Description des caractéristiques des situations d'apprentissage et de perfectionnement tactiques au soccer et au hockey sur glace.

Le développement des performances des joueurs en sports collectifs d'invasion de territoire est une tâche complexe qui ne peut se faire qu'en jouant des matchs. C'est principalement grâce aux Situations d'Apprentissage et de Perfectionnement (SAP) pendant les périodes d'entrainement que les entraineurs offrent des activités visant le développement des principales composantes de la performance des joueurs (physique, technique, stratégique, tactique). Parmi toutes ces composantes, la tactique demeure un élément particulièrement difficile à faire apprendre car ces actions doivent continuellement s'adapter en fonction de celles des coéquipiers et adversaires. Or, la littérature scientifique offre peu d'informations sur la manière d'analyser les SAP en sport compétitif, et aucune étude récente décrit clairement la proportion de temps ou d'activités accordée aux apprentissages tactiques qui sont à la base de ces sports collectifs. Ce projet vise d'abord à créer et valider une procédure de catégorisation des SAP permettant de décrire et de comparer les activités offertes pendant les séances d'entrainement. Ensuite, l'étude vise à décrire les caractéristiques des SAP et exercices offerts aux athlètes de hockey sur glace et de soccer afin de quantifier et qualifier le temps passé au développement des habiletés tactiques. L'analyse de contenus de séances (n=29 au hockey et n=34 au soccer) a permis de créer un Arbre décisionnel comprenant une série de questions permettant de catégoriser toutes formes de SAP offertes aux joueurs de sports collectifs. À partir de cette catégorisation, une description détaillée des SAP offertes aux joueurs est illustrée. Les résultats indiquent que les aspects tactiques sont peu entrainés en générale, bien que des différences importantes existent entre les équipes observées. Les conclusions observées démontrent que la proportion ou la qualité des SAP tactiques est faible comparativement aux autres SAP et peu cohérente avec les fondements de ces sports.Little information is available regarding how to categorize Learning Activities (LA) proposed to athletes during training sessions in competitive team sport. Due to the importance of game fundamentals in team sports, teaching tactical skills should predominate all other components of player performance (physical, technical, strategic, tactical). However, observation of coaches' training sessions seems to show that coaches use few tactical SAPs compared to technical or physical conditioning activities. The purpose of this study was to create a categorization framework that would allow the description and comparison of the characteristics of SAPs offered to athletes in ice hockey and soccer in competitive teams. Analysis of practice sessions (N = 29 in ice hockey and N = 34 in soccer) made it possible to create a Decision Tree comprising of a series of questions that enables the categorization of all forms of SAPs proposed to team sport athletes. This framework was then used to analyze 421 SAPs used by coaches in these two sports. Results of the analysis showed that the proportion or quality of tactical exercises were low compared to technical skills SAPs or physical conditioning exercises. In conclusion, the Decision tree makes it possible to categorize most learning situations or exercises offered to athletes. In addition, the results demonstrate the importance of new pedagogical strategies allowing a better development of tactical skills

L’utilisation de la technique des incidents critiques pour favoriser la réflexion de joueurs en sports collectifs

