Understanding the factors associated with declines of at-risk species is an important first step in setting management and recovery targets. This step can be challenging when multiple aspects of climate and land use are changing simultaneously, and any or all could be contributing to population declines. We analyzed population trends of monarch butterflies in western North America in relation to likely environmental drivers.
View Article and Find Full Text PDFDNA analysis of predator faeces using high-throughput amplicon sequencing (HTS) enhances our understanding of predator-prey interactions. However, conclusions drawn from this technique are constrained by biases that occur in multiple steps of the HTS workflow. To better characterize insectivorous animal diets, we used DNA from a diverse set of arthropods to assess PCR biases of commonly used and novel primer pairs for the mitochondrial gene, cytochrome oxidase C subunit 1 (COI).
View Article and Find Full Text PDFThe reactivity of Fe(0) toward chlorinated ethylenes was examined utilizing a photochemically generated, highly reactive Fe(0) complex. Irradiation of (dmpe)2FeH2 (dmpe = Me2PCH2CH2PMe2) with 360 nm light generated a 16-e(-), Fe(0) intermediate that reacted to dechlorinate chlorinated ethylenes in a stepwise fashion, consistent with a hydrogenolysis dechlorination pathway. The source of the hydrogen atoms in the hydrogenolysis were the hydride ligands of an additional equivalent of (dmpe)2FeH2, as evidenced by deuterium labeling experiments.
View Article and Find Full Text PDFThe photodegradation of imazethapyr, 5-ethyl-2-(4-isopropyl-4-methyl-5-oxo-4,5-dihydroimidazol-1H-3-yl)nicotinic acid, has been investigated in phosphate buffers and in buffered solutions containing natural organic matter (NOM). Imazethapyr degrades most quickly under 253.7 nm light and at pH values >4.
View Article and Find Full Text PDFPrimary astrocyte cultures from neonatal rat brains show uptake of [3H]norepinephrine ([3H]NE). This uptake has a high-affinity component with an apparent Km of approximately 3 X 10(-7) M. At 10(-7) M [3H]NE both the initial rate of uptake and steady-state content of [3H]NE is inhibited by up to 95% by omission of external Na+.
View Article and Find Full Text PDFChronic deficiency of growth hormone was produced in rats by injecting highly specific antibodies against rat somatotropin during the first week of postnatal life. Antisera were prepared by immunizing adult rhesus monkeys with purified rat growth hormone. The rate of body and brain growth was significantly decreased when compared with controls injected with nonimmune serum, and 50-day-old animals showed a profound and apparently specific endocrine deficiency of pituitary growth hormone as measured by bioassay.
View Article and Find Full Text PDFAm J Trop Med Hyg
September 1955