assuming the TeV emission profile matches EGRET observations above 1 GeV with a differential spectral index of 2.4, we derive an upper limit of 3.0 x 10(-8) cm(-2) s(-1) sr(-1) for the average diffuse emission above 500 GeV in the Galactic latitude range from -2 degrees to +2 degrees at Galactic longitude 40 degrees. Comparisons with EGRET observations provide a lower limit of 2.31 for the differential spectral index of the diffuse emission, assuming there is no break in the spectrum between 30 and 500 GeV. This constrains models for diffuse emission with a significant inverse Compton contribution. C1 Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Univ Leeds, Dept Phys, Leeds LS2 9JT, W Yorkshire, England. Washington Univ, Dept Phys, St Louis, MO 63130 USA. Harvard Smithsonian Ctr Astrophys, Fred Lawrence Whipple Observ, Amado, AZ 85645 USA. St Patricks Coll, Dept Phys, Maynooth, Kildare, Ireland. Univ Coll Dublin, Dept Phys, Dublin 4, Ireland. Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Space Res Assoc, Lanham, MD USA. RP LeBohec, S (reprint author), Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. OI Knapp, Johannes/0000-0003-1519-1383 NR 25 TC 41 Z9 42 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2000 VL 539 IS 1 BP 209 EP 215 DI 10.1086/309227 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347RQ UT WOS:000088943300024 ER PT J AU Beckert, T AF Beckert, T TI Advection-dominated accretion with infall and outflows SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; Galaxy : center; hydrodynamics ID SAGITTARIUS-A-ASTERISK; BLACK-HOLES; NGC-4258; DISKS; FLOWS; CONSTRAINTS AB We present self-similar solutions for advection-dominated accretion flows with radial viscous force in the presence of outflows from the accretion flow or infall. The axisymmetric how is treated in variables integrated over polar sections and the effects of infall and outflows on the accretion flow are parametrized for possible configurations compatible with the self-similar solution. We investigate the resulting accretion hows for three different viscosity laws and derive upper limits on the viscosity parameter alpha. In addition, we find a natural connection to nonrotating and spherical accretion with turbulent viscosity, which is assumed to persist even without differential rotation. Positive Bernoulli numbers for advection-dominated accretion allow a fraction of the gas to be expelled in an outflow, and the upper limit on the viscosity predicts that outflows are inevitable for equations of state close to an ideal gas. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Max Planck Inst Radioastron, D-53121 Bonn, Germany. RP Beckert, T (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 27 TC 13 Z9 13 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2000 VL 539 IS 1 BP 223 EP 234 DI 10.1086/309219 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347RQ UT WOS:000088943300026 ER PT J AU Kaghashvili, EK Esser, R AF Kaghashvili, EK Esser, R TI Velocity shear-induced mode conversion in solar wind and streamer plasmas SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; solar wind; Sun : corona; waves ID POLAR CORONAL HOLE; ALFVEN WAVES; CYCLOTRON-RESONANCE; PHYSICAL-PROPERTIES; WHITE-LIGHT; ACCELERATION; CONSTRAINTS; UVCS/SOHO; REGION; FLOWS AB The possible scenario of Alfven wave transformation into other MHD waves due to inhomogeneous flow in different regions of solar wind/corona is examined. We have chosen four examples with different plasma parameters and velocity shear parameters as representative cases for the plasma conditions. Two of the cases are representative of coronal holes and streamers at a radial distance of 1.6 Ro. The third example examines the effect of an increased velocity shear due to the vicinity of a boundary. The fourth case represents solar wind conditions at 1 AU, where the plasma parameter is about unity. To study the wave coupling in the above described cases, we make use of "nonmodal" formalism, which appears to be a useful tool for wave processes taking place in a plasma with velocity shear. Our finding is that the possibility of coupling between Alfven waves and fast magnetosonic waves exists in coronal holes while for streamer conditions the Alfven mode couples to the slow magnetosonic mode. In the inner corona, it seems that these two possible ways of coupling do not overlap each other in the same structures but beyond the Alfvenic point, where beta is close to unity, both of them can operate at the same time and the mechanism is more sensitive to the background plasma conditions. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Kaghashvili, EK (reprint author), Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. NR 45 TC 13 Z9 14 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2000 VL 539 IS 1 BP 463 EP 468 DI 10.1086/309233 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347RQ UT WOS:000088943300047 ER PT J AU Canizares, CR Huenemoerder, DP Davis, DS Dewey, D Flanagan, KA Houck, J Markert, TH Marshall, HL Schattenburg, ML Schulz, NS Wise, M Drake, JJ Brickhouse, NS AF Canizares, CR Huenemoerder, DP Davis, DS Dewey, D Flanagan, KA Houck, J Markert, TH Marshall, HL Schattenburg, ML Schulz, NS Wise, M Drake, JJ Brickhouse, NS TI High-resolution X-ray spectra of Capella: Initial results from the Chandra High-Energy Transmission Grating Spectrometer SO ASTROPHYSICAL JOURNAL LA English DT Article DE instrumentation : spectrographs; stars : coronae; stars : individual (Capella); X-rays : general; X-rays : stars ID CANUM-VENATICORUM BINARIES; CORONAL STRUCTURE; EUV SPECTROSCOPY; COOL STARS; EMISSION; LINES AB High-resolution spectra of the active binary Capella (G8 III + G1 III) covering the energy range of 0.4-8.0 keV (1.5-30 Angstrom) show a large number of emission lines, demonstrating the performance of the High-Energy Transmission Crating Spectrometer. A preliminary application of plasma diagnostics provides information on coronal temperatures and densities. Lines arising from different elements in a range of ionization states indicate that Capella has plasma with a broad range of temperatures, from log T = 6.3 to 7.2, generally consistent with recent results from observations with the Extreme-Ultraviolet Explorer and the Advanced Satellite for Cosmology and Astrophysics. The electron density is determined from He-like O VII lines, giving the value of Ne similar to 10(10) cm(-3) at T-e similar to 2 x 10(6) K; He-like lines formed at higher temperatures give only upper limits to the electron density. The density and emission measure from O VII lines together indicate that the coronal loops are significantly smaller than the stellar radius. C1 MIT, Space Res Ctr, Cambridge, MA 02139 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Canizares, CR (reprint author), MIT, Space Res Ctr, 70 Vassar St, Cambridge, MA 02139 USA. NR 23 TC 162 Z9 164 U1 1 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 2000 VL 539 IS 1 BP L41 EP L44 DI 10.1086/312823 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347RU UT WOS:000088943600011 ER PT J AU Zusi, RL Livezey, BC AF Zusi, RL Livezey, BC TI Homology and phylogenetic implications of some enigmatic cranial features in Galliform and Anseriform birds SO ANNALS OF CARNEGIE MUSEUM LA English DT Review DE Anseriformes; cranium; Galliformes; homology; myology; osteology; processus postorbitalis; processus zygomaticus ID MORPHOLOGICAL CHARACTERS; GEOMETRIC MORPHOMETRICS; MULTISTATE CHARACTERS; ONTOGENIC CRITERION; DUCKS ANATIDAE; DOMESTIC-FOWL; PARTIAL WARPS; AVIAN SKULL; SYSTEMATICS; EVOLUTION AB Two landmarks of the temporal region of the skull in most birds are the zygomatic process (processus zygomaticus) and the postorbital process (processus postorbitalis). The morphology and homology of these processes in gallinaceous birds (Galliformes) and waterfowl (Anseriformes), however, are not clear. Anseriformes usually are said to lack a processus zygomaticus. By contrast, the processus zygomaticus of many Galliformes often is described as connected to the tip of the processus postorbitalis, forming a temporal arch. Olson and Feduccia (1980a) cited these cranial differences as evidence opposing a hypothesis of sister relationship between the two orders, an hypothesis having a substantial history of advocacy (Seebohm, 1889; Shufeldt, 1901; Delacour, 1954; Johnsgard, 1965; Cracraft, 1981a, 1986; Schulin, 1987). Dzerzhinsky (1982, 1995) contradicted the proposal by Olson and Feduccia (1980a), interpreting the two processes as completely fused in Anseriformes, forming a unique "sphenotemporal process," which he averred to have been derived evolutionarily from the condition found in the Galliformes. In the present study, we examined skulls and jaw muscles of juvenile and adult specimens of selected taxa from both orders to test these opposing hypotheses, and found that: (a) the processus zygomaticus is small or lacking in adult Galliformes, and absent in all Anseriformes; (b) the processus zygomaticus is connected to the tip of the processus postorbitalis by an ossified aponeurosis of m. adductor mandibulae externus (aponeurosis zygomatica) in adults of most galliforms, whereas the aponeurosis zygomatica of anseriforms has a linear origin along the os squamosum as far as the processus postorbitalis; the aponeurosis zygomatica is ossified in Anhimidae and unossified in Anatidae; (c) a laterally exposed fossa of the temporal region (fossa musculorum temporalium) is reduced in Galliformes and absent in Anseriformes; (d) pars superficialis and pars zygomatica of in. adductor mandibulae externus are shifted rostrad in Galliformes and Anseriformes, and (e) pars articularis of m. adductor mandibulae externus is much enlarged in both orders. Based on these observations, we conclude that the parts of musculus adductor mandibulae externus of Anseriformes have been misinterpreted in a number of previous studies, perhaps reflecting confusion about associated processes and fossae. These findings are interpreted with respect to the homology of the osteological features and their associated muscles. The distribution of the included states supports the growing consensus for a sister relationship between the Galliformes and Anseriformes. C1 Smithsonian Inst, Museum Natl Hist Nat, Div Birds, Sect Birds, Washington, DC 20560 USA. RP Zusi, RL (reprint author), Smithsonian Inst, Museum Natl Hist Nat, Div Birds, Sect Birds, Washington, DC 20560 USA. NR 232 TC 26 Z9 31 U1 1 U2 2 PU CARNEGIE MUSEUM NATURAL HISTORY PI PITTSBURGH PA 4400 FORBES AVE, PITTSBURGH, PA 15213 USA SN 0097-4463 J9 ANN CARNEGIE MUS JI Ann. Carnegie Mus. PD AUG 9 PY 2000 VL 69 IS 3 BP 157 EP 193 PG 37 WC Paleontology; Zoology SC Paleontology; Zoology GA 609NB UT WOS:000178910900002 ER PT J AU Perdices, A Doadrio, I Cote, IM Machordom, A Economidis, P Reynolds, JD AF Perdices, A Doadrio, I Cote, IM Machordom, A Economidis, P Reynolds, JD TI Genetic divergence and origin of Mediterranean populations of the River Blenny Salaria fluviatilis (Teleostei : Blenniidae) SO COPEIA LA English DT Article ID FRESH-WATER AB The current distribution of the River Blenny Salaria (= Blennius) fluviatilis, one of the two freshwater representatives of a large, cosmopolitan marine fish family, poses an interesting biogeographical problem because this species inhabits widely separate circum-Mediterranean watersheds. Potential scenarios of its dispersal were examined using allozyme analysis of several populations from the Iberian and Greek peninsulas. Based on Nei genetic distances, the most divergent populations were the populations inhabiting lakes, Lake Trichonis in Greece, and Ruidera Lakes in Spain. Their high divergence suggests their early isolation from the main ingroup populations. In contrast, low genetic distances were found among river populations regardless of geographic location. There was a correlation between genetic distance and geographic distance among Iberian river populations, suggesting that dispersal following the colonization of fresh water occurred via the sea to nearby, unconnected river basins. The ancestor of S. fluviatilis may have been a euryhaline species, allowing incursions into fresh water and subsequent dispersal via the sea. This dispersal scenario could theoretically be combined with multiple colonization episodes. The two old lake populations shared a unique allele at the Pgdh-A locus in high frequency with its closest relative S. pave, which was absent from other populations. This may indicate two initial incursions into fresh water by a wide-ranging marine ancestor that possessed this allele. Differential selection on this allele in lake habitats or convergence are less likely possibilities. Thus, the present distribution of S. fluviatilis appears to stem from a combination of "raceme" origins (i.e., more than one colonization episode) and subsequent dispersal and divergence in new watersheds. C1 Museo Nacl Ciencias Nat, Dept Biodiversidad, Madrid 28006, Spain. Univ E Anglia, Sch Biol Sci, Norwich NR4 7TJ, Norfolk, England. Aristotelian Univ Salonika, Lab Ichthyol, GR-54006 Salonika, Greece. RP Perdices, A (reprint author), Smithsonian Trop Res Inst, Aptdo 2072, Balboa, Panama. RI Machordom, Annie/K-1737-2014; Reynolds, John/L-6345-2015; OI Machordom, Annie/0000-0003-0341-0809; Reynolds, John/0000-0002-0459-0074; Doadrio, Ignacio/0000-0003-4863-9711 NR 34 TC 15 Z9 18 U1 0 U2 6 PU AMER SOC ICHTHYOLOGISTS HERPETOLOGISTS PI CHARLESTON PA UNIV CHARLESTON, GRICE MARINE LABORATORY, 205 FORT JOHNSON RD, CHARLESTON, SC 29412 USA SN 0045-8511 J9 COPEIA JI Copeia PD AUG 4 PY 2000 IS 3 BP 723 EP 731 DI 10.1643/0045-8511(2000)000[0723:GDAOOM]2.0.CO;2 PG 9 WC Zoology SC Zoology GA 369EV UT WOS:000165053800007 ER PT J AU Lieberman, DE Crompton, AW AF Lieberman, DE Crompton, AW TI Why fuse the mandibular symphysis? A comparative analysis SO AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY LA English DT Article; Proceedings Paper CT 65th Annual Meeting of the American-Association-of-Physical-Anthropologists CY APR 09-13, 1996 CL RES TRIANGLE PK, NORTH CAROLINA SP Amer Assoc Phys Anthropologists DE symphysis; mammals; primates; electromyograms; mandible; mastication ID MASSETER MUSCLE FUNCTION; INVIVO BONE STRAIN; MACACA-FASCICULARIS; GALAGO CRASSICAUDATUS; JAW MOVEMENTS; MASTICATION; PRIMATES; FORCE; ELECTROMYOGRAMS; MORPHOLOGY AB Fused symphyses, which evolved independently in several mammalian Laxa, including anthropoids, are stiffer and stronger than unfused symphyses. This paper tests the hypothesis that orientations of tooth movements during occlusion are the primary basis for variations in symphyseal fusion. Mammals whose teeth have primarily dorsally oriented occlusal trajectories and/or rotate their mandibles during occlusion will not benefit from symphyseal fusion because it prevents independent mandibular movements and because unfused symphyses transfer dorsally oriented forces with equal efficiency; mammals with predominantly transverse power strokes are predicted to benefit from symphyseal fusion or greatly restricted mediolateral movement at the symphysis in order to increase force transfer efficiency across the symphysis in the transverse plane. These hypotheses are tested with comparative data on symphyseal and occlusal morphology in several mammals, and with kinematic and EMG analyses of mastication in opossums (Didelphis virginiana) and goats (Capra hircus) that are compared with published data on chewing in primates. Among mammals, symphyseal fusion or a morphology that greatly restricts movement correlates significantly with occlusal orientation: species with more transversely oriented occlusal planes tend to have fused symphyses. The ratio of working- to balancing-side adductor muscle force in goats and opossums is close to 1:1, as in macaques, but goats and opossums have mandibles that rotate independently during occlusion, and have predominantly vertically oriented tooth movements during the power stroke. Symphyseal fusion is therefore most likely an adaptation for increasing the efficiency of transfer of transversely oriented occlusal forces in mammals whose mandibles do not rotate independently during the power stroke. (C) 2000 Wiley-Liss, Inc. C1 George Washington Univ, Dept Anthropol, Washington, DC 20052 USA. Smithsonian Inst, Natl Museum Nat Hist, Human Origins Program, Washington, DC 20560 USA. Harvard Univ, Museum Comparat Zool, Cambridge, MA 02138 USA. RP Lieberman, DE (reprint author), George Washington Univ, Dept Anthropol, 2110 G St NW, Washington, DC 20052 USA. NR 61 TC 50 Z9 58 U1 1 U2 5 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0002-9483 J9 AM J PHYS ANTHROPOL JI Am. J. Phys. Anthropol. PD AUG PY 2000 VL 112 IS 4 BP 517 EP 540 DI 10.1002/1096-8644(200008)112:4<517::AID-AJPA7>3.3.CO;2-W PG 24 WC Anthropology; Evolutionary Biology SC Anthropology; Evolutionary Biology GA 341ZY UT WOS:000088621900006 PM 10918127 ER PT J AU Schlegel, EM Blair, WP Fesen, RA AF Schlegel, EM Blair, WP Fesen, RA TI ROSAT HRI and ASCA observations of the spiral galaxy NGC 6946 and its northeast complex of luminous supernova remnants SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : individual (NGC 6946); galaxies : spiral; supernova remnants; X-rays ID X-RAY SURVEY; BLACK-HOLES; CYGNUS LOOP; NGC-6946; EMISSION; NUCLEI AB Analysis of 80 ks ASCA and 60 ks ROSAT HRI observations of the face-on spiral galaxy NGC 6946 are presented. The ASCA image is the first observation of this galaxy above similar to 2 keV. Diffuse emission may be present in the inner similar to 4' extending to energies above similar to 2-3 keV. In the HRI data, 14 pointlike sources are detected, the brightest two being a source very close to the nucleus and a source to the northeast that corresponds to a luminous complex of interacting supernova remnants (SNRs). We detect a point source that lies similar to 30 " west of the SNR complex but with a luminosity similar to 1/15 of the SNR complex. None of the point sources show evidence of strong variability; weak variability would escape our detection. The ASCA spectrum of the SNR complex shows evidence for an emission line at similar to 0.9 keV that could be either Ne nr at similar to 0.915 keV or a blend of ion stages of Fe L-shell emission if the continuum is fitted with a power law. However, a two-component, Raymond-Smith thermal spectrum with no lines gives an equally valid continuum fit and may be more physically plausible given the observed spectrum below 3 keV. Adopting this latter model, we derive a density for the SNR complex of 10-35 cm(-3), consistent with estimates inferred from optical emission-line ratios. The complex's extraordinary X-ray luminosity may be related more to the high density of the surrounding medium than to a small but intense interaction region where two of the complex's SNRs are apparently colliding. C1 Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Dartmouth Coll, Dept Phys & Astron, Wilder Lab 6127, Hanover, NH 03755 USA. RP Schlegel, EM (reprint author), Smithsonian Astrophys Observ, 60 Garden St, Cambridge, MA 02138 USA. NR 47 TC 20 Z9 20 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD AUG PY 2000 VL 120 IS 2 BP 791 EP 800 DI 10.1086/301498 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 349HZ UT WOS:000089040800022 ER PT J AU Mochejska, BJ Macri, LM Sasselov, DD Stanek, KZ AF Mochejska, BJ Macri, LM Sasselov, DD Stanek, KZ TI The direct project: Influence of blending on the cepheid distance scale. I. Cepheids in M31 SO ASTRONOMICAL JOURNAL LA English DT Article DE Cepheids; distance scale; galaxies : individual (M31); stars : variable : other ID DETACHED ECLIPSING BINARIES; PERIOD-LUMINOSITY RELATION; HUBBLE-SPACE-TELESCOPE; LARGE-MAGELLANIC-CLOUD; KEY PROJECT; VARIABLES; CALIBRATION; BRIGHTNESS; PHOTOMETRY; WCSTOOLS AB We investigate the influence of blending on the Cepheid distance scale. Blending is the close association of a Cepheid with one or more intrinsically luminous stars. High-resolution HST images are compared with our ground-based data, obtained as part of the DIRECT project, for a sample of 22 Cepheids in the M31 galaxy. The average (median) V-band flux contribution from luminous companions that are not resolved on the ground-based images is about 19% (12%) of the flux of the Cepheid. This is a large effect-at the 10% level for distances. The current Cepheid distance estimates to M31 are all ground based and are thus affected (underestimated). We discuss indirect methods to find which Cepheids are blended, e.g., by the use of well-sampled light curves in at least two optical bands. More generally, our ground-based resolution in M31 corresponds to the HST resolution at about 10 Mpc. Blending leads to systematically low distances in the observed galaxies and therefore to systematically high estimates of Ho; we discuss the issue and the implications. C1 Copernicus Astron Ctr, PL-00716 Warsaw, Poland. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Mochejska, BJ (reprint author), Copernicus Astron Ctr, Bartycka 18, PL-00716 Warsaw, Poland. NR 40 TC 55 Z9 55 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD AUG PY 2000 VL 120 IS 2 BP 810 EP 820 DI 10.1086/301493 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 349HZ UT WOS:000089040800024 ER PT J AU Ayala, S Noriega-Crespo, A Garnavich, PM Curiel, S Raga, AC Bohm, KH Raymond, J AF Ayala, S Noriega-Crespo, A Garnavich, PM Curiel, S Raga, AC Bohm, KH Raymond, J TI Optical and near-infrared study of the Cepheus E outflow, a very low-excitation object SO ASTRONOMICAL JOURNAL LA English DT Article DE infrared radiation; ISM : individual (Cepheus E, HH 377); ISM : jets and outflows ID HERBIG-HARO OBJECTS; MOLECULAR-HYDROGEN; CEP-E; H-2 FLUORESCENCE; EMISSION; SHOCK; JETS; SPECTROSCOPY; IONIZATION; EXTINCTION AB We present images and spectra of the Cepheus E (Cep E) region at both optical and infrared wavelengths. Only the brightest region of the southern lobe of the Cep E outflow reveals optical emission, suggesting that the extinction close to the outflow source plays an important role in the observed difference between the optical and IR morphologies. Cep E is a unique object since it provides a link between the spectroscopic properties of the optical Herbig-Haro (HH) objects and those of deeply embedded outflows. The observed H-2 infrared lines allow us to determine an excitation temperature of similar to 2300 K, an Ortho-to-Para ratio of similar to 3, and an H-2 (1, 0)/(2, 1) S(1) line ratio of similar to 9. These results are consistent with the values observed for WH objects with detected NIR emission lines, with shock excitation as the main mechanism for their formation, and also with the values observed for embedded, NIR flows. The optical spectroscopic characteristics of Cep E (HH 377) appear to be similar to the ones of low-excitation HH objects. However, the electron density determined from the CS nl lambda lambda 6731/6717 line ratio for this object (n(e) = 4100 cm(-3)), and the [O I] lambda 6300/H alpha, [S II] lambda lambda(6717 + 6731)/H alpha ratios are higher than the values of all of the previously studied low-excitation HH objects. This result is likely to be the consequence of an anomalously high environmental density in the HH 377 outflow. The ionization fraction obtained for HH 377 is x(e) similar to 1%. From this result, together with the observed [O I] lambda 6300/H alpha line ratio, we conclude that the observed H alpha line emission is collisionally excited. From a comparison with shock models, we also conclude that the extinction toward HH 377 is very low. Comparing the observed H beta and H alpha fluxes of HH 377 with model predictions, we determine a shock speed between 15 and 20 km s(-1), although somewhat higher velocities also produce spectra with line ratios that qualitatively agree with the observations of HH 377. C1 Univ Nacl Autonoma Mexico, Inst Astron, Mexico City 04510, DF, Mexico. CALTECH, SIRTF Sci Ctr, IPAC, Pasadena, CA 91125 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Ayala, S (reprint author), Univ Nacl Autonoma Mexico, Inst Astron, Apdo Postal 70-264, Mexico City 04510, DF, Mexico. NR 37 TC 13 Z9 13 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD AUG PY 2000 VL 120 IS 2 BP 909 EP 919 DI 10.1086/301500 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 349HZ UT WOS:000089040800032 ER PT J AU Puzia, TH Kissler-Patig, M Brodie, JP Huchra, JP AF Puzia, TH Kissler-Patig, M Brodie, JP Huchra, JP TI The age difference between the globular cluster subpopulations in NGC 4472 (vol 118, pg 2734, 1999) SO ASTRONOMICAL JOURNAL LA English DT Correction C1 Univ Bonn, Sternwarte, D-5300 Bonn, Germany. European So Observ, Garching, Germany. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Puzia, TH (reprint author), Univ Bonn, Sternwarte, D-5300 Bonn, Germany. NR 1 TC 3 Z9 3 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD AUG PY 2000 VL 120 IS 2 BP 1160 EP 1160 DI 10.1086/301508 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 349HZ UT WOS:000089040800055 ER PT J AU Refsdal, S Stabell, R Pelt, J Schild, R AF Refsdal, S Stabell, R Pelt, J Schild, R TI Constraints on source and lens parameters from microlensing variability in QSO 0957+561 A,B SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE cosmology : gravitational lensing; galaxies : quasars : individual : QSO 0957+561 ID QUASAR Q0957+561; TIME-DELAY; QSO-0957+561; STARS AB From regular monitoring of the Double Quasar QSO 0957+561 A,B there is now general agreement on a time delay of about 416 days. This has made it possible to determine the microlensing residual in the light-curve, see Pelt et al. (1998). We have used two significant microlensing features: 1) A "quiet" period with a variability less than 0.05 mag lasting about 8 years, and 2) A change in the residual of 0.25 mag during a time interval of about 5 years. The first feature gives a lower limit for the lens mass, M, for a given normalized source radius, r, whereas the second feature gives an upper limit. We have considered the amount of mass in a continuum to be a free parameter with possible values between 0% (all mass in lenses) and 90%. At a significance level of 1% the mass can only be constrained within a rather wide range (10(-6)M. to 5M.). For the radius R of the source an upper limit of 10(16) cm is found, whereas the normalized source radius r is restricted to be smaller than 30. At a level of 10%, however, the range of possible masses is much narrower (2.10(-3) M. to 0.5M.), and the upper limit of R is about 6 . 10(15) cm, whereas the value of r is restricted to be less than 2. We have used an effective transverse velocity V equal to 600 km s(-1). C1 Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway. Hamburger Sternwarte, D-21029 Hamburg, Germany. Tartu Observ, EE-61602 Toravere, Estonia. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Ctr Adv Study, N-0271 Oslo, Norway. RP Refsdal, S (reprint author), Univ Oslo, Inst Theoret Astrophys, POB 1029, N-0315 Oslo, Norway. EM rolf.stabell@astro.uio.no RI Pelt, Jaan/G-4916-2010 NR 16 TC 29 Z9 29 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD AUG PY 2000 VL 360 IS 1 BP 10 EP 14 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 345PN UT WOS:000088824500004 ER PT J AU Perez-Torres, MA Marcaide, JM Guirado, JC Ros, E Shapiro, II Ratner, MI Sardon, E AF Perez-Torres, MA Marcaide, JM Guirado, JC Ros, E Shapiro, II Ratner, MI Sardon, E TI Towards global phase-delay VLBI astrometry: observations of QSO 1150+812 and BL 1803+784 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE astrometry; techniques : interferometric; galaxies : quasars : individual : QSO 1150+812; galaxies : BL Lacertae objects : individual : BL 1803+784 ID BASE-LINE INTERFEROMETRY; RADIO INTERFEROMETRY; PROPER MOTION; ANGULAR SEPARATION; COMPLETE SAMPLE; REFERENCE-FRAME; 1038+528-A; GEODESY; OBJECTS; PEAK AB On 18 November 1993, we observed the QSO 1150+812 and the BL Lac object 1803+784, nearly 15 degrees apart on the sky, with a VLBI array, simultaneously recording at 8.4 and 2.3 GHz. Using difference astrometry techniques, we determined the coordinates of 1803+784 relative to those of 1150+812 to be Delta alpha = 6(h) 7(m) 33(s).18469 +/- 0.(s)00020 Delta delta = -2 degrees 30'25." 13557 +/- 0." 00075. These standard errors contain estimated contributions from the propagation medium, the effects of source opacity, and the possible misidentification of the reference point in some of the maps. We obtained comparably accurate and consistent relative positions of the radio sources with GPS-based ionosphere corrections, thus demonstrating that dual-frequency observations are not required for state-of-the-art accuracy in VLBI astrometry. These results also demonstrate the feasibility of using single-frequency measurements for sources separated by 15 degrees on the sky, and open the avenue for the application of this technique on a full-sky scale. C1 Univ Valencia, Dept Astron & Astrofis, E-46100 Burjassot, Valencia, Spain. CSIC, INTA, Ctr Astrobiol, Madrid 26650, Spain. Max Planck Inst Radioastron, D-53121 Bonn, Germany. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. GMV, Madrid 28760, Spain. RP Perez-Torres, MA (reprint author), Ist Radioastron, Via P Gobetti 101, I-40129 Bologna, Italy. EM torres@ira.bo.cnr.it NR 32 TC 9 Z9 9 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD AUG PY 2000 VL 360 IS 1 BP 161 EP 170 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 345PN UT WOS:000088824500018 ER PT J AU Bouwman, J de Koter, A van den Ancker, ME Waters, LBFM AF Bouwman, J de Koter, A van den Ancker, ME Waters, LBFM TI The composition of the circumstellar dust around the Herbig Ae stars AB Aur and HD 163296 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE radiative transfer; stars : circumstellar matter; stars : formation; stars : individual : AB Aur; stars : individual :; HD 163296; stars : pre-main sequence ID PROTOPLANETARY ACCRETION DISKS; SPECTRAL ENERGY-DISTRIBUTIONS; INTERMEDIATE-MASS STARS; AE/BE STARS; INTERSTELLAR-MEDIUM; CHEMICAL-REACTIONS; OPTICAL-CONSTANTS; BETA-PICTORIS; GRAINS; AURIGAE AB We have analysed the 2-200 mu m ISO spectra of two bright Herbig Ae stars, AB Aur and HD 163296, in order to derive the composition and mass over temperature distribution of the circumstellar dust. We find that the two stars have a similar composition of the dust, however also with some important differences. We address the onset of the strong near-infrared emission between 1-4 mu m. We show that this emission can be explained with thermal emission from metallic iron or dust species containing iron. The circumstellar dust surrounding both stars shows two distinct regimes in the mass over temperature distributions with temperatures of similar to 10(3) and similar to 10(2) K. Modelling of the ISO spectra further reveal a significant deviation of the derived grain sizes compared to the interstellar grain size distribution. A population of large (similar to 1 mm) grains is required to explain the observed (sub-) millimetre fluxes of HD 163296. The presence of crystalline silicates and the larger grain sizes in HD 163296 compared to AB Aur suggests that the former star is a more evolved system. Amorphous silicates make out the bulk of the dust mass in both stars. It is likely that a significant fraction of the dust is carbon-rich. We find strong evidence for a 20-30 mu m band which we tentatively attribute to FeO. C1 Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Katholieke Univ Leuven, Inst Sterrenkunde, B-3001 Heverlee, Belgium. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Bouwman, J (reprint author), Univ Amsterdam, Astron Inst Anton Pannekoek, Kruislaan 403, NL-1098 SJ Amsterdam, Netherlands. EM jeroenb@astro.uva.nl NR 57 TC 85 Z9 86 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD AUG PY 2000 VL 360 IS 1 BP 213 EP 226 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 345PN UT WOS:000088824500023 ER PT J AU Piraino, S Santangelo, A Kaaret, P AF Piraino, S Santangelo, A Kaaret, P TI Detection of a broad iron emission line and sub-millisecond quasiperiodic oscillations from the type I X-ray burster 4U 1728-34 in a high state SO ASTRONOMY & ASTROPHYSICS LA English DT Letter DE accretion, accretion disks; stars : individual; stars : neutron; X-rays : stars ID K LINE; ASTRONOMY SATELLITE; TIMING EXPLORER; ON-BOARD; BINARIES; MODEL AB We report results from simultaneous RossiXTE and BeppoSAX observations of the neutron-star x-ray binary and type I X-ray burster 4U 1728-34. The source was found in a high luminosity state, L-X similar to 0.1L(Edd), and quasiperiodic oscillations were detected at 1284+/-6 Hz, the highest frequency ever observed from this source. The x-ray spectrum shows a broad, FWHM similar to 0.8 keV, iron K-alpha fluorescence line. We discuss interpretations of the broad line and the quasiperiodic oscillations and how future simultaneous spectral and timing observations can be used to test these interpretations and, potentially, to estimate the mass of the compact object. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CNR, IFCAI, I-90146 Palermo, Italy. RP Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM pkaaret@cfa.harvard.edu NR 27 TC 20 Z9 20 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1432-0746 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD AUG PY 2000 VL 360 IS 3 BP L35 EP L38 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 357JJ UT WOS:000089494500002 ER PT J AU Mandolesi, N Bersanelli, M Burigana, C Gorski, KM Hivon, E Maino, D Valenziano, L Villa, F White, M AF Mandolesi, N Bersanelli, M Burigana, C Gorski, KM Hivon, E Maino, D Valenziano, L Villa, F White, M TI On the performance of Planck-like telescopes versus mirror aperture SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Article DE cosmology : cosmic microwave background; methods : data analysis; telescopes ID MICROWAVE; SATELLITE; SKY AB Future space mission like MAP and PLANCK will be able to shade new light on our knowledge of the Universe thanks to their unprecedented angular resolution and sensitivity. The far sub-degree angular resolution is obtained coupling usual detectors, radiometers and/or bolometers, to an optical system, namely a telescope. The wealth of cosmological information is encoded at high l values (similar to 1000) which can be reached with resolution of about 10'. Distortions of the main beam resulting from the current focal plane arrangement and the optical design of the PLANCK satellite will degrade angular resolution and sensitivity per resolution element possibly compromising the final results. The detailed design of the PLANCK telescope is continuously changing with the aim of optimizing its performance. In the present work we present a methodological study on the relation between telescope optical design, focal plane arrangement and optical performances, focussing on the dependence of angular resolution on primary mirror aperture. Different independent approaches have been developed to quantify the impact of main bt am distortions on cosmic microwave background (CMB) science yielding nearly the same results. The so-called PHASE-A telescope is unacceptable with respect mission main goals. Larger telescopes (namely with effective agm aperture greater than or similar to 1.5 m) are therefore preferable. This paper is based on the PLANCK LFI activities. C1 CNR, Ist TESRE, I-40129 Bologna, Italy. CNR, IFC, I-20133 Milan, Italy. European So Observ, D-85748 Garching, Germany. CALTECH, Pasadena, CA 91125 USA. Int Sch Adv Studies, SISSA, I-34014 Trieste, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Mandolesi, N (reprint author), CNR, Ist TESRE, Via Gobetti 101, I-40129 Bologna, Italy. RI White, Martin/I-3880-2015; OI White, Martin/0000-0001-9912-5070; Valenziano, Luca/0000-0002-1170-0104; Burigana, Carlo/0000-0002-3005-5796; Villa, Fabrizio/0000-0003-1798-861X; Hivon, Eric/0000-0003-1880-2733 NR 34 TC 20 Z9 20 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD AUG PY 2000 VL 145 IS 2 BP 323 EP 340 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347XD UT WOS:000088953700015 ER PT J AU McCarthy, MC Apponi, AJ Gottlieb, CA Thaddeus, P AF McCarthy, MC Apponi, AJ Gottlieb, CA Thaddeus, P TI Laboratory detection of five new linear silicon carbides: SiC3, SiC5, SiC6, SiC7, and SiC8 SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : molecules; line : identification; methods : laboratory; molecular data; molecular processes; radio lines : ISM ID ROTATIONAL SPECTRUM; CARBON MONOXIDES; RHOMBOIDAL SIC3; SPECTROSCOPY; IDENTIFICATION; CLUSTERS; ISOMERS AB The rotational spectra of five highly polar linear silicon-carbon chains SiCn, n = 3 and 5-8, were detected by Fourier transform microwave spectroscopy in a supersonic molecular beam among the products of a gas discharge through silane and diacetylene; SiC3 was detected as well by conventional millimeter-wave absorption spectroscopy in a large glow discharge through silane and acetylene. The electronic ground state was found to be X(1)Sigma(+) for those with even n and X(3)Sigma(-) for those with odd n, in agreement with recent ab initio calculations. The rotational and centrifugal distortion constants of all five molecules were determined to high accuracy, as were the spin-spin and spin-rotation coupling constants for triplet SiC3, SiC5, and SiC7. A fairly steep increase in the magnitude of the spin-spin constant with chain length, similar to that found previously for the C-n and CnO chains, was observed for the present silicon carbides. Of the five new silicon carbides, SiC3 is of particular astronomical interest because radio emission lines of the isomeric ground state, a compact rhomboidal ring, have recently been detected in IRC+10216 and because this chain is calculated to possess a large dipole moment of 4.8 D and to lie only 5 kcal mol(-1) above ground. From the laboratory data, the most intense transitions of SiC3 can now be calculated to better than 1 km s(-1) in equivalent radial velocity at frequencies up to 300 GHz. