Thesis (Ph. D.)--University of Wisconsin--Madison, 1975. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1984. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographies.

Thesis (M.S.)--University of Wisconsin--Madison, 1947. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of California at Berkeley, 1993. / Description based on hypertext version as viewed over the World Wide Web; title from web page.

Thesis (M.D.)--University of Hong Kong, 1988. / Also available in print.

Thesis (Ph. D.)--University of Missouri-Columbia, 2007. / "May 2007" The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Vita. Includes bibliographical references.

The Amazon represents more than half of the surviving tropical forest on Earth. However, despite its vast size and diversity, habitat loss is an increasing threat due to the growth of economic activities and infrastructure projects. Carnivores play an important role in reducing herbivore numbers through predation, thereby reducing the risk of over browsing and are particularly susceptible to habitat loss and fragmentation due to their large area requirements, low densities, and slow population growth. Altering herbivore communities via a change in carnivore density and habitat loss may change plant diversity by altering seed dispersal, and seed and seedling survival. The Madeira-Purus interfluvial plain in Brazil is a pristine and yet understudied part of the Amazon. I studied environmental factors affecting occupancy and detection of carnivores and herbivores in the Madeira-Purus interfluvial plain Amazonas state, Brazil. During 2010-12 remote cameras were used to investigate patterns of site occupancy and detection probabilities, as affected by habitat and anthropogenic influences, for several terrestrial mammal groups. Site occupancy and detection varied for all species groups across land protections types. Medium felids and peccaries showed a sharp decline in occupancy from unprotected lands to state-protected sites with the highest occupancy on the federally-protected site. Brocket deer increased in occupancy from unprotected to state-protected lands, and from state-protected to federally-protected lands. Large felid occupancy, however, was exactly the opposite, with the lowest occupancy at the federally-protected site. Species richness at camera sites was the most important covariate, positively influencing occupancy in all species groups. This helps inform wildlife management by providing suggestions to improve future occupancy studies and support for maintaining protected areas for the persistence of viable mammal populations. I found occupancy of many species groups (i.e. peccaries, medium felids and medium rodents) were lowest on state-protected land. Species richness was also lowest on state-protected land, implying a depletion of herbivore and carnivore species in that area, which may be due to local foraging and hunting of forest resources by humans. I recommend stricter laws and enforcement to limit the harvest of forest fruits and nuts and illegal hunting. Repaving local highways will likely increase human influence in these areas and increase pressure on forest resources.

The long terra effects of glucose on the rate of (pro) insulin biosynthesis and the amount of preproinsulin mRNA in rat islets maintained in tissue culture were investigated. The rate of (pro)insulin synthesis was 35 times greater in islets cultured for 6 days in 8 mM glucose than it was in islets cultured in 4 mM glucose. The preproinsulin mRNA content at this time was 2 fold greater in islets incubated with 8 mM glucose compared to 4 mM glucose. The rate of (pro)insulin synthesis and the preproinsulin mRNA content of islets cultured at 8 mM glucose were maximal since no further significant increases were observed in islets cultured at 16 mM glucose for 6 days. These results indicate that the long term effects of glucose on the rate of (pro)insulin synthesis in rat islets of Langerhans is mediated both by transcriptional and translational events and that translational events exert the major controlling influence.

A study of mammals on the Goose Island, British Columbia, was conducted in the summer of 1948. This group of islands represents a well isolated unit typical of many outer fringe islands along the coast. Over and above the qualitative examinations of the fauna, studies were undertaken to obtain some quantitative information upon the ecological distribution of terrestrial mammals. The terrestrial mammalian fauna was represented by three species of small mammals, Peromyscus maniculatus. Microtua longicaudus and Sorex obscurus. Two species of bats also occurred, Lasionycteris noctivagans and Myotis yumanensis. A species of Castor once inhibited the islands. Based on a snap trap procedure the relative abundance of Peromyscus, Microtus and Sorex was determined in four habitats occupied by all three species. The floral composition of these habitats was determined and reasons for the observed distributions postulated. The extent and nature of eight additional habitats have been included as well as notes on pelagic mammals, Myotis, Lasionycteris and Castor. / Science, Faculty of / Zoology, Department of / Graduate

Taurine (2-aminoethane sulfonic acid) is one of the most abundant free amino acids found in mammalian brain, heart and muscle. Taurine levels have also been shown to be altered in certain disease states. A physiological role for taurine in the maintainance of excitatory activity in muscle and nervous tissues has been suggested; however its possible mechanism of action is still uncertain. Early work on the pharmacological actions of taurine involved its possible conversion to isethionic acid (2-hydroxyethane sulfonic acid), a strong anion. This conversion was said to lead to the conductance of cations into the cardiac cell. An analytical technique to measure isethionic acid in mammalian tissues was developed. The method involved extraction, partial purification and methylation with diazomethane, followed by gas-liquid chromatography. With this technique only trace amounts of isethionic acid were detected in rat heart (0.1 mg/lOOg wet weight tissue) and rat brain (0.2 mg per 100 mg wet weight tissue) and none was detected in dog hearts. Recovery of added isethionic acid was between 95 and 100%. The assay was validated using a sample of squid axoplasm. We were also unable to show ¹⁴C-taurine conversion to ¹⁴C-isethionic acid in rat heart slices. Theories on the mode of action of taurine involving bioconversion to isethionic acid were therefore questioned. Some recent work suggested that taurine affects calcium kinetics in perfused guinea-pig hearts and calcium transport in rat skeletal muscle sarcoplasmic reticulum. We have investigated the effect of taurine on ATP-dependent calcium binding and oxalate-dependent calcium uptake in crude preparations of guinea-pig sarcolemma and in microsomal preparations enriched in sarcoplasmic reticulum. Taurine (5-50 mM) was found to have no significant effect on either ATP-dependent Ca²⁺ binding or uptake in both preparations. This result was observed at all calcium concentrations tested (0.5-100 uM) and at all incubation times used (30 seconds to 20 minutes). Taurine (20 mM) neither altered the effect of cyclic AMP-dependent protein kinase on oxalate-dependent calcium uptake nor exerted a stabilization action on calcium transport in these systems. In a further attempt to determine the possible physiological role of taurine in mammalian tissues, we have investigated the effect of taurine on passive transport of sodium, potassium and calcium in synaptosomal preparations of rat brain. Taurine, in a dose dependent manner, was found to have an inhibitory effect on both calcium- uptake and release in these preparations. Amino acids structurally similar to taurine ( β- alanine, homotaurine, hypotaurine and ɣ- aminobutyric acid) were also shown to inhibit calcium uptake in these preparations while a - alanine, proline and valine had no significant effect. Taurine (20 mM), though, did not alter the permeability of these preparations to either sodium or potassium. It thus appeared that taurine, and chemically related amino acids, can specifically alter calcium movements in these preparations. It is suggested that this effect is due to the binding of these agents to taurine receptor sites postulated to be present in these membranes. These observations may help to provide an insight into the physiological and pharmacological effects of taurine reported in cardiac and nervous tissues. / Medicine, Faculty of / Pathology and Laboratory Medicine, Department of / Graduate