GABAergic mediation of stress-induced secretion of corticosterone and oxytocin, but not prolactin, by the hypothalamic paraventricular nucleus

The hypothalamus-pituitary-adrenal axis (HPA) participates in mediating the response to stressful stimuli. Within the HPA, neurons in the medial parvocellular region of paraventricular nucleus (PVN) of the hypothalamus integrate excitatory and inhibitory signals triggering secretion of corticotropin-releasing hormone (CRH), the main secretagogue of adrenocorticotropic hormone (ACTH). Stressful situations alter CRH secretion as well as other hormones, including prolactin and oxytocin. Most inputs to the PVN are of local origin, half of which are GABAergic neurons, and both GABA-A and GABA-B receptors are present in the PVN. The objective of the present study was to investigate the role of GABA-A and GABA-B receptors in the PVN`s control of stress-induced corticosterone, oxytocin and prolactin secretion. Rats Were microinjected with saline or different doses (0.5, 5 and 50 pmol) of GABA-A (bicuculine) or GABA-B (phaclofen) antagonists in the PVN. Ten minutes later, they were subjected to a stressor (ether inhalation) and blood samples were collected 30 min before and 10, 30, 60, 90 and 120 min after the stressful stimulus to measure hormone levels by radioimmunoassay. Our results indicate that GABA acts in the PVN to inhibit stress-induced corticosterone secretion via both its receptor subtypes, especially GABA-B. In contrast, GABA in the PVN stimulates oxytocin secretion through GABA-B receptors and does not alter prolactin secretion. (C) 2008 Elsevier Inc. All rights reserved.

Read the whole thing: Journalism, weblogs and the re-mediation of the war in Iraq

This paper examines a particular form of online activity-weblogging, and how it has allowed for specific new forms of popular political communication in the context of the Second Gulf War. After describing the basics of weblogging, the paper discusses Western media coverage of the war and then shows how 'warbloggers' positioned themselves vis-à-vis media coverage and propaganda, creating commentaries that frequently combined media and political criticism. While bloggers of every political hue offered a range of perspectives and personal styles, some general tendencies are evident in warblogging discourse. The piece ends by questioning the significance of warblogging in terms of its potential contribution to democratic communication.

Ambiguidade e consequências futuras doscomportamentos éticos: estudo intercultural

Os comportamentos de ética empresarial têm sido questionados, com os recentes escândalos econômico-financeiros e as práticas de empresas e trabalhadores. Neste estudo, baseado em dados recolhidos por questionário, comparamos as perceções de ética de estudantes portugueses (N=109) e brasileiros (N=190) de Administração, expostos a um conjunto de cenários de ética e aceitabilidade de práticas comerciais, diante de duas dimensões culturais: a tolerância à ambiguidade e a antecipação das consequências futuras. Os resultados mostram diferenças significativas entre os brasileiros e os portugueses nas três dimensões, sendo os brasileiros mais tolerantes à ambiguidade e mais conscientes das consequências futuras dos seus atos, mas com maior propensão a comportamentos menos éticos. A perspetiva de ganhos mais imediatos parece sobrepor-se à incerteza e aos riscos a médio e longo prazos que a prática de comportamentos menos éticos pode acarretar. Concluímos com uma discussão ampla e pistas para investigação futura.

Ajustamento intercultural de executivos japoneses expatriados no Brasil: um estudo empírico

O ajustamento intercultural tem sido considerado fator determinante do sucesso em missões internacionais e o conceito-chave do modelo de ajustamento internacional de Black, Mendenhall e Oddou (1991a). O objetivo deste artigo é analisar o ajustamento intercultural de executivos japoneses expatriados. Realizou-se uma pesquisa qualitativa com 37 executivos japoneses expatriados, em 21 empresas de diversos setores no Brasil. Apesar de a literatura considerar os expatriados japoneses exemplos de sucesso, devido às baixas taxas de falhas em missões internacionais, os resultados mostram que eles não se ajustam, pois recebem pouco ou nenhum treinamento intercultural, permanecem distantes dos locais, além de acumularem estresse no trabalho e não poderem falhar. Este artigo contribui para o melhor entendimento do construto do ajustamento intercultural e reforça a necessidade de rever o modelo de Black, Mendenhall e Oddou (1991a) para outras nacionalidades.

Analysis of mediation and reciprocal effects of changes in weight, self-esteem, and exercise in a behavioral weight loss treatment

Improving the treatment of obesity remains a critical challenge. Several health behaviour change models, often based on a social-cognitive framework, have been used to design weight management interventions (Baranowski et al., 2003). However, most interventions have only produced modest weight reductions (Wadden et al., 2002) and socialcognitive variables have shown limited power to predict weight outcomes (Palmeira et al., 2007). Other predictors, and possibl alte nati e e planatory models, are needed to better understand the mechanisms by which weight loss and other obesity treatment-outcomes are brought about (Baranowski, 2006). Self-esteem is one of these possible mechanisms, because is commonly reported to change during the treatment, although these changes are not necessarily associated with weight loss (Blaine et al., 2007; Maciejewski et al., 2005). This possibility should be more evident if the program integrates regular exercise, as it promotes improvements in subjective well-being (Biddle & Mutrie, 2001), with possible influences on long-term behavioral adherence (e.g. diet, exercise). Following the reciprocal effects model tenets (Marsh & Craven, 2006), we expect that the influences between changes in weight, selfesteem and exercise to be reciprocal and might present one of the mechanisms by which obesity treatments can be improved.

Relação intercultural entre Cabo Verde e França

Orientador: Mestre Alberto Couto

In permanent transit: discourses and maps of the intercultural experience

Instituto Politécnico do Porto. Instituto Superior de Contabilidade e Administração do Porto