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. RP McCarthy, MC (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI McCarthy, Michael/0000-0001-9142-0008 NR 25 TC 46 Z9 46 U1 2 U2 17 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 2000 VL 538 IS 2 BP 766 EP 772 DI 10.1086/309177 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 345PR UT WOS:000088824800030 ER PT J AU Evans, NR Seward, FD AF Evans, NR Seward, FD TI Settling onto the main sequence: ROSAT observations of h and chi Persei SO ASTROPHYSICAL JOURNAL LA English DT Article DE open clusters and associations : individual (chi Persei, h Persei); stars : formation; stars : pre-main-sequence; X-rays : stars ID YOUNG OPEN CLUSTER; X-RAY; ALPHA-PERSEI; DARK CLOUD; STARS AB We have studied X-rays from the double cluster h and chi Per with an 11 ks ROSAT position-sensitive proportional counter (PSPC) observation. Emission is concentrated toward the two cluster centers. Whether the emission is diffuse emission or from a population of unresolved faint sources is uncertain because the resolution is poor at the distance of the clusters (2.4 kpc). Twenty-three sources were found with an X-ray luminosity of log L = 31.5 ergs s(-1) or greater. These sources were found in the cluster nuclei, between the clusters, and in a halo around the cluster pair. The ROSAT PSPC error circle is too large for the identification of X-ray sources with individual optical objects. However, because of a lack of correlation between X-ray sources and B stars, we conclude that the X-rays are produced by late spectral type pre-main-sequence stars. The X-ray sources are brighter than all but the very brightest sources in the younger Orion Nebula cluster, which makes them important in tracing the final stages approaching the main sequence. C1 Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. RP Evans, NR (reprint author), Smithsonian Astrophys Observ, MS 4,60 Garden St, Cambridge, MA 02138 USA. NR 21 TC 1 Z9 1 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 2000 VL 538 IS 2 BP 777 EP 782 DI 10.1086/309162 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 345PR UT WOS:000088824800032 ER PT J AU Dobrzycka, D Raymond, JC Cranmer, SR AF Dobrzycka, D Raymond, JC Cranmer, SR TI Ultraviolet spectroscopy of polar coronal jets SO ASTROPHYSICAL JOURNAL LA English DT Article DE sun : activity; sun : corona; sun : flares; sun : UV radiation ID X-RAY TELESCOPE; SOLAR CORONA; PHYSICAL-PROPERTIES; WHITE-LIGHT; HOLES; SOHO; SPECTROMETER; OUTFLOW; DENSITY AB We have observed a total of five UVCS/S0H0 polar jets that correlate with the Extreme-Ultraviolet Imaging Telescope (EIT) and Large Angle Spectrometric Coronagraph (LASCO) jet events. We analyzed spectroscopic observations of these jets and found that they typically undergo two phases: at the first phase the O vr lines show a brief intensity enhancement (by a factor of 1.4) and narrowing (by a factor of 0.8), while the H I Ly alpha line is not enhanced, and the second phase, about 25 minutes later, when the H I Ly alpha line shows an intensity enhancement (by a factor of 1.3) and narrowing (by a factor of 0.8), while the O VI line is relatively unchanged. We modeled the observable properties of the jets from 1997 August 5, detected at 1.71 R.. We interpret the first phase as the fast, dense centroid of the jet passing by the UVCS slit. The empirical jet model was able to reproduce the observed line properties with electron density enhancement by a factor of 3.2 (with a resulting density of 4.5 x 10(6) cm(-3)), an electron temperature decrease (change by a factor of 0.50 to 750,000 K), and the centroid outflow velocity larger than 280 km s(-1). During the second phase, the model required a further decrease in the electron temperature (change by a factor of 0.10, with a jet temperature of only 150,000 K), along with a weaker electron density (1.7 x 10(6) cm(-3)) and an outflow velocity of 205 km s(-1). Possible scenarios of the electron temperature variations needed to account for observed conditions on 1997 August 5 indicate that some heating is required. We computed models of the temperature and nonequilibrium ionization state of an expanding plasma using various forms for the heating rates. We found that the jet had to leave the Sun at an electron temperature below 2.5 x 10(6) K and that a heating rate of the same order as the average coronal hole heating is required. Such low initial temperatures are consistent with the idea that the jets observed by LASCO, EIT, and UVCS are different than previously observed coronal X-ray jets. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Dobrzycka, D (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 29 TC 16 Z9 16 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 2000 VL 538 IS 2 BP 922 EP 931 DI 10.1086/309173 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 345PR UT WOS:000088824800047 ER PT J AU Edgar, RJ Esser, R AF Edgar, RJ Esser, R TI Nonequilibrium ionization and first ionization potential effect diagnostics SO ASTROPHYSICAL JOURNAL LA English DT Article DE solar wind; Sun : abundances; Sun : corona AB We examine the accuracy of a common first ionization potential effect diagnostic, the ratio of Ne VI to Mg VI lines in the solar transition region. Since the two ions have quite similar contribution functions near their maxima in equilibrium, the ratio of these two ions is often taken to be the abundance ratio of Ne and Mg. First we compute nonequilibrium ionization effects on the ratio f(Ne+5)/f(Mg+5) of ion fractions for a variety of simple flows through the transition region. Calculating the spectral line ratios for a few examples, we then show that nonequilibrium effects as well as temperature and density dependence must be evaluated for each line ratio used in the diagnostics. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Edgar, RJ (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 13 TC 2 Z9 2 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 2000 VL 538 IS 2 BP L167 EP L170 DI 10.1086/312806 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 345PU UT WOS:000088825000017 ER PT J AU Perna, R Heyl, J Hernquist, L AF Perna, R Heyl, J Hernquist, L TI Consequences of interstellar absorption for models of anomalous X-ray pulsars SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : neutron; X-rays : stars ID MAGNETIZED NEUTRON-STARS; SURFACE-TEMPERATURE; ROSAT DATA AB We examine properties of thermal radiation emitted by strongly magnetized neutron stars (NSs). In particular, we show that the pulsation amplitudes of the energy-integrated flux are an increasing function of the absorption column density to the source. This is especially important for the interpretation of the anomalous X-ray pulsars as cooling NSs with high magnetic fields. We show that the high-pulsation amplitudes observed in these objects are consistent with cooling models if the large amount of absorption to these sources is taken into account. We also show that cooling models imply inferred radii of the emitting regions on the order of similar to 5-6 times smaller than the actual NS radii, again in agreement with observations. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, Pasadena, CA 91125 USA. RP Perna, R (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 27 TC 10 Z9 10 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 2000 VL 538 IS 2 BP L159 EP L161 DI 10.1086/312820 PN 2 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 345PU UT WOS:000088825000015 ER PT J AU Vestergaard, M Wilkes, BJ Barthel, PD AF Vestergaard, M Wilkes, BJ Barthel, PD TI Clues to quasar broad-line region geometry and kinematics SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; quasars : emission lines ID ACTIVE GALACTIC NUCLEI; HIGH-REDSHIFT QUASARS; RADIO-LOUD QUASARS; EMISSION-LINES; QSOS; PROFILES; IONIZATION; MODEL; WINDS; GAS AB We present evidence that the high-velocity C IV lambda 1549 emission-line gas of radio-loud quasars may originate in a disklike configuration, in close proximity to the accretion disk often assumed to emit the low-ionization lines. For a sample of 36 radio-loud z approximate to 2 quasars, we find the 20%-30% peak widths to show significant inverse correlations with the fractional radio core-flux density R, which is the radio axis inclination indicator. Highly inclined systems have broader fine wings, consistent with a high-velocity field perpendicular to the radio axis. By contrast, the narrow line core shows no such relation with R, so the lowest velocity C IV-emitting gas has an inclination-independent velocity field. We propose that this low-velocity gas is located at higher disk altitudes than the high-velocity gas. A planar origin of the high-velocity C IV emission is consistent with the current results and with an accretion disk wind emitting the broad lines. A spherical distribution of randomly orbiting broad-line clouds and a polar high-ionization outflow are ruled out. C1 Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Copenhagen Univ Observ, Niels Bohr Inst Astron Phys & Geophys, DK-2100 Copenhagen O, Denmark. Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands. RP Vestergaard, M (reprint author), Ohio State Univ, Dept Astron, 140 W 18th Ave, Columbus, OH 43210 USA. EM vester@astronomy.ohio-state.edu; bwilkes@cfa.harvard.edu; pdb@astro.rug.nl RI Vestergaard, Marianne/M-5247-2014 OI Vestergaard, Marianne/0000-0001-9191-9837 NR 35 TC 37 Z9 37 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 2000 VL 538 IS 2 BP L103 EP L106 DI 10.1086/312805 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 345PU UT WOS:000088825000002 ER PT J AU Woo, R Armstrong, JW Habbal, SR AF Woo, R Armstrong, JW Habbal, SR TI Observed associations between the solar interior, corona, and solar wind SO ASTROPHYSICAL JOURNAL LA English DT Article DE solar wind; Sun : corona; Sun : interior ID DENSITY STRUCTURE; ULYSSES; ROTATION; SURFACE; CYCLE; FLOWS; GONG; SUN AB Using polarized brightness (pB) measurements made by the High Altitude Observatory (HAO) Mauna Loa Mk III K-coronameter, we investigate the daily changes of path-integrated density at 1.15 R-circle dot. During 1996, when simultaneous pB and helioseismology data were available, we find that the correlation of pB (at zero time lag and 20 degrees latitude lag) varies with latitude in the same way that the subsurface differential rotation inferred from helioseismology does. The association is such that bands of higher pB correlation are associated with retrograde subsurface rotation and that lower pB correlation bands are associated with prograde subsurface rotation. We also show that polar coronal holes are distinguished by a nonrecurring longitudinal structure as opposed to a recurring structure in the quiet Sun. In addition, the levels of pB and standard deviation sigma(pB) of pB are about half of those of the neighboring quiet Sun. These statistical characteristics of coronal density in polar holes and the quiet Sun were also present in 1993-1994 and are replicated in the statistics of the distant solar wind observed by Ulysses. The association of the density (pB) correlation with subsurface flow (when simultaneous data were available in 1996), together with the association of the latitudinal dependence of the statistical characteristics (average, standard deviation, and autocorrelation function) of the coronal (pB) and solar wind (Ulysses) density (when simultaneous data were available in 1993-1994), suggest a correlated variability of subsurface flow, coronal density, and solar wind density organized by solar latitude. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Woo, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 23 TC 9 Z9 9 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 2000 VL 538 IS 2 BP L171 EP L174 DI 10.1086/312803 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 345PU UT WOS:000088825000018 ER PT J AU Bohringer, H Voges, W Huchra, JP McLean, B Giacconi, R Rosati, P Burg, R Mader, J Schuecker, P Simic, D Komossa, S Reiprich, TH Retzlaff, J Trumper, J AF Bohringer, H Voges, W Huchra, JP McLean, B Giacconi, R Rosati, P Burg, R Mader, J Schuecker, P Simic, D Komossa, S Reiprich, TH Retzlaff, J Trumper, J TI The northern ROSAT All-Sky (NORAS) galaxy cluster survey. I. X-ray properties of clusters detected as extended X-ray sources SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Review DE galaxies : clusters : general; large-scale structure of universe; surveys; X-rays : galaxies ID MEDIUM SENSITIVITY SURVEY; ECLIPTIC POLE SURVEY; FLUX-LIMITED SAMPLE; CFA REDSHIFT SURVEY; ESO IMAGING SURVEY; N-LOG-S; RICH CLUSTERS; ABELL CLUSTERS; VELOCITY DISPERSIONS; OPTICAL SPECTROSCOPY AB In the construction of an X-ray-selected sample of galaxy clusters for cosmological studies, we have assembled a sample of 495 X-ray sources found to show extended X-ray emission in the first processing of the ROSAT All-Sky Survey. The sample covers the celestial region with declination delta greater than or equal to 0 degrees and Galactic latitude \b(II)\ greater than or equal to 20 degrees and comprises sources with a count rate greater than or equal to 0.06 counts s(-1) and a source extent likelihood of L greater than or equal to 7. In an optical follow-up identification program we find 378 (76%) of these sources to be clusters of galaxies. It was necessary to reanalyze the sources in this sample with a new X-ray source characterization technique to provide more precise values for the X-ray flux and source extent than obtained from the standard processing. This new method, termed growth curve analysis (GCA), has the advantage over previous methods in its ability to be robust, to be easy to model and to integrate into simulations, to provide diagnostic plots for visual inspection, and to make extensive use of the X-ray data. The source parameters obtained assist the source identification and provide more precise X-ray fluxes. This reanalysis is based on data from the more recent second processing of the ROSAT Survey. We present a catalog of the cluster sources with the X-ray properties obtained as well as a list of the previously flagged extended sources that are found to have a noncluster counterpart. We discuss the process of source identification from the combination of optical and X-ray data. To investigate the overall completeness of the cluster sample as a function of the X-ray flux limit, we extend the search for X-ray cluster sources to the data of the second processing of the ROSAT Survey for the northern sky region between 9(h) and 14(h) in right ascension. We include the search for X-ray emission of known clusters as well as a new investigation of extended X-ray sources. In the course of this search we find X-ray emission from 85 additional Abell clusters and 56 very probable cluster candidates among the newly found extended sources. A comparison of the X-ray cluster number counts of the NORAS sample with the ROSAT-ESO Flux-limited X-Ray (REFLEX) Cluster Survey results leads to an estimate of the completeness of the NORAS sample of ROSAT All-Sky Survey (RASS) I extended clusters of about 50% at an X-ray flux of F-X(0.1-2.4 keV) = 3 x 10(-12) ergs s(-1) cm(-2). The estimated completeness achieved by adding the supplementary sample in the study area amounts to about 82% in comparison to REFLEX. The low completeness introduces an uncertainty in the use of the sample for cosmological statistical studies that will be cured with the completion of the continuing Northern ROSAT All-Sky (NORAS) Cluster Survey project. C1 Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. ESO, D-85748 Garching, Germany. Space Telescope Sci Inst, Cambridge, MA 02138 USA. RP Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. NR 147 TC 334 Z9 335 U1 1 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 EI 1538-4365 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD AUG PY 2000 VL 129 IS 2 BP 435 EP 474 DI 10.1086/313427 PG 40 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 370PL UT WOS:000165131400002 ER PT J AU McCarthy, MC Chen, W Travers, MJ Thaddeus, P AF McCarthy, MC Chen, W Travers, MJ Thaddeus, P TI Microwave spectra of 11 polyyne carbon chains SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE ISM : molecules; line : identification; molecular data; molecular processes; radio lines : ISM ID DENSE INTERSTELLAR CLOUDS; LABORATORY DETECTION; MOLECULES; TMC-1 AB A summary is given of the laboratory study of the rotational spectra of 11 recently detected carbon chain molecules. Classified according to their various end groups, these are the cyanopolyynes HC15N and HC17N; the isocyanopolyynes HC,NC and HC,NC; the methylcyanopolyynes CH3(C--C)(3)CN, CH3(C dropC)(4)CN, and CH3(C dropC)(5)CN; and the methylpolyynes CH3(C dropC)(4)H, CH3(C dropC)(6)H, and CH3(C dropC)(7)H. Measured line frequencies and derived spectroscopic constants are given for each. The microwave laboratory astrophysics of the entire set is now complete in the sense that all the astronomically most interesting rotational transitions, including those with nitrogen quadrupole hyperfine structure, have now been directly measured or can be calculated from the derived constants to a small fraction of 1 km s(-1) in equivalent radial velocity. All 11 carbon chains are candidates for astronomical discovery since they are closely related in structure and composition to ones that have already been discovered in space. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. RP McCarthy, MC (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI McCarthy, Michael/0000-0001-9142-0008 NR 31 TC 101 Z9 101 U1 3 U2 18 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD AUG PY 2000 VL 129 IS 2 BP 611 EP 623 DI 10.1086/313428 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 370PL UT WOS:000165131400008 ER PT J AU Soltis, DE Soltis, PS Chase, MW Mort, ME Albach, DC Zanis, M Savolainen, V Hahn, WH Hoot, SB Fay, MF Axtell, M Swensen, SM Prince, LM Kress, WJ Nixon, KC Farris, JS AF Soltis, DE Soltis, PS Chase, MW Mort, ME Albach, DC Zanis, M Savolainen, V Hahn, WH Hoot, SB Fay, MF Axtell, M Swensen, SM Prince, LM Kress, WJ Nixon, KC Farris, JS TI Angiosperm phylogeny inferred from 18S rDNA, rbcL, and atpB sequences SO BOTANICAL JOURNAL OF THE LINNEAN SOCIETY LA English DT Review DE classification; molecular systematics; large data sets ID RIBOSOMAL DNA-SEQUENCES; PLASTID GENE RBCL; SAXIFRAGACEAE SENSU-LATO; DATA SETS; NUCLEOTIDE-SEQUENCES; CLADISTIC-ANALYSIS; COMPLEX PHYLOGENIES; MORPHOLOGICAL DATA; RNA SEQUENCES; FAMILY AB A phylogenetic analysis of a combined data set for 560 angiosperms and seven outgroups based on three genes, 18S rDNA (1855 bp), rbcL (1428 bp), and atpB (1450 bp) representing a total of 4733 bp is presented. Parsimony analysis was expedited by use of a new computer program, the RATCHET. Parsimony jackknifing was performed to assess the support of clades. The combination of three data sets for numerous species has resulted in the most highly resolved and strongly supported topology yet obtained for angiosperms. In contrast to previous analyses based on single genes, much of the spine of the tree and most of the larger clades receive jackknife support greater than or equal to 50%. Some of the noneudicots form a grade followed by a strongly supported eudicot clade. The early-branching angiosperms are Amborellaceae, Nymphaeaceae, and a clade of Austrobaileyaceae, Illiciaceae, and Schisandraceae. The remaining noneudicots, except Ceratophyllaceae, form a weakly supported core cumagnoliid clads comprising six well-supported subclades: Chloranthaceae, monocots, Winteraceae/Canellaceae, Piperales, Laurales, and Magnoliales. Ceratophyllaceae are sister to the eudicots. Within the well-supported eudicot clade, the early-diverging eudicots (e.g. Proteales, Ranunculales, Trochodendraceae, Sabiaceae) form a grade, followed by the core eudicots, the monophyly of which is also strongly supported. The core eudicots comprise six well-supported subclades: (1) Berberidopsidaceae/Aextoxicaecae; (2) Myrothamnaceae/Gunneraceae; (3) Saxifragales, which are the sister to Vitaceae (including Lee a) plus a strongly supported eurosid clade; (4) Santalales; (5) Caryophyllales, to which Dilleniaceae are sister; and (6) an asterid clade. The relationships among these six subclades of core eudicots do not receive strong support. This large data set has also helped place a number of enigmatic angiosperm families, including Podostemaceae, Aphloiaceae, and Ixerbaceae. This analysis further illustrates the tractability of large data sets and supports a recent, phylogenetically based, ordinal-level reclassification of the angiosperms based largely, but not exclusively, on molecular (DNA sequence) data. (C) 2000 The Linnean Society of London. C1 Washington State Univ, Dept Biol Sci, Pullman, WA 99164 USA. Royal Bot Gardens, Jodrell Lab, Mol Systemat Sect, Richmond TW9 3DS, Surrey, England. Columbia Univ, CERC, New York, NY 10027 USA. Univ Wisconsin, Dept Biol Sci, Milwaukee, WI 53201 USA. Ithaca Coll, Dept Biol, Ithaca, NY 14850 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, Washington, DC 20560 USA. Cornell Univ, Bailey Hortorium, Ithaca, NY 14853 USA. Nat Hist Riksmuseet, Mol Systemat Lab, S-10405 Stockholm, Sweden. RP Soltis, DE (reprint author), Washington State Univ, Dept Biol Sci, Pullman, WA 99164 USA. RI Chase, Mark /A-6642-2011; Albach, Dirk/D-8309-2013; Soltis, Pamela/L-5184-2015; Fay, Michael /G-4741-2010 OI Albach, Dirk/0000-0001-9056-7382; Fay, Michael /0000-0003-3491-9093 NR 123 TC 958 Z9 1028 U1 8 U2 95 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0024-4074 J9 BOT J LINN SOC JI Bot. J. Linnean Soc. PD AUG PY 2000 VL 133 IS 4 BP 381 EP 461 DI 10.1006/bojl.2000.0380 PG 81 WC Plant Sciences SC Plant Sciences GA 347UK UT WOS:000088947400001 ER PT J AU Murray, S Zdziarski, JM Bush, M Citino, SB Schulman, FY Montali, R AF Murray, S Zdziarski, JM Bush, M Citino, SB Schulman, FY Montali, R TI Diverticulitis with rupture and fatal peritonitis in a Sumatran orangutan (Pongo pygmaeus) SO COMPARATIVE MEDICINE LA English DT Article ID JEJUNAL DIVERTICULUM; COMPLICATIONS AB A 30-year-old male Sumatran orangutan (Pongo pygmaeus) presented with signs of depression, lethargy, anorexia, and diarrhea that progressed to acute colic. Exploratory laparotomy revealed fibrinopurulent peritonitis and 50 cm of devitalized small intestine. The surgically resected small intestine contained several mucosal diverticula along the mesenteric attachment; one had ruptured, resulting in peritonitis. Fifteen days after surgery, the orangutan's abdominal incision dehisced. Repeated laparotomy revealed dehiscence of the distal intestinal anastomosis site, as well as extensive adhesions and purulent exudate. The defect was repaired, and the abdomen was extensively irrigated and closed, but the animal died within 24 hours. To our knowledge, this is the first report of diverticulitis in a great ape. Diverticulosis should be considered in the differential diagnosis for great apes that present with signs of depression, lethargy, anorexia, and/or diarrhea. C1 Smithsonian Inst, Natl Zool Pk, Dept Anim Hlth, Washington, DC 20008 USA. Smithsonian Inst, Natl Zool Pk, Dept Pathol, Washington, DC 20008 USA. RP Murray, S (reprint author), Ft Worth Zoo, 1989 Colonial Pkwy, Ft Worth, TX 76110 USA. NR 30 TC 5 Z9 5 U1 0 U2 1 PU AMER ASSOC LABORATORY ANIMAL SCIENCE PI MEMPHIS PA 9190 CRESTWYN HILLS DR, MEMPHIS, TN 38125 USA SN 0023-6764 J9 COMPARATIVE MED JI Comparative Med. PD AUG PY 2000 VL 50 IS 4 BP 452 EP 454 PG 3 WC Veterinary Sciences; Zoology SC Veterinary Sciences; Zoology GA 354MH UT WOS:000089333900018 PM 11020166 ER PT J AU King, DI Rappole, JH AF King, DI Rappole, JH TI Winter flocking of insectivorous birds in montane pine-oak forests in middle America SO CONDOR LA English DT Article DE foraging; mixed-species flocks; Neotropics; vegetation characteristics ID MIXED-SPECIES FLOCKS; WESTERN MEXICO; ADVANTAGES; BEHAVIOUR; PREDATOR; SIZE AB We studied mixed-species insectivorous bird flocks in pine-oak forests in Middle America during three winter seasons to determine whether patterns of hock structure and dynamics were similar to those reported from other tropical sires. We also analyzed patterns of association among bird species, as well as their foraging behavior and the vegetation characteristics associated with birds in flocks. We encountered 333 flocks containing 144 species, of which 26 species had adequate sample sizes for analyses. The size and rate of movement of the hocks were similar to those reported from other Neotropical sires, however, the species richness of our flocks was lower than reported in most other studies, perhaps due to simpler vegetation structure or higher latitude. Only 3 of 50 significant correlations between species pairs were negative, indicating that species generally were not restricted in their participation in mixed-species flocks by other species. In only one instance did we observe correspondence between the association of species-pairs in flocks and their foraging behavior. For most species there was no relationship between association between species-pairs in flocks and vegetation parameters with which they were associated. Thus, additional factors besides foraging facilitation and mutual association with particular vegetation characteristics must be responsible for many of the positive correlations among species pairs. We suggest that non-random association among species within flocks may result in part from enhanced vigilance for predator detection afforded by flock members using similar parts of the environment at the same time. C1 Univ Massachusetts, USDA, Forest Serv, Northeastern Res Stn, Amherst, MA 01003 USA. Smithsonian Conservat & Res Ctr, Front Royal, VA 22630 USA. RP King, DI (reprint author), Univ Massachusetts, USDA, Forest Serv, Northeastern Res Stn, Amherst, MA 01003 USA. NR 34 TC 16 Z9 17 U1 0 U2 5 PU COOPER ORNITHOLOGICAL SOC PI LAWRENCE PA ORNITHOLOGICAL SOC NORTH AMER PO BOX 1897, LAWRENCE, KS 66044-8897 USA SN 0010-5422 J9 CONDOR JI Condor PD AUG PY 2000 VL 102 IS 3 BP 664 EP 672 DI 10.1650/0010-5422(2000)102[0664:WFOIBI]2.0.CO;2 PG 9 WC Ornithology SC Zoology GA 343RX UT WOS:000088716300021 ER PT J AU Rohwer, S Wood, C Bermingham, E AF Rohwer, S Wood, C Bermingham, E TI A new hybrid warbler (Dendroica nigrescens x D-occidentalis) and diagnosis of similar D-townsendi x D-occidentalis recombinants SO CONDOR LA English DT Article DE Dendroica nigrescens; Dendroica occidentalis; Dendroica townsendi; hybrid; warbler ID HERMIT WARBLERS; WOOD-WARBLERS; AVES AB We use 13 color characters to describe the first known Dendroica nigrescens X D. occidentalis hybrid. Because this specimen was collected in the southeastern Cascade Mountains of Washington during the breeding season, D. townsendi, D. occidentalis, and D. nigrescens are the only plausible parents for a hybrid male falling within the black-throated clade of Dendroica warblers. Multiple character states in the hybrid refute the alternative parental combinations, townsendi X occidentalis and townsendi X nigrescens. Two characteristics of this hybrid suggested further tests of the parentage of 38 problematic hybrids that were treated previously as townsendi X occidentalis recombinants by assumption only. These hybrids lack yellow on their breast, the only character that refutes a nigrescens X occidentalis parentage. The new hybrid is intermediate between nigrescens and occidentalis in the color of its posterior face and its anterior crown; thus, we scored these new characters in the 38 problematic hybrids. None of these 38 specimens was intermediate or white in either of these regions, and there was no correlation between having tinges of white in these regions and the extent of flank streaking. These results fail to support nigrescens in the parentage of these 38 specimens; furthermore, none of the problematic hybrids carried a nigrescens mitochondrial DNA haplotype. Thus, we conclude that all are unusual recombinants of townsendi X occidentalis hybridization, rather than nigrescens X occidentalis hybrids. C1 Univ Washington, Burke Museum, Seattle, WA 98195 USA. Univ Washington, Dept Zool, Seattle, WA 98195 USA. Smithsonian Trop Res Inst, Balboa, Panama. RP Rohwer, S (reprint author), Univ Washington, Burke Museum, Box 353010, Seattle, WA 98195 USA. NR 14 TC 2 Z9 2 U1 0 U2 7 PU COOPER ORNITHOLOGICAL SOC PI LAWRENCE PA ORNITHOLOGICAL SOC NORTH AMER PO BOX 1897, LAWRENCE, KS 66044-8897 USA SN 0010-5422 J9 CONDOR JI Condor PD AUG PY 2000 VL 102 IS 3 BP 713 EP 718 DI 10.1650/0010-5422(2000)102[0713:ANHWDN]2.0.CO;2 PG 6 WC Ornithology SC Zoology GA 343RX UT WOS:000088716300032 ER PT J AU McShea, WJ Rappole, JH AF McShea, WJ Rappole, JH TI Managing the abundance and diversity of breeding bird populations through manipulation of deer populations SO CONSERVATION BIOLOGY LA English DT Article ID WHITE-TAILED DEER; LYME-DISEASE RISK; PLANT-COMMUNITIES; FOREST FRAGMENTATION; NORTHERN WISCONSIN; PENNSYLVANIA; REGENERATION; DYNAMICS; NITROGEN; IMPACTS AB Deer densities in forests of eastern North America are thought to have significant effects on the abundance and diversity of forest birds through the role deer play in structuring forest understories. We tested the ability of deer to affect forest bird populations by monitoring the density and diversity of vegetation and birds for 9 years at eight 4-ha sites in northern Virginia, four of which were fenced to exclude deer. Both the density and diversity of understory woody plants increased following deer exclosure. The numerical response of the shrubs to deer exclosure was significantly predicted by the soil quality (ratio of organic carbon to nitrogen) at the sites. Bird populations as a whole increased following exclosure of deer, particularly for ground and intermediate canopy species. The diversity of birds did not increase significantly following exclosure of deer, however, primarily because of replacement of species as understory vegetation proceeded through successional processes. Changes in understory vegetation accounted for most of the variability seen in the abundance and diversity of bird populations. Populations of deer in protected areas are capable of causing significant shifts in the composition and abundance of bird communities. These shifts can be reversed by increasing the density and diversity of understory vegetation, which can be brought about by reducing deer density. C1 Conservat & Res Ctr, Front Royal, VA 22630 USA. RP McShea, WJ (reprint author), Conservat & Res Ctr, Natl Zool Pk, Front Royal, VA 22630 USA. NR 48 TC 106 Z9 110 U1 2 U2 39 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0888-8892 J9 CONSERV BIOL JI Conserv. Biol. PD AUG PY 2000 VL 14 IS 4 BP 1161 EP 1170 DI 10.1046/j.1523-1739.2000.99210.x PG 10 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 338UV UT WOS:000088442400025 ER PT J AU Janik, M Kleinhans, FW Hagedorn, M AF Janik, M Kleinhans, FW Hagedorn, M TI Overcoming a permeability barrier by microinjecting cryoprotectants into zebrafish embryos (Brachydanio rerio) SO CRYOBIOLOGY LA English DT Article DE cryopreservation; teleosts; zebrafish; cryoprotectants; yolk syncytial layer; vitrification; propylene glycol; dimethyl sulfoxide; formamide; acetamide ID MOUSE EMBRYOS; FISH EMBRYOS; VITRIFICATION; CRYOPRESERVATION; TOXICITY; SENSITIVITY; BLASTOCYSTS; SURVIVAL; ENZYMES; OOCYTES AB The goal of this research was to examine the developmental effects on zebrafish embryos (Brachydanio rerio) when cryoprotectants were directly microinjected into the yolk. Our objectives were to: (i) determine the final concentration of propylene glycol (PG) and dimethyl sulfoxide (Me(2)SO) that the embryos could tolerate without causing teratogenic effects; (ii) determine if the toxicity of Me(2)SO could be reduced by the simultaneous presence of various proportions of amides; and (iii) examine whether this intracellular cryoprotectant incorporation could reduce the cryodamage to the yolk syncytial layer (YSL) after vitrification trials. The rationale for conducting these microinjection experiments was to overcome the permeability barrier of the YSL. Intracellular PG produced better survival than Me(2)SO (P < 0.05). Embryos tolerated both 10- and 30-nl microinjections of PC, yielding final concentrations of 2.3 and 5.0 M within the yolk, resulting in 70 +/- 3 and 35 +/- 4% survival at day 5, respectively. In similar experiments with Me(2)SO, survival was lower than PG at 60 +/- 4 and 14 +/- 4% at 2.4 and 52 M. Unlike other cellular systems, the presence of amides, specifically acetamide or formamide, did not reduce the toxicity of Me(2)SO in zebrafish embryos (P 5 0.05). During vitrification trials, we estimated a 25% dehydration of the yolk, yielding an effective PC concentration of 5.9 M. However, the incorporation of this vitrifiable concentration of PG was not sufficient to improve the postthaw morphology of the YSL (P > 0.05). Clearly, other factors need to be examined in establishing a successful vitrification protocol for zebrafish embryos. (C) 2000 Academic Press. C1 Smithsonian Inst, Natl Zool Pk, Washington, DC 20008 USA. Smithsonian Inst, Conservat & Res Ctr, Washington, DC 20008 USA. Indiana Univ Purdue Univ, Dept Phys, Indianapolis, IN 46202 USA. RP Janik, M (reprint author), Smithsonian Inst, Natl Zool Pk, Washington, DC 20008 USA. FU NCRR NIH HHS [R01 RR08769] NR 38 TC 40 Z9 46 U1 2 U2 10 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0011-2240 J9 CRYOBIOLOGY JI Cryobiology PD AUG PY 2000 VL 41 IS 1 BP 25 EP 34 DI 10.1006/cryo.2000.2261 PG 10 WC Biology; Physiology SC Life Sciences & Biomedicine - Other Topics; Physiology GA 362DT UT WOS:000089763900004 PM 11017758 ER PT J AU Boese, KC AF Boese, KC TI Evaluating libraryland topics in periodicals databases SO ECONTENT LA English DT Article C1 Smithsonian Inst Lib, Washington, DC 20560 USA. RP Boese, KC (reprint author), Smithsonian Inst Lib, 10th & Constitut NW, Washington, DC 20560 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU ONLINE INC PI WILTON PA 213 DANBURY RD, WILTON, CT 06897-4007 USA SN 1525-2531 J9 ECONTENT JI Econtent PD AUG-SEP PY 2000 VL 23 IS 4 BP 57 EP 61 PG 5 WC Information Science & Library Science SC Information Science & Library Science GA 340JB UT WOS:000088528400015 ER PT J AU Gottlieb, CA Apponi, AJ McCarthy, MC Thaddeus, P Linnartz, H AF Gottlieb, CA Apponi, AJ McCarthy, MC Thaddeus, P Linnartz, H TI The rotational spectra of the HCCCNH+, NCCNH+, and CH3CNH+ ions SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID COOLED MOLECULAR-IONS; MILLIMETER-WAVE SPECTROSCOPY; CYCLOPROPENYL CATION; FREE-RADICALS; HNCCN+; DISCHARGE; CHEMISTRY; MICROWAVE; HC3NH+ AB The rotational spectra of the HCCCNH+, NCCNH+, and CH3CNH+ ions have been observed in a supersonic molecular beam by Fourier transform microwave (FTM) spectroscopy. The rotational and centrifugal distortion constants were determined for all three, and the nitrogen quadrupole hyperfine coupling constants for HCCCNH+ and NCCNH+. From the respective Doppler shifts, it is found that the velocities of the ions are 3% larger than those of the parent unprotonated molecules, and the linewidths are greater by about 50%. The concentration of the ions near the nozzle is approximately 10(11) cm(-3), which is sufficiently high to be detectable in the visible and the IR by present laser techniques. (C) 2000 American Institute of Physics. [S0021-9606(00)01829-8]. