357 research outputs found

    Evaluation de l'impact bioclinique et social, individuel et collectif, du traitement ARV chez des patients VIH-1 pris en charge depuis 10 ans dans le cadre de l'ISAARV : cohorte ANRS 1215 : rapport final

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    This report presents the results from studies conducted between 2009 and 2011 in Senegal in the framework of the ANRS 1215 research program aimed at documenting the long-term impact of therapeutic treatment with antiretroviral drugs. The 400 participants from ANRS cohort 1215 began treatment between 1998 and 2002; they were among the first people living with HIV in Africa to receive ARV therapies. These studies were conducted using a multidisciplinary approach. The main themes are: - Medical science: immune restoration among patients who were the most immunocompromised, virologic failure and resistance mutations, changes in treatment efficacy and mortality, a description of comorbidities, an investigation of the effects of aging, and sexual health. - Public health and epidemiology: changes in treatment adherence, socioeconomic outcomes for patients, sociomedical conditions and determinants for treatment failure, and mental health. - Social sciences: patient's experience of the disease and treatment over the long term, social aspects of childbearing for HIV-positive women on ARVs, perceptions and practices related to prevention of sexual transmission of HIV for patients on ARVs, perceptions of lipodystrophy, vulnerability among widows and the aged, critical analysis of the degree of stigmatization, cost analysis of treatment and drugs, and systems for ethical research. Each of these themes led to specific, often overlapping, studies that used a complementary approach. This report is organized into five sections, with a standardized format for writing conventions, presentation, and bylines, according to the uses in the dominant disciplinary field for each part.Ce rapport rassemble les résultats des études réalisées entre 2009 et 2011 au Sénégal dans le cadre du programme de recherche ANRS 1215 qui avait pour objectif de documenter l'impact à long terme de la prise en charge thérapeutique par les médicaments antirétroviraux. Les 400 participants de la cohorte ANRS 1215 ont débuté leur traitement entre 1998 et 2002, ils font partie des premières personnes vivant avec le VIH en Afrique à avoir reçu des traitements ARV. Ces études ont été menées dans une perspective pluridisciplinaire. Les principales thématiques sont : - en sciences médicales : la restauration immunologique chez les patients les plus immunodéprimés, les échecs virologiques et les mutations de résistances, l'évolution de l'efficacité thérapeutique et de la mortalité, la description des co-morbidités, l'étude des effets du vieillissement, et la santé sexuelle. - en santé publique et épidémiologie : l'évolution de l'observance thérapeutique, le devenir socio-économique des patients, les conditions et déterminants socio-médicaux des échecs thérapeutiques, la santé mentale. - en sciences sociales : l'expérience de la maladie et du traitement à long terme, les aspects sociaux de la procréation chez les femmes vivant avec le VIH traitées par ARV, les perceptions et pratiques relatives à la prévention de la transmission sexuelle du VIH chez les patients traités par ARV, la perception des lipodystrophies, la vulnérabilité des veuves et des personnes âgées, l'analyse critique de la mesure de la stigmatisation, l'étude des coûts de prise en charge et des médicaments, les dispositifs éthiques de la recherche. Chacun de ces thèmes a conduit à des investigations spécifiques, le plus souvent associées, dans des approches visant la complémentarité. Ce rapport est organisé en cinq parties, ayant une cohérence interne au plan des conventions de rédaction, de présentation et de signatures, suivant les usages des champs disciplinaires dominants dans chaque partie

    Quenched BKB_K-parameter with the Wilson and Clover actions at β=6.0\beta = 6.0

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    We present results for the Kaon BB parameter from a sample of 200200 configurations using the Wilson action and 460460 configurations using the Clover action, on a 183×6418^3 \times 64 lattice at β=6.0\beta=6.0. A slight improvement of the chiral behaviour of BKB_K is observed due to the Clover action. We have also compared the results for BKB_K obtained from two different procedures for the boosting of the coupling constant gg. We observe a strong dependence of BKB_K on the prescription adopted for gg in the Wilson case, contrary to the results of the Clover case which are almost unaffected by the choice of gg. Combining some recently obtained non perturbative estimates for the renormalisation constants with our Clover matrix element, we observe a significant improvement in the chiral behaviour of BKB_K.Comment: 3 pages, Latex, Postscript file with figures available at ftp://hpteo.roma1.infn.it/pub/preprints/lat94/donini ; to appear in Lattice '94, Nucl. Phys. (Proc.Suppl.

