Interplay of dust alignment, grain growth and magnetic fields in polarization: lessons from the emission-to-extinction ratio

Polarized extinction and emission from dust in the interstellar medium (ISM) are hard to interpret, as they have a complex dependence on dust optical properties, grain alignment and magnetic field orientation. This is particularly true in molecular clouds. The data available today are not yet used to their full potential. The combination of emission and extinction, in particular, provides information not available from either of them alone. We combine data from the scientific literature on polarized dust extinction with Planck data on polarized emission and we use them to constrain the possible variations in dust and environmental conditions inside molecular clouds, and especially translucent lines of sight, taking into account magnetic field orientation. We focus on the dependence between \lambda_max -- the wavelength of maximum polarization in extinction -- and other observables such as the extinction polarization, the emission polarization and the ratio of the two. We set out to reproduce these correlations using Monte-Carlo simulations where the relevant quantities in a dust model -- grain alignment, size distribution and magnetic field orientation -- vary to mimic the diverse conditions expected inside molecular clouds. None of the quantities chosen can explain the observational data on its own: the best results are obtained when all quantities vary significantly across and within clouds. However, some of the data -- most notably the stars with low emission-to-extinction polarization ratio -- are not reproduced by our simulation. Our results suggest not only that dust evolution is necessary to explain polarization in molecular clouds, but that a simple change in size distribution is not sufficient to explain the data, and point the way for future and more sophisticated models

The Effect of Coach's Task- and Ego-Involving Climate on the Changes in Perceived Competence, Relatedness, and Autonomy Among Girl Handballers

International audienceAdolescents, especially females, have been identified as a group at risk of poor health due to their declining level of physical activity. To prevent sporting attrition, several researchers highlighted the importance of the fit between the motivational context provided by the coach and the socio-emotional needs brought by adolescents. This study concerns the role of the coach's task- and ego-involving climate on the changes in 3 fundamental perceptions underlined by the self-determination theory (8): perceived competence, autonomy, and relatedness. Contrary to the cross-sectional nature of the former studies, this one used longitudinal survey data from 236 French girl handballers. The 3 perceptions were measured by a questionnaire at the beginning and the end of one season. In the middle of the season, perceptions of coaches' motivational climate were also evaluated. Results showed that at the end of the season, feelings of competence, autonomy, and relatedness were both positively predicted by a task-involving climate and negatively predicted by an ego-involving climate, even after controlling for the level of each variable at the beginning of the season

Dominique KALIFA et Pierre KARILA-COHEN [dir.], Le commissaire de police au XIXe siècle

Une figure méconnue et équivoque : tel apparaît le commissaire de police du XIXe siècle. Dédaigné par le roman ou le récit policier, qui lui préfèrent la figure de l’inspecteur, ce personnage, né avec la Révolution, pâtit d’une réputation exécrable parmi ses contemporains. Arrogance, incurie, incompétence caractérisent le petit notable, touché par deux syndromes : le syndrome Fouché qui en fait un agent provocateur au service d’un État oppresseur, et le syndrome Vidocq qui le place à la front..

Dominique KALIFA et Pierre KARILA-COHEN [dir.], Le commissaire de police au XIXe siècle

Une figure méconnue et équivoque : tel apparaît le commissaire de police du XIXe siècle. Dédaigné par le roman ou le récit policier, qui lui préfèrent la figure de l’inspecteur, ce personnage, né avec la Révolution, pâtit d’une réputation exécrable parmi ses contemporains. Arrogance, incurie, incompétence caractérisent le petit notable, touché par deux syndromes : le syndrome Fouché qui en fait un agent provocateur au service d’un État oppresseur, et le syndrome Vidocq qui le place à la front..

L’honneur en partage. Le duel et les classes bourgeoises en France au XIXe siècle

Symbole de l’éthique nobiliaire, le duel continue d’être pratiqué en un siècle traditionnellement considéré comme celui de la domination bourgeoise et sous un régime d’égalité civile. Interprétée par les contemporains comme une imitation de la vieille classe dirigeante par celle qui l’a remplacée, cette persistance résulte avant tout de la prégnance du sentiment de l’honneur, qui sert de dénominateur commun à une classe dirigeante composite pendant la première moitié du XIXe siècle, puis constitue une valeur refuge pour des élites marquées par la défaite de 1870. Pour la nouvelle classe dirigeante, le duel relève d’une éthique virile qui gouverne leur vie tout entière, dans ses aspects privés – il est un instrument de défense de la famille, telle qu’elle est définie par le code civil napoléonien – comme dans ses aspects publics, en particulier dans la vie politique. Assagi et rendu peu dangereux, il constitue un utile mode de règlement des conflits dans une société démocratique.As a symbol of the ethics of the nobility, the duel was still practised in a century traditionally considered as that of the bourgeois domination and under a regime of civil equality. Interpreted by the contemporaries as an imitation of the old ruling class by the one who replaced it, this persistence resulted above all from the importance of the sentiment of honour, which was used as a common denominator for a composite ruling class during the first half of the nineteenth century. It was then a refuge value for the elite marked by the 1870 defeat. For the new ruling class, the duel concerned virile ethics which governed their whole life, in its private aspects—it was an instrument of defence of the family, such as she was defined by the Napoleonic civil code—as in its public aspects, in particular in the politics. Quietened down and made less dangerous, it was a useful method to settle conflicts in a democratic society

Analyse comparative entre Schelling et Kierkegaard sur la question du mal

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Perturbations of the CD8+ T-cell repertoire in CVID patients with complications