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Univ Basel, Inst Phys Chem, CH-4056 Basel, Switzerland. RP Gottlieb, CA (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 35 TC 40 Z9 40 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 1 PY 2000 VL 113 IS 5 BP 1910 EP 1915 DI 10.1063/1.481994 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 335XB UT WOS:000088269400032 ER PT J AU Reid, JW Ishida, T AF Reid, JW Ishida, T TI Itocyclops, a new genus proposed for Speocyclops yezoensis (Copepoda : Cyclopoida : Cyclopidae) SO JOURNAL OF CRUSTACEAN BIOLOGY LA English DT Article ID PUERTO-RICO; USA; SOUTHEASTERN; CRUSTACEA AB We redescribe Speocyclops yezoensis Ito on the basis of specimens from Japan and from Alaska and Tennessee, U.S.A. The combination of the segmentation of the swimming legs; the lack of dimorphism in the structure of the swimming legs, except for the modified terminal spine of the leg 3 endopodite in the males of some populations; the partly fused proximal segment of leg 5; and, in the female, the peculiar structure of the seminal receptacle provide grounds to propose a new genus Itocyclops to accommodate this taxon. A new record from Tennessee is the first from the eastern U.S.A. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. RP Reid, JW (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. NR 40 TC 12 Z9 12 U1 0 U2 0 PU CRUSTACEAN SOC PI SAN ANTONIO PA 840 EAST MULBERRY, SAN ANTONIO, TX 78212 USA SN 0278-0372 J9 J CRUSTACEAN BIOL JI J. Crustac. Biol. PD AUG PY 2000 VL 20 IS 3 BP 589 EP 596 DI 10.1651/0278-0372(2000)020[0589:IANGPF]2.0.CO;2 PG 8 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 341ZJ UT WOS:000088620600020 ER PT J AU Schnitzer, SA Dalling, JW Carson, WP AF Schnitzer, SA Dalling, JW Carson, WP TI The impact of lianas on tree regeneration in tropical forest canopy gaps: evidence for an alternative pathway of gap-phase regeneration SO JOURNAL OF ECOLOGY LA English DT Article DE species diversity; forest succession; canopy dynamics; Barro Colorado Island; Panama ID PLANT-SPECIES-DIVERSITY; NEOTROPICAL FOREST; ARRESTED SUCCESSION; RAIN-FOREST; NATIONAL-PARK; GROWTH; RECRUITMENT; SEEDLINGS; DYNAMICS; PANAMA AB 1 Regeneration in forest canopy gaps is thought to lead invariably to the rapid recruitment and growth of trees and the redevelopment of the canopy. Our observations, however, suggest that an alternate successional pathway is also likely, whereby gap-phase regeneration is dominated by lianas and stalled in a low-canopy state for many years. We investigated gap-phase regeneration in an old-growth tropical forest on Barro Colorado Island (BCI) in Panama to test the following two hypotheses: (i) many gaps follow a pathway in which they remain at a low canopy height and are dominated by lianas and (ii) the paucity of trees in this pathway is a function of liana density. 2 We surveyed a total of 428 gaps of varying ages (c. 5, c. 10, and 13+ years old) and identified those which followed the conventional pathway of regeneration and others that remained stalled in a low-canopy state for many years and were dominated by either lianas or palms. Each of these pathways will likely have different successional trajectories that will favour the growth of a distinct suite of mature species and ultimately result in contrasting species composition. 3 The successional pathway of liana-dominated, stalled gaps is common throughout the forest. We estimate conservatively that 7.5% of the gaps that form each year will follow this pathway, probably due to the suppression of tree regeneration by lianas, and that many of these stalled gaps will persist for much longer than 13 years. Consequently, a high proportion of gaps in the forest at any given time will be stalled. Furthermore, liana tangles, which persist in the tropical forest understorey for extended periods of time, almost certainly originate in these gaps. 4 Liana abundance was positively correlated with pioneer tree abundance and diversity while negatively correlated with non-pioneer tree abundance and diversity. Thus, lianas appear to inhibit non-pioneer tree survival while indirectly enhancing that of pioneer trees. 5 Lianas are abundant in many types of tropical and temperate forests and a successional pathway involving liana-dominated, stalled gaps may therefore be frequent and widespread. C1 Univ Pittsburgh, Dept Biol Sci, Pittsburgh, PA 15260 USA. Smithsonian Trop Res Inst, Balboa, Panama. RP Schnitzer, SA (reprint author), Univ Pittsburgh, Dept Biol Sci, Pittsburgh, PA 15260 USA. RI Carson, Walter/A-2569-2013; OI Schnitzer, Stefan/0000-0002-2715-9455 NR 79 TC 225 Z9 257 U1 0 U2 45 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0022-0477 J9 J ECOL JI J. Ecol. PD AUG PY 2000 VL 88 IS 4 BP 655 EP 666 DI 10.1046/j.1365-2745.2000.00489.x PG 12 WC Plant Sciences; Ecology SC Plant Sciences; Environmental Sciences & Ecology GA 347QT UT WOS:000088941200010 ER PT J AU Kharchenko, V Dalgarno, A AF Kharchenko, V Dalgarno, A TI Spectra of cometary X rays induced by solar wind ions SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID EXTREME-ULTRAVIOLET EMISSION; SELECTIVE ELECTRON-CAPTURE; C/1996 B2 HYAKUTAKE; SLOW COLLISIONS; DUST PARTICLES; HEAVY-IONS; HALE-BOPP; GENERATION; HE; PRECIPITATION AB The X-ray and extreme ultraviolet spectra produced by solar wind ions undergoing change transfer collisions with the atoms and molecules present in the atmospheres of comets are calculated. The calculations take account of the cascading transitions that follow electron capture into highly excited states. It is shown that sequential collisions cause the X-ray spectrum from the cometary center to be softer than that of the peripheral regions. Some of the brightest lines arise from forbidden transitions of helium-like oxygen and carbon ions. The X-ray luminosities and averaged spectra reflect the composition of the solar wind. The calculated luminosities and spectra corresponding to a typical distribution of impinging solar wind ions are consistent with observations of comets Hyakutake and Hale-Bopp. The spectral resolution required to establish charge transfer as the source of cometary X rays is discussed; an energy resolution of 10 eV should be adequate. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Kharchenko, V (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM vkharchenko@cfa.harvard.edu; adalgarno@cfa.harvard.edu NR 46 TC 83 Z9 84 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 1 PY 2000 VL 105 IS A8 BP 18351 EP 18359 DI 10.1029/1999JA000203 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 342RU UT WOS:000088659600015 ER PT J AU Balakrishnan, N Sergueeva, E Kharchenko, V Dalgarno, A AF Balakrishnan, N Sergueeva, E Kharchenko, V Dalgarno, A TI Kinetics and thermalization of hot N(S-4) atoms in the upper atmosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID THERMOSPHERIC NITRIC-OXIDE; FAST NITROGEN-ATOMS; NIGHTTIME TERRESTRIAL THERMOSPHERE; POTENTIAL-ENERGY SURFACE; SOFT X-RAYS; RATE CONSTANTS; ODD NITROGEN; COLLISIONS; NO; MODEL AB The production of energetic N(S-4) atoms and their subsequent thermalisation by collisions with the ambient gas play an important role in the heat and energy balance of the thermosphere. It has been suggested that nitric oxide formation by the reaction of energetic nitrogen atoms with O-2 may account for the NO deficiency in atmospheric models at altitudes of 105-110 km. Using calculated differential scattering cross sections for thermalization of N(S-4) atoms by elastic and inelastic collisions with atmospheric bath gases, we determine the energy distribution function of N(S-4) atoms and evaluate the importance of the N(S-4)+O-2 reaction as a source of NO in the thermosphere. We show that the nonthermal component produces large increases in the effective rate coefficient at low altitudes. However, we find that at altitudes below 130 km, where the production of NO by energetic N(S-4) atoms substantially exceeds the production by the thermal N(S-4) component, there is still a larger contribution from N(D-2) atoms, whereas at higher altitudes, where the N(D-2) atom source is smaller than the N(S-4) atom source, it is the thermal component of the N(S-4) distribution that dominates. Thus the production of NO by the reactions of energetic N(S-4) atoms cannot be invoked to explain the high abundance of NO. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Univ Virginia, Sch Engn & Appl Sci, Charlottesville, VA 22903 USA. RP Balakrishnan, N (reprint author), Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, 60 Garden St, Cambridge, MA 02138 USA. NR 31 TC 15 Z9 15 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 1 PY 2000 VL 105 IS A8 BP 18549 EP 18555 DI 10.1029/1999JA000296 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 342RU UT WOS:000088659600030 ER PT J AU McCulloch, S Boness, DJ AF McCulloch, S Boness, DJ TI Mother-pup vocal recognition in the grey seal (Halichoerus grypus) of Sable Island, Nova Scotia, Canada SO JOURNAL OF ZOOLOGY LA English DT Article DE grey seals; Halichoerus grypus; vocal recognition ID HARBOR SEAL; INDIVIDUAL VARIATION; PHOCA-VITULINA; SITE FIDELITY; NORTH-RONA; VOCALIZATIONS; INVESTMENT; DISPERSION; BEHAVIOR; SCOTLAND AB Parental recognition of offspring would be expected to evolve among densely populated species in which parental investment is large, and separations of the mother-pup pair are frequent. Although otariids present a well-developed system of mutual vocal recognition, evidence in phocids is weak. Furthermore, allo-suckling is prevalent in some species and may reflect confusion over the identity of pups. The vocalizations of grey seal Halichoerus grypus pups have been found to be stereotyped and individually distinctive on the Isle of May, Scotland. However, playback experiments showed that mothers fail to discriminate between the vocalizations of their pup and a non-filial pup. Moreover, widespread allo-suckling was observed. In contrast, grey seals on Sable Island, Nova Scotia, a population reproductively isolated from that of the Isle of May, show very little allo-suckling. This may reflect the presence of a recognition system that does not seem to be present on the Isle of May. During the 1999 breeding season on Sable Island, vocalizations of grey seal pups were recorded and playback experiments carried out to determine whether female grey seals respond differently to the playback of vocalizations of their own pup, a familiar pup and an unfamiliar pup. Grey seal mothers were found to make significantly more head turns and body movements towards the loudspeaker during the playback of their own pup call than during the playback of a familiar or unfamiliar pup call. In addition, there was no evidence of an effect of pup age. This suggests that female grey seals can discriminate between pup calls using the stereotyped and individually distinctive vocalizations of their pup, and that different selective pressures may be in operation between the Sable Island and Isle of May colonies. C1 Univ St Andrews, Sch Biol, St Andrews KY16 9TS, Fife, Scotland. Smithsonian Inst, Natl Zool Pk, Dept Zool Res, Washington, DC 20008 USA. RP McCulloch, S (reprint author), Univ St Andrews, Sch Biol, St Andrews KY16 9TS, Fife, Scotland. NR 35 TC 25 Z9 26 U1 2 U2 13 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0952-8369 J9 J ZOOL JI J. Zool. PD AUG PY 2000 VL 251 BP 449 EP 455 DI 10.1111/j.1469-7998.2000.tb00800.x PN 4 PG 7 WC Zoology SC Zoology GA 357NA UT WOS:000089506700004 ER PT J AU Riley, S AF Riley, S TI The flip side of sin. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst, Lib, Washington, DC 20560 USA. RP Riley, S (reprint author), Smithsonian Inst, Lib, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD AUG PY 2000 VL 125 IS 13 BP 159 EP 159 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA 347AP UT WOS:000088904300393 ER PT J AU Dzierzega, K Volz, U Nave, G Griesmann, U AF Dzierzega, K Volz, U Nave, G Griesmann, U TI Accurate transition rates for the 5p-5s transitions in KrI SO PHYSICAL REVIEW A LA English DT Article ID RADIATIVE LIFETIMES; PROBABILITIES; DEACTIVATION; STATES AB Branching fractions were measured for electric-dipole transitions from the 5p upper levels to the 5s levels in neutral krypton atoms. The measurements were made with a wall-stabilized electric are and a 2-m monochromator for the spectral lines in the visible, and with a hollow cathode lamp and the NIST 2-m Fourier-transform spectrometer for the lines in the near infrared. A semiempirical calculation, based on accurately known lifetimes for six upper levels, was used to calculate lifetimes for which accurate measurements do not exist. This resulted in a complete set of lifetimes for all 5p levels. Branching fractions and lifetimes were used to calculate transition rates for the 5p-5s transitions. The relative uncertainties of the transition rates range from less than 1% for the strongest lines to about 10% for the weakest lines. Our data also reveal that most of the previous measurements appear to have been affected by opacity effects in the light sources. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Jagiellonian Univ, Inst Fizyki M Smoluchowskiego, PL-30059 Krakow, Poland. Univ Kaiserslautern, Fachbereich Phys, D-67653 Kaiserslautern, Germany. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 24 TC 14 Z9 14 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 2000 VL 62 IS 2 AR 022505 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 343CD UT WOS:000088683400043 ER PT J AU Sautenkov, VA Lukin, MD Bednar, CJ Novikova, I Mikhailov, E Fleischhauer, M Velichansky, VL Welch, GR Scully, MO AF Sautenkov, VA Lukin, MD Bednar, CJ Novikova, I Mikhailov, E Fleischhauer, M Velichansky, VL Welch, GR Scully, MO TI Enhancement of magneto-optic effects via large atomic coherence in optically dense media SO PHYSICAL REVIEW A LA English DT Article ID ELECTROMAGNETICALLY INDUCED TRANSPARENCY; INTENSE LASER FIELDS; NONLINEAR FARADAY; SAMARIUM VAPOR; GROUP-VELOCITY; GAS; ROTATION; LIGHT; INTERFERENCE; RESONANCE AB We utilize the generation of large atomic coherence in optically dense media to enhance the resonant nonlinear magneto-optic effect by several orders of magnitude, thereby eliminating power broadening and improving the fundamental signal-to-noise ratio. A proof-of-principle experiment is carried out in a dense vapor of Rb atoms. Applications such as optical magnetometry, the search for Violations of parity and time-reversal symmetry, and nonlinear optics at low light levels are feasible. C1 Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. Harvard Smithsonian Ctr Astrophys, ITAMP, Cambridge, MA 02138 USA. Max Planck Inst Quantum Opt, D-85748 Garching, Germany. PN Lebedev Phys Inst, Moscow 117924, Russia. RP Sautenkov, VA (reprint author), Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. RI Novikova, Irina/B-9041-2008; Fleischhauer, Michael/G-6716-2011; Velichansky, Vladimir/M-4861-2015; Sautenkov, Vladimir/N-7024-2013 OI Sautenkov, Vladimir/0000-0001-8400-9405 NR 31 TC 55 Z9 56 U1 2 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 2000 VL 62 IS 2 AR 023810 DI 10.1103/PhysRevA.62.023810 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 343CD UT WOS:000088683400105 ER PT J AU Segev, B Milonni, PW Babb, JF Chiao, RY AF Segev, B Milonni, PW Babb, JF Chiao, RY TI Quantum noise and superluminal propagation SO PHYSICAL REVIEW A LA English DT Article ID INFORMATION-TRANSFER; OPTICAL PULSES; SUPERFLUORESCENCE; MEDIA; AMPLIFIERS; LIGHT; DELAY AB Causal "superluminal" effects have recently been observed and discussed in various contexts. The question arises whether such effects could be observed with extremely weak pulses, and what would prevent the observation of an "optical tachyon." Aharonov, Reznik, and Stern (ARS) [Phys. Rev. Lett. 81, 2190 (1998)] have argued that quantum noise will preclude the observation of a superluminal group velocity when the pulse consists of one or a few photons. In this paper we reconsider this question both in a general framework and in the specific example, suggested by Chiao, Kozhekin, and Kurizki (CKK) [Phys. Rev. 77, 1254 (1996)], of off-resonant, short-pulse propagation in an optical amplifier. We derive in the case of the amplifier a signal-to-noise ratio that is consistent with the general ARS conclusions when we impose their criteria for distinguishing between superluminal propagation and propagation at the speed c. However, results consistent with the semiclassical arguments of CKK an obtained if weaker criteria are imposed, in which case the signal can exceed the noise without being "exponentially large." We show that the quantum fluctuations of the field considered by ARS are closely related to superfluorescence noise. More generally, we consider the implications of unitarity for superluminal propagation and quantum noise and study, in addition to the complete and truncated wave packets considered by ARS, the residual wave packet formed by their difference. This leads to the conclusion that the noise is mostly luminal and delayed with respect to the superluminal signal. In the limit of a very weak incident signal pulse, the superluminal signal will be dominated by the noise part, and the signal-to-noise ratio will therefore be very small. C1 Ben Gurion Univ Negev, Dept Chem, IL-84105 Beer Sheva, Israel. Univ Calif Los Alamos Natl Lab, Theoret Div T 4, Los Alamos, NM 87545 USA. Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Segev, B (reprint author), Ben Gurion Univ Negev, Dept Chem, POB 653, IL-84105 Beer Sheva, Israel. NR 19 TC 15 Z9 15 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 2000 VL 62 IS 2 AR 022114 DI 10.1103/PhysRevA.62.022114 PG 15 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 343CD UT WOS:000088683400021 ER PT J AU Vardi, A Shapiro, M AF Vardi, A Shapiro, M TI Matter-field entropy transfer in stimulated photoassociation SO PHYSICAL REVIEW A LA English DT Article ID ULTRACOLD MOLECULES; ATOMS; CONTINUUM; APPROXIMATION; MECHANISM; LI-7(2) AB We study the quantum statistics of stimulated photoassociation, using system-reservoir dynamics. We show that, contrary to "common wisdom," spontaneous emission is nest the only mechanism by which entropy loss from a material system to a radiation field can occur. By formally treating die matter waves as the hath and the stimulating radiation field as the system, we an able to derive a Lindblad-type equation for the time dependence of the reduced radiation density matrix and show that entropy exchange between matter and radiation in stimulated photoassociation is indeed possible. C1 Harvard Smithsonian Ctr Astrophys, ITAMP, Cambridge, MA 02138 USA. Weizmann Inst Sci, Dept Chem Phys, IL-76100 Rehovot, Israel. RP Vardi, A (reprint author), Harvard Smithsonian Ctr Astrophys, ITAMP, 60 Garden St,MS14, Cambridge, MA 02138 USA. RI Vardi, Amichay/D-8189-2011 OI Vardi, Amichay/0000-0002-8992-2129 NR 25 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD AUG PY 2000 VL 62 IS 2 AR 025401 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 343CD UT WOS:000088683400121 ER PT J AU Whipple, FL AF Whipple, FL TI Oort-Cloud and Kuiper-Belt comets SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT 7th International Asteroids, Comets, Meteors Conference (ACM 99) CY JUL 26-30, 1999 CL CORNELL UNIV, ITHACA, NEW YORK HO CORNELL UNIV ID SHORT-PERIOD COMETS; 17 COMETS AB This is a study of the magnitude variation of 93 Kuiper-Belt (KB) comets of short period and 77 Oort-Cloud (OC) comets, including 14 Halley-type. Two criteria of their activity show consistently that the Kuiper-Belt comets are more active at large solar distances than the Oort-Cloud comets. This result is consistent with the expectation that the KB comets were formed at lower temperatures, farther from the Sun, than the OC comets, and contain more ices that can freeze only at lower temperatures. The result is supported by the fact that the comets in the oldest KB age class act like the OC comets, suggesting that the cores of very old KB comets have been heated by radioactivity and lost their more volatile ices, most of the remaining ice being water ice. The degree to which spectroscopic data by A'Hearn ct al. (1995. Icarus 118, 223-270) support the result of this study is discussed. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Whipple, FL (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 17 TC 3 Z9 3 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD AUG PY 2000 VL 48 IS 10 BP 1011 EP 1019 DI 10.1016/S0032-0633(00)00070-2 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 370HQ UT WOS:000165117800018 ER PT J AU Florescu, V Gavrila, M AF Florescu, V Gavrila, M TI Soft-photon emission in extreme-relativistic Compton scattering by K-shell electrons and connection to photoeffect SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article; Proceedings Paper CT Symposium on High Energy Interactions of Photons and Electrons with Atoms, A Retrospective of the Work of Richard Pratt CY OCT 30, 1999 CL UNIV PITTSBURGH, PITTSBURGH, PENNSYLVANIA HO UNIV PITTSBURGH DE relativistic K-shell; Compton effect; infrared divergence; relativistic K-shell photoeffect ID APPROXIMATION AB We have recently obtained cross-sections for Compton scattering by K-shell electrons at extreme-relativistic (ER) energies of the incoming photon. Our method is essentially analytical, and only at the end did it require a modest numerical computation. The results are valid for the Compton line of the scattered photon spectrum, but do not cover the infrared divergence at the soft-photon end of the spectrum. This case is treated in the present paper. The method we apply here is an adaptation of the one used for the Compton line. This allows us to make use of many previous results. The quadruply and doubly differential Compton cross-sections can be expressed in analytical forms which allow factorization of the ER photoeffect cross-sections (differential or total, respectively). This result is shown to be a manifestation of the soft-photon theorem connecting the Compton matrix element at low emitted photon frequencies to that of the photoeffect. The computation of ER Compton cross-sections with soft-photon emission is thereby reduced to that of the cross-sections for the ER photoeffect. We carry out a computation for the latter case and extend previously existing results. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Univ Bucharest, Dept Phys, Bucharest, Romania. RP Gavrila, M (reprint author), Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, 60 Garden St, Cambridge, MA 02138 USA. RI FLORESCU, Viorica/A-2394-2014 NR 25 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-806X J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD AUG PY 2000 VL 59 IS 2 BP 127 EP 136 DI 10.1016/S0969-806X(00)00282-6 PG 10 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA 340HR UT WOS:000088527500003 ER PT J AU Deng, YY Schmieder, B Engvold, O DeLuca, E Golub, L AF Deng, YY Schmieder, B Engvold, O DeLuca, E Golub, L TI Emergence of sheared magnetic flux tubes in an active region observed with the SVST and TRACE SO SOLAR PHYSICS LA English DT Article ID TRANSITION REGION; CORONAL EXPLORER; PHOTOSPHERE; FIELDS AB The active region NOAA AR 8331 was a target of an international ground-based observational campaign in the Canaries and coordinated with space instruments (TRACE and Yohkoh). We focus our study on observations obtained with the SVST at LaPalma, and with TRACE. On 10 September 1998, arch-filament systems were observed with high spatial and temporal resolution, from the lower to the upper atmosphere of the Sun, during five hours. Flux tubes emerged with increasing shear, which apparently led to energy release and heating in the overlying corona. A model for filament formation by the emergence of U-shaped loops from the subphotosphere, as proposed by Rust and Kumar (1994), is supported by the present observations. The coronal response to these events is visualized by rising, medium-scale loop brightenings. The low-lying X-ray loops show short-lived, bright knots which are thought to result from interaction between different loop systems. C1 Chinese Acad Sci, Natl Astron Observ, Beijing Astron Observ, Beijing 100012, Peoples R China. Observ Paris, Sect Meudon, F-92195 Meudon, France. Univ Oslo, Inst Astrophys, Blindern, Norway. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. RP Deng, YY (reprint author), Chinese Acad Sci, Natl Astron Observ, Beijing Astron Observ, Beijing 100012, Peoples R China. NR 21 TC 15 Z9 15 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD AUG PY 2000 VL 195 IS 2 BP 347 EP 366 DI 10.1023/A:1005299227675 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 366UP UT WOS:000090023200008 ER PT J AU de Queiroz, K AF de Queiroz, K TI The definitions of taxon names: a reply to Stuessy SO TAXON LA English DT Editorial Material ID PHYLOGENETIC DEFINITIONS C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Vertebrate Zool, Washington, DC 20560 USA. RP de Queiroz, K (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Vertebrate Zool, Washington, DC 20560 USA. NR 11 TC 15 Z9 15 U1 0 U2 0 PU INT ASSOC PLANT TAXONOMY PI BERLIN PA BOTANISCHER GARTEN BOTANISCHES MUSEUM BERLIN-DAHLEM, KONIGIN-LUISE-STRABE 6-8, D-14191 BERLIN, GERMANY SN 0040-0262 J9 TAXON JI Taxon PD AUG PY 2000 VL 49 IS 3 BP 533 EP 536 DI 10.2307/1224349 PG 4 WC Plant Sciences; Evolutionary Biology SC Plant Sciences; Evolutionary Biology GA 351XK UT WOS:000089184600011 ER PT J AU Nicolson, DH AF Nicolson, DH TI A new online bibliographic database of proposals for conservation and rejection of botanical names SO TAXON LA English DT Article DE database; nomenclature; proposals AB As of mid-2000 over 4,400 proposals have been made to conserve and/or reject botanical names, almost all at the rank of family, genus or species. Information on all proposals has been compiled, including the author and places of publication of each proposal, as well as the place of publication of the report on the proposals by the Committees for particular groups, the General Committee report, where cited in a Synopsis of Proposals, where ratified by a Congress, and where each of the approved proposals first appeared in a Code. With nearly 3000 of these names already in the Code the success rate of proposals approaches two-thirds. This compiled information is accessible and searchable online: . C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, Washington, DC 20560 USA. RP Nicolson, DH (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, MRC-166, Washington, DC 20560 USA. NR 21 TC 3 Z9 3 U1 0 U2 0 PU INT ASSOC PLANT TAXONOMY PI BERLIN PA BOTANISCHER GARTEN BOTANISCHES MUSEUM BERLIN-DAHLEM, KONIGIN-LUISE-STRABE 6-8, D-14191 BERLIN, GERMANY SN 0040-0262 J9 TAXON JI Taxon PD AUG PY 2000 VL 49 IS 3 BP 549 EP 554 DI 10.2307/1224354 PG 6 WC Plant Sciences; Evolutionary Biology SC Plant Sciences; Evolutionary Biology GA 351XK UT WOS:000089184600016 ER PT J AU Olson, SL Wingate, DB AF Olson, SL Wingate, DB TI Two new species of flightless rails (Aves : Rallidae) from the Middle Pleistocene "crane fauna" of Bermuda SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article ID QUATERNARY STRATIGRAPHY; BAHAMAS AB Two new species of flightless rails are described from a Pleistocene fauna in Bermuda that also includes an extinct crane (Cnrs latipes) and an extinct duck (Anas pachyscelus). The medium-sized Rallus ibycus, new species, was possibly derived from North American populations of Virginia Rail (R. limicola), but had a longer bill, much more robust legs, and reduced wings and pectoral girdle. The very small Porzana piercei, new species, except for the reduced wing and pectoral girdle, is very similar to the extant Yellow-breasted Crake (P. flaviventer), which now occurs only in the Neotropics, including the Greater Antilles. The fauna that included these rails developed during a long, stable glacial period of lowered sea-levels in the Middle Pleistocene, during which the entire Bermuda platform was emergent. This was followed by an abrupt and extreme interglacial about 400,000 years ago when sea-levels rose to 21 m above present levels, obliterating most of Bermuda and much of its endemic fauna, including the rails. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Vertebrate Zool, Washington, DC 20560 USA. Bermuda Nat Hist Museum, Flatts, Bermuda. RP Olson, SL (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Vertebrate Zool, Washington, DC 20560 USA. NR 18 TC 16 Z9 16 U1 0 U2 1 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD JUL 31 PY 2000 VL 113 IS 2 BP 356 EP 368 PG 13 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 341TQ UT WOS:000088606000002 ER PT J AU Anderson, WD Baldwin, CC AF Anderson, WD Baldwin, CC TI A new species of Anthias (Teleostei : Serranidae : Anthiinae) from the Galapagos Islands, with keys to Anthias and eastern Pacific Anthiinae SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article ID SOUTH-PACIFIC; PISCES; MORPHOLOGY; FISH; HERMAPHRODITISM; HYPOPLECTRODES; ELLERKELDIA; SCALES; GENUS; PERCH AB Anthias noeli, new species, is described from 17 specimens collected off the Galapagos Islands in the eastern Pacific, keys to the species of Anthias and to the species of eastern Pacific Anthiinae are provided, and comments are presented on hermaphroditism in the Anthiinae. The specimens of the new species, described herein, constitute the first authentic record of Anthias from the Pacific; the genus is otherwise known only from the Atlantic where it is represented by seven species. The following characters in combination allow the separation of Anthias noeli from its congeners: soft rays in the dorsal fin 15 (rarely 16); tubed lateral-line scales 38 to 46; caudal-peduncle scales 22 to 25; lower jaw naked or with only a few scales posteriorly; gular region naked; total gillrakers on first gill. arch 37 to 41; dorsal, anal, pelvic, and caudal fins each with some produced soft rays; anal fin angulate posteriorly; depressed anal-fin length 32 to 43% SL; longest dorsal-fin spine (fourth or fifth) 14 to 20% SL; upper caudal-fin lobe (39-60% SL) longer than lower (38-57% SL); no teeth on tongue. C1 Coll Charleston, Grice Marine Biol Lab, Charleston, SC 29412 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Vertebrate Zool, Washington, DC 20560 USA. RP Anderson, WD (reprint author), Coll Charleston, Grice Marine Biol Lab, 205 Fort Johnson, Charleston, SC 29412 USA. NR 52 TC 9 Z9 11 U1 0 U2 1 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD JUL 31 PY 2000 VL 113 IS 2 BP 369 EP 385 PG 17 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 341TQ UT WOS:000088606000003 ER PT J AU Harrison-Nelson, E Kornicker, LS AF Harrison-Nelson, E Kornicker, LS TI Euphilomedes cooki, a new species of myodocopid ostracode from Moreton Bay, SE Queensland, Australia SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article AB A new species of myodocopid ostracode in the subfamily Philomedinae from Moreton Bay, S.E. Queensland, Australia, is described and illustrated. A key is presented to the ten known species of Euphilomedes having primary furcal claws 1, 2, 4, and 6. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. RP Harrison-Nelson, E (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. NR 18 TC 1 Z9 4 U1 1 U2 3 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD JUL 31 PY 2000 VL 113 IS 2 BP 465 EP 479 PG 15 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 341TQ UT WOS:000088606000013 ER PT J AU Lu, H Fauchald, K AF Lu, H Fauchald, K TI Ophryotrocha lipscombae, a new species and a possible connection between ctenognath and labidognath-prionognath eunicean worms (Polychaeta) SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article ID DORVILLEIDAE ANNELIDA; GENERIC REVISION; EUNICIDA; GENUS AB One new species of dorvilleid, Ophryotrocha lipscombae, is described based on material from the U.S. Atlantic slope. This new species is unique in its presence of 5 pairs of accessory plates, which are never found in any other dorvilleids, but are present in all labidognath-prionognath euniceans. A brief discussion of the phylogenetic position of Ophryotrocha lipscombae in the Eunicida is provided. C1 George Washington Univ, Dept Biol Sci, Washington, DC 20052 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. RP Lu, H (reprint author), George Washington Univ, Dept Biol Sci, Washington, DC 20052 USA. NR 15 TC 7 Z9 7 U1 1 U2 3 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD JUL 31 PY 2000 VL 113 IS 2 BP 486 EP 492 PG 7 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 341TQ UT WOS:000088606000015 ER PT J AU Falcon, LI Vecchione, M Roper, CFE AF Falcon, LI Vecchione, M Roper, CFE TI Paralarval gonatid squids (Cephalopoda : Oegopsida) from the Mid-North Atlantic Ocean SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article AB Ninety six gonatid cephalopod specimens (Oegopsida: Gonatidae) from the University of Amsterdam Mid-North Atlantic Plankton Expeditions were analyzed and two species were identified: Gonatus steenstrupi (Kristensen 1981) and Gonatus fabricii (Lichtenstein 1818). Gonatids were collected only in spring and summer, despite sampling in autumn and winter. This paper describes aspects of their development and reports their geographical distribution in the central North Atlantic Ocean. Chromatophore patterns were the most consistently useful characters for distinguishing between the species. Among 34 measurements, Tentacle Length (TtL) relative to Dorsal Mantle Length (ML) and number of suckers on Arms I-IV were useful for distinguishing specimens >13 mm ML. Both species develop hooks from suckers on the arms and tentacular clubs at ML >20 mm. Subtle differences were noted in the morphology of the funnel pads except in the smallest specimens. Specimens of G. steenstrupi >20 mm ML were collected at greater depths (250 to 995 m) than the smaller specimens (found at depths <200 m). Our data suggest that 20 mm ML is the point of transition between paralarvae and juveniles of G. steenstrupi, because specimens larger than 20 mm ML have well defined hooks, and a juvenile vertical distribution is established. C1 Univ Nacl Autonoma Mexico, Inst Ciencias Mar & Limnol, Mexico City 045510, DF, Mexico. Smithsonian Inst, Natl Museum Nat Hist, Res Training Program, Washington, DC 20560 USA. Natl Museum Nat Hist, Natl Systemat Lab, Natl Marine Fisheries Serv, Washington, DC 20560 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool Mollusks, Washington, DC 20560 USA. RP Falcon, LI (reprint author), Univ Nacl Autonoma Mexico, Inst Ciencias Mar & Limnol, Apdo Postal 70-305, Mexico City 045510, DF, Mexico. NR 13 TC 7 Z9 8 U1 0 U2 0 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD JUL 31 PY 2000 VL 113 IS 2 BP 532 EP 541 PG 10 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 341TQ UT WOS:000088606000020 ER PT J AU Harasewych, MG Kantor, YI Linse, K AF Harasewych, MG Kantor, YI Linse, K TI Parabuccinum, a new genus of Magellanic buccinulid (Gastropoda : Neogastropoda), with a description of a new species SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article AB A new genus, Parabuccinum, is established for four bathyal Magellanic species, of which one, Parabuccinum rauscherti, is described as new. The remaining three species were originally described in the Antarctic genus Chlanidota, from which they differ in the morphology of their protoconch, operculum, radula, stomach, and male reproductive system. Parabuccinum appears to be most closely related to the monotypic circumAntarctic genus Neobuccinum, but may be distinguished on the basis of shell and penis morphology, as well as by the size and shape of the gland of Leiblein. Parabuccinum is endemic to the Magellanic Province, and is the first record of the subfamily Bucinulinae in the malacofauna of this region. C1 Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. Russian Acad Sci, AN Severtzov Inst Problems Evolut, Moscow 117071, Russia. Univ Hamburg, Inst Zool, D-20146 Hamburg, Germany. Univ Hamburg, Zool Museum, D-20146 Hamburg, Germany. RP Harasewych, MG (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. RI Kantor, Yuri/D-5259-2014 OI Kantor, Yuri/0000-0002-3209-4940 NR 8 TC 5 Z9 6 U1 0 U2 0 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 USA SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD JUL 31 PY 2000 VL 113 IS 2 BP 542 EP 560 PG 19 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 341TQ UT WOS:000088606000021 ER PT J AU Insley, SJ AF Insley, SJ TI Long-term vocal recognition in the northern fur seal SO NATURE LA English DT Article ID FIDELITY AB The ability to recognize and remember individual identities for long periods of time has important implications for the evolution of animal social behaviour, particularly complex interactions such as cooperation or mate choice(1-7). Despite this importance, there is only a single example of long-term individual recognition in nature, the 8-month retention of neighbour's song among male hooded warblers, Wilsonia citrina(7), and there is none for a nonhuman mammal. Associations between individuals spanning years, which are especially prevalent in carnivores(8), primates(9) and seabirds(10,) and evidence of mate rdelity(11,12) provide indirect support for the ability of long-term recognition. In many of these instances, however, individuals do not separate for extended periods, and thus long-term recognition, although often assumed, may be both unnecessary and nonexistent. Furthermore, site fidelity rather than individual recognition may explain many instances of mate fidelity(10). Here I show that mother-offspring pairs of a migratory otariid pinniped-the northern fur seal (Callorhinus ursinus)-not only have the ability to recognize each other's vocalizations during the course of a breeding season, but are also able to retain these memories for at least 4 years. C1 Univ Calif Davis, Anim Behav Grp, Davis, CA 95616 USA. Smithsonian Inst, Natl Zool Pk, Dept Zool Res, Washington, DC 20008 USA. RP Insley, SJ (reprint author), Univ Calif Davis, Anim Behav Grp, Davis, CA 95616 USA. NR 18 TC 89 Z9 93 U1 5 U2 27 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD JUL 27 PY 2000 VL 406 IS 6794 BP 404 EP 405 DI 10.1038/35019064 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 337WC UT WOS:000088383800045 PM 10935635 ER PT J AU Alekseyev, AB Liebermann, HP Buenker, RJ Balakrishnan, N Sadeghpour, HR Cornett, ST Cavagnero, MJ AF Alekseyev, AB Liebermann, HP Buenker, RJ Balakrishnan, N Sadeghpour, HR Cornett, ST Cavagnero, MJ TI Spin-orbit effects in photodissociation of sodium iodide SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID RELATIVISTIC EFFECTIVE POTENTIALS; FEMTOSECOND LASER-PULSE; WAVE-PACKET MOTION; CONFIGURATION-INTERACTION; PREDISSOCIATION DYNAMICS; ENERGY EXTRAPOLATION; QUANTUM DYNAMICS; CI CALCULATIONS; NAI; DISSOCIATION AB Ab initio configuration interaction calculations of the electronic binding energies, spin-orbit coupling matrix elements and transition dipole moments of NaI are presented. The results are used to construct adiabatic and diabatic representations of the 0(+) molecular states relevant to predissociation. The dynamics of photopredissociation is elucidated by multichannel time-dependent wave packet propagation in the diabatic representation. Specific features associated with the spatial and temporal evolution of the wave packet are ascribed to those observed in femtosecond pump-probe experiments. In particular, the rate of decay of the electronically excited NaI* complex is found to be in close agreement with time-resolved experimental studies. Partial photoabsorption cross sections for the production of iodine atoms in the ground (P-2(3/2)) and excited (P-2(1/2)) spin-orbit states are calculated and found to peak at excitation wavelengths of 322 and 263 nm, respectively, in accord with experimental data. (C) 2000 American Institute of Physics. [S0021-9606(00)01228-9]. C1 Berg Univ Gesamthsch Wuppertal, Fachbereich Theoret Chem 9, D-42097 Wuppertal, Germany. