Effets du taux de perte de poids suite à un programme de perte de poids de 5 semaines sur les changements de la composition corporelle et du profil métabolique chez des femmes post-menopausées, obèses et sédentaires

Obesity, worldwide epidemic, affects one third of all Canadian women over 50. Menopause is a critical period for these women in particular when accompanied by overweight. In fact, hormonal changes and waist enlargement are associated with metabolic deteriorations and multiply risks of heart diseases considerably. Therefore, it seems important to make extra efforts in primary and secondary prevention in order to decrease the negative impacts of obesity in postmenopausal women. Some late studies demonstrate that a loss of 10 to 15% of initial body weight is efficient to improve the metabolic profile of obese individuals. However, postmenopausal women have been under-represented in weight loss studies. This is a surprising fact considering that this particular group (1) has a higher risk of cardiovascular diseases compared to younger women and (2) can also benefit significantly from a weight loss program aimed at improving the overall health profile. Moreover, when dieting without exercising, almost 25% of the weight loss will be of lean body mass, which can contribute to a decrease in resting metabolic rate. General guidelines for the treatment of obesity in the adult population recommend a weight loss of 1 to 2 lbs per week. Except for the fact that there is no extra benefit for health at higher rates of weight loss, there is no other rational explanation related to those recommendations. Moreover, it suggests a combination of caloric restriction and exercise program, the latter not always feasible, particularly with obese elderly with functional limitations. Despite the abundant literature on weight loss, no study has specifically investigated the impact of the rate of weight loss by diet alone on the body composition and the resting metabolic rate, which are major contributing factors of long-term weight loss maintenance. The goal of the project was to study the effects of the rate of weight loss during a hypocaloric diet, without exercise, on changes in body composition (fat mass and lean body mass) and the metabolic profile (resting arterial blood pressure, lipid profile and resting metabolic rate) in sedentary obese postmenopausal women. For this purpose, 20 obese (baseline % body fat: 46.4 « 5.1 %), postmenopausal (no menses for 12 consecutive months) and sedentary women ( or = 0.74 kg/week (or 1.6 lb/week) does not seem to produce extra benefits on the metabolic profile or to be related to a greater loss of fat mass after 5 weeks. In fact, the greater decreases of body weight in the high rate group may be explained in part by a loss of lean body mass. Based on our observations, it seems that current guidelines which recommend an energy deficit leading to weight losses up to 0.91 kg per week (2 lbs per week) may not be optimal for obese postmenopausal women when no exercise is added to the weight loss program. Two alternatives appear from our results: first, a more conservative approach with a maximal rate of weight loss of 0.6 to 0.7 kg per week (or 1.3 to 1.5 lb per week) seems to be optimal to better preserve lean body mass when no exercise is incorporated in the weight loss program. Secondly, in the case of a caloric restriction aiming at a weight loss of more than 0.7 kg/week, the addition of an exercise program should be considered in order to minimize the loss of muscular mass. Other studies are therefore necessary to validate these hypotheses

Rabies-Related Knowledge and Practices Among Persons At Risk of Bat Exposures in Thailand

Rabies is a fatal encephalitis caused by lyssaviruses. Evidence of lyssavirus circulation has recently emerged in Southeast Asian bats. We surveyed persons regularly exposed to bats and bat habitats in Thailand to assess rabies‐related knowledge and practices. Targeted groups included guano miners, bat hunters, game wardens, and residents/personnel at Buddhist temples where mass bat roosting occurs. Of the 106 people interviewed, 11 (10%) identified bats as a source of rabies. History of a bat bite/scratch was reported by 29 (27%), and 38 (36%) expressed either that they would do nothing or that they did not know what they would do in response to a bat bite. Guano miners were less likely than other groups to indicate animal bites as a mechanism of transmission (68% vs. 90%, p=0.03) and were less likely to say they would respond appropriately to a bat bite or scratch (61% vs. 27%, p=0.003). These findings indicate a need for educational outreach in Thailand to raise awareness of bat rabies, promote exposure prevention, and ensure health‐seeking behaviors for bat‐inflicted wounds, particularly among at‐risk groups

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Interventions nutrionnelles pour la prévention et le traitement de l'obésité : investigations d'approches originales qui sortent des sentiers battus

