Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 76-78). Also available via the Internet.

Thesis (Ph. D.)--University of Hawaii at Manoa, 1995. / Includes bibliographical references (leaves 121-123). / Microfiche. / xvii, 123 leaves, bound ill. 29 cm

Thesis (Ph. D.)--University of Rhode Island, 2005. / Typescript. Includes bibliographical references (leaves 120-131).

Bibliography: leaves 129-146. / ix, 146 leaves : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The studies described in this thesis are concerned with the release, diffusion through dentine, local pharmacology and local toxicology of active components of materials which are applied to teeth with therapeutic intent. The method of study of zinc oxide-eugenol (ZOE) release is combined with test methods for cytotoxicity in vitro to give a new model system for the prediction of pulpal toxicity of restorative materials where the potential toxins might be unknown. / Thesis (D.D.S.)--University of Adelaide, Dept. of Dentistry, 1990

M.Sc. / The upper catchment of the Olifants River, from its origin near Bethal, to its confluence with the Wilge River, north of Witbank, as well as it tributaries, are being subjected to increasing afforestation, mining, power generation, irrigation, domestic and industrial activities. These activities have a profound effect on the water quality and the major point sources of pollution in this area include mines, industries and very importantly, combined sewage purification works, located alongside the river, which, in addition to oxidizable material contains detergents, nutrients, and metals. It was therefore necessary to determine the extent to which these activities affect the water quality of the system. The impact of these activities was therefore addressed by a Water Research Commision Project namely "Lethal and sublethal effects of metals on the physiology of fish" of which the present study investigated effects at two localities, namely in the Olifants River (locality OR1) before its confluence with the Klein Olifants River and a locality in the Klein Olifants River (locality KOR1). Apart from the field study, toxicity tests were also performed in a laboratory, in order to determine the effects of low pH and elevated aluminium concentrations on the haematology, osmoregulation and carbohydrate metabolism of the Mozambique Tilapia, Oreochromis mossambicus as the acidification of soil systems may cause the transfer of aluminium into aqueous solutions, where it may be present in different forms. During the field study, the chemical and physical characteristics of the river water were evaluated, with special attention to the concentrations of certain metals (manganese, copper, chromium, lead, nickel, zinc, iron and aluminium) in the water and sediment, as well as in fish, which are known to accumulate the elements supra and are therefore valuable as indicators of these pollutants. The two fish species used for the investigations were the African sharptooth catfish, Clarias gariepinus and the moggel, Labeo umbratus. Four tissue types were dissected, namely the muscle, liver, skin and gill tissues. The metal concentrations in these organs/tissues, as well as in the water and sediment, were determined in a laboratory with an atomic absorption spectrophotometer. Statistical analyses were performed on the results obtained from this study and the order and extent of bioaccumulation of these metals in the water and sediment were determined, as well as in the fish organs/tissues. Its dependence on the size, sex and species of the fish and the localities and seasons were investigated.

Fifteen calves of two sires were fed endophyte infected (E + ) fescue seed to quantify differences in susceptibility to fescue toxicosis among sire groups. One of the sires, a Polled Hereford, had a commercial reputation of producing calves with less severe symptoms of tall fescue toxicosis than their contemporaries. The control sire, also a Polled Hereford, had unknown merit with regard to offspring susceptibility to fescue toxicosis. The study was divided into five phases, two in which endophyte-infected fescue seed was included in the diet (phases two and four) and three in which fescue seed was not in the diet (phases one, three, and five). All calves were treated similarly and given the same opportunities for water, shade and socialization. Susceptibility to fescue toxicosis was measured by appetite (amount of feed consumed per day per unit of metabolic body weight), serum prolactin, cholesterol, and alkaline phosphatase concentrations, ability to maintain homeotherny (afternoon minus morning rectal temperature), ability to dissipate core body heat (afternoon minus morning surface temperature), and heat-transfer inefficiency (afternoon rectal minus afternoon surface temperatures). Appetite was decreased by the E + fescue seed, but the sire groups did not differ in their response to or recovery from E + fescue seed. The E + fescue seed caused prolactin to decrease (P < .0001) but the sire groups did not differ in their responses to addition or withdrawal of E + fescue seed from the diet. Cholesterol levels were lower overall (P < .001) when the E+ fescue seed was fed, and the sire groups recovered from the fescue toxicity at different rates (P < .001). Alkaline phosphatase concentrations were lower during the phases when E + fescue seed was fed; calves from the control sire were less resistant to the E + fescue seed effects than the Missouri calves (P < .0001). Ability to maintain homeothermy was reduced by the E + fescue seed, but the reduction did not differ between sire groups. Surface temperature changes and heat-transfer inefficiencies were not indicative of fescue toxicosis in this study. It was concluded that serum cholesterol and serum alkaline phosphatase concentrations may be accurate indicators of differences among paternal half sib groups of cattle in susceptibility to fescue toxicosis. / Master of Science