Mandt, S. Atreya, A. Luspay-Kuti, O. Mousis, A. Simon and M. D. Hofstadter. Southwest Research Institute (6220 Culebra Rd., San Antonio, TX 78238 [email protected]), University of Texas at San Antonio (One UTSA Blvd, San Antonio, TX. University of Michigan, Ann Arbor, MI. Aix Marseille Université, CNRS, LAM (Laboratoire d'Astrophysique de Marseille) UMR 7326, 13388, Marseille, France. Goddard Spa...

We combine path-integral Monte Carlo methods with high-quality potential energy surfaces to compute equilibrium isotope effects in a variety of systems relevant to 'clumped' isotope analysis and isotope geochemistry, including CO2, N2O, methane, and propane. Through a systematic study of heavy-atom isotope-exchange reactions, we quantify and analyze errors that arise in the widely used Urey mod...

THERMAL IONIZATION MASS SPECTROMETRY STUDIES OF SM AND GD ISOTOPIC SHIFTS IN LUNAR METEORITES DUE TO NEUTRON CAPTURE: A PROGRESS REPORT. K. C. Welten, T. L. Owens, D. J. DePaolo, Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (e-mail: [email protected]); Center for Isotope Geochemistry, Department of Earth and Planetary Science, UC Berkeley & Lawrence Berkeley ...

We recently described a Bayesian framework for stable isotope mixing models and provided a software tool, MixSIR, for conducting such analyses (Ecol. Lett., 2008; 11:470). Jackson et al. (Ecol. Lett., 2009; 12:E1) criticized the performance of our software based on tests using simulated data. However, their simulation data were flawed, rendering claims of erroneous behaviour inaccurate. A re-ev...

The 1H and 13C NMR spectra of nosiheptide have been assigned by use of 2D NMR techniques on unlabeled samples and biosynthetically multiple-labeled samples from stable isotope feeding experiments.

Late Holocene climate in western North America was punctuated by periods of extended aridity called megadroughts. These droughts have been linked to cool eastern tropical Pacific sea surface temperatures (SSTs). Here, we show both short-term and long-term climate variability over the last 1,500 y from annual band thickness and stable isotope speleothem data. Several megadroughts are evident, in...

Fluxes of organic matter across habitat boundaries are common in food webs. These fluxes may strongly influence community dynamics, depending on the extent to which they are used by consumers. Yet understanding of basal resource use by consumers is limited, because describing trophic pathways in complex food webs is difficult. We quantified resource use for zooplankton, zoobenthos, and fishes i...

of Dissertation.............................................................................iii Acknowledgements..................................................................................vi Chapter One...........................................................................................1 A test of geographic assignment using isotope tracers in feathers of known origin Chapter Two......