Stellar Populations in Barred Galaxies

We developed an iterative technique to better characterize stellar populations and the central activity of barred galaxies using evolutionary synthesis codes and OASIS data. The case of NGC5430 is presented here. Our results are reinforcing the role played by the bar and nuclear structures for the evolution of galaxies.Comment: 2 pages, 1 figure, to be published in the proceedings of IAU Symp. 262 "Stellar Populations - Planing for the Next Decate" (Aug. 2009

On the Mediational Role of Feelings of Self-Determination in the Workplace: Further Evidence and Generalization

Les objectifs de cette étude visaient à vérifier la généralisation des résultats de Deci et al. (1989) et à évaluer la validité d'un modèle préliminaire de qualité de vie au travail dans lequel les sentiments d'autodétermination jouent un rôle important en tant que médiateurs. Ce modèle stipule que les environnements de travail informationnel et contrôlant auront des impacts opposés sur les sentiments d'autodétermination. Ces sentiments devraient par la suite influencer directement des comportements organisationnels et des variables de santé de l'employé. 184 employés canadiens francophones provenant de différentes organisations ont répondu à l'une des deux versions d'un questionnaire assigné aléatoirement. Les deux échantillons servaient à évaluer le modèle en utilisant deux perspectives d'environnement de travail : informationnel et contrôlant. Dans l'échantillon 1, les employés évaluaient le style du supérieur immédiat alors que dans l'échantillon 2, les sujets évaluaient le climat global de travail. Les résultats d'analyses corrélationnelles et des pistes causales ont confirmé les liens postulés entre les perceptions d'environnement de travail informationnel/contrôlant, les sentiments d'autodétermination et la qualité de vie au travail. Les sentiments d'autodétermination ainsi que la satisfaction et l'intérêt au travail jouaient un rôle de médiateur afin de prédire des impacts proximaux (perceptions d'absentéisme volontaire, distraction au travail et intentions de quitter son travail) de même que des impacts plus distaux ( perception de problèmes de santé physique et mental, consommation de tabac et d'alcool). Ces résultats étaient confirmés dans les deux échantillons.The goals of this study were to extend and to verify the generalizability of Deci et al.'s (1989) results, and to test the validity of a preliminary quality of worklife model in which feelings of self-determination play a key mediational role. This model states that informational and controlling work environments will impact in opposite ways on feelings of self-determination. These feelings should then trigger positive impacts on global work satisfaction and work interest. These two latter variables, in turn, are postulated to impact directly on organizational behaviors and general health variables. Subjects were 184 full-time French Canadian employees from different work settings. They were randomly assigned to one of two versions of a questionnaire assessing the different constructs of the model. Two samples were created to cross-validate results and to test the model with two different loci of perceived informational and controlling work environments. In sample 1, subjects assessed their perceptions of their immediate supervisor's styles whereas in sample 2, subjects assessed their perceptions of the global work climate. Results from correlational and path analyses confirmed the predicted relationships between perceptions of informational/controlling environments, feelings of self-determination and the quality of worklife. The expected mediational role of feelings of self-determination as well as of work satisfaction and interest in explaining proximal impacts (i.e., self-perceptions of voluntary absenteeism, distraction at work, and intentions to change job) as well as more distal impacts (i.e., self-perceptions of mental and physical health, cigarette, and alcohol use) was confirmed across samples

Self-organized criticality in the intermediate phase of rigidity percolation

Experimental results for covalent glasses have highlighted the existence of a new self-organized phase due to the tendency of glass networks to minimize internal stress. Recently, we have shown that an equilibrated self-organized two-dimensional lattice-based model also possesses an intermediate phase in which a percolating rigid cluster exists with a probability between zero and one, depending on the average coordination of the network. In this paper, we study the properties of this intermediate phase in more detail. We find that microscopic perturbations, such as the addition or removal of a single bond, can affect the rigidity of macroscopic regions of the network, in particular, creating or destroying percolation. This, together with a power-law distribution of rigid cluster sizes, suggests that the system is maintained in a critical state on the rigid/floppy boundary throughout the intermediate phase, a behavior similar to self-organized criticality, but, remarkably, in a thermodynamically equilibrated state. The distinction between percolating and non-percolating networks appears physically meaningless, even though the percolating cluster, when it exists, takes up a finite fraction of the network. We point out both similarities and differences between the intermediate phase and the critical point of ordinary percolation models without self-organization. Our results are consistent with an interpretation of recent experiments on the pressure dependence of Raman frequencies in chalcogenide glasses in terms of network homogeneity.Comment: 20 pages, 18 figure

