923 resultados para Biology, Biostatistics|Psychology, Behavioral Sciences|Health Sciences, Epidemiology
Resumo:
Many twin studies have identified sex differences in the influence of genetic and environmental factors on smoking behaviors. We explore the evidence for sex differences for smoking initiation and cigarette consumption in a sample of Australian twin families, and extend these models to incorporate sex differences in linkage analyses for these traits. We further examine the impact of including or excluding non-smokers in genetic analyses of tobacco consumption. Accounting for sex differences improved linkage results in some instances. We identified one region suggestive of linkage on chromosome 11p12. This locus, as well as another region identified on chromosome 6p12, replicates regions identified in previous studies.
Resumo:
Chimpanzees (Pan troglodytes) and young children (Homo sapiens) have difficulty with double invisible displacements in which an object is hidden in two nonadjacent boxes in a linear array. Experiment 1 eliminated the possibility that chimpanzees' previous poor performance was due to the hiding direction of the displacement device. As in Call (2001), subjects failed double nonadjacent displacements, showing a tendency to select adjacent boxes. In Experiments 2 and 3, chimpanzees and 24-month-old children were tested on a new adaptation of the task in which four hiding boxes were presented in a diamond-shaped array on a vertical plane. Both species performed above chance on double invisible displacements using this format, suggesting that previous poor performance was due to a response bias or inhibition problem rather than a fundamental limitation in representational capacity.
Resumo:
Recent research on causal learning found (a) that causal judgments reflect either the current predictive value of a conditional stimulus (CS) or an integration across the experimental contingencies used in the entire experiment and (b) that postexperimental judgments, rather than the CS's current predictive value, are likely to reflect this integration. In the current study, the authors examined whether verbal valence ratings were subject to similar integration. Assessments of stimulus valence and contingencies responded similarly to variations of reporting requirements, contingency reversal, and extinction, reflecting either current or integrated values. However, affective learning required more trials to reflect a contingency change than did contingency judgments. The integration of valence assessments across training and the fact that affective learning is slow to reflect contingency changes can provide an alternative interpretation for researchers' previous failures to find an effect of extinction training on verbal reports of CS valence.
Resumo:
Transient prenatal vitamin D deficiency produces hyperlocomotion in the adult rat. The aim of this study was to examine the effects of acute restraint on the behaviour of DVD and control rats in the open field. Rats were conceived and born to developmentally vitamin D (DVD) deficient or replete (control) dams and, at 8 weeks of age, were monitored for 30 min in an open field using automated video tracking software. Half of the rats were restrained within a towel for 5 min immediately before the open field test. The remainder received minimal handling prior to the open field test. Repeating previous findings, DVD deficient animals had enhanced locomotion during the first 10 min of the open field test compared to control rats. By contrast, there were no differences in locomotor activity after acute restraint stress. The time rats spent in the corners and side of the open field was affected by prenatal diet. DVD rats spent less time in the corners and more time in the side than control rats across the whole 30 min test. This difference was not seen in rats with acute restraint stress. The time spent in the centre was not altered by prenatal diet or acute restraint. Thus, transient prenatal vitamin D deficiency induces a transient spontaneous hyperlocomotion in adulthood that is modulated by acute restraint stress. (c) 2006 Elsevier B.V. All rights reserved.
Resumo:
A cluster, stratified randomized design was used to evaluate the impact of universal, indicated, and combined universal plus indicated cognitive-behavioral approaches to the prevention of depression among 13- to 15-year-olds initially reporting elevated symptoms of depression. None of the intervention approaches differed significantly from a no-intervention condition or from each other on changes in depressive symptoms, anxiety, externalizing problems, coping skills, and social adjustment. All high-symptom students, irrespective of condition, showed a significant decline in depressive symptoms and improvement in emotional well-being over time although they still demonstrated elevated levels of psychopathology compared with the general population of peers at 12-month follow-up. There were also no significant intervention effects for the universal intervention in comparison with no intervention for the total sample of students in those conditions.
Resumo:
Este estudo teve como objetivo principal analisar a relação entre a Liderança Transformacional, a Conversão do Conhecimento e a Eficácia Organizacional. Foram considerados como pressupostos teóricos conceitos consolidados sobre os temas desta relação, além de recentes pesquisas já realizadas em outros países e contextos organizacionais. Com base nisto identificou-se potencial estudo de um modelo que relacionasse estes três conceitos. Para tal considera-se que as organizações que buscam atingir Vantagem Competitiva e incorporam a Knowledge-Based View possam conquistar diferenciação frente a seus concorrentes. Nesse contexto o conhecimento ganha maior destaque e papel protagonista nestas organizações. Dessa forma criar conhecimento através de seus colaboradores, passa a ser um dos desafios dessas organizações ao passo que sugere melhoria de seus indicadores Econômicos, Sociais, Sistêmicos e Políticos, o que se define por Eficácia Organizacional. Portanto os modos de conversão do conhecimento nas organizações, demonstram relevância, uma vez que se cria e se converte conhecimentos através da interação entre o conhecimento existente de seus colaboradores. Essa conversão do conhecimento ou modelo SECI possui quatro modos que são a Socialização, Externalização, Combinação e Internalização. Nessa perspectiva a liderança nas organizações apresenta-se como um elemento capaz de influenciar seus colaboradores, propiciando maior dinâmica ao modelo SECI de conversão do conhecimento. Se identifica então na liderança do tipo Transformacional, características que possam influenciar colaboradores e entende-se que esta relação entre a Liderança Transformacional e a Conversão do Conhecimento possa ter influência positiva nos indicadores da Eficácia Organizacional. Dessa forma esta pesquisa buscou analisar um modelo que explorasse essa relação entre a liderança do tipo Transformacional, a Conversão do Conhecimento (SECI) e a Eficácia Organizacional. Esta pesquisa teve o caráter quantitativo com coleta de dados através do método survey, obtendo um total de 230 respondentes válidos de diferentes organizações. O instrumento de coleta de dados foi composto por afirmativas relativas ao modelo de relação pesquisado com um total de 44 itens. O perfil de respondentes concentrou-se entre 30 e 39 anos de idade, com a predominância de organizações privadas e de departamentos de TI/Telecom, Docência e Recursos Humanos respectivamente. O tratamento dos dados foi através da Análise Fatorial Exploratória e Modelagem de Equações Estruturais via Partial Least Square Path Modeling (PLS-PM). Como resultado da análise desta pesquisa, as hipóteses puderam ser confirmadas, concluindo que a Liderança Transformacional apresenta influência positiva nos modos de Conversão do Conhecimento e que; a Conversão do Conhecimento influencia positivamente na Eficácia Organizacional. Ainda, concluiu-se que a percepção entre os respondentes não apresenta resultado diferente sobre o modelo desta pesquisa entre quem possui ou não função de liderança.
