A coaches’ perspective on the contribution of anthropometry,physical performance,and motor coordination in racquet sports     

Kamasha Robertson  Johan Pion  Mireille Mostaert  Mohd Rozilee Wazir Norjali Wazir  Tamara Kramer  Irene Renate Faber 《Journal of sports sciences》2018,36(23):2706-2715

ABSTRACT

Differences and similarities between table tennis and other racquet sports exist, but are not well documented in the literature, in spite of the relevance for talent identification. In this study we aimed at identifying the key characteristics of table tennis in comparison with tennis and badminton based upon a survey in coaches. A total of 177 licensed coaches from all across the world and with diverse professional backgrounds completed a survey on anthropometric measures, physical performance, and motor coordination skills. On a scale from 1 to 10, coaches indicated to what extent a talent characteristic was important for their sport. MANOVA identified key differences as well as similarities between all three racquet sports and a subsequent discriminant analysis allocated coaches correctly for table tennis, tennis, and badminton 81.01%, 55.6%, and 71.4% respectively. Our results show that table tennis and other racquet sport coaches are well aware of differences between the racquet sports and also the importance and value of testing and assortment of skill components. These findings can assist coaches in future talent orientation and transfer in racquet sports.  相似文献   

Effect of a randomised 12-week resistance training programme on muscular strength,cross-sectional area and muscle quality in women having undergone Roux-en-Y gastric bypass     

Paul Daniels  Timothy A. Brusseau  Morgan S. Hall  Lance Davidson  Ted D. Adams 《Journal of sports sciences》2018,36(5):529-535

The purpose of this study was to examine the effect of a 12-week resistance training programme on fat-free mass (FFM), muscle cross-sectional area, muscular strength and muscle quality in women who underwent Roux-en-Y gastric bypass surgery. Participants were 16 women (mean age = 44.9 ± 10.2 years) from bariatric surgical groups who were randomly assigned into either a control or an intervention group. Air displacement plethysmography measured FFM and magnetic resonance imaging measured quadriceps muscle cross-sectional area and whole thigh muscle cross-sectional area. Muscular strength and quality was assessed using an estimated 1-Repetition Maximum assessment. All measurements were collected twice, at baseline and at a 12-week follow-up. There were significantly greater improvements in leg press strength (mean differences = 55.4%, P < 0.001, Cohen’s d = 2.4), leg extension strength (mean differences = 18.0%, P = 0.014, Cohen’s d = 0.86) and leg press muscle quality (mean differences = 54.5%, P < 0.001, Cohen’s d = 1.9) in the intervention group compared to the control group following the resistance training programme. The resistance training intervention significantly improved muscular strength and quality; however, it did not illicit changes in FFM or muscle cross-sectional area in women who underwent Roux-en-Y gastric bypass surgery.  相似文献   

Parents’ perceptions of parent–teacher relationship practices in Dutch primary schools – an exploratory pilot study     

Hélène Leenders  Carla Haelermans  Johan de Jong  Mélanie Monfrance 《Teachers and Teaching》2018,24(6):719-743

This paper shows how parents’ perceptions of parent–teacher relationship practices differ between different types of schools with respect to children’s special needs and the socio-economic status of these children. Using a questionnaire, we compare parents’ views from two special education schools, two at-risk schools serving low SES-children, and two mainstream primary education schools in the southern part of the Netherlands. The theoretical framework is based on Epstein’s Model of Parental Involvement. The results illustrate that parents and teachers in special education and at-risk schools are very much accustomed to ‘two-way communication’, in contrast to mainstream schools, and that this is valued highly by these parents. Furthermore, teachers in special and at-risk schools are more familiar with interacting with parents, involve them more in decision-making and more often co-ordinate homework practice with parents.  相似文献   

Efficient sample preparation in immuno-matrix-assisted laser desorption/ionization mass spectrometry using acoustic trapping     

Bj?rn Hammarstr?m  Hong Yan  Johan Nilsson  Simon Ekstr?m 《Biomicrofluidics》2013,7(2)

Acoustic trapping of minute bead amounts against fluid flow allows for easy automation of multiple assay steps, using a convenient aspirate/dispense format. Here, a method based on acoustic trapping that allows sample preparation for immuno-matrix-assisted laser desorption/ionization mass spectrometry using only half a million 2.8 μm antibody covered beads is presented. The acoustic trapping is done in 200 × 2000 μm² glass capillaries and provides highly efficient binding and washing conditions, as shown by complete removal of detergents and sample processing times of 5-10 min. The versatility of the method is demonstrated using an antibody against Angiotensin I (Ang I), a peptide hormone involved in hypotension. Using this model system, the acoustic trapping was efficient in enriching Angiotensin at 400 pM spiked in plasma samples.  相似文献   

Interpretation and application of the offside law by expert assistant referees: Perception of spatial positions in complex dynamic events on and off the field     

Bart Gilis  Peter Catteeuw  Evelien Van Roie  Johan Wagemans 《Journal of sports sciences》2013,31(6):551-563

Abstract

Baldo et al. (2002 Baldo, M. V. C., Ranvaud, R. D. and Morya, E. 2002. Flag errors in soccer games: The flash-lag effect brought to real life. Perception, 31: 1205–1210. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) and Helsen et al. (2006 Helsen, W., Gilis, B. and Weston, M. 2006. Errors in judging “offside” in association football: Test of the optical error versus the perceptual flash-lag hypothesis. Journal of Sports Sciences, 24: 521–528. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) considered the flash-lag effect to explain errors made by assistant referees when judging offside in association football. The main aims of the present study were as follows: (1) to determine whether the flash-lag effect emerges in offside situations on the field of play or off the field when presented as computer animations or as video footage of real-life matches; (2) to examine offside decision-making errors in two standards of assistant referee – international FIFA and Belgian national referees. The results support the flash-lag hypothesis in several ways. First, both the FIFA and Belgian assistant referees were more likely to make errors by raising their flag when they had to assess offside situations on the field of play and when presented as three-a-side computer animations. Second, more flag errors were made when the defender moved in the opposite direction to that of the attacker. Third, the strategy of raising the flag in case of doubt was not observed when an interpretation of the offside law had to be made about the involvement of play of an attacker. Future research is needed to examine the extent to which on- and off-the-field training sessions can be used as training tools to improve offside decision-making.  相似文献   

