15,382 research outputs found

    Avaliação de ferramentas para detecção de interações epistáticas para fenótipos quantitativos em estudos de associação genômica ampla.

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    Variações genéticas presentes em uma população podem estar associadas a muitas características como susceptibilidade a doenças em humanos (ex: diabetes, câncer, e doenças psiquiátricas). Atualmente, tecnologias de genotipagem de baixo custo, baseadas em marcadores moleculares do tipo polimorfismo de base única Single Nucleotide Polymorphism (SNP) são utilizados para identificar variações desse tipo associadas com doenças. Tais estudos, são denominados, estudos de associação genômica ampla, Genome Wide Association Studies (GWAS). No caso de espécies de interesse agropecuário, essas variações genéticas estão relacionadas a características que podem impactar ganhos de qualidade e produção. Portanto, é de extrema importância a utilização de novos métodos computacionais para identificação desses marcadores, já que isto pode contribuir para a seleção de indivíduos superiores, considerando os traços fenotípicos de interesse em espécies animais utilizadas em programas de melhoramento coordenados pela Empresa Brasileira de Pesquisa Agropecuária (Embrapa)

    Fourier Eigenfunctions, Uncertainty Gabor Principle and Isoresolution Wavelets

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    Shape-invariant signals under Fourier transform are investigated leading to a class of eigenfunctions for the Fourier operator. The classical uncertainty Gabor-Heisenberg principle is revisited and the concept of isoresolution in joint time-frequency analysis is introduced. It is shown that any Fourier eigenfunction achieve isoresolution. It is shown that an isoresolution wavelet can be derived from each known wavelet family by a suitable scaling.Comment: 6 pages, XX Simp\'osio Bras. de Telecomunica\c{c}\~oes, Rio de Janeiro, Brazil, 2003. Fixed typo

    Progesterone in breast cancer angiogenesis

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    The involvement of steroid hormones in breast carcinogenesis is well established. Recent evidence suggests that angiogenesis can be regulated by hormones. Both oestrogen and progesterone have been implicated in the angiogenic process of hormone-dependent cancers, such as breast cancer. Vascular Endothelial Growth Factor (VEGF) is a growth factor involved in angiogenesis in breast cancer that is up-regulated by estrogens. In our study we evaluated the role of progesterone in the expression of this angiogenic growth factor commonly up-regulated in breast cancer. Our findings indicate that progesterone activates an angiogenic pathway involving VEGF stimulation. The elucidation of specific angiogenic pathways promoted by progesterone can raise new therapeutic targets at least in a subset of breast cancers responsive to progesterone

    Exceptional bundles of homological dimension k{k}

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    We characterize exceptional vector bundles on Pn of arbitrary homological dimension defined by a linear resolution. Moreover, we determine all Betti numbers of such resolution.info:eu-repo/semantics/acceptedVersio

    Lobby index as a network centrality measure

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    We study the lobby index (l-index for short) as a local node centrality measure for complex networks. The l-inde is compared with degree (a local measure), betweenness and Eigenvector centralities (two global measures) in the case of biological network (Yeast interaction protein-protein network) and a linguistic network (Moby Thesaurus II). In both networks, the l-index has poor correlation with betweenness but correlates with degree and Eigenvector. Being a local measure, one can take advantage by using the l-index because it carries more information about its neighbors when compared with degree centrality, indeed it requires less time to compute when compared with Eigenvector centrality. Results suggests that l-index produces better results than degree and Eigenvector measures for ranking purposes, becoming suitable as a tool to perform this task.Comment: 11 pages, 4 figures. arXiv admin note: substantial text overlap with arXiv:1005.480

    Combining exclusive semi-leptonic and hadronic B decays to measure |V_ub|

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    The Cabibbo-Kobayashi-Maskawa matrix element |V_ub| can be extracted from the rate for the semi-leptonic decay B -> pi + l + antineutrino_l, with little theoretical uncertainty, provided the hadronic form factor for the B -> pi transition can be measured from some other B decay. In here, we suggest using the decay B -> pi J\psi. This is a color suppressed decay, and it cannot be properly described within the usual factorization approximation; we use instead a simple and very general phenomenological model for the b d J\psi vertex. In order to relate the hadronic form factors in the B -> pi J\psi and B -> pi + l + antineutrino_l decays, we use form factor relations that hold for heavy-to-light transitions at large recoil.Comment: Latex, 7 pages, no figure

    Erlang Code Evolution Control

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    During the software lifecycle, a program can evolve several times for different reasons such as the optimisation of a bottle-neck, the refactoring of an obscure function, etc. These code changes often involve several functions or modules, so it can be difficult to know whether the correct behaviour of the previous releases has been preserved in the new release. Most developers rely on a previously defined test suite to check this behaviour preservation. We propose here an alternative approach to automatically obtain a test suite that specifically focusses on comparing the old and new versions of the code. Our test case generation is directed by a sophisticated combination of several already existing tools such as TypEr, CutEr, and PropEr; and other ideas such as allowing the programmer to chose an expression of interest that must preserve the behaviour, or the recording of the sequences of values to which this expression is evaluated. All the presented work has been implemented in an open-source tool that is publicly available on GitHub.Comment: Pre-proceedings paper presented at the 27th International Symposium on Logic-Based Program Synthesis and Transformation (LOPSTR 2017), Namur, Belgium, 10-12 October 2017 (arXiv:1708.07854
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