998 resultados para Recherche lin


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Avant même d'entamer ma recherche de sujet pour le travail de maîtrise, j'avais déjà une certitude: je souhaitais choisir un thème qui m'intéressait, certes, mais surtout qui arriverait à me passionner, de façon à pouvoir y mettre toute mon énergie. Le choix initial de m'orienter vers ma future spécialité, la psychiatrie, s'est vite confirmé, et un rayon de l'IUMG en particulier a très rapidement attiré ma curiosité: celui de l'ethnopsychiatrie. Pour le choix du thème de ce travail, mon expérience de vie, suite à un mariage mixte, et mon inté- rêt pour les migrants, ont compté, ainsi que les nombreux stages effectués en milieux multicultu- rels et ma probable future orientation en psychiatrie systémique. Face à l'augmentation de la migration et des déplacements des populations et des individus ainsi qu'aux mélanges interculturels qui en résultent, les recherches transculturelles connaissent, depuis quelques années, un développement important: ceci est valable en psychiatrie, en psychopathologie comme en psychothérapie. Pendant mes stages, j'ai remarqué que l'accueil et la prise en charge des personnes étrangères sont une possibilité, pour les professionnels issus de tous les domaines, que ce soit d'un milieu médico- psychologique, social ou éducatif, de remettre en cause les méthodes théoriques et techniques habi- tuelles. En effet, dès que l'on est amené à s'occuper de personnes d'une culture différente de la nô- tre, une partie de nos théories, de notre manière d'intervention clinique et de nos principes de for- mation se trouve forcément remise en question. Le choix de mieux connaître et proposer cette nouvelle discipline par un travail de master s'est basé également en fonction de l'ampleur du parcours historique que l'ethnopsychiatrie nous permettait d'explorer. Par mon travail, j'ai donc essayé de retracer le parcours socio-historique de l'ethnopsychiatrie de- puis ses origines. Cela n'a pas été facile car, même si théoriquement cette discipline s'est dévelop- pée aux alentours du début du XXe siècle, entre l'Europe et les lieux où l'Occident élargissait son domaine, il n y a pas unanimité sur un fondateur précis. Cependant, à plusieurs reprises, Emil Kraepelin est cité comme le fondateur de cette discipline, et c'est pour cette raison que j'ai décidé de focaliser mon attention sur ce grand psychiatre, pour es- sayer de comprendre pourquoi plusieurs auteurs le considèrent comme le père de l'ethnopsychia- trie. Pour ce faire, dans une première partie, ma recherche a donc consisté en une revue de la littérature médicale spécialisée. 4 Je me suis basée tout d'abord sur des sources primaires, en cherchant des articles écrits par Kraepe- lin lui-même, consultant principalement les revues germanophones et anglo-saxonnes susceptibles d'avoir publié ses articles. J'ai également consulté un choix de traités de psychiatrie qu'il a publié. Dans la deuxième partie de mes recherches, j'ai passé en revue la littérature secondaire, en me ba- sant sur des articles qui ont été écrits sur lui par différents auteurs, psychiatres et historiens. La thè- se du Dr. Christoph Bendick a été utilisée en particulier: «Emil Kraepelin's Forschungsreise nach Java», a été un outil précieux pour retrouver aussi bien des récits primaires inédits du psychiatre que maintes sources de littérature secondaire. En analysant cette littérature, j'ai essayé de dégager les principaux thèmes d'évolution entre le XIXe et le XXe siècle, en cherchant en parallèle d'éventuelles répercussions des travaux de psy- chiatrie comparée du médecin allemand sur la postérité, ainsi que sur la psychiatrie moderne. En progressant dans mon travail, je me suis pertinemment posé la question suivante: Kraepelin était-il vraiment le premier qui se fut intéressé à une psychiatrie « exotique » ou, au contraire, l'ambition de comparer la folie occidentale à des peuples et civilisations étrangers avait-elle déjà commencé bien avant lui ? Aurait-il apporté quelque chose de différent dans sa recherche, qui nous permettrait aujourd'hui de lui attribuer le statut de fondateur de l'ethnopsychiatrie ? Afin d'essayer de répondre à cette réflexion, ma méthodologie a consisté en un dépouillement d'une célèbre revue de psychiatrie française, Les annales médico-psychologiques, depuis le premier numéro paru en 1843 jusqu'à l'aube de la deuxième guerre mondiale, à la recherche d'articles trai- tant de la folie exotique. Pour accomplir cette tâche, un article de R. Collignon, psychologue-anthropologue travaillant sur l'histoire de la psychiatrie en Afrique, m'a été d'une aide très précieuse. Ce texte, paru dans la re- vue Psychopathologie Africaine, qui répertorie tous les articles traitants de la psychiatrie coloniale, m'a évité de devoir analyser personnellement toute la collection des A.M.P., ce qui a permis un gain de temps considérable. Une analyse approfondie de cette littérature m'a permis de me forger une idée sur la question et de dégager en même temps, dans la troisième partie du travail, les principaux thèmes d'évolution en ethnopsychiatrie entre le XIXe et le XXe siècle. Finalement, en disséquant les théories d'un autre auteur qui s'est passionné pour l'ethnopsychiatrie, le psychanalyste Georges Devereux, considéré également comme le fondateur de cette discipline, j'ai essayé de comprendre les changements qui se sont opérés dans ce domaine pendant la période qui les sépare. Un regard particulier a été porté sur les possibles répercussions de l'ancienne eth- nopsychiatrie, de connotation coloniale, sur une ethnopsychiatrie plus «moderne», laquelle, suite aux travaux de Devereux, a évolué depuis quelques années surtout dans les domaines des études de la migration et de l'intégration. 5 Cette ethnopsychiatrie contemporaine inclut aujourd'hui des phénomènes uniques attribués à une origine culturelle qui, depuis 1995, sont regroupés dans le DSM IV sous le nom de Culture-Bound Syndromes. Ce travail de master esquisse donc un double mouvement: Europe-Occident, Occident-Europe. Sur ce chemin, aux alentours de 1900, sont posés les premières grandes lignes et récits d'une ethnopsy- chiatrie, née en un premier temps entre l'Europe et ses colonies et ensuite entre l'Europe et le reste du monde.

