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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Behavior and socioendocrinology of bonobos (Pan paniscus): mechanisms that contribute to the evolution and maintenance of social structure in the other Pan species

Boose, Klaree 10 April 2018 (has links)
Research into the origins of our own social behavior begins with understanding how environmental elements lead to complex social interaction. Social structure emerges from these interactions as a bottom-up process, whose patterning constitutes the very framework of a society. Studies of behavioral mechanisms are important in determining the full repertoire that results in the social and dominance structures of a species. Hormones such as oxytocin and cortisol facilitate and fluctuate in response to social interactions and measuring their relative values among individuals is a valuable tool in testing functional hypotheses of behavioral mechanisms. The objective of this dissertation is to investigate several fundamental, under-, or previously unstudied behavioral mechanisms and hormonal correlates that shape the unique social system of bonobos. The first study describes the pattern of expression of harassment behavior among immatures and tests predictions generated by the Exploratory Aggression and Rank Improvement hypotheses. Results demonstrate that immatures use harassment to test the nature of existing inter-individual relationships and to explore the parameters of aggressive behaviors and furthers our understanding of juvenile development of aggression and integration into the dominance hierarchy. The second study describes the pattern of occurrence of infant handling and tests predictions generated by several functional hypotheses, including examining the relationship between oxytocin and handling behaviors. Results show a significant sex difference in expression of handling where, during adolescence, male interest in infants sharply declines whereas females continue to handle infants, the expression of which was correlated with oxytocin. These results primarily support the Learning-to-Mother hypothesis and provide insight into the role oxytocin may play in facilitating care-giving behaviors in young females. The final study explores the patterning of female sexual behavior and male aggression, and investigates whether male constraint of female choice imposes a cost to females through induction of a stress response. Results show that while females exercise unconstrained mate choice through proceptive behaviors, males influence female receptivity through aggression and sexual coercion, shedding light on the degree to which rank related asymmetry in male mating success reflects female choice vs. constraint of choice. This dissertation includes previously published and unpublished co-authored material.
2

Behavioral Mechanisms of Pramipexole-Induced Impulsivity: Discrimination Processes Underlying Decision-Making

Johnson, Patrick S. 01 May 2012 (has links)
Faced with an intertemporal choice, an organism that chooses a “smaller-sooner” reinforcer over a “larger-later” reinforcer is said to behave impulsively. Individual differences in intertemporal choice are effectively modeled by generalized matching law and delay discounting equations that incorporate parameters corresponding to behavioral processes such as sensitivity to reinforcer amount or delay. By simulating changes in these processes and identifying conditions under which impulsive choice is likely to result, researchers are in a position to anticipate and examine potential behavioral mechanisms underlying clinical instances of impulsivity. Pramipexole, a dopamine agonist medication, is associated with reports of impulsive behavior in populations prescribed the drug, as well as in experimental subjects administered the compound prior to intertemporal choice sessions, although the latter findings are mixed. The present set of experiments was designed (a) to systematically replicate conditions under which pramipexole increased impulsive choice, but also nonspecifically disrupted behavior, and (b) to elucidate behavioral mechanisms of pramipexole-induced impulsivity in rats. In Chapter 2, a behavioral task used previously by researchers reporting a nonspecific effect of pramipexole was modified to include procedural controls common in the intertemporal choice literature (centering response, no-delay sessions). In accord with previous findings, acute pramipexole nonspecifically disrupted choice behavior, while chronic pramipexole partially remediated elements of the disruption (i.e., decrease in initial-block choice). In Chapter 3, three experiments targeted behavioral processes critical for intertemporal choice. Experiment 1 evaluated the acute and chronic effects of pramipexole on rats’ sensitivity to relative reinforcer delays in a concurrent-chains procedure. Contrary to the predicted effect, the drug decreased this measure, indicating the possibility of impaired stimulus control. Experiments 2 and 3 assessed the drug effect on discrimination of response-reinforcer contingencies and of reinforcer amounts, respectively, and revealed deficits in accuracy of similar magnitude across both preparations. Collectively, the results of these experiments suggest that previous findings of pramipexole-induced impulsivity and nonspecific disruption of behavior can be explained as impairments in discrimination processes required for intertemporal choice. Although the generality of the present findings may be limited to experimental settings with nonhumans, they demonstrate the utility of quantitatively modeling impulsivity.
3

Sistema integrado de alocação de esforços: tomada de decisão frente à instabilidade ambiental e sinais reprodutivos / Impulsivity and Selfishness: decision making facing environmental instability and reproductive cues