Self-organization with equilibration: a model for the intermediate phase in rigidity percolation

Recent experimental results for covalent glasses suggest the existence of an intermediate phase attributed to the self-organization of the glass network resulting from the tendency to minimize its internal stress. However, the exact nature of this experimentally measured phase remains unclear. We modify a previously proposed model of self-organization by generating a uniform sampling of stress-free networks. In our model, studied on a diluted triangular lattice, an unusual intermediate phase appears, in which both rigid and floppy networks have a chance to occur, a result also observed in a related model on a Bethe lattice by Barre et al. [Phys. Rev. Lett. 94, 208701 (2005)]. Our results for the bond-configurational entropy of self-organized networks, which turns out to be only about 2% lower than that of random networks, suggest that a self-organized intermediate phase could be common in systems near the rigidity percolation threshold.Comment: 9 pages, 6 figure

Comorbidity Between Major Depression and Alcohol Use Disorder From Adolescence to Adulthood

Background—Limited information exists regarding the long-term development of comorbidity between Major Depressive Disorder (MDD) and Alcohol Use Disorder (AUD; abuse/dependence). Using a representative prospective study, we examine multiple aspects pertaining to MDD+AUD comorbidity, with a focus on the relation between disorders across periods (adolescence, early adulthood, adulthood) and cumulative impairments by age 30. Method—816 participants were diagnostically interviewed at ages 16, 17, 24, and 30. Results—Rates of comorbid MDD+AUD were low in adolescence (2%), but increased in early adulthood (10%) and adulthood (7%). Rates of cumulative comorbidity were elevated (21%). Most individuals with a history of MDD or AUD had the other disorder, except for women with MDD. Prospectively, adolescent AUD predicted early adult MDD, while early adult MDD predicted adult AUD. Compared to pure disorders, MDD+AUD was associated with higher risk of alcohol dependence, suicide attempt, lower global functioning, and life dissatisfaction. Conclusions—Lifetime rates of comorbid MDD+AUD were considerably higher than in crosssectional studies. Comorbidity was partly explained by bidirectional and developmentally-specific associations and predicted selected rather than generalized impairments. Clinically, our findings emphasize the need to always carefully assess comorbidity in patients with MDD or AUD, taking into account concurrency and developmental timing

Adolescent suicide attempts and adult adjustment

Background: Adolescent suicide attempts are disproportionally prevalent and frequently of low severity, raising questions regarding their long-term prognostic implications. In this study, we examined whether adolescent attempts were asso- ciated with impairments related to suicidality, psychopathology, and psychosocial functioning in adulthood (objective 1) and whether these impairments were better accounted for by concurrent adolescent confounders (objective 2). Method: Eight hundred and sixteen adolescents were assessed using interviews and question- naires at four time points from adolescence to adulthood. We examined whether lifetime suicide attempts in adolescence (by T2, mean age 17) predicted adult out- comes (by T4, mean age 30) using linear and logistic regressions in unadjusted models (objective 1) and adjusting for sociodemographic background, adolescent psychopathology, and family risk factors (objective 2). Results: In unadjusted analyses, adolescent suicide attempts predicted poorer adjustment on all outcomes, except those related to social role status. After adjustment, adolescent attempts remained predictive of axis I and II psychopathology (anxiety disorder, antisocial and borderline personality disorder symptoms), global and social adjustment, risky sex, and psychiatric treatment utilization. However, adolescent attempts no longer predicted most adult outcomes, notably suicide attempts and major depressive disorder. Secondary analyses indicated that associations did not differ by sex and attempt characteristics (intent, lethality, recurrence). Conclusions: Adolescent suicide attempters are at high risk of protracted and wide-ranging im- pairments, regardless of the characteristics of their attempt. Although attempts specifically predict (and possibly influence) several outcomes, results suggest that most impairments reflect the confounding contributions of other individual and family problems or vulnerabilites in adolescent attempters

