Made available in DSpace on 2015-06-17T19:34:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-08-04. Added 1 bitstream(s) on 2015-06-18T12:48:57Z : No. of bitstreams: 1 000831234.pdf: 626479 bytes, checksum: fc33748b7fab005e12ea3d5bcc46bad2 (MD5) / Eritrócitos têm sido utilizados para investigar dano oxidativo e possíveis intervenções com antioxidantes no envelhecimento. O chá mate (CM) ou Ilex paraguariensis reduz o dano oxidativo, porém sua ação em fêmeas velhas ainda não foi elucidada. Neste trabalho foi investigado pela primeira vez, em ratas velhas na perimenopausa, o efeito tempo-dependente do tratamento com CM sobre o dano oxidativo e a defesa antioxidante. Os animais foram divididos em Adulta-controle (5 meses de idade), Velha-Basal (17 meses de idade), Velha tratada e não tratada. Os grupos tratados receberam CM diariamente (20 mg/kg m.c., gavagem) durante duas, quatro e seis semanas, e não tratados receberam água. A capacidade antioxidante plasmática (FRAP), malonaldeído (MDA) e as atividades da superóxido dismutase (SOD), catalase (CAT) e glutationa peroxidase (GPx) foram avaliadas nos eritrócitos. No grupo Velha-basal houve redução de FRAP e das enzimas antioxidantes, e aumento de MDA em comparação ao Adulta-controle. O CM aumentou FRAP, SOD e GPx, e reduziu MDA, após quatro e seis semanas, mas não alterou CAT. Os resultados indicam que o CM é um tratamento promissor para reduzir o acúmulo de dano oxidativo associado à idade em eritrócitos de fêmeas na perimenopausa e que o efeito na FRAP é cumulativo / Erythrocytes have been used to investigate oxidative damage and possible intervention with antioxidant in aging. Mate tea (MT) or Ilex paraguariensis reduces oxidative damage, but its action on aged females has not yet been elucidated. It was investigate, for the first time, in natural aged rats in perimenopause the time-dependent effect of MT treatment on oxidative damage and antioxidant defenses. Animals were divided into Adult-control (5 months old), Aged-baseline, Aged treated and Aged untreated. Treated groups received MT daily (20 mg/kg body weight, gavage) for two, four or six weeks, aged untreated group received water by gavage. Plasma antioxidant capacity, determined by ferric reducing antioxidant power (FRAP) assay, malondialdehyde levels (MDA) and the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) enzymes were evaluated in erythrocytes. Aged-baseline animals (17 months) had decreased FRAP and enzymatic antioxidant defenses and increased MDA when compared to Adult-control (5 months). MT treatment increased FRAP, SOD, GPx, and decreased MDA after four weeks, but did not change CAT. MT is a promising treatment to reduce the accumulation of age-related oxidative damage in erythrocytes in aged rats in perimenopause and the effect is cumulative in FRAP

Orientador: Ana Cláudia de Melo Stevanato Nakamune / Coorientador: Adriane Belló-Klein / Banca: Fábio Erminio Mingatto / Banca: Ana Lúcia dos Anjos Ferreira / Resumo: Eritrócitos têm sido utilizados para investigar dano oxidativo e possíveis intervenções com antioxidantes no envelhecimento. O chá mate (CM) ou Ilex paraguariensis reduz o dano oxidativo, porém sua ação em fêmeas velhas ainda não foi elucidada. Neste trabalho foi investigado pela primeira vez, em ratas velhas na perimenopausa, o efeito tempo-dependente do tratamento com CM sobre o dano oxidativo e a defesa antioxidante. Os animais foram divididos em Adulta-controle (5 meses de idade), Velha-Basal (17 meses de idade), Velha tratada e não tratada. Os grupos tratados receberam CM diariamente (20 mg/kg m.c., gavagem) durante duas, quatro e seis semanas, e não tratados receberam água. A capacidade antioxidante plasmática (FRAP), malonaldeído (MDA) e as atividades da superóxido dismutase (SOD), catalase (CAT) e glutationa peroxidase (GPx) foram avaliadas nos eritrócitos. No grupo Velha-basal houve redução de FRAP e das enzimas antioxidantes, e aumento de MDA em comparação ao Adulta-controle. O CM aumentou FRAP, SOD e GPx, e reduziu MDA, após quatro e seis semanas, mas não alterou CAT. Os resultados indicam que o CM é um tratamento promissor para reduzir o acúmulo de dano oxidativo associado à idade em eritrócitos de fêmeas na perimenopausa e que o efeito na FRAP é cumulativo / Abstract: Erythrocytes have been used to investigate oxidative damage and possible intervention with antioxidant in aging. Mate tea (MT) or Ilex paraguariensis reduces oxidative damage, but its action on aged females has not yet been elucidated. It was investigate, for the first time, in natural aged rats in perimenopause the time-dependent effect of MT treatment on oxidative damage and antioxidant defenses. Animals were divided into Adult-control (5 months old), Aged-baseline, Aged treated and Aged untreated. Treated groups received MT daily (20 mg/kg body weight, gavage) for two, four or six weeks, aged untreated group received water by gavage. Plasma antioxidant capacity, determined by ferric reducing antioxidant power (FRAP) assay, malondialdehyde levels (MDA) and the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) enzymes were evaluated in erythrocytes. Aged-baseline animals (17 months) had decreased FRAP and enzymatic antioxidant defenses and increased MDA when compared to Adult-control (5 months). MT treatment increased FRAP, SOD, GPx, and decreased MDA after four weeks, but did not change CAT. MT is a promising treatment to reduce the accumulation of age-related oxidative damage in erythrocytes in aged rats in perimenopause and the effect is cumulative in FRAP / Mestre

