Diss.--Philosophischen Fakultät--Universität Zürich, 1988. / Bibliogr. p. 417-424.

No description available.

Texte remanié de: Th. doct.--Leiden, Pays-Bas--Universiteit Leiden, 2003. / Bibliogr. p. 225-239. Index.

Inaug.-Diss.--Bonn. / Added t.p., with thesis statement, inserted.

Thesis (D. Min.)--Abilene Christian University, 2005. / Includes abstract. "May 2005." Includes bibliographical references (leaves 83-85).

Thesis (D. Min.)--Abilene Christian University, 2005. / Includes abstract. "May 2005." Includes bibliographical references (leaves 83-85).

Resumo: Os dramaturgos gregos basearam as suas peças em fatos mitológicos e históricos que receberam uma interpretação trágica. Dentro deste contexto, Jack Richardson, que tem um profundo conhecimento da tragédia Grega, também tenta inserir alguns acontecimentos políticos e históricos que afetam a Civilização Moderna dentro da estrutura do mito de Orestes. Em sua peça, The Prodigal, que está sendo analisada nesta dissertação, ele enfoca a Guerra de Tróia e, como acontece em todas as guerras, os soldados que voltam, como os cidadãos de Argos, são atingidos pelas conseqüências psicológicas de após-guerra de exaustão e fadiga. Na peça citada acima, a dimensão política é fundamental e constitui uma espécie de leitmotiv que sustenta a ação. O autor demonstra um interesse especial pela função política do homem - a estrutura política determina os aspectos sociais e religiosos nesta peça. Em um texto literário, o aspecto político não transporta valor por si só, mas, pode significar um elemento essencial de sua estrutura. Richardson dramatiza a sua teoria de Evolução Histórica em The Prodigal pondo em evidência as razões e circunstâncias que causam a queda de uma Instituição, que não pode manter os seus valores fundamentais contra uma nova mentalidade que emerge. Ele analisa as divergências políticas, a sociologia da família e discute argumentos religiosos, literários e filosóficos, tendo como modelos os personagens da antiga mitologia. O principal objetivo desta dissertação é determinar a teoria de Evolução Histórica de Jack Richardson em The Prodigal. A minha intenção é comparar a peça moderna com a Oréstia de Ésquilo para determinar até que ponto os dois dramaturgos sustentam os mesmos pontos de vista e quais especificamente são as inovações introduzidas por Jack Richardson.

Competition is defined as the demand of two or more organisms for the same extrinsic resources in excess of supply. The distribution, movements, behaviour and food of trout and shiners in Paul and Pinantan lakes were studied in order to determine the item's and mechanisms of interspecific competition between them. Data from recent years were compared with data for years when trout alone inhabited the lake. No interspecific aggression was observed. The possibility that the two species were competing for space was discounted. Stomach contents of shiners in Pinantan Lake revealed a marked qualitative diurnal food cycle. In Paul Lake, shiners have drastically reduced the Gammarus population relative to its pre-shiner abundance. This overgrazing was caused by the concentration of large numbers of shiners over the shoals where Gammarus are also present in their highest concentrations and the ability of shiners to pursue food deeper into the weeds and to graze an area more thoroughly than trout. In Pinantan Lake shiners have apparently-reduced the density of Daphnia to a point where trout are unable to feed on them as rapidly as in pre-shiner years. The ability of both species to utilize many types of food tends to reduce the intensity of competition. The study demonstrates how false implications may arise from a delayed appraisal of competition. If observations had not been made on Paul Lake until after competition had been observed the importance of Gammarus as an item of competition would have probably been overlooked and the whole competitive relationship misconstrued. Included among the basic mechanisms of competition is the consumption by one or more organisms of something in short supply before it reaches a potential habitat where it would become available to another organism or group. Environmental factors and behaviour were shown to be important influences in the dynamics of competition. The physical and biological environment and the distribution and behaviour of competitors may be in states of continual flux. Hence natural competitive relationships can be considerably more complicated and variable than situations described by the most elastic of theoretical models. / Science, Faculty of / Zoology, Department of / Graduate

