Mechanical and EMG responses of the vastus lateralis and changes in biochemical variables to isokinetic exercise in endurance and power athletes     

Rainoldi A  Gazzoni M  Merletti R  Minetto MA 《Journal of sports sciences》2008,26(3):321-331

Twelve endurance athletes and six power athletes performed fatiguing isokinetic knee flexions/extensions. Isokinetic torque was recorded during the exercise. Isometric torque, cortisol and lactate responses, electromyographic (EMG) mean power frequency, average rectified value, and conduction velocity were analysed before and after the isokinetic exercise to determine correlations between electrophysiological variables and mechanical performances and/or blood concentrations of biomarkers in the two groups of athletes. The EMG variables were estimated from signals recorded from the vastus lateralis in both voluntary and electrically elicited isometric contractions. Power athletes recorded higher values than endurance athletes for the following variables: pre-exercise isometric maximal voluntary contraction (MVC), isokinetic MVC, rate of mechanical fatigue during isokinetic contractions, pre - post exercise variations and recovery times of conduction velocity and mean power frequency, and lactate concentrations. Moreover, conduction velocity overshooting was observed in endurance athletes during the recovery phase after exercise. The correlation analyses showed that the higher the rate of mechanical fatigue, the higher the lactate production and the reduction in conduction velocity due to the exercise.  相似文献   

Microtextural and microchemical studies of hydraulic ancient mortars: Two analytical approaches to understand pre-industrial technology processes     

Maria Pia Riccardi  Marco Lezzerini  Federico Car  Marco Franzini  Bruno Messiga 《Journal of Cultural Heritage》2007,8(4):350-360

Two different analytical approaches have been taken into account to investigate the role of Si-rich phases in enhance hydraulic reactions of bedding mortar mixtures from San Lorenzo Church in Milan (Northern Italy) and from the Medicean Aqueduct in Pisa (Central Italy). In the first case, mortars show clear hydraulic type reactions in the form of coronal layers between the reacting additive and the binder mass. In the second one, the hydraulic reactions do not develop visible mineral phases and processes have been inferred from chemical, mineralogical analyses and mass balance calculation. The microstructural studies not always are sufficient to understand the complex dynamics of reaction attained during pre-industrial manufacturing processing of mortars and related binders. In fact, if the reacting raw materials are fine-grained and/or have remarkable chemical reactivity, no relicts are preserved by mortar microtextures.  相似文献   

Physiological characteristics of America's Cup sailors   总被引：2，自引：0，他引：2  

Bernardi M  Quattrini FM  Rodio A  Fontana G  Madaffari A  Brugnoli M  Marchetti M 《Journal of sports sciences》2007,25(10):1141-1152

The aim of this study was to assess the physiological profile of America's Cup grinders and mastmen, by measuring energy expenditure during sailing and assessing their aerobic and anaerobic fitness. The study focused on estimating the energy used during grinding activity, by measuring oxygen uptake (VO(2)) during sail setting in real sailing conditions. In the laboratory, using an arm-cranking ergometer, we measured VO(2peak) during an incremental maximal exercise test and total energy expended during the effort and recovery phases of an all-out test that simulated grinding activity, in six grinders and mastmen and ten sailors of the same crew. Total energy used during grinding corresponded to 45% (s = 9) and 51% (s = 5) of that used in the all-out test (234 kJ, s = 21.7) for tacks and gybes, respectively. In both grinding activity and the all-out test, VO(2) increased during and after the effort. The "VO(2) top value" was 53% (s = 8.6), 68% (s = 5.5), and 78% (s = 3.1) of VO(2peak) (4.7 l . min(-1), s = 0.43) in tacks, gybes, and the all-out test, respectively. During fast sequences of grinding activity, the "VO(2) top value" reached 65% (s = 7.1) VO(2peak) in tacks and 91% (s = 3.3) VO(2peak) in gybes. Our results suggest that grinders and mastmen are characterized by a high anaerobic capacity but their performance can be improved by powering aerobic fitness, to increase this energy contribution to all-out efforts and to guarantee fast recovery when grinding activity is repeated with short rest intervals.  相似文献   

Editorial     

Marco Todeschini 《欧洲师范教育杂志》1993,16(2):91-94

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Editorial     

Marco Todeschini 《欧洲师范教育杂志》1992,15(3)

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'What Causes People to Vote for a Radical Right Party?' A Rejoinder to van der Brug and Fennema     

Giugni  Marco; Koopmans  Ruud 《Int. Journal of Public Opinion Research》2007,19(4):488-491

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Between Pragmatism and Legitimacy: Developments and dilemmas in teacher education in The Netherlands     