Resumo:
In this thesis, I contribute to the expansion of lesbian, gay, bisexual, trans and queer (LGBTQ) psychology by examining chronic illness within non-heterosexual contexts. Chronic illness, beyond the confines of HIV/AIDS, has been a neglected topic in LGBTQ psychology and sexual identity is often overlooked within health psychology. When the health of lesbian, gay and bisexual (LGB) people has been considered there has been an over-reliance on quantitative methods and comparative approaches which seek to compare LGB people?s health to their heterosexual counterparts. In contrast, I adopt a critical perspective and qualitative methods to explore LGBTQ health. My research brings together ideas from LGBTQ psychology and critical health psychology to explore non-heterosexuals? experiences of chronic illness and the discursive contexts within which LGB people live with chronic health conditions. I also highlight the heteronormativity which pervades academic health psychology as well as the „lay? health literature. The research presented in this thesis draws on three different sources of qualitative data: a qualitative online questionnaire (n=190), an online discussion within a newsgroup for people with diabetes, and semi-structured interviews with 20 LGB people with diabetes. These data are analysed using critical realist forms of thematic analysis and discourse analysis. In the first analytic chapter (Chapter 3), I report the perspectives of LGB people living with many different chronic illnesses and how they felt their sexuality shapes their experiences of illness. In Chapter 4, I examine heterosexism within an online discussion and consider the ways in which sexuality is constructed as (ir)relevant to a diabetes support forum. In Chapter 5, I analyse LGB people?s talk about the support family and partners provide in relation to their diabetes and how they negotiate wider discourses of gender, sexuality and individualism. In Chapter 6 I explore how diabetes intersects with gay and bisexual men?s sex lives. In the concluding chapter, I discuss the contributions of my research for a critical LGBTQ health psychology and identify some possible areas for future research.
Resumo:
The moral foundation of capitalism should be reconsidered. Modern capitalism is disembedded from the social and cultural norms of society and produced a deep financial, ecological and social crisis. Competitiveness is the prevailing ideology of today’s business and economic policy. Companies, regions, and national economies seek to improve their productivity and gain competitive advantage. But these efforts often produce negative effects on various stakeholders at home and abroad. Competitiveness involves self-interest and aggressivity and produces monetary results at the expense of nature, society and future generations The collaborative enterprise framework promotes a view in which economic agents care about others and themselves and aim to create values for all the participants in their business ecosystems. Their criterion of success is mutually satisfying relationships with the stakeholders. New results of positive psychology and the Homo reciprocans model of behavioral sciences support this approach. The economic teachings of world religions challenge the way capitalism is functioning, and their corresponding perspectives are worthy of consideration. They represent life-serving modes of economizing which can assure the livelihood of human communities and the sustainability of natural ecosystems. Ethics and the future of capitalism are strongly connected. If we want to sustain capitalism for a long time we have to create a less violent, more caring form of it.
Resumo:
The aorta has been viewed as a passive distribution manifold for blood whose elasticity allows it to store blood during cardiac ejection (systole), and release it during relaxation (diastole). This capacitance, or compliance, lowers peak cardiac work input and maintains peripheral sanguine irrigation throughout the cardiac cycle. The compliance of the human and canine circulatory systems have been described either as constant throughout the cycle (Toy et al. 1985) or as some inverse function of pressure (Li et al. 1990, Cappelo et al. 1995). This work shows that a compliance value that is higher during systole than diastole (equivalent to a direct function of pressure) leads to a reduction in the energetic input to the cardiovascular system (CV), even when accounting for the energy required to change compliance. This conclusion is obtained numerically, based on a 3-element lumped-parameter model of the CV, then demonstrated in a physical model built for the purpose. It is then shown, based on the numerical and physical models, on analytical considerations of elastic tubes, and on the analysis of arterial volume as a function of pressure measured in vivo (Armentano et al. 1995), that the mechanical effects of a presupposed arterial contraction are consistent with those of energetically beneficial changes in compliance during the cardiac cycle. Although the amount of energy potentially saved with rhythmically contracting arteries is small (mean 0.55% for the cases studied) the importance of the phenomenon lies in its possible relation to another function of the arterial smooth muscle (ASM): synthesis of wall matrix macromolecules. It is speculated that a reduction in the rate of collagen synthesis by the ASM is implicated in the formation of arteriosclerosis. ^