Comparison of SUSY spectrum calculations and impact on the relic density constraints from WMAP

We compare results of four public supersymmetric (SUSY) spectrum codes, Isajet, Softsusy, Spheno and Suspect to estimate the present-day uncertainty in the calculation of the relic density of dark matter in mSUGRA models. We find that even for mass differences of about 1% the spread in the obtained relic densities can be 10%. In difficult regions of the parameter space, such as large tan(beta) or large m_0, discrepancies in the relic density are much larger. We also find important differences in the stau co-annihilation region. We show the impact of these uncertainties on the bounds from WMAP for several scenarios, concentrating on the regions of parameter space most relevant for collider phenomenology. We also discuss the case of non-zero A_0 and the stop co-annihilation region. Moreover, we present a web application for the online comparison of the spectrum codes.Comment: 26 pages, 6 figures, 10 tables; version to appear in PR

Pour une amélioration du français chez les garçons

Recherche subventionnée par le ministère de l’Éducation, du Loisir et du Sport du gouvernement du Québec, dans le cadre de son Programme d’aide à la recherche sur l’enseignement et l’apprentissage (PAREA)Contributions iii; Remerciements v; Sommaire vii; Listes des figures et des tableaux xi; Listes des abréviations et des symboles xiii; Introduction 1; Première partie Préalables théoriques et méthodologiques 5; Chapitre 1 Problématique 7; Portrait de Nicolas 8; Définition du problème et état de la question 11; Les garçons et les mesures d’aide en français 20; Objectifs 29; Chapitre 2 Méthodologie 33; Portrait de Juan 34; Devis de recherche 38; Analyse de la situation 39; Ébauche des cahiers de charges et des portraits 40; Conception des objets 48; Préparation technique et construction des prototypes 49; Mise au point des objets 51; Deuxième partie Objets pédagogiques 53; Chapitre 3 Objet pédagogique Au lieu de lire 55; Portrait d’Alessandro 56; Présentation 60; Cahier des charges 63; Mise en oeuvre 74; Évaluation et discussion 88; Chapitre 4 Objet pédagogique Français, futur simple? 109; Portrait de Samuel 110; x; Présentation 113; Cahier des charges 115; Mise en oeuvre 123; Évaluation et discussion 137; Conclusion 145; Portrait de Tristan 158; Bibliographie 163; Annexe 1 Synthèse des résultats du premier temps de la recherche (2000-2003) 173; Annexe 2 Grille de codage préalable 179; Annexe 3 Matrice 189; Annexe 4 Fiches pour les observations de terrain 193; Annexe 5 Tableau de régression extrait de Lapostolle, Massé et Pinho, 2003, p. 91 199; Annexe 6 Tableau de régression extrait de Lapostolle, Massé et Pinho, 2003, p. 87 201; Annexe 7 Corpus français 203; Annexe 8 Ouvrages de référence . 227; Annexe 9 Feuillet parcours + contenu 229; Annexe 10 Feuillet parcours + mesures 233

Utilisation d'une souche indigène de Trichoderma harzianum contre cinq agents pathogènes chez le concombre et la tomate de serre au Québec

Le potentiel antagoniste du biofongicide à base de Trichoderma harzianum MAUL-20, isolé au Québec, a été testé contre cinq agents telluriques phytopathogènes(Fusarium oxysporum f. sp. radicis-lycopersici (FORL), Pythium ultimum, Rhizoctonia solani, Sclerotinia sclerotiorum et Verticillium dahliae) du concombre et de la tomate de serre. Le biofongicide a démontré une efficacité contre P. ultimum et R. solani chez le concombre et la tomate et contre FORL chez la tomate. De plus, T. harzianum MAUL-20 a eu un effet stimulant sur le développement des plants de concombre lorsque cultivés, sans agents pathogènes, dans un substrat organique alimenté du biofongicide. L'efficacité de T. harzianum MAUL-20 a été comparée à celle du biofongicide américain Rootshield™ (Trichoderma harzianum KRL-AG2) et le premier a démontré une activité antagoniste égale ou supérieure à celle de Rootshield™.Trichoderma harzianum MAUL-20, a strain isolated from a soil in the province of Québec, was evaluated for its antagonistic potential against five plant pathogens (Fusarium oxysporum f. sp. radicis-lycopersici (FORL), Pythium ultimum, Rhizoctonia solani, Sclerotinia sclerotiorum, and Verticillium dahliae) on greenhouse cucumber and tomato. It reduced disease incidence significantly against P. ultimum and R. solani on both cucumber and tomato and against FORL on tomato. In addition, T. harzianum MAUL-20 stimulated plant growth of cucumber plants when amended to a substrate without plant pathogens. Its efficacy was compared to that of Rootshield™, a biofungicide based on Trichoderma harzianum KRL-AG2 registered in the USA. Its biocontrol potential was equivalent or superior to Rootshield™

Association between physical activity motives and type of physical activity in children

Abstract: Objectives: Motives for participating in a specific type of physical activity (PA) may differ across PA type in youth. We studied the relationship between PA motives and type of PA engaged in by youth. Design: Cross-sectional analysis using data from the Monitoring Activities of Teenagers to Comprehend their Habits (MATCH) study. Method: 802 students age 10-11 years from 17 primary schools in New-Brunswick, Canada completed a questionnaire that collected data on type of PA participated in (individual, group-based, organized, non-organized), PA motives (enjoyment, social affiliation, competence, fitness/health, appearance) and attainment of PA guidelines (60 minutes of moderate-to-vigorous PA per day). The associations between PA motives and PA type and between PA motives and attainment of PA recommendations were assessed in multilevel logistic regression models. Results: Endorsing enjoyment motives was associated with participation in organized PA (Odds Ratio, 95% Confidence Interval: 1.54, 1.24-1.91). Competence motives were associated with participation in group-based PA (1.27, 1.11-1.46) and achievement of PA recommendations (1.95, 1.37-2.78). Conclusion: Targeting enjoyment and competence motives may be associated with increased participation in organized and group-based PA as well as with an increased likelihood of meeting PA guidelines in youth