Mieke Lunenberg  Marco Snoek  Anja Swennen 《欧洲师范教育杂志》2000,23(3):251-260

In this paper, we describe how the shortage of teachers accelerates the development of Dutch teacher education in a more competence- and school-based direction. We address three themes. First, we note that Dutch teacher education institutes are taking initiatives to develop competence-based curricula and assessment. However, until now these developments have had a weak foundation. Secondly, it is clear that schools are developing and carrying out teacher improvement plans, but that student teachers are seldom part of these plans. Thirdly, the teacher educators in schools cannot meet the professional standards yet. Teacher educators in teacher education institutes also need time and support to adapt to new circumstances. However, there are promising developments in the right direction. Notre paper analyse les conséquences de la pénurie d'enseignants sur la formation des professeurs aux Pays-Bas. Cette formation est de plus en plus tournée vers l'école et s'oriente davantage dans une direction qui privilégie la compétence. Dans une première partie, nous constatons qu'aux Pays-Bas les instituts de formation des enseignants prennent des initiatives pour développer des programmes et des contrôles basés sur les compétences. Pour l'instant cependant, les fondements de cette évolution restent encore assez fragiles. Deuxièmement, on se rend compte que les écoles développent et mettent en place des projets d'amélioration de la profession d'enseignant, mais ceux qui forment les étudiants collaborent rarement à ces projets. Troisièmement, les formateurs d'enseignants dans les écoles ne peuvent pas encore satisfaire au niveau professionnel que l'on veut atteindre. Les formateurs des enseignants dans les instituts de formation pour enseignants ont aussi besoin de temps et de soutien pour s'adapter àla nouvelle situation. Pourtant, il y a des progrès et l'on va dans la bonne direction. En este artículo describimos cómo la escasez de profesores está acelerando en Holanda un proceso en el que la formación de profesores se basa cada vez más en las competencias y en el que hay una mayor participación de las escuelas. Abordamos tres temas. En primer lugar, constatamos que los centros de formación de profesores en Holanda están tomando iniciativas para elaborar evaluaciones y currículos basados en las competencias. Sin embargo, hasta ahora estas iniciativas no han tenido una base sólida. En segundo lugar, está claro que las escuelas, por su parte, están elaborando y ejecutando planes para mejorar el nivel de los profesores, pero que los profesores en formación rara vez forman parte de esos planes. En tercer lugar, los formadores de profesores en las escuelas no pueden cumplir aún las normas profesionales y los formadores de profesores en los centros de formación también necesitan tiempo y apoyo para adaptarse a las nuevas circunstancias. Sin embargo, existen signos prometedores de mejoramiento de estos aspectos. In diesem Artikel beschreiben wir, dass der Lehrermangel die Entwicklung einer Ausbildung von niederländischen Lehrern in eine mehr kompetenz- und schulbezogene Richtung beschleunigt. Wir beschäftigen uns mit drei Themen: Erstens sehen wir, dass die Lehrerausbildungsinstitute der Niederlande Initiativen zur Entwicklung von kompetenzbezogenen Curricula und zur Erfolgsbewertung ergreifen. Bis jetzt haben diese Entwicklungen allerdings ein schwaches Fundament. Zweitens ist klar, dass Schulen Professionalisierungspläne entwickeln und ausführen. Die Praktikanten sind jedoch selten in diese Pläne einbezogen. Drittens können die Lehrerausbilder in Schulen den akademischen Normen noch nicht Genüge leisten. Lehrerausbilder in Lehrerausbildungsinstitute brauchen auch Zeit und Unterstützung, um sich neuen Verhältnissen anzupassen. Es gibt jedoch vielversprechende Entwicklungen in die richtige Richtung.  相似文献   

Erratum to: Nudging museums attendance: a field experiment with high school teens     

Patrizia Lattarulo  Marco Mariani  Laura Razzolini 《Journal of Cultural Economics》2017,41(3):279-281

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Ayotzinapa 43: The Criminal Corruption of the Mexican State     

Marco A. Jimenez 《Educational Philosophy and Theory》2016,48(2):119-122

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It doesn’t matter,but: examining the impact of ambient learning displays on energy consumption and conservation at the workplace     

Dirk Börner  Marco Kalz  Marcus Specht 《Environmental Education Research》2015,21(6):899-915

This study reports an intervention to initiate environmental learning and facilitate pro-environmental behaviour. The purpose was to examine the impact of ambient learning displays on energy consumption and conservation at the workplace, more specifically the evaluation of learning outcome and behaviour change. Using a quasi-experimental design, the empirical study was conducted among employees working at a university campus. For the experimental treatments, ambient learning display prototypes were varied on two design dimensions, namely representational fidelity and notification level. The results do not provide clear evidence that the design of the displays influences learning outcome or that the displays lead to pro-environmental behaviour change. Nevertheless, the sole deployment of the display prototypes eased the comprehension of the information provided and lowered the need for additional information. Thus, ambient learning displays provide a promising framework in the context of environmental learning and beyond.  相似文献