665 research outputs found

    Asymmetries in e+e−→ffˉe^+e^-\to f\bar{f} processes at ILC for models with an extra neutral vector boson Z′Z^\prime

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    Many extensions of the standard model predict the existence of extra neutral vector bosons, generically referred as Z′Z^\prime. This boson may be discovered at the LHC but in this case it will be necessary to study the respective parameters in order to discriminate to which model it belongs to. This is a task for a much clean lepton linear collider as the future ILC. In this paper we develop an exemplary study of the capability of several asymmetries on and off Z′Z^\prime peak in discriminating among those extensions with (almost) no ambiguities.Comment: 27 pages, 9 figures. Version to be published in PRD. Title changed in the journa

    Transferibilidade de locos SSR de Astrocaryum aculeatum Mart. para Astrocaryum vulgare Mart.

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    Este trabalho foi realizado com o objetivo de testar a transferibilidade de locos SSR de Astrocaryum aculeatum para a espécie Astrocaryum vulgare. Para isso, foram aplicados doze locos desenvolvidos para A. aculeatum em seis amostras de DNA obtidas de matrizes de A. vulgare de diferentes procedências. As reações de amplificação foram conduzidas de acordo com o protocolo desenvolvido por Ramos (2012), com pequenas adaptações. Os produtos amplificados foram aplicados em gel de agarose ultra pura a 1,5%, corado com brometo de etídio e submetido à eletroforese horizontal por 1:30 horas. Os perfis dos géis foram fotodocumentados e as imagens armazenadas digitalmente. A transferibilidade dos locos foi avaliada com base na amplificação de produtos e na sua nitidez. Dos doze locos testados, seis apresentaram amplificação satisfatória (visualização do produto), perfazendo uma taxa de transferibilidade de 50%, sugerindo que as espécies possuam alto grau de parentesco. Em todos os locos amplificados não foi detectada a presença de produtos secundários, sendo, portanto, úteis para acessar o genoma de A. vulgare

    ZB−L′Z^{\prime}_{B-L} phenomenology at LHC

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    We study the Z′Z^\prime phenomenology for two extensions of the Electroweak Standard Model (SM) which have an extra U(1)B−LU(1)_{B-L} gauge factor. We show the capabilities of the LHC in distinguishing the signals coming from these two extensions and both of them from the Standard Model background. In order to compare the behavior of these B−LB-L models we consider the reaction p+p⟶μ++μ−+Xp + p\longrightarrow \mu^+ + \mu^- + X and compute some observables as the total cross sections, number of events, forward-backward asymmetry, final particle distributions like rapidity, transverse momentum, and dimuon invariant mass, for two LHC regimes: s (L)=7\sqrt{s}\,({\cal L})=7 TeV (1 fb−11\, \textrm{fb}^{-1}) and 1414 TeV (100 fb−1100\, \textrm{fb}^{-1}) for MZ′M_{Z^{\prime}} = 1000 GeV and 1500 GeV. We show that by using appropriate kinematic cuts some of the observables considered here are able to extract different properties of the Z′Z^\prime boson, and hence providing information about to which B−LB-L model it belongs to.Comment: 21 pages, 17 figures, 4 table

    Interaction of eukaryotic translation initiation factor 4G with the nuclear cap-binding complex provides a link between nuclear and cytoplasmic functions of the m7 guanosine cap

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    In eukaryotes the majority of mRNAs have an m7G cap that is added cotranscriptionally and that plays an important role in many aspects of mRNA metabolism. The nuclear cap-binding complex (CBC; consisting of CBP20 and CBP80) mediates the stimulatory functions of the cap in pre-mRNA splicing, 3' end formation, and U snRNA export. As little is known about how nuclear CBC mediates the effects of the cap in higher eukaryotes, we have characterized proteins that interact with CBC in HeLa cell nuclear extracts as potential mediators of its function. Using cross-linking and coimmunoprecipitation, we show that eukaryotic translation initiation factor 4G (eIF4G), in addition to its function in the cytoplasm, is a nuclear CBC-interacting protein. We demonstrate that eIF4G interacts with CBC in vitro and that, in addition to its cytoplasmic localization, there is a significant nuclear pool of eIF4G in mammalian cells in vivo. Immunoprecipitation experiments suggest that, in contrast to the cytoplasmic pool, much of the nuclear eIF4G is not associated with eIF4E (translation cap binding protein of eIF4F) but is associated with CBC. While eIF4G stably associates with spliceosomes in vitro and shows close association with spliceosomal snRNPs and splicing factors in vivo, depletion studies show that it does not participate directly in the splicing reaction. Taken together the data indicate that nuclear eIF4G may be recruited to pre-mRNAs via its interaction with CBC and accompanies the mRNA to the cytoplasm, facilitating the switching of CBC for eIF4F. This may provide a mechanism to couple nuclear and cytoplasmic functions of the mRNA cap structure

    Complete mitochondrial sequences from Mesolithic Sardinia

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    Little is known about the genetic prehistory of Sardinia because of the scarcity of pre-Neolithic human remains. From a genetic perspective, modern Sardinians are known as genetic outliers in Europe, showing unusually high levels of internal diversity and a close relationship to early European Neolithic farmers. However, how far this peculiar genetic structure extends and how it originated was to date impossible to test. Here we present the first and oldest complete mitochondrial sequences from Sardinia, dated back to 10,000 yBP. These two individuals, while confirming a Mesolithic occupation of the island, belong to rare mtDNA lineages, which have never been found before in Mesolithic samples and that are currently present at low frequencies not only in Sardinia, but in the whole Europe. Preliminary Approximate Bayesian Computations, restricted by biased reference samples for Mesolithic Sardinia (the two typed samples) and Neolithic Europe (limited to central and north European sequences), suggest that the first inhabitants of the island have had a small or negligible contribution to the present-day Sardinian population, which mainly derives its genetic diversity from continental migration into the island by Neolithic times
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