L’apprentissage d’Habiletés tactiques en sports collectifs doit être basé sur la pratique de situations de jeu où les joueurs sont libres de prendre des décisions afin d’exécuter des actions appropriées au contexte. Pour ce faire, ils doivent pouvoir prendre du recul pour comprendre le jeu et choisir la meilleure option à chaque instant. Ceci est particulièrement important en sport compétitif où une mauvaise décision peut mener à la défaite. Or, le temps nécessaire pour effectuer cette réflexion est limité tant lors de matchs que lors de séances d’entraînement. Le but de cette étude est de décrire comment des joueurs ont utilisé la technique des incidents critiques (TIC) pour décrire des situations de jeu vécues lors de matchs du calendrier de compétition. Trois entraineurs ont invité leurs joueurs [football (n =36) et hockey sur glace (n =18)] à décrire des situations de jeu qu’ils considéraient Très efficaces (TE) ou Peu efficaces (PE)], pour le match qu’ils venaient de jouer, et de justifier leur point de vue. Les joueurs ont rapporté davantage de situations TE (n =289) que PE (n =117). La majorité des récits concernaient des actions tactiques individuelles offensives liées aux principes de jeu de marquer (n = 184) et progresser vers le but (n =239). Les constats de l’étude démontrent que l’utilisation de la TIC peut aider les joueurs à prendre du recul sur les situations vécues afin de mieux comprendre le jeu. Cette méthode aurait tout avantage à être utilisée régulièrement par les entraineurs qui privilégient une approche basée sur l’apprentissage par la compréhension du jeu.Teaching and learning tactical skills is essential to improving performance in team sport. A player’s understanding of the game is a valuable indication of the learning of these skills. This understanding is based on a reflection process where players need to analyse significant moment of the game. Unfortunately, the game itself, neither the exercises in practice sessions, gives enough occasions to player to be in that reflection process. The purpose of this study is to describe how competitive players can use the critical incident technique to describe tactical situations that have experienced during games. Fifty-four athletes [football (n =36) and ice hockey (n =18)] were asked by their coaches to describe game situations [Very Effective (TE) and/or Less effective (NE) tactical situation] they have experienced during games. Players were free to describe and explain in detail the reasons why they considered them significant situations. A validated procedure was used to ensure an objective classification of the incidents. Players reported more E (n =289) than NE (n =117) tactical situations. Majority of situations referred to individual and offensive tactical situations, in which attacking the opposite goal (n = 184) and progressing to the opposite goal (n =239) were most cited by players. This study suggest that the reflection process, associated with writing critical incidents, can help players and coaches to better understand the game in a Learning games through understanding approach

Identifying conditions for inducible protein production in E. coli: combining a fed-batch and multiple induction approach

BACKGROUND: In the interest of generating large amounts of recombinant protein, inducible systems have been studied to maximize both the growth of the culture and the production of foreign proteins. Even though thermo-inducible systems were developed in the late 1970's, the number of studies that focus on strategies for the implementation at bioreactor scale is limited. In this work, the bacteriophage lambda P(L )promoter is once again investigated as an inducible element but for the production of green fluorescent protein (GFP). Culture temperature, induction point, induction duration and number of inductions were considered as factors to maximize GFP production in a 20-L bioreactor. RESULTS: It was found that cultures carried out at 37°C resulted in a growth-associated production of GFP without the need of an induction at 42°C. Specific production was similar to what was achieved when separating the growth and production phases. Shake flask cultures were used to screen for desirable operating conditions. It was found that multiple inductions increased the production of GFP. Induction decreased the growth rate and substrate yield coefficients; therefore, two time domains (before and after induction) having different kinetic parameters were created to fit a model to the data collected. CONCLUSION: Based on two batch runs and the simulation of culture dynamics, a pre-defined feeding and induction strategy was developed to increase the volumetric yield of a temperature regulated expression system and was successfully implemented in a 20-L bioreactor. An overall cell density of 5.95 g DW l(-1 )was achieved without detriment to the cell specific production of GFP; however, the production of GFP was underestimated in the simulations due to a significant contribution of non-growth associated product formation under limiting nutrient conditions

Causes of decoupling between larval supply and settlement and consequences for understanding recruitment and population connectivity

Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Journal of Experimental Marine Biology and Ecology 392 (2010): 9-21, doi:10.1016/j.jembe.2010.04.008.Marine broadcast spawners have two-phase life cycles, with pelagic larvae and benthic adults. Larval supply and settlement link these two phases and are crucial for the persistence of marine populations. Mainly due to the complexity in sampling larval supply accurately, many researchers use settlement as a proxy for larval supply. Larval supply is a constraining variable for settlement because, without larval supply, there is no settlement. Larval supply and settlement may not be well correlated, however, and settlement may not consistently estimate larval supply. This paper explores the argument that larval supply (i.e., larval abundance near settlement sites) may not relate linearly to settlement. We review the relationship between larval supply and settlement, from estimates and biases in larval supply sampling, to non-behavioral and behavioral components, including small-scale hydrodynamics, competency, gregarious behavior, intensification of settlement, lunar periodicity, predation and cannibalism. Physical and structural processes coupled with behavior, such as small-scale hydrodynamics and intensification of settlement, sometimes result in under- or overestimation of larval supply, where it is predicted from a linear relationship with settlement. Although settlement is a function of larval supply, spatial and temporal processes interact with larval behavior to distort the relationship between larval supply and settlement, and when these distortions act consistently in time and space, they cause biased estimates of larval supply from settlement data. Most of the examples discussed here suggest that behavior is the main source of the decoupling between larval supply and settlement because larval behavior affects the vertical distribution of larvae, the response of larvae to hydrodynamics, intensification of settlement, gregariousness, predation and cannibalism. Thus, larval behavior seems to limit broad generalizations on the regulation of settlement by larval supply. Knowledge of the relationship is further hindered by the lack of a well founded theoretical relationship between the two variables. The larval supply- settlement transition may have strong general consequences for population connectivity, since larval supply is a result of larval transport, and settlement constrains recruitment. Thus, measuring larval supply and settlement effectively allows more accurate quantification and understanding of larval transport, recruitment and population connectivity.JP would like to thank WHOI Ocean Life Institute for partial funding. FP’s contribution is based upon research supported by the South African Research Chairs Initiative of the Department of Science and Technology and National Research Foundation

New insights into the huddling dynamics of emperor penguins

International audienceSocial thermoregulation is a cooperative strategy in which animals actively aggregate to benefit from thewarmth of conspecifics in response to low ambient temperatures. Emperor penguins, Aptenodytes forsteri,use this behaviour to ensure their survival and reproduction during the Antarctic winter. An emperorpenguin colony consists of a dynamic mosaic of compact zones, the so-called huddles, included in alooser network of individuals. To maximize energy savings, birds should adjust their huddling behaviouraccording to environmental conditions. Here, we examined the dynamics of emperor penguin aggregations,based on photo and video records, in relation to climatic factors. Environmental temperature,wind and solar radiation were the main factors contributing to huddle formation. The analysis of individualmovements showed that birds originating from loose aggregations continually joined huddles.Sometimes, a small number of birds induced a movement that propagated to the entire huddle, causingits breakup within 2 min and releasing birds, which then integrated into looser aggregations. Differentparts of the colony therefore appeared to continually exchange individuals in response to environmentalconditions. A likely explanation is that individuals in need of warmth join huddles, whereas individualsseeking to dissipate heat break huddles apart. The regular growth and decay of huddles operates aspulses through which birds gain, conserve or lose heat. Originally proposed to account for reducingenergy expenditure, the concept of social thermoregulation appears to cover a highly dynamic phenomenonthat fulfils a genuine regulatory function in emperor penguins

Comparison of four-year toxicities and local control of ultra-hypofractionated vs moderate-hypofractionated image guided prostate radiation with HDR brachytherapy boost: A phase I-II single institution trial

Purpose/Objective(s): To analyze the long term efficacy and safety of an ultra-hypofractionated (UHF) radiation therapy prostate treatment regimen with HDR brachytherapy boost (BB) and compare it to moderate-hypofractionated regimens (MHF). Materials/Methods: In this single arm, prospective monocentric study, 28 patients with intermediate risk prostate cancer were recruited in an experimental treatment arm of 25 Gy in 5 fractions plus a 15 Gy HDR BB. They were then compared to two historical control groups, treated with either 36 Gy in 12 fractions or 37.5 Gy in 15 fractions with a similar HDR BB. The control groups included 151 and 311 patients respectively. Patient outcomes were reported using the International Prostate Symptom Score (IPSS) and Expanded Prostate Index Composite (EPIC-26) questionnaires at baseline and at each follow-up visit. Results: Median follow-up for the experimental arm was 48.5 months compared to 47 months and 60 months compared to the 36/12 and 37,5/15 groups respectively. The IPSS and EPIC scores did not demonstrate any significant differences in the gastrointestinal or genitourinary domains between the three groups over time. No biochemical recurrence occurred in the UHF arm as defined by the Phoenix criterion. Conclusion: The UHF treatment scheme with HDR BB seems equivalent to standard treatment arms in terms of toxicities and local control. Randomized control trials with larger cohorts are ongoing and needed to further confirm our findings