931 resultados para Exchanges


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Background and aims: Virgin olive oil (VOO) and nuts are basic components of the Mediterranean diet, a heart-healthy dietary pattern. Nuts have well known cholesterol lowering effects, while evidence is unclear for VOO. We designed a study in hypercholesterolemic patients to assess the effects on serum lipids and other intermediate markers of cardiovascular risk of replacing 40% of the fat in the background diet with VOO, walnuts or almonds. Methods and Results: After a 4 week run-in period with a healthy diet, eligible candidates were randomized into three diet sequences in a crossover design, with a common background diet enriched with VOO, walnuts or almonds, lasting 4 weeks each. Outcomes were changes of serum lipids and oxidation and inflammation markers, measured by standard methods. Plasma fatty acids were determined by gas chromatography to assess compliance. In 18 participants completing the study (9 women, mean age 56 y, BMI 25.7 kg/m(2)), LDL-cholesterol was reduced from baseline by 7.3%, 10.8% and 13.4% after the VOO, walnut and almond diets, respectively (P = 0.001, Friedman test). Total cholesterol and LDL/HDL ratios decreased in parallel. LDL-cholesterol decreases were greater than predicted from dietary fatty acid and cholesterol exchanges among diets. No changes of other lipid fractions, oxidation analytes or inflammatory biomarkers were observed. Plasma fatty acid changes after each diet sequence supported good compliance.

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Cloud streets are common feature in the Amazon Basin. They form from the combination of the vertical trade wind stress and moist convection. Here, satellite imagery, data collected during the COBRA-PARA (Caxiuan Observations in the Biosphere, River and Atmosphere of Para) field campaign, and high resolution modeling are used to understand the streets` formation and behavior. The observations show that the streets have an aspect ratio of about 3.5 and they reach their maximum activity around 15:00 UTC when the wind shear is weaker, and the convective boundary layer reaches its maximum height. The simulations reveal that the cloud streets onset is caused by the local circulations and convection produced at the interfaces between forest and rivers of the Amazon. The satellite data and modeling show that the large rivers anchor the cloud streets producing a quasi-stationary horizontal pattern. The streets are associated with horizontal roll vortices parallel to the mean flow that organizes the turbulence causing advection of latent heat flux towards the upward branches. The streets have multiple warm plumes that promote a connection between the rolls. These spatial patterns allow fundamental insights on the interpretation of the Amazon exchanges between surface and atmosphere with important consequences for the climate change understanding.

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Resonant interactions among equatorial waves in the presence of a diurnally varying heat source are studied in the context of the diabatic version of the equatorial beta-plane primitive equations for a motionless, hydrostatic, horizontally homogeneous and stably stratified background atmosphere. The heat source is assumed to be periodic in time and of small amplitude [i.e., O(epsilon)] and is prescribed to roughly represent the typical heating associated with deep convection in the tropical atmosphere. In this context, using the asymptotic method of multiple time scales, the free linear Rossby, Kelvin, mixed Rossby-gravity, and inertio-gravity waves, as well as their vertical structures, are obtained as leading-order solutions. These waves are shown to interact resonantly in a triad configuration at the O(e) approximation, and the dynamics of these interactions have been studied in the presence of the forcing. It is shown that for the planetary-scale wave resonant triads composed of two first baroclinic equatorially trapped waves and one barotropic Rossby mode, the spectrum of the thermal forcing is such that only one of the triad components is resonant with the heat source. As a result, to illustrate the role of the diurnal forcing in these interactions in a simplified fashion, two kinds of triads have been analyzed. The first one refers to triads composed of a k = 0 first baroclinic geostrophic mode, which is resonant with the stationary component of the diurnal heat source, and two dispersive modes, namely, a mixed Rossby-gravity wave and a barotropic Rossby mode. The other class corresponds to triads composed of two first baroclinic inertio-gravity waves in which the highest-frequency wave resonates with a transient harmonic of the forcing. The integration of the asymptotic reduced equations for these selected resonant triads shows that the stationary component of the diurnal heat source acts as an ""accelerator"" for the energy exchanges between the two dispersive waves through the excitation of the catalyst geostrophic mode. On the other hand, since in the second class of triads the mode that resonates with the forcing is the most energetically active member because of the energy constraints imposed by the triad dynamics, the results show that the convective forcing in this case is responsible for a longer time scale modulation in the resonant interactions, generating a period doubling in the energy exchanges. The results suggest that the diurnal variation of tropical convection might play an important role in generating low-frequency fluctuations in the atmospheric circulation through resonant nonlinear interactions.

