22 research outputs found
BVRI Light Curves for 29 Type Ia Supernovae
BVRI light curves are presented for 27 Type Ia supernovae discovered during
the course of the Calan/Tololo Survey and for two other SNe Ia observed during
the same period. Estimates of the maximum light magnitudes in the B, V, and I
bands and the initial decline rate parameter m15(B) are also given.Comment: 17 pages, figures and tables are not included (contact first author
if needed), to appear in the Astronomical Journa
Osmocentrifugation In Density Gradients: Application To Polymer Latex Separation.
Polymer latexes can be fractionated by size and by chemical composition through osmocentrifugation. Density gradients are formed by centrifuging Ficoll and Percoll solutions in dialysis cells; mixed polymer latex zones are layered over these gradients and centrifuged again, leading to separated latex bands from which polymer may be collected and further analyzed. Zone migration rates in the osmocentrifugation experiment are faster than in standard centrifugation tubes.34285386
A taxonomic revision of the genus Weberbauerella Ulbr. (Leguminosae: Papilionoideae) in Peru and Chile.
The little-known and infrequently collected papilionoid legume genus is only known from outlying regions of the Atacama Desert. Presently it comprises three species, one in Chile and two in Peru. These small, woody, perennial species, enigmatic in both occurrence and form, are found growing in isolated populations in climatically extreme conditions. They are characterised by the presence of pustular glands throughout. Here we revise the genus, providing a key to the species, descriptions, distribution maps, illustrations, assessments of conservation status and notes on a northern variant population
Life and reproduction of titanosaurians: Isotopic hallmark of mid-palaeolatitude eggshells and its significance for body temperature, diet, and nesting
Eggshells represent an important part of the fossil record of Titanosauria (Dinosauria â Neosauropoda) and their stable isotope compositions are valuable palaeoenvironmental proxies. A new set of conventional (ÎŽ18O and ÎŽ13C) and clumped (Î47) stable isotope compositions of titanosaurian eggshells is presented, together with that of a bone and a single associated tooth, sampled in three Late Cretaceous nesting sites from La Rioja Province, NW Argentina. The preservation state of the fossils was first evaluated using optical and analytical techniques, such as transmitted light and optical cathodoluminescence (CL) microscopy, energy dispersive X-ray spectroscopy (EDX), and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). The isotopic compositions of the fossils were then compared to those of associated carbonate rocks and nodules, hydrothermal calcite and quartz, and those reported for eggshells from other nesting sites worldwide. This large, combined sample set allows us to define an isotopic hallmark (ÎŽ13CVPDB = â 15 to â 11â°; ÎŽ18OVSMOW = 27 to 33â°) typical for wellpreserved mid-palaeolatitude titanosaurian eggshells. This hallmark is intended to identify the oological specimens best suited for palaeoenvironmental reconstructions, for instance in museum collection samples that may lack associated abiogenic materials such as host rocks. In addition, our isotopic data support that titanosaurians were animals with an elevated body temperature, mainly feeding on C3 plants, and reproducing under conditions more arid than the long-term average. The data are in excellent agreement with the isotopic data reported from other mid-palaeolatitude nesting sites around the world, indicating that titanosaurians needed similar environmental conditions to reproduce, regardless of the palaeogeographic location of their habitat. Finally, we raise the question whether titanosaurians experienced reproduction-related fasting, as noted for several extant vertebrates, and discuss the complexity of interpreting Î47-derived temperatures, despite very consistent bulk isotopic data.Fil: Leuzinger, LĂ©a Sylvia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro Regional de Investigaciones CientĂficas y Transferencia TecnolĂłgica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones CientĂficas y Transferencia TecnolĂłgica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones CientĂficas y Transferencia TecnolĂłgica de La Rioja. - SecretarĂa de Industria y MinerĂa. Servicio GeolĂłgico Minero Argentino. Centro Regional de Investigaciones CientĂficas y Transferencia TecnolĂłgica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones CientĂficas y Transferencia TecnolĂłgica de La Rioja; ArgentinaFil: Bernasconi, Stefano Michele. Eidgenössische Technische Hochschule ZĂŒrich; SuizaFil: Vennemann, Torsten Walter. Universite de Lausanne; SuizaFil: Luz, Zoneibe. Universite de Lausanne; SuizaFil: Vonlanthen, Pierre. Universite de Lausanne; SuizaFil: Ulianov, Alexey. Universite de Lausanne; SuizaFil: Baumgartner Mora, Claudia. Universite de Lausanne; SuizaFil: Hechenleitner, Esteban MartĂn. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro Regional de Investigaciones CientĂficas y Transferencia TecnolĂłgica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones CientĂficas y Transferencia TecnolĂłgica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones CientĂficas y Transferencia TecnolĂłgica de La Rioja. - SecretarĂa de Industria y MinerĂa. Servicio GeolĂłgico Minero Argentino. Centro Regional de Investigaciones CientĂficas y Transferencia TecnolĂłgica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones CientĂficas y Transferencia TecnolĂłgica de La Rioja; ArgentinaFil: Fiorelli, Lucas Ernesto. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro Regional de Investigaciones CientĂficas y Transferencia TecnolĂłgica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones CientĂficas y Transferencia TecnolĂłgica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones CientĂficas y Transferencia TecnolĂłgica de La Rioja. - SecretarĂa de Industria y MinerĂa. Servicio GeolĂłgico Minero Argentino. Centro Regional de Investigaciones CientĂficas y Transferencia TecnolĂłgica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones CientĂficas y Transferencia TecnolĂłgica de La Rioja; ArgentinaFil: Alasino, Pablo Horacio. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Universidad Nacional de La Rioja; Argentin