Mate selection has garnered much attention in the existing literature. However, most mate selection research has reviewed mate selection preferences and criteria individually. In this study, the researcher attempted to illustrate mate selection as an interactive process in which individuals are affected by external influences, and their mate selection criteria are influenced by their self-appraisals and their perceptions of others' mate selection criteria. Two studies were conducted. Study 1 was based on social exchange theory, sexual strategies theory, and social context frameworks, and used multiple-group structural equation modeling to describe the relationships among gender, receptivity to external influences on mate selection, self-perceived relative mate selection position, and relative mate selection demand, between Chinese and American never-married heterosexual adults. The results indicated that the model fit the data well. Self-perceived relative mate selection position and relative mate selection demand were negatively correlated. Women had a higher relative mate selection demand than men did. Self-perceived relative mate selection position fully mediated the effect of receptivity to external influences on relative mate selection, though the indirect effect was not significant. Path values did not differ between Chinese participants and American participants. Study 2 confirmed that the model fit the data well and replicated all significant correlations among latent variables found in Study 1. Additionally, Study 2 found that receptivity to external influences and self-perceived relative mate selection position were positively correlated, and that receptivity to external influences had a negative indirect effect on relative mate selection demand, fully mediated by relative mate selection position. Lastly, the researcher discussed findings, implications, strengths, limitations, and future directions of the present study. / Ph. D.

Sementes de llex paraguariensis St. Hil. (erva-mate) necessitam, "in situ", de um longo período para germinar - 6 a 8 meses - e a percentagem de germinação é muito baixa. Quando os embriões são excisados e cultivados "in vitro", a embriogênese pode completar-se em duas semanas. As causas quanto a esses aspectos do desenvolvimento embrionário tardio ainda não estão bem esclarecidas. A interrupção da embriogênese "in vivo" deve-se, provavelmente, à imaturidade do embrião. O baixo índice germinativo pode estar sendo causado por degeneração prematura do suspensor, em alguma das fases desse desenvolvimento. Visando contribuir para a elucidação desse problema, foram fe itos estudos morfoanatômicos - tanto em material fresco como em material fixado - nas diversas fases do desenvolvimento embrionário, em pirenos de l/ex paraguariensis , cultivados a campo durante doze meses. Lotes foram coletados em intervalos de aproximadamente vinte dias e analisados, permitindo a constatação de mudanças estruturais tais como, formação de cotilédones, aumento gradativo do eixo embrionário, diferenciação de tecidos e espessamento helicoidal de elementos de condução. Pôde-se observar, particularmente, a presença do suspensor, órgão identificável em estrutura embrionária, durante as diversas fases da embriogênese, em estágio inicial, como também em estágios mais avançados do desenvolvimento. Testes histoquímicos permitiram verificar a natureza lipoprotéica das reservas do endosperma. Estas reservas, em estágios mais avançados de desenvolvimento embrionário, apresentam-se modificadas, na região próxima ao embrião, mostrando a ocorrência de utilização das mesmas. / The seeds of l/ex paraguariensis St. Hil. (erva-mate) take a long time to germinate - 6 to 8 months - and a high percentage of them fail to develop. When the embryos are excised and cultured "in vitro", embryogenesis may be completed in two weeks. The reasons for this late embryonic development are not quite clear. The interruption of "in vivo" embryogenesis is probably due to embryo imaturity. The low rate of germination is possibly a result of early degeneration of the suspensor during some stage of development. In order to elucidate this problem, morphoanatomical studies were carried out using both fresh and fixed material taken at different stages of embryonic development. l/ex paraguariensis pyrenes were cultivated under field conditions over twelve months. Samples were collectet and analysed at 20 days intervals. Thus, structural changes could be observed, such as the formation of cotyledons, the gradual growth of the embryo axis, tissue differentiation and helicoidal thickening in conduction elements. The suspensor could be found in the embryonary structure during the various stages of embryogenesis ranging from initial to advanced. Histochemical tests demonstrated the lipoproteic nature of the endosperm reserves. In advanced stages of embryogeny, these reserves are modified near the embryo, showing that they are in fact being used.