L'accumulation de tissu adipeux est un phénomène complexe caractérisé par de grandes variations étiologiques interindividuelles et des conséquences sérieuses pour la santé. Dans le but ultime de concevoir le traitement ou l'action préventive les plus complets et efficaces qui soient, il importe d'abord de tester la contribution de divers agents impliqués dans le contrôle du poids et de l'appétit. Cette thèse de doctorat documente l'impact de différents types d'interventions nutritionnelles sur des aspects préventifs et curatifs de l'embonpoint et de l'obésité. Les résultats issus d'un premier article scientifique démontrent qu'une restriction énergétique intermittente n'apporte pas de bénéfices supplémentaires sur la composition corporelle et le profil métabolique en comparaison à une restriction énergétique continue. Ils renforcent aussi l'idée qu'une perte de 5% du poids initial constitue un objectif prudent et valable pour l'amélioration de la santé métabolique. Un second projet de recherche a démontré qu'à densité énergétique, apparence et palatabilité égales, l'effet de contexte mais non la composition en nutriments a exercé une influence significative sur le contrôle de l'appétit. Les résultats issus d'une troisième étude suggèrent ensuite qu'une diète de faible densité énergétique à haut potentiel rassasiant puisse avoir un impact bénéfique sur la perte de poids et le contrôle de l'appétit d'individus dont les signaux de satiété sont faibles. Une quatrième étude, portant sur l'offre alimentaire saine et abordable dans une école primaire, a démontré qu'il est possible d'obtenir un compromis acceptable entre palatabilité, satisfaction et apport énergétique spontané chez des enfants de 4 à 12 ans. Enfin, la comparaison d'individus végétaliens et omnivores laisse présumer d'un rôle potentiel de l'alimentation en tant que moyen de prévention de l'accumulation des polluants organiques persistants dans le corps humain. L'ingestion d'olestra n'a toutefois pas eu le succès escompté pour contrer l'hyper-concentration plasmatique de composés organochlorés qui est survenue en réponse à une perte de poids modérée. En conclusion, les résultats des travaux présentés dans cette thèse suggèrent que l'alimentation santé peut avoir un impact favorable sur le contrôle du poids et de l'appétit. Cependant, il y a des limites à en améliorer la fonctionnalité

Promoting respect for the rules and injury prevention in ice hockey : evaluation of the Fair-Play program

Objective: To reduce the number of transgressions to the rule, the occurrence of violent acts and to prevent injuries. Hockey Québec adopted the Fair-Play Program (FPP). The objective of the present study was to evaluate the effectiveness of the FPP. Methods: 52 Bantam (14–15 years) teams participated in this cohort study. In total, 49 games (13 with the FPP, 36 without FPP) were systematically assessed for transgressions to the rule. Body checking was allowed in all games. Transgressions to the rule data were obtained using a real time observation system in a natural setting, while injury data were collected through a self-administered questionnaire. Data were analysed using generalised linear, models with generalised estimating equations accounting for potential team effect. Results: The number of penalties per game was significantly lower (p<0.01) for games played with the FPP. Overall, no difference was noted in the number of transgressions observed during games played with or without the FPP. Players in leagues where the FPP was used held their opponents more frequently (p<0.0001). On the other hand, players in leagues without the FPP showed and hit more (p=0.05). No difference was noted in the injury rate for games played with or without the FPP. Conclusions: This study showed that the FPP is one of the tools available to help those in the hockey world promote fair play values. Moreover, this project clearly showed the importance of program evaluation and the value of direct observation in a natural setting

Behavioural and metabolic characterisation of the low satiety phenotype

Some individuals report weak appetite sensations and thus, have higher susceptibility to overeating. The aim of this study was (1) to evaluate the reliability of the satiety quotient (SQ), a marker of satiety effi- ciency; (2) to characterize the biopsychobehavioural profiles of individual presenting low satiety effi- ciency, i.e. the low satiety phenotype and (3) to document the impact of a weight loss program on these profiles. Sixty-nine obese men (BMI 33.6 ± 3.0 kg/m2, age 41.5 ± 5.7 years) participated in a 16- week, non-restrictive weight loss intervention. Visual analog scales for appetite sensations in response to a test-meal were completed twice at baseline. Blood samples were collected before and during one test-meal. Questionnaires were administered before and after the intervention. The mean SQ showed good reliability (ICC = 0.67). Baseline SQ scores tended to be negatively correlated with external hunger, anxiety and night eating symptoms (p < 0.10). Moreover, the low satiety phenotype showed a lower cortisol response to the test-meal (p < 0.05). The SQ seems to be a reliable marker of weaker appetite sensation responses. Stress/anxiety could be involved in the low satiety phenotype but did not influence the biopsychobehavioural changes in response to the intervention

Searches for the ZγZ\gamma decay mode of the Higgs boson and for new high-mass resonances in pppp collisions at s=13\sqrt{s} = 13 TeV with the ATLAS detector

International audienceThis article presents searches for the Zγ decay of the Higgs boson and for narrow high-mass resonances decaying to Zγ, exploiting Z boson decays to pairs of electrons or muons. The data analysis uses 36.1 fb$^{−1}$ of pp collisions at $\sqrt{s}=13$ recorded by the ATLAS detector at the CERN Large Hadron Collider. The data are found to be consistent with the expected Standard Model background. The observed (expected — assuming Standard Model pp → H → Zγ production and decay) upper limit on the production cross section times the branching ratio for pp → H → Zγ is 6.6. (5.2) times the Standard Model prediction at the 95% confidence level for a Higgs boson mass of 125.09 GeV. In addition, upper limits are set on the production cross section times the branching ratio as a function of the mass of a narrow resonance between 250 GeV and 2.4 TeV, assuming spin-0 resonances produced via gluon-gluon fusion, and spin-2 resonances produced via gluon-gluon or quark-antiquark initial states. For high-mass spin-0 resonances, the observed (expected) limits vary between 88 fb (61 fb) and 2.8 fb (2.7 fb) for the mass range from 250 GeV to 2.4 TeV at the 95% confidence level