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Weakly nonlinear interactions among equatorial waves have been explored in this paper using the adiabatic version of the equatorial beta-plane primitive equations in isobaric coordinates. Assuming rigid lid vertical boundary conditions, the conditions imposed at the surface and at the top of the troposphere were expanded in a Taylor series around two isobaric surfaces in an approach similar to that used in the theory of surface-gravity waves in deep water and capillary-gravity waves. By adopting the asymptotic method of multiple time scales, the equatorial Rossby, mixed Rossby-gravity, inertio-gravity, and Kelvin waves, as well as their vertical structures, were obtained as leading-order solutions. These waves were shown to interact resonantly in a triad configuration at the O(epsilon) approximation. The resonant triads whose wave components satisfy a resonance condition for their vertical structures were found to have the most significant interactions, although this condition is not excluding, unlike the resonant conditions for the zonal wavenumbers and meridional modes. Thus, the analysis has focused on such resonant triads. In general, it was found that for these resonant triads satisfying the resonance condition in the vertical direction, the wave with the highest absolute frequency always acts as an energy source (or sink) for the remaining triad components, as usually occurs in several other physical problems in fluid dynamics. In addition, the zonally symmetric geostrophic modes act as catalyst modes for the energy exchanges between two dispersive waves in a resonant triad. The integration of the reduced asymptotic equations for a single resonant triad shows that, for the initial mode amplitudes characterizing realistic magnitudes of atmospheric flow perturbations, the modes in general exchange energy on low-frequency (intraseasonal and/or even longer) time scales, with the interaction period being dependent upon the initial mode amplitudes. Potential future applications of the present theory to the real atmosphere with the inclusion of diabatic forcing, dissipation, and a more realistic background state are also discussed.

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Previous works suggested that Pleurostima purpurea (Velloziaceae-Barbacenioideae) shows a remarkable capacity to endure desiccation of its vegetative tissues. P. purpurea occurs in monocotyledons mats on soil islands in the Pao de Acucar (Sugar Loaf) one of the most recognizable rock outcrops of the world, in Rio de Janeiro, southeastern Brazil. Mats of P. purpurea occur in cliffs by the sea some meters above the tidal zone. Although living in rock outcrops almost devoid of any soil cover, P. purpurea seems to occur preferably on less exposed rock faces and slightly shady sites. Usually, less extreme adaptations to drought would be expected in plants with the habitat preference of P. purpurea. Relying on this observation, we argue if a combination of different strategies of dealing with low water availability can be found in P. purpurea as on other desiccation tolerant angiosperms. This study aims to examine the occurrence of desiccation tolerant behavior in P. purpurea together with the expression of drought avoidance mechanisms during dehydration progression. For this, it was analyzed the gas exchanges, leaf pigments and relative leaf water content during desiccation and rehydration of cultivated mature individuals. P. purpurea behaved like typical drought avoiders under moderated drought condition with stomatal closure occurring around a relative leaf water content up to 90%. During this process, it was observed a delay in the leaf relative water content (RWC(leaf)) decrease comparing to the plant-soil relative water content (RWC(plant-soil)). As soil dehydration worsened, gas exchanges restrictions progressed until a lack of activity which characterizes anabiosis. The loss of chlorophyll occurs before the end of total dehydration, characterizing the presence of poikilochlorophylly. The chlorophyll degradation follows the RWC(leaf) decrease, which achieved the minimum average value of 17% without incurring in leaf abscission. The chlorophyll re-synthesis seems to start well after the full rehydration of the leaf. During all of this process, carotenoid content remained stable. These results are coherent with a combination of drought avoidance and desiccation tolerance in P. purpurea which seems to be coherent with the amplitude of water availability in the rock outcrop habitat where it occurs, suggesting that the periods of water availability are sufficiently long for the success of the costly desiccation tolerant behavior but too short to make a typical drought avoider species win the competition for exploring the rock outcrop substrate where P. purpurea occurs.

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We evaluate the non-resonant decay amplitude of the process B(+/-) -> K(+/-)pi(+)pi(-) using an approach based on final state hadronic interactions described in terms of meson exchanges. We conclude that this mechanism generates inhomogeneities in the Dalitz plot of the B decay. (C) 2008 Published by Elsevier B.V.

