Effects of self-generated electric and magnetic fields in laser-generated fast electron propagation in solid materials: Electric inhibition and beam pinching

We present some experimental results which demonstrate the presence of electric inhibition in the propagation of relativistic electrons generated by intense laser pulses, depending on target conductivity. The use of transparent targets and shadowgraphic techniques has made it possible to evidence electron jets moving at the speed of light, an indication of the presence of self-generated strong magnetic fields

Corrigendum to Monitoring training load and fatigue in soccer players with physiological markers

In the introduction of the paper [1], it is stated that: ?Subjective measures such as the rating of perceived exertion (RPE) [6], for which players are asked to grade their own perceived load, could be used to quantify fatigue and training load?. However, as wisely described by Micklewright et al. [2]: ?? perceived exertion, or the subjective experience of how hard a physical task feels was felt, is quite different compared to perceived fatigue, which we argue is a feeling of diminishing capacity to cope with physical or mental stressors (either imagined or real). (?) while we acknowledge the excellent psychophysical properties of most perceived exertion scales, measurements of exertion should only be used for their intended purpose of quantifying how hard a task feels. This suggests that perceived exertion scales should not be used to measure fatigue or fatigability?. Therefore we would like to acknowledge that RPE could be used to quantify training load but it is not specifically targeting fatigue, as it has been stated in our and in other manuscripts

Relationship between fluid loss variation and physical activity during official games in elite soccer players

The aim of the present study was to analyse the relationships between fluid ingestion, changes in body mass and physical activity amongst elite soccer players. 32 elite French soccer players were divided into six playing positions: goalkeepers (GK), central defenders (CD), full backs (FB), central midfielders (CM), wide midfielders (WM) and forwards (FW) and participated in official friendly matches within two consecutive pre-season periods. Body mass changes and fluid ingestion were recorded before, during and just after the matches. Time-motion characteristics were also analysed. Players ingested 1.4±0.6 L of fluids during matches and lost 1.4±0.6 kg at the end of the games. WM lost more weight than GK, FB and FW (p<0.05) and CM lost more weight than GK (p<0.05). Furthermore, CD covered significantly less total distance, high (HI) and very high intensity running distance than all other playing positions excluding GK (p<0.05); and WM covered greater distances at HI than all other playing positions. No differences were found in fluid ingestion between playing positions. The results of this study indicate that sweat loss was significantly different when comparing across various playing positions. As a result, sweat lost may be more influenced by HI activity during a game than other physical activity within game scenarios. Therefore, players with the highest amount of HI activities during a match should even more pay attention to their rehydration.El objetivo del presente estudio consistió en analizar las relaciones entre la ingesta de líquidos, cambios en la composición corporal y en la actividad física en jugadores de élite. La muestra estaba compuesta por 32 jugadores franceses de élite divididos en seis posiciones de juego: porteros (P), defensas centrales (DC), laterales (L), mediocentros (M), Extremos (E) y delanteros (D). Se registraron en dos partidos amistosos jugados en la pretemporada. Los cambios en composición corporal y la ingesta de líquidos se realizaron antes, durante y después de los partidos. Los datos sobre rendimiento físico también fueron registrados. Los jugadores tomaron 1.4±0.6 L de líquidos durante los partidos y perdieron 1.4±0.6 L al terminar los mismos. Los E perdieron más peso que los P, L y D (p<0.05) y los M más que los P (p<0.05). Asimismo, los DC corrieron menos distancia total, a alta (HI) y muy alta intensidad que el resto de puestos de juego, con excepción de los P (p<0.05); y los E recorrieron más distancias a HI que los otros puestos de juego. No se encontraron diferencias sobre la ingesta de líquidos entre puestos de juego. Los resultados del estudio indican que la pérdida de líquidos por sudor fue diferente entre los puestos de juego. De modo que la pérdida de sudor pudo afectar la actividad a HI durante el partido por encima de otros parámetros físicos en los escenarios de competición. Por lo tanto, los jugadores con performance; fatigue; drinking; dehydration; football; playing position performance; fatigue; drinking; dehydration; football; playing positionmayor actividad a HI en los partidos deberían tener una mayor atención a los aspectos de rehidratación

Collaboration between non-profit organizations in the provision of social services in Canada Working together or falling apart?

SIGLEAvailable from British Library Document Supply Centre-DSC:7755.0403(RP9827) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

A combined experimental and numerical investigation of the flow in a heated rotor/stator cavity, with a centripetal injection

Communication to : 44th ASME gas turbine aeroengine technical congress, exposition and users symposium, Indianapolis (USA), June 07-10, 1999SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1999 n.84 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Effects of self-generated electric and magnetic fields in laser-generated fast electron propagation in solid materials: Electric inhibition and beam pinching

We present some experimental results which demonstrate the presence of electric inhibition in the propagation of relativistic electrons generated by intense laser pulses, depending on target conductivity. The use of transparent targets and shadowgraphic techniques has made it possible to evidence electron jets moving at the speed of light, an indication of the presence of self-generated strong magnetic fields