357 research outputs found
Approximation methods for nonlinear filtering problems arising in system identification (summary)
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
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 -parameter with the Wilson and Clover actions at
We present results for the Kaon parameter from a sample of
configurations using the Wilson action and configurations using the
Clover action, on a lattice at . A slight
improvement of the chiral behaviour of is observed due to the Clover
action. We have also compared the results for obtained from two different
procedures for the boosting of the coupling constant . We observe a strong
dependence of on the prescription adopted for in the Wilson case,
contrary to the results of the Clover case which are almost unaffected by the
choice of . 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 .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
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
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
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
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 decay amplitude, using the Clover action at
We present the results of a numerical calculation of the
form factors. The results have been obtained by studying the relevant
correlation functions at , on an lattice, using the
-improved fermion action, in the quenched approximation. From the
study of the matrix element we have
obtained the form factor 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 -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
-dependence of 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
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
- …