Réduction de l’anxiété en laboratoire d’enseignement en éducation physique

L'étude vise à comparer l'efficacité de deux traitements de réduction de l'anxiété chez des étudiants universitaires en éducation physique vivant leurs premières expériences d'enseignement: la relaxation et la restructuration cognitive. L'évaluation de l'anxiété se fait à partir de questionnaires administrés dans le cadre de trois laboratoires d'enseignement. La comparaison est établie entre deux groupes expérimentaux (relaxation ou restructuration cognitive) et deux groupes de contrôle. Quelques différences significatives sont trouvées pour certains paramètres évalués. On remarque que la relaxation semble contribuer à un meilleur contrôle du niveau d'anxiété des sujets lors de leur laboratoire d'enseignement. On propose des moyens concrets susceptibles de réduire l'anxiété chez les futurs intervenants en milieu scolaire.The objective of this study is to compare the efficiency of two treatments for reducing anxiety in university level physical education students during their first teaching experiences: relaxation techniques and cognitive restructuring techniques. A series of questionnaires to evaluate anxiety was administered during three teaching laboratory activities. A comparison of the results of two experimental groups (relaxation and cognitive restructuring) with those of two control groups was found to produce several significant differences for some of the parameters examined. The authors note that relaxation tech- niques appear to contribute in producing a better control of anxiety for subjects during the laboratory teaching experience. They propose specific methods aimed at reducing anxiety in future teachers.Se commparô la eficacia de dos tratamientos de reducción de la ansiedad en los estudiantes universitarios en education fisica que viven sus primeras experiencias de ensenanza: la relajación y la reestructuraciôn cognitiva. La evaluación de la ansiedad se hace a partir de cuestionarios administrados en el contexto de très laboratorios de ensenanza. Se establece una comparación entre dos grupos expérimentales (relajación o reestructuraciôn cognitiva) y dos grupos contróles. En ciertos parámetros evaluados se encuentran algunas diferencias significativas. Se constata que la relajación parece contribuir a un mejor control del nivel de ansiedad de los sujetos durante los laboratorios de ensenanza. Se proponen medios concretos susceptibles de reducir la ansiedad en los futuros profesores.Die Untersuchung will die Wirksamkeit zweier Behandlungsmethoden zur Verminderung der Angst bei Universitätsstudenten der Korpererziehung vergleichen, die ihre ersten Unterrichtsversuche machen: Entspannung und Verbesserung der Denkweise. Der Grad der Angst wird mithilfe von Fragebôgen gemessen, die in drei Unterrichtslabors vorgelegt werden. Der Vergleich wird durchgeführt zwischen zwei Experimentalgruppen (Entspannung und Umdenken) und zwei Kontrollgruppen. Einige bedeutsame Unterschiede wurden fur gewisse der gemessenen Parameter gefunden. Man bemerkt, dass die Entspannung mehr zu einer besseren Beherrschung der Angst beiträgt, wenn die Teilnehmer den Unterrichtsversuch halten. Man schlägt konkrete Mittel vor, die die Angstgefühle bei den künftigen Lehrkräften vermindern kônnen

Mercury and methylmercury concentrations in high altitude lakes and fish (Arctic charr) from the French Alps related to watershed characteristics

International audienceTotal mercury (THg) andmethylmercury (MeHg) concentrations were measured in the muscle of Arctic charr (Salvelinus alpinus) and in the water column of 4 lakes that are located in the French Alps. Watershed characteristics were determined (6 coverage classes) for each lake in order to evaluate the influence of watershed composition on mercury and methylmercury concentrations in fish muscle and in the water column. THg and MeHg concentrations in surface water were relatively low and similar among lakes and watershed characteristics play a major role in determining water column Hg and MeHg levels. THg muscle concentrations for fish with either a standardized length of 220 mm, a standardized age of 5 years or for individualuals did not exceed the 0.5 mg kg−1 fish consumption advisory limit established for Hg by the World Health Organization (WHO, 1990). These relatively low THg concentrations can be explained by watershed characteristics, which lead to short Hg residence time in the water column, and also by the short trophic chain that is characteristic of mountain lakes. Growth rate did not seem to influence THg concentrations in fish muscles of these lakes and we observed no relationship between fish Hg concentrations and altitude. This study shows that in the French Alps, high altitude lakes have relatively low THg and MeHg concentrations in both the water column and in Arctic charr populations. Therefore, Hg does not appear to present a danger for local populations and the fishermen of these lakes

