Les pièges de l'enseignement des mathématiques

Sans résumé     

The second year of life as a developmental turning point: Implications for «sensitive» caretaking

In the context of the transactional view on development, important changes in the second year of life are highlighted which demand parental adaptations in caregiving practice. The discontinuous growth of enriched cognitive functions in the toddler, as exemplified by Piagetian theory on development of intentionality and symbolic thinking and by recent findings about the emergence of self-awareness and mastery-motivation, meshes with changes in caregiving dimensions. The caregiver, seen as a catalyst for the development of cognitive and social competence must adjust himself to the developmental tasks the infant is coping with. The concept of sensitivity is examined in terms of two important aspects: the social and the didactic. From a Vygotskian standpoint, didactic strategies are very important for cognitive competence. Parents have to facilitate self-initiated learning and to adjust to the infant’s increasing cognitive functions. The influence of a didactic «matching» on overall parent-infant interaction quality, and especially on the quality of attachment, is stressed.     

Effect of a Brazilian Jiu-jitsu-simulated tournament on strength parameters and perceptual responses

This study aimed to analyse the effects of a simulated Brazilian jiu-jitsu (BJJ) tournament on vertical jump performance, grip strength test and perceived effort responses. 22 male BJJ athletes participated in a simulated tournament consisting of three 7 min matches separated by 14 min of rest. Kimono grip strength test (KGST), counter movement jump (CMJ) and rate of perceived exertion (RPE) were measured before and after each match, while RPE of specific areas was assessed after three matches. ANOVA for repeated measures was used to compare strength parameters after each match with the level of significance set at 5%. The key results showed a significant decrease of jump height (p = 0.001) and net vertical impulse in the CMJ (p = 0.031), as well as a reduction of the number of reps in the KGST (p < 0.001). A significant increase of RPE was found throughout the matches (p < 0.001). Considering the RPE in specific areas, no differences were observed between the upper and lower body (p = 0.743). We conclude that the BJJ simulated tournament generated a decrease of performance in both upper and lower limbs and provoked a progressive increase in the effort perception over the matches.     

The rating of perceived exertion predicts intermittent vertical jump demand and performance

The aims of this study were (a) to assess the ability of the rating of perceived exertion (RPE) to predict performance (i.e. number of vertical jumps performed to a fixed jump height) of an intermittent vertical jump exercise, and (b) to determine the ability of RPE to describe the physiological demand of such exercise. Eight healthy men performed intermittent vertical jumps with rest periods of 4, 5, and 6 s until fatigue. Heart rate and RPE were recorded every five jumps throughout the sessions. The number of vertical jumps performed was also recorded. Random coefficient growth curve analysis identified relationships between the number of vertical jumps and both RPE and heart rate for which there were similar slopes. In addition, there were no differences between individual slopes and the mean slope for either RPE or heart rate. Moreover, RPE and number of jumps were highly correlated throughout all sessions (r = 0.97-0.99; P < 0.001), as were RPE and heart rate (r = 0.93-0.97; P < 0.001). The findings suggest that RPE can both predict the performance of intermittent vertical jump exercise and describe the physiological demands of such exercise.     

Faculties of Education in Traditional Universities and Universities of the Third Age: A Partnership Model in Gerontagogy

This article discusses “Universities of the Third Age”, whose function is quite distinct from established universities' traditional role in teaching, research, and community services. Consequently, there is an urgent need to develop a model of partnership between traditional universities and Universities of the Third Age, ensuring better training for educators working with senior citizens. Determining the roles of teachers, supervisors, and students will facilitate greater cooperation, and allow for a linkage of Universities of the Third Age (U3A) with traditional faculties of education, as well as further refinement of the theoretical and practical professional training of future educators of older people.     

Fault reconstruction using a LPV sliding mode observer for a class of LPV systems

This paper proposes a new sliding mode observer for fault reconstruction, applicable for a class of linear parameter varying (LPV) systems. Observer schemes for actuator and sensor fault reconstruction are presented. For the actuator fault reconstruction scheme, a virtual system comprising the system matrix and a fixed input distribution matrix is used for the design of the observer. The fixed input distribution matrix is instrumental in simplifying the synthesis procedure to create the observer gains to ensure a stable closed-loop reduced order sliding motion. The ‘output error injection signals’ from the observer are used as the basis for reconstructing the fault signals. For the sensor fault observer design, augmenting the LPV system with a filtered version of the faulty measurements allows the sensor fault reconstruction problem to be posed as an actuator fault reconstruction scenario. Simulation tests based on a high-fidelity nonlinear model of a transport aircraft have been used to demonstrate the proposed actuator and sensor FDI schemes. The simulation results show their efficacy.     

Envisioning a critical social pedagogy of learning and work in a contemporary culture of cyclical lifelong learning

In Canada, current federal learning-and-work policy is focused on individual learner-worker development using an iteration of lifelong learning as cyclical. This policy aims to enhance the social as an effect of enhancing the economic. In this neoliberal milieu, cyclical lifelong learning has become not only a norm but also a culture and an attitude. Still, a current Canadian phenomenon indicates that increasing numbers of young adults are disengaging from participation in such learning that the federal government considers being a preventive measure. In discussing their withdrawal from what might be perceived as cyclical lifelong learning for control, I consider a particularly challenging case: the predicament of young adults in the Canadian province of Newfoundland and Labrador. To help us think about adequately addressing the dislocation they experience in life and work, I offer a Freire-informed vision of a critical social pedagogy of learning and work. This pedagogy calls for re-engendering the social in lifelong learning by revitalizing critical social concerns with historical awareness, hope, possibility, ethics, justice, democratic vision, learner freedom, critique, and intervention.