Activity profile of top-class association football referees in relation to performance in selected physical tests     

Javier Mallo  José-María García-Aranda  Bart Gilis  Werner Helsen 《Journal of sports sciences》2013,31(7):805-813

Abstract

The aims of the present study were (1) to analyse the physical demands of top-class referees and (2) to compare their official FIFA fitness test results with physical performance during a match. The work rate profiles of 11 international referees were assessed during 12 competitive matches at the 2003 FIFA Under-17 World Cup and then analysed using a bi-dimensional photogrammetric video analysis system based on direct lineal transformation (DLT) algorithms. In the first 15 min of matches, the referees were more active, performing more high-intensity exercise (P < 0.01) than in the first 15 min of the second half. During the second half of matches, the referees covered a shorter distance (P < 0.01), spent more time standing still (P < 0.05), and covered less ground cruising (P < 0.05), sprinting (P < 0.05), and moving backwards (P < 0.001) than in the first half. Also in the second 45 min, the distance of referees from infringements increased (P < 0.05) in the left attacking zone of the filed. There was also a decrease (P < 0.05) in performance in the period following the most high-intensity activity, compared with the mean for the 90 min. Time spent performing high-intensity activities during a match was not related to performance in the 12-min run (r ² = 0.30; P < 0.05), the 200-m sprint (r ² = 0.05; P < 0.05), or the 50-m sprint (r ² = 0.001; P < 0.05). The results of this study show that: (1) top-class referees experienced fatigue at different stages of the match, and (2) the typical field tests used by FIFA (two 50-m and 200-m sprints, followed by a 12-min run) are not correlated with match activities.  相似文献   

Linking human,technological, and relational assets to technological innovation: exploring a new approach     

Castro  Gregorio Martín-de  Delgado-Verde  Miriam  Amores-Salvadó  Javier  Navas-López  José Emilio 《知识管理研究与实践》2013,11(2):123-132

In a knowledge-based economy, firms' technological innovations represent one of the best ways in order to survive and to achieve firm success. Nonaka and Takeuchi stated that technological innovation is close to firms' intellectual or knowledge asset management, and additional efforts are needed to understand these complex causal relationships. If we can assume that technological innovation causation rarely has a single cause, and that these causes rarely operate in isolation from each other, empirical research needs a new configurational perspective, where the integrity of firms' technological innovations as complex configurations of causal factors are preserved. This way, using a configurational approach, and primary data of 251 technology-based firms based in Spain, this paper explores firms' human, technological, and relational assets configurations and product innovations.

  相似文献   

Changing attitudes and intentions related to doping: An analysis of individual differences in need for cognition     

Javier Horcajo  David Santos  Joshua J. Guyer  Lorena Moreno 《Journal of sports sciences》2013,31(24):2835-2843

ABSTRACT

Research has shown that athletes’ attitudes towards the use of banned performance-enhancing substances are reliable predictors of their intentions to use these substances, which in turn can be relevant predictors of their actual doping behaviours. Despite the important role played by attitudes and intentions in doping, research analysing how to change those attitudes and intentions is relatively scarce. The present study examined how individual differences in Need for Cognition (NC, Cacioppo & Petty, 1982) influenced doping-related attitude change and subsequent behavioural intentions. Participants were randomly assigned to read a persuasive message either against or in favour of legalising the use of several banned substances, including anabolic androgenic steroids (AAS) and Erythropoietin (EPO). In addition, participants completed the NC scale, and finally reported their attitudes and behavioural intentions regarding the legalisation proposal. As hypothesised, results showed that participants who received an anti-legalisation message had significantly more unfavourable attitudes towards the proposal than participants who received a pro-legalisation message, regardless of NC. However, as predicted, NC moderated the relationship between individuals’ attitudes and their intentions. That is, high-NC participants showed greater attitude-intention correspondence than low-NC participants.  相似文献   

Variable training: effects on velocity and accuracy in the tennis serve     

Hector Hernández-Davo  Tomás Urbán  Jose Manuel Sarabia  Casto Juan-Recio  Francisco Javier Moreno 《Journal of sports sciences》2013,31(14):1383-1388

Abstract

Variable practice has been shown to be an effective strategy to improve open motor skills. However, the usefulness of this procedure in closed motor skills remains controversial. The following study has the objective of analysing the effects of variability practice in the improvement of a closed skill. The skill studied has been the tennis serve. Thirty young tennis players (13 ± 1.52 years), divided in two groups, took part in this study. One group practiced in variable conditions and the other group in consistency conditions. Both groups performed 12 training sessions (60 serves/session). The variable practice group improved their accuracy significantly compared with the consistency group (F_3.25 = 3.078; P = 0.035). The velocity of serve increased after training in both groups (F_3.25 = 15.890; P = 0.001). The practice in variable conditions seems to be effective in improving the performance of the tennis serve.  相似文献   

