4,149 research outputs found
Giant Pulses from the Millisecond Pulsar B1821-24
We have carried out a survey for `giant pulses' in 5 millisecond pulsars. We
detect individual pulses from the high Edot pulsar PSR B1821-24 with energies
exceeding 50x the mean pulse energy. These giant pulses are concentrated in a
narrow phase window coincident with the power-law non-thermal pulse seen in
hard X-rays. This is the third example of the giant pulse phenomenon. It
supports the idea that large B fields in the outer magnetosphere are critical
to the formation of such pulses and further suggests a direct connection
between giant pulses and high energy emission.Comment: 6pp, 3 figures. To Appear in ApJ Letters, Vol 55
Episodic memory retrieval, parietal cortex, and the default mode network: Functional and topographic analyses
The default mode network (DMN) is often considered a functionally homogeneous system that is broadly associated with internally directed cognition (e.g., episodic memory, theory of mind, self-evaluation). However, few studies have examined how this network interacts with other networks during putative default processes such as episodic memory retrieval. Using functional magnetic resonance imaging, we investigated the topography and response profile of human parietal regions inside and outside the DMN, independently defined using task-evoked deactivations and resting-state functional connectivity, during episodic memory retrieval. Memory retrieval activated posterior nodes of the DMN, particularly the angular gyrus, but also more anterior and dorsal parietal regions that were anatomically separate from the DMN. The two sets of parietal regions showed different resting-state functional connectivity and response profiles. During memory retrieval, responses in DMN regions peaked sooner than non-DMN regions, which in turn showed responses that were sustained until a final memory judgment was reached. Moreover, a parahippocampal region that showed strong resting-state connectivity with parietal DMN regions also exhibited a pattern of task-evoked activity similar to that exhibited by DMN regions. These results suggest that DMN parietal regions directly supported memory retrieval, whereas non-DMN parietal regions were more involved in postretrieval processes such as memory-based decision making. Finally, a robust functional dissociation within the DMN was observed. Whereas angular gyrus and posterior cingulate/precuneus were significantly activated during memory retrieval, an anterior DMN node in medial prefrontal cortex was strongly deactivated. This latter finding demonstrates functional heterogeneity rather than homogeneity within the DMN during episodic memory retrieval
Siger - orientações para interface gráfica.
Este documento tem por objetivo descrever as diretrizes para o projeto da interface de entrada de dados do Sistema de Informação Gerencial da Embrapa (SIGER), promovendo uma uniformidade visual dos elementos gráficos que o compoem. Como consequência desta uniformidade, espera-se que todo o SIGER possua o mesmo padrão de interface gráfica, o que irá facilitar a interacão do usuário com o sistema. São estabelecidas orientações para a disposição de elementos gráficos na tela e a definição de algumas das suas propriedades básicas. Algumas caracteristicas gerais do ambiente Windows sao mantidas na aplicação conforme a configuração definida pelo usuário, como exemplo cor das janelas ativa e inativa, texto da janela, texto da mensagem, cor do item de menu normal, desativado e selecionado.bitstream/item/76631/1/CNPTIA-COM.TEC.-4-98.pd
Avaliação da expansão da cana-de-açúcar em Mato Grosso do Sul (MS) analisando a relação entre o clima atual e a produtividade da cultura.
Este trabalho teve como objetivos relacionar os dados de temperatura e precipitação (2000 a 2010) com os dados de produtividade (área colhida e valor da produção), analisando a influência das alterações do clima atual na expansão da cana-de-açúcar em MS, e o de comparar a produtividade da cana-de-açúcar com a produtividade das culturas de soja e algodão
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