Biomarcadores e desenvolvimento neurocomportamental: aspectos experimentais.

O monitoramento biológico da exposição a agroquímicos constitui-se em uma avaliação que qualifica e/ou quantifica a exposição de um indivíduo ou de uma amostra da população com o uso de amostras biológicas. Para a realização do monitoramento biológico é necessário o conhecimento de um biomarcador. Os agroquímicos em uso atualmente muitas vezes ocasionam sinais e sintomas que podem estar associados à exposição a mais de um princípio ativo. Nesse sentido, é importante estabelecer indicadores biológicos ou biomarcadores relacionados à exposição a esses produtos, indicadores esses mais específicos e baseados em critérios científicos bem estabelecidos.bitstream/CNPMA/6299/1/documentos_51.pd

Modeling non-thermal emission from stellar bow shocks

Runaway O- and early B-type stars passing throughout the interstellar medium at supersonic velocities and characterized by strong stellar winds may produce bow shocks that can serve as particle acceleration sites. Previous theoretical models predict the production of high energy photons by non-thermal radiative processes, but their efficiency is still debated. We aim to test and explain the possibility of emission from the bow shocks formed by runaway stars traveling through the interstellar medium by using previous theoretical models. We apply our model to AE Aurigae, the first reported star with an X-ray detected bow shock, to BD+43 3654, in which the observations failed in detecting high energy emission, and to the transition phase of a supergiant star in the late stages of its life.From our analysis, we confirm that the X-ray emission from the bow shock produced by AE Aurigae can be explained by inverse Compton processes involving the infrared photons of the heated dust. We also predict low high energy flux emission from the bow shock produced by BD+43 3654, and the possibility of high energy emission from the bow shock formed by a supergiant star during the transition phase from blue to red supergiant.Bow shock formed by different type of runaway stars are revealed as a new possible source of high energy photons in our neighbourhood

Como promover a fixacao de pesquisadores da Embrapa nos centros de pesquisas da Amazonia Ocidental.

Relata estudo realizado junto aos pesquisadores da Embrapa que trabalham em Unidades Descentralizadas localizadas na Amazônia Ocidental (Amazonas, Rondônia, Roraima, Amapá e Acre). Trabalho executado como prática do Curso de Administração em Ciência e Tecnologia ministrado pela Faculdade de Economia e Administração da USP. Coleta e tabulação dos dados foi realizada no período de julho a novembro/1993. Fez-se levantamento onde foram colhidas através de questionário apropriado, opinião de 60 pesquisadores, num universo de 128 pesquisadores que trabalham nessas Unidades. Procurou-se identificar razões de satisfação e insafisfação desses profissionais para o desenvolvimento de suas atividades, e dessa forma, ter uma percepção das razões da elevada taxa de evasão de pesquisadores que trabalham nas Unidades da Amazônia Ocidental.bitstream/item/58852/1/DOC-1838-0001.pdf(mimeografado)

A Configurational Approach to Comparative Corporate Governance

We seek to bring to the core of the study of comparative corporate governance analysis the idea that within countries and industries, there exist multiple configurations of firm level characteristics and governance practices leading to effective corporate governance. In particular, we propose that configurations composed of different bundles of corporate governance practices are a useful tool to examine corporate governance models across and within countries (as well as potentially to analyze over time changes). While comparative research, identifying stylized national models of corporate governance, has been fruitful to help us think about the key institutional and shareholder rights determining governance differences and similarities across countries, we believe that given the financialization of the corporate economy, current globalization trends of investment, and rapid information technology advances, it is important to shift our conceptualization of governance models beyond the dichotomous world of common-law/outsider/shareholder-oriented system vs. civil law/insider/stakeholder oriented system. Our claim is based on the empirical observation that there exists a wide range of firms that either (1) fall in the "wrong" corporate governance category; (2) are a hybrid of these two categories; or (3) should be placed into an entirely new category such as firms in emerging markets or state-owned firms. In addition, as Aguilera and Jackson (2003) argue, firms, regardless of their legal family constraints, their labor and product markets, and the development of the financial markets from which they can draw, have significant degrees of freedom to chose whether to implement different levels of a given corporate governance practice. That is, firms might chose to fully endorse a practice or simply seek to comply with the minimum requirements without truly internalizing the governance practice. An illustrative example of the different degrees of internalization of governance practices is the existing variation in firms' definition of director independence or disclosure of compensation systems. We first discuss the conceptual idea of configurations or bundles of corporate governance practices underscoring the concept of equifinal paths to given firm outcomes as well as the complementarity and substitution in governance practices. We then move to the practice level of analysis to show how three governance characteristics (legal systems, ownership and boards of directors) cannot be conceptualized independently, as each of them is contingent on the strength and prevalence of other governance practices. In the last section, we illustrate how different configurations are likely to playout across industries and countries, taking as the departing practice, corporate ownership.

The peremptory influence of a uniform background for trapping neutral fermions with an inversely linear potential

The problem of neutral fermions subject to an inversely linear potential is revisited. It is shown that an infinite set of bound-state solutions can be found on the condition that the fermion is embedded in an additional uniform background potential. An apparent paradox concerning the uncertainty principle is solved by introducing the concept of effective Compton wavelength