63 resultados para Affinities
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Proteins containing the classical nuclear localization sequences (NLSs) are imported into the nucleus by the importin-α/β heterodimer. Importin-α contains the NLS binding site, whereas importin-β mediates the translocation through the nuclear pore. We characterized the interactions involving importin-α during nuclear import using a combination of biophysical techniques (biosensor, crystallography, sedimentation equilibrium, electrophoresis, and circular dichroism). Importin-α is shown to exist in a monomeric autoinhibited state (association with NLSs undetectable by biosensor). Association with importin-β (stoichiometry, 1:1; K D = 1.1 × 10 -8 M) increases the affinity for NLSs; the importin-α/β complex binds representative monopartite NLS (simian virus 40 large T-antigen) and bipartite NLS (nucleoplasmin) with affinities (K D = 3.5 × 10 -8 M and 4.8 × 10 -8 M, respectively) comparable with those of a truncated importin-α lacking the autoinhibitory domain (T-antigen NLS, K D = 1.7 × 10 -8 M; nucleoplasmin NLS, K D = 1.4 × 10 -8 M). The autoinhibitory domain (as a separate peptide) binds the truncated importin-α, and the crystal structure of the complex resembles the structure of full-length importin-α. Our results support the model of regulation of nuclear import mediated by the intrasteric autoregulatory sequence of importin-α and provide a quantitative description of the binding and regulatory steps during nuclear import.
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Calmoniids (Delo, 1935) are the most common and abundant group of trilobites of the fossil record of the Devonian Ponta Grossa Formation in the Apucarana sub-basin. Although known since the past century, the study of calmoniids has been taxonomically and stratigraphically biased. This is because some authors centered their studies on some particular genera from a few stratigraphic horizons within the basal portion of the Ponta Grossa Formation. The analyses of 398 specimens of calmoniid trilobites of the rocks of Jaguariaiva Member of the Ponta Grossa Formation, mainly from Tibagi county in the state of Paraná, Brazil, indicate the presence of specimens that are referable to Metacryphaeus rotundatus (Kozlowski, 1923). This is the first record of M. rotundatus in Brazilian Devonian rocks. Metacryphaeus rotundatus is a conspicuous species of the Emsian rocks of the Icla Formation, Bolivia. Although the affinities of the trilobite fauna of the Devonian Paraná Basin, in the context of the Malvinokaffric realm, are with the Brazilian and South Africa provinces, this finding is in accordance with new evidence (e.g., conulariids, homalonotids trilobites), indicating the presence of cosmopolitan species with Andean affinities. Metacryphaeus rotundatus lived in a broad paleoclimatic range, from a temperate, cold temperate to a subpolar climate. Finally, in the Devonian of the Paraná Basin, M. rotundatus lived and were preserved in muddy, organic rich bottoms, deposited in offshore waters, below the storm wave base, associated to marine flooding surfaces.
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We present the results of the first molecular analysis of the phylogenetic affinities of the Asian colubroid genus Sibynophis. We recovered a sister-group relationship between Sibynophis and the New World Scaphiodontophis. Although Liophidium sometimes is associated with these genera, the relationship is distant. Morphological characters that Liophidium shares with Sibynophis and Scaphiodontophis are resolved as homoplasies that probably reflect the similarities of their specialized feeding habits. The traditional subfamily Sibynophiinae is elevated to the family-level, and Scaphiodontophiinae is placed in its synonymy.
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In a letter to Nature (February, 2011), Xunlai Yuan and collaborators recorded carbon compression fossils from black shales of the Lantian Formation (Ediacaran), southern Anhui Province, South China. The new fossils, described under five morphological types (Types A to E), exhibit degrees of morphological differentiation suggesting that they were multicellular eukaryotes. Some of the Lantian macrofossils were interpreted as algae, but others are of unknown affinities. For reasons noted in this discussion, Type A fossils attracted our particular attention, and we suggest an alternative interpretation of their affinities. According to our view, some of them (at least those with three faces and no globose holdfast at their base) may represent conulariid cnidarians or close medusozoan relatives. The undistorted organism probably was a three-sided cone in life. We believe that our suggested alternative interpretations of the anatomy and affinities of the fossils in question can be useful in guiding future research on the oldest currently known fossil assemblage of multicellular organisms. Copyright © 2012.
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The expansion of citizen participation in the public sphere depends directly of access information on the performance of elected representatives, especially with regard to their voting decisions during their terms. The Information Science can assist in this process, proposing and evaluating models of access to such information that may be obtained from data to be provided by the official websites from legislative, in levels federal, state and municipal. It is proposed in this paper to analyze the process of collecting and using of data about votes of senators in order to promote the use of this model in other spheres. From analyzed data a affinity matrix was developed to identifying the relationship between each of the parliamentary with others, based on the similarities of the decisions taken in all the open votes. It was also analyzed the development of initial visualizations and the extension of the scope of the search through the application of data obtained in all the affinities between parliamentarians and to obtain an average affinity between parties, enabling new dimensions of analysis to the data collected. The preparation of the full matrix of relations of affinity among parliamentarians can provide a new horizon of possibilities for developing new forms of visualization and analysis, increasing the visibility of parliamentary actions with society.
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Pós-graduação em Ciências Sociais - FFC
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Ciência da Informação - FFC
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)