The main objective of this thesis was to develop and empirically test a novel analytical framework for occupational mental health: the Healthy Learning Organizations model. One of the central premises of this model is that the organization is an important analytical component to the explanation of the ecology of occupational mental health. More specifically, the nature of the organizational learning process underwent by organizations constitutes a determining source of organizational variability in the distribution of psychosocial risk factors and mental health outcomes. The predictive power of the model was evaluated through the examination of the organizational reality of senior executives from the federal public service of Canada using a mixed methods approach. The thesis is organized around four scientific articles. The first article provides a critical synthesis of organizational learning literature and draws on the sociological theory on agency and structure to formulate a set of theoretical propositions tackling current challenges on the dimensionality of organizational learning. The second article operationalizes these propositions with a psychometric evaluation of the Organizational Learning Dimensions Inventory. Findings supported the validity and fidelity of the instrument, as well as the relevance of its utilization as a subjective (i.e., individual scores) and collective measure (i.e., scores aggregated at the organizational unit) of organizational learning. The Healthy Learning Organizations model bridges this definition of organizational learning to dominant conceptualizations on occupational stress. In the third article, multilevel analysis demonstrates that the subjective measure of organizational learning is a protective factor in association to mental health outcomes, independent of the relative contribution of psychosocial work factors and the sociodemographic profile of senior executives. Semi-structured interviews offer additional insights for such a protective association. Lastly, latent class analysis in the fourth article shows that the Healthy Learning Organizations model supports a typology of organizational contexts associated to differential risk exposures for occupational mental health. Overall, the Healthy Learning Organizations model emphasizes the need to increase current understanding about organizations and their internal dynamics as social contexts for population health among workers.

As nanotecnologias são um conjunto multidisciplinar de técnicas que manipulam a matéria em escala nanométrica, mais precisamente partículas abaixo de 100 nanômetros, cujas características por conta do tamanho diminuto são essencialmente diferentes daquelas encontradas no material em sua forma macro. Em função destas novas propriedades dos materiais, existem lacunas de conhecimento relativas aos efeitos destas partículas sobre o organismo humano e sobre o meio ambiente. Embora ainda sejam consideradas tecnologias emergentes, seu crescimento é cada vez mais acelerado e o número de produtos que fazem uso de nanotecnologia em alguma fase de sua produção continua crescendo, bem como o número de pesquisadores envolvidos com o tema. Considerando este cenário e a literatura pertinente, este trabalho objetivou desenvolver uma sistemática de ações de segurança e saúde no trabalho (SST) para laboratórios de pesquisa com atividades de nanotecnologia. Esta sistemática é fundamentada na estrutura das diretrizes para um sistema de gestão de segurança e saúde no trabalho proposto pela Organização Internacional do Trabalho (OIT). A esta base foram agregadas diversas recomendações nanoespecíficas, sendo desta maneira consolidada a Sistemática de SST para Laboratórios com Nanotecnologia (S-SST/LabNano). Além da comparação desta sistemática com outras apresentadas por outros autores, uma pesquisa survey foi realizada, com o propósito de obter um retrato da SST em laboratórios com atividades de nanotecnologia no Brasil. De forma complementar, objetivando a adequação prática, a S-SST/LabNano foi avaliada em relação a realidade de SST encontrada em laboratório. O resultado final da tese, além da sistemática em si (S-SST/LabNano), almeja oferecer elementos de reflexão que possam auxiliar a gestão e o controle de riscos ocupacionais associados às nanotecnologias. / Nanotechnology is a multidisciplinary set of techniques that manipulates material at nanoscale, precisely particles below 100 nanometers whose characteristics, due to the small size, are essentially different from those found in material while in macro format. In the light of these new properties of materials, there are knowledge gaps regarding the effects of these particles on the human body and the environment. Although still considered emerging technologies, their growth is increasingly accelerated and the number of products that use nanotechnology in some stage of its production continues to grow, as well as the number of researchers involved with the topic. Given this scenario and its relevant literature, this study aimed to develop a proposed methodology of actions in occupational safety and health (OSH) to research laboratories with nanotechnology activities. This methodology is based on the structure of the International Labour Organization (ILO) guidelines for a management system in safety and health at work. Several specific recommendations were added, named Participatory Nano Safety Lab (PNSL). Besides the confrontation of this proposal with other authors, a research survey was conducted with the purpose to obtain a general picture of the OSH in laboratories with nanotechnology activities in Brazil. In a complementary way, aiming a practical suitability, the PNSL was confronted with the reality of OSH found in laboratory. The final result of this thesis, besides the methodology itself (PNSL), aims to provide elements of reflection that may assist management and occupational risk control associated to nanotechnology.

Exercise induces a residual post-exercise increase in the core temperature threshold at which cutaneous vasodilation and sweating begins. The hypothesis that exercise intensity causes a parallel increase in the post-exercise onset threshold for cutaneous vasodilation mediated by an attenuation of active vasodilator activity, was tested in nine subjects. The effect of exercise intensity on the esophageal temperature threshold for the onset of sweating was also evaluated. Esophageal temperature was monitored as an index of core temperature while sweat rate was measured using a ventilated capsule placed on the upper back. Increases in forearm skin blood flow and mean arterial blood pressure were measured and used to calculate cutaneous vascular conductance at two superficial sites, one with intact alpha-adrenergic vasoconstrictor activity and one infused with bretylium tosylate. On four separate days, subjects either remained seated for 35 min or performed 15 min treadmill running at 55, 70 or 85% VO2max followed by 20 min seated recovery. A liquid conditioned suit was used to increase mean skin temperature until cutaneous vasodilation and sweating occurred. It is concluded that intensity of exercise has a prolonged residual effect on the post-exercise vasomotor and sudomotor response by increasing the esophageal temperature at which onset of vasodilation and sweating occurs. Furthermore, the post-exercise increase in onset threshold for vasodilation is likely caused by an attenuation of active vasodilator activity modulated by baroreceptor reflexes in response to post-exercise hypotension.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.