Ferreira, José Henrique Benedetti Piccoli 15 March 2013 (has links)
O presente estudo tem como objetivo investigar a integração do sistema motivacional com o sistema de adaptações responsável por definir a estratégia de ciclo de vida (CV) de um organismo. A estratégia de CV regula o modo como um organismo alocará sua energia, tempo e recursos ao longo de sua vida, influenciando o processo de desenvolvimento ontogenético e as tomadas de decisão realizadas todos os dias. Pelo íntimo relacionamento com o processo decisório, os sistemas motivacionais teriam co-evoluído com as estratégias de CV, tornando o processo de tomada de decisão mais eficiente, gerando respostas adaptativas. Esta tese é composta por 3 estudos, que investigam, através de uma estrutura experimental, a sensibilidade de nosso sistema motivacional a pistas ambientais evolutivamente relevantes e o consequente estabelecimento de padrões de respostas que estejam de acordo com as previsões da Teoria Evolucionista dos CV. Busca também investigar como as características individuais e ambientais podem influenciar a sensibilidade aos estímulos. A sensibilidade aos estímulos foi avaliada por instrumentos que medem a impulsividade através de escolhas entre recompensas de curto ou longo prazo (desconto do futuro), ou entre a possibilidade de ficar com a recompensa ou doá-la a outra pessoa (desconto social). No Estudo 1, investigamos como pistas de instabilidade ambiental, como fotos ou notícias sobre catástrofes naturais, ou notícias sobre crise econômica, influenciam a tomada de decisão frente à escolhas de desconto do futuro. Verificamos que as pessoas são sensíveis a condições de instabilidade ambiental e respondem de maneira adaptativa aos estímulos, tornando-se mais impulsivos. O status socioeconômico influenciou a sensibilidade aos estímulos. No Estudo 2, investigamos como pistas reprodutivas, como fotos sensuais, de pessoas bonitas, de pais cuidando de seus filhos e de bebês, influenciam a tomada de decisão frente a escolhas de desconto do futuro. Homens e mulheres foram sensíveis a estímulos sensuais do sexo oposto, tornando-se mais impulsivos, mas somente mulheres tiveram esta resposta frente a fotos de homens bonitos. Fotos de cuidado parental levaram mulheres a uma redução da impulsividade. A propensão dos sujeitos a relacionamentos de curto ou longo prazo e a percepção da disponibilidade de parceiros no ambiente modificaram a sensibilidade aos estímulos de origem sexual. No Estudo 3 investigamos como pistas de instabilidade ambiental influenciam a tomada de decisão frente a escolhas de desconto social. As pessoas foram sensíveis aos estímulos, apresentando comportamentos egoístas e altruístas dependendo do contexto que enfrentavam. As condições do ambiente de criação e o modo como os indivíduos formam vínculos afetivos, influenciaram a sensibilidade aos estímulos. A sensibilidade aos diferentes estímulos, levando a respostas adaptativas, como previsto pelas teorias evolucionistas, nos dão indicativos do processo de interação e possível integração entre sistemas motivacionais e sistema de adaptações responsável por definir a estratégia de CV / The present study aims to investigate the integration of the motivational system with the system of adaptations responsible for defining the strategy of life history (LH) of an organism. The LH strategy regulates how an organism allocates its energy, time and resources throughout its life, influencing the ontogenetic development process and every days decision making. Due to the close relationship with the decision-making process, the motivational systems would have co-evolved with the LH strategies, making the decision-making process more efficient, generating adaptive responses. This thesis consists of three studies, that investigates, through an experimental structure, the sensitivity of our motivational system to evolutionarily relevant environmental cues and the consequent establishment of patterns of responses consistent with the predictions of LH evolutionary theory. It also attemps to investigate how individual and environmental characteristics can influence the sensitivity to stimuli. The sensitivity to stimuli was assessed by impulsivity measuring instruments through choices between short or long term rewards (future discounting), or between the possibility to keep the reward or to give it to someone else (social discounting). In Study 1, we investigated how environmental instability cues, such as photos or news about natural disasters, or news about economic crisis, influence decision making in future discounting choices. We observed that people are sensitive to environmental instability conditions and adaptively respond to the stimulus by becoming more impulsive. The socioeconomic status influenced the stimuli sensitivity. In Study 2, we investigated how reproductive cues, such as photos of sexy people, of attractive people, of parents taking care of their children and babies, influence decision making in future discounting choices. Men and women were sensitive to sexy stimuli of the opposite sex, becoming more impulsive, but only women had this response looking pictures of attractive men. Parenting photos led women to an impulsivity reduction. The tendency of individuals to engage in short or long term romantic relationships and the perception of partner availability in the environment changed the sexual stimuli sensitivity. In Study 3 we investigated how environmental instability cues influence the decision making in social discounting choices. People were sensitive to stimuli, presenting selfish and altruistic behaviors depending on the context they faced. The childhood environment conditions and the way individuals form emotional bonds, influenced the stimuli sensitivity. The sensitivity to different stimuli, leading to adaptive responses, as predicted by evolutionary theories, give us indicatives of the interaction process and possible integration between motivational systems and adaptations systems responsible for defining LH strategy
4

