This study evaluated the efficacy of the Stages of Behavior Change (SBC) Model for use with Hong Kong Chinese. The SBC Model has demonstrated empirical support in a variety of health behaviors and across diverse populations. Further, the SBC has implications for the development of behavior change interventions. The SBC is composed of three components: stages of change, self-efficacy, and decisional balance. The stages of change are used to determine intention and time frames for behavior change. The SBC model applies Bandura's (1977) definition of self-efficacy and Janis and Manns’ (1968, 1977) conflict theory of decision making. The surveys used to measure these components have been validated and are predictive for condom acquisition. Survey data related to HIV/AIDS prevention (condom use) were collected from university students in Hong Kong and the United States. Comparisons were made across cultures (Hong Kong and the United States) and within the two cultural groups. Exploratory factor analyses using Principal Components Analysis revealed a single-factor model for self-efficacy and a 4-factor model for decisional balance (2 factors for advantages and 2 factors for disadvantages) concerning self (1) and others (we). Main effects for culture and staging were found for self-efficacy and the disadvantage component of decisional balance. Main effects for stage were found for advantages with a significant interaction. These data described an increase in self-efficacy across the stages of change for condom use and greater self-efficacy in HK then the US. The hypotheses for this study were supported with the exception of the advantages component of decisional balance within Hong Kong. Post hoc tests found no difference in self-efficacy in sexually active versus sexually non-active subjects in HK and the US and demonstrated differences in sexually active versus sexually non-active subjects in HK for advantages and disadvantages. Results offer support for using this model with Hong Kong Chinese as the data suggest more similarities than differences across two diverse cultures. These results have important implications for understanding behavior change mechanisms in diverse cultural groups and have significance for intervention planning in Hong Kong for AIDS risk reduction. / Ph. D.

Made available in DSpace on 2014-12-17T15:36:36Z (GMT). No. of bitstreams: 1 MarinoEAN_TESE.pdf: 1510121 bytes, checksum: 824b52d7ab71a45fa42ff2c16c22da7c (MD5) Previous issue date: 2011-02-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Shrimp farming in Brazil is a consolidated activity, having brought economical and social gains to several states with the largest production concentrated in the northeast. This fact is also reflected in higher feed intake, necessitating a more efficient feed management. Currently, management techniques already foresee food loss due to molting. In this sense, studies relating shrimp s digestive physiology, molting physiology and behavioral response of shrimp feed can optimize the feed management. Thus, our study aimed to evaluate the behavioral response of the marine shrimp L. vannamei (Crustacea: Penaeidae) in accordance with the stages of moulting cycle and feeding schedules based on higher or lower activity of proteolytic digestive enzymes; also, to investigate the influence of feeding schedule on hepatosomatic index and non-specific and specific protease activity (trypsin). Experiments were carried out at the Laboratory of Shrimp Behavioral Studies at UFRN in partnership with the Laboratory of Enzimology UFPE. Juveniles of L. vannamei weighting 5.25 g (+ 0.25 g) were kept in aquaria at a density of 33 shrimp m -2. In the first experiment, shrimp were fed in the light phase or in the dark phase for 8 days; in the ninth day, the animals were observed for 15 minutes every hour during the 12 hours of each phase of the photoperiod. We recorded the frequency of inactivity, exploration, food intake, burrowing, swimming and crawling behavior. At the end of the 12th observation session, the shrimp were sacrified and classified by the method of setogenesis in the molt cycle stages A, B, C, D0, D1, D2 or D3. We found that the shrimp in A stage show high levels of inactivity. Moreover, the frequency of food intake was very low. The shrimp in D3 stage also had low food intake and high inactivity associated with elevated frequencies of burrowing. In the second experiment, shrimp were kept in physiological acclimation to experimental conditions for 28 days, distributed in 12 treatments in the light phase and 12 treatments in the dark phase. In the end, the animals were sacrified and dissected to assess non-specific and specific protease activity (trypsin) activity. In general, these parameters did not vary among animals fed in the light phase and those fed in the dark phase. However, significant differences were found in the activity of specific and nonspecific proteases in relation to food treatment. In the light phase, the major proteolytic activities converged to 10 hours after the start of