AbstractA higher chronic expansion of effector cytotoxic CD8+DR+ T-lymphocytes has been reported in common variable immunodeficiency (CVID) patients with complications such as splenomegaly, autoimmune disease and/or granulomatous disease. In order to document the features associated with this T cell activation involving the CD8+ T-compartment, we examined the diversity of the alpha/beta TCR repertoire of the patient's CD8+ T-lymphocytes using the qualitative analysis of the CDR3 lengths (Immunoscope).Ten CIVD patients were enrolled in this study, four without complications (Group 1), six with complications (Group 2). All patients exhibited non-gaussian altered CDR3 length distributions, albeit to different extent within the different Vβ families. CVID patients with activated CD8+ T-cells show a reduction of their TCR repertoire diversity which is more severe in patients with complications. Viral reactivations such as CMV are suspected to be part of the mechanisms underlying immunosenescence

Motivation and Dropout in Female Handballers: A 21-month Prospective Study

International audienceThe purpose of this study was to test a motivational model of sport dropout that integrates the 4 stage-causal sequence proposed by the Hierarchical Model of Vallerand (1997) and elements from achievement goal theory (Nicholls, 1989). The model posits that a task involving motivational climate facilitates, while an ego-involving climate undermines, perceptions of competence, autonomy, and relatedness. In turn, feeling incompetent, non autonomous, and unrelated to others undermines self-determined motivation toward handball which leads to the intention of dropping out of handball. Finally, such intentions are implemented later on. Three-hundred and thirty-five females handballers completed a motivation questionnaire and were followed for 21-months. Results from structural equation modeling analyses provided basic support for the model. Findings are discussed in light of their theoretical and applied implications

Predicting persistence or withdrawal in female handballers with Social Exchange theory

International audienceTwo complementary studies were conducted to explain the dropout phenomenon with French female handball players, utilizing the tenets of social exchange theory (Thibaut & Kelley, 1959; Rusbult, 1980). In the first study, the aim was to more fully explore the sources of enjoyment by emphasizing the key variables in the costs/benefits analysis. We postulate that the costs/benefits analysis consists in each athlete estimating the probability of reaching the most desired consequences for him or her (e.g., learn and improve skill, affiliation with others, be better than the others). The subjects were 488 French women aged from 15-19 years. Structural equation modeling (SEM) revealed that enjoyment in handball was predicted by a latent variable (named perceived benefits) subjacent to perceptions of competence, autonomy, relatedness, progress, coach's support, and time of play. In the second study, we tested a sport commitment model based on the social exchange postulates, using SEM analyses and a prospective design over 8 months. In view of the results of study 1, we replaced the construct of enjoyment with perceived benefit. This analysis provides a more comprehensive understanding of the enjoyment construct and is more consistent with the notion of cost and benefits outlined in social exchange theory (Thibaut and Kelley, 1959). Participants were 253 French handball players between the ages of 14 and 16 years. A first set of analyses, focused on the differences, showed that dropout players perceived themselves as significantly less competent, less autonomous, less related to their team, lower in progress and less supported by their coach than persistent players. The second set of analyses with SEM revealed that the commitment level was positively associated with perceived benefits and negatively with social constraints and alternatives opportunities. Finally, a lack of commitment led to dropping out of the sport 8-months later.Deux études complémentaires destinée à mieux comprendre le phénomène de l'abandon chez des handballeuses françaises à partir des postulats de la théorie de l'échange social (Thibaut & Kelley, 1959; Rusbult, 1980), ont été conduites. La première étude s'est intéressée aux sources du plaisir lié à la pratique sportive. Nous avons postulé que l'analyse coûts/bénéfices correspondait à une estimation d'atteindre les motifs les plus importants de pratique (e.g., apprendre et progresser, avoir des amis, être meilleur que les autres). Les sujets étaient 488 handballeuses françaises âgées de 15 à 19 ans. Les résultats d'analyses par équations structurelles (AES) ont révélé que le plaisir en handball était prédit par une variable latente (dénommée “bénéfices perçus” dans l'activité) sous jacente aux perceptions de compétence, d'autonomie, d'affiliation, de progrès, du soutien de l'entraîneur, et du temps de jeu moyen en match. Dans la deuxième étude, nous avons testé un modèle de l'engagement sportif basé sur les postulats de la théorie de l'échange social, en utilisant des AES et un suivi longitudinal de 8 mois. Au regard, des résultats de la première étude, nous avons remplacé le construit de plaisir par celui des bénéfices perçus. Cette analyse permet une compréhension plus complète des notions de coûts et de bénéfices développées dans la théorie de l'échange social (Thibaut et Kelley, 1959). Les participants étaient 253 joueuses âgées de 14 à 16 ans. Les résultats ont montré que les joueuses qui avaient abandonné se percevaient moins compétentes, moins autonomes, moins liées à leur équipe, moins en progrès et moins encouragées par leur entraîneur que les joueuses persistantes. De plus, l'AES a révélé que le niveau d'engagement était associé positivement aux bénéfices perçus, et négativement aux contraintes sociales et aux activités alternatives. En retour, un faible niveau d'engagement prédisait un taux élevé d'abandon 8 mois plus tard

PHM survey: implementation of signal processing methods for monitoring bearings and gearboxes

The reliability and safety of industrial equipments are one of the main objectives of companies to remain competitive in sectors that are more and more exigent in terms of cost and security. Thus, an unexpected shutdown can lead to physical injury as well as economic consequences. This paper aims to show the emergence of the Prognostics and Health Management (PHM) concept in the industry and to describe how it comes to complement the different maintenance strategies. It describes the benefits to be expected by the implementation of signal processing, diagnostic and prognostic methods in health-monitoring. More specifically, this paper provides a state of the art of existing signal processing techniques that can be used in the PHM strategy. This paper allows showing the diversity of possible techniques and choosing among them the one that will define a framework for industrials to monitor sensitive components like bearings and gearboxes