Decision-Making Measured by the Iowa Gambling Task in Patients with Alcohol Use Disorders Choosing Harm Reduction versus Relapse Prevention Program

AIMS: Two main therapeutic programs were offered to patients suffering from alcohol use disorders (AUDs): avoid the alcohol by abstinence or controlling their consumption. After information and motivational sessions, the patient chooses his own therapeutic plan. However, patients with AUD exhibit poor decision-making. The purpose of this study was to investigate the decision-making in AUD by comparing patients who chose to reduce and control their consumption to those who chose abstinence program. METHODS: Sixty-seven subjects with alcohol use disorder were included (AUD group) for treatment, choosing either a relapse prevention program (RPP) or a harm reduction program (HRP). Patients were compared to a healthy control group (n = 31). Cognitive skills were assessed through the Montreal Cognitive Assessment test, the National Adult Reading Test, the Trail Making Test and the Iowa Gambling Task (IGT). RESULTS: Thirty-seven patients with AUD chose the RPP while 30 followed a HRP. The AUD group performed worse than controls on the IGT. The RPP group had significantly lower performance than both HRP and control groups (these later groups being not statistically different). No correlation was observed between the available clinical, cognitive and intellectual measures. CONCLUSION: This study confirms that the decision-making process of patients with an alcohol use disorder is impaired. However, the 2 groups differ on the IGT scores, despite comparable clinical and cognitive profiles. The patients\u27 decision-making abilities could be a useful guide when developing therapeutic programs

Des indicateurs en santé travail - Les troubles musculo-squelettiques du membre supérieur en France

France has sought to develop a series of indicators intended to monitor health trends at the national level. Since its creation in 1998, the Department of Occupational Health (DST) of the French Institute of Public Health Surveillance (InVS) has worked to develop monitoring programs, with the goal of producing such data regularly and thus improving our knowledge of occupational health risks. The data sources have expanded over time. In 2009, the DST established a program for the regular production of indicators intended to report the national workplace health situation and its trends over time. These indicators come from various sources and will be published regularly on the InVS website: www.invs.sante.fr. This third report covers musculoskeletal diseases of the upper limbs. This document summarizes data about their frequency in terms of prevalence and incidence, as well as about the frequency of exposures to the principal known risk factors, according to sex, age, occupational categories, and broad activity sectors. It also provides information about the proportion of these musculoskeletal diseases that are attributable to work, according to occupational categories and broad activity sectors, and about the scale of their under-reporting generally and as compensable occupational diseases. Finally, some questions enable us to put the results presented into perspective

Mitochondrial activities in human cultured skin fibroblasts contaminated by Mycoplasma hyorhinis

BACKGROUND: Mycoplasma contaminations are a recurrent problem in the use of cultured cells, including human cells, especially as it has been shown to impede cell cycle, triggering cell death under various conditions. More specific consequences on cell metabolism are poorly known. RESULTS: Here we report the lack of significant consequence of a heavy contamination by the frequently encountered mycoplasma strain, M. hyorhinis, on the determination of respiratory chain activities, but the potential interference when assaying citrate synthase. Contamination by M. hyorhinis was detected by fluorescent imaging and further quantified by the determination of the mycoplasma-specific phosphate acetyltransferase activity. Noticeably, this latter activity was not found equally distributed in various mycoplasma types, being exceptionally high in M. hyorhinis. CONCLUSION: While we observed a trend for respiration reduction in heavily contaminated cells, no significant and specific targeting of any respiratory chain components could be identified. This suggested a potential interference with cell metabolism rather than direct interaction with respiratory chain components