283 research outputs found

    Investment Responsibility of Professional Trustees

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    Professor tutor : contribuições ao processo de aprendizagem em ead

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    Uma das modalidades de ensino amplamente discutida e considerada emergente na sociedade contemporânea, para atender a demanda crescente de estudantes que ingressam no ensino superior, é a educação a distância, que recorre as ações de tutoria para atendimento e elucidação das dúvidas dos estudantes. Este texto tem por objetivo promover reflexões sobre a ação didática do professor tutor na Educação a Distância, portanto abordamos algumas questões teóricas e epistemológicas que envolvem a educação; conversamos sobre a importância da utilização de ferramentas que propiciem a interação, a cooperação e a autonomia do estudante nessa modalidade de ensino; e tecemos algumas considerações sobre a prática da tutoria

    Morfologia de machos e fêmeas de Euglossa annectans Dresler 1982 (Hymenoptera, Apidae, Euglossini).

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    Foram coletados dados de morfometria de machos e fêmeas de Euglossa annectans em condições de laboratório, de um grupo de células separado artificialmente, a partir de um ninho alojado espontaneamente em caixa racional de abelhas sem ferrão

    Scaling and intermittency of brain events as a manifestation of consciousness

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    We discuss the critical brain hypothesis and its relationship with intermittent renewal processes displaying power-law decay in the distribution of waiting times between two consecutive renewal events. In particular, studies on complex systems in a "critical" condition show that macroscopic variables, integrating the activities of many individual functional units, undergo fluctuations with an intermittent serial structure characterized by avalanches with inverse-power-law (scale-free) distribution densities of sizes and inter-event times. This condition, which is denoted as "fractal intermittency", was found in the electroencephalograms of subjects observed during a resting state wake condition. It remained unsolved whether fractal intermittency correlates with the stream of consciousness or with a non-task-driven default mode activity, also present in non-conscious states, like deep sleep. After reviewing a method of scaling analysis of intermittent systems based of event-driven random walks, we show that during deep sleep fractal intermittency breaks down, and re-establishes during REM (Rapid Eye Movement) sleep, with essentially the same anomalous scaling of the pre-sleep wake condition. From the comparison of the pre-sleep wake, deep sleep and REM conditions we argue that the scaling features of intermittent brain events are related to the level of consciousness and, consequently, could be exploited as a possible indicator of consciousness in clinical applications

    The neonicotinoid insecticide thiacloprid impacts upon bumblebee colony development under field conditions

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    The impacts of pesticides, and in particular of neonicotinoids, on bee health remain much debated. Many studies describing negative effects have been criticised as the experimental protocol did not perfectly simulate real-life field scenarios. Here, we placed free-flying bumblebee colonies next to raspberry crops that were either untreated or treated with the neonicotinoid thiacloprid as part of normal farming practice. Colonies were exposed to the raspberry crops for a two week period before being relocated to either a flower-rich or flower-poor site. Overall, exposed colonies were more likely to die prematurely, and those that survived reached a lower final weight and produced 46% fewer reproductives than colonies placed at control farms. The impact was more marked at the flower-rich site (all colonies performed poorly at the flower poor site). Analysis of nectar and pollen stores from bumblebee colonies placed at the same raspberry farms revealed thiacloprid residues of up to 771ppb in pollen and up to 561ppb in nectar. The image of thiacloprid as a relatively benign neonicotinoid should now be questioned
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