Sistema integrado de alocação de esforços: tomada de decisão frente à instabilidade ambiental e sinais reprodutivos / Impulsivity and Selfishness: decision making facing environmental instability and reproductive cues

José Henrique Benedetti Piccoli Ferreira 15 March 2013 (has links)
O presente estudo tem como objetivo investigar a integração do sistema motivacional com o sistema de adaptações responsável por definir a estratégia de ciclo de vida (CV) de um organismo. A estratégia de CV regula o modo como um organismo alocará sua energia, tempo e recursos ao longo de sua vida, influenciando o processo de desenvolvimento ontogenético e as tomadas de decisão realizadas todos os dias. Pelo íntimo relacionamento com o processo decisório, os sistemas motivacionais teriam co-evoluído com as estratégias de CV, tornando o processo de tomada de decisão mais eficiente, gerando respostas adaptativas. Esta tese é composta por 3 estudos, que investigam, através de uma estrutura experimental, a sensibilidade de nosso sistema motivacional a pistas ambientais evolutivamente relevantes e o consequente estabelecimento de padrões de respostas que estejam de acordo com as previsões da Teoria Evolucionista dos CV. Busca também investigar como as características individuais e ambientais podem influenciar a sensibilidade aos estímulos. A sensibilidade aos estímulos foi avaliada por instrumentos que medem a impulsividade através de escolhas entre recompensas de curto ou longo prazo (desconto do futuro), ou entre a possibilidade de ficar com a recompensa ou doá-la a outra pessoa (desconto social). No Estudo 1, investigamos como pistas de instabilidade ambiental, como fotos ou notícias sobre catástrofes naturais, ou notícias sobre crise econômica, influenciam a tomada de decisão frente à escolhas de desconto do futuro. Verificamos que as pessoas são sensíveis a condições de instabilidade ambiental e respondem de maneira adaptativa aos estímulos, tornando-se mais impulsivos. O status socioeconômico influenciou a sensibilidade aos estímulos. No Estudo 2, investigamos como pistas reprodutivas, como fotos sensuais, de pessoas bonitas, de pais cuidando de seus filhos e de bebês, influenciam a tomada de decisão frente a escolhas de desconto do futuro. Homens e mulheres foram sensíveis a estímulos sensuais do sexo oposto, tornando-se mais impulsivos, mas somente mulheres tiveram esta resposta frente a fotos de homens bonitos. Fotos de cuidado parental levaram mulheres a uma redução da impulsividade. A propensão dos sujeitos a relacionamentos de curto ou longo prazo e a percepção da disponibilidade de parceiros no ambiente modificaram a sensibilidade aos estímulos de origem sexual. No Estudo 3 investigamos como pistas de instabilidade ambiental influenciam a tomada de decisão frente a escolhas de desconto social. As pessoas foram sensíveis aos estímulos, apresentando comportamentos egoístas e altruístas dependendo do contexto que enfrentavam. As condições do ambiente de criação e o modo como os indivíduos formam vínculos afetivos, influenciaram a sensibilidade aos estímulos. A sensibilidade aos diferentes estímulos, levando a respostas adaptativas, como previsto pelas teorias evolucionistas, nos dão indicativos do processo de interação e possível integração entre sistemas motivacionais e sistema de adaptações responsável por definir a estratégia de CV / The present study aims to investigate the integration of the motivational system with the system of adaptations responsible for defining the strategy of life history (LH) of an organism. The LH strategy regulates how an organism allocates its energy, time and resources throughout its life, influencing the ontogenetic development process and every days decision making. Due to the close relationship with the decision-making process, the motivational systems would have co-evolved with the LH strategies, making the decision-making process more efficient, generating adaptive responses. This thesis consists of three studies, that investigates, through an experimental structure, the sensitivity of our motivational system to evolutionarily relevant environmental cues and the consequent establishment of patterns of responses consistent with the predictions of LH evolutionary theory. It also attemps to investigate how individual and environmental characteristics can influence the sensitivity to stimuli. The sensitivity to stimuli was assessed by impulsivity measuring instruments through choices between short or long term rewards (future discounting), or between the possibility to keep the reward or to give it to someone else (social discounting). In Study 1, we investigated how environmental instability cues, such as photos or news about natural disasters, or news about economic crisis, influence decision making in future discounting choices. We observed that people are sensitive to environmental instability conditions and adaptively respond to the stimulus by becoming more impulsive. The socioeconomic status influenced the stimuli sensitivity. In Study 2, we investigated how reproductive cues, such as photos of sexy people, of attractive people, of parents taking care of their children and babies, influence decision making in future discounting choices. Men and women were sensitive to sexy stimuli of the opposite sex, becoming more impulsive, but only women had this response looking pictures of attractive men. Parenting photos led women to an impulsivity reduction. The tendency of individuals to engage in short or long term romantic relationships and the perception of partner availability in the environment changed the sexual stimuli sensitivity. In Study 3 we investigated how environmental instability cues influence the decision making in social discounting choices. People were sensitive to stimuli, presenting selfish and altruistic behaviors depending on the context they faced. The childhood environment conditions and the way individuals form emotional bonds, influenced the stimuli sensitivity. The sensitivity to different stimuli, leading to adaptive responses, as predicted by evolutionary theories, give us indicatives of the interaction process and possible integration between motivational systems and adaptations systems responsible for defining LH strategy
5

