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2006

Graduate Theses, Dissertations, and Problem Reports

Animal Physiology

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Afferent Regulation Of A15 Dopamine Neurons In The Ewe, Adrienne L. Bogusz Dec 2006

Afferent Regulation Of A15 Dopamine Neurons In The Ewe, Adrienne L. Bogusz

Graduate Theses, Dissertations, and Problem Reports

Ovine reproduction is characterized by a breeding season and an anestrous season. Seasonal anestrus is induced by increased responsiveness of the GnRH neurosecretory system to estrogen (E) negative feedback. Previous studies have shown that inhibitory A15 dopamine neurons mediate this increased sensitivity to E, however, these neurons lack E receptors. In this thesis we performed three experiments. For experiment 1 we looked at the specific sites of actions that thyroid hormones act to cause neuronal plasticity of A15 DA neurons, utilizing dual-labeled immunocytochemistry. The results of this study demonstrated no change in dendrite morphology or the number of close contacts …


The Extrinsic Apoptotic Pathway In Aged Skeletal Muscle: Roles Of Tumor Necrosis Factor-Alpha And Interleukin-15, Emidio E. Pistilli Dec 2006

The Extrinsic Apoptotic Pathway In Aged Skeletal Muscle: Roles Of Tumor Necrosis Factor-Alpha And Interleukin-15, Emidio E. Pistilli

Graduate Theses, Dissertations, and Problem Reports

Apoptosis is implicated in the loss of skeletal muscle mass following periods of reduced activity (i.e.-disuse) as well as during the normal aging process (i.e.-sarcopenia). Aging is also characterized by elevations in circulating cytokines, specifically TNF-alpha, which has been associated with the sarcopenic process. The specific signaling components that participate in the pro-apoptotic pathway downstream of the type I TNF receptor (i.e.-extrinsic apoptotic pathway) within skeletal muscle have not been clarified. Additionally, few studies have been performed with the aim of disrupting this apoptotic pathway, and thereby sparing muscle mass in the aged. Therefore, the purposes of this dissertation were …


Soluble Metals Of Residual Oil Fly Ash Alter Pulmonary Host Defense In Rats, Jenny Renee Roberts May 2006

Soluble Metals Of Residual Oil Fly Ash Alter Pulmonary Host Defense In Rats, Jenny Renee Roberts

Graduate Theses, Dissertations, and Problem Reports

Incidences of high levels of air pollution have been correlated with increased morbidity and mortality in susceptible populations. Inhalation of the combustion-derived pollutant, residual oil fly ash (ROFA), has been shown to impair lung defense mechanisms in laboratory animals and susceptible populations. The hypothesis of these studies was that the soluble metals in ROFA would increase susceptibility to pulmonary infection in rats, and that the primary metal responsible for the increase is soluble Ni. To investigate the hypothesis, three specific aims were established: (1) determine if soluble metals in ROFA cause a decrease in bacterial clearance from the lungs of …


Effects Of Environmental Factors On The Paternal Brood Pouch And Sound Production In Two Sympatric Pipefish Species From The Chincoteague Bay, Virginia, Jennifer L. Ripley May 2006

Effects Of Environmental Factors On The Paternal Brood Pouch And Sound Production In Two Sympatric Pipefish Species From The Chincoteague Bay, Virginia, Jennifer L. Ripley

Graduate Theses, Dissertations, and Problem Reports

Pipefishes and seahorses of the family Syngnathidae are important inhabitants of diminishing grass beds threatened by excessive nutrient loads, sedimentation, and chemical contaminants. This research examined the influence of these environmental factors on two sympatric pipefishes from the Chincoteague Bay, Virginia. Syngnathids are characterized by a unique mode of reproduction in which the male carries developing embryos in a placenta-like ventral brood pouch until the fry are free-swimming. Interspecific comparisons revealed differences in parental nutrient allocation to embryos. In Syngnathus fuscus, females produce nutritionally poor eggs and males implant developing embryos adjacent to blood vessels. The loose connection between eggs …


Tumor Necrosis Factor-Alpha Production Induced By Peptidoglycan-Polysaccharide In Early Pregnant Ewes, Gabrielle Marie Rogers Jan 2006

Tumor Necrosis Factor-Alpha Production Induced By Peptidoglycan-Polysaccharide In Early Pregnant Ewes, Gabrielle Marie Rogers

Graduate Theses, Dissertations, and Problem Reports

Peptidoglycan-polysaccharide (PG-PS), cell wall component of gram-positive bacteria, was used to intoxicate sheep to study mastitis-related reproductive failure, mediated by TNF-alpha. Estrus was synchronized in ten adult Suffolk ewes. Four days after mating (Day 0) the jugular and posterior vena cava (saphenous vein) were catheterized. On Day 5, ewes were assigned randomly to either: control group (n = 4, 0.9% NaCl), or PG-PS group (n = 6, 30 mug/kg BW, i.v.). Plasma samples were collected from both jugular and saphenous vein catheters every 15 minutes for 6 hours. Radioimmunoassay quantified concentrations of TNF-alpha. Data were analyzed using repeated-measures analysis of …