Design of a 3D printer head for additive manufacturing of sugar glass for tissue engineering applications

Additive manufacturing is now considered as a new paradigm that is foreseen to improve progress in many fields. The field of tissue engineering has been facing the need for tissue vascularization when producing thick tissues. The use of sugar glass as a fugitive ink to produce vascular networks through rapid casting may offer the key to vascularization of thick tissues produced by tissue engineering. Here, a 3D printer head capable of producing complex structures out of sugar glass is presented. This printer head uses a motorized heated syringe fitted with a custom made nozzle. The printer head was adapted to be mounted on a commercially available 3D printer. A mathematical model was derived to predict the diameter of the filaments based on the printer head feed rate and extrusion rate. Using a 1 mm diameter nozzle, the printer accurately produced filaments ranging from 0.3 mm to 3.2 mm in diameter. One of the main advantages of this manufacturing method is the self-supporting behaviour of sugar glass that allows the production of long, horizontal, curved, as well as overhanging filaments needed to produce complex vascular networks. Finally, to establish a proof of concept, polydimethylsiloxane was used as the gel matrix during the rapid casting to produce various “vascularized” constructs that were successfully perfused, which suggests that this new fabrication method can be used in a number of tissue engineering applications, including the vascularization of thick tissues

Progression of Hypertrophy and Myocardial Fibrosis in Aortic Stenosis: A Multicenter Cardiac Magnetic Resonance Study

Background: Aortic stenosis is accompanied by progressive left ventricular hypertrophy and fibrosis. We investigated the natural history of these processes in asymptomatic patients and their potential reversal post-aortic valve replacement (AVR).  Methods: Asymptomatic and symptomatic patients with aortic stenosis underwent repeat echocardiography and magnetic resonance imaging. Changes in peak aortic-jet velocity, left ventricular mass index, diffuse fibrosis (indexed extracellular volume), and replacement fibrosis (late gadolinium enhancement [LGE]) were quantified.  RESULTS: In 61 asymptomatic patients (43% mild, 34% moderate, and 23% severe aortic stenosis), significant increases in peak aortic-jet velocity, left ventricular mass index, indexed extracellular volume, and LGE mass were observed after 2.1±0.7 years, with the most rapid progression observed in patients with most severe stenosis. Patients with baseline midwall LGE (n=16 [26%]; LGE mass, 2.5 g [0.8–4.8 g]) demonstrated particularly rapid increases in scar burden (78% [50%–158%] increase in LGE mass per year). In 38 symptomatic patients (age, 66±8 years; 76% men) who underwent AVR, there was a 19% (11%–25%) reduction in left ventricular mass index (P<0.0001) and an 11% (4%–16%) reduction in indexed extracellular volume (P=0.003) 0.9±0.3 years after surgery. By contrast midwall LGE (n=10 [26%]; mass, 3.3 g [2.6–8.0 g]) did not change post-AVR (n=10; 3.5 g [2.1–8.0 g]; P=0.23), with no evidence of regression even out to 2 years.  Conclusions: In patients with aortic stenosis, cellular hypertrophy and diffuse fibrosis progress in a rapid and balanced manner but are reversible after AVR. Once established, midwall LGE also accumulates rapidly but is irreversible post valve replacement. Given its adverse long-term prognosis, prompt AVR when midwall LGE is first identified may improve clinical outcomes