La gestion des contre-arguments dans le texte argumentatif ecrit chez les elèves de 8 à 12 ans et les adultes compétents

The objective of this research is to determine to what extend children from 8 to 12–13 years old become able to compose coherent counter-argumentative texts. 116 children and 26 quasi expert adults were asked to write a text beginning and ending with 2 imposed counterargumentative sentences. In that specific metalinguistic situation, pupils from 8 to 10 hesitate what text type (whether argumentative or not) to produce. When 10–11 years old, they seem aware the situation needs an argumentative response, but that does not necessary enable them to counter-argue. By children from 11–12 years old and adults, texts are most frequently counter-argumentative. It is proposed to explain this evolution by a progressive mastery of a possible argumentative prototypical text schema which could enable pupils to understand the 2 imposed sentences as knots to be expanded from a complexe argumentative text, and, in the same way, to compose this text. This explanative hypothesis is apparently sustained by the positive effects on the performances of 40 pupils from 8 to 12–13 years old of didactic interventions intended to make them sensible to argumentative text properties.     

Determining propulsive force in front crawl swimming: a comparison of two methods

To evaluate the propulsive forces in front crawl arm swimming, derived from a three-dimensional kinematic analysis, these values were compared with mean drag forces. The propulsive forces during front crawl swimming using the arms only were calculated using three-dimensional kinematic analysis combined with lift and drag coefficients obtained in fluid laboratories. Since, for any constant swimming speed, the mean propulsive force should be equal to the mean drag force acting on the body of the swimmer, mean values of the calculated propulsive forces were compared with the mean drag forces obtained from measurements on a Measuring Active Drag (MAD) system. The two methods yielded comparable results, the mean difference between them being only 5% (2 N). We conclude that propulsive forces obtained from three-dimensional kinematic analysis provide realistic values. The calculation of the propulsive force appears to be rather sensitive to the point on the hand at which the velocity is estimated and less sensitive to the orientation of the hand.     

A remaking pedagogy: adaptation and archetypes in the child’s multimodal reading and writing

This paper proposes combining theories about, and practices of, using archetypes and adaptation in education for the purposes of multimodal literacy learning. Within such contexts, children of primary school age act as readers, performers and researchers, exploring and analysing existing adaptations of archetypal stories and images across time, space and platforms, as well as writers constructing and producing their own adaptations of archetypes in varying forms. Our suggestions are that ‘revisiting’ and ‘remaking’ existing texts and practices in the multimodal primary classroom can be a route to a deeper and more sophisticated learning experience, and one which challenges current definitions of reading, writing and literacy.     

History and Singularity of Krav-Maga

Abstract

Krav-Maga (‘contact combat’) is an Israeli combat discipline practiced by thousands of individuals worldwide. During the past few decades, it has attracted a considerable amount of attention mainly as a self-defence system, although its origins are also rooted in sport. Despite the widespread popularity of Krav-Maga, its origins, history, and evolution have not been seriously examined in the academic literature, nor has its key role in promoting the use of reflex reactions in combat. This paper addresses these gaps in the literature while emphasizing the distinctive characteristics of Israeli combat disciplines. It also challenges popular misconceptions about the historical roots of Krav-Maga. Our research leads to three key conclusions: First, Israeli combat disciplines played a pioneering role in the use of situational awareness and reflex responses to an attack – in preference to a reliance on forms training. Second, contrary to commonly held beliefs, Krav-Maga is a direct development of Jewish hand-to-hand combat disciplines that can be traced back to 1891. Third, the development of Krav-Maga may be viewed as a reflection of historical and political events affecting the Jewish people from the late nineteenth century.     

Accumulating 10,000 steps: does this meet current physical activity guidelines?

The purpose of this study was to determine whether taking 10,000 steps in a day is equivalent to meeting the current minimum physical activity guidelines of accumulating at least 30 min of moderate physical activity (IMPA). Fifty-nine women ages 20-65 years wore a pedometer and accelerometer concurrently on their right hip for 1 day. There were no differences in the age, body mass index, or the amount of time the pedometers and accelerometers were worn between the 10K+ and the < 10K groups. The 10K+ group accumulated significantly more steps and minutes of MPA than the < 10K group (M = 13,084 steps, SD = 2,603 vs. M = 7,518 steps, SD = 1,956; and M = 62.1 min, SD = 27.7 vs. M = 38.8 min, SD = 18.9; p < .05). A 2 x 2 chi-square analysis demonstrated no difference between the proportions of 10K and < 10K participants who met the step goal, when all minutes of MPA accumulated throughout the day were considered (chi2 = 1.8, df = 1, p = .175). When only continuous bouts of MPA lasting > 5 min and > 10 min were considered, a significantly greater proportion of 10K participants met the current physical activity guidelines than the < 10K participants (chi2 = 11.5, df = 1, p = .001, and chi2 = 5.9, df = 1, p = .015, respectively). Our finding, suggest that individuals who accumulate 10,000 steps/day are more likely to meet the current physical activity guidelines by engaging in the length of bouts promoted by the Centers for Disease Control and Prevention and the American College of Sports Medicine (Pate et al., 1995) and the US Surgeon General (U.S. Department of Health and Human Services, 1996). However, the data also reveal that accumulating 10,000 steps/day does not guarantee meeting the guidelines in the bout lengths documented to confer the health benefits of physical activity.     

Effect of postural changes on 3D joint angular velocity during starting block phase

Abstract

Few studies have focused on the effect of posture during sprint start. The aim of this study was to measure the effect of the modification of horizontal distance between the blocks during sprint start on three dimensional (3D) joint angular velocity. Nine trained sprinters started using three different starting positions (bunched, medium and elongated). They were equipped with 63 passive reflective markers, and an opto-electronic Motion Analysis® system was used to collect the 3D marker trajectories. During the pushing phase on the blocks, norm of the joint angular velocity (NJAV), 3D Euler angular velocity (EAV) and pushing time on the blocks were calculated. The results demonstrated that the decrease of the block spacing induces an opposite effect on the angular velocity of joints of the lower and the upper limbs. The NJAV of the upper limbs is greater in the bunched start, whereas the NJAV of the lower limbs is smaller. The modifications of NJAV were due to a combination of the movement of the joints in the different degrees of freedom. The medium start seems to be the best compromise because it leads, in a short pushing time, to a combination of optimal joint velocities for upper and lower segments.