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. RP Alekseyev, AB (reprint author), Berg Univ Gesamthsch Wuppertal, Fachbereich Theoret Chem 9, D-42097 Wuppertal, Germany. NR 38 TC 29 Z9 30 U1 1 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 22 PY 2000 VL 113 IS 4 BP 1514 EP 1523 AR PII [S0021-9606(00)01228-9] DI 10.1063/1.481938 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 333RJ UT WOS:000088144000025 ER PT J AU Dolan, JR AF Dolan, JR TI Tintinnid ciliate diversity in the Mediterranean Sea: longitudinal patterns related to water column structure in late spring-early summer SO AQUATIC MICROBIAL ECOLOGY LA English DT Article DE biodiversity; plankton; latitudinal gradient ID SOUTHERN-CALIFORNIA BIGHT; MICRO-ZOOPLANKTON; FUNCTIONAL-ROLE; GROWTH-RATES; GRAZING RATE; ABUNDANCE; PHYTOPLANKTON; CHLOROPHYLL; MORPHOLOGY; CILIOPHORA AB Globally, north-south gradients in diversity are well known, and in the world ocean they have been related to north-south gradients in water column structure. Here diversity in planktonic ciliates, both taxonomic and morphological, is explored in the Mediterranean Sea, which displays west-east gradients in the water column characteristics of chlorophyll concentrations and distributions. Tintinnids, which are loricate planktonic ciliates, were enumerated and identified in samples from 23 stations between 2 and 32 degrees E, obtained from the Catalan Sea in June 1993 and from a cross-Mediterranean transect in May-June 1996. From west to east, concentrations of tintinnids showed Little variability, while numbers of species and genera, as well as diversity indices (H' values), increased. These parameters were positively related to depths of the chlorophyll maximum layer and negatively correlated with chlorophyll concentrations. Corresponding to the west to east increases in diversity were increases in community averages of lorica oral diameter and overall length, again positively correlated to deepening of chlorophyll maximum depths, and negatively related to average chlorophyll concentrations. Morphological diversity was related to species diversity, not as variability in lorica oral diameters, but as variability in average lorica length. In the Mediterranean Sea, a gradient of taxonomic and morphological diversity is relatable to a specific feature of the water column, the depth of the chlorophyll maximum layer. Trophic specialization as a dominant mechanism underlying diversity was not supported by data on lorica oral diameters. C1 Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. CNRS, ESA 7076, Stn Zool, Marine Microbiol Ecol Grp, F-06230 Villefranche Sur Mer, France. RP Dolan, JR (reprint author), Smithsonian Environm Res Ctr, POB 28, Edgewater, MD 21037 USA. EM dolan@obs-vlfr.fr RI Dolan, John/A-4513-2009 OI Dolan, John/0000-0002-9454-1355 NR 63 TC 33 Z9 33 U1 0 U2 1 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0948-3055 EI 1616-1564 J9 AQUAT MICROB ECOL JI Aquat. Microb. Ecol. PD JUL 21 PY 2000 VL 22 IS 1 BP 69 EP 78 DI 10.3354/ame022069 PG 10 WC Ecology; Marine & Freshwater Biology; Microbiology SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Microbiology GA 341ZP UT WOS:000088621100006 ER PT J AU Patel, NA Greenhill, LJ Herrnstein, J Zhang, QZ Moran, JM Ho, PTP Goldsmith, PF AF Patel, NA Greenhill, LJ Herrnstein, J Zhang, QZ Moran, JM Ho, PTP Goldsmith, PF TI Proper motion of water masers associated with IRAS 21391+5802: Bipolar outflow and an AU-scale dusty circumstellar shell SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : jets and outflows; masers; stars : formation ID MOLECULAR OUTFLOWS; STAR-FORMATION; H2O MASERS; YOUNG STARS; DISTANCES; KINEMATICS; IC1396N AB We present Very Long Baseline Array (VLBA) observations of water maser emission associated with the star-forming region IRAS 21391+5802, which is embedded in a bright-rimmed cometary globule in IC 1396. The angular resolution of the maps is similar to 0.8 mas, corresponding to a spatial resolution of similar to 0.6 AU at an estimated distance of 750 pc. Proper motions are derived for 10 maser features identified consistently over three epochs, which were separated by intervals of about 1 month. The masers appear in four groups, which are aligned linearly on the sky, roughly along a northeast-southwest direction, with a total separation of similar to 520 AU (similar to 0 ".7). The three-dimensional velocities of the masers have a maximum value of similar to 42 km s(-1) (similar to 9 AU yr(-1)). The average error on the derived proper motions is similar to 4 km s(-1) The overall pattern of proper motions is indicative of a bipolar outflow. Proper motions of the masers in a central cluster, with a projected extent of similar to 20 AU, show systematic deviations from a radial outflow. However, we find no evidence of Keplerian rotation, as has been claimed elsewhere. A nearly circular loop of masers lies near the middle of the cluster. The radius of this loop is 1 AU, and the line-of-sight velocities of the masers in the loop are within 2 km s(-1) of the systemic velocity of the region. These masers presumably exist at the radial distance where significant dust condensation occurs in the outflow emanating from the star. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. Cornell Univ, Natl Astron & Ionosphere Ctr, Dept Astron, Ithaca, NY 14853 USA. RP Patel, NA (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM npatel@cfa.harvard.edu; lgreenhill@cfa.harvard.edu; jherrnstein@nrao.edu; qzhang@cfa.harvard.edu; jmmoran@cfa.harvard.edu; pho@cfa.harvard.edu; pfg@astrosun.tn.cornell.edu RI Goldsmith, Paul/H-3159-2016; OI Zhang, Qizhou/0000-0003-2384-6589 NR 24 TC 40 Z9 41 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 2000 VL 538 IS 1 BP 268 EP 274 DI 10.1086/309126 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 343MK UT WOS:000088706000028 ER PT J AU Li, J Kuhn, J LaBonte, B Raymond, JC Acton, LW AF Li, J Kuhn, J LaBonte, B Raymond, JC Acton, LW TI Global solar corona revealed by time series observations SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : corona; Sun : UV radiation; Sun : X-rays, gamma rays ID TEMPERATURE STRUCTURE; INTERPLANETARY SPACE; PHYSICAL-PROPERTIES; DENSITY STRUCTURE; HOLE; REGION; EIT; SPECTROMETER; TELESCOPE; STREAMERS AB Time series observations at UV (Extreme Ultraviolet Imaging Telescope/Solar and Heliospheric Observatory) and X-ray (Soft X-Ray Telescope/Yohkoh) wavelengths reveal properties of the global solar corona that are not easily identified in a single image. A median-filtering technique that rejects features varying with time is used to isolate background corona. The coronal hole boundaries, polar plumes, and polar rays in the inner corona are clearly seen in Extreme Ultraviolet Imaging Telescope data over 5 months during the last solar minimum (1996 January through May). For the first time, we provide physical evidence for coronal hole boundaries in the inner corona. The observations show clearly that the polar coronal holes expand divergently with height. A simple latitudinal and radial electron density distribution for the inner corona is found. C1 Inst Astron, Honolulu, HI 96822 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. RP Li, J (reprint author), Inst Astron, 2680 Woodlawn Dr, Honolulu, HI 96822 USA. EM jing@jfa.hawaii.edu NR 35 TC 11 Z9 11 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 2000 VL 538 IS 1 BP 415 EP 423 DI 10.1086/309110 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 343MK UT WOS:000088706000041 ER PT J AU Ake, TB Dupree, AK Young, PR Linsky, JL Malina, RF Griffiths, NW Siegmund, OHW Woodgate, BE AF Ake, TB Dupree, AK Young, PR Linsky, JL Malina, RF Griffiths, NW Siegmund, OHW Woodgate, BE TI Far Ultraviolet Spectroscopic Explorer observations of the active cool star AB Doradus SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : chromospheres; stars : flare; stars : individual (AB Doradus); stars : pre-main-sequence; ultraviolet : stars ID X-RAY OBSERVATIONS AB Far-ultraviolet spectra were obtained of the active cool star AB Doradus (HD 36705) during the calibration and checkout period of the Fur Ultraviolet Spectroscopic Explorer (FUSE) satellite. Observations in this early phase of the mission were taken at a resolving power of 12,000-15,000 (similar to 20-25 km s(-1)) and covered the spectral range 905-1187 Angstrom. The integrated spectrum exhibits strong, rotationally broadened stellar emission from C III (lambda lambda 977, 1175) and O VI (lambda lambda 1032, 1037) and many weaker lines. Strong emission lines of C III and O VI exhibit broad wings. The C III lambda 977 profile shows blueshifted absorption at similar to 30 km s(-1), and C II lambda 1036 absorption appears superposed on emission in the wing of O vr lambda 1037. Rotational modulation of C III and O VI is present, in harmony with its photometric variability. Flares were detected in the brightest lines, and subexposures were analyzed to examine flux and profile variations. Downflows that extend to 600 km s(-1) during a flare are found in the O VI profiles. These early observations demonstrate that FUSE will be an exceptional instrument for studying chromospheres in cool stars. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Comp Sci Corp, Lanham Seabrook, MD USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Gaithersburg, MD USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Ake, TB (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA. RI Woodgate, Bruce/D-2970-2012 NR 14 TC 24 Z9 24 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 2000 VL 538 IS 1 BP L87 EP L90 DI 10.1086/312796 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 343ML UT WOS:000088706100020 ER PT J AU Blair, WP Sankrit, R Shelton, R Sembach, KR Moos, HW Raymond, JC York, DG Feldman, PD Chayer, P Murphy, EM Sahnow, DJ Wilkinson, E AF Blair, WP Sankrit, R Shelton, R Sembach, KR Moos, HW Raymond, JC York, DG Feldman, PD Chayer, P Murphy, EM Sahnow, DJ Wilkinson, E TI Far Ultraviolet Spectroscopic Explorer observations of the supernova remnant N49 in the Large Magellanic Cloud SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (N49); Magellanic Clouds; shock waves; supernova remnants; ultraviolet : ISM ID CYGNUS LOOP; TELESCOPE AB We report a Far Ultraviolet Spectroscopic Explorer satellite observation of the supernova remnant N49 in the Large Magellanic Cloud, covering the 905-1187 Angstrom spectral region. A 30 " square aperture was used, resulting in a velocity resolution of similar to 100 km s(-1). The purpose of the observation was to examine several bright emission lines expected from earlier work and to demonstrate diffuse source sensitivity by searching for faint lines never seen previously in extragalactic supernova remnant UV spectra. Both goals were accomplished. Strong emission lines of O VI lambda lambda 1031.9, 1037.6 and C III lambda 977.0 were seen, Doppler broadened to +/-225 km s(-1) and with centroids redshifted to 350 km s(-1), consistent with the LMC. Superposed on the emission lines are absorptions by C III and O VI lambda 1031.9 at +260 km s(-1), which are attributed to warm and hot gas (respectively) in the LMC. The O VI lambda 1037.6 line is more severely affected by overlying interstellar and Hz absorption from both the LMC and our Galaxy. N III lambda 989.8 is not seen, but models indicate that overlying absorption severely attenuates this line. A number of faint lines from hot gas have also been detected, many of which have never been seen in an extragalactic supernova remnant spectrum. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80302 USA. RP Blair, WP (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA. NR 19 TC 14 Z9 14 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 2000 VL 538 IS 1 BP L61 EP L64 DI 10.1086/312793 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 343ML UT WOS:000088706100014 ER PT J AU Jenkins, EB Oegerle, WR Gry, C Vallerga, J Sembach, KR Shelton, RL Ferlet, R Vidal-Madjar, A York, DG Linsky, JL Roth, KC Dupree, AK Edelstein, J AF Jenkins, EB Oegerle, WR Gry, C Vallerga, J Sembach, KR Shelton, RL Ferlet, R Vidal-Madjar, A York, DG Linsky, JL Roth, KC Dupree, AK Edelstein, J TI The ionization of the local interstellar medium as revealed by Far Ultraviolet Spectroscopic Explorer observations of N, O, and Ar toward white dwarf stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; ISM : clouds; ultraviolet : ISM; white dwarfs ID SEQUENCE-B-STARS; CHEMICAL EVOLUTION; ELEMENT ABUNDANCES; SOLAR NEIGHBORHOOD; ORION ASSOCIATION; STELLAR SPECTRA; CHARGE-TRANSFER; OXYGEN; GAS; HELIOSPHERE AB Far Ultraviolet Spectroscopic Explorer spectra of the white dwarf stars G191-B2B, GD 394, WD 2211-495, and WD 2331-475 cover the absorption features out of the ground electronic states of N I, N II, N III, O I, and Ar I in the far-ultraviolet, providing new insights on the origin of the partial ionization of the local interstellar medium (LISM) and, for the case of G191-B2B, the interstellar cloud that immediately surrounds the solar system. Toward these targets the interstellar abundances of Ar I, and sometimes N I, are significantly below their cosmic abundances relative to H I. In the diffuse interstellar medium, these elements are not likely to be depleted onto dust grains. Generally, we expect that Ar should be more strongly ionized than H (and also O and N, whose ionizations are coupled to that of H via charge-exchange reactions) because the cross section for the photoionization of Ar I is very high. Our finding that Ar I/H I is low may help to explain the surprisingly high ionization of He in the LISM found by other investigators. Our result favors the interpretation that the ionization of the local medium is maintained by a strong extreme-ultraviolet flux from nearby stars and hot gases, rather than an incomplete recovery from a past, more highly ionized condition. C1 Princeton Univ Observ, Princeton, NJ 08544 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. ISO Data Ctr, ESA Astrophys Div, Madrid 28080, Spain. Astron Spatiale Lab, F-13376 Marseille 12, France. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Inst Astrophys, F-7504 Paris, France. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. RP Jenkins, EB (reprint author), Princeton Univ Observ, Peyton Hall, Princeton, NJ 08544 USA. RI Oegerle, William/C-9070-2012; Jenkins, Edward/P-5684-2014 OI Jenkins, Edward/0000-0003-1892-4423 NR 36 TC 90 Z9 90 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 20 PY 2000 VL 538 IS 1 BP L81 EP L85 DI 10.1086/312786 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 343ML UT WOS:000088706100019 ER PT J AU Eberhard, WG AF Eberhard, WG TI Spider manipulation by a wasp larva SO NATURE LA English DT Article ID NEPHILA-CLAVIPES ARANEAE; TETRAGNATHIDAE; PHYLOGENY C1 Univ Costa Rica, Smithsonian Trop Res Inst, San Jose, Costa Rica. Univ Costa Rica, Escuela Biol, San Jose, Costa Rica. RP Eberhard, WG (reprint author), Univ Costa Rica, Smithsonian Trop Res Inst, Ciudad Univ, San Jose, Costa Rica. NR 15 TC 80 Z9 86 U1 4 U2 54 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD JUL 20 PY 2000 VL 406 IS 6793 BP 255 EP 256 DI 10.1038/35018636 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 335PM UT WOS:000088251900035 PM 10917517 ER PT J AU Wilf, P Labandeira, CC Kress, WJ Staines, CL Windsor, DM Allen, AL Johnson, KR AF Wilf, P Labandeira, CC Kress, WJ Staines, CL Windsor, DM Allen, AL Johnson, KR TI Timing the radiations of leaf beetles: Hispines on gingers from latest Cretaceous to recent SO SCIENCE LA English DT Article ID ANGIOSPERM RADIATION; NORTH-AMERICA; EVOLUTION; CHRYSOMELIDAE; COLEOPTERA; HELICONIA; DIVERSITY; GENUS; ASSOCIATIONS; COMMUNITIES AB Stereotyped feeding damage attributable solely to rolled-leaf hispine beetles is documented on latest Cretaceous and early Eocene ginger leaves from North Dakota and Wyoming. Hispine beetles (6000 extant species) therefore evolved at least 20 million years earlier than suggested by insect body fossils, and their specialized associations with gingers and ginger relatives are ancient and phylogenetically conservative. The latest Cretaceous presence of these relatively derived members of the hyperdiverse leaf-beetle clade (Chrysomelidae, more than 38,000 species) implies that many of the adaptive radiations that account for the present diversity of leaf beetles occurred during the Late Cretaceous, contemporaneously with the ongoing rapid evolution of their angiosperm hosts. C1 Univ Michigan, Museum Paleontol, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Geol Sci, Ann Arbor, MI 48109 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Entomol, Washington, DC 20560 USA. Univ Maryland, Dept Entomol, College Pk, MD 20742 USA. Smithsonian Trop Res Inst, Balboa, Panama. Denver Museum Nat Hist, Dept Earth & Space Sci, Denver, CO 80205 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Paleobiol, Washington, DC 20560 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Bot, Washington, DC 20560 USA. RP Wilf, P (reprint author), Univ Michigan, Museum Paleontol, Ann Arbor, MI 48109 USA. EM pwilf@umich.edu NR 70 TC 94 Z9 102 U1 2 U2 13 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JUL 14 PY 2000 VL 289 IS 5477 BP 291 EP 294 DI 10.1126/science.289.5477.291 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 334DB UT WOS:000088169400039 PM 10894775 ER PT J AU Anantharamaiah, KR Viallefond, F Mohan, NR Goss, WM Zhao, JH AF Anantharamaiah, KR Viallefond, F Mohan, NR Goss, WM Zhao, JH TI Starburst in the ultraluminous galaxy Arp 220: Constraints from observations of radio recombination lines and continuum SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (Arp 220); galaxies : nuclei; galaxies : starburst; radio continuum : galaxies; radio lines : galaxies ID LUMINOUS INFRARED GALAXIES; H-II REGIONS; STAR FORMATION; MOLECULAR CLOUDS; IRAS GALAXIES; ARP-220; SPECTROSCOPY; NGC-3628; DENSITY; IC-694 AB We present observations of radio recombination lines (RRL) from the starburst galaxy Arp 220 at 8.1 GHz (H92 alpha) and 1.4 GHz (H167 alpha and H165 alpha) and at 84 GHz (H42 alpha), 96 GHz (H40 alpha) and 207 GHz (H31 alpha) using the Very Large Array and the IRAM 30 m telescope, respectively. RRLs were detected at all the frequencies except 1.4 GHz, where a sensitive upper limit was obtained. We also present continuum flux measurements at these frequencies as well as at 327 MHz made with the VLA. The continuum spectrum, which has a spectral index alpha similar to -0.6 (S-nu proportional to nu(alpha)) between 5 and 10 GHz, shows a break near 1.5 GHz, a prominent turnover below 500 MHz, and a flatter spectral index above 50 GHz. We show that a model with three components of ionized gas with different densities and area covering factors can consistently explain both RRL and continuum data. The total mass of ionized gas in the three components is 3.2 x 10(7) M., requiring 3 x 10(5) O5 stars with a total Lyman continuum production rate N-Lyc similar to 1.3 x 10(55) photons s(-1). The ratio of the expected to observed Br alpha and Br gamma fluxes implies a dust extinction A(V) similar to 45 mag. The derived Lyman continuum photon production rate implies a continuous star formation rate (SFR) averaged over the lifetime of OB stars of similar to 240 M yr(-1). The Lyman continuum photon Production rate of similar to 3% associated with the high-density H II regions implies a similar SFR at recent epochs (t < 10(5) yr). An alternative model of high-density gas, which cannot be excluded on the basis of the available data, predicts 10 times higher SFR at recent epochs. If confirmed, this model implies that star formation in Arp 220 consists of multiple starbursts of very high SFR (few times 10(3) M. yr(-1)) and short duration (similar to 10(5) yr). The similarity of IR excess, L-IR/L-Ly alpha similar to 24, in Arp 220 to values observed in starburst galaxies shows that most of the high luminosity of Arp 220 is due to the ongoing starburst rather than to a hidden active galactic nucleus (AGN). A comparison of the IR excesses in Arp 220, the Galaxy, and M33 indicates that the starburst in Arp 220 has an initial mass function that is similar to that in normal galaxies and has a duration longer than 107 yr. If there was no infall of gas during this period, then the star formation efficiency (SFE) in Arp 220 is similar to 50%. The high SFR and SFE in Arp 220 is consistent with their known dependences on mass and density of gas in star-forming regions of normal galaxies. C1 Natl Radio Astron Observ, Socorro, NM 87801 USA. Raman Res Inst, Bangalore 560080, Karnataka, India. Observ Paris, Dept Matiere Interstellaire & Radioastron Millime, F-75014 Paris, France. Indian Inst Sci, Joint Astron Program, Bangalore 560012, Karnataka, India. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Anantharamaiah, KR (reprint author), Natl Radio Astron Observ, Socorro, NM 87801 USA. RI Anantharamaiah , K. R./E-5369-2012; M, Manjunath/N-4000-2014 OI M, Manjunath/0000-0001-8710-0730 NR 44 TC 74 Z9 74 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 10 PY 2000 VL 537 IS 2 BP 613 EP 630 DI 10.1086/309063 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 338YP UT WOS:000088451100008 ER PT J AU Blair, WP Morse, JA Raymond, JC Kirshner, RP Hughes, JP Dopita, MA Sutherland, RS Long, KS Winkler, PF AF Blair, WP Morse, JA Raymond, JC Kirshner, RP Hughes, JP Dopita, MA Sutherland, RS Long, KS Winkler, PF TI Hubble Space Telescope observations of oxygen-rich supernova remnants in the Magellanic Clouds. II. Elemental abundances in N132D and 1E 0102.2-7219 SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (1E 0102.2-7219, N132D); Magellanic Clouds; shock waves; supernova remnants ID CASSIOPEIA-A SUPERNOVA; RADIATIVE SHOCK-WAVES; X-RAY SPECTROSCOPY; NOVA REMNANT; OPTICAL-EMISSION; INTERSTELLAR EXTINCTION; MASS-LOSS; YOUNG; MODELS; DISTANCE AB We present Hubble Space Telescope (HST) Wide Field and Planetary Camera 2 images and Faint Object Spectrograph data of two young supernova remnants in the Magellanic Clouds, N132D (LMC) and 1E 0102.2-7219 (SMC). The spectra cover essentially the entire UV/optical range available to HST and provide the first true comparison of UV/optical line intensities from astrophysical shocks that do not depend on scalings from different aperture sizes or instruments. For the spectra, we isolated specific knots and filaments that contain fast-moving debris of nuclear-processed material that are devoid of hydrogen and appear to have originated from the cores of the progenitor stars. In N132D we also observed a knot on the outer rim of the remnant that represents a shocked interstellar cloud. In the debris from both remnants, we identify only the elements O, Ne, C, and Mg. We find no evidence for oxygen-burning products, such as S, Ca, Ar, etc., which are seen in Cas A and are expected from models of Type II supernovae. We suggest that the progenitor stars of N132D and 1E 0102.2-7219 had large, oxygen-rich mantles (perhaps Wolf-Rayet stars) and may be the products of Type Ib supernovae. Shock modeling demonstrates systematic differences in the relative abundances in the O-rich debris, possibly pointing to different progenitor masses for these two objects. The shocked interstellar knot in N132D shows that we are probably seeing a range of conditions within the similar to 1 " aperture and that no evidence is present for enrichment by a precursor star wind. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Colorado, Ctr Astrophys & Space Astron, Dept Astrophys & Planetary Sci, Boulder, CO 80309 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08854 USA. Australian Natl Univ, Mt Stromlo & Siding Spring Observ, Weston, ACT 2611, Australia. CEA Saclay, Lorme Merisiers, Serv Astrophys, F-91191 Gif Sur Yvette, France. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Middlebury Coll, Dept Phys, Middlebury, VT 05753 USA. RP Blair, WP (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA. EM wpb@pha.jhu.edu; morsey@casa.colorado.edu; raymond@cfa.harvard.edu; kirshner@cfa.harvard.edu; jph@physics.rutgers.edu; mad@mso.anu.edu.au; Ralph.Sutherland@anu.edu.au; long@stsci.edu; winkler@panther.middlebury.edu RI Dopita, Michael/P-5413-2014 OI Dopita, Michael/0000-0003-0922-4986 NR 73 TC 79 Z9 79 U1 1 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 10 PY 2000 VL 537 IS 2 BP 667 EP 689 DI 10.1086/309077 PN 1 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 338YP UT WOS:000088451100013 ER PT J AU Williams, JP Myers, PC AF Williams, JP Myers, PC TI Evidence for pressure-driven flows and turbulent dissipation in the serpens NW cluster SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (Serpens); ISM : kinematics and dynamics; stars : formation; turbulence ID MOLECULAR CLOUD CORES; YOUNG STELLAR OBJECTS; STAR-FORMATION; PROTOSTARS; EVOLUTION; CONTINUUM; PROFILES; COLLAPSE; MOTIONS; N2H+ AB We have mapped the dense gas distribution and dynamics in the northwest region of the Serpens molecular cloud in the CS (2-1) and N2H+ (1-0) lines and 3 mm continuum using the FCRAO telescope and the Berkeley-Illinois-Maryland Association (BIMA) interferometer. Seven continuum sources are found. The N2H+ spectra are optically thin, and fits to the seven hyperfine components are used to determine the distribution of velocity dispersion. Eight cores, two with continuum sources, six without, lie at a local line width minimum and optical depth maximum. The CS spectra are optically thick and generally self-absorbed over the full 0.2 pc extent of the map. We use the line wings to trace outflows around at least three, and possibly four, of the continuum sources and the asymmetry in the self-absorption as a diagnostic of relative motions between core centers and envelopes. The quiescent regions with low N2H+ line width tend to have more asymmetric CS spectra than the spectra around the continuum sources, indicating higher infall speeds. These regions have typical sizes similar to 5000 AU, line widths similar to 0.5 km s(-1), and infall speeds similar to 0.05 km s(-1). The correlation of CS asymmetry with N2H+ velocity dispersion suggests that the inward flows of material that build up pre-protostellar cores are driven at least partly by a pressure gradient rather than by gravity alone. We discuss a scenario for core formation and eventual star-forming collapse through the dissipation of turbulence. C1 Natl Radio Astron Observ, Tucson, AZ 85721 USA. Univ Florida, Dept Astron, Gainesville, FL 32611 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Williams, JP (reprint author), Natl Radio Astron Observ, 949 N Cherry Ave, Tucson, AZ 85721 USA. RI Williams, Jonathan/B-1643-2009; OI Williams, Jonathan/0000-0001-5058-695X NR 34 TC 39 Z9 39 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 10 PY 2000 VL 537 IS 2 BP 891 EP 903 DI 10.1086/309084 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 338YP UT WOS:000088451100029 ER PT J AU Pierpaoli, E Scott, D White, M AF Pierpaoli, E Scott, D White, M TI Still flat after all these years! SO MODERN PHYSICS LETTERS A LA English DT Article ID ANISOTROPY; RADIATION AB The Universe could be spatially fiat, positively curved or negatively curved. Each option has been popular at various times, partly affected by an understanding that models tend to evolve away from flatness. The curvature of the Universe is amenable to measurement, through tests such as the determination of the angles of sufficiently large triangles. The angle subtended by the characteristic scale on the cosmic microwave sky provides a direct test, which has now been realized through a combination of exquisite results from a number of CMB experiments. After a long and detailed investigation, with many false clues, it now seems that the mystery of the curvature of the Universe is now solved. It is an open and shut case: the Universe is flat!. C1 Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Canadian Inst Theoret Astrophys, Toronto, ON M5S 3H8, Canada. RP Pierpaoli, E (reprint author), Univ British Columbia, Dept Phys & Astron, 6224 Agr Rd, Vancouver, BC V6T 1Z1, Canada. RI White, Martin/I-3880-2015; OI White, Martin/0000-0001-9912-5070; Pierpaoli, Elena/0000-0002-7957-8993 NR 14 TC 6 Z9 6 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-7323 J9 MOD PHYS LETT A JI Mod. Phys. Lett. A PD JUL 10 PY 2000 VL 15 IS 21 BP 1357 EP 1362 DI 10.1142/S0217732300001821 PG 6 WC Physics, Nuclear; Physics, Particles & Fields; Physics, Mathematical SC Physics GA 359VA UT WOS:000089631700002 ER PT J AU Balakrishnan, N Dalgarno, A Forrey, RC AF Balakrishnan, N Dalgarno, A Forrey, RC TI Vibrational relaxation of CO by collisions with He-4 at ultracold temperatures SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INTERACTION ENERGY SURFACE; ATOM-MOLECULE COLLISIONS; INELASTIC-COLLISIONS; COORDINATE DEPENDENCE; INFRARED-SPECTRUM; GAS-PHASE; SCATTERING; DEACTIVATION; PHOTOASSOCIATION; COMPLEX AB Quantum mechanical coupled channel scattering calculations are performed for the ro-vibrational relaxation of CO in collisions with ultracold He atoms. The van der Waals well in the interaction potential supports a number of shape resonances which significantly influence the relaxation cross sections at energies less than the well depth. Feshbach resonances are also found to occur near channel thresholds corresponding to the j = 1 rotational level in the v = 0 and v = 1 vibrational levels. Their existence influences dramatically the limiting values of the elastic scattering cross sections and the rotational quenching rate coefficients from the j = 1 level. We present complex scattering lengths for several low lying rotational levels of CO which characterize both elastic and inelastic collisions in the limit of zero temperature. Our results for the vibrational relaxation of CO (v = 1) are in good agreement with available experimental and theoretical results. (C) 2000 American Institute of Physics. [S0021-9606(00)01526-9]. C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. Penn State Univ, Berks Lehigh Valley Coll, Reading, PA 19610 USA. RP Balakrishnan, N (reprint author), Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, 60 Garden St, Cambridge, MA 02138 USA. NR 35 TC 93 Z9 94 U1 3 U2 11 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUL 8 PY 2000 VL 113 IS 2 BP 621 EP 627 AR PII [S0021-9606(00)01526-9] DI 10.1063/1.481838 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 329DB UT WOS:000087889900021 ER PT J AU Werren, JH Windsor, DM AF Werren, JH Windsor, DM TI Wolbachia infection frequencies in insects: evidence of a global equilibrium? SO PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES LA English DT Article DE Wolbachia; infection frequency; arthropods ID CYTOPLASMIC INCOMPATIBILITY; MOLECULAR-IDENTIFICATION; REPRODUCTIVE ISOLATION; PHYLOGENETIC ANALYSIS; DROSOPHILA; ARTHROPODS; EVOLUTION AB Wolbachia are a group of cytoplasmically inherited bacteria that cause reproduction alterations in arthropods, including parthenogenesis, reproductive incompatibility, feminization of genetic males and male killing. Previous general surveys of insects in Panama and Britain found Wolbachia to be common, occurring in 16-22% of species. Here, using similar polymerase chain reaction methods, we report that 19.3% of a sample of temperate North American insects are infected with Wolbachia, we frequency strikingly similar to frequencies found in two other studies in widely separated locales. The results may indicate a widespread equilibrium of Wolbachia infection frequencies in insects whose maintenance remains to be explained. Alternatively, Wolbachia may be increasing in global insect communities. Within each of the three geographic regions surveyed, Hymenoptera are more frequently infected with A group Wolbachia and Lepidoptera more frequently infected with B group Wolbachia. C1 Univ Rochester, Dept Biol, Rochester, NY 14627 USA. Smithsonian Trop Res Inst, Balboa, Panama. RP Werren, JH (reprint author), Univ Rochester, Dept Biol, Rochester, NY 14627 USA. EM werr@mail.rochester.edu NR 33 TC 391 Z9 434 U1 4 U2 48 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 0962-8452 J9 P ROY SOC B-BIOL SCI JI Proc. R. Soc. B-Biol. Sci. PD JUL 7 PY 2000 VL 267 IS 1450 BP 1277 EP 1285 DI 10.1098/rspb.2000.1139 PG 9 WC Biology; Ecology; Evolutionary Biology SC Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Evolutionary Biology GA 335BM UT WOS:000088222200003 PM 10972121 ER PT J AU Anglin, J AF Anglin, J TI Theoretical physics - Why trapped atoms are attractive SO NATURE LA English DT Editorial Material ID VORTICES C1 Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. RP Anglin, J (reprint author), Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, 60 Garden St,MS 14, Cambridge, MA 02138 USA. NR 11 TC 12 Z9 12 U1 0 U2 2 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD JUL 6 PY 2000 VL 406 IS 6791 BP 29 EP 30 DI 10.1038/35017678 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 330ZE UT WOS:000087991200027 ER PT J AU Ben-Itzhak, I Wells, E Carnes, KD Krishnamurthi, V Weaver, OL Esry, BD AF Ben-Itzhak, I Wells, E Carnes, KD Krishnamurthi, V Weaver, OL Esry, BD TI Symmetry breakdown in ground state dissociation of HD SO PHYSICAL REVIEW LETTERS LA English DT Article ID EARLY UNIVERSE; ION; SPECTROSCOPY; IONIZATION; CHEMISTRY AB Experimental studies of the dissociation of the electronic ground state of HD+ following ionization of HD by fast proton impact indicate that the H+ + D(1s) dissociation channel is more likely than the H(1s) + D+ dissociation channel by about 7%. This isotopic symmetry breakdown is due to the finite nuclear mass correction to the Born-Oppenheimer approximation which makes the 1s sigma state 3.7 meV lower than the 2p sigma state at the dissociation limit. The measured fractions of the two dissociation channels are in agreement with coupled-channels calculations of 1s sigma to 2p sigma transitions. C1 Kansas State Univ, Dept Phys, JR Macdonald Lab, Manhattan, KS 66506 USA. Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Mol Phys, Cambridge, MA 02138 USA. RP Ben-Itzhak, I (reprint author), Kansas State Univ, Dept Phys, JR Macdonald Lab, Manhattan, KS 66506 USA. RI Ben-Itzhak, Itzik/J-8273-2012; Esry, Brett/H-7511-2013; Weaver, Larry/I-5201-2013; OI Ben-Itzhak, Itzik/0000-0002-6214-3520; Esry, Brett/0000-0003-3207-8526; Weaver, Larry/0000-0003-3083-2724; Wells, Eric/0000-0002-1044-4479 NR 13 TC 27 Z9 28 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUL 3 PY 2000 VL 85 IS 1 BP 58 EP 61 DI 10.1103/PhysRevLett.85.58 PG 4 WC Physics, Multidisciplinary SC Physics GA 330JR UT WOS:000087959400015 ER PT J AU Remo, JL AF Remo, JL TI Energy requirements and payload masses for near-earth objects hazard mitigation SO ACTA ASTRONAUTICA LA English DT Article ID MISSIONS AB The effectiveness of various high energy density sources and their coupling coefficients are evaluated in terms of the required payload mass necessary to change the orbit of a Earth-threatening near-Earth object (NEO) by 6 m/s. Included in the analysis are high explosive, high speed projectiles, nuclear explosives and their radiational high intensity lasers and concentrated solar energy. It is shown that a given velocity change will be equal to the product of the payload energy and the coupling coefficient divided by the mass of the NEO which superficially portrays a linear relationship. Factors upon which the coupling coefficient depends are discussed. An overall review of the sequential process to mitigate a potentially hazardous NEO is presented. (C) 2000 Published by Elsevier Science Ltd. C1 Harvard Smithsonian Ctr Astrophys, Planetary Sci Div, Cambridge, MA 02138 USA. RP Remo, JL (reprint author), Harvard Smithsonian Ctr Astrophys, Planetary Sci Div, 60 Garden St,Mail Stop 18, Cambridge, MA 02138 USA. NR 28 TC 12 Z9 12 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD JUL PY 2000 VL 47 IS 1 BP 35 EP 50 DI 10.1016/S0094-5765(00)00008-4 PG 16 WC Engineering, Aerospace SC Engineering GA 341KN UT WOS:000088589700005 ER PT J AU Lellinger, DB AF Lellinger, DB TI On the lectotypification of Danaea elliptica SO AMERICAN FERN JOURNAL LA English DT Article AB Prior lectotypifications of Danaea elliptica are rejected because they did not take into account the one adequate specimen cited by the author of the species. This specimen is chosen here as lectotype, which enables the name D. elliptica to continue to be used in its usual sense. C1 US Natl Herbarium, Smithsonian Inst, Washington, DC 20560 USA. RP Lellinger, DB (reprint author), US Natl Herbarium, Smithsonian Inst, Washington, DC 20560 USA. NR 9 TC 1 Z9 2 U1 0 U2 0 PU AMER FERN SOC INC PI WASHINGTON PA C/O DAVID B LELLINGER, SMITHSONIAN INST, BOTANY DEPT, WASHINGTON, DC 20560 USA SN 0002-8444 J9 AM FERN J JI Am. Fern J. PD JUL-SEP PY 2000 VL 90 IS 3 BP 100 EP 103 DI 10.2307/1547325 PG 4 WC Plant Sciences SC Plant Sciences GA 402XG UT WOS:000167013000002 ER PT J AU Sallum, MAM Schultz, TR Wilkerson, RC AF Sallum, MAM Schultz, TR Wilkerson, RC TI Phylogeny of Anophelinae (Diptera Culicidae) based on morphological characters SO ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA LA English DT Article DE Anopheles; Culicidae; phylogeny; morphology ID AMPLIFIED POLYMORPHIC DNA; CLADISTIC-ANALYSIS; MOSQUITOS DIPTERA; SUBGENUS CELLIA; GENUS ANOPHELES; SOUTH-AMERICA; CLASSIFICATION; SYSTEMATICS; SERIES AB Phylogenetic relationships of mosquitoes in the subfamily Anophelinae are presented based on a cladistic analysis of 163 morphological characters from females, males, fourth-instar larvae, and pupae of 64 species. Species examined include one Chagasia Cruz, three Bironella Theobald, and 60 species representing all six subgenera of Anopheles Meigen. Uranotaenia lowii Theobald and Aedeomyia squamipennis (Lynch Arribalzaga) are used as outgroups. This analysis indicates that Anophelinae is monophyletic, that Chagasia is the earliest-diverged lineage within Anophelinae, and that the genus Anopheles, as currently defined, is paraphyletic because it excludes Bironella. Four nonhomoplastic synapomorphies support the monophyly of the clade composed of the genera Bironella and Anopheles. Three major lineages are recognized within this clade. The basal lineage (lineage 1) contains An. (Nyssorhynchus), An. (Kerteszia), and An. implexus (Theobald). This analysis supports the monophyly of the sister groups Nyssorhynchus Blanchard and Kerteszia Theobald, but finds the Albimanus, Argyritarsis, and Myzorhynchella sections of the subgenus Nyssorhynchus to be paraphyletic. The second lineage (lineage 2) contains species of the subgenus Cellia Theobald, which is monophyletic. Except for the Cellia series, however, all other series of the subgenus Cellia are paraphyletic. The third lineage (lineage 3) contains species of the subgenera Anopheles Meigen, Stethomyia Theobald, Lophopodomyia Antunes, and of the genus Bironella. Bironella and Stethomyia are monophyletic sister groups. The Lophoscelomyia and Arribalzagia series are monophyletic. The Arribalzagia and Cycloleppteron series are sister groups nested within the Myzorhynchus series. We conclude that there is no support for the generic recognition of Bironella, nor the subgeneric rank of Lophopodomyia and Stethomyia. C1 Univ Sao Paulo, Fac Saude Publ, Dept Epidemiol, BR-01246904 Sao Paulo, Brazil. Smithsonian Inst, Natl Museum Amer Hist, Dept Entomol, Washington, DC 20560 USA. Smithsonian Inst, Walter Reed Army Inst Res, Museum Support Ctr, Dept Entomol, Washington, DC 20560 USA. RP Sallum, MAM (reprint author), Univ Sao Paulo, Fac Saude Publ, Dept Epidemiol, Av Dr Arnaldo 715, BR-01246904 Sao Paulo, Brazil. RI Sallum, Maria/B-8537-2012 NR 47 TC 64 Z9 69 U1 1 U2 7 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 0013-8746 EI 1938-2901 J9 ANN ENTOMOL SOC AM JI Ann. Entomol. Soc. Am. PD JUL PY 2000 VL 93 IS 4 BP 745 EP 775 DI 10.1603/0013-8746(2000)093[0745:POADCB]2.0.CO;2 PG 31 WC Entomology SC Entomology GA 359VE UT WOS:000089632100006 ER PT J AU Eberhard, WG AF Eberhard, WG TI Behavior and reproductive status of Microsepsis armillata (Diptera : Sepsidae) flies away from oviposition sites SO ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA LA English DT Article DE Microsepsis armillata; mating; aggregations; virgin females; Sepsidae ID SPERM STORAGE; CYNIPSEA; SIZE AB The mystery of where virgin female Microsepsis armillata (Melander & Spuler) copulate has been solved with the discovery of sexual activity in small aggregations that are not tightly associated with the oviposition sites, where matings have been observed previously in this and other sepsid species. Nonvirgin females also mate in these aggregations, and matings at such sites may help explain the otherwise puzzling variations in male precopulatory riding behavior in other sepsids. Approximately 25% of the unpaired females in aggregations carl-led an unlaid egg in her bursa, and larvae had hatched from some of these eggs. Retention of a bursal egg could prevent intromission by males. C1 Smithsonian Trop Res Inst, San Jose, Costa Rica. Univ Costa Rica, Escuela Biol, San Jose, Costa Rica. RP Eberhard, WG (reprint author), Smithsonian Trop Res Inst, Ciudad Univ, San Jose, Costa Rica. NR 22 TC 7 Z9 8 U1 0 U2 3 PU ENTOMOL SOC AMER PI LANHAM PA 9301 ANNAPOLIS RD, LANHAM, MD 20706 USA SN 0013-8746 J9 ANN ENTOMOL SOC AM JI Ann. Entomol. Soc. Am. PD JUL PY 2000 VL 93 IS 4 BP 966 EP 971 DI 10.1603/0013-8746(2000)093[0966:BARSOM]2.0.CO;2 PG 6 WC Entomology SC Entomology GA 359VE UT WOS:000089632100031 ER PT J AU Jarrett, TH Chester, T Cutri, R Schneider, S Rosenberg, J Huchra, JP Mader, J AF Jarrett, TH Chester, T Cutri, R Schneider, S Rosenberg, J Huchra, JP Mader, J TI 2MASS extended sources in the zone of avoidance SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : general; HII regions; infrared radiation; ISM : individual (W51); surveys ID LARGE-SCALE STRUCTURES; REDSHIFT-SURVEY; MILKY-WAY; VELOCITY-FIELD; IRAS GALAXIES; H-I; UNIVERSE; COMPLEX; LINE AB A new high-resolution near-infrared mapping effort, the Two Micron All Sky Survey (2MASS), is now underway and will provide a complete census of galaxies as faint as 13.5 mag (3 mJy) at 2.2 mu m for most of the sky, and similar to 12.1 mag (10 mJy) for regions veiled by the Milky Way. This census has already discovered nearby galaxies previously hidden behind our Galaxy and will allow delineation of large-scale structures in the distribution of galaxies across the whole sky. Here we report the detection and discovery of new extended sources from this survey for fields incorporating the Galactic plane at longitudes between 40 degrees and 70 degrees. Follow-up H I 21 cm and optical spectroscopy observations provide positive confirmation for 14 of the new 2MASS galaxies. We perform an internal completeness and reliability analysis for the sample, consisting of 7000 sources in similar to 1000 deg(2) of area, including galaxies and Galactic nebulae from the W51 giant molecular cloud. The area-normalized detection rate is about one to two galaxies per deg2 brighter than 12.1 mag (10 mJy), roughly constant with Galactic latitude throughout the "Zone of Avoidance," of which 85%-95% are newly discovered sources. In conjunction with the deep H I surveys, 2MASS will greatly increase the current census of galaxies hidden behind the Milky Way. Moreover, owing to its sensitivity to elliptical and other gas-poor galaxies, 2MASS will provide a key complementary data set to that of the gas-rich-sensitive H I surveys of the Milky Way galaxy, potentially uncovering nearby galaxies critical to the local gravity and mass density fields. C1 CALTECH, Ctr Infrared Proc & Anal, Jet Prop Lab, Pasadena, CA 91125 USA. Univ Massachusetts, Astron Program, Amherst, MA 01003 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Jarrett, TH (reprint author), CALTECH, Ctr Infrared Proc & Anal, Jet Prop Lab, MS 100-22, Pasadena, CA 91125 USA. EM jarrett@ipac.caltech.edu; tchester@ipac.caltech.edu; roc@ipac.caltech.edu; schneider@phast.umass.edu; jessica@phast.umass.edu; huchra@cfa.harvard.edu; jmader@cfa.harvard.edu NR 53 TC 73 Z9 73 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUL PY 2000 VL 120 IS 1 BP 298 EP 313 DI 10.1086/301426 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 341HX UT WOS:000088585900019 ER PT J AU Evans, NR Vinko, J Wahlgren, GM AF Evans, NR Vinko, J Wahlgren, GM TI The orbit of the classical Cepheid AW Persei revisited SO ASTRONOMICAL JOURNAL LA English DT Article DE Cepheids; stars : evolution; stars : fundamental parameters ID AGE MAIN-SEQUENCE; RADIAL-VELOCITIES; CORRELATION SPECTROMETER; BINARY CEPHEIDS; DISTANCE SCALE; MASS RATIOS; HIPPARCOS; CATALOG; EVOLUTION; STARS AB We have obtained new velocity data for the classical Cepheid AW Persei and used them to derive a new orbit for the binary star system of which it is part. The orbital period (40 yr) is slightly longer than the previously determined orbit. The lower limit to the mass of the secondary from the new mass function is 6.6 M.. This is much larger than the mass inferred from the spectral type of the companion, 4.0 M.. This implies that the secondary is itself a binary in a short-period orbit. We have used an IUE high-resolution spectrum to confirm the spectral contributions from the Cepheid and the hottest companion at 2600 Angstrom. C1 Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. Jate Univ, Dept Opt, H-6720 Szeged, Hungary. Univ Lund, Dept Phys, S-22362 Lund, Sweden. RP Evans, NR (reprint author), Smithsonian Astrophys Observ, 60 Garden St, Cambridge, MA 02138 USA. OI Vinko, Jozsef/0000-0001-8764-7832 NR 25 TC 6 Z9 6 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUL PY 2000 VL 120 IS 1 BP 407 EP 412 DI 10.1086/301444 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 341HX UT WOS:000088585900027 ER PT J AU Greene, TP Lada, CJ AF Greene, TP Lada, CJ TI High-resolution near-infrared spectra of protostars SO ASTRONOMICAL JOURNAL LA English DT Article DE infrared radiation; stars : atmospheres; stars : formation; stars : rotation; techniques : spectroscopic ID YOUNG STELLAR OBJECTS; RHO-OPHIUCHI CLOUD; MAIN-SEQUENCE STARS; SPECTROSCOPY AB We present new high-resolution (R similar or equal to 21,000) near-infrared (lambda = 2 mu m) spectroscopic observations of a sample of Class I and flat-spectrum protostellar objects in the rho Ophiuchi dark cloud. None of the five Class I spectra show CO upsilon = 0-2 absorption features, consistent with high K-band continuum veilings, 4 less than or similar to r(k) less than or similar to 20, and fast stellar rotation, assuming that the underlying protostellar photospheres are of late spectral type, as is suggested by the low luminosities of most of these objects. Two of the flat-spectrum protostellar objects also show no absorption features and are likely to be highly veiled. The remaining two flat-spectrum sources show weak, broad absorptions, which are consistent with an origin in quickly rotating (upsilon sin i approximate to 50 km s(-1)) late-type stellar photospheres, which are also strongly veiled (r(k) similar or equal to 3-4). These observations provide further evidence that: (1) Class I sources are highly veiled at near-infrared wavelengths, confirming previous findings of lower resolution spectroscopic studies, and (2) flat-spectrum protostars rotate more rapidly than classical T Tauri stars (Class II sources), supporting findings from a recent high-resolution spectroscopic study of other flat-spectrum sources in this cloud. In addition our observations are consistent with the high rotation rates derived for two of the Class I protostellar objects in our sample from observations of variable hard X-ray emission obtained with the ASCA satellite. These observations suggest that certain Class I sources can rotate even more rapidly than flat-spectrum protostars, near breakup velocity. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. RP Greene, TP (reprint author), NASA, Ames Res Ctr, MS 245-6, Moffett Field, CA 94035 USA. EM tgreene@mail.arc.nasa.gov; clada@cfa.harvard.edu NR 24 TC 24 Z9 24 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUL PY 2000 VL 120 IS 1 BP 430 EP 436 DI 10.1086/301452 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 341HX UT WOS:000088585900029 ER PT J AU Linden-Vornle, MJD Norgaard-Nielsen, HU Jorgensen, HE Hansen, L Haas, M Klaas, U Abraham, P Lemke, D Rasmussen, IL Schnopper, HW AF Linden-Vornle, MJD Norgaard-Nielsen, HU Jorgensen, HE Hansen, L Haas, M Klaas, U Abraham, P Lemke, D Rasmussen, IL Schnopper, HW TI Deep far infrared ISOPHOT survey in "Selected Area 57" - I. Observations and source counts SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE infrared : galaxies; galaxies : evolution; galaxies : starburst ID NORTH ECLIPTIC POLE; GALAXY EVOLUTION; IRAS SURVEY; REDSHIFT; CATALOG; SKY AB We present here the results of a deep survey in a 0.4 deg(2) blank field in Selected Area 57 conducted with the ISOPHOT instrument aboard ESAs Infrared Space Observatory (ISO1) at both 60 mu m and 90 mu m. The resulting sky maps have a spatial resolution of 15 x 23 arcsrc(2) per pixel which is much higher than the 90 x 90 arcsec(2) pixels of the IRAS All Sky Survey. We describe the main instrumental effects encountered in our data, outline our data reduction and analysis scheme and present astrometry and photometry of the detected point sources. With a formal signal to noise ratio of 6.75 we have source detection limits of 90 mJy at 60 mu m and 50 mJy at 90 mu m To these limits we find cumulated number densities of 5+/-3.5 deg(-2) at 60 mu m and 14.8+/-5.0 deg(-2) at 90 mu m. These number densities of sources are found to be lower than previously reported results from ISO but the data do not allow us to discriminate between no-evolution scenarios and various evolutionary models. C1 Astron Observ, Niels Bohr Inst Astron Phys & Geophys, DK-2100 Copenhagen O, Denmark. Danish Space Res Inst, DK-2100 Copenhagen O, Denmark. Max Planck Inst Astron, D-69117 Heidelberg, Germany. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Linden-Vornle, MJD (reprint author), Astron Observ, Niels Bohr Inst Astron Phys & Geophys, Juliane Maries Vej 30, DK-2100 Copenhagen O, Denmark. EM michael@astro.ku.dk NR 41 TC 21 Z9 21 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUL PY 2000 VL 359 IS 1 BP 51 EP 64 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 338MT UT WOS:000088424400006 ER PT J AU Benedettini, M Giannini, T Nisini, B Tommasi, E Lorenzetti, D Di Giorgio, AM Saraceno, P Smith, HA White, GJ AF Benedettini, M Giannini, T Nisini, B Tommasi, E Lorenzetti, D Di Giorgio, AM Saraceno, P Smith, HA White, GJ TI The ISO spectroscopic view of the HH 24-26 region SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : formation; stars : individual : HH24MMS, HH25MMS, HH26IR; ISM : jets and outflows; infrared : ISM : lines and bands ID HERBIG-HARO OBJECTS; SHORT-WAVELENGTH SPECTROMETER; MOLECULAR CLOUDS; LWS OBSERVATIONS; EMISSION; STARS; SHOCKS; CALIBRATION; DISCOVERY; HH-24-26 AB We report the results of an investigation, performed with the ISO spectrometers (LWS and SWS), on the star forming region associated with the Herbig-Haro objects HH 24-25 and 26. Low-resolution LWS spectra (45-197 mu m) were observed towards the HH24MMS, HH25MMS and HH26IR sources as well as the HH26IR outflow. In addition, SWS scans of the pure H(2) rotational lines towards HH24MMS were acquired. Emission from [O I] 63 mu m and [C II] 158 mu m appears widespread while molecular transitions of carbon monoxide and water vapour were detected only towards HH25MMS and the blue lobe of HH26IR. From the analysis of the observed emission we deduce that the gas towards HH24MMS and HH25MMS is excited at densities similar to 10(6) cm(-3) and temperatures ranging from 650 to 1400 K in HH24MMS and from 150 to 550 K in HH25MMS. Along the blue lobe of the HH26IR outflow, a more diffuse (n(H2) similar to 10(4) cm(-3)) and warm (T similar to 1800 K) gas is found. Both the molecular (CO, H(2)O and H(2)) and atomic ([O I]) emission in the three sources can be interpreted as due to shock excitation, and a mixture of both C- and J-type shocks are required to reproduce most of the observed characteristics of the spectra. The derived water abundances (3 10(-7) -9 10(-6)) are lower than expected in warm shock excited gas, a result which has also been found in other similar regions investigated with ISO. The total cooling derived from the gas component traced by the FIR lines is always of the same order or larger than the cooling due to the molecular hydrogen as traced by the H(2) 2.12 mu m line; although this latter could be underestimated if the dust extinction is not negligible, however it is evident that a significant fraction of the energy released in the shocks is re-radiated away by the far infrared lines. Finally, the [C II] 158 mu m line intensities are rather constant at all of the observed positions, excluding the presence of strong photo-dissociation regions related to the nearby IR sources. C1 CNR, Ist Fis Spazio Interplanetario, Area Ric Tor Vergata, I-00133 Rome, Italy. Osserv Astron Roma, I-00040 Monte Porzio Catone, Italy. Univ Roma La Sapienza, I-00161 Rome, Italy. Agenzia Spaziale Italiana, I-00161 Rome, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Queen Mary Univ London, London E1 4NS, England. Stockholm Observ, S-13336 Saltsjobaden, Sweden. RP Benedettini, M (reprint author), CNR, Ist Fis Spazio Interplanetario, Area Ric Tor Vergata, Via del Fosso del Cavaliere 100, I-00133 Rome, Italy. EM milena@ifsi.rm.cnr.it OI Giannini, Teresa/0000-0002-0224-096X; , Brunella Nisini/0000-0002-9190-0113 NR 38 TC 20 Z9 20 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUL PY 2000 VL 359 IS 1 BP 148 EP 158 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 338MT UT WOS:000088424400014 ER PT J AU Corbel, S Fender, RP Tzioumis, AK Nowak, M McIntyre, V Durouchoux, P Sood, R AF Corbel, S Fender, RP Tzioumis, AK Nowak, M McIntyre, V Durouchoux, P Sood, R TI Coupling of the X-ray and radio emission in the black hole candidate and compact jet source GX 339-4 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : individual : GX 339-4; gamma rays : observations; radio continuum : stars; X-rays : stars; accretion, accretion disks; black hole physics ID MULTIWAVELENGTH OBSERVATIONS; RELATIVISTIC JETS; HIGH STATE; OPTICAL OBSERVATIONS; TIMING EXPLORER; GRO J1655-40; HARD STATE; CYGNUS X-1; GX-339-4; GX339-4 AB We report the results of a long-term campaign of radio, soft- and hard-X-ray observations of the galactic black hole candidate GX 339-4, In the Low-Hard X-ray state the system displays a strong 3-way linear correlation between soft- and hard-X-rays and radio emission, implying a coupling between the Comptonising corona and a radio-emitting compact jet. In this state the radio emission is linearly polarised at a level of around 2%, with an almost constant polarisation angle, indicative of a favored axis in this system probably related to the compact jet and/or black hole spin axis. In the Off X-ray state the radio emission declines with the X-ray emission to below detectable levels, suggesting that it is simply a lower-luminosity version of the Low-Hard state. In the High-Soft state both the hard-X-ray and radio emission are suppressed. We also note that the transitions from the Low-Hard state to the High-Soft state (and the reverse) are possibly associated with discrete ejection(s) of expanding relativistic plasma. C1 CEA Saclay, Serv Astrophys, F-91191 Gif Sur Yvette, France. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Ctr High Energy Astrophys, NL-1098 SJ Amsterdam, Netherlands. CSIRO, Australia Telescope Natl Facil, Paul Wild Observ, Narrabri, NSW 2390, Australia. Univ Colorado, JILA, Boulder, CO 80309 USA. Univ Sydney, Sch Phys, Dept Astrophys, Sydney, NSW 2006, Australia. Australian Def Force Acad, Sch Phys, Canberra, ACT 2600, Australia. RP Corbel, S (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. EM corbel@discovery.saclay.cea.fr NR 85 TC 231 Z9 233 U1 2 U2 2 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUL PY 2000 VL 359 IS 1 BP 251 EP 268 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 338MT UT WOS:000088424400022 ER PT J AU Bocchino, F Maggio, A Sciortino, S Raymond, J AF Bocchino, F Maggio, A Sciortino, S Raymond, J TI Multi-wavelength observations and modelling of shock-cloud interaction regions in the Vela Supernova Remnant SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE shock waves; ISM : clouds; ISM : individual objects : Vela SNR; ISM : structure; ISM : supernova remnants; ultraviolet : ISM ID ROSAT-PSPC OBSERVATION; SOUTHERN SPECTROPHOTOMETRIC STANDARDS; CYGNUS-LOOP; OPTICAL-EMISSION; X-RAY; INTERSTELLAR-MEDIUM; NORTHEAST REGION; ULTRAVIOLET; WAVES; SPECTRUM AB We present optical photometric and spectrophotometric observations of two selected filaments near the North rim of the Vela supernova remnant also observed in UV with the International Ultraviolet Explorer, and in X-rays with the ROSAT PSPC detector. From the optical data, we have derived spatially-resolved (similar to 3 ") profiles of several emission lines across the filaments, which allowed us to resolve the post-shock region. Starting from model-independent line ratio diagnostics, we have estimated densities ((n) over bar = 3.2 - 8.2 cm(-3)), temperatures (T = 3 - 10 x 10(4) K), pressures (P = 2.8 x 10(-10) dyne cm(-2)), and ambient magnetic fields (B = 50 - 85 mu G) in the post-shock flow. We have also found clear evidence of a relative displacement between the X-ray emission, the emission in the H alpha line and the emission in the [O III] line. We have compared the measured displacement, the width of the filaments in H alpha and [O III], and the peak values of selected line ratios with the predictions of a radiative shock model which describes in detail the structure of the post-shock region. Shock models with velocities around v(s) = 110 km sec(-1) are shown to be consistent with the optical and UV observations if we assume that the direction of propagation is tilted with respect to the line of sight. The layout of the X-ray and optical emission of the filament and their thermodynamical properties strongly suggest that the shock is travelling along increasing density gradient. C1 Osservatorio Astron Palermo GS Vaiana, I-90134 Palermo, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Bocchino, F (reprint author), European Space Agcy, Estec, Div Astrophys, POB 299, NL-2200 AG Noordwijk, Netherlands. EM fbocchin@estec.esa.nl RI Maggio, Antonio/P-5700-2015; OI Maggio, Antonio/0000-0001-5154-6108; Bocchino, Fabrizio/0000-0002-2321-5616 NR 41 TC 15 Z9 15 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUL PY 2000 VL 359 IS 1 BP 316 EP 336 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 338MT UT WOS:000088424400028 ER PT J AU Mineo, T Fiore, F Laor, A Costantini, E Brandt, WN Comastri, A Della Ceca, R Elvis, M Maccacaro, T Molendi, S AF Mineo, T Fiore, F Laor, A Costantini, E Brandt, WN Comastri, A Della Ceca, R Elvis, M Maccacaro, T Molendi, S TI BeppoSAX broad-band observations of low-redshift quasars: spectral curvature and iron K-alpha lines SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : quasars : general; galaxies : quasars : emission lines; X-rays : galaxies ID X-RAY-SPECTRA; MEDIUM SENSITIVITY SURVEY; ACTIVE GALACTIC NUCLEI; SEYFERT-GALAXY; ASCA; OBJECTS; SAMPLE; GINGA; AGN AB We present results from BeppoSAX observations of 10 low redshift quasars. The quasars are part of the Laor et al. (1997) sample of 23 optically selected PG quasars with redshift < 0.4 and low Galactic absorption along the line of sight. Significant spectral curvature is detected for the 6 quasars with the highest signal to noise ratio in their low energy spectra. The average curvature can be parameterized as a flattening of the underlying power law by Delta alpha similar to 0.5 above similar to 1 keV. We find that quasars with a steeper soft X-ray (0.1-2 keV) spectrum tend to be steeper also at higher (2-10 keV) energies. The distribution of the best fit 2-10 keV slopes is similar to that found for other radio-quiet AGN and characterized by a large dispersion around the mean: alpha(E) similar or equal to 1.0 +/- 0.3. Iron K-alpha lines are detected in 4 quasars. In the narrow-line quasar PG 1115+407, the rest frame line energy (6.69+/-0.11 keV) and equivalent width (580+/-280 eV) are consistent with these found in a few low redshift narrow-line Seyfert 1 galaxies (NLSy1). This, together with the similarity of the 0.1-10 keV X-ray continuum, suggests that this quasar is the higher redshift and luminosity analog of a NLSy 1. In the broad line quasar PG 0947+396, the rest-frame line energy suggests fluorescence from cold iron. The line equivalent width (> 400 eV) is however about 2-3 times higher than that usually found in Seyfert 1 galaxies. The high energy power-law slopes and the iron line emission properties seem to be unrelated to the X-ray luminosity. C1 CNR, Ist Fis Cosm & Applicazioni Informat, I-90146 Palermo, Italy. Telespazio, Beppo SAX Sci Data Ctr, I-00131 Rome, Italy. Osservatorio Astron Roma, I-00040 Monteporzio, RM, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Technion Israel Inst Technol, Dept Phys, IL-32000 Haifa, Israel. Osservatorio Astron Bologna, I-40127 Bologna, Italy. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Osservatorio Astron Brera, I-20121 Milan, Italy. CNR, Ist Fis Cosm & Tecnol Relat, I-20133 Milan, Italy. RP Mineo, T (reprint author), CNR, Ist Fis Cosm & Applicazioni Informat, La Malfa 153, I-90146 Palermo, Italy. EM mineo@ifcai.pa.cnr.it RI Brandt, William/N-2844-2015; Comastri, Andrea/O-9543-2015; OI Brandt, William/0000-0002-0167-2453; Comastri, Andrea/0000-0003-3451-9970; Mineo, Teresa/0000-0002-4931-8445 NR 47 TC 32 Z9 32 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUL PY 2000 VL 359 IS 2 BP 471 EP 482 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 341JJ UT WOS:000088587000010 ER PT J AU Tafalla, M Myers, PC Mardones, D Bachiller, R AF Tafalla, M Myers, PC Mardones, D Bachiller, R TI L483: a protostar in transition from Class 0 to Class I SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : formation; ISM : clouds; ISM : individual objects : L134N; ISM : jets and outflows; ISM : molecules ID YOUNG STELLAR OBJECTS; SUBMILLIMETER-WAVELENGTH OBSERVATIONS; FORMING DENSE CORES; L1157 DARK CLOUD; MOLECULAR OUTFLOW; BIPOLAR OUTFLOW; SIO EMISSION; CONTRACTING CLOUDS; EXCITING SOURCE; BOW SHOCK AB We present line observations of different molecular species toward the dense core in L483 and its bipolar outflow powered by the Class 0 object IRAS 18148-0440. (12)CO(2-1) maps show that the outflow is well collimated and asymmetric, and that its gas is warmer than the surrounding cloud by at least a factor of 2. In contrast with the outflows from other Class 0 objects, the CH(3)OH(2(k)-1(k)) lines in L483 do not show strong high velocity wings, although there is a small (similar to 0.3 km s(-1)) velocity shift approximately along the outflow direction. We do not find evidence for a CH(3)OH abundance enhancement in the flow, and the CH(3)OH lines trace a centrally concentrated core which Lye model, assuming optically thin emission, as having a density gradient between r(-1) and r(-1.5) for radii between 15 " and 100 ". H(2)CO(2(12)-1(11)) lines show strong high-velocity wings with the same distribution as the outflow, and evidence for a H(2)CO abundance enhancement of a factor of 20 with respect to the ambient cloud. At ambient velocities and over the central 40 ", this line presents a strong self absorption and a brighter blue peak, a characteristic signature of inward motions. A simple analysis of the H(2)CO line profiles suggests an infall rate of 2 x 10(-6) M(circle dot) yr(-1). Combining the results from our observations with previous work, we discuss the evolutionary status of IRAS 18148-0440 and its outflow. The bipolar outflow presents some characteristics common to other outflows from Class 0 sources, like high degree of collimation, gas heating, and H(2)CO abundance enhancement. However, other characteristics, like its low velocity, the lack of bright SiO or CH(3)OH outflow wings, and the association with a NIR scattering nebula (optically invisible) seem more common to outflows from the more evolved Class I sources. As IRAS 18148-0440 is a Class 0 object based on its spectral energy distribution, we propose that it is more evolved than other objects in its class, probably in transition from Class 0 to Class I. C1 Natl Astron Observ, Alcala De Henares 28800, Spain. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Chile, Dept Astron, Santiago, Chile. RP Tafalla, M (reprint author), Natl Astron Observ, Apartado 1143, Alcala De Henares 28800, Spain. RI Mardones, Diego/I-5719-2016 NR 61 TC 47 Z9 47 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JUL PY 2000 VL 359 IS 3 BP 967 EP 976 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 341JZ UT WOS:000088588400016 ER PT J AU White, M Hu, W AF White, M Hu, W TI A new algorithm for computing statistics of weak lensing by large-scale structure SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : theory; gravitational lensing; large-scale structure of universe ID POWER SPECTRUM; EVOLUTION AB We describe an efficient algorithm for calculating the statistics of weak lensing by large-scale structure based on a tiled set of independent particle-mesh N-body simulations that telescope in resolution along the line of sight. This efficiency allows us to predict not only the mean properties of lensing observables such as the power spectrum, skewness and kurtosis of the convergence, but also their sampling errors for finite fields of view, which are themselves crucial for assessing the cosmological significance of observations. We find that the non-Gaussianity of the distribution substantially increases the sampling errors for the skewness and kurtosis in the several to tens of arcminutes regime, whereas those for the power spectrum are only fractionally increased even out to wavenumbers where shot noise from the intrinsic ellipticities of the galaxies will likely dominate the errors. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Inst Adv Study, Princeton, NJ 08540 USA. RP White, M (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI White, Martin/I-3880-2015 OI White, Martin/0000-0001-9912-5070 NR 33 TC 104 Z9 105 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2000 VL 537 IS 1 BP 1 EP 11 DI 10.1086/309009 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 337PN UT WOS:000088371000001 ER PT J AU Ungerechts, H Umbanhowar, P Thaddeus, P AF Ungerechts, H Umbanhowar, P Thaddeus, P TI A CO survey of giant molecular clouds near Cassiopeia A and NGC 7538 SO ASTROPHYSICAL JOURNAL LA English DT Article DE Galaxy : structure; ISM : clouds; ISM : individual (NGC 7538); ISM : molecules ID GAMMA-RAY EMISSION; RADIAL-DISTRIBUTION; LINEAR-REGRESSION; OUTER GALAXY; SOLAR CIRCLE; PERSEUS ARM; SPIRAL ARM; MILKY-WAY; ASTRONOMY; GAS AB With the 1.2 m telescope at the Center for Astrophysics we have undertaken a survey of the J = 1 --> 0 CO line toward the conspicuous complex of giant molecular clouds (GMCs) in the Perseus arm in the region of Cas A and NGC 7538. The survey, at a spectral resolution of 250 kHz (0.65 km s(-1)), on a uniform grid of points spaced every 0.degrees 125 in latitude and longitude, covers 55 deg(2) between I = 107 degrees and 116 degrees A smaller area of approximate to 15 deg(2) between l = 108 degrees and 113 degrees was similarly surveyed in (CO)-C-13. I, the region covered in both isotopic species we find at least seven GMCs with masses on the order of 10(5) M-circle dot. An intensity-weighted radius gives a more meaningful measure of cloud size than the simple geometrical area and is best used to estimate the virial mass. The ratio of total cloud luminosities in CO and (CO)-C-13, S-12/S-13, ranges from 6 to 10, with a mean of 8.5. The distribution of molecular gas is very similar in CO and (CO)-C-13, and the velocity-integrated intensities at each point are closely correlated. In the (I, v)-diagram the Perseus arm is kinematically separated from the local arm by an interarm gap that is nearly free of CO; the contrast in molecular gas surface density between the Perseus arm and the interarm gap is apparently at least 20. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Ungerechts, H (reprint author), IRAM, Ave Divina Pastora 7, E-18012 Granada, Spain. NR 35 TC 34 Z9 35 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2000 VL 537 IS 1 BP 221 EP 235 DI 10.1086/308992 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 337PN UT WOS:000088371000019 ER PT J AU Cranmer, SR Smith, MA Robinson, RD AF Cranmer, SR Smith, MA Robinson, RD TI A multiwavelength campaign on gamma cassiopeiae. IV. The case for illuminated disk-enhanced wind streams SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; line : profiles; stars : early-type; stars : emission-line, Be; stars : individual (gamma Cassiopeiae); stars : winds, outflows ID COROTATING INTERACTION REGIONS; RADIATION-DRIVEN WINDS; ONE-ARMED OSCILLATIONS; LONG-TERM VARIABILITY; BE-STAR ATMOSPHERES; STELLAR WINDS; X-RAY; O-STARS; DYNAMIC PROCESSES; FAR-UV AB On 1996 March 14-15 we conducted a campaign with the Hubble Space Telescope GHRS to observe the Si lambda lambda 1394, 1403 lines of the B0.5e star gamma Cas at high temporal and spectral resolution. As a part of this similar to 22 hr campaign, the Rossi X-Ray Timing Explorer (RXTE) was also used to monitor this star's copious and variable X-ray emission. In this fourth paper of a series we present an analysis of the rapid variations of the discrete absorption components (DACs) of the Si Iv doublet. The DACs attain a maximum absorption at -1280 km s(-1), taper at higher velocities, and extend to -1800 km s(-1). The DACs in this star's resonance lines have been shown to be correlated with a greater than or similar to 6 yr cycle in the Balmer line emission VIR ratio, and in 1996 this DAC strength was near its maximum. We derive hydrogen densities of 10(9)-10(10) cm(-3) in the DAC material using a curve-of-growth method and find that the plasma becomes marginally optically thick near -1280 km s(-1). The "mean DAC" probably represents a broad "plateau" with a volume density intermediate between the star's midlatitude wind and equatorial disk. We also follow the blueward evolution of subfeatures in the DACs. These features appear to emanate primarily from one or two discrete azimuths on the star and accelerate much more slowly than expected for the background wind, thereby exhibiting an enhanced opacity spiral stream pattern embedded within the structure forming the DAC. In the first two papers in this series, we suggested that active X-ray centers are associated with at least two major cool clouds forced into corotation. Several correlations of flickering in the Si rv DACs are found in our data, which support the idea that changes in X-ray ionizing flux cause changes in the ionization of material at various sectors along the spiral pattern. We demonstrate that similar flickering is visible in archival IUE data from 1982 and may also be responsible for earlier reports from Copernicus of rapid changes in this star's UV and optical lines. Finally, we discovered that flickering of the DAC fluxes in the 1982 data is correlated with rotation phase and shows a modulation with a 7.5 hr cyclical cessation of X-ray flares that was observed recently by RXTE. This confirms our basic picture that lulls in X-ray activity close to the star's surface cause both a lower Si v ionization fraction and an increase in Si Iv variability within the DAC structures. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Space Telescope Sci Inst, CSC, STScI, Baltimore, MD 21218 USA. NASA, Goddard Space Flight Ctr, LASP, Greenbelt, MD 20771 USA. Catholic Univ Amer, Washington, DC 20064 USA. RP Cranmer, SR (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 88 TC 21 Z9 21 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2000 VL 537 IS 1 BP 433 EP 447 DI 10.1086/309008 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 337PN UT WOS:000088371000042 ER PT J AU Tomsick, JA Kaaret, P AF Tomsick, JA Kaaret, P TI X-ray spectral and timing evolution during the decay of the 1998 outburst from the recurrent X-ray transient 4U 1630-47 SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; stars : individual (4U 1630-47); X-rays : bursts; X-rays : stars ID QUASI-PERIODIC OSCILLATIONS; GRO J1655-40; NOVA-MUSCAE; HIGH STATE; 4U-1630-47; GS-1124-683; ACCRETION AB We report on the X-ray spectral and timing behavior of the recurrent X-ray transient 4U 1630-47 for 51 Rossi X-Ray Timing Explorer (RXTE) observations made during the decay of its 1998 outburst. The observations began when the source was still relatively bright, and during one of the early observations, a quasi-periodic oscillation (QPO) with a non-Lorentzian profile occurred near 6 Hz. As the source decayed, the X-ray flux dropped exponentially with an e-folding time of 14.3 days. The exponential decay was interrupted by an increase in the X-ray flux, and a secondary maximum occurred 89 days after the onset of the outburst. A transition marked by significant changes in the timing and spectral properties of the source occurred 104 days after the start of the outburst. The transition is similar to soft-to-hard state transitions observed in other black hole candidate X-ray binaries. Most of the changes associated with the transition occurred in less than 2 days. The timing changes include an increase in the continuum noise level from less than 4% rms to greater than 10% rms and the appearance of a QPO at 3.4 Hz with an rms amplitude of 7.3% in the 2-21 keV energy band. At the transition, the energy spectrum also changed with an abrupt drop in the soft component flux in the RXTE bandpass. A change in the power-law photon index from 2.3 to 1.8, also associated with the transition, occurred over a time period of 8 days. After the transition, the source flux continued to decrease, and the QPO frequency decayed gradually from 3.4 Hz to about 0.2 Hz. C1 Columbia Univ, Dept Phys, New York, NY 10027 USA. Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Tomsick, JA (reprint author), Univ Calif San Diego, Ctr Astrophys & Space Sci, MS 0424, La Jolla, CA 92093 USA. NR 49 TC 37 Z9 37 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2000 VL 537 IS 1 BP 448 EP 460 DI 10.1086/308999 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 337PN UT WOS:000088371000043 ER PT J AU Garcia, MR Murray, SS Primini, FA Forman, WR McClintock, JE Jones, C AF Garcia, MR Murray, SS Primini, FA Forman, WR McClintock, JE Jones, C TI A first look at the nuclear region of M31 with Chandra SO ASTROPHYSICAL JOURNAL LA English DT Article DE black hole physics; galaxies : individual (M31) ID X-RAY SOURCES; BLACK-HOLE; RADIO; CALIBRATION; EMISSION AB We report on the first observation of the nuclear region of M31 with the Chandra X-Ray Observatory. The nuclear source seen with the Einstein and ROSAT HRIs is resolved into five point sources. One of these sources is within 1 " of the M31 central supermassive black hole. As compared to the other point sources in M31, this nuclear source has an unusual X-ray spectrum. Based on the spatial coincidence, we speculate that this source is associated with the central black hole and note that the unusual spectrum is a challenge to some current theories. A bright transient is detected similar to 26 " to the west of the nucleus and may be associated with a stellar mass black hole. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Garcia, MR (reprint author), Harvard Smithsonian Ctr Astrophys, MS-4,60 Garden St, Cambridge, MA 02138 USA. NR 32 TC 41 Z9 41 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2000 VL 537 IS 1 BP L23 EP L26 DI 10.1086/312751 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 337PP UT WOS:000088371100006 ER PT J AU Haiman, Z Spaans, M Quataert, E AF Haiman, Z Spaans, M Quataert, E TI Ly alpha cooling radiation from high-redshift halos SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : theory; early universe; galaxies : evolution; galaxies : ISM ID GALAXY FORMATION; DISK GALAXIES; CONDENSATION; CLUSTERS; MODELS AB The baryons inside high-redshift halos with virial temperatures T greater than or similar to 10(4) K cool radiatively as they condense inside dark matter potential wells. We show that the release of the gravitational binding energy, over the halo assembly timescale, results in a significant and detectable Ly alpha flux. At the limiting line flux approximate to 10(-19) ergs s(-1) cm(-2) arcsec(-2) of the Next Generation Space Telescope, several sufficiently massive halos, with velocity dispersions sigma greater than or similar to 120 km s(-1), would be visible per 4' x 4' field. The halos would have characteristic angular sizes of approximate to 10 ", would be detectable in a broadband survey out to z approximate to 6-8, and would provide a direct probe of galaxies in the process of forming. They may be accompanied by He+ Ly alpha emission at the approximate to 10% level, but remain undetectable at other wavelengths. Our predictions are in good agreement with the recent finding of two Ly alpha "blobs" at z = 3.1 by Steidel et al. C1 Princeton Univ Observ, Princeton, NJ 08544 USA. Univ Calif Santa Barbara, Inst Theoret Phys, Santa Barbara, CA 93106 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Inst Adv Study, Sch Nat Sci, Princeton, NJ 08540 USA. RP Haiman, Z (reprint author), Princeton Univ Observ, Ivy Lane, Princeton, NJ 08544 USA. NR 21 TC 110 Z9 110 U1 1 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2000 VL 537 IS 1 BP L5 EP L8 DI 10.1086/312754 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 337PP UT WOS:000088371100002 ER PT J AU Igumenshchev, IV Abramowicz, MA Narayan, R AF Igumenshchev, IV Abramowicz, MA Narayan, R TI Numerical simulations of convective accretion flows in three dimensions SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; convection; hydrodynamics; turbulence ID ADVECTION-DOMINATED ACCRETION; BLACK-HOLES; DISKS AB Advection-dominated accretion flows (ADAFs) are known to be convectively unstable for low values of the viscosity parameter a. Two-dimensional axisymmetric hydrodynamic simulations of such flows reveal a radial density profile that is significantly flatter than the rho proportional to r(-3/2) expected for a canonical ADAF. The modified density profile is the result of inward transport of angular momentum by axisymmetric convective eddies. We present three-dimensional hydrodynamic simulations of convective ADAFs that are free of the assumption of axisymmetry. We find that the results are qualitatively and quantitatively similar to those obtained with two-dimensional simulations. In particular the convective eddies are nearly axisymmetric and transport angular momentum inward. C1 Gothenburg Univ, Inst Theoret Phys, S-41296 Gothenburg, Sweden. Chalmers Univ Technol, S-41296 Gothenburg, Sweden. Inst Astron, Moscow, Russia. SISSA, Lab Interdisciplinare, I-34014 Trieste, Italy. ICTP, I-34014 Trieste, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Igumenshchev, IV (reprint author), Gothenburg Univ, Inst Theoret Phys, S-41296 Gothenburg, Sweden. NR 13 TC 75 Z9 75 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUL 1 PY 2000 VL 537 IS 1 BP L27 EP L30 DI 10.1086/312755 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 337PP UT WOS:000088371100007 ER PT J AU Argon, AL Reid, MJ Menten, KM AF Argon, AL Reid, MJ Menten, KM TI Interstellar hydroxyl masers in the galaxy. I. The VLA survey SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE HII regions; ISM : clouds; masers; radio lines : ISM ID OH MASERS; H2O MASERS; REGIONS; POSITIONS; W3(OH); MAIN; MHZ AB Interstellar OH masers are bright signposts for recently formed massive stars, and the maser emission can be used to study the kinematic and physical conditions of dense molecular material surrounding these stars. We present interferometric maps of 91 interstellar OH maser sources in one or both of the ground-state, main-line, 2 Pi (3/2) J = 3/2 OH transitions near 18 cm wavelength. The maps comprising this large, uniformly processed, survey have a spectral resolution of 0.14 km s(-1) and an angular resolution of approximate to 1."5. We measured the absolute positions of the masers to an accuracy of approximate to0."3 in the E-W direction and approximate to0."5 in the N-S direction, except for those sources with declinations below about -30 degrees, and relative positions of isolated OH maser spots within each source and OH transition to an accuracy of approximate to 0." 01. This survey forms a nearly complete sample of interstellar OH masers that are stronger than 1 Jy in both right- and left-circular polarization in at least one of the ground-state OH transitions. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Max Planck Inst Radioastron, D-53121 Bonn, Germany. RP Argon, AL (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 29 TC 123 Z9 124 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD JUL PY 2000 VL 129 IS 1 BP 159 EP 227 DI 10.1086/313406 PG 69 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 365MC UT WOS:000089954200008 ER PT J AU Monnier, JD Fitelson, W Danchi, WC Townes, CH AF Monnier, JD Fitelson, W Danchi, WC Townes, CH TI Mid-infrared interferometry on spectral lines. I. Instrumentation SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE instrumentation : interferometers; instrumentation : spectrographs; techniques : interferometric ID EMISSION AB The Infrared Spatial Interferometer at University of California, Berkeley has been outfitted with a filter-bank system to allow interferometric observations of mid-infrared spectral lines with very high spectral resolution (lambda/Delta lambda similar to 10(5)). This paper describes the design, implementation, and performance of the matched 32 channel filter-bank modules, and new spectral-line observations of Mars and IRC + 10216 are used to demonstrate their scientific capability. In addition, observing strategies are discussed for accurate calibration of fringe visibilities in spectral lines, despite strong atmospheric fluctuations encountered in the infrared. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Monnier, JD (reprint author), Smithsonian Astrophys Observ MS 42, 60 Garden St, Cambridge, MA 02138 USA. NR 15 TC 10 Z9 10 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD JUL PY 2000 VL 129 IS 1 BP 421 EP 429 DI 10.1086/313417 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 365MC UT WOS:000089954200019 ER PT J AU Clarsen, G AF Clarsen, G TI The 'dainty female toe' and the 'brawny male arm': Conceptions of bodies and power in automobile technology SO AUSTRALIAN FEMINIST STUDIES LA English DT Article C1 Smithsonian Inst, Natl Museum Amer Hist, Washington, DC 20560 USA. RP Clarsen, G (reprint author), Smithsonian Inst, Natl Museum Amer Hist, Washington, DC 20560 USA. NR 26 TC 5 Z9 5 U1 0 U2 0 PU CARFAX PUBLISHING PI BASINGSTOKE PA RANKINE RD, BASINGSTOKE RG24 8PR, HANTS, ENGLAND SN 0816-4649 J9 AUST FEMINIST STUD JI Aust. Fem. Stud. PD JUL PY 2000 VL 15 IS 32 BP 153 EP 163 DI 10.1080/08164640050138671 PG 11 WC Women's Studies SC Women's Studies GA 358RJ UT WOS:000089570700003 ER PT J AU Wolf, KN Wildt, DE Vargas, A Marinari, PE Kreeger, JS Ottinger, MA Howard, JG AF Wolf, KN Wildt, DE Vargas, A Marinari, PE Kreeger, JS Ottinger, MA Howard, JG TI Age-dependent changes in sperm production, semen quality, and testicular volume in the black-footed ferret (Mustela nigripes) SO BIOLOGY OF REPRODUCTION LA English DT Article DE aging; Leydig cells; male sexual function; sperm; testosterone ID BROWN-NORWAY RAT; CELL TESTOSTERONE PRODUCTION; LUTEINIZING-HORMONE; SERUM CONCENTRATIONS; REPRODUCTION; MORPHOLOGY; EPIDIDYMIS; MEN; GONADOTROPIN; INSEMINATION AB The black-footed ferret (Mustela nigripes), which was extirpated from its native North American prairie habitat during the 1980s, is being reintroduced to the wild because of a successful captive-breeding program. To enhance propagation, the reproductive biology of this endangered species is being studied intensively. The typical life span of the black-footed ferret is approximately 7 yr. Female fecundity declines after 3 yr of age, but the influence of age on male reproduction is unknown. In this study, testis volume, seminal traits, sperm morphology, and serum testosterone were compared in 116 males from 1 to 7 yr of age living in captivity. Results demonstrated that testes volume during the peak breeding season was similar (P > 0.05) among males 1 to 5 yr of age, reduced (P < 0.05) among males 6 yr of age, and further reduced (P < 0.05) among males 7 yr of age. Motile sperm/ejaculate was similar in males 1 to 6 yr of age but diminished (P < 0.05) in those 7 yr of age. Males at 6 and 7 yr of age produced fewer (P < 0.05) structurally normal sperm than younger counterparts; however, serum testosterone concentrations were not reduced (P > 0.05) in older males. Histological comparison of testicular/epididymal tissue from 5- and 7-yr-old black-footed ferrets confirmed that the interval between these two ages may represent a transitional period to reproductive senescence. In summary, functional reproductive capacity of male black-footed ferrets exceeds that of females by at least 2 yr. Testes and seminal quality are indistinguishable among males 1 to 5 yr of age, with progressive reproductive aging occurring thereafter. C1 Smithsonian Inst, Natl Zool Pk, Conservat & Res Ctr, Front Royal, VA 22630 USA. US Fish & Wildlife Serv, Natl Black Footed Ferret Conservat Ctr, Laramie, WY 82070 USA. Univ Maryland, College Pk, MD 20742 USA. RP Howard, JG (reprint author), Smithsonian Inst, Natl Zool Pk, Reprod Physiol Program, Washington, DC 20008 USA. NR 63 TC 34 Z9 35 U1 5 U2 20 PU SOC STUDY REPRODUCTION PI MADISON PA 1603 MONROE ST, MADISON, WI 53711-2021 USA SN 0006-3363 J9 BIOL REPROD JI Biol. Reprod. PD JUL PY 2000 VL 63 IS 1 BP 179 EP 187 DI 10.1095/biolreprod63.1.179 PG 9 WC Reproductive Biology SC Reproductive Biology GA 327UP UT WOS:000087812400026 PM 10859258 ER PT J AU Strong, MT AF Strong, MT TI A new species of Rhynchospora section Tenues Kukenthal (Cyperaceae) from Puerto Rico SO BRITTONIA LA English DT Article DE Cyperaceae; Rhynchospora sect. Tenues; West Indies; Greater Antilles; Puerto Rico AB Strong, M. T. (Smithsonian Institution, Department of Botany, MRC-166, Washington, DC 20560-0166, U.S.A.). A new species of Rhynchospora section Tenues Kukenthal (Cyperaceae) from Puerto Rico. Brittonia 52: 241-245. 2000.-Rhynchospora depressirostris M. Strong, an overlooked species of Rhynchospora sect. Tenues Kukenthal, previously treated in the literature as R. tenuis Link, is described from Puerto Rico. An illustration and SEM images of the achene (fruit) are provided, and its relationship to closely allied and morphologically similar species is discussed. C1 Smithsonian Inst, Dept Bot, Washington, DC 20560 USA. RP Strong, MT (reprint author), Smithsonian Inst, Dept Bot, MRC-166, Washington, DC 20560 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU NEW YORK BOTANICAL GARDEN PI BRONX PA PUBLICATIONS DEPT, BRONX, NY 10458 USA SN 0007-196X J9 BRITTONIA JI Brittonia PD JUL-SEP PY 2000 VL 52 IS 3 BP 241 EP 245 DI 10.2307/2666574 PG 5 WC Plant Sciences SC Plant Sciences GA 387QN UT WOS:000166133400005 ER PT J AU Fauchald, K AF Fauchald, K TI Carl Stop-Bowitz (1914-1997) - Obituary SO BULLETIN OF MARINE SCIENCE LA English DT Biographical-Item C1 Smithsonian Inst, Natl Museum Nat Hist, Washington, DC 20560 USA. RP Fauchald, K (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Washington, DC 20560 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD JUL PY 2000 VL 67 IS 1 BP 10 EP 10 PG 1 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 370RV UT WOS:000165136800004 ER PT J AU Radashevsky, VI Fauchald, K AF Radashevsky, VI Fauchald, K TI Chaetal arrangement and homology in spionids (Polychaeta : Spionidae) SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT 6th International Polychaete Conference CY AUG 02-07, 1998 CL CURITIBA, BRAZIL AB In anterior segments of spionid polychaetes notochaetae are generally capillaries arranged in three distinct groups or rows including an anterior and a posterior row and a dorsal superior tuft; neurochaetae are also capillaries arranged in anterior and posterior rows plus a ventral inferior tuft. In succeeding segments, the notopodial capillaries are reduced in number with the groups becoming indistinct, the neuropodial capillaries are usually replaced by hooks in differing patterns. These patterns of replacement include those with replacement only in the posterior row, in both anterior and posterior rows, or of all neuropodial capillaries. A pattern of alternating neuropodial capillaries alternating with the neuropodial hooks is described for the first time. In most polydorid taxa the chaetal arrangement on segment 5 is changed from a vertical to a diagonal or horizontal position, presumably associated with the elongation of the segment. The modified chaetae are usually arranged in two curved diagonal or horizontal rows corresponding to the anterior and posterior rows of notochaetae in other spionids. Based on positional criteria different kinds of spionid chaetae can be shown to be homologous making it possible to code them consistently for a cladistic analysis. C1 Smithsonian Inst, Natl Museum Nat Hist, Washington, DC 20560 USA. Inst Marine Biol, Vladivostok 690041, Russia. RP Fauchald, K (reprint author), Smithsonian Inst, Natl Museum Nat Hist, Washington, DC 20560 USA. NR 12 TC 21 Z9 22 U1 0 U2 1 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD JUL PY 2000 VL 67 IS 1 BP 13 EP 23 PG 11 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 370RV UT WOS:000165136800007 ER PT J AU Li, CS Hueber, FM Hotton, CL AF Li, CS Hueber, FM Hotton, CL TI A neotype for Drepanophycus spinaeformis Goppert 1852 SO CANADIAN JOURNAL OF BOTANY-REVUE CANADIENNE DE BOTANIQUE LA English DT Article DE Drepanophycus; neotype; lycopsid; cauline sporangia; Lower Devonian; Canada AB The species Drepanophycus spinaeformis Goppert 1852 was described as a fossil plant closely allied with the fucoid algae. Many years later the type, a single figured specimen, was lost along with its associated collection. Subsequent studies described and assigned additional fossils to the species and redefined it as a land plant, a lycopsid. Through all of the descriptions and assignments of specimens to the species, no single specimen was designated as the type to bear the name in the absence of a holotype. The purpose of this paper is to designate a specimen as the neotype, the bearer of the name, and to emend the taxonomic description of the species. C1 Smithsonian Inst, Dept Paleobiol, Washington, DC 20560 USA. Chinese Acad Sci, Inst Bot, Dept Paleobot, Lab Systemat & Evolutionary Bot, Beijing 100093, Peoples R China. Natl Lib Med, Natl Ctr Biotechnol Informat, NIH, Bethesda, MD 20894 USA. RP Hueber, FM (reprint author), Smithsonian Inst, Dept Paleobiol, MRC 121, Washington, DC 20560 USA. NR 28 TC 18 Z9 19 U1 0 U2 4 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0008-4026 J9 CAN J BOT JI Can. J. Bot.-Rev. Can. Bot. PD JUL PY 2000 VL 78 IS 7 BP 889 EP 902 PG 14 WC Plant Sciences SC Plant Sciences GA 343GZ UT WOS:000088694700005 ER PT J AU Dreizin, EL Berman, CH Vicenzi, EP AF Dreizin, EL Berman, CH Vicenzi, EP TI Condensed-phase modifications in magnesium particle combustion in air SO COMBUSTION AND FLAME LA English DT Article ID ALUMINUM AB Free-falling individual magnesium particles were produced and ignited using a pulsed micro-are and burned in air. Particle combustion temperatures were monitored in real time using a three-color pyrometer. Black-body and MgO radiation histories were separated using interference filters and compared with each other. Particles were rapidly quenched at different combustion rimes and their elemental compositions were studied using energy and wavelength dispersive spectroscopy techniques. Particle combustion times and radiation histories were consistent with those reported previously. Measurements of the elemental compositions of quenched particles showed substantial amounts of dissolved oxygen, consistent with recent metal particle combustion studies using the same experimental technique. An estimate based on the rate constants reported in the literature for the magnesium vapor-phase burning, showed that the reaction rate is insufficiently fast to prevent oxygen gas diffusion through the vapor-phase stand-off flame to the particle surface. A combustion mechanism is discussed in which oxygen approaching the surface of a burning particle is dissolved in magnesium producing a new liquid-phase Mg-O solution. The heterogeneous reaction of oxygen dissolution begins simultaneously with the vapor-phase combustion and later on the heterogeneous reaction becomes the primary combustion mechanism. After the solution becomes saturated, an exothermic phase transformation, Mg-O-solution --> Mg + MgO, occurs that contributes to the production of large amounts of oxide detected on the surfaces of partially burned particles and causes the observed oscillations and peaks in particle radiation. (C) 2000 by The Combustion Institute. C1 New Jersey Inst Technol, Dept Mech Engn, Newark, NJ 07102 USA. Titan Corp, AeroChem Res Lab, Princeton, NJ USA. Smithsonian Inst, Dept Mineral Sci, Washington, DC 20560 USA. RP Dreizin, EL (reprint author), New Jersey Inst Technol, Dept Mech Engn, Newark, NJ 07102 USA. RI Dreizin, Edward/O-6416-2014; OI Dreizin, Edward/0000-0003-0859-0984 NR 25 TC 20 Z9 21 U1 0 U2 12 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD JUL PY 2000 VL 122 IS 1-2 BP 30 EP 42 DI 10.1016/S0010-2180(00)00101-2 PG 13 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 322QM UT WOS:000087520300003 ER PT J AU Valladares, F Wright, SJ Lasso, E Kitajima, K Pearcy, RW AF Valladares, F Wright, SJ Lasso, E Kitajima, K Pearcy, RW TI Plastic phenotypic response to light of 16 congeneric shrubs from a Panamanian rainforest SO ECOLOGY LA English DT Article DE Barro Colorado Island, Panama; leaf longevity; light acclimation; phenotypic plasticity; predictability of environmental change; Psychotria; stress syndrome; tropical forest ID TROPICAL RAIN-FOREST; SUBGENUS PSYCHOTRIA RUBIACEAE; LEAF LIFE-SPAN; PHOTOSYNTHETIC RESPONSES; PHYSIOLOGICAL ECOLOGY; DROUGHT ACCLIMATION; FIELD CONDITIONS; SHADE-TOLERANCE; TREE SEEDLINGS; CANOPY GAPS AB The comparative phenotypic plasticity of 16 species of tropical rainforest shrubs (genus Psychotria, Rubiaceae) was investigated by growing plants in three light environments on Barro Colorado Island (BCI, Panama). The three light environments gave daily photon flux densities (PPFD) similar to the natural light gradient from shaded forest understory to small and large canopy gaps. Six of the species are principally found in gaps or forest edge environments, whereas the other ten species are principally found in shaded understories. Interactions between light treatment and species resulted in unpredictable mean phenotypic expression across light treatments. Shoot relative growth rates (RGR) were similar for understory and gap species in the low light treatment. Gap species had significantly greater shoot RGR in the intermediate light treatment than in the high light treatment. Mean plasticity was significantly lower for morphological variables when com pared to physiological variables, while variation in plasticity was significantly greater for structural variables. Significant differences between gap and understory species were found in the plasticity of six out of the seven variables. The mean phenotypic plasticity of the seven variables was significantly greater for gap than for understory species. The high plasticity of gap species was consistent with the hypothesis that specialization in a more favorable environment increases plasticity. The species exhibited a wide range of leaf longevities, from four to 29 months, with gap species having, on average, shorter leaf lifespan than understory species. Mean phenotypic plasticity decreased with increasing leaf longevity. Selection for greater plasticity may be stronger in the gap species because gaps exhibit a relatively predictable decrease in PPFD for which plasticity could be adaptive. While we have found a significant correlation between phenotypic plasticity and habitat affiliation, phylogeny (subgenus ascription) was not correlated with plasticity or with plant performance in any given PPFD treatment, reinforcing the hypothesis that phenotypic plasticity has evolved through natural selection in this diverse genus. C1 CSIC, Ctr Ciencias Medioambientales, E-28006 Madrid, Spain. Smithsonian Trop Res Inst, Balboa, Ancon, Panama. Univ Calif Davis, Div Biol Sci, Sect Evolut & Ecol, Davis, CA 95616 USA. RP Valladares, F (reprint author), CSIC, Ctr Ciencias Medioambientales, Serrano 115 Departado, E-28006 Madrid, Spain. EM valladares@ccma.csic.es RI Kitajima, Kaoru/E-8877-2012; Wright, Stuart/M-3311-2013; Valladares, Fernando/K-9406-2014; OI Wright, Stuart/0000-0003-4260-5676; Valladares, Fernando/0000-0002-5374-4682; Lasso, Eloisa/0000-0003-4586-8674 NR 64 TC 329 Z9 415 U1 12 U2 96 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1990 M STREET NW, STE 700, WASHINGTON, DC 20036 USA SN 0012-9658 EI 1939-9170 J9 ECOLOGY JI Ecology PD JUL PY 2000 VL 81 IS 7 BP 1925 EP 1936 DI 10.1890/0012-9658(2000)081[1925:PPRTLO]2.0.CO;2 PG 12 WC Ecology SC Environmental Sciences & Ecology GA 334YQ UT WOS:000088214400014 ER PT J AU Apanius, V Yorinks, N Bermingham, E Ricklefs, RE AF Apanius, V Yorinks, N Bermingham, E Ricklefs, RE TI Island and taxon effects in parasitism and resistance of Lesser Antillean birds SO ECOLOGY LA English DT Article DE blood parasites; Haemoproteus; hematozoans; host-parasite interactions; immune response; Lesser Antilles; leukocyte counts; papilloma virus; Sarcocystis ID MITOCHONDRIAL-DNA; BLOOD PARASITES; GENE GENEALOGY; POPULATIONS; EPIZOOTIOLOGY; HAEMOPROTEUS; HAEMOSPORINA; APICOMPLEXA; PREVALENCE; DIVERGENCE AB Patterns of parasitism in insular avian communities can provide insight into processes that maintain host-parasite associations. On one hand, replicable relationships within evolutionarily independent communities of the same host and parasite taxa would indicate that these interactions are stable over time. On the other hand, unique ecological conditions on each island, sporadic colonizations and extinctions, plus new genetic variation would lead to island-specific host-parasite relationships. We examined the: distribution of three parasitic taxa among avian host species on three islands in the Lesser Antilles: St. Lucia, Martinique, and Dominica. Blood protozoa of the genus Haemoproteus were found in 34% of host individuals examined. A significant species effect, but no significant island effect, was observed, suggesting an ecologically stable and replicable host-parasite association. Cysts of the tissue-dwelling protozoan genus Sarcocystis were observed in 4% (9% on Dominica) of host individuals and were significantly associated with ground foraging. Epithelial lesions characteristic of avian papilloma virus were recorded in 4% of host individuals on Martinique only. The pattern of infection with papilloma virus or Sarcocystis (significant island effect) indicated that host species on a particular island are linked in transmission webs of these parasites. Such island-specific associations suggest a role for either history or unique local ecology in host-parasite associations. There was a statistically significant interaction between island and species effects in the prevalence of Haemoproteus. This may stem from the independent evolution of host-parasite interactions in the different island populations. We were able to assess the extent of genetic divergence of the host species by analysis of mitochondrial ATPase 6,8 sequences. There was little genetic divergence between island populations of the host species. Therefore, the variation in Haemoproteus prevalence is not likely to be related to genetic differentiation of the host populations. Birds infected with Haemoproteus exhibited elevated leukocyte levels indicative of immunological control of the parasite. After statistically controlling for the intensity of Haemoproteus infection and host species, leukocyte levels varied significantly among islands on which the host resided. This is consistent with the idea that insular avian communities are linked by transmission webs of parasites having broad host specificity. C1 Univ Penn, Dept Biol, Leidy Labs, Philadelphia, PA 19104 USA. Smithsonian Trop Res Inst, Unit 0948, APO, AA 34002 USA. RP Apanius, V (reprint author), Florida Int Univ, Dept Biol Sci, Univ Pk, Miami, FL 33199 USA. NR 57 TC 63 Z9 64 U1 1 U2 9 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1707 H ST NW, STE 400, WASHINGTON, DC 20006-3915 USA SN 0012-9658 J9 ECOLOGY JI Ecology PD JUL PY 2000 VL 81 IS 7 BP 1959 EP 1969 DI 10.1890/0012-9658(2000)081[1959:IATEIP]2.0.CO;2 PG 11 WC Ecology SC Environmental Sciences & Ecology GA 334YQ UT WOS:000088214400017 ER PT J AU Arnold, AE Maynard, Z Gilbert, GS Coley, PD Kursar, TA AF Arnold, AE Maynard, Z Gilbert, GS Coley, PD Kursar, TA TI Are tropical fungal endophytes hyperdiverse? SO ECOLOGY LETTERS LA English DT Article DE Barro Colorado Island; fungal endophytes; host preference; Jaccard's index; Ochnaceae; Olacaceae; Panama; tropical forests ID RAIN-FOREST; HOST PLANTS; PUERTO-RICO; DIVERSITY; BIODIVERSITY; LEAVES; ASSOCIATIONS; MICROFUNGI; POPULATION; SPECIATION AB Fungal endophytes are ubiquitous fungi that inhabit healthy plant tissues without causing disease. Endophytes have been found in every plant species examined to date and may be important, but often overlooked, components of fungal biodiversity. In two sites in a lowland, moist tropical forest of central Panama, we quantified endophyte colonization patterns, richness, host preference, and spatial variation in healthy leaves of two co-occurring, understory tree species [Heisteria concinna (Olacaceae) and Ouratea lucens (Ochnaceae)]. From 83 leaves, all of which were colonized by endophytes, we isolated 418 endophyte morphospecies (estimated 347 genetically distinct taxa), most of which were represented by only a single isolate (59%). Among morphospecies encountered in more than one leaf (nonsingletons), we found evidence of host preference and spatial heterogeneity using both morphospecies frequencies and presence/absence records. Based on these data, we postulate that tropical endophytes themselves may be hyperdiverse and suggest that extrapolative estimates that exclude them will markedly underestimate fungal species diversity. C1 Univ Arizona, Dept Ecol & Evolutionary Biol, Tucson, AZ 85721 USA. Smithsonian Trop Res Inst, Balboa, Panama. Univ Calif Santa Cruz, Dept Environm Studies, Santa Cruz, CA 95064 USA. Univ Utah, Dept Biol, Salt Lake City, UT 84112 USA. RP Arnold, AE (reprint author), Univ Arizona, Dept Ecol & Evolutionary Biol, Tucson, AZ 85721 USA. NR 52 TC 332 Z9 383 U1 6 U2 69 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 1461-023X J9 ECOL LETT JI Ecol. Lett. PD JUL PY 2000 VL 3 IS 4 BP 267 EP 274 DI 10.1046/j.1461-0248.2000.00159.x PG 8 WC Ecology SC Environmental Sciences & Ecology GA 343HW UT WOS:000088697800004 ER PT J AU Calderon, AI Angerhofer, CK Pezzuto, JM Farnsworth, NR Foster, R Condit, R Gupta, MP Soejarto, DD AF Calderon, AI Angerhofer, CK Pezzuto, JM Farnsworth, NR Foster, R Condit, R Gupta, MP Soejarto, DD TI Forest plot as a tool to demonstrate the pharmaceutical potential of plants in a tropical forest of Panama SO ECONOMIC BOTANY LA English DT Article DE Panama; plot-based plant selection; pharmaceutical potential; biological activity; bioassays; cancer chemoprevention; antiplasmodial; cytotoxicity; anti-HIV ID ORNITHINE DECARBOXYLASE ACTIVITY; LEUKEMIA-CELLS; SALMONELLA-TYPHIMURIUM; DIFFERENTIATION; 12-O-TETRADECANOYLPHORBOL-13-ACETATE; PROSTAGLANDINS; INHIBITORS; INDUCTION; INVITRO; HL-60 AB Based on literature analysis of 308 angiosperm species inventoried from a 50-hectare forest plot on Barro Colorado Island Panama, 40 species were selected and 80 samples (two samples for every species; leaf + twig and stembark samples) were collected for investigation of their medicinal/pharmaceutical potential. Extracts of these 80 samples were tested in bioassay systems to assess cancer chemoprevention (eight assays). antiplasmodial. cytotoxicity, and anti-HIV activities. Details of bioassay techniques are described Of the 40 species, 12 (30%) showed activity in one or more of the 11 bioassay systems used. These active species are Bombacopsis (= Pachira) quinata, Calophyllum longifolium. Casearia commersoniana, Lozania pittieri, Maclura tinctoria, Mouriri myrtilloides, Olmedia aspera (= Trophis caucana), Pseudobumbax septenatum, Spondias radlkoferi, Stylogyne standleyi, Turpinia occidentalis, and Vochysia ferruginea. Because literature data on the chemistry of Bombacopsis (= Pachira) quinata, Lozania Dittieri, Mouriri myrtilloides, Olmedia aspera (= Trophis caucana), Pseudobombax septenatum. and Stylogyne standleyi, are lacking, and similar data on the other six species are deficient, further fractionation and isolation work on these active species potentially may yield novel, biologically active structures. This study demonstrates that a plot-based selection of plant species for evaluation of their potential,medicinal/ pharmaceutical value has merit in achieving such a goal, and should be used in a program on plant drug discovery. C1 Univ Panama, Coll Pharm, Ctr Pharmacognost Res Panamanian Flora, CIFLORPAN, Panama City, Panama. Field Museum Nat Hist, Dept Bot, Environm Program, Chicago, IL 60612 USA. Field Museum Nat Hist, Dept Bot, Conservat Program, Chicago, IL 60612 USA. Smithsonian Trop Res Inst, Balboa, Panama. Univ Illinois, Coll Pharm, Program Collaborat Res Pharmaceut Sci, Chicago, IL 60612 USA. RP Calderon, AI (reprint author), Univ Panama, Coll Pharm, Ctr Pharmacognost Res Panamanian Flora, CIFLORPAN, Apartado 10767, Panama City, Panama. OI Gupta, Mahabir/0000-0002-9302-7864 NR 43 TC 16 Z9 18 U1 2 U2 7 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0013-0001 J9 ECON BOT JI Econ. Bot. PD JUL-SEP PY 2000 VL 54 IS 3 BP 278 EP 294 DI 10.1007/BF02864782 PG 17 WC Plant Sciences SC Plant Sciences GA 372LU UT WOS:000165235800007 ER PT J AU Rappole, JH Derrickson, SR Hubalek, Z AF Rappole, JH Derrickson, SR Hubalek, Z TI Migratory birds and spread of West Nile virus in the Western Hemisphere SO EMERGING INFECTIOUS DISEASES LA English DT Article ID MOSQUITOS AB West Nile virus, an Old World flavivirus related to St. Louis encephalitis virus, was first recorded in the New World during August 1999 in the borough of Queens, New York City. Through October 1999, 62 patients, 7 of whom died, had confirmed infections with the virus. Ornithophilic mosquitoes are the principal vectors of West Nile virus in the Old World, and birds of several species, chiefly migrants, appear to be the major introductory or amplifying hosts. If transovarial transmission or survival in overwintering mosquitoes were the principal means for its persistence, West Nile virus might not become established in the New World because of aggressive mosquito suppression campaigns conducted in the New York area. However, the pattern of outbreaks in southern Europe suggests that viremic migratory birds may also contribute to movement of the virus. If so, West Nile virus has the potential to cause outbreaks throughout both temperate and tropical regions of the Western Hemisphere. C1 Smithsonian Inst, Conservat & Res Ctr, Front Royal, VA USA. Acad Sci Czech Republ, Inst Vertebrate Biol, Valtice, Czech Republic. RP Rappole, JH (reprint author), 1500 Remount Rd, Front Royal, VA 22630 USA. RI Hubalek, Zdenek/G-1111-2014 OI Hubalek, Zdenek/0000-0003-4732-0987 NR 48 TC 292 Z9 319 U1 6 U2 29 PU CENTER DISEASE CONTROL PI ATLANTA PA ATLANTA, GA 30333 USA SN 1080-6040 J9 EMERG INFECT DIS JI Emerg. Infect. Dis PD JUL-AUG PY 2000 VL 6 IS 4 BP 