.......................................................................................................................v RÉSUMÉ............................................................................................................................v INTRODUCTION...............................................................................................................1 Stable isotope chem...

The use of stable isotopes to solve biogeochemical problems in ecosystem analysis is increasing rapidly because stable isotope data can contribute both source-sink (tracer) and process information: The elements C, N, S, H, and all have more than one isotope, and isotopic compositions of natural materials can be measured with great precision with a mass spectrometer. Isotopic compositions change...

The measurement of naturally occurring glucocorticoids and stable isotopes of several elements has gained importance in wildlife studies in recent decades and opened a myriad of ecological applications. Cortisol and stable isotopes equilibrate in animal tissues over periods of integration related to the growth rate of the tissue, providing information reflecting systemic cortisol secretion and ...

The use of stable isotopes in studies of carotenoid biosynthesis is reviewed, beginning with early work with l8 which defined the origin of oxygen in a range of xanthophylls. A series of experiments from our own laboratory is then described, in which 2H and 13C have been used to investigate the stereochemistry of cyclization to form C40 and C50 and i-ring carotenoids. Novel procedures involving...

background: possibility to trace-label albumin with isotopes results in information concerning its synthesis, breakdown, and distribution in the intra and extra cellular spaces. the iodination of albumin is a widespread procedure used in scientific studies. bromine not only is more reactive and less expensive than iodine, but bonds more easily with many elements. therefore, it could be a suitab...

To document the evolution of the early cryosphere, stable isotope analyses were conducted on the planktonic and benthic foraminifers from Ocean Drilling Program Site 1218. We generated two parallel 54m-long records at 10-cm resolution and thus produced a standard Pacific stable isotope reference curve for the 26.4to 30.0-Ma interval within the Oligocene. These data are necessary to document the...

Systematic analysis of the deformations of proton and neutron densities in even-even C isotopes was done based on the method of antisymmetrized molecular dynamics. The E2 transition strength was discussed in relation to the deformation. We analyze the B(E2; 2 + 1 → 0 + 1) in 16 C, which has been recently measured to be abnormally small. The results suggest the difference of the deformations bet...

Divergent selection and adaptive divergence can increase phenotypic diversification amongst populations and lineages. Yet adaptive divergence between different environments, habitats or niches does not occur in all lineages. For example, the colonization of freshwater environments by ancestral marine species has triggered adaptive radiation and phenotypic diversification in some taxa but not in...