Jean-Baptiste Bélanger, hydraulic engineer, researcher and academic

Jean-Baptiste BÉLANGER (1790-1874) worked as a hydraulic engineer at the beginning of his career. He developed the backwater equation to calculate gradually-varied open channel flow properties for steady flow conditions. Later, as an academic at the leading French engineering schools (Ecole Centrale des Arts et Manufactures, Ecole des Ponts et Chaussées, and Ecole Polytechnique), he developed a new university curriculum in mechanics and several textbooks including a seminal text in hydraulic engineering. His influence on his contemporaries was considerable, and his name is written on the border of one of the four facades of the Eiffel Tower. BÉLANGER's leading role demonstrated the dynamism of practicing engineers at the time, and his contributions paved the way to many significant works in hydraulics

A single hollow beam optical trap for cold atoms

We present an optical trap for atoms that we have developed for precision spectroscopy measurements. Cold atoms are captured in a dark region of space inside a blue-detuned hollow laser beam formed by an axicon. We analyze the light potential in a ray optics picture and experimentally demonstrate trapping of laser-cooled metastable xenon atoms.Comment: 12 pages, 8 figure

La construction sociale de l’individu chez Tarde et Durkheim

La tradition sociologique oppose généralement deux thèses : individualiste et holiste. Ces caractérisations laissent entendre que la première thèse s’attarde à l’action des individus pour expliquer la société. Ce style s’est développé surtout en Allemagne grâce à Max Weber. La thèse holiste prend une position plus globale en expliquant la société par des faits sociaux. Celle-ci est dite française par l’entremise du père de la sociologie, Émile Durkheim. Pourtant, plusieurs auteurs français ont snobé la tradition allemande pour ramener à l’avant-scène un compatriote qui s’est opposé à Durkheim : Gabriel Tarde. Ces réintroductions ont été produites pour s’opposer aux thèses durkheimiennes qui laisseraient l’individu victime du contexte social dans lequel il se trouve. La sociologie allemande propose déjà une opposition de ce type avec les théories postulant un objet réel et particulier à la sociologie. Pourquoi réintroduire un auteur disparu en sociologie pour prendre la place d’autres qui sont encore là? L’hypothèse serait que Tarde propose un individualisme différent qui se traduirait par une notion d’individu particulière. L’étude comparative du corpus durkheimien et tardien révèle pourtant que ces deux auteurs partagent la plupart des caractéristiques associées à la définition du sens commun de l’individu. L’opposition entre Durkheim et Tarde ne relève pas de la place de l’individu dans la science sociale, mais d’une interprétation différente de certains aspects de la théorie statistique. Ces théories sociales ont été construites grâce à cette notion ce qui laisse penser que certains des problèmes explicatifs de ces dernières pourraient être liés à cette base.The sociological tradition generally opposes two theses: individualism and holism. The individualist wants to explain society through the actions of its actors. It has been upheld by the German tradition with Max Weber at its head. On the other hand, the holist thesis tries to explain society from above through social facts. The French sociology is central here with Emile Durkheim as its forefather. Despite this antagonism, some French authors have felt the need to reintroduce a forgotten figure from their past: Gabriel Tarde. German sociology already embodied the individualistic view, why then revitalize an old adversary of Durkheim? The working hypothesis was that Tarde might have some very good and different insight on the definition of what the individual needed to be. The comparative study of Tarde’s and Durkheim’s work demonstrates that it isn’t so. They share the same basic common sense definition of the notion of individual. Their opposition was based on some interpretation of statistical theory for sociology. This conclusion points toward the possibility that this notion is the basis for the theorization of sociology which might be a major source of its explanatory problems

Periodic Modulations in an X-ray Flare from Sagittarius A*

We present the highly significant detection of a quasi-periodic flux modulation with a period of 22.2 min seen in the X-ray data of the Sgr A* flare of 2004 August 31. This flaring event, which lasted a total of about three hours, was detected simultaneously by EPIC on XMM-Newton and the NICMOS near-infrared camera on the HST. Given the inherent difficulty in, and the lack of readily available methods for quantifying the probability of a periodic signal detected over only several cycles in a data set where red noise can be important, we developed a general method for quantifying the likelihood that such a modulation is indeed intrinsic to the source and does not arise from background fluctuations. We here describe this Monte Carlo based method, and discuss the results obtained by its application to a other XMM-Newton data sets. Under the simplest hypothesis that we witnessed a transient event that evolved, peaked and decayed near the marginally stable orbit of the supermassive black hole, this result implies that for a mass of 3.5 x 10^{6} Msun, the central object must have an angular momentum corresponding to a spin parameter of a=0.22.Comment: 4 pages, 6 figures, submitted to ApJ

Static quantities of a neutral bilepton in the 331 model with right-handed neutrinos

A neutral vector boson can possess static electromagnetic properties provided that the associated field is no self-conjugate. This possibility is explored in the $SU_C(3) X SU_L(3) X U_N(1)$ model with right-handed neutrinos, which predicts a complex neutral gauge boson $Y^0$ in a nontrivial representation of the electroweak group. In this model the only nonvanishing form factors are the CP-even ones, which arise from both the quark and gauge sectors, and contribute to the magnetic dipole and the electric quadrupole moments of this neutral particle.Comment: 10 pages, 6 figures, submitted to Phys. Rev.