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Three-particle azimuthal correlation measurements with a high transverse momentum trigger particle are reported for pp, d + Au, and Au + Au collisions at root(S)NN = 200 GeV by the STAR experiment. Dijet structures are observed in pp, d + Au and peripheral Au + Au collisions. An additional structure is observed in central Au + Au data, signaling conical emission of correlated charged hadrons. The conical emission angle is found to be theta = 1.37 +/- 0.02(stat)(-0.07)(+0.06)(syst), independent of p perpendicular to.

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We present measurements of net charge fluctuations in Au+Au collisions at s(NN)=19.6, 62.4, 130, and 200 GeV, Cu+Cu collisions at s(NN)=62.4 and 200 GeV, and p+p collisions at s=200 GeV using the dynamical net charge fluctuations measure nu(+-,dyn). We observe that the dynamical fluctuations are nonzero at all energies and exhibit a modest dependence on beam energy. A weak system size dependence is also observed. We examine the collision centrality dependence of the net charge fluctuations and find that dynamical net charge fluctuations violate 1/N(ch) scaling but display approximate 1/N(part) scaling. We also study the azimuthal and rapidity dependence of the net charge correlation strength and observe strong dependence on the azimuthal angular range and pseudorapidity widths integrated to measure the correlation.

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We measure directed flow (v(1)) for charged particles in Au + Au and Cu + Cu collisions at root s(NN) = 200 and 62.4 GeV, as a function of pseudorapidity (eta), transverse momentum (p(t)), and collision centrality, based on data from the STAR experiment. We find that the directed flow depends on the incident energy but, contrary to all available model implementations, not on the size of the colliding system at a given centrality. We extend the validity of the limiting fragmentation concept to v(1) in different collision systems, and investigate possible explanations for the observed sign change in v(1)(p(t)).

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We report precision measurements of the Feynman x (x(F)) dependence, and first measurements of the transverse momentum (p(T)) dependence, of transverse single-spin asymmetries for the production of pi(0) mesons from polarized proton collisions at s=200 GeV. The x(F) dependence of the results is in fair agreement with perturbative QCD model calculations that identify orbital motion of quarks and gluons within the proton as the origin of the spin effects. Results for the p(T) dependence at fixed x(F) are not consistent with these same perturbative QCD-based calculations.

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We report on the observed differences in production rates of strange and multistrange baryons in Au+Au collisions at s(NN)=200 GeV compared to p+p interactions at the same energy. The strange baryon yields in Au+Au collisions, when scaled down by the number of participating nucleons, are enhanced relative to those measured in p+p reactions. The enhancement observed increases with the strangeness content of the baryon, and it increases for all strange baryons with collision centrality. The enhancement is qualitatively similar to that observed at the lower collision energy s(NN)=17.3 GeV. The previous observations are for the bulk production, while at intermediate p(T),1 < p(T)< 4 GeV/c, the strange baryons even exceed binary scaling from p+p yields.

