Physical profiles of elite,sub-elite,regional and age-group netballers

Physical profile data from elite, sub-elite, regional, under 21s (U21), under 19s (U19) and under 17s (U17) (n = 845) players from a state netball association in Australia were analysed. Within season changes were examined for the elite and sub-elite players. Longitudinal changes were examined for the elite across four consecutive netball seasons.

Elite were significantly older (24.3 ± 3.4years), taller (182.4 ± 7.2cm) and heavier (73.42 ± 6.95kg) than other playing levels (p < 0.001, ES 0.49–3.26) and had higher vertical jump (VJ) data compared to all groups (p < 0.001, ES 0.47–0.93). U17’s were significantly faster than elite, sub-elite and U19 players over 5m (p < 0.05, ES 0.36–0.58) while elite were faster over 20m compared to all groups (p < 0.01, ES 0.45–0.72). Elite achieved a greater distance (1350.8m; p < 0.05, ES 0.32–0.50) in the Yo-YoIRT1 compared to the sub-elite, regional, U19 and U17. VJ height significantly increased from the 2014 (51.6 ± 4.8cm) to the 2017 season (59.6 ± 6.3cm) for the elite players (p < 0.01, ES 1.18). Yo-YoIRT1 test scores increased significantly between the pre-season and in-season phases (p < 0.05, ES 0.17).     

Remote ischaemic preconditioning shortens QT intervals during exercise in healthy subjects

The protective action of remote ischaemic preconditioning (RIPC) has been demonstrated in the context of surgical interventions in cardiology. Application of RIPC to sports performance has been proposed, but its effect on the electrocardiogram (ECG) during exercise remains unknown. This exploratory study aims to measure the changes in ventricular repolarization observed during exercise following RIPC in healthy subjects. In an experimental randomized crossover study, 17 subjects underwent two bouts of constant load exercise tests at 75% and 115% of gas exchange threshold (GET). Prior to exercise, they were allocated to either control or RIPC intervention with four cycles of 5?min of ischaemia followed by 5?min of reperfusion. ECG was continuously recorded during the protocol. QT and RR intervals were measured every 30?s (on an average tracing of the preceding 10?s). Although the time course of RR intervals did not differ between the two interventions (p?=?.56 at 75% GET and p?=?.74 at 115% GET), a significant shortening of QT intervals (measured from Q onset to T end) was observed during exercise (mean?±?standard deviation of RIPC vs. control: ?32?±?19?ms at 75% GET (p?p?p?p?相似文献   

Δ-distance: A family of dissimilarity metrics between images represented by multi-level feature vectors

This article presents the Δ-distance, a family of distances between images recursively decomposed into segments and represented by multi-level feature vectors. Such a structure is a quad, a quin or a nona-tree resulting from a fixed and arbitrary image partition or from an image segmentation process. It handles positional information of image features (e.g. color, texture or shape). Δ-distance is the generalized form of dissimilarity measures between multi-level feature vectors. Using different weights on tree nodes and different distances between nodes, distances between trees or visual similarity between images can be computed based on the general definition of Δ. In this article, we present three Δ-based distance families: two families of distances between tree structures, called -distance( for Tree) and -distance ( for Segment), and a family of visual distances between images, called ( for Visual). The -distance visually compares two images using their tree representation and the other two distances compare the tree structures resulting from image segmentation. Moreover, we show how existing distances between multi-level feature vectors appear to be particular cases of the Δ-distance     

Capacité cognitive,sentiment d’auto-efficacité et autorégulation

Feelings of self-efficacy have been the object of several studies that have confirmed its ability to predict performance in different contexts. Yet few studies have been conducted using cognitive or academic tasks in which it is more difficult to clearly distinguish self-efficacy from competence. The present study aims to study the moderating role of cognitive capacity in determining the relationship between self-efficacy and on-line self-regulation observed while solving a verbal concept formation task. In order to distinguish self-efficacy from competence, 44 subjects were selected based on the results of their SSPI; these results of which are related to comprehension ability. Analyses of results allow us to observe that, when compared to subjects who consider themselves less efficacious, subjects who have strong feelings of self-efficacy have a higher success rate, are more certain of these successes and reject fewer correct hypotheses, no matter what their cognitive ability. These results once again bring to light the relative independance of cognitive ability and motivational determinants of a person’s actual accomplishments.     

