The western United States has experienced large-scale degradation due to land use and land cover changes, invasion of annual grasses, and expansion of woody plants into grass and shrublands and the resultant altered fire regimes. These landscape-scale changes have coincided with declining mule deer (Odocoileus hemionus) populations, making habitat loss...
Twenty seven modern (top 1-2cm) sediment samples from multicores retrieved from throughout coastal SE Alaska were analyzed for their organic matter content and the source composition. Total organic carbon (TOC) as well as biogenic silica (bioSi), and calcium carbonate (CaCO3) content were analyzed to evaluate the organic matter content and...
Energetic resources transferred between distinct habitats or ecosystems, referred to as allochthonous resources, can greatly subsidize consumers in the recipient habitat, and thus influence food web structure and dynamics. Such subsidies may allow the growth of the consumer population to be decoupled from in situ productivity with effects on consumer...
Fecal glucocorticoid metabolites (FGMs) are commonly used as indicators of an animal’s stress response in behavioral and eco-physiological studies. Stress in wild animals represents an immediate measure of the physiological response to changes in the environment, and, potentially, a prospective assessment of the animal’s health and well-being. In wild mammals,...
Combustion emissions produced from burning real transportation fuels have many environmental impacts. However, detailed chemistry across multiple phases, time scales, and thermodynamic conditions make predicting combustion emissions challenging. Detailed modeling of the gas phase alone is prohibitively expensive, due to the large size and stiffness of the kinetic models. The...
Large areas of non-coniferous communities in southwestern Oregon are thinned to reduce fire hazard and accomplish ecosystem restoration, under the assumption that current fuel loads are unnaturally high. Although Oregon white oak (Quercus garryana) woodlands are a characteristic landscape component in this region, little is known about their current or...
Interferon tau (IFN-τ) is the pregnancy recognition signal secreted by the trophectodermal cells of the developing bovine embryo that prevents luteolysis and maintains critical progesterone production. Recent evidence has suggested in addition to the mechanism of action identified in the uterus, there may be a direct effect of IFN-τ on...
Large barite (BaSO4) structures mark cold seeps in the southern San Clemente Basin. Barium flux to San Clemente sediments is two to three times greater than fluxes measured in surrounding California Borderland basins. Analyses of sediment trap material, water column samples, sediments and pore water indicate that expected bariumbearing mineral...
A three-part study was conducted into the impact of physiological and ecological variables on the net isotopic fractionation of hydrogen, α[subscript K₃₇], expressed in C₃₇ alkenones. First, alkenone-producer production, abundance, and export were characterized in the summertime Gulf of California and Eastern Tropical North Pacific using compound-specific, labeled in situ...
Recent works have investigated use of the hydrogen isotopic composition of C₃₇ alkenones (δD[subscript K37s]), lipid biomarkers of certain haptophyte microalgae, as an independent paleosalinity proxy. I discuss herein the factors impeding such an application and identify the potential alternative use of δD[subscript K37s] measurements as a proxy for non-thermal,...