De la communication acoustique au sein du groupe : contraintes et mécanismes / Acoustic communication within a group : constrains and mechanisms

Brunel, Odette 10 December 2012 (has links)
Chez les insectes où les males chantent en chorus, l’interférence locale de signaux impose des contraintes majeures à des femelles qui doivent évaluer les mâles individuellement. Les mâles subis des difficultés pour évaluer la compétitivité de leurs voisins et pour montrer clairement aux femelles les caractéristiques de leurs propres chants. J’ai analysé différents aspects de cette problématique chez deux espèces acoustiques : chez la sauterelle ephippiger et une pyrale nocturne qui émettent leurs signaux au sein de regroupements. Nos expériences ont mis en évidence certains mécanismes comportementaux permettant aux femelles de localiser les meuliers males et d’autres permettant aux mâles de se communiquer efficacement et percevoir leur environnement acoustique. / In acoustic insects where males sing in choruses, local signal interference may present major difficulties for females evaluating and individual males. Males too may be prevented from assessing the competitivity of their neighbors as well as from advertising the characteristics of their own signals to females in a clear manner. Moreover, the background noise from local signals may prevent both sexes from perceiving other sounds in the environment, e.g. predator cues. I studied these problems at several levels in two acoustic insect species: in which males broadcast their advertisement songs while remaining in dense clusters. The experiments revealed behavioral mechanisms with which females can identify favored males and others with which males can communicate effectively.
6

Autoeficácia, lócus de controle da saúde, religiosidade e não-aderência medicamentosa no pós-transplante renal

