Correlates of extracurricular sport participation among Swiss adolescents

Background: Based on a large national survey on the health of adolescents, this paper focuses on the socio-demographic and lifestyle correlates of sport practice among Swiss adolescents. The SMASH2002 database includes 7428 vocational apprentices and high school students between the ages of 16 and 20 who answered a self-administered anonymous questionnaire containing 565 items targeting perceived health, health attitudes and behaviour. Weekly episodes of extracurricular sport activity were measured by a four-category scale, and the sample was dichotomised between active (≥two episodes of sport/week) and inactive (<two episodes of sport/week) respondents. Thirty percent of female respondents and 40.2% of male respondents reported engaging in sport activity at least two to three times a week; another 9.7% of the female and 19.4% of the male respondents reported participating in least one sport activity each day (p<0.01). The percentage of active respondents was higher among students than among vocational apprentices (p<.01), and the rates of sport activity decreased more sharply over time among the apprentices than among the students (p<0.01). Most active adolescents reported having a better feeling of well-being than their inactive peers [among male students: odds ratio (OR): 3.13; 95% confidence interval (95%CI): 1.28-7.70]. The percentage of active females who reported being on a diet was high, and female apprentices exhibited higher involvement in dieting than their inactive peers (OR: 1.68; 95%CI: 1.32-2.14). Relative to the inactive male respondents, the proportion of active male respondents smoking was lower; however, a lower proportion of the latter group did not report drunkenness, and the percentage of those who reported lifetime cannabis consumption was higher among active than inactive students (females, OR:1.57; 95%CI:1.09-2.25; males, OR:1.80; 95%CI: 20-2.69). Conclusion: Organised sport activities should be better tailored to the work schedules of apprentices. Practitioners should be aware of the potential for problematic behaviour in the area of dieting and substance use among a subset of sport-oriented adolescent

Le scellement de sillon est-il efficace dans la prévention de la carie des dents permanentes? : revue cochrane pour le praticien

Scénario: Un enfant de 8 ans, que vous connaissez depuis plusieurs années, se présente à votre consultation pour un contrôle de santé. Il a eu une carie en denture temporaire, qui a été soignée; depuis lors, l'enfant maintient une bonne hygiène buccale et alimentaire. Les parents vous demandent s'il serait indiqué d'appliquer un scellement de sillon pour éviter le développement de nouvelles caries chez leur enfant. Question: Le scellement de sillon (sealant) prévient-il la survenue de caries en denture permanente? Si oui, quel produit utiliser? Contexte: Depuis leur introduction dans les années 60, les programmes de fluoration ont permis un déclin considérable de l'incidence de la carie. Les scellements de sillon semblent également jouer un rôle protecteur en limitant la croissance bactérienne dans les puits et fissures des dents postérieures, zones les plus vulnérables au développement de la maladie carieuse. Néanmoins, il existe un doute sur leur efficacité en cas de risque carieux faible. D'autre part, la diversité des produits (verres ionomères, résine composite, compomères hybrides) proposés sur le marché laisse le praticien dans l'embarras du choix

Reluplex: An Efficient SMT Solver for Verifying Deep Neural Networks

Deep neural networks have emerged as a widely used and effective means for tackling complex, real-world problems. However, a major obstacle in applying them to safety-critical systems is the great difficulty in providing formal guarantees about their behavior. We present a novel, scalable, and efficient technique for verifying properties of deep neural networks (or providing counter-examples). The technique is based on the simplex method, extended to handle the non-convex Rectified Linear Unit (ReLU) activation function, which is a crucial ingredient in many modern neural networks. The verification procedure tackles neural networks as a whole, without making any simplifying assumptions. We evaluated our technique on a prototype deep neural network implementation of the next-generation airborne collision avoidance system for unmanned aircraft (ACAS Xu). Results show that our technique can successfully prove properties of networks that are an order of magnitude larger than the largest networks verified using existing methods.Comment: This is the extended version of a paper with the same title that appeared at CAV 201