La Psicología de Vygotski: sobre la larga proyección de una corta biografía

RESUMEN

Se presenta el contexto histórico y los antecedentes familiares, culturales y sociales en los que surge la figura de Vygotski y se hace una descripción minuciosa de su obra, de sus implicaciones y contribuciones a la Psicología Científica: su teoría sobre las funciones superiores en el hombre, la actividad instrumental como unidad de análisis de estos procesos superiores, los estudios sobre génesis y desarrollo de los procesos cognitivos y las variaciones culturales, la “zona de desarrollo potencial”, sus aportaciones a la pedagogía y al estudio de las deficiencias, su teoría de la organización neurofisiológica, sus aportaciones a una teoría general del desarrollo y su teoría de la génesis del pensamiento verbal y la función reguladora del lenguaje. Se citan algunas críticas a Vygotski y se formulan algunas implicaciones teóricas no formuladas explícitamente en su teoría.     

Représentations et fonctionnements cognitifs dans une recherche de panne d’un système d’allumage en mecanique-auto

Fault finding is a puzzling task, at work and in technical and professional training. Our purpose is to contribute to an analysis of the required competencies and mainly to a characterisation of the evolution steps in knowledge and action organisation from novice to expert. Eight grown-up preparing a professional certificate in engine mecanics were observed and filmed while they were working out the diagnosis of an ignition trouble on a real equipment. The theory of functionning registers (deducted from Piaget’s theory) is considered as a relevant frame for our activity analysis. So, four competencies patterns has been outlined on the basis of errors extension, circuit functionning representations which were infered from schema interpretations, and trouble-shooting strategies denoted by control procedures. Some consequences about training are examined.     

Investigation of blood pulse PPG signal regulation on toe effect of body posture and lower limb height

Objective: To study the regulation of blood pulse volume via photoplethysmography (PPG) signal detected from toe, while the lower limb is passively raised in different height positions. Methods: Use a modified non-invasive PPG technique to detect the blood pulse signal on toe with infrared (IR) photo sensor. A protocol consisting of two postures, i.e., supine and 45° reclining, was designed to conduct laboratory trial in this study. During the period of performing the protocol of these postures, the lower limb was passively raised from the heights of 10 cm to 60 cm randomly and individually with sponge blocks underneath the foot. Results: In the supine posture, the higher the foot was passively raised, the more the blood PPG signal decreased. In the 45° reclining posture, the blood PPG signal increased at the beginning and then decreased in the foot height position from 10 cm to 60 cm. In both postures the normalized AC signal changes significantly while the normalized DC signal changes little. Conclusion: The toe PPG signals can obviously indicate the regulated blood volume change with the designated postural procedures due to the heart level position.     

Exploration De La Résilience éducationnelle Chez Des Enseignants

AN EXPLORATION OF THE EDUCATIONAL RESILIENCE OF TEACHING STAFF – This study focuses on the degree of resilience displayed by teaching staff with the aim of promoting their professional development and preventing job-related exhaustion. Seven underprivileged schools in Montreal were selected, and 24 teaching staff with contrasting personal profiles were interviewed on the subject of their work. The Alceste software was used to analyse the conversations, which revolved around techniques applied when dealing with critical incidents. The main analysis identified five different discourses among the respondents. Three of these were associated with the more resilient of the teachers and two were associated with the more vulnerable ones. Resilient teaching staff characteristically discussed dealing with aggressive behaviour, the teaching-learning relationship and the subject of social relationships, whereas vulnerable teaching staff focused on work beyond the classroom, people in positions of higher authority and the community. The authors note that teachers who are just embarking on their careers appear more vulnerable than more experienced teaching staff, which suggests that more resources should be provided to support teachers in their profession.     

Comment on Elbers' article: Which competence? For whom? For what?

In reaction to Elbers' paper, several comments are made concerning the unit of analysis used to observe children's cognitive activity, the nature of the competence assessed, and the role of the task, or the object of knowledge, in which the child and the adult interact. It is argued that the testing situation is a social event in which the adult and the child interact on a specific object and negotiate a common interpretation of the task and the situation. From this perspective, the testing situation appears to be a learning situation in which new knowledge is acquired.