319 EP 328 PG 10 WC Immunology; Infectious Diseases SC Immunology; Infectious Diseases GA 342TH UT WOS:000088660900001 PM 10905964 ER PT J AU McNeill, DF Coates, AG Budd, AF Borne, PF AF McNeill, DF Coates, AG Budd, AF Borne, PF TI Integrated paleontologic and paleomagnetic stratigraphy of the upper Neogene deposits around Limon, Costa Rica: A coastal emergence record of the Central American Isthmus SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article DE chronostratigraphy; corals; Costa Rica; Limon; Pliocene; sea level ID COCOS-RIDGE; ARC RESPONSE; SEA-LEVEL; PANAMA; SUBDUCTION; PLIOCENE; PACIFIC; HISTORY; BASIN; ENVIRONMENTS AB A chronostratigraphic study of mixed carbonate and siliciclastic sediments (Limon Group) along the Caribbean side of the Central American Isthmus was conducted to provide refined depositional ages on the uplifted, nearshore marine sequence exposed near Limon, Costa Rica, These upper Neogene sediments provide a rich faunal history that spanned the closure of the isthmus and cessation of marine circulation between the Pacific Ocean and Caribbean Sea. This faunal archive provides a critical link in regional assessment of evolutionary changes that resulted from the development of the Central American Isthmus, Results from this study have shown that integrated biostratigraphic and magnetostrati-graphic techniques can be successfully combined to provide refined age dating in shallow-marine sediments, even where some microfossil reworking has occurred. We propose the new Quebrada Chocolate Formation to represent latest early-early late Pliocene mixed reefal and siliciclastic deposits that overlie the early Pliocene Rio Banano Formation, The superjacent Moin Formation is expanded to include a second reefal interval deposited near the late Pliocene-Pleistocene boundary as well as fine-grained, mollusk-rich deposits in the forereef and lagoon. The style of mixed-system reef geometry between the two units is distinct, The Quebrada Chocolate Formation reefs consist of a lower interval of alternating reefal units buried by siliciclastic sediment and an upper unit comprised of stacked, reefal buildups with relatively minor siliciclastic matrix, These stacked reefs formed on a rising sea level. In contrast, the Moin Formation reefs are isolated corals and patch reefs within a siliciclastic matrix that were deposited during the peak (maximum flooding) of the sea-level highstand, Our refined age model for the Limon Group sediments allows reassessment bf Pleistocene uplift rates. We calculate a rate of about 50 m/m.y., slightly less than previous rate estimates, attributed to the shallow i subduction in the Pacific of the Cocos Ridge beneath the Central American island-ate system. resolution Development of similar high-resolution models from other marine basins should provide the chronostratigraphic control necessary to assess environmental events and evolutionary trends in shallow-marine faunas separated and isolated by the Central American Isthmus. C1 Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Div Marine Geol & Geophys, Miami, FL 33149 USA. Smithsonian Trop Res Inst, Balboa, Panama. Univ Iowa, Dept Geol, Iowa City, IA 52242 USA. Louisiana State Univ, Louisiana Sea Grant Coll Program, Baton Rouge, LA 70803 USA. RP McNeill, DF (reprint author), Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Div Marine Geol & Geophys, 4600 Rickenbacker Causeway, Miami, FL 33149 USA. NR 57 TC 35 Z9 39 U1 0 U2 4 PU ASSOC ENGINEERING GEOLOGISTS GEOLOGICAL SOCIETY AMER PI COLLEGE STN PA TEXAS A & M UNIV, DEPT GEOLOGY & GEOPHYSICS, COLLEGE STN, TX 77843-3115 USA SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD JUL PY 2000 VL 112 IS 7 BP 963 EP 981 DI 10.1130/0016-7606(2000)112<0963:IPAPSO>2.3.CO;2 PG 19 WC Geosciences, Multidisciplinary SC Geology GA 327YM UT WOS:000087822100001 ER PT J AU Tobisch, OT Fiske, RS Saleeby, JB Holt, E Sorensen, SS AF Tobisch, OT Fiske, RS Saleeby, JB Holt, E Sorensen, SS TI Steep tilting of metavolcanic rocks by multiple mechanisms, central Sierra Nevada, California SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article DE batholith; structure; volcanogenic wall rocks ID RITTER RANGE PENDANT; CANYON SHEAR ZONE; MAGMATIC ARC; EASTERN CALIFORNIA; FOOTHILLS TERRANE; DEFORMATION; EMPLACEMENT; BATHOLITH; TECTONICS; BELTS AB For similar to 200 km along the eastern Sierra Nevada continental magmatic are, Mesozoic metavolcanogenic rocks dip steeply to the southwest (similar to 80 degrees), a feature that must reflect fundamental processes in magmatic-arc construction, Although tight folds ran account for such steep bedding tilts, folds in the metavolcanogenic sections are sparse and small scale. We propose that the high bedding tilts were produced by a combination of thrusting, down ward displacement, and ductile deformation of the beds, The last two processes accompanied emplacement of the Sierra Nevada batholith, The Ritter Range pendant lies within this similar to 200 km belt and provides a relatively lar ge and well exposed Mesozoic volcanic section ranging in age from I,ate Triassic to mid-Cretaceous, Detailed mapping and ages from U-Pb zircon dates and fossils within the volcanic section reveal five structural blocks (I-V) that are separated by bedding-parallel thrusts, sonic of which are cryptic. To explain the present difference in bedding orientations between blocks III and IV,vp suggest that the thrusting may have had a duplex geometry, which produced a maximum bedding dip of similar to 45 degrees in sonic blocks. Downward displacement of wall rock and ductile strain account for the remaining similar to 35 degrees of the observed average bedding dip (similar to 80 degrees SW). The exact time of thrusting and duplex formation of I,ate Triassic to Early Jurassic rocks in blocks I-IV is uncertain, but these structures developed either (1) between P05 and 164 Ma, well before the other rotational processes were active, or (2) mostly around 105 Rla, and closer to the time when other rotational processes were active. Much of:the subsequent (ca, 91-76 Ma) bedding tilting is related to downward displacement of beds associated with the emplacement of voluminous I,ate Cretaceous plutons, and to regional duc tile deformation of the wall rocks during that period: the majority of the tilting probably took place between ca, 91 and 86 Ma. Bedding tilts of early to mid-Cretaceous rocks in blocks IV and V is bracketed between ca, 98 land ra, 90 Ma, Comparisons with metavolcanic sections to the northwest near Tioga Pass and to;the southeast in the Mount Morrison, Mount Goddard and Oak Creek pendants, suggest that bedding rotation by thrusting(?), downward displacement and ductile strain of wall rock may explain the steep dips along this entire similar to 200 km segment of the continental iarc, Similar mechanisms may operate at mid-crustal levels in other continental arcs. C1 Univ Calif Santa Cruz, Dept Earth Sci, Santa Cruz, CA 95064 USA. Natl Museum Nat Hist, Smithsonian Inst, Dept Mineral Sci, Washington, DC 20560 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 94112 USA. RP Tobisch, OT (reprint author), Univ Calif Santa Cruz, Dept Earth Sci, A232 Earth & Marine Sci Bldg, Santa Cruz, CA 95064 USA. NR 73 TC 22 Z9 22 U1 0 U2 2 PU ASSOC ENGINEERING GEOLOGISTS GEOLOGICAL SOCIETY AMER PI COLLEGE STN PA TEXAS A & M UNIV, DEPT GEOLOGY & GEOPHYSICS, COLLEGE STN, TX 77843-3115 USA SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD JUL PY 2000 VL 112 IS 7 BP 1043 EP 1058 DI 10.1130/0016-7606(2000)112<1043:STOMRB>2.3.CO;2 PG 16 WC Geosciences, Multidisciplinary SC Geology GA 327YM UT WOS:000087822100006 ER PT J AU Wood, B AF Wood, B TI Investigating human evolutionary history SO JOURNAL OF ANATOMY LA English DT Article; Proceedings Paper CT Joint Meeting of the Anatomical-Society-of-Great-Britain-and-Ireland / Anatomical-Society-of-Southern-Africa / Nederlandse-Anatomen-Verenigin CY APR 15-17, 1998 CL ROLDUC, NETHERLANDS SP Anat Soc Great Britain & Ireland, Anat Soc So Africa, Nederlandse Anatomen Verenigin DE evolution; hominins; dentition; cladistics; imaging ID EARLY HOMINID PHYLOGENY; PLIO-PLEISTOCENE HOMINIDS; TRAIT LIST BIAS; DENTAL DEVELOPMENT; SEXUAL DIMORPHISM; COMPUTED-TOMOGRAPHY; AUSTRALOPITHECUS-AFRICANUS; CLADISTIC-ANALYSIS; SOUTH-AFRICA; INTRASPECIFIC VARIATION AB We rely on fossils for the interpretation of more than 95% of our evolutionary history. Fieldwork resulting in the recovery of fresh fossil evidence is an important component of reconstructing human evolutionary history, but advances can also be made by extracting additional evidence for the existing fossil record, and by improving the methods used to interpret the fossil evidence. This review shows how information from imaging and dental microstructure has contributed to improving our understanding of the hominin fossil record. It also surveys recent advances in the use of the fossil record for phylogenetic inference. C1 George Washington Univ, Washington, DC USA. Smithsonian Inst, Human Origins Program, Natl Museum Nat Hist, Washington, DC 20560 USA. RP Wood, B (reprint author), Dept Anthropol, 2110 G St NW, Washington, DC 20052 USA. NR 157 TC 6 Z9 7 U1 2 U2 8 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0021-8782 J9 J ANAT JI J. Anat. PD JUL PY 2000 VL 197 BP 3 EP 17 DI 10.1046/j.1469-7580.2000.19710003.x PN 1 PG 15 WC Anatomy & Morphology SC Anatomy & Morphology GA 353FK UT WOS:000089264000002 PM 10999269 ER PT J AU Wood, B Richmond, BG AF Wood, B Richmond, BG TI Human evolution: taxonomy and paleobiology SO JOURNAL OF ANATOMY LA English DT Article; Proceedings Paper CT Joint Meeting of the Anatomical-Society-of-Great-Britain-and-Ireland / Anatomical-Society-of-South-Africa / Nederlandse-Anatomen-Vereniging CY APR 15-17, 1998 CL ROLDUC, NETHERLANDS SP Anat Soc Great Britain & Ireland, Anat Soc So Africa, Nederlandse Anat Vereniging DE hominins; cladistics; Homo ID MODERN HUMAN ORIGINS; SIERRA-DE-ATAPUERCA; SINGLE-SPECIES HYPOTHESIS; STERKFONTEIN-MEMBER-2 FOOT BONES; LOWER PLEISTOCENE HOMINIDS; EARLY HOMO-CRANIA; AUSTRALOPITHECUS-AFARENSIS; SOUTH-AFRICA; SEXUAL DIMORPHISM; OLDUVAI-GORGE AB This review begins by setting out the context and the scope of human evolution. Several classes of evidence, morphological, molecular, and genetic, support a particularly close relationship between modern humans and the species within the genus Pan, the chimpanzee. Thus human evolution is the study of the lineage, or clade, comprising species more closely related to modern humans than to chimpanzees. Its stem species is the so-called 'common hominin ancestor', and its only extant member is Home sapiens. This clade contains all the species more closely-related to modern humans than to any other living primate. Until recently, these species were all subsumed into a family, Hominidae, but this group is now more usually recognised as a tribe, the Hominini. The rest of the review sets out the formal nomenclature, history of discovery, and information about the characteristic morphology, and its behavioural implications, of the species presently included in the human clade. The taxa are considered within their assigned genera, beginning with the most primitive and finishing with Home. Within genera, species are presented in order of geological age. The entries conclude with a list of the more important items of fossil evidence, and a summary of relevant taxonomic issues. C1 George Washington Univ, Dept Anthropol, Washington, DC 20052 USA. Smithsonian Inst, Human Origins Program, Natl Museum Nat Hist, Washington, DC 20560 USA. RP Wood, B (reprint author), George Washington Univ, Dept Anthropol, 2110 G St NW, Washington, DC 20052 USA. NR 397 TC 84 Z9 85 U1 17 U2 64 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0021-8782 EI 1469-7580 J9 J ANAT JI J. Anat. PD JUL PY 2000 VL 197 BP 19 EP 60 DI 10.1046/j.1469-7580.2000.19710019.x PN 1 PG 42 WC Anatomy & Morphology SC Anatomy & Morphology GA 353FK UT WOS:000089264000003 PM 10999270 ER PT J AU Jett, JA AF Jett, JA TI Recent literature on foraminifera SO JOURNAL OF FORAMINIFERAL RESEARCH LA English DT Bibliography C1 Smithsonian Inst, NMNH, Dept Palaeontol, Washington, DC 20560 USA. RP Jett, JA (reprint author), Smithsonian Inst, NMNH, Dept Palaeontol, MRC-121, Washington, DC 20560 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CUSHMAN FOUNDATION FORAMINIFERAL RES PI CAMBRIDGE PA MUSEUM COMPARATIVE ZOOLOGY, DEPT INVERTEBRATE PALEONTOLOGY 26 OXFORD ST, HARVARD UNIV, CAMBRIDGE, MA 02138 USA SN 0096-1191 J9 J FORAMIN RES JI J. Foraminifer. Res. PD JUL PY 2000 VL 30 IS 3 BP 246 EP 249 DI 10.2113/0300246 PG 4 WC Paleontology SC Paleontology GA 345HZ UT WOS:000088811700007 ER PT J AU Lu, H Fauchald, K AF Lu, H Fauchald, K TI A phylogenetic and biogeographic study of Euniphysa (Eunicidae, Polychaeta) SO JOURNAL OF NATURAL HISTORY LA English DT Article DE biogeography; coding; ecology; Euniphysa; Eunicidae; jaw; phylogeny; Polychaeta ID CLADISTIC-ANALYSIS AB Fourteen species have either been described in, or referred to, the genus Euniphysa. Seven of these are here re-described based on type material and two new species, E. quadridentata and E. filibranchia, are described. Euniphysa oculata is found to be a subjective synonym of E. spinea, and E. unicusa is a subjective synonym of E, aculeata. Euniphysa taiwanensis and E. megalodus are correctly assigned to the genus, but cannot be described due to lack of material. Euniphysa misakiensis, E. tubicola and E. tubifex are transferred to Eunice. A key is given to the nine identifiable species retained in Euniphysa. Coding strategies for polymorphic and inapplicable characters, as well as problems associated with shared absences, are discussed. A phylogenetic analysis of Euniphysa based on 24 morphological characters yielded two most parsimonious trees (CI = 0.902, RI = 0.905). The tree topology separates Euniphysa into two distinct groups. Group I includes E. filibranchia n. sp., E. italica, E. jeffreysii, E. quadridentata n, sp. and E. spinea, it is supported by five equivocal similarities. Group II is supported by five unequivocal synapomorphies and two equivocal similarities, it includes E. aculeata, E. auriculata, E. falciseta and E. tridontesa. Based on the phylogenetic topology, Paraeuniphysa and Heterophysa are considered as junior synonyms of Euniphysa. The recognition of a separate Family for Euniphysa is not warranted. All species of Euniphysa are fragile, shallow, warm water species. They have been collected mainly from sandy sediments of the Northern Hemisphere. The greatest diversity is from the South China Sea area; other species are found throughout the Indian Ocean, the Mediterranean Sea and the East Atlantic Ocean coasts suggesting the genus may have originated in the Tethys Sea. A few species have also been found in the Gulf of Mexico and the West Atlantic Ocean coast again suggesting a Tethyan origin associated with the westward drift of the North American continent. C1 George Washington Univ, Dept Biol Sci, Washington, DC 20052 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, Washington, DC 20560 USA. RP George Washington Univ, Dept Biol Sci, Washington, DC 20052 USA. EM hualu@gwu.edu NR 44 TC 9 Z9 10 U1 0 U2 3 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0022-2933 EI 1464-5262 J9 J NAT HIST JI J. Nat. Hist. PD JUL PY 2000 VL 34 IS 7 BP 997 EP 1044 DI 10.1080/00222930050020113 PG 48 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 325CE UT WOS:000087658100001 ER PT J AU Briceno, RD Eberhard, WG AF Briceno, RD Eberhard, WG TI Male wing positions during courtship by mediterranean fruit flies (Ceratitis capitata) (Diptera : tephritidae) SO JOURNAL OF THE KANSAS ENTOMOLOGICAL SOCIETY LA English DT Article AB Wing movements of courting male meddles, Ceratitis capitata, include previously undescribed twisting movements during continuous wing vibration, and continuous large amplitude dorsal-anteroventral movements during intermittent buzzing. The twisting movements may cause the sexually dimorphic rear portions of the male's wings to waft pheromone toward the female. C1 Univ Costa Rica, Escuela Biol, San Jose, Costa Rica. Univ Costa Rica, Smithsonian Trop Res Inst, San Jose, Costa Rica. RP Briceno, RD (reprint author), Univ Costa Rica, Escuela Biol, Ciudad Univ, San Jose, Costa Rica. NR 7 TC 3 Z9 3 U1 0 U2 0 PU KANSAS ENTOMOLOGICAL SOC PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 USA SN 0022-8567 J9 J KANSAS ENTOMOL SOC JI J. Kans. Entomol. Soc. PD JUL PY 2000 VL 73 IS 3 BP 143 EP 147 PG 5 WC Entomology SC Entomology GA 434UT UT WOS:000168834800002 ER PT J AU Falin, ZH Arneson, LC Wcislo, WT AF Falin, ZH Arneson, LC Wcislo, WT TI Night-flying sweat bees Megalopta genalis and Me. ecuadoria (Hymenoptera : Halictidae) as hosts of the parasitoid beetle Macrosiagon gracilis (Coleoptera : Rhipiphoridae) SO JOURNAL OF THE KANSAS ENTOMOLOGICAL SOCIETY LA English DT Article AB The nocturnal bees Megalopta genalis Meade-Waldo and Me. ecundoria Friese are reported as hosts of Macrosiagon gracilis Brewer, a member of a genus more commonly parasitic on solitary wasps. These associations represent the first halictid hosts for Macrosiagon as well as the first examples of a rhipiphorid parasitizing night-flying Hymenoptera. C1 KU Nat Hist Museum, Div Entomol, Snow Entomol Collect, Lawrence, KS 66045 USA. Smithsonian Trop Res Inst, Unit 0948, APO, AA 34002 USA. Smithsonian Trop Res Inst, Balboa, Ancon, Panama. RP Falin, ZH (reprint author), KU Nat Hist Museum, Div Entomol, Snow Entomol Collect, 1460 Jayhawk Blvd, Lawrence, KS 66045 USA. NR 6 TC 5 Z9 5 U1 1 U2 4 PU KANSAS ENTOMOLOGICAL SOC PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 USA SN 0022-8567 J9 J KANSAS ENTOMOL SOC JI J. Kans. Entomol. Soc. PD JUL PY 2000 VL 73 IS 3 BP 183 EP 185 PG 3 WC Entomology SC Entomology GA 434UT UT WOS:000168834800008 ER PT J AU Kalfatovic, MR AF Kalfatovic, MR TI Tales from the art crypt: The painters, the museums, the curators, the collectors, the auctions, the art. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst Lib, Washington, DC 20560 USA. RP Kalfatovic, MR (reprint author), Smithsonian Inst Lib, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD JUL PY 2000 VL 125 IS 12 BP 83 EP 83 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA 334UY UT WOS:000088205100065 ER PT J AU Kalfatovic, MR AF Kalfatovic, MR TI The Madonna of the future: Essays in a pluralistic art world. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst Lib, Washington, DC 20560 USA. RP Kalfatovic, MR (reprint author), Smithsonian Inst Lib, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD JUL PY 2000 VL 125 IS 12 BP 83 EP 83 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA 334UY UT WOS:000088205100063 ER PT J AU Riley, S AF Riley, S TI The confirmation. SO LIBRARY JOURNAL LA English DT Book Review C1 Smithsonian Inst Libs, Washington, DC USA. RP Riley, S (reprint author), Smithsonian Inst Libs, Washington, DC USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD JUL PY 2000 VL 125 IS 12 BP 141 EP 142 PG 2 WC Information Science & Library Science SC Information Science & Library Science GA 334UY UT WOS:000088205100377 ER PT J AU Wonham, MJ Carlton, JT Ruiz, GM Smith, LD AF Wonham, MJ Carlton, JT Ruiz, GM Smith, LD TI Fish and ships: relating dispersal frequency to success in biological invasions SO MARINE BIOLOGY LA English DT Article ID BALLAST WATER; SPECIES INTRODUCTIONS; MARINE ORGANISMS; GREAT-LAKES; RED-SEA; CONSEQUENCES; MECHANISMS; CALIFORNIA; TRANSPORT; ESTUARINE AB Most studies characterizing successful biological invaders emphasize those traits that help a species establish a new population. Invasions are, however, multi-phase processes with at least two phases, dispersal and introduction, that occur before establishment. Characteristics that enhance survival at any of these three phases will contribute to invasion success. Here, we synthesize information on the dispersal, introduction, and establishment of fishes mediated by ship ballast-water transport. We synthesize 54 reports of at least 31 fish species collected from ballast tanks (Phase 1), including 28 new reports from our recent studies (1986 to 1996), Our literature survey revealed 40 reports of 32 fish species whose introductions have been attributed to ballast transport (Phase 2), of which at least 24 survived to establish persistent populations (Phase 3). We detected little overlap at the species level between these two data sets (Phase 1 vs Phases 2 and 3), but patterns emerged at the family level, The Gobiidae (6 species), Clupeidae (4 species), and Gasterostcidae (1 species) were the most commonly found fish families in ballast tanks (Phase 1). The Gobiidae (13 species), Blenniidae (6 species) and Pleuronectidae (2 species) dominated the list of ballast-mediated introductions (Phase 2); gobies and blennies were the families most frequently established (Phase 3). The invasive success of gobies and blennies may be explained in part by their crevicolous nature: both groups seek refuge and lay eggs in small holes, and may take advantage of the ballast-intake holes on ship hulls. This behavior, not typically associated with invasive ability, may contribute to successful introduction and establishment by facilitating the dispersal phase of invasion. The failure of the pleuronectids to invade may reflect poor salinity match between donor and recipient regions. To develop a predictive framework of invasion success, organisms must be sampled at all three phases of the invasion process. Our comparison of two ballast sampling methods suggests that fishes have been undersampled in ballast-water studies, including our own, and that the role of ballast transport in promoting fish invasions has been underestimated. C1 Williams Coll, Mystic Seaport Maritime Studies Program, Mystic, CT 06355 USA. Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. Northeastern Univ, Ctr Marine Sci, Nahant, MA 01908 USA. RP Wonham, MJ (reprint author), Univ Washington, Dept Zool, Box 351800, Seattle, WA 98915 USA. OI Ruiz, Gregory/0000-0003-2499-441X NR 72 TC 126 Z9 141 U1 2 U2 51 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0025-3162 J9 MAR BIOL JI Mar. Biol. PD JUL PY 2000 VL 136 IS 6 BP 1111 EP 1121 DI 10.1007/s002270000303 PG 11 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 338ZH UT WOS:000088452800016 ER PT J AU Schnetzler, CC French, BM AF Schnetzler, CC French, BM TI Louis W. Walter (1933-2000) - Memorial SO METEORITICS & PLANETARY SCIENCE LA English DT Biographical-Item C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Mineral Sci, Washington, DC 20560 USA. RP Schnetzler, CC (reprint author), NASA, Goddard Space Flight Ctr, Mail Code 923, Greenbelt, MD 20771 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 2000 VL 35 IS 4 BP 881 EP 881 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 341YC UT WOS:000088617700027 ER PT J AU Bunch, LG AF Bunch, LG TI Flies in the buttermilk: Museums, diversity, and the will to change SO MUSEUM NEWS LA English DT Article C1 Smithsonian Inst, Washington, DC 20560 USA. RP Bunch, LG (reprint author), Smithsonian Inst, Washington, DC 20560 USA. NR 1 TC 2 Z9 2 U1 0 U2 0 PU AMER ASSOC MUSEUMS PI WASHINGTON PA 1575 EYE ST, NW, STE 400, WASHINGTON, DC 20005 USA SN 0027-4089 J9 MUSEUM NEWS JI Mus. News PD JUL-AUG PY 2000 VL 79 IS 4 BP 32 EP 35 PG 4 WC Art SC Art GA 333NB UT WOS:000088135200016 ER PT J AU Baptista, ARP Mathis, WN AF Baptista, ARP Mathis, WN TI Notes on the genus Cyamops Melander (Diptera : Periscelididae), including description of ten new species SO PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON LA English DT Article DE Diptera; Periscelididae; Cyampus; New World; Afrotropical; Australasian/Oceanian; Oriental; Palearctic AB The species of Cyamops Melander are reviewed for five regional faunas, including the description of 10 new species as follows: C. funkae (Guyana), C. nigeriensis (Nigeria), C. freidbergi (Madagascar), C. micronesicus (Yap), C. fiji (Fiji), C. samoensis (American Samoa), C. femoratus (Philippine Islands), C. laos (Laos), C. banvaneue (Laos), C. kaplanae (Thailand). Cyamops pectinatus Khoo is reported from Tasmania. Regional keys are provided for the New World, Afrotropical, Australasian/Oceanian, and Oriental faunas. C1 Smithsonian Inst, Museum Natl Hist Nat, Dept Entomol, Washington, DC 20560 USA. RP Baptista, ARP (reprint author), Smithsonian Inst, Museum Natl Hist Nat, Dept Entomol, Washington, DC 20560 USA. NR 11 TC 9 Z9 9 U1 0 U2 1 PU ENTOMOL SOC WASHINGTON PI WASHINGTON PA SMITHSONIAN INSTITUTION DEPT ENTOMOLOGY, WASHINGTON, DC 20560 USA SN 0013-8797 J9 P ENTOMOL SOC WASH JI Proc. Entomol. Soc. Wash. PD JUL PY 2000 VL 102 IS 3 BP 481 EP 506 PG 26 WC Entomology SC Entomology GA 335UY UT WOS:000088264200001 ER PT J AU Foster, GA Mathis, WN AF Foster, GA Mathis, WN TI Notes on neotropical species of Tethina Haliday (Diptera : Tethinidae) SO PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON LA English DT Article DE Diptera; Tethinidae; Tethina; neotropics AB Neotropical beach-fly species (Diptera: Tethinidae) not included in a previous faunal revision of the Caribbean, Gulf of Mexico, and Bermuda are reviewed, including description of the following new species (type locality in parenthesis): Tethina robusta (Chile. Osorno: Puchatrihue). Two new synonyms are also proposed (Junior synonyms cited first): Rhicnoessa sonorensis Melander = Tethina albula Loew and Tethina setulosa Malloch = Tethina spinulosa Cole. A revised key to the Neotropical species of Tethina and a diagnosis for the senior synonyms are provided. C1 Smithsonian Inst, Museum Natl Hist Nat, Dept Entomol, Washington, DC 20560 USA. RP Foster, GA (reprint author), Smithsonian Inst, Museum Natl Hist Nat, Dept Entomol, Washington, DC 20560 USA. NR 19 TC 4 Z9 4 U1 0 U2 0 PU ENTOMOL SOC WASHINGTON PI WASHINGTON PA SMITHSONIAN INSTITUTION DEPT ENTOMOLOGY, WASHINGTON, DC 20560 USA SN 0013-8797 J9 P ENTOMOL SOC WASH JI Proc. Entomol. Soc. Wash. PD JUL PY 2000 VL 102 IS 3 BP 542 EP 548 PG 7 WC Entomology SC Entomology GA 335UY UT WOS:000088264200005 ER PT J AU Gaimari, SD Irwin, ME AF Gaimari, SD Irwin, ME TI Revision of the Mexicana-group of the cycloteline genus Ozodiceromyia Bigot (Diptera : Therevidae) SO PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON LA English DT Article DE phylogeny; revision; morphology; cladistics ID PARSIMONY; OUTGROUPS AB The mexicana-group of the cycloteline genus Ozodiceromyia Bigot (Diptera: Therevidae) is treated. The two previously described species of the group, Ozodiceromyia mexicana Bigot (the type species) and Ozodiceromyia argentifera (Krober), are redescribed, and two new species, Ozodiceromyia livdahli and Ozodiceromyia parargentifera, are described. In addition, a neotype is designated for Phycus argentifer Krober, and a lectotype is designated for Euphycus setosus Krober, a junior subjective synonym of Ozodiceromyia mexicana. A phylogenetic hypothesis is discussed for the relationships among these taxa, characters and their evolution are discussed, a key to species is provided, and each species is diagnosed. C1 Univ Illinois, Urbana, IL 61801 USA. RP Gaimari, SD (reprint author), Smithsonian Inst, Dept Entomol, NHB 169, Washington, DC 20560 USA. NR 39 TC 5 Z9 5 U1 0 U2 0 PU ENTOMOL SOC WASHINGTON PI WASHINGTON PA SMITHSONIAN INSTITUTION DEPT ENTOMOLOGY, WASHINGTON, DC 20560 USA SN 0013-8797 J9 P ENTOMOL SOC WASH JI Proc. Entomol. Soc. Wash. PD JUL PY 2000 VL 102 IS 3 BP 561 EP 600 PG 40 WC Entomology SC Entomology GA 335UY UT WOS:000088264200007 ER PT J AU Mathis, WN Edmiston, JF AF Mathis, WN Edmiston, JF TI A revision of the shore-fly genus Lemnaphila Cresson (Diptera : Ephydridae) SO PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON LA English DT Article DE revision; Diptera; Ephydridae; shore flies; Lemnaphila; L. longicera; L. grossoae; New World AB Species of the shore-fly genus Lemnaphila Cresson are revised, including the description of two new species: L. grossoae (Argentina. Tucuman: San Miguel de Tucuman) and L. longicera (Peru. Loreto: Iquitos). Lemnaphila is known thus far only from the New World, where there are now five species. All species with known biologies are miners in various species of Lemnaceae. Although Lemnaphila is clearly a monophyletic clade based on several synapomorphies, its relationship to other genera of the tribe Hydrelliini is unresolved. C1 Smithsonian Inst, Dept Entomol, Natl Museum Nat Hist, Washington, DC 20560 USA. RP Mathis, WN (reprint author), Smithsonian Inst, Dept Entomol, Natl Museum Nat Hist, NHB 169, Washington, DC 20560 USA. NR 38 TC 2 Z9 4 U1 0 U2 0 PU ENTOMOL SOC WASHINGTON PI WASHINGTON PA SMITHSONIAN INSTITUTION DEPT ENTOMOLOGY, WASHINGTON, DC 20560 USA SN 0013-8797 J9 P ENTOMOL SOC WASH JI Proc. Entomol. Soc. Wash. PD JUL PY 2000 VL 102 IS 3 BP 652 EP 677 PG 26 WC Entomology SC Entomology GA 335UY UT WOS:000088264200014 ER PT J AU Steiner, WE Kingsolver, JM Arnett, RH AF Steiner, WE Kingsolver, JM Arnett, RH TI A tribute to Ted Spilman - Obituary SO PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON LA English DT Article C1 Smithsonian Inst, Dept Entomol, Washington, DC 20560 USA. RP Steiner, WE (reprint author), Smithsonian Inst, Dept Entomol, NHB-187, Washington, DC 20560 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ENTOMOL SOC WASHINGTON PI WASHINGTON PA SMITHSONIAN INSTITUTION DEPT ENTOMOLOGY, WASHINGTON, DC 20560 USA SN 0013-8797 J9 P ENTOMOL SOC WASH JI Proc. Entomol. Soc. Wash. PD JUL PY 2000 VL 102 IS 3 BP 761 EP 767 PG 7 WC Entomology SC Entomology GA 335UY UT WOS:000088264200022 ER PT J AU Gibson, TG Bybell, LM Mason, DB AF Gibson, TG Bybell, LM Mason, DB TI Stratigraphic and climatic implications of clay mineral changes around the Paleocene/Eocene boundary of the northeastern US margin SO SEDIMENTARY GEOLOGY LA English DT Article; Proceedings Paper CT Annual Meeting of the Geological-Society-of-America CY OCT 26-29, 1998 CL TORONTO, CANADA SP Geol Soc Amer DE kaolinite; Paleocene; Eocene ID BENTHIC FORAMINIFERAL EXTINCTION; EOCENE BOUNDARY; OCEANIC SEDIMENTS; COASTAL-PLAIN; BIGHORN BASIN; EVOLUTION; PALEOGENE; RECORDS; EVENTS; MARINE AB Kaolinite usually is present in relatively small amounts in most upper Paleocene and lower Eocene neritic deposits of the northern US Atlantic Coastal Plain. However, there is a short period (less than 200,000 k.y.) in the latest Paleocene (upper part of calcareous nannoplankton Zone NP 9) when kaolinite-dominated clay mineral suites replaced the usual illite/smectite-dominated suites. During this time of global biotic and lithologic changes, kaolinite increased from less than 5% of the clay mineral suite to peak proportions of 50-60% of the suite and then returned to less than 5% in uppermost Paleocene/lowermost Eocene strata. This kaolinite pulse is present at numerous localities from southern Virginia to New Jersey. These sites represent both inner and middle neritic depositional environments and reflect input from several river drainage systems. Thus, it is inferred that kaolinite-rich source areas were widespread in the northeastern US during the latest Paleocene. Erosion of these source areas contributed the kaolinite that was transported and widely dispersed into shelf environments of the Salisbury embayment. The kaolinite increase, which occurred during a time of relatively high sea level, probably is the result of intensified weathering due to increased temperature and precipitation. The southern extent of the kaolinite pulse is uncertain in that uppermost Paleocene beds have not been identified in the southern Atlantic Coastal Plain. The late Paleocene kaolinite pulse that consists of an increase to peak kaolinite levels followed by a decrease can be used for detailed correlation between more upbasin and more downbasin sections in the Salisbury embayment. Correlations show that more upbasin Paleocene/ Eocene boundary sections are erosionally truncated. They have varying portions of the kaolinite increase and, if present at all, discontinuous portions of the subsequent kaolinite decrease. As these truncated sections are disconformably overlain by lower Eocene strata, rapid erosional removal of large parts of the most kaolinite-rich PIE boundary clay deposits occurred by early Eocene time. Erosion of the kaolinite-rich P/E boundary beds was enhanced during times of sea-level fall when kaolinite-rich sediments were redeposited to produce kaolinite spikes in basal beds of lower and middle Eocene sequences that have little or no kaolinite elsewhere in the sequence. In contrast, more downbasin sites document only the upper, decreasing part of the kaolinite pulse. The absence of strata documenting the earlier kaolinite increase is attributed to slow sedimentation (condensed interval) as a result of a significant sea level rise that ponded most sediments in shallower waters, combined with the probable subsequent erosional removal of these thin downbasin deposits by oceanic currents. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Smithsonian Inst, Museum Natl Hist Nat, Dept Paleobiol, Washington, DC 20560 USA. US Geol Survey, Natl Ctr 926, Reston, VA 20192 USA. RP Gibson, TG (reprint author), Smithsonian Inst, Museum Natl Hist Nat, Dept Paleobiol, Washington, DC 20560 USA. NR 93 TC 71 Z9 71 U1 1 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0037-0738 J9 SEDIMENT GEOL JI Sediment. Geol. PD JUL PY 2000 VL 134 IS 1-2 BP 65 EP 92 DI 10.1016/S0037-0738(00)00014-2 PG 28 WC Geology SC Geology GA 341YG UT WOS:000088618100007 ER PT J AU Molella, AP AF Molella, AP TI Crystal fire: The birth of the information age. SO TECHNOLOGY AND CULTURE LA English DT Book Review C1 Smithsonian Inst, Lemelson Ctr Study Invent & Innovat, Washington, DC 20560 USA. RP Molella, AP (reprint author), Smithsonian Inst, Lemelson Ctr Study Invent & Innovat, Washington, DC 20560 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU JOHNS HOPKINS UNIV PRESS PI BALTIMORE PA JOURNALS PUBLISHING DIVISION, 2715 NORTH CHARLES ST, BALTIMORE, MD 21218-4319 USA SN 0040-165X J9 TECHNOL CULT JI Technol. Cult. PD JUL PY 2000 VL 41 IS 3 BP 623 EP 625 PG 3 WC History & Philosophy Of Science SC History & Philosophy of Science GA 339UB UT WOS:000088495300038 ER PT J AU Banaszak, AT LaJeunesse, TC Trench, RK AF Banaszak, AT LaJeunesse, TC Trench, RK TI The synthesis of mycosporine-like amino acids (MAAs) by cultured, symbiotic dinoflagellates SO JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY LA English DT Article DE coral bleaching; mycosporine-like amino acids (MAAs); symbiotic dinoflagellates; Amphidinium; Gloedinium; Symbiodinium; ultraviolet radiation ID MICROALGAL-INVERTEBRATE SYMBIOSES; ULTRAVIOLET UV RADIATION; GREAT-BARRIER-REEF; ABSORBING COMPOUNDS; ELEVATED-TEMPERATURE; OXIDATIVE STRESS; ANTHOPLEURA-ELEGANTISSIMA; SHIKIMATE PATHWAY; ALGAL SYMBIONTS; CORAL AB We tested the hypothesis that there is a relation between phylotypes (phylogenetic types, as determined by restriction fragment length polymorphism (RFLP) and partial sequence analysis of the small subunit ribosomal RNA gene (SSUrDNA)) and the synthesis of mycosporine-like amino acids (MAAs) by symbiotic dinoflagellates under the influence of ultraviolet radiation (UV-B/A) and photosynthetically active radiation (PAR). We exposed 27 isolates of symbiotic dinoflagellates simultaneously to UV-B/A and PAR, and subsequently determined the MAAs present in cell extracts and in the media. The algae used included 24 isolates of Symbiodinium spp. originating from jellyfishes, sea anemones, zoanthids, scleractinians, octocorals, and bivalves, and three others in the genera Gymnodinium, Gloeodinium and Amphidinium from a jellyfish, an hydrocoral and a flatworm, respectively. In this study, all of the phylotype A Symbiodinium spp, synthesized up to three identified MAAs. None of the 11 cultured phylotypes B and C Symbiodinium spp. synthesized MAAs. The three non-Symbiodinium symbionts also synthesized up to three MAAs. The results support a conclusion that phylotype A Symbiodinium spp. have a high predilection for the synthesis of MAAs, while phylotypes B and C do not. Synthesis of MAAs by symbiotic dinoflagellates in culture does not appear to relate directly to depths or to the UV exposure regimes from which the consortia were collected. (C) 2000 Elsevier Science B.V. All rights reserved. C1 Univ Calif Santa Barbara, Dept Ecol Evolut & Marine Biol, Santa Barbara, CA 93106 USA. Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. RP Trench, RK (reprint author), Univ Calif Santa Barbara, Dept Ecol Evolut & Marine Biol, Santa Barbara, CA 93106 USA. EM trench@lifesci.lscf.ucsb.edu RI LaJeunesse, Todd/B-1720-2009 OI LaJeunesse, Todd/0000-0001-7607-9358 NR 58 TC 104 Z9 107 U1 4 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0981 EI 1879-1697 J9 J EXP MAR BIOL ECOL JI J. Exp. Mar. Biol. Ecol. PD JUN 28 PY 2000 VL 249 IS 2 BP 219 EP 233 PG 15 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 326UQ UT WOS:000087755600005 ER PT J AU Iafolla, V Nozzoli, S Lorenzini, EC Shapiro, II Milyukov, V AF Iafolla, V Nozzoli, S Lorenzini, EC Shapiro, II Milyukov, V TI Developments of the general relativity accuracy test (GReAT): a ground-based experiment to test the weak equivalence principle SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT International Symposium on Experimental Gravitation CY AUG 16-21, 1999 CL SAMARKAND, UZBEKISTAN AB Some future tests of the weak equivalence principle (WEP) with laboratory-size proof masses are likely to be conducted in freefall conditions in order to improve the test accuracy substantially. Some years ago the authors of this paper proposed to test the WEP in a vertical freefall inside a capsule released from a high-altitude balloon. The estimated accuracy in testing the WEP, with a 95% confidence level, is a few parts in 10(15) in a 30 s freefall. When compared with other proposed orbital freefall experiments and ground-based tests, the vertical freefall retains some key advantages of the former without some of the disadvantages of the latter. Moreover, a two orders of magnitude increase in the accuracy of resting the WEP could be achieved with an affordable experiment that allows us to recover the detector and repeat the launches at short time intervals. C1 CNR, Ist Fis Spazio Interplanetario, I-00044 Frascati, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Moscow Univ, Sternberg Astron Inst, Moscow, Russia. RP Iafolla, V (reprint author), CNR, Ist Fis Spazio Interplanetario, I-00044 Frascati, Italy. OI Iafolla, Valerio Antonio/0000-0001-5297-1157 NR 3 TC 9 Z9 9 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0264-9381 J9 CLASSICAL QUANT GRAV JI Class. Quantum Gravity PD JUN 21 PY 2000 VL 17 IS 12 BP 2327 EP 2330 DI 10.1088/0264-9381/17/12/304 PG 4 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 335QG UT WOS:000088255200005 ER PT J AU Lehar, J Falco, EE Kochanek, CS McLeod, BA Munoz, JA Impey, CD Rix, HW Keeton, CR Peng, CY AF Lehar, J Falco, EE Kochanek, CS McLeod, BA Munoz, JA Impey, CD Rix, HW Keeton, CR Peng, CY TI Hubble Space Telescope observations of 10 two-image gravitational lenses SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : fundamental parameters; gravitational lensing ID RADIO-SOURCE PKS1830-211; DOUBLE QSO HE-1104-1805; EINSTEIN RING; TIME-DELAY; ELLIPTICAL GALAXIES; SPHERICAL GALAXIES; LENSING GALAXY; BINARY QUASAR; PKS 1830-211; REDSHIFT AB We report an a program to obtain Hubble Space Telescope (HST) observations of galaxy-mass gravitational lens systems at optical and infrared wavelengths. Here we discuss the properties of 10 two-image gravitational lens systems (Q0142 - 100 = UM 673, B0218 + 357, SBS 0909 + 532, BRI 0952 - 0115, LBQS 1009 - 0252, Q1017 - 207 = J03.13, B1030 + 074, HE 1104-1805, Q1208 + 1011, and PKS 1830 -211). We grouped these 10 systems because they have limited lens model constraints and often show poor contrast between the images and the lens galaxy. Of the 10 lens galaxies, seven are probably early-type galaxies, two are probably late-type galaxies (B0218 + 357 and PKS 1830 - 211), and one was not detected (01208 + 1011). We detect the host galaxies of the z(s) = 4.50 lensed quasar in BRI 0952 -0115, the z(s) = 2.32 lensed quasar in HE 1104 - 1805, and the unlensed z = 1.63 quasar near LBQS 1009 - 0252. We fit a set of four standard lens models to each lens that had sufficient constraints to compare isothermal dark matter and constant mass-to-light lens models, and to explore the effects of local tidal shears. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Max Planck Inst Astron, D-69117 Heidelberg, Germany. RP Lehar, J (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 97 TC 155 Z9 155 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2000 VL 536 IS 2 BP 584 EP 605 DI 10.1086/308963 PN 1 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335EQ UT WOS:000088230900008 ER PT J AU Narayan, R AF Narayan, R TI Hydrodynamic drag on a compact star orbiting a supermassive black hole SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion; accretion disks; black hole physics; galaxies : nuclei; gravitation; relativity ID ADVECTION-DOMINATED ACCRETION; SAGITTARIUS-A-ASTERISK; GRAVITATIONAL-WAVES; MULTIPOLE MOMENTS; FLOWS; GALAXIES; MODEL; QUIESCENCE; SPECTRUM; DISKS AB The proposed Laser Interferometer Space Antenna is expected to detect gravitational waves from compact stars spiraling into supermassive black holes in distant galactic nuclei. Analysis of the inspiral events will require careful comparison of the observed signals with theoretical waveform templates. The comparison could be seriously compromised if nongravitational torques modify the orbit of the star. This paper estimates the torque exerted on an orbiting star as a result of hydrodynamic interactions with an accretion how around the supermassive black hole. It is argued that the majority of inspiral events will take place in low-luminosity galactic nuclei in which the mass accretion rate is low and the accretion occurs via an advection-dominated flow. The hydrodynamic torque is negligibly small in such systems and will have no effect on gravitational wave experiments. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Narayan, R (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 50 TC 46 Z9 46 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2000 VL 536 IS 2 BP 663 EP 667 DI 10.1086/308956 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335EQ UT WOS:000088230900012 ER PT J AU Nicastro, F Piro, L De Rosa, A Feroci, M Grandi, P Fiore, F Elvis, M Haardt, F Kaastra, J Malizia, A Maraschi, L Matt, G Perola, GC Petrucci, PO AF Nicastro, F Piro, L De Rosa, A Feroci, M Grandi, P Fiore, F Elvis, M Haardt, F Kaastra, J Malizia, A Maraschi, L Matt, G Perola, GC Petrucci, PO TI A long observation of NGC 5548 by BeppoSAX: The high-energy cutoff, intrinsic spectral variability, and a truly warm absorber SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (NGC 5548); galaxies : Seyfert; radiation mechanisms : thermal; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; BROAD-LINE REGION; NGC-5548; ABSORPTION; GEOMETRY; PHOTOIONIZATION AB NGC 5548 was observed by BeppoSAX in a single long (8 day) observation from 0.2 to 200 keV. We find (1) spectral variation of the source produced by a change of the intrinsic power-law slope; (2) a high-energy cutoff at E-c = 115(-27)(+39) keV with a hint of change of E-c with flux; and (3) O VII and O VIII absorption K edges and a possible blended O VII-O VIII K alpha,beta emission feature at 0.54(-0.06)(+0.07) keV, inconsistent with a purely photoionized gas in equilibrium. We propose that the temperature of the absorbing and emitting gas is similar to 10(6) K so that both collisional ionization and photoionization contribute. C1 CNR, Ist Astrofis Spaziale, I-00133 Rome, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Osservatorio Astron Roma, I-00040 Monte Porzio Catone, Italy. Univ Milan, Dipartimento Fis, Milan, Italy. Space Res Org Netherlands, NL-3584 CA Utrecht, Netherlands. BeppoSAX Sci Data Ctr, Rome, Italy. Osservatorio Astron Brera Merate, Milan, Italy. Univ Roma 3, Dipartimento Fis, I-00146 Rome, Italy. RP Nicastro, F (reprint author), CNR, Ist Astrofis Spaziale, Via Fosso del Cavaliere, I-00133 Rome, Italy. RI PIRO, LUIGI/E-4954-2013; OI PIRO, LUIGI/0000-0003-4159-3984; Nicastro, Fabrizio/0000-0002-6896-1364; Feroci, Marco/0000-0002-7617-3421; De Rosa, Alessandra/0000-0001-5668-6863; Fiore, Fabrizio/0000-0002-4031-4157 NR 39 TC 40 Z9 40 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2000 VL 536 IS 2 BP 718 EP 728 DI 10.1086/308950 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335EQ UT WOS:000088230900017 ER PT J AU Campbell, MF Garland, CA Deutsch, LK Hora, JL Fazio, GG Dayal, A Hoffmann, WF AF Campbell, MF Garland, CA Deutsch, LK Hora, JL Fazio, GG Dayal, A Hoffmann, WF TI Narrowband mid-infrared images and models of the HII complex G34.3+0.2 SO ASTROPHYSICAL JOURNAL LA English DT Article DE HII regions; infrared : general; ISM : individual (G34.3+0.2); stars : formation ID H-II-REGIONS; MOLECULAR CLOUD; AMMONIA OBSERVATIONS; PHYSICAL-PROPERTIES; LINE OBSERVATIONS; DUST; STARS; CORE; RECOMBINATION; ENVIRONMENTS AB We present mid-infrared images of the ultracompact H II region complex G34.3+0.2 taken on the IRTF through a 1.8% circular variable filter wheel at 8.0, 9.7, 11.2, 12.8, and 13.2 mu m and through a 6.8% filter at 20.6 mu m. Infrared emission was detected at the radio components A, C (the "cometary" component), and D. In addition, two new sources of emission were found south of C at 20.6 pm; we assign them names of E and F. Infrared emission was not detected at B, and C does not have the famous cometary shape that is observed in radio continuum emission. Photometric flux densities and source sizes are determined for A, C, and E. Radiative transfer models are then presented to match the observed dust emission for these sources. Based on the observations and models, an overview of the complex is suggested in which C is an approximately spherical centrally heated source that was not formed from material in the adjacent ultracompact molecular core. C is not a blister source, and it is not colliding with the molecular core. C1 Colby Coll, Dept Phys & Astron, Waterville, ME 04901 USA. Boston Univ, Dept Astron, Boston, MA 02215 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, IPAC, Pasadena, CA 91125 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. RP Colby Coll, Dept Phys & Astron, Waterville, ME 04901 USA. EM mfcampbe@colby.edu; garland@polaris.astro.ufl.edu; deutschl@bu.edu; jhora@cfa.harvard.edu; fazio@cfa.harvard.edu; adayal@ipac.caltech.edu; hoffmann@as.arizona.edu OI Hora, Joseph/0000-0002-5599-4650 NR 57 TC 18 Z9 18 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2000 VL 536 IS 2 BP 816 EP 830 DI 10.1086/308970 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335EQ UT WOS:000088230900025 ER PT J AU Seward, FD Alpar, MA Flanagan, C Kiziloglu, U Markwardt, C McCulloch, P Ogelman, H AF Seward, FD Alpar, MA Flanagan, C Kiziloglu, U Markwardt, C McCulloch, P Ogelman, H TI ROSAT observations of the Vela pulsar SO ASTROPHYSICAL JOURNAL LA English DT Article DE pulsars : individual (Vela pulsar); stars : neutron; X-rays : stars ID X-RAY-EMISSION; NEUTRON-STAR; THERMAL RESPONSE; MATTER; EQUATION; GLITCHES AB The ROSAT HRI was used to monitor X-ray emission from the Vela pulsar. Six observations span 2.5 yr and three glitches. The summed data yield a determination of the pulse shape, and X-ray emission from the pulsar is found to be 12% pulsed with one broad and two narrow peaks. One observation occurred 15 days after a large glitch. No change in pulse structure was observed, and any change in X-ray luminosity, if present, was less than 3%. Implications for neutron star structure are discussed. C1 Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. Sabanci Univ, TR-81474 Istanbul, Turkey. Hartebeesthoek Radio Observ, ZA-1740 Krugersdorp, Transvaal, South Africa. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Tasmania, Sch Phys, Hobart, Tas, Australia. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. RP Seward, FD (reprint author), Smithsonian Astrophys Observ, 60 Garden St, Cambridge, MA 02138 USA. NR 28 TC 8 Z9 8 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2000 VL 536 IS 2 BP 948 EP 953 DI 10.1086/308961 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335EQ UT WOS:000088230900038 ER PT J AU Griesmann, U Kling, R AF Griesmann, U Kling, R TI Interferometric measurement of resonance transition wavelengths in CIV, SiIV, AlIII, AlII, and SiII SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic data; methods : laboratory; techniques : spectroscopic ID SPACE-TIME VARIATION; VACUUM-ULTRAVIOLET; FE-I; C-IV; ATOMS; CONSTANTS; DISCHARGE; SPECTRUM AB We have made the first interferomeric measurements of the wavelengths of the important ultraviolet diagnostic lines in the spectra C Iv near 155 nm and Si Iv near 139 nm with a vacuum ultraviolet Fourier transform spectrometer and high-current discharge sources. The wavelength uncertainties were reduced by 1 order of magnitude for the C Iv lines and by 2 orders of magnitude for the Si Iv lines. Our measurements also provide accurate wavelengths for resonance transitions in Al III, Al II, and Si II. C1 NIST, Gaithersburg, MD 20899 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Griesmann, U (reprint author), NIST, Gaithersburg, MD 20899 USA. NR 21 TC 27 Z9 27 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2000 VL 536 IS 2 BP L113 EP L115 DI 10.1086/312741 PN 2 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335ER UT WOS:000088231000014 ER PT J AU Warren, HP AF Warren, HP TI Fine structure in solar flares SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : corona; Sun : flares ID X-RAY TELESCOPE; TRANSITION REGION; CORONAL EXPLORER; YOHKOH; RECONNECTION; MORPHOLOGY; PLASMA; VIEW AB We present observations of several large two-ribbon flares observed with both the Transition Region and Coronal Explorer (TRACE) and the soft X-ray telescope on Yohkoh. The high spatial resolution TRACE observations show that solar flare plasma is generally not confined to a single loop or even a few isolated loops but to a multitude of fine coronal structures. These observations also suggest that the high-temperature flare plasma generally appears diffuse while the cooler (less than or similar to 2 MK) postflare plasma is looplike. We conjecture that the diffuse appearance of the high-temperature flare emission seen with TRACE is due to a combination of the emission measure structure of these flares and the instrumental temperature response and does not reflect fundamental differences in plasma morphology at the different temperatures. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Warren, HP (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St,MS 58, Cambridge, MA 02138 USA. NR 16 TC 24 Z9 24 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2000 VL 536 IS 2 BP L105 EP L108 DI 10.1086/312734 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335ER UT WOS:000088231000012 ER PT J AU Weisskopf, MC Hester, JJ Tennant, AF Elsner, RF Schulz, NS Marshall, HL Karovska, M Nichols, JS Swartz, DA Kolodziejczak, JJ O'Dell, SL AF Weisskopf, MC Hester, JJ Tennant, AF Elsner, RF Schulz, NS Marshall, HL Karovska, M Nichols, JS Swartz, DA Kolodziejczak, JJ O'Dell, SL TI Discovery of spatial and spectral structure in the X-ray emission from the Crab Nebula SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (Crab Nebula); pulsars : individual (Crab Pulsar); radiation mechanisms : nonthermal; stars : neutron; supernova remnants; X-rays : general ID PULSAR WINDS; POLARIZATION; MODEL AB The Chandra X-Ray Observatory observed the Crab Nebula and pulsar during orbital calibration. Zeroth-order images with the High-Energy Transmission Grating (HETG) readout by the Advanced CCD Imaging Spectrometer spectroscopy array (ACIS-S) show a striking richness of X-ray structure at a resolution comparable to that of the best ground-based visible-light observations. The HETG-ACIS-S images reveal, for the first time, an X-ray inner ring within the X-ray torus, the suggestion of a hollow-tube structure for the torus, and X-ray knots along the inner ring and (perhaps) along the inward extension of the X-ray jet. Although complicated by instrumental effects and the brightness of the Crab Nebula, the spectrometric analysis shows systematic variations of the Xray spectrum throughout the nebula. C1 NASA, Marshall Space Flight Ctr, Dept Space Sci, Huntsville, AL 35812 USA. Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Marshall Space Flight Ctr, Univ Space Res Assoc, Huntsville, AL 35812 USA. RP Weisskopf, MC (reprint author), NASA, Marshall Space Flight Ctr, Dept Space Sci, SD50, Huntsville, AL 35812 USA. NR 24 TC 260 Z9 262 U1 2 U2 5 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 2000 VL 536 IS 2 BP L81 EP L84 DI 10.1086/312733 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335ER UT WOS:000088231000006 ER PT J AU Ball, CD McCarthy, MC Thaddeus, P AF Ball, CD McCarthy, MC Thaddeus, P TI Cavity ringdown spectroscopy of the linear carbon chains HC7H, HC9H, HC11H, and HC13H SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ELECTRONIC ABSORPTION-SPECTRA; GAS-PHASE; NEON MATRICES; ANIONS; MOLECULES; RADICALS; (2)PI; C2NH; C10H AB Optical bands from the (3)Sigma(u)(-) <-- X (3)Sigma(g)(-) transition of the linear carbon chains HC7H, HC9H, HC11H, and HC13H have been measured in the gas phase by cavity ringdown spectroscopy. The bands exhibit well resolved P and R branches, which for HC7H are partially rotationally resolved. Comparisons between observed and simulated spectra indicate broadening in excess of that expected from the laser linewidth and Doppler width, suggesting rapid radiationless transitions in roughly 0.1-0.01 ns, a time scale consistent with the absence of observed fluorescence from these molecules. The HC7H and HC9H bands are of nearly equal strength, but those of the shorter chain HC5H are too weak to detect at the 1 ppm level. None of the bands observed here lies sufficiently close to any of the optical diffuse interstellar bands to provide positive identification. (C) 2000 American Institute of Physics. [S0021-9606(00)00423-2]. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. RP Ball, CD (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. OI McCarthy, Michael/0000-0001-9142-0008 NR 31 TC 39 Z9 40 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 15 PY 2000 VL 112 IS 23 BP 10149 EP 10155 DI 10.1063/1.481655 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 321XC UT WOS:000087479100011 ER PT J AU Riess, AG Filippenko, AV Liu, MC Challis, P Clocchiatti, A Diercks, A Garnavich, PM Hogan, CJ Jha, S Kirshner, RP Leibundgut, B Phillips, MM Reiss, D Schmidt, BP Schommer, RA Smith, RC Spyromilio, J Stubbs, C Suntzeff, NB Tonry, J Woudt, P Brunner, RJ Dey, A Gal, R Graham, J Larkin, J Odewahn, SC Oppenheimer, B AF Riess, AG Filippenko, AV Liu, MC Challis, P Clocchiatti, A Diercks, A Garnavich, PM Hogan, CJ Jha, S Kirshner, RP Leibundgut, B Phillips, MM Reiss, D Schmidt, BP Schommer, RA Smith, RC Spyromilio, J Stubbs, C Suntzeff, NB Tonry, J Woudt, P Brunner, RJ Dey, A Gal, R Graham, J Larkin, J Odewahn, SC Oppenheimer, B TI Tests of the accelerating universe with near-infrared observations of a high-redshift type Ia supernova SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; distance scale; supernovae : general ID LIGHT CURVES; STANDARD STARS; TIME DILATION; DUST; EXTINCTION; PHOTOMETRY; SPECTRA; EXPLOSION; CONSTANT; LAMBDA AB We have measured the rest-frame B-, V-, and I-band light curves of a high-redshift type Ia supernova (SN 1a), SN 1999Q (z = 0.46), using the Hubble Space Telescope (HST) and ground-based near-infrared detectors. A goal of this study is the measurement of the color excess, E(B-I), a sensitive indicator of interstellar or intergalactic dust, which could affect recent cosmological measurements from high-redshift SNe Ia. Our observations disfavor a 30% opacity of SN Ia visual light by dust as an alternative to an accelerating universe. This statement applies to both Galactic-type dust (rejected at the 3.4 sigma confidence level) and grayer dust (grain size > 0.1 mu m, rejected at the 2.3-2.6 sigma confidence level) as proposed by Aguirre. The rest-frame I-band light curve shows the secondary maximum 1 month after the B maximum typical of nearby SNe fa of normal luminosity, providing no indication of evolution as a function of redshift out to z approximate to 0.5. An expanded set of similar observations could improve the constraints on any contribution of extragalactic dust to the dimming of high-redshift SNe Ia. C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Santiago 22, Chile. Univ Washington, Dept Astron, Seattle, WA 98195 USA. European So Observ, D-8046 Garching, Germany. Cerro Tololo Interamer Observ, La Serena, Chile. Australian Natl Univ, Mt Stromlo & Siding Spring Observ, Weston, ACT 2611, Australia. Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. CALTECH 105 24, Dept Astron, Pasadena, CA 91125 USA. Natl Opt Astron Observ, Tucson, AZ 85719 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Riess, AG (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. RI Stubbs, Christopher/C-2829-2012; OI Stubbs, Christopher/0000-0003-0347-1724; Schmidt, Brian/0000-0001-6589-1287 NR 47 TC 121 Z9 123 U1 1 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 2000 VL 536 IS 1 BP 62 EP 67 DI 10.1086/308939 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 330LJ UT WOS:000087963300005 ER PT J AU Nevalainen, J Markevitch, M Forman, W AF Nevalainen, J Markevitch, M Forman, W TI X-ray total mass estimate for the nearby relaxed cluster A3571 SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; dark matter; galaxies : clusters : individual (A3571); intergalactic medium; X-rays : galaxies ID DARK-MATTER; SHAPLEY SUPERCLUSTER; PSPC OBSERVATIONS; GALAXY CLUSTERS; COOLING FLOWS; EMITTING GAS; ROSAT; PROFILES; A2256 AB We constrain the total mass distribution in the cluster A3571, combining spatially resolved ASCA temperature data with ROSAT imaging data with the assumption that the cluster is in hydrostatic equilibrium. The total mass within r(500) (1.7 h(50)(-1) Mpc) is M-500 = 7.8(-2.2)(+1.4) x 10(14) h(50)(-1) M-circle dot at 90% confidence, 1.1 times smaller than the isothermal estimate. The Navarro, Frenk, & White "universal profile" is a good description of the dark matter density distribution in A3571. The gas density profile is shallower than the dark matter profile, scaling as r(-2.1) at large radii, leading to a monotonically increasing gas mass fraction with radius. Within r(500) the gas mass fraction reaches a value of f(gas) = 0.19(-0.03)(+0.06) h(50)(-3/2) (90% confidence errors). Assuming that this value off,,, is a lower limit for the universal value of the baryon fraction, we estimate the 90% confidence upper limit of the cosmological matter density to be Omega(m) < 0.4. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Nevalainen, J (reprint author), Univ Helsinki, Helsinki, Finland. NR 38 TC 26 Z9 26 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 2000 VL 536 IS 1 BP 73 EP 78 DI 10.1086/308906 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 330LJ UT WOS:000087963300007 ER PT J AU Jayawardhana, R Holland, WS Greaves, JS Dent, WRF Marcy, GW Hartmann, LW Fazio, GG AF Jayawardhana, R Holland, WS Greaves, JS Dent, WRF Marcy, GW Hartmann, LW Fazio, GG TI Dust in the 55 Cancri planetary system SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; planetary systems; stars : individual (55 Cancri) ID EXTRASOLAR PLANETS; GIANT PLANETS; STARS; DISK; EVOLUTION; CLOUDS AB The presence of debris disks around similar to 1 Gyr old main-sequence stars suggests that an appreciable amount of dust may persist even in mature planetary systems. Here we report the detection of dust emission from 55 Cancri, a star with one, or possibly two, planetary companions detected through radial velocity measurements. Our observations at 850 and 450 mu m imply a dust mass of 0.0008-0.005 Earth masses, somewhat higher than that in the Kuiper Belt of our solar system. The estimated temperature of the dust grains and a simple model fit both indicate a central disk hole of at least 10 AU in radius. Thus, the region in which the planets are detected is likely to be significantly depleted of dust. Our results suggest that far-infrared and submillimeter observations are powerful tools for probing the outer regions of extrasolar planetary systems. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Joint Astron Ctr, Hilo, HI 96720 USA. Royal Observ, United Kingdom Astron Technol Ctr, Edinburgh EH9 3HJ, Midlothian, Scotland. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. RP Jayawardhana, R (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 24 TC 18 Z9 18 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 2000 VL 536 IS 1 BP 425 EP 428 DI 10.1086/308942 PN 1 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 330LJ UT WOS:000087963300037 ER PT J AU Uitenbroek, H AF Uitenbroek, H TI The CO fundamental vibration-rotation lines in the solar spectrum. II. Non-LTE transfer modeling in static and dynamic atmospheres SO ASTROPHYSICAL JOURNAL LA English DT Article DE line : formation; methods : numerical; radiative transfer; Sun : atmosphere; Sun : infrared; waves ID MULTILEVEL RADIATIVE-TRANSFER; LAMBDA ITERATION METHOD; CARBON-MONOXIDE; SPECTROMETER OBSERVATIONS; TRANSITION REGION; ENERGY-BALANCE; ACOUSTIC-WAVES; BANDS; SPECTROSCOPY; CHROMOSPHERE AB We present a numerical method for solving radiative transfer in molecular vibration-rotation bands that allows for departures from local thermodynamic equilibrium (LTE) while accurately including a large number of lines. The method is applied to the formation of the CO fundamental vibration-rotation bands in several plane-parallel hydrostatic models and in a sequence of 20 snapshots from a radiation-hydrodynamics simulation of chromospheric dynamics. Calculations for the hydrostatic models performed with different values of the collisional coupling between different vibrational states confirm earlier results in the literature showing that the CO lines have LTE source functions in the solar atmosphere, so emergent CO intensities reflect actual temperatures therein. Only if the canonical collisional strengths are too large by more than 2 orders of magnitude would it be possible to explain the low temperatures derived from CO line core intensities at the solar limb by scattering in an atmosphere with much higher temperatures, consistent with the values derived from UV line and continuum and Ca II resonance line diagnostics. An interesting feature in the wavelength structure of the CO vibration-rotation bands is pointed out, in which pairs of lines can be found in different bands but of similar strength and wavelength. In principle such pairs provide a diagnostic for departures from LTE in the CO lines. CO line core intensity variations computed from the sequence of dynamical snapshots, which represent a typical episode in the chromospheric dynamics simulation, have an amplitude that is 2.5 times higher than observed. It is shown that this large amplitude is due in part to the up and down shift of the CO line formation region during the evolution of the atmosphere and is related to the assumption of instantaneous chemical equilibrium that was assumed to calculate CO concentrations. This suggests that the CO concentration is not in equilibrium, may be lower than would be expected on the basis of chemical equilibrium at the time-averaged mean temperature of the atmosphere, and may have reduced variations compared to instantaneous chemical equilibrium values at the local temperatures. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Uitenbroek, H (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 37 TC 41 Z9 41 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 2000 VL 536 IS 1 BP 481 EP 493 DI 10.1086/308933 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 330LJ UT WOS:000087963300043 ER PT J AU Apponi, AJ McCarthy, MC Gottlieb, CA Thaddeus, P AF Apponi, AJ McCarthy, MC Gottlieb, CA Thaddeus, P TI The radio spectra of SiCCH, SiCN, and SiNC SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : molecules; line : identification; molecular data; molecular processes; radio lines : ISM ID PARAMETERS AB Three new silicon-bearing radicals of astrophysical interest, SiCCH and the two nearly isoenergetic isomers SiCN and SiNC, were detected in a laboratory discharge in their (XII)-I-2 ground states by Fourier transform microwave and millimeter-wave absorption spectroscopy. Hyperfine structure was observed in the low rotational transitions of the (II1/2)-I-2 ladder, and well-resolved Lambda-doubling was observed in both fine-structure ladders. With the spectroscopic constants derived from the laboratory measurements, the spectra of all three can be calculated to an uncertainty of less than 0.1 km s(-1) in equivalent radial velocity over the entire range of interest to radio astronomers. SiCN, with a dipole moment of 2.9 D, is probably the most promising of the three for astronomical discovery. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Apponi, AJ (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 16 TC 48 Z9 48 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 2000 VL 536 IS 1 BP L55 EP L58 DI 10.1086/312719 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 330LL UT WOS:000087963500014 ER PT J AU Concannon, KD Rose, JA Caldwell, N AF Concannon, KD Rose, JA Caldwell, N TI Spectral variations in early-type galaxies as a function of mass SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : abundances; galaxies : stellar content ID OLD STELLAR POPULATIONS; ELLIPTICAL GALAXIES; GLOBULAR-CLUSTERS; COMA CLUSTER; LUMINOSITY; EVOLUTION; ENRICHMENT; REDSHIFTS; INDEXES; MODEL AB We report on the strengths of three spectral indicators-Mg-2, H beta, and Hn/Fe-in the integrated light of a sample of 100 field and cluster E/SO galaxies. The measured indices are sensitive to age and/or metallicity variations within the galaxy sample. Using linear regression analysis for data with nonuniform errors, we determine the intrinsic scatter present among the spectral indices of our galaxy sample as a function of internal velocity dispersion. Our analysis demonstrates that there is significantly more intrinsic scatter in the two Balmer line indices than in the Mg, index, indicating that the Balmer indices provide more dynamic range in determining the age of a stellar population than does the Mg, index. Furthermore, the scatter is much larger for the low velocity dispersion galaxies, indicating that star formation has occurred more recently in the lower mass galaxies. C1 Univ N Carolina, Dept Phys & Astron, Chapel Hill, NC 27599 USA. Smithsonian Inst, FL Whipple Observ, Amado, AZ 85645 USA. RP Concannon, KD (reprint author), Univ N Carolina, Dept Phys & Astron, CB 3255, Chapel Hill, NC 27599 USA. NR 31 TC 17 Z9 17 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 2000 VL 536 IS 1 BP L19 EP L22 DI 10.1086/312727 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 330LL UT WOS:000087963500005 ER PT J AU Yin, QZ Jacobsen, SB McDonough, WF Horn, I Petaev, MI Zipfel, J AF Yin, QZ Jacobsen, SB McDonough, WF Horn, I Petaev, MI Zipfel, J TI Supernova sources and the (92)Nb-(92)Zr p-process chronometer SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; nuclear reactions, nucleosynthesis, abundances solar system : formation; supernovae : general ID GIANT BRANCH STARS; EARLY SOLAR-SYSTEM; ABUNDANCES; ELEMENTS; NUCLEI AB We report new Zr isotope evidence for live (92)Nb (mean life: <(tau)over bar>(92Nb) = 52 Myr) within the early solar system resulting in ((92)Nb/(93)Nb)(initial) approximate to 10(-3). The meteoritic minerals rutile and zircon have, respectively, very high and very low Nb/Zr ratios and are ideal for exploring the (92)Nb-(92)Zr chronometer. Rutiles exhibit high positive epsilon(92Zr) (similar to 14-36) while a zircon has a negative epsilon(92Zr) (similar to-4), as would be expected if 92Nb was live in the early solar system. The meteoritic rutiles appear to be young, with apparent times of formation of similar to 80-220 Myr subsequent to the origin of the solar system. The initial (92)Nb/(92)Mo for the solar system is broadly compatible with a model of uniform production if the 92Nb/92Mo production ratio for Type II supernova (SNII) sources with neutrino-driven winds is used. Data for all the now extinct p-process nuclides ((92)Nb, (97)Tc and (146)Sm) are consistent with these isotopes being derived by uniform production from SNII sources and a free decay interval of similar to 10 Myr. Consideration of a range of models indicates that the average p-process production ratio of 92Nb/92Mo needs to be at least in the range of 0.06-0.25. C1 Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Max Planck Inst Chem, Abt Kosmochem, D-55020 Mainz, Germany. RP Yin, QZ (reprint author), Harvard Univ, Dept Earth & Planetary Sci, 20 Oxford St, Cambridge, MA 02138 USA. EM yin@fas.harvard.edu; jacobsen@neodymium.harvard.edu RI Yin, Qing-Zhu/B-8198-2009; McDonough, William/C-4791-2009; Jacobsen, Stein/B-1759-2013; McDonough, William/I-7720-2012 OI Yin, Qing-Zhu/0000-0002-4445-5096; McDonough, William/0000-0001-9154-3673; McDonough, William/0000-0001-9154-3673 NR 26 TC 19 Z9 19 U1 0 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 2000 VL 536 IS 1 BP L49 EP L53 DI 10.1086/312718 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 330LL UT WOS:000087963500013 ER PT J AU Rocha, CEF Iliffe, TM Reid, JW Suarez-Morales, E AF Rocha, CEF Iliffe, TM Reid, JW Suarez-Morales, E TI Prehendocyclops, a new genus of the subfamily Halicyclopinae (Copepoda, Cyclopoida, Cyclopidae) from cenotes of the Yucatan Peninsula, Mexico SO SARSIA LA English DT Article DE Copepoda; Prehendocyclops; new genus; Caribbean Fauna; cenotes; Mexico AB Prehendocyclops, a new genus of Halicyclopinae, is described from cenotes of the Yucatan Peninsula, Mexico. Within the subfamily, the new genus resembles Halicyclops, Colpocyclops, and Smirnoviella in body shape as well as structure of the antennule and legs 1 to 5. In addition, Prehendocyclops shares with the latter two genera modifications in the antenna and mouth parts, which are here interpreted as structures used to hold onto some external part of a host. The possible host for the genus remains unknown. Prehendocyclops is characterized mainly in having an antennal prehensile device formed by a stout curved spine on the third segment, and the three proximalmost appendages of the terminal segment modified into stout, heavily serrate spines; the distalmost spine of these is claw-shaped. In addition, on the praecoxal arthrite of the maxillule the two outermost apical spines are curved towards a strong, straight, pointed spine inserted on the inner surface of the arthrite. The three species of Prehendocyclops described here (P. monchenkoi, P. boxshalli, and P abbreviatus) can be separated from each other by a combination of characters found in the integumental pore pattern of the body surface and legs 1-4, the number of tergal integumental windows, the shape of the seminal receptacle, and the armament of the caudal ramus, antenna, mouth parts, and legs 1, 4, and 5 of both sexes, as well as legs 5 and 6 of males. C1 Univ Sao Paulo, Inst Biociencias, Dept Zool, BR-05422970 Sao Paulo, Brazil. Texas A&M Univ, Dept Marine Biol, Galveston, TX 77553 USA. Natl Museum Nat Hist, Smithsonian Inst, Washington, DC 20560 USA. El Colegio Frontera Sur Chetumal, Quintana Roo 77000, Mexico. RP Rocha, CEF (reprint author), Univ Sao Paulo, Inst Biociencias, Dept Zool, CP 11461, BR-05422970 Sao Paulo, Brazil. NR 15 TC 6 Z9 7 U1 0 U2 0 PU UNIV BERGEN PI BERGEN PA DEPT FISHERIES/MAR. BIOLOGY BERGEN HIGH TECH CTR, N-5020 BERGEN, NORWAY SN 0036-4827 J9 SARSIA JI Sarsia PD JUN 9 PY 2000 VL 85 IS 2 BP 119 EP 140 PG 22 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 339YD UT WOS:000088504700002 ER PT J AU Yoshino, K Esmond, JR Parkinson, WH Thorne, AP Learner, RCM Cox, G Cheung, ASC AF Yoshino, K Esmond, JR Parkinson, WH Thorne, AP Learner, RCM Cox, G Cheung, ASC TI Fourier transform spectroscopy and cross section measurements of the Herzberg III bands of O-2 at 295 K SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID REGION 205-240 NM; MOLECULAR-OXYGEN; OSCILLATOR-STRENGTHS; HIGH-RESOLUTION; I BANDS; ABSORPTION; CONTINUUM; SYSTEM; PARAMETERS AB Fourier transform spectroscopic measurements of the absorption bands of the Herzberg III (A' (3)Delta(u)-X (3)Sigma(g)(-)) of O-2 at 295 K have been made with a resolution of 0.06 cm(-1) in the wavelength region 240 to 275 nm. Rotational line positions are determined with an accuracy of 0.005 cm(-1), and rotational term values are presented for the vibrational levels, v'=4-11. Precise band oscillator strengths of the (4,0)-(11,0) bands are obtained for the first time by direct measurement by summing the cross sections of individual rotational lines of the bands. The rotational line strengths and the branching ratios are also presented for the same bands. The continuity relationship for the band oscillator strengths to photodissociation continuum cross sections has been applied to the three-band systems. (C) 2000 American Institute of Physics. [S0021-9606(00)01221-6]. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BZ, England. Univ Hong Kong, Hong Kong, Hong Kong, Peoples R China. RP Yoshino, K (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. RI Cheung, Allan/D-3059-2009 NR 28 TC 12 Z9 13 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JUN 8 PY 2000 VL 112 IS 22 BP 9791 EP 9801 DI 10.1063/1.481702 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 319MV UT WOS:000087346500015 ER EF