17,550 research outputs found

    Scotin, a novel p53-inducible proapoptotic protein located in the ER and the nuclear membrane

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    p53 is a transcription factor that induces growth arrest or apoptosis in response to cellular stress. To identify new p53-inducible proapoptotic genes, we compared, by differential display, the expression of genes in spleen or thymus of normal and p53 nullizygote mice after γ-irradiation of whole animals. We report the identification and characterization of human and mouse Scotin homologues, a novel gene directly transactivated by p53. The Scotin protein is localized to the ER and the nuclear membrane. Scotin can induce apoptosis in a caspase-dependent manner. Inhibition of endogenous Scotin expression increases resistance to p53-dependent apoptosis induced by DNA damage, suggesting that Scotin plays a role in p53-dependent apoptosis. The discovery of Scotin brings to light a role of the ER in p53-dependent apoptosis

    FM 047-02: a collisional pair of galaxies with a ring

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    Aims. We investigate the nature of the galaxy pair FM 047-02, which has been proposed as an archetype of the Solitaire types of peculiar (collisional) ring galaxies. Methods. The study is based on long-slit spectrophotometric data in the range of 3500-9500 angstrons obtained with the Gemini Multi-ObjectComment: 07 pages, 06 figures, 02 tables. arXiv admin note: text overlap with arXiv:1206.071

    Análise comparativa da quantificação da acção da neve de acordo com o RSA, a norma espanhola NBE e o EC1

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    A quantificação da acção da neve de acordo com a regulamentação em vigor em Portugal, Espanha e com o estabelecido no Eurocódigo 1 fornece resultados muito distintos. Neste trabalho é realizada uma análise comparativa entre o método de cálculo indicado pelo Regulamento de Segurança e Acções para Estruturas de Edifícios e Pontes, a norma espanhola NBE e o Eurocódigo 1. Foram analisados e comparados os vários parâmetros intervenientes na quantificação da acção da neve

    Tailored graph ensembles as proxies or null models for real networks I: tools for quantifying structure

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    We study the tailoring of structured random graph ensembles to real networks, with the objective of generating precise and practical mathematical tools for quantifying and comparing network topologies macroscopically, beyond the level of degree statistics. Our family of ensembles can produce graphs with any prescribed degree distribution and any degree-degree correlation function, its control parameters can be calculated fully analytically, and as a result we can calculate (asymptotically) formulae for entropies and complexities, and for information-theoretic distances between networks, expressed directly and explicitly in terms of their measured degree distribution and degree correlations.Comment: 25 pages, 3 figure

    Interplay between superconductivity and itinerant magnetism in underdoped Ba1x_{1-x}Kx_xFe2_2As2_2 (x=x= 0.2) probed by the response to controlled point-like disorder

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    The response of superconductors to controlled introduction of point-like disorder is an important tool to probe their microscopic electronic collective behavior. In the case of iron-based superconductors (IBS), magnetic fluctuations presumably play an important role in inducing high temperature superconductivity. In some cases, these two seemingly incompatible orders coexist microscopically. Therefore, understanding how this unique coexistence state is affected by disorder can provide important information about the microscopic mechanisms involved. In one of the most studied pnictide family, hole-doped Ba1x_{1-x}Kx_xFe2_2As2_2 (BaK122), this coexistence occurs over a wide range of doping levels, 0.16~x\lesssim x \lesssim ~0.25. We used relativistic 2.5 MeV electrons to induce vacancy-interstitial (Frenkel) pairs that act as efficient point-like scattering centers. Upon increasing dose of irradiation, the superconducting transition temperature TcT_c decreases dramatically. In the absence of nodes in the order parameter this provides a strong support for a sign-changing s±s_{\pm} pairing. Simultaneously, in the normal state, there is a strong violation of the Matthiessen's rule and a decrease (surprisingly, at the same rate as TcT_c) of the magnetic transition temperature TsmT_{sm}, which indicates the itinerant nature of the long-range magnetic order. Comparison of the hole-doped BaK122 with electron-doped Ba(Fex_xCo1x_{1-x})2_2As2_2 (FeCo122) with similar TsmT_{sm}\sim110~K, x=x=0.02, reveals significant differences in the normal states, with no apparent Matthiessen's rule violation above TsmT_{sm} on the electron-doped side. We interpret these results in terms of the distinct impact of impurity scattering on the competing itinerant antiferromagnetic and s±s_{\pm} superconducting orders

    Optical and Near Infrared Study of the Cepheus E outflow, a very low excitation object

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    We present images and spectra of the Cepheus E (Cep E) region at both optical and infrared wavelengths. Only the brightest region of the southern lobe of the Cep E outflow reveals optical emission, suggesting that the extinction close to the outflow source plays an important r\^ole in the observed difference between the optical and IR morphologies. Cep E is a unique object since it provides a link between the spectroscopic properties of the optical Herbig-Haro (HH) objects and those of deeply embedded outflows.Comment: Accepted Astron. J., 8 files: paper, tables plus 6 figure

    Modelagem de crescimento e produção usando o modelo Simflora.

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    Importância da modelagem de dinâmica florestal na Amazônia Brasileira; Modelagem de crescimento e produção usando o Simflora; Outros documentos disponíveis; Instalação; Simulações únicas; Dados; Começando; Janelas de exibição; Rodando o modelo; Resultados; Simulando silvicultura; A escolha de módulos e valores dos parâmetros; Exemplo; Simulações múltiplas; Começando uma simulação múltipla; Criando um arquivo de dados de saída; Rodando simulações múltiplas; Examinando e analisando os resultados; Experiências de uso do Simflora e suas implicações para políticas públicas; Indonésia; Guiana Inglesa; Brasil; Padrões observados em relação à exploração madeireira e às lacunas de conhecimento de dinâmica florestal de diferentes países tropicais
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