Accuracy and functional variability in elite and developing fast bowlers

Objectives The relationship between performance variability and accuracy in cricket fast bowlers of different skill levels under three different task conditions was investigated. Bowlers of different skill levels were examined to observe if they could adapt movement patterns to maintain performance accuracy on a bowling skills test. Design 8 national, 12 emerging and 12 junior pace bowlers completed an adapted version of the Cricket Australia bowling skills test, in which they performed 30 trials involving short (n = 10), good (n = 10), and full (n = 10) length deliveries. Methods Bowling accuracy was recorded by digitising ball position relative to the centre of a target. Performance measures were mean radial error (accuracy), variable error (consistency), centroid error (bias), bowling score and ball speed. Radial error changes across the duration of the skills test were used to record accuracy adjustment in subsequent deliveries. Results Elite fast bowlers performed better in speed, accuracy, and test scores than developing athletes. Bowlers who were less variable were also more accurate across all delivery lengths. National and emerging bowlers were able to adapt subsequent performance trials within the same bowling session for short length deliveries. Conclusions Accuracy and adaptive variability were key components of elite performance in fast bowling which improved with skill level. In this study, only national elite bowlers showed requisite levels of adaptive variability to bowl a range of lengths to different pitch locations.

Distribution of toxins in various tissues of crucian carp intraperitoneally injected with hepatotoxic microcystins

An acute toxicity experiment was conducted to examine the distribution and depuration of microcystins (MCS) in crucian carp (Carassius aurutus) tissues. Fish were injected intraperitoneally with extracted MCs at a dose of 200 mu g MC-LR (where L = leucine and R = arginine) equivalent/kg body weight. Microcystin concentrations in various tissues and aquaria water were analyzed at 1, 3, 12, 24, and 48 h postinjection using liquid chromatography coupled with mass spectrometry. Microcystins were detected mainly in blood (3.99% of injected dose at 1 h), liver (1.60% at I h), gonad (1.49% at 3 h), and kidney (0.14% at 48 h). Other tissues, such as the heart, gill, gallbladder, intestine, spleen, brain, and muscle, contained less than 0.1% of the injected MCs. The highest concentration of MCs was found in blood (526-3,753 ng/g dry wt), followed by liver (103-1,656 ng/g dry wt) and kidney (279-1,592 ng/g dry wt). No MC-LR was detectable in intestine, spleen, kidney, brain, and muscle, whereas MC-RR was found in all examined fish tissues, which might result from organ specificity of different MCs. Clearance of MC-RR in brain tissue was slow. In kidney, the MC-RR content was negatively correlated with that in blood, suggesting that blood was important in the transportation of MC-RR to kidney for excretion.

Programas de educación para la tolerancia y prevención de la violencia en los jóvenes.

Se presentan programas educativos que analizan las causas que pueden conducir a la intolerancia y a la violencia en los jóvenes y las capacidades que pueden promoverse para prevenir estos problemas. Se basan en cuatro procedimientos que pueden ser aplicados a cualquier contenido educativo: discusiones y debates entre compañeros, aprendizaje cooperativo, resolución de conflictos y democracia participativa. Se describen las pautas de aplicación de estos programas en centros de educación secundaria, resumiendo sus distintos componentes y su relación con los niveles de concreción del currículo. Una serie de guías informativas y materiales complementarios, documentos de prensa y audivisuales y manifiestos, se estructuran en siete unidades temáticas. Cada documento audiovisual recoge una selección de las diversas actividades propuestas, su valoración por profesores y alumnos y su análisis en el contexto del curso de formación de profesores a través del cual se desarrollaron y aplicaron. Se incluyen los instrumentos de evaluación e investigaciones llevadas a cabo para desarrollar y comprobar estos programas y el modelo de formación de profesores empleado.

Los materiales didácticos en el área de Lengua y Literatura : criterios de selección y elaboración.

En el contexto del área de Lengua y Literatura para Educación Primaria y ESO, se exponen diversos criterios para la selección y elaboración de materiales didácticos. Se señala la relación existente, en cuanto a objetivos, contenidos, matodología y evaluación, entre el currículo y los materiales didácticos que se emplean en el aula. Se aborda el tratamiento a la diversidad, proponiendo estrategias para la selección de materiales.

Madeleine Ten Have, Brustbild

Signatur des Originals: S 36/F00724