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The contribution of B meson decays to nonphotonic electrons, which are mainly produced by the semileptonic decays of heavy-flavor mesons, in p + p collisions at root s = 200 GeV has been measured using azimuthal correlations between nonphotonic electrons and hadrons. The extracted B decay contribution is approximately 50% at a transverse momentum of p(T) >= 5 GeV/c. These measurements constrain the nuclear modification factor for electrons from B and D meson decays. The result indicates that B meson production in heavy ion collisions is also suppressed at high p(T).

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We report on K*(0) production at midrapidity in Au + Au and Cu + Cu collisions at root s(NN) = 62.4 and 200 GeV collected by the Solenoid Tracker at the Relativistic Heavy Ion Collider detector. The K*(0) is reconstructed via the hadronic decays K*(0) -> K(+)pi(-) and (K*(0)) over bar -> K(+)pi(-). Transverse momentum, p(T), spectra are measured over a range of p(T) extending from 0.2 GeV/c up to 5 GeV/c. The center-of-mass energy and system size dependence of the rapidity density, dN/dy, and the average transverse momentum, < p(T)>, are presented. The measured N(K*(0))/N(K) and N(phi)/N(K*(0)) ratios favor the dominance of rescattering of decay daughters of K*(0) over the hadronic regeneration for the K*(0) production. In the intermediate p(T) region (2.0 < p(T) < 4.0 GeV/c), the elliptic flow parameter, v(2), and the nuclear modification factor, R(CP), agree with the expectations from the quark coalescence model of particle production.

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Charged-particle spectra associated with direct photon (gamma(dir)) and pi(0) are measured in p + p and Au + Au collisions at center-of-mass energy root(S)(NN) = 200 GeV with the STAR detector at the Relativistic Heavy Ion Collider. A shower-shape analysis is used to partially discriminate between gamma(dir) and pi(0). Assuming no associated charged particles in the gamma(dir) direction ( near side) and small contribution from fragmentation photons (gamma(frag)), the associated charged-particle yields opposite to gamma(dir) (away side) are extracted. In central Au + Au collisions, the charged-particle yields at midrapidity (vertical bar eta vertical bar < 1) and high transverse momentum (3 < (assoc)(PT) < 16 GeV/c) associated with gamma(dir) and pi(0) (vertical bar eta vertical bar < 0.9, 8 < (trig)(PT) < 16 GeV/c) are suppressed by a factor of 3-5 compared with p + p collisions. The observed suppression of the associated charged particles is similar for gamma(dir) and pi(0) and independent of the gamma(dir) energy within uncertainties. These measurements indicate that, in the kinematic range covered and within our current experimental uncertainties, the parton energy loss shows no sensitivity to the parton initial energy, path length, or color charge.

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Yields, correlation shapes, and mean transverse momenta p(T) of charged particles associated with intermediate-to high-p(T) trigger particles (2.5 < p(T) < 10 GeV/c) in d + Au and Au + Au collisions at root s(NN) = 200 GeV are presented. For associated particles at higher p(T) greater than or similar to 2.5 GeV/c, narrow correlation peaks are seen in d + Au and Au + Au, indicating that the main production mechanism is jet fragmentation. At lower associated particle pT < 2 GeV/c, a large enhancement of the near- (Delta phi similar to 0) and away-side (Delta phi similar to pi) associated yields is found, together with a strong broadening of the away-side azimuthal distributions in Au + Au collisions compared to d + Au measurements, suggesting that other particle production mechanisms play a role. This is further supported by the observed significant softening of the away-side associated particle yield distribution at Delta phi similar to pi in central Au + Au collisions.

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Balance functions have been measured for charged-particle pairs, identified charged-pion pairs, and identified charged-kaon pairs in Au + Au, d + Au, and p + p collisions at root s(NN) = 200 GeV at the Relativistic Heavy Ion Collider using the STAR detector. These balance functions are presented in terms of relative pseudorapidity, Delta eta, relative rapidity, Delta y, relative azimuthal angle, Delta phi, and invariant relative momentum, q(inv). For charged-particle pairs, the width of the balance function in terms of Delta eta scales smoothly with the number of participating nucleons, while HIJING and UrQMD model calculations show no dependence on centrality or system size. For charged-particle and charged-pion pairs, the balance functions widths in terms of Delta eta and Delta y are narrower in central Au + Au collisions than in peripheral collisions. The width for central collisions is consistent with thermal blast-wave models where the balancing charges are highly correlated in coordinate space at breakup. This strong correlation might be explained by either delayed hadronization or limited diffusion during the reaction. Furthermore, the narrowing trend is consistent with the lower kinetic temperatures inherent to more central collisions. In contrast, the width of the balance function for charged-kaon pairs in terms of Delta y shows little centrality dependence, which may signal a different production mechanism for kaons. The widths of the balance functions for charged pions and kaons in terms of q(inv) narrow in central collisions compared to peripheral collisions, which may be driven by the change in the kinetic temperature.

