Intraspecific competition for food is expected to increase the trophic niche width of consumers, defined here as their diet diversity, but this process has been little studied in herbivores. Population densities of small rodents fluctuate greatly, providing a good study model to evaluate effects of competition on trophic niche. We studied resource use in five arctic small rodent populations of ...

The last interglacial interval was terminated by the inception of a long, progressive glaciation that is attributed to astronomically influenced changes in the seasonal distribution of sunlight over the earth. However, the feedbacks, internal dynamics, and global teleconnections associated with declining northern summer insolation remain incompletely understood. Here we show that a crucial earl...

Stable heavy isotopes co-exist with their lighter counterparts in all elements commonly found in biology. These heavy isotopes represent a low natural abundance in isotopic composition but impose great retardation effects in chemical reactions because of kinetic isotopic effects (KIEs). Previous isotope analyses have recorded pervasive enrichment or depletion of heavy isotopes in various organi...

Dietary adaptations of prehistoric hunter-gatherers from Neolithic and Early Bronze Age cemeteries in the Little Sea region of Cis-Baikal (the region to the west and north of Lake Baikal) are explored using stable isotopes of carbon and nitrogen. Stable isotope data, including stable carbon isotopes from bone carbonate, are presented for 22 individuals from the site of Kurma XI, dated to approx...

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...

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...

Abstract This chapter aims at summarizing strengths and caveats on the suitability of stable carbon oxygen isotopes in tree rings as recorders for fingerprints environmental influences. First, constraints limiting growth shaping species distribution worldwide are discussed. Second, examples presented conditions under which tree-ring record signals particularly well, but also cases where physiol...