Croissance de matériaux moléculaires monocristallins par électrocristallisation

L\u27électrocristallisation est devenue à ce jour une technique incontournable pour la préparation de cristaux moléculaires d\u27espèces radicalaires, obtenus sur l\u27électrode par oxydation ou réduction électrochimique de précurseurs moléculaires. C’est un outil à fort potentiel car il n\u27est pas limité à la seule préparation de cristaux conducteurs mais peut être mis en œuvre facilement pour différents types de cristaux isolants de molécules électro-actives [1]. Une collaboration active entre les laboratoires de Rennes et Angers s’est développée autour de cette technique d’élaboration de monocristaux qui ont l’avantage d’être très purs. Les études physiques sont actuellement menées au niveau international entre différents partenaires, notamment dans le cadre de l’ANR blanche intitulée « ¾-Filled » coordonnée par le Laboratoire de Physique des Solides d’Orsay. Cette activité commune a été soutenue par le réseau CRISTECH avec un financement de 4000 € qui a permis l’achat de deux générateurs de micro-courant pour renouveler et étoffer le parc à Angers ainsi qu’une enceinte thermostatée à Rennes pour équiper le service installé plus récemment. L’affiche présente le principe sur lequel repose cette technique particulière de cristallogénèse, les molécules type qui peuvent être engagées, le matériel nécessaire ainsi que les paramètres qui influent sur la croissance. Deux exemples d’études récentes qui ont pu voir le jour grâce à cette technique sont également mis en exergue. L’une sur le système δ-(EDT-TTF-CONMe2)2X avec X = AsF6– ou Br–, un isolant de Mott à bande ¾ remplie [2] et [3]. L’autre concerne des sels d\u27un autre tétrathiafulvalène dissymétrique, à savoir o-DMTTF qui cristallise dans une structure quadratique très originale avec des anions halogénures comme Cl–, Br– et I– [4]. En particulier, nous avons pu accéder à deux séries de solutions solides [(o-DMTTF)2(X)x(Y)1–x] avec X, Y = Cl–/Br– ou Br–/I–, dans lesquelles des phénomènes d\u27insertion préférentielle de Br– ont été mis en évidence [1] P. Batail et al., Chem. Mater., 10, 3005 (1998). [2] L. Zorina et al., J. of Mater. Chem., 19, 6980 (2009) [3] P. Auban-Senzier et al., Phys. Rev. Lett., 102, 257001 (2009) [4] M. Fourmigué et al., Dalton Trans, 4652 (2008

Resurgence of HIV infection among men who have sex with men in Switzerland : mathematical modelling study

New HIV infections in men who have sex with men (MSM) have increased in Switzerland since 2000 despite combination antiretroviral therapy (cART). The objectives of this mathematical modelling study were: to describe the dynamics of the HIV epidemic in MSM in Switzerland using national data; to explore the effects of hypothetical prevention scenarios; and to conduct a multivariate sensitivity analysis. METHODOLOGY/PRINCIPAL FINDINGS: The model describes HIV transmission, progression and the effects of cART using differential equations. The model was fitted to Swiss HIV and AIDS surveillance data and twelve unknown parameters were estimated. Predicted numbers of diagnosed HIV infections and AIDS cases fitted the observed data well. By the end of 2010, an estimated 13.5% (95% CI 12.5, 14.6%) of all HIV-infected MSM were undiagnosed and accounted for 81.8% (95% CI 81.1, 82.4%) of new HIV infections. The transmission rate was at its lowest from 1995-1999, with a nadir of 46 incident HIV infections in 1999, but increased from 2000. The estimated number of new infections continued to increase to more than 250 in 2010, although the reproduction number was still below the epidemic threshold. Prevention scenarios included temporary reductions in risk behaviour, annual test and treat, and reduction in risk behaviour to levels observed earlier in the epidemic. These led to predicted reductions in new infections from 2 to 26% by 2020. Parameters related to disease progression and relative infectiousness at different HIV stages had the greatest influence on estimates of the net transmission rate. CONCLUSIONS/SIGNIFICANCE: The model outputs suggest that the increase in HIV transmission amongst MSM in Switzerland is the result of continuing risky sexual behaviour, particularly by those unaware of their infection status. Long term reductions in the incidence of HIV infection in MSM in Switzerland will require increased and sustained uptake of effective interventions

A Better Definition of the Kilogram

This article reviews several recent proposed redefinitions of the kilogram, and compares them with respect to practical realizations, uncertainties (estimated standard deviations), and educational aspects.Comment: 10 pages, no figure