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We report on a measurement of the gamma(1S + 2S + 3S) -> e(+)e(-) cross section at midrapidity in p + p collisions at root s = 200 GeV. We find the cross section to be 114 +/- 38(stat + fit)(-24)(+23)(syst) pb. Perturbative QCD calculations at next-to-leading order in the color evaporation model are in agreement with our measurement, while calculations in the color singlet model underestimate it by 2 sigma. Our result is consistent with the trend seen in world data as a function of the center-of-mass energy of the collision and extends the availability of gamma data to RHIC energies. The dielectron continuum in the invariant-mass range near the gamma is also studied to obtain a combined yield of e(+)e(-) pairs from the sum of the Drell-Yan process and b-(b) over bar production.

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We report the first three-particle coincidence measurement in pseudorapidity (Delta eta) between a high transverse momentum (p(perpendicular to)) trigger particle and two lower p(perpendicular to) associated particles within azimuth |Delta phi| < 0.7 in root s(NN) = 200 GeV d + Au and Au + Au collisions. Charge ordering properties are exploited to separate the jetlike component and the ridge (long range Delta eta correlation). The results indicate that the correlation of ridge particles are uniform not only with respect to the trigger particle but also between themselves event by event in our measured Delta eta. In addition, the production of the ridge appears to be uncorrelated to the presence of the narrow jetlike component.

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We report new results on identified (anti) proton and charged pion spectra at large transverse momenta (3 < p(T) < 10 GeV/c) from Cu + Cu collisions at root s(NN) = 200 GeV using the STAR detector at the Relativistic Heavy Ion Collider (RHIC). This study explores the system size dependence of two novel features observed at RHIC with heavy ions: the hadron suppression at high-p(T) and the anomalous baryon to meson enhancement at intermediate transverse momenta. Both phenomena could be attributed to the creation of a new form of QCD matter. The results presented here bridge the system size gap between the available pp and Au + Au data, and allow for a detailed exploration of the onset of the novel features. Comparative analysis of all available 200 GeV data indicates that the system size is a major factor determining both the magnitude of the hadron spectra suppression at large transverse momenta and the relative baryon to meson enhancement.

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We present the results of an elliptic flow, v(2), analysis of Cu + Cu collisions recorded with the solenoidal tracker detector (STAR) at the BNL Relativistic Heavy Ion Collider at root s(NN) = 62.4 and 200 GeV. Elliptic flow as a function of transverse momentum, v(2)(p(T)), is reported for different collision centralities for charged hadrons h(+/-) and strangeness-ontaining hadrons K(S)(0), Lambda, Xi, and phi in the midrapidity region vertical bar eta vertical bar < 1.0. Significant reduction in systematic uncertainty of the measurement due to nonflow effects has been achieved by correlating particles at midrapidity, vertical bar eta vertical bar < 1.0, with those at forward rapidity, 2.5 < vertical bar eta vertical bar < 4.0. We also present azimuthal correlations in p + p collisions at root s = 200 GeV to help in estimating nonflow effects. To study the system-size dependence of elliptic flow, we present a detailed comparison with previously published results from Au + Au collisions at root s(NN) = 200 GeV. We observe that v(2)(p(T)) of strange hadrons has similar scaling properties as were first observed in Au + Au collisions, that is, (i) at low transverse momenta, p(T) < 2 GeV/c, v(2) scales with transverse kinetic energy, m(T) - m, and (ii) at intermediate p(T), 2 < p(T) < 4 GeV/c, it scales with the number of constituent quarks, n(q.) We have found that ideal hydrodynamic calculations fail to reproduce the centrality dependence of v(2)(p(T)) for K(S)(0) and Lambda. Eccentricity scaled v(2) values, v(2)/epsilon, are larger in more central collisions, suggesting stronger collective flow develops in more central collisions. The comparison with Au + Au collisions, which go further in density, shows that v(2)/epsilon depends on the system size, that is, the number of participants N(part). This indicates that the ideal hydrodynamic limit is not reached in Cu + Cu collisions, presumably because the assumption of thermalization is not attained.