While the existence of costs of mate choice is well accepted, the effects that these costs have on mating systems and the evolution of mate choice are controversial. The aim of this thesis is to explore a range of different types of costs, including costs of being choosy (using guppies, Poecilia reticulata) and costs of mating with attractive males (using house crickets, Acheta domesticus), and investigate how these costs influence female mating behaviour, sexual selection on males and the evolution of mate choice. I use a range of experimental techniques to investigate these questions including: comparisons of feral populations of guppies (Chapter Two), laboratory experiments that manipulate the social (sex ratio, density; Chapters Three and Four) and physical (water current; Chapter Five) environment in which guppies live, genetic paternity analysis and multivariate selection analysis (Chapter Four). I also conduct longitudinal studies of house crickets that estimate the net fitness consequences (Chapter Six) and indirect effects (Chapter Six and Seven) of mating with attractive males. My results demonstrate that the physical and social environment of individuals are important in determining the costliness of both sexual display and mate choice, and thus influence the mating behaviour of males and females. These differences in mating behaviour are often thought to lead to differences in sexual selection on males. My study of the effects of operational sex ratio and density on multivariate sexual selection, however, indicates that differences in behaviour may not necessarily translate into differences in selection. In contrast to predictions of recent theory, my results also indicate that although there are many costs to being choosy and to mating with attractive males, these may be outweighed by indirect benefits. Hence, despite direct costs of choice, mate choice may evolve via indirect benefits to females. Indirect benefits that are often neglected in sexual selection studies, that I show to be important in determining the net fitness of mating with attractive males, include the attractiveness of sons and the mate choice decisions of daughters. These results highlight the importance of examining the consequences of mate choice over multiple generations.

Swordtail fishes of the genus Xiphophorus have been studied as a model of sexual selection for many years. Many single-trait manipulation studies have been performed, determining female preferences for individual male traits. I characterized how five traits (standard body length, body depth, dorsal fin width, sword length and vertical bar number) correlate to one another within natural variation of populations of X. birchmanni, X. malinche and three hybrid populations and created synthetic 3- dimensional animations exhibiting these traits within ranges of natural variation. I then performed choice tests on females of the above populations using a computer system that automatically played these stimulus videos and simultaneously tracked a female’s position within a test tank to determine female preference for different male phenotypes. Only X. birchmanni females showed significant preferences. Their preferences were in line with past research of univariate trait manipulation experiments. They showed significant preference for larger bodies and dorsal fins and smaller or no swords. They also showed a non-significant preference for vertical bar numbers. My results also confirmed univariate studies in which X. malinche females showed reduced preference for conspecific males and being rather indifferent to the presence of swords. Hybrid females were also shown to have reduced preferences for any specific trait, suggesting that they express recombinant preferences, which can also be explained by reduced color vision at low levels of light.

No description available.

Thesis (M.A.)--University of Hawaii at Manoa, 2004. / Includes bibliographical references (leaves 47-53). / xi, 53 leaves, bound ill. 29 cm

Thesis(M.S.)--Auburn University, 2006. / Abstract. Includes bibliographic references (p.68-78).

Thesis (M.S.W.)--Smith College School for Social Work, Northampton, Mass., 2008. / Typescript. Includes bibliographical references (leaves 42-49).