Effets du sport sur le comportement social de l'adolescent

Sans résumé     

Brain opiates

Morphine, which is obtained from poppies, has pharmacological properties which make it both a powerful pain-relieving drug and a narcotic feared for the dependency which it induces in those who use it. Study of the mode of action of morphine has revealed related endogenous substances in the brain. These brain opiates have remarkable properties, which researchers are just beginning to discover.     

Computing and the Teaching of Structural Analysis/ Le calcul par ordinateur et l'enseignement de l'analyse des structures

Computer structural analysis is now one of the fundamental pillars in the teaching of engineering. The task is to capitalize on all the new technologies in order primarily to help the students understand the behaviour of structures and, by the same token, improve their ability to analyze them. Consequently, the computer has to be exploited in a smart and ingenious way to achieve this task better. If, in the past, this was done in a more or less successful way, it is nowadays extremely difficult, if not quite impossible, to perform this task in a satisfactory manner. This is changing not only the teaching of structural analysis but also the content of the engineering courses. Hence, a reassessment and a reorganization of the teaching of computing for structural analysis have to take place. In this paper, a few ideas on the teaching of computing for structural analysis are discussed.     

Worldwide variation in the performance of children and adolescents: An analysis of 109 studies of the 20-m shuttle run test in 37 countries

Abstract

This study is a meta-analysis of 109 reports of the performance of children and adolescents on the 20-m shuttle run test (20-mSRT). The studies were performed in 37 countries and included data on 418,026 children, tested between 1981 and 2003. Results were expressed as running speed (km · h^?1) at the final completed stage of the 20-mSRT. Raw data were combined with pseudodata using Monte Carlo simulation. The 20-mSRT performances were expressed as z-scores relative to all children of the same age and sex from all countries. An overall “performance index” was derived for each country as the average of the age- and sex-specific z-scores for all children from that country. Factorial analysis of variance was used to compare scores among countries and regions, and between boys and girls of the same age. There was wide and significant (P < 0.0001) global variability in the performance of children. The best performing children were from the Northern European countries Estonia, Iceland, Lithuania, and Finland (0.6 – 0.9 standard deviations above the global average). The worst performing children were from Singapore, Brazil, USA, Italy, Portugal, and Greece (0.4 – 0.9 standard deviations below the global average). There is evidence that performance was negatively related to being overweight, as well as to a country's average temperature.     

The Effect of Schools and Classes on Noncognitive Outcomes

This article reports on the effects of individual background characteristics, classes, and schools on 4 noncognitive outcomes at the end of the 1st cycle secondary education in Flanders. The outcomes are: the degree to which the student feels at home in the school environment, the extent to which the student does his/her best for the school work, the academic self-concept, and the social integration in the class. Firstly, the raw class and school effects are estimated. Secondly, a broad set of background variables is introduced to isolate the net class and school effects. Thirdly, class and school composition variables are introduced. Finally, the additional predictive power of a number of other student, class, and school characteristics is documented.     

Discriminant analysis of anthropometric and biomotor variables among elite adolescent female athletes in four sports

The aim of this study was to identify anthropometric and biomotor variables that discriminated among groups of elite adolescent female athletes aged 14.3 +/- 1.3 years (mean +/- s) from four different sports (tennis, n = 15; swimming, n = 23; figure skating, n = 46; volleyball, n = 16). The anthropometric variables included body mass, height, bi-epicondylar breadth of the distal extremity of the humerus and femur, maximal girth of the calf and biceps and the sum of five adipose skinfolds. The biomotor variables were maximal aerobic power, muscular endurance and flexibility of the trunk. Discriminant analysis revealed three significant functions (P < 0. 05). The first discriminant function primarily represented differences between figure skaters and all other groups of athletes. The other two underlined anthropometric and biomotor differences between swimmers and volleyball players and between tennis players and swimmers, respectively. After validation, the analysis showed that 88% of the athletes were correctly classified in their respective sports. Our model confirms that elite adolescent female athletes show physical and biomotor differences that clearly distinguish them according to their particular sport.