the light phase, while the lowest activities converged to 6 hours after the beginning of this phase. In the dark phase, the highest enzyme activity converged to 12 hours after the onset of phase, while the lowest activities converged to 3 hours after the onset of phase. In the third experiment, we sought to evaluate the behavioral responses of shrimp in relation to dietary treatments based on higher or lower activity of proteolytic enzymes, considering the results of the second experiment. The behavioral categories observed were the same as the ones in the first experiment, with observations of 30 minutes (15min before and 15min after food supply). We found variation in behavioral responses as a function of the treatments, with greater intake of food in shrimp fed during the period of greatest activity of proteolytic enzymes, in the light phase. Thus we see that periodic events associated with the shrimp s physiology interfere in their behavioral responses, revealing situations that are more adjustable to the provision of food, and consequently optimizing feeding management / A carcinicultura brasileira ? uma atividade consolidada, pois trouxe ganhos econ?micos e sociais a v?rios estados, com a maior produ??o e ?rea cultivada localizada na regi?o nordeste. Esse fato tamb?m se reflete no maior consumo de ra??o, tornando necess?rio um manejo alimentar mais eficiente. Atualmente, as t?cnicas de manejo j? prev?em sobra alimentar em decorr?ncia dos processos de muda. Nesse sentido, estudos relacionando fisiologia digestiva, fisiologia da muda e resposta comportamental do camar?o podem otimizar o manejo alimentar. Assim, nosso trabalho teve o objetivo de avaliar a resposta comportamental do camar?o marinho L. vannamei (Crustacea: Penaeidae) de acordo com os est?gios do ciclo de muda e com a alimenta??o baseada em hor?rios de maior ou de menor atividade de enzimas digestivas proteol?ticas, bem como investigar a influ?ncia do hor?rio de alimenta??o sobre o ?ndice hepatossom?tico, atividade de protease espec?fica (tripsina) e n?o espec?fica. Para tanto, foram realizados tr?s experimentos no Laborat?rio de Estudos do Comportamento de Camar?es Departamento de Fisiologia da UFRN, em parceria com o Laborat?rio de Enzimologia Departamento de Bioqu?mica da UFPE. Juvenis de L. vannamei pesando 5,25 g (+ 0,25 g), foram mantidos em aqu?rios a uma densidade de 33 camar?es m-2. No primeiro experimento, os camar?es foram alimentados na fase de claro ou na fase de escuro durante 8 dias; no nono dia, os animais foram observados por 15 minutos a cada hora, durante as 12 horas de cada fase do fotoper?odo, sendo registradas as freq??ncias de ocorr?ncia dos comportamentos parado, explora??o, ingest?o de alimento, enterramento, nata??o e rastejamento. Ao final da 12? sess?o de observa??o, foram sacrificados e classificados pelo m?todo da setog?nese, nos est?gios do ciclo de muda A, B, C, D0, D1, D2 ou D3. Como resultado, encontramos que os camar?es em est?gio A apresentam elevada frequencia do comportamento parado. Por outro lado, a freq??ncia de ingest?o de alimento foi muito baixa. Os camar?es em est?gio D3 tamb?m apresentaram baixa ingest?o de alimento e elevada inatividade, associada a elevadas freq??ncias de enterramento. No segundo experimento, os camar?es foram mantidos em aclimata??o fisiol?gica ?s condi??es experimentais por 28 dias, distribu?dos em 12 tratamentos na fase de claro e 12 tratamentos na fase de escuro. Ao final, os animais foram sacrificados e dissecados para avalia??o da atividade de protease espec?fica (tripsina) e atividade de protease n?o espec?fica. De modo geral, esses par?metros n?o variaram entre os animais alimentados na fase de claro e aqueles alimentados na fase de escuro. No entanto, percebemos diferen?as significativas na atividade das proteases espec?fica e n?o espec?fica em rela??o ao tratamento alimentar. Na fase de claro, as maiores atividades proteol?ticas convergiam para a 10? hora ap?s o in?cio da fase de claro, enquanto as menores atividades convergiram para a 6? hora ap?s o in?cio dessa fase. Na fase de escuro, as maiores atividades dessas enzimas convergiram para a 12? hora ap?s o in?cio da fase, enquanto as menores atividades convergiram para a 3? hora ap?s o in?cio da fase. No terceiro experimento, buscamos avaliar as respostas comportamentais dos camar?es a tratamentos alimentares baseados na maior ou menor atividade de enzimas proteol?ticas, considerando os resultados do segundo experimento. As categorias comportamentais observadas foram ?s mesmas do primeiro experimento, com observa??es de 30 minutos (15min antes e 15min depois da oferta alimentar). Encontramos uma varia??o na resposta comportamental em fun??o dos tratamentos, com maior ingest?o de alimento nos camar?es alimentados no hor?rio de maior atividade de enzimas proteol?ticas, da fase de claro. Assim, percebemos que eventos peri?dicos associados ? fisiologia dos camar?es interferem em suas respostas comportamentais, revelando situa??es mais prop?cias ? oferta de alimento, capazes de otimizar o manejo alimentar