982 resultados para link function
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Using US data for the period 1967:5-2002:4, this paper empirically investigates the performance of a Fed’s reaction function (FRF) that (i) allows for the presence of switching regimes, (ii) considers the long-short term spread in addition to the typical variables, (iii) uses an alternative monthly indicator of general economic activity suggested by Stock and Watson (1999), and (iv) considers interest rate smoothing. The estimation results show the existence of three switching regimes, two characterized by low volatility and the remaining regime by high volatility. Moreover, the scale of the responses of the Federal funds rate to movements in the rate of inflation and the economic activity index depends on the regime. The estimation results also show robust empirical evidence that the importance of the term spread in the FRF has increased over the sample period and the FRF has been more stable during the term of office of Chairman Greenspan than in the pre-Greenspan period.
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Traça um panorama histórico da ação fiscalizadora do Congresso Nacional em relação à atividade de inteligência nacional, mais precisamente da Agência Brasileira de Inteligência – ABIN, órgão estatal responsável por essa atividade, na salvaguarda dos conhecimentos sigilosos do Estado, haja vista ser o Congresso Nacional, o órgão responsável pela fiscalização externa da rede e seus componentes. Identificar as vulnerabilidades existentes, principalmente no que tange aos recursos humanos, capital mais precioso desse processo, mas que, pela ganância, vaidade e cobiça, se torna o elo mais vulnerável. A Atividade de Inteligência dentre todas as áreas de controle democrático é a mais arriscada, haja vista a sua importância para o progresso e desenvolvimento de uma Nação. É uma atividade que se desenvolve diuturnamente buscando minimizar as desconfianças de todos os órgãos e organizações estatais envolvidos no processo. A salvaguarda dos documentos e de informações governamentais sigilosas é primordial para a segurança do Estado. A institucionalização da Atividade de Inteligência no Brasil, a partir de 1927, trouxe ao país uma situação antes exercida apenas no âmbito militar. Com leis, decretos, portarias e denominações várias do órgão nacional responsável, são desenvolvidas as ações de coordenação do fluxo de informações necessárias às decisões governamentais. A pesquisa foi realizada com base em fontes históricas e documentais, ressaltando o papel do Congresso Nacional na sua função de fiscalização das políticas de inteligência.
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Organismal survival in marine habitats is often positively correlated with habitat structural complexity at local (within-patch) spatial scales. Far less is known, however, about how marine habitat structure at the landscape scale influences predation and other ecological processes, and in particular, how these processes are dictated by the interactive effect of habitat structure at local and landscape scales. The relationship between survival and habitat structure can be modeled with the habitat-survival function (HSF), which often takes on linear, hyperbolic, or sigmoid forms. We used tethering experiments to determine how seagrass landscape structure influenced the HSF for juvenile blue crabs Callinectes sapidus Rathbun in Back Sound, North Carolina, USA. Crabs were tethered in artificial seagrass plots of 7 different shoot densities embedded within small (1 – 3 m2) or large (>100 m2) seagrass patches (October 1999), and within 10 × 10 m landscapes containing patchy (<50% cover) or continuous (>90% cover) seagrass (July 2000). Overall, crab survival was higher in small than in large patches, and was higher in patchy than in continuous seagrass. The HSF was hyperbolic in large patches and in continuous seagrass, indicating that at low levels of habitat structure, relatively small increases in structure resulted in substantial increases in juvenile blue crab survival. However, the HSF was linear in small seagrass patches in 1999 and was parabolic in patchy seagrass in 2000. A sigmoid HSF, in which a threshold level of seagrass structure is required for crab survival, was never observed. Patchy seagrass landscapes are valuable refuges for juvenile blue crabs, and the effects of seagrass structural complexity on crab survival can only be fully understood when habitat structure at larger scales is considered.
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Eguíluz, Federico; Merino, Raquel; Olsen, Vickie; Pajares, Eterio; Santamaría, José Miguel (eds.)