Apport des tests de quantification de la libération d’interféron gamma par les lymphocytes T sensibilisés pour le diagnostic des infections tuberculeuses

RésuméL’intradermoréaction cutanée à la tuberculine, couramment utilisée depuis un siècle pour le diagnostic d’infection tuberculeuse, présente de nombreux inconvénients. De nouveaux tests diagnostiques ont été récemment introduits. Ils mesurent soit la production d’interféron-γ dans le sang total, soit le nombre de lymphocytes T producteurs d’interféron-γ après stimulation in vitro par des protéines spécifiques de M. tuberculosis, absentes du BCG et de la plupart des mycobactéries atypiques. Le gain en spécificité permet de réduire les résultats faux positifs chez les sujets vaccinés, évitant ainsi le coût de chimioprophylaxies inutiles et potentiellement toxiques. Le gain en sensibilité, identifiant les infections tuberculeuses latentes parmi les sujets ayant une IDR faussement négative, permet d’accroître les performances diagnostiques dans les populations les plus à risques de progresser vers la tuberculose maladie, à savoir les patients immunodéprimés. L’évaluation de ces tests doit désormais se focaliser sur certains points qui restent à préciser : leur sensibilité chez l’enfant et le sujet immunodéprimé, leurs valeurs prédictives positive et négative et l’interprétation de leur variation éventuelle au cours du temps, que les patients soient traités ou non

Quasi-static and propagating modes in three-dimensional THz circuits

We provide an analysis of the electromagnetic modes of three-dimensional metamaterial resonators in the THz frequency range. The fundamental resonance of the structures is fully described by an analytical circuit model, which not only reproduces the resonant frequencies but also the coupling of the metamaterial with an incident THz radiation. We also demonstrate the contribution of the propagation effects, and show how they can be reduced by design. In the optimized design, the electric field energy is lumped into ultra-subwavelength (λ/100) capacitors, where we insert a semiconductor absorber based on the collective electronic excitation in a two dimensional electron gas. The optimized electric field confinement is exhibited by the observation of the ultra-strong light-matter coupling regime, and opens many possible applications for these structures in detectors, modulators and sources of THz radiation

The scavenger receptors SRA-1 and SREC-I cooperate with TLR2 in the recognition of the hepatitis C virus non-structural protein 3 by dendritic cells

Backgrounds &amp; AimsThe hepatitis C virus NS3 protein is taken up by myeloid cells in a TLR2-independent manner and activates myeloid cells via TLR2. This study aimed to identify the endocytic receptor(s) involved in the uptake of NS3 by myeloid cells and its relation with TLR2. Methods Inhibitors and transfected cells were used to identify the nature of the NS3-binding receptors expressed by myeloid cells. The cooperation between scavenger receptors (SRs) and TLR2 in the NS3-mediated activation of myeloid cells was evaluated using inhibitors, cells from TLR2−/− mice, and confocal microscopy. The involvement of SRs in NS3 cross-presentation was evaluated in vitro using an NS3-specific human T-cell clone. Results We observed that SRs are the main binding structures for NS3 on myeloid cells and identified the SRs SRA-1 and SREC-I as endocytic receptors for NS3. Moreover, both SRs and TLR2 cooperate in NS3-induced myeloid cell activation. Conclusion This study highlights a central role for SRs in NS3 uptake and cross-presentation, and demonstrates a tightly orchestrated cooperation between signalling and endocytic innate receptors in NS3 recognition

A Staggered Decameric Assembly of Human C-Reactive Protein Stabilized by Zinc Ions Revealed by X-ray Crystallography

Human C-reactive protein (CRP) is an acute phase protein, which harbours both host defence and scavenging properties. In this study, we obtained two new crystal forms of CRP, where CRP forms a symmetric, staggered dimer of pentamers. In one of these structures, obtained in the presence of HIV-1 Tat protein, this dimer of pentamers is stabilized by two zinc ions trapped within a cleft of the effector face of CRP. These two decameric interfaces involve complementary surfaces of CRP pentamers and bury a large area of ~2000 Å2 per pentamer, suggesting a biological role of this interface. These two novel decameric interfaces and the involvement of zinc might have important consequences in the understanding of CRP biological functions