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We describe the canonical and microcanonical Monte Carlo algorithms for different systems that can be described by spin models. Sites of the lattice, chosen at random, interchange their spin values, provided they are different. The canonical ensemble is generated by performing exchanges according to the Metropolis prescription whereas in the microcanonical ensemble, exchanges are performed as long as the total energy remains constant. A systematic finite size analysis of intensive quantities and a comparison with results obtained from distinct ensembles are performed and the quality of results reveal that the present approach may be an useful tool for the study of phase transitions, specially first-order transitions. (C) 2009 Elsevier B.V. All rights reserved.

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We contrast Free Trade Areas involving Mercosul and the EU25, the US and China, respectively, using a new CGE model and associated database. Roughly, the China FTA lies halfway the other two, a bias towards the US pattern being suggested. When considering China a new Northern partner, protective deals don’t seem advisable. China’s advantages should prevail when facing the US or the EU: its need of capital goods, for instance, may open profitable cross-exchanges. China’s emergence can be a positive factor, if placed in an enlarged policy space where, together with its Asian neighbours, it counter-balances the US-EU polarity.

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Esta pesquisa aplica o cálculo dos tempos de trabalho, incorporados às exportações de diferentes países, para avaliar de um ângulo novo as relações de troca internacionais. Ao final, ela enfoca as diferenças de critério que resultam na avaliação social de projetos.

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A redução dos índices de inflação introduzida no Brasil pelo Plano Real trouxe alterações nos mais diferentes aspectos da vida econômica do país. Este trabalho visa analisar as principais alterações provocadas nos mercados de ações, analisando os impactos na Bovespa - Bolsa de Valores de São Paulo. Para tal foram analisadas as principais variáveis e medidas estatísticas que descrevem a Bovespa, como, por exemplo, a volatilidade e risco sistemático, nos períodos de quatro anos anteriores e posteriores ao início do Plano Real. De forma a separar os efeitos causados pelo Plano Real de outros de extensão global, utilizamos séries de controles baseadas em índices de bolsas da América Latina e de mercados centrais. Os resultados das análises realizadas indicam que houve uma redução da volatilidade no período pós-real em relação ao pré-real, o risco sistemático dos ativos brasileiros não se alterou, e o Ibovespa tornou-se menos eficiente em comparação com uma carteira formada pelos índices dos mercados centrais.

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Este relatório intitulado “Pesquisa sobre o ECR na Relação Fornecedor X Atacadista no Brasil”, foi desenvolvido pelo Professor Manoel de Andrade e Silva Reis, para o Núcleo de Pesquisas e Projetos (NPP) da Fundação Getúlio Vargas de São Paulo. Inicialmente apresenta alguns conceitos importantes para o entendimento do texto e faz considerações gerais sobre o ECR no Brasil e seu histórico. A principal parte do trabalho é a pesquisa realizada com 10 FORNECEDORES e 20 ATACADISTAS, sendo que 60% dos FORNECEDORES e 40% dos ATACADISTAS responderam aos questionários. As principais conclusões da pesquisa são: 1) Existem sérios obstáculos a transpor para a implantação abrangente do ECR na relação FORNECEDOR X ATACADISTA no Brasil, como: a) O setor ATACADISTA tem um forte preconceito com relação ao ECR, pelo receio de perda de mercado com a implantação de uma nova forma de fazer negócio. Isso evita que seus membros aprofundem o conhecimento das suas estratégias e ferramentas; b) Empresas ATACADISTAS tendem a ser muito fechadas, dificilmente abrindo suas informações para fornecedores, um dos requisitos básicos para a implantação bem sucedida do ECR. Têm também grande rivalidade com seus pares ATACADISTAS. c) O setor ATACADISTA desconfia das verdadeiras intenções dos FORNECEDORES. Há ATACADISTAS que chegaram a implantar uma ferramenta do ECR para teste e desistiram, por sentirem que os FORNECEDORES fogem aos acordos estabelecidos, visando, em especial, preencher as cotas de venda. 2) Na opinião das empresas ATACADISTAS, a sobrevivência setor depende de fatores como: a) Necessidade de uma radical mudança cultural das empresas, de forma a adotar os conceitos de compra e venda necessários no ECR; b) Necessidade de especialização em canais escolhidos e nos produtos característicos dos mesmos, visando tornar-se especialista na sua comercialização; c) Gestão mais adequada dos níveis de estoque; d) Maior agilidade no acesso ao pequeno varejo. 3) Fatores que podem aumentar a atratividade do setor ATACADISTA para os FORNECEDORES: a) Redução do número de transações; b) Redução dos custos pelos elevados volumes; c) Prestação de serviços ao pequeno varejo (devoluções, trocas, promoções, treinamento e incentivos); d) Pulverização das vendas.