Richardson ground squirrels (gophers) are pests on the prairies that cause considerable agricultural and ecological damage. Traditional control methods such as the rodenticides strychnine, zinc phosphide, and anticoagulants, have proven ineffective in reducing gopher densities. In additional, current gopher control methods have the significant potential to cause primary and secondary toxicity to non-target animals. Thus, alternative methods for toxicological control of gophers are needed to mitigate these concerns. Present studies focused on the cytochrome P450 (CYP450) enzyme system responsible for xenobiotic detoxification in gophers. In vitro hepatic microsomal systems and HPLC analysis were used to elucidate general metabolic characteristics of major gopher xenobiotic metabolizing pathways. We found that the content and activity of individual components of the CYP450 system including CYP450, cytochrome b5, and NADPH-cytochrome P450 reductase in liver microsomal preparations were higher in gophers exposed to toxins used to control their population than in naïve (unexposed) gophers. When in vitro CYP450 mediated activities for five substrates [coumarin and aniline aromatic hydroxylation, 7-methoxycouamrin O-demethylation, and N-methylaniline, and N,N-dimethylaniline N-demethylation] were measured, naïve gophers were identified to have higher specific activity but similar whole body activity compared to the exposed gophers. Furthermore, there was a clearly identifiable sub-population of poor metabolizers showing considerably lower CYP450 activity within the gopher samples studied. Clotrimazole was found to be a potent inhibitor of several substrates of CYP450 enzyme-mediated reactions, which included aniline aromatic hydroxylation, N-methylaniline and N,N-dimethylaniline N-demethylation, and 7-methoxycoumarin O-demethylation. The cytotoxicity of above compounds was tested using freshly isolated gopher hepatocytes. The results showed that each compound caused considerable cytotoxicity to gopher hepatocytes. Addition of clotrimazole to the freshly isolated hepatocyte suspension increased the cytotoxicity of all tested compounds. <p>In conclusion, gophers may develop resistance to current chemical control methods through the enhancement of CYP450 system content, which can compensate the loss of enzyme activity. Furthermore, clotrimazole is a potent cytochrome P450 inhibitor, which increases the cytotoxicity caused by given compounds in gopher livers. The concept of using CYP450 enzyme inhibitor in combination with another chemical whose elimination depends on CYP450 metabolism to improve current gopher control method has practical importance.

Richardson ground squirrels (gophers) are pests on the prairies that cause considerable agricultural and ecological damage. Traditional control methods such as the rodenticides strychnine, zinc phosphide, and anticoagulants, have proven ineffective in reducing gopher densities. In additional, current gopher control methods have the significant potential to cause primary and secondary toxicity to non-target animals. Thus, alternative methods for toxicological control of gophers are needed to mitigate these concerns. Present studies focused on the cytochrome P450 (CYP450) enzyme system responsible for xenobiotic detoxification in gophers. In vitro hepatic microsomal systems and HPLC analysis were used to elucidate general metabolic characteristics of major gopher xenobiotic metabolizing pathways. We found that the content and activity of individual components of the CYP450 system including CYP450, cytochrome b5, and NADPH-cytochrome P450 reductase in liver microsomal preparations were higher in gophers exposed to toxins used to control their population than in naïve (unexposed) gophers. When in vitro CYP450 mediated activities for five substrates [coumarin and aniline aromatic hydroxylation, 7-methoxycouamrin O-demethylation, and N-methylaniline, and N,N-dimethylaniline N-demethylation] were measured, naïve gophers were identified to have higher specific activity but similar whole body activity compared to the exposed gophers. Furthermore, there was a clearly identifiable sub-population of poor metabolizers showing considerably lower CYP450 activity within the gopher samples studied. Clotrimazole was found to be a potent inhibitor of several substrates of CYP450 enzyme-mediated reactions, which included aniline aromatic hydroxylation, N-methylaniline and N,N-dimethylaniline N-demethylation, and 7-methoxycoumarin O-demethylation. The cytotoxicity of above compounds was tested using freshly isolated gopher hepatocytes. The results showed that each compound caused considerable cytotoxicity to gopher hepatocytes. Addition of clotrimazole to the freshly isolated hepatocyte suspension increased the cytotoxicity of all tested compounds. <p>In conclusion, gophers may develop resistance to current chemical control methods through the enhancement of CYP450 system content, which can compensate the loss of enzyme activity. Furthermore, clotrimazole is a potent cytochrome P450 inhibitor, which increases the cytotoxicity caused by given compounds in gopher livers. The concept of using CYP450 enzyme inhibitor in combination with another chemical whose elimination depends on CYP450 metabolism to improve current gopher control method has practical importance.