Offside decision making of assistant referees in the English Premier League: Impact of physical and perceptual-cognitive factors on match performance     

Peter Catteeuw  Bart Gilis  Johan Wagemans 《Journal of sports sciences》2013,31(5):471-481

Abstract

In the present study, we investigated the accuracy of offside judgements of assistant referees in the English Premier League. The moment in the match, the position and movement speed of the assistant referee, attacker and second-last defender, together with the angle of view for the assistant referee were all considered to underlie incorrect decisions. The error rate was 17.5% (868 of 4960 situations). As the English assistant referees tended not to signal in doubtful situations (c = 0.91), there was an overall bias towards non-flag errors (773 non-flag errors vs. 95 flag errors). The flash-lag hypothesis could explain all flag errors, whereas the optical-error hypothesis could explain a proportion of the non-flag errors (45.4%). Fatigue, movement speed, and angle of view did not have a detrimental effect on offside decision making. In conclusion, there were fewer flag errors than in the 2002 and 2006 FIFA World Cups, whereas the number of non-flag errors rose. The increased awareness of factors involved in offside decision making and the instructions to give the benefit of the doubt to attackers could have contributed to this situation.  相似文献   

Reliability and validity of the Yo-Yo intermittent recovery test level 1 in young soccer players     

Dieter Deprez  Aaron James Coutts  Matthieu Lenoir  Job Fransen  Johan Pion  Renaat Philippaerts 《Journal of sports sciences》2013,31(10):903-910

Abstract

The present study investigated the test-retest reliability from the Yo-Yo IR1 (distance and heart rate responses), and the ability of the Yo-Yo IR1 to differentiate between elite and non-elite youth soccer players. A total of 228 youth soccer players (11–17 years) participated: 78 non-elite players to examine the test-retest reliability within 1 week, added with 150 elite players to investigate the construct validity. The main finding was that the distance covered was adequately reproducible in the youngest age groups (U13 and U15) and highly reproducible in the oldest age group (U17). Also, the physiological responses were highly reproducible in all age groups. Moreover, the Yo-Yo IR1 test had a high-discriminative ability to distinguish between elite and non-elite young soccer players. Furthermore, age-related standards for the Yo-Yo IR1 established for elite and non-elite groups in this study may be used for comparison of other young soccer players.  相似文献   

Innovating strategically in information and knowledge management: Applications of organizational behavior theory     

Tor J. Larsen  Johan Olaisen 《International Journal of Information Management》2013

A business school declares its strategy as becoming a leading European institution. As main vehicle for achieving recognition is the implementation of a top-down strategy naming five academic fields as key – (a) finance, (b) economics, (c) marketing, (d) law, accounting, and auditing, and (e) organizational behavior (OB). Top management allocates resources for research, academic activities, and positions to these five strategically chosen areas. Academic areas that are not strategically named must generate their own income through educational programs and research grants. Can OB serve as the platform to ensure the survival of IS/KMS? In our analysis, we found no other business school formulating a strategy along these lines; dominating strategic themes are internationalization, research excellence, and student environment. No academic field is singled out as strategic. We argue that selecting a few academic areas as a strategy is dysfunctional. We also found that OB is not very actively employed in research, be it positioning, theory, research model, analysis, or discussion. Hence, we do not find that OB offers any theorizing help to IS/KMS – this in contrast to innovation and change theories, for which we propose an framework as a means of defining IS/KMS research projects.  相似文献   

Gaze‐Contingent Display Changes as New Window on Analytical and Holistic Face Perception in Children With Autism Spectrum Disorder          下载免费PDF全文

Kris Evers  Goedele Van Belle  Jean Steyaert  Ilse Noens  Johan Wagemans 《Child development》2018,89(2):430-445

The strength of holistic face perception in children with autism spectrum disorder (ASD) was evaluated by applying the gaze‐contingent mask and window technique to a face matching and discrimination task in 6‐ to 14‐year‐old children with (n = 36) and without ASD (n = 47), and by examining fixation patterns. Behavioral results suggested a slower and less efficient face processing in the ASD sample compared with the matched control group. Comparing the moving mask and window conditions revealed a reduced holistic face processing bias in the younger age group but not in the older sample. Preferential viewing patterns revealed both similarities and differences between both participant groups.  相似文献   

Transfer of facilitation in the rat     

T. L. Davidson  Robert A. Rescorla 《Learning & behavior》1986,14(4):380-386

In two experiments, rats solved two concurrent discrimination problems in which one stimulus (i.e., a facilitator) signaled the reinforcement of another stimulus (i.e., a target). Then a transfer test assessed the capacity of facilitators trained in one problem to promote responding to targets trained in the other. Experiment 1 found that a facilitator promoted as much responding to such a transfer target as to the target with which it was originally trained. Transfer was not obtained with a pseudofacilitator that was uninformative, in training, about the reinforcement of its target. Experiment 2 manipulated the stimulus modality of the targets and facilitators. Its results indicated that transfer performance was not due to generalization between training and transfer targets or facilitators. These results parallel those from comparable autoshaping paradigms with pigeons, and they agree with the view that facilitators promote responding by lowering the threshold for activation of the US representation.  相似文献