    Critical coupling for dynamical chiral-symmetry breaking with an infrared finite gluon propagator

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    We compute the critical coupling constant for the dynamical chiral-symmetry breaking in a model of quantum chromodynamics, solving numerically the quark self-energy using infrared finite gluon propagators found as solutions of the Schwinger-Dyson equation for the gluon, and one gluon propagator determined in numerical lattice simulations. The gluon mass scale screens the force responsible for the chiral breaking, and the transition occurs only for a larger critical coupling constant than the one obtained with the perturbative propagator. The critical coupling shows a great sensibility to the gluon mass scale variation, as well as to the functional form of the gluon propagator.Comment: 19 pages, latex, 3 postscript figures, uses epsf.sty and epsf.tex. To be published in Phys. Lett.

    Infrared finite solutions for the gluon propagator and the QCD vacuum energy

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    Nonperturbative infrared finite solutions for the gluon polarization tensor have been found, and the possibility that gluons may have a dynamically generated mass is supported by recent Monte Carlo simulation on the lattice. These solutions differ among themselves, due to different approximations performed when solving the Schwinger-Dyson equations for the gluon polarization tensor. Only approximations that minimize energy are meaningful, and, according to this, we compute an effective potential for composite operators as a function of these solutions in order to distinguish which one is selected by the vacuum.Comment: 16 pages, latex file, 1 postscript figure, uses epsf.sty and axodraw.sty. To be published in Phys. Lett.

    Compatibility of a model for the QCD-Pomeron and chiral-symmetry breaking phenomenologies

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    The phenomenology of a QCD-Pomeron model based on the exchange of a pair of non-perturbative gluons, i.e. gluon fields with a finite correlation length in the vacuum, is studied in comparison with the phenomenology of QCD chiral symmetry breaking, based on non-perturbative solutions of Schwinger-Dyson equations for the quark propagator including these non-perturbative gluon effects. We show that these models are incompatible, and point out some possibles origins of this problem.Comment: 21 pages, uuencoded latex file, 3 postscript figures, uses epsf.sty and epsf.tex. To be published in Phys. Lett.

    A real-time non-linear vehicle preview model

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    Vehicle accident statistics indicate that fatalities due to rollover of sport utility vehicles (SUVs) are of international concern. Soft suspension, combined with high centre-of-gravity, increase SUV rollover propensity. Control strategies for prevention or mitigation of rollover, based on the current state of the vehicle, exist but most experience a delay in switching, due to response times of the controllers and actuators used to control vehicles dynamics. This paper proposes a real-time non-linear vehicle preview model (VPM) capable of accurately predicting future vehicle states based on current states. The preview model is developed and experimentally validated on a SUV. Results indicate that important vehicle states, including roll angle and lateral acceleration, can be accurately predicted up to more than 0.25 s into the future. Vehicle dynamics controllers can use the previewed states instead of the measured states to eliminate delays and make the strategies proactive instead of reactive.https://www.inderscienceonline.com/loi/ijhvs?expanded=252019-03-01hj2018Materials Science and Metallurgical Engineerin

    A lattice study of the exclusive BKγB \to K^* \gamma decay amplitude, using the Clover action at β=6.0\beta=6.0

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    We present the results of a numerical calculation of the BKγB\to K^* \gamma form factors. The results have been obtained by studying the relevant correlation functions at β=6.0\beta=6.0, on an 183×6418^3 \times 64 lattice, using the O(a){\rm O(a)}-improved fermion action, in the quenched approximation. From the study of the matrix element we have obtained the form factor T1(0)T_1(0) which controls the exclusive decay rate. The results are compared with the recent results from CLEO. We also discuss the compatibility between the scaling laws predicted by the Heavy Quark Effective Theory (HQET) and pole dominance, by studying the mass- and q2q^2-dependence of the form factors. From our analysis, it appears that the form factors follow a mass behaviour compatible with the predictions of the HQET and that the q2q^2-dependence of T2T_2 is weaker than would be predicted by pole dominance.Comment: 17 pages, LaTeX + epsf.sty. Uuencoded, compressed, tar archive including the text and one postscript figur

    Superfield T-duality rules

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    A geometric treatment of T-duality as an operation which acts on differential forms in superspace allows us to derive the complete set of T-duality transformation rules which relate the superfield potentials of D=10 type IIA supergravity with those of type IIB supergravity including Ramond-Ramond superfield potentials and fermionic supervielbeins. We show that these rules are consistent with the superspace supergravity constraints.Comment: 24 pages, latex, no figures. V2 misprints corrected. V3. One reference ([30]) and a comment on it ('Notice added') on p. 19 adde
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