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Evidence For Disease Mediated Extinction: Correlation Between An Introduced Pathogen And Extinction Of Rattus Macleari On Christmas Island, Kelly B. Wyatt
Evidence For Disease Mediated Extinction: Correlation Between An Introduced Pathogen And Extinction Of Rattus Macleari On Christmas Island, Kelly B. Wyatt
Biological Sciences Theses & Dissertations
The Durham Collection and the Cambridge and Oxford University Museums provided the materials to investigate the possibility that the extinction of indigenous rats of Christmas Island was a result of disease introduced by infected ship rats (R. rattus) in 1899. The collections of H.E. Durham in 1901-1902 reveal that R. macleari was present on Christmas Island up to then and includes specimens of R. rattus together with specimens that exhibit characteristics of both R. rattus and R. macleari. Durham's notes indicate both R. rattus and R. macleari specimens were heavily infected with trypanosomes at the time of collection. In …
The Diet Of Oryzomys Palustris Based On Stomach Content Analysis, Shannon L. Wright
The Diet Of Oryzomys Palustris Based On Stomach Content Analysis, Shannon L. Wright
Biological Sciences Theses & Dissertations
Oryzomys palustris (Harlan) is unusual in that it is one of two carnivorous mammals in the Family Muridae in North America. A diet analysis of Oryzomys palustris. the marsh rice rat, was done based on stomach contents. This was accomplished by taking the animals from two study areas located on the Eastern Shore of Virginia. The animals were taken monthly for one year. Once caught, the animals were sacrificed and their stomach contents were identified to the lowest taxonomic level possible. This study showed that rice rats were omnivorous mammals, eating a variety of foods, including dicots, monocots, crabs, …
Lead Activation Of A Developmentally Regulated Calcium Channel In Rat Hippocampal Nerve Terminals, Troy E. Rhodes
Lead Activation Of A Developmentally Regulated Calcium Channel In Rat Hippocampal Nerve Terminals, Troy E. Rhodes
Theses and Dissertations in Biomedical Sciences
Low level lead (Pb2+) exposure may produce lasting deficits in learning and memory by altering calcium (Ca2+) dependent processes. Isolated presynaptic nerve terminals from rat hippocampus were loaded with the intracellular (Ca2+) indicator Fura-2. The changes in cytoplasmic free calcium ([Ca2+]i) were measured by stopped-flow fluorescence spectroscopy following depolarization with elevated potassium on a millisecond time scale (Lentzner et al., 1992). Depolarization promoted a rapid increase in Ca2+i which occured in two kinetically distinguishable phases: a fast component, representing the activity of rapidly inactivating Ca2+ channels (τ …
A Light And Electron Microscopic Study Of The Rat Olfactory Tubercle: Normal Morphology And Acetylcholinesterase Localization, James Curtis Woodley
A Light And Electron Microscopic Study Of The Rat Olfactory Tubercle: Normal Morphology And Acetylcholinesterase Localization, James Curtis Woodley
Biological Sciences Theses & Dissertations
A cytoarchitectural analysis of the rat olfactory tubercle using Nissl-stained coronal sections revealed that the dense cell layer (DCL) consisted of medium sized striatal cells in the cortical regions and small sized "granule" cells in the cap regions. Also delineated from this experiment was a rim of neuropil, nearly devoid of neurons as well as neuronal processes, outlining the islands of Calleja. Acetylcholinesterase (AChE) localization utilizing light microscopy revealed that the olfactory tubercles (OT) contained AChE-positive fibers that were orientated dorsoventrally in the molecular and multiform layers. The DCL consisted of only fibers en passant and putative terminals. Diisopropylfluorophosphate (DFP) …
Effects Of Ethanol And Caffeine Administered Maternally On Neonatal Adrenocortical Function, Rhonda L. Mullins Rohlfing
Effects Of Ethanol And Caffeine Administered Maternally On Neonatal Adrenocortical Function, Rhonda L. Mullins Rohlfing
Biological Sciences Theses & Dissertations
Two investigations were conducted to determine the effects of maternally administered ethanol and caffeine on neonatal adrenocortical function. In the ethanol study, pregnant female rats were fed a liquid diet in which 35% of the sucrose calories were removed and replaced with ethanol. Dams in the caffeine study were injected with 25 mg/kg/day caffeine in saline solution. Within 24 hours of parturition, neonatal rats in both studies were sacrificed. The adrenal glands were incubated in vitro for one hour and media were analyzed for corticosterone content. Significant adrenal weight differences were found in both studies. The ethanol group pups were …
Acetylcholinesterase In The Neonatal Rat Brain: The Effects Of Prenatal Ethanol Exposure, Linda M. Boland
Acetylcholinesterase In The Neonatal Rat Brain: The Effects Of Prenatal Ethanol Exposure, Linda M. Boland
Biological Sciences Theses & Dissertations
Acetylcholinesterase (AChE) activity in the neonatal rat brain was determined by histochemical localization and quantitative biochemical analysis. AChE-positive perikarya were concentrated in the neostriatum, globus pallidus, medial habenular nucleus, amygdaloid complex, various hypothalamic nuclei, gigantocellular and paragigantocellular reticular nuclei, raphe nuclei, locus coeruleus, and motor nuclei of cranial nerves III-VII and IX-XII. Some areas stained differently or not at all when compared with the adult rat brain. The effects of prenatal ethanol exposure on regional AChE activity were assessed by comparing enzyme levels in offspring exposed via maternal consumption of a liquid diet containing 35 percent ethanol derived calories. This …