Kinematic differences of elite and high-performance tennis players in the cross court and down the line forehand     

Johannes Landlinger  Stefan Josef Lindinger  Thomas Stöggl  Herbert Wagner  Erich Müller 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(4):280-295

This study identified and compared the full body kinematics of different skill levels in the forehand groundstroke when balls were hit cross court and down the line. Forty-three three-dimensional retro-reflective marker trajectories of six elite and seven high-performance players were recorded using an eight-camera 400 Hz, Vicon motion analysis system. The six highest horizontal velocity forehands with reliable kinematics of all participants were analysed for each specific situation (a total of 156 analysed shots). Significant differences (p < 0.01) and large effect sizes were observed between elite and high-performance players in linear velocity of the shoulder (2.0 vs. 1.2 m/s), angular velocity of the pelvis (295 vs. 168 °/s), and angular velocity of the upper trunk (453 vs. 292 °/s) at impact. The elite group showed a tendency towards higher racquet velocities at impact (p < 0.05). No significant differences were found in angular displacement of the racquet, hip alignment, or shoulder alignment at the completion of the backswing; nor did angular displacement vary significantly at impact. Irrespective of the group, different shoulder, hip, and racquet angles were found at impact, depending on the situation. The results should assist coaches when striving to improve their players' forehand.  相似文献   

Children with mathematics learning disabilities in Belgium   总被引：6，自引：0，他引：6  

Desoete A  Roeyers H  De Clercq A 《Journal of learning disabilities》2004,37(1):50-61

In Belgium, between 3% and 8% of the children in elementary schools have mathematics learning disabilities (MLD). Many of these children have less developed linguistic, procedural, and mental representation skills. Moreover, a majority of the children have been found to show inaccurate prediction and evaluation skills in Grade 3. MLD often become obvious in elementary school. Whereas some children are retained, others are referred to special education. During the last 10 years, the number of children in special education and the number of children with learning disabilities who are following a special guidance program in general education (inclusive education) have increased. Children in Belgium with MLD can get therapy for about 2 years. Nevertheless, many problems continue unresolved even in high school and adulthood.  相似文献   

Bildung in der Strukturr Sozio-ökonomischer Entwicklung: Eine Analyse von Längsschnittsdaten aus Afrika südlich der Sahara     

Herbert Bergmann 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1991,37(2):227-243

The preparation for the World Conference on Education for All at the beginning of 1990 once again showed clearly the importance of education for development in the countries of the Third World. This article explores the systemic place of education in the process of development. With the help of factor analysis it treats the following individual questions: Is education, or basic education, an independent factor? Are the many development indicators determined by general factors? Is basic education one of these factors? An analysis is made of development indicators from 1960 to 1984 drawn from World Bank reports on 38 sub-Saharan African countries. Two sets of economic, demographic and educational data have been examined: the first relates to the year 1984 (or nearest available); the second contains two years, adding an earlier set from the nearest available date to 1960. The analysis of the later set reveals five factors: general modernization, population growth, economic development, pupil-teacher ratio, and food supply to the general population. Education is not an independent factor in this list. Using the data sets from both years, seven factors are revealed. After diagonal rotation these are: basic education, degree of urbanization, pupil-teacher ratio, average standard of living attained, economic growth, service sector, food production per head, population growth, and employment in modern sectors.  相似文献   

The salish consortium for the improvement of science teaching preparation and development     

Dr. Herbert K. Brunkhorst  Robert E. Yager  Bonnie J. Brunkhorst  Martin A. Apple  David M. Andrews 《Journal of Science Teacher Education》1993,4(2):51-53

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Intervening to influence teachers'' actions and students'' involvement     

Joanne M. Herbert 《Journal of Personnel Evaluation in Education》1993,6(3):249-261

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University faculty and administrator morale: A case in Nigeria     

T. Dele Olasiji  Herbert R. Hengst 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1988,34(4):508-514

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Inverted puritanism at Brown University     

Herbert London 《Academic Questions》1991,4(2):5-6

in addition to being editor ofAcademic Questions and chairman of the National Association of Scholars  相似文献   

Correction to: ‘The negative effect of school-average ability on science self-concept in the UK,the UK countries and the world: the Big-Fish-Little-Pond-Effect for PISA 2006’     

Benjamin Nagengast  Herbert W. Marsh 《教育心理学》2012,32(4)

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Inquiry Resources Collection as a Boundary Object Supporting Meaningful Collaboration in a Wiki-Based Scientist-Teacher Community     

Hye Jeong Kim  Bruce Herbert 《Journal of Science Education and Technology》2012,21(4):504-512

Different interpretations of scientific inquiry exist between the two different communities of scientists and science teachers. Thus, in order to achieve a successful partnership between science teachers and scientists in establishing effective communities of practice, the framework for instructional practice in teacher professional development needs to be carefully designed. To respond to this challenge, we developed the Inquiry Resources Collection (IRC), which offers a wiki-based inquiry resource collection developed by scientists to support novice science teachers?? inquiry lesson design. The collaborative managing and sharing of knowledge in a professional development program via a wiki environment is the key to developing a practical resource for novice teachers teaching scientific inquiry. Based on our reflection of data gathered during 4?years of our project, we invoked the ideas of boundary objects and reflective apprenticeship between scientists and teachers to design the IRC.  相似文献   

Counseling Freshmen     

Herbert Stroup 《College Teaching》2013,61(1):27-28

Abstract

Course evaluations are used by many institutions in promotion, tenure, and merit decisions. This article discusses the influences on those evaluations and how faculty can combat those biases to ensure accurate portrayal of their teaching effectiveness. Alternative evaluation methods are reviewed, including portfolios, peer feedback sessions, and informal student surveying.  相似文献