915 research outputs found

    The Forkhead Transcription Factor Foxl2 Is Sumoylated in Both Human and Mouse: Sumoylation Affects Its Stability, Localization, and Activity

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    The FOXL2 forkhead transcription factor is expressed in ovarian granulosa cells, and mutated FOXL2 causes the blepharophimosis, ptosis and epicanthus inversus syndrome (BPES) and predisposes to premature ovarian failure. Inactivation of Foxl2 in mice demonstrated its indispensability for female gonadal sex determination and ovary development and revealed its antagonism of Sox9, the effector of male testis development. To help to define the regulatory activities of FOXL2, we looked for interacting proteins. Based on yeast two-hybrid screening, we found that FOXL2 interacts with PIAS1 and UBC9, both parts of the sumoylation machinery. We showed that human FOXL2 is sumoylated in transfected cell lines, and that endogenous mouse Foxl2 is comparably sumoylated. This modification changes its cellular localization, stability and transcriptional activity. It is intriguing that similar sumoylation and regulatory consequences have also been reported for SOX9, the male counterpart of FOXL2 in somatic gonadal tissues

    Re-calibration of coronary risk prediction:An example of the Seven Countries Study

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    We aimed at performing a calibration and re-calibration process using six standard risk factors from Northern (NE, N = 2360) or Southern European (SE, N = 2789) middle-aged men of the Seven Countries Study, whose parameters and data were fully known, to establish whether re-calibration gave the right answer. Greenwood-Nam-D'Agostino technique as modified by Demler (GNDD) in 2015 produced chi-squared statistics using 10 deciles of observed/expected CHD mortality risk, corresponding to Hosmer-Lemeshaw chi-squared employed for multiple logistic equations whereby binary data are used. Instead of the number of events, the GNDD test uses survival probabilities of observed and predicted events. The exercise applied, in five different ways, the parameters of the NE-predictive model to SE (and vice-versa) and compared the outcome of the simulated re-calibration with the real data. Good re-calibration could be obtained only when risk factor coefficients were substituted, being similar in magnitude and not significantly different between NE-SE. In all other ways, a good re-calibration could not be obtained. This is enough to praise for an overall need of re-evaluation of most investigations that, without GNDD or another proper technique for statistically assessing the potential differences, concluded that re-calibration is a fair method and might therefore be used, with no specific caution

    Bottomonium and Drell-Yan production in p-A collisions at 450 GeV

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    The NA50 Collaboration has measured heavy-quarkonium production in p-A collisions at 450 GeV incident energy (sqrt(s) = 29.1 GeV). We report here results on the production of the Upsilon states and of high-mass Drell-Yan muon pairs (m > 6 GeV). The cross-section at midrapidity and the A-dependence of the measured yields are determined and compared with the results of other fixed-target experiments and with the available theoretical estimates. Finally, we also address some issues concerning the transverse momentum distributions of the measured dimuons.Comment: 18 pages, 9 figures, to be published in Phys. Lett.

    J/psi azimuthal anisotropy relative to the reaction plane in Pb-Pb collisions at 158 GeV per nucleon

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    The J/ψ\psi azimuthal distribution relative to the reaction plane has been measured by the NA50 experiment in Pb-Pb collisions at 158 GeV/nucleon. Various physical mechanisms related to charmonium dissociation in the medium created in the heavy ion collision are expected to introduce an anisotropy in the azimuthal distribution of the observed J/ψ\psi mesons at SPS energies. Hence, the measurement of J/ψ\psi elliptic anisotropy, quantified by the Fourier coefficient v2_2 of the J/ψ\psi azimuthal distribution relative to the reaction plane, is an important tool to constrain theoretical models aimed at explaining the anomalous J/ψ\psi suppression observed in Pb-Pb collisions. We present the measured J/ψ\psi yields in different bins of azimuthal angle relative to the reaction plane, as well as the resulting values of the Fourier coefficient v2_{2} as a function of the collision centrality and of the J/ψ\psi transverse momentum. The reaction plane has been estimated from the azimuthal distribution of the neutral transverse energy detected in an electromagnetic calorimeter. The analysis has been performed on a data sample of about 100 000 events, distributed in five centrality or pT_{\rm T} sub-samples. The extracted v2_{2} values are significantly larger than zero for non-central collisions and are seen to increase with pT_{\rm T}.Comment: proceedings of HP08 conference corrected a typo in one equatio

    A new measurement of J/psi suppression in Pb-Pb collisions at 158 GeV per nucleon

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    We present a new measurement of J/psi production in Pb-Pb collisions at 158 GeV/nucleon, from the data sample collected in year 2000 by the NA50 Collaboration, under improved experimental conditions with respect to previous years. With the target system placed in vacuum, the setup was better adapted to study, in particular, the most peripheral nuclear collisions with unprecedented accuracy. The analysis of this data sample shows that the (J/psi)/Drell-Yan cross-sections ratio measured in the most peripheral Pb-Pb interactions is in good agreement with the nuclear absorption pattern extrapolated from the studies of proton-nucleus collisions. Furthermore, this new measurement confirms our previous observation that the (J/psi)/Drell-Yan cross-sections ratio departs from the normal nuclear absorption pattern for semi-central Pb-Pb collisions and that this ratio persistently decreases up to the most central collisions.Comment: 19 pages, 10 figures. Submitted to Eur. Phys. J.

    The dependence of the anomalous J/psi suppression on the number of participant nucleons

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    The observation of an anomalous J/psi suppression in Pb-Pb collisions by the NA50 Collaboration can be considered as the most striking indication for the deconfinement of quarks and gluons at SPS energies. In this Letter, we determine the J/psi suppression pattern as a function of the forward hadronic energy E-ZDC measured in a Zero Degree Calorimeter (ZDC). The direct connection between EZDC and the geometry of the collision allows us to calculate, within a Glauber approach, the precise relation between the number of participant nucleons N-part and E-ZDC. Then, we check if the experimental data can be better explained by a sudden or a smooth onset of the anomalous J/psi suppression as a function of the number of participants. (C) 2001 Elsevier Science B.V. All rights reserved.info:eu-repo/semantics/publishedVersio
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