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Esse estudo pretende identificar os operadores que caracterizam a dependência, as variáveis relacionadas a investimentos específicos para a condução da relação transacional e salvaguardas desses investimentos segundo a definição do auto-serviço e dos seus fornecedores no Brasil.

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According to Bourdieu (1994), there are social camps where the economic logic works upside down. Therefore, the expression ¿family business¿ is paradoxical because inside it resides two distinct and, sometimes, antagonistic logics: the business logic, whose goal is the profit, and the family logic, which aims at the common welfare. That is why one must consider the symbolical exchanges influences on the social relations more than in any other kind of company. Based on these concepts, this research presents an overview of the small and medium brazilian family business universe.

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This study approaches the question of organizations in search for competitiveness when globalization, knowledge and technological advances in the First World is a challenge in developing countries. The case study research focus on Bahia Sul ¿ a large organization which belongs to the important sector of paper and cellulose, especially in terms of exports. This study analyses an organization in that underpriviledged situation of a third world country in which the majority of organizational strategies are heavily thrown on people who are simultaneously reduced to instruments for economic results and who are highly demanded in terms of productivity and creativity. Due to that reality, references chosen present two key contrasting concepts. Mass man, going back to Taylor¿s blue collars as well as to Marcel¿s knowledgeable but empty words man, whose abilities do not feet his needs, in contrast with rogerian expectations of person as a mutable and continuously enriched human being and with habermasian position looking for political and decision making participation in work an social situations. Results show a strong presence of mass man, despite his technological knowledge, and scarce indications of the social man and which appears in mere aspirations out of labor situations. Conclusions emphasize a need for coherence between organizational practices in search for competitiveness and expectations on persons¿ performance because they stimulate exchanges in terms of working places for obedience and some material comfort which is aggravated by the fact that any possibility of personal fulfillment is interpreted as only possible in out of work situations. Competitiveness in such a context is not to be expected.

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O modelo de desenvolvimento sustentável trata de questões como a iniqüidade social, as limitações ambientais e a necessidade de compatibilizar o presente com as expectativas das gerações futuras. O consumo contemporâneo, hedonista e individualista, de troca de informações, de diferenciação social e de vocação consumista, parece dificultar que essas questões sejam ponderadas e se priorize a sustentabilidade ambiental. Como uma direção de comportamento em que o consumidor está orientado pelo senso de integração coletiva, de responsabilidade com os outros e o ambiente, o consumo ético estabelece uma ponte entre consumo contemporâneo e sustentabilidade. Como objetivo deste estudo, de caráter exploratório, busca-se conhecer tendências de comportamento para o consumo ético, um tema ainda incipiente no campo das ciências sociais. No levantamento bibliográfico, procurou-se integrar conteúdos que delimitassem a interdisciplinaridade entre consumo, desenvolvimento sustentável e ética, gerando as variáveis de estudo. Foram pesquisados estudantes como “líderes do amanhã” por sua influência nas organizações. A amostragem foi não probabilística por julgamento. O instrumento de pesquisa, baseado em escala de Likert de sete pontos, foi aplicado para alunos de graduação e pós-graduação em Administração. Foram utilizadas as análises multivariada fatorial e de agrupamento. Como resultado, obteve-se uma taxonomia da amostra pesquisada, como: “consciente cético”, “seguidor independente”, “teórico não praticante” e “individualista dissonante”. Este estudo reforça o achado prévio do levantamento bibliográfico de que há um paradoxo no individualismo contemporâneo, sendo concomitantemente consumista e ecológico. Também sugere a hipótese de que o sexo, trabalhar ou não e a escolaridade materna influenciam a aprendizagem do consumidor para questões ambientais, a decisão de participar em um pacto global sobre o consumo e a responsabilidade com as gerações futuras. Concluiu-se que a ética do discurso pode ser uma referência para a compreensão da troca de informações para o desenvolvimento sustentável e que o consumidor pesquisado não conforma um consumo ético, estabelecendo estágios de comportamento que não associam teoria e prática para a sustentabilidade ambiental