Silva, Andresa Nascimento da 04 August 2015 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-04-20T17:36:50Z No. of bitstreams: 1 andresanascimentodasilva.pdf: 752132 bytes, checksum: d67a82bd728f0577d6c96eecf5cef053 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-04-24T03:02:50Z (GMT) No. of bitstreams: 1 andresanascimentodasilva.pdf: 752132 bytes, checksum: d67a82bd728f0577d6c96eecf5cef053 (MD5) / Made available in DSpace on 2016-04-24T03:02:50Z (GMT). No. of bitstreams: 1 andresanascimentodasilva.pdf: 752132 bytes, checksum: d67a82bd728f0577d6c96eecf5cef053 (MD5) Previous issue date: 2015-08-04 / A aderência aos imunossupressores constitui um elemento essencial para os resultados do transplante renal e tem sido alvo crescente de estudos devido à sua relevância para o tratamento. Pode ser definida como o grau de concordância entre o comportamento de uma pessoa em relação às orientações do médico ou de outro profissional da equipe de saúde. Recebe influência de questões socioeconômicas, do sistema e profissionais de saúde, fatores relacionados às condições de saúde, à terapia e ao paciente. Dentre estes, os fatores relacionados ao paciente são pouco estudados. Este estudo teve como objetivo geral avaliar a relação entre alguns destes fatores individuais do paciente, como as crenças de autoeficácia, lócus de controle da saúde (LCS) e religiosidade e o comportamento de não-aderência aos imunossupressores em pacientes transplantados renais. Foi desenvolvido um estudo de corte transversal em que foram avaliados 88 pacientes acompanhados no ambulatório de pós-transplante do Hospital Universitário de Juiz de Fora. O diagnóstico de não-aderência foi realizado pelo método da triangulação, utilizando a Escala Basel para Avaliação de Aderência a Medicamentos Imunossupressores (BAASIS), opinião dos profissionais e dosagem do nível sanguíneo dos imunossupressores. As crenças de autoeficácia, lócus de controle da saúde e religiosidade foram avaliadas pelas escalas de Autoeficácia Geral Percebida, Multidimensional de Lócus de Controle da Saúde e do Índice de Religiosidade da Universidade de Duke (DUREL), respectivamente. Os pacientes aderentes e não aderentes foram comparados pelos testes do qui-quadrado, t de Student e correlação de Spearman. A maioria dos pacientes era do sexo masculino (63%), recebeu enxerto renal de doador vivo (96%), tinha média de idade de 47,2±12,9 anos e tempo mediano pós-transplante de 108,71 (49,0-266,0) meses. Encontramos uma elevada prevalência de não-aderência, de 70,5%. Observamos uma maior pontuação de autoeficácia nos pacientes aderentes em relação aos não-aderentes, 45,14+4,9 vs. 38,32+8,6 (p<0,001), respectivamente. As dimensões do LCS não foram diferentes entre os grupos. Em relação à religiosidade, apenas a dimensão religiosidade intrínseca, que acessa o nível pessoal de envolvimento ou motivação religiosa, apresentou maior pontuação nos pacientes aderentes em relação aos não-aderentes (14,0+1,6 vs 12,8+2,5; p=0,016]. Não houve correlação significativa entre autoeficácia e os níveis de religiosidade, avaliados através da correlação de Spearman. Considerando os nossos resultados, sugere-se que os profissionais adotem uma visão holística em relação ao paciente. Aspectos, tais como a religiosidade e as crenças de autoeficácia, devem ser consideradas quando se traçarem estratégias para alcançar uma melhor autogestão e maior aderência aos imunossupressores. / The adherence to immunosuppressants is an essential element for the results of renal transplantation and has been a growing target of studies because of its relevance for the treatment. It can be defined as the degree of agreement between the behavior of a person in relation to the guidelines of the physician or other health care professional. It receives influence from socioeconomic issues, health care system and professionals, factors related to the disease, to its therapy, and to the patient. Among these, the patient-related factors are poorly studied. This study had, as main objective, to evaluate the relationship between some of these individual factors, such as self-efficacy beliefs, health locus of control (HLC) and religiosity and immunosuppressants non-adherence behavior in kidney transplant patients. A cross-sectional study evaluated 88 patients treated at the post-transplant clinic of the School Hospital of Federal University of Juiz de Fora. The diagnosis of non-adherence was carried out by the triangulation method, using the Basel Assessment of Adherence to Immunosuppressive Medications Scale (BAASIS), collateral report and immunosuppressive blood levels. Self-efficacy, HLC, and religiosity were evaluated applying the General Perceived Self-Efficacy Scale, Multidimensional Health Locus of Control Scale and the Portuguese version of Duke University Religion Index (DUREL), respectively. Adherent and non-adherent patients were compared using the chi-square, Student t, and Spearman´s correlation tests. Most patients were male (63%), received kidney graft from a living donor (96%) had a mean age of 47.2 ± 12.9 years and median time post-transplant of 108.71 (49.0 to 266.0) months. We found a high prevalence of non-adherence, 70.5%. We observed a higher score of self-efficacy in adherents compared to non-adherents, (45.14+4.9 vs. 38.32+8.6; p<0.001), respectively. The HLC dimensions were not different between groups. Concerning to religion, the dimension intrinsic religiosity, which accesses the personal level of involvement or religious motivation, showed a higher scores in adherent patients compared to non-adherents (14.0+1.6 vs 12.8+2.5; p=0.016). Considering our results, it is suggested that professionals have a holistic vision of the patient. These aspects, such as religiosity and self-efficacy believes , should be taken into account when designing strategies for a better self-management and higher adherence to immunosuppressives.

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