List of Reviewers     

Coral Falco  Javier Molina-García  Octavio Álvarez  Isaac Estevan 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(4):381-382

The aim of this study was to investigate the effects of target distance on temporal and impact force parameters that are important performance factors in taekwondo kicks. Forty-nine taekwondo athletes (age = 24.5 ± 5.9 years; mass = 79.9 ± 10.8 kg) were recruited: 13 male experts, 21 male novices, 8 female experts, and 6 female novices. Impact force, reaction time, and execution time were computed. Three-way repeated measure ANOVAs revealed significant ‘distance’ effect on impact force, reaction time, and execution time (p = 0.001). Comparisons between distance conditions revealed that taekwondo athletes kicked with higher impact force from short distance (17.6 ± 7.5 N/kg) than from long distance (13.1 ± 5.7 N/kg) (p < 0.001), had lower reaction time from short distance (498 ± 90 ms) and normal distance (521 ± 111 ms) than from long distance (602 ± 121 ms) (p < 0.001), and had lower execution time from short distance (261 ± 69 ms/m) than from normal distance (306 ± 105 ms/m) or from long distance (350 ± 106 ms/m) (p = 0.003 and p < 0.001, respectively). In conclusion, target distance affected the kick performance; as distance increases, impact force decreased and reaction time increased. Therefore, when reaction to a simple visual stimulus is needed, kicking from a long distance is not recommended, as longer time is required to respond.  相似文献   

Two teacher quality measures and the role of context: evidence from Chile     

Maria Veronica Santelices  Edgar Valencia  Jorge Gonzalez  Sandy Taut 《Educational Assessment, Evaluation and Accountability》2017,29(2):111-146

This research examines empirically the relationship between two measures of teacher quality: one based on professional standards and a second one using teacher value-added estimates. It also studies the extent to which teacher observable characteristics, such as teacher training variables, are associated to better performance on either of these measures and whether any of these two assessments is able to effectively measure teacher quality isolated from the effect of the context where teachers work. Context in this article is defined as any variable that is not under the direct control of the teacher but plays an important role on student learning and we believe is captured by school and municipal variables. The study uses hierarchical linear models and information from national and standardized assessments from Chile, specifically from the municipal education sector. Results show a small correlation between the two measures of teacher quality, in the lower end of results from previous studies conducted in the USA, and suggest that there is only a limited relationship between both measures of teacher quality. Teacher initial education type and professional development were statistically associated only to the standard-based measure of teacher quality. Context (both the school and municipal levels) plays an important role in the teacher effect measure, and in the standard-based measures, therefore, we conclude that neither of these measures are context-free. We expect that these results will contribute to the discussion about how to best measure teacher quality and how to evaluate teacher performance both in Chile and other parts of the world.  相似文献   

High school ranks and admission tests as predictors of first year medical students' performance     

Javier Touron 《Higher Education》1987,16(3):257-266

This article focuses on the predictive values of certain academic variables, high school ranks and admission tests, as related to grades at the end of the first year of the Licenciate in Medicine in Spain. Multiple regression equations were calculated for each first year subject. Multiple R values ranged from 0.41 to 0.61 which implies explained variance percentages of 16.5 and 37.5. The best predictor was found to be the high school grade point average in science courses, the global examination and the admission test average. The importance of taking into account these variables in the admission process is considered. Also the inclusion of some aptitudinal variables is discussed. Finally the need to establish prediction performance tables to be used in the counselling process of admitted students is considered.This is based on a paper presented at the 8th Annual Meeting of the Spanish Society for Medical Education held at Zaragoza on 26–27 October 1984.  相似文献   

Development and validation of ageist myths in a psychotherapy questionnaire (AMPQ): professional ageism among psychology graduate students     

Javier López  Cristina Noriega  Montse Giner 《Educational gerontology》2020,46(10):642-652

ABSTRACT

Ageism is a problem in aging societies. Clinical psychologists and undergraduate psychology students have shown negative attitudes toward older adults. However, no speci?c measure against ageist myths in the psychotherapeutic context is available. This study aims to develop and present the psychometric properties of the Ageist Myths about Psychotherapy Questionnaire (AMPQ).

These issues were examined by surveying 222 psychology graduates at higher education institutions about their attitudes and behaviors concerning psychotherapy with older adults, negative stereotypes toward aging, and attitudes toward dementia.

Using principal components analysis, 10 items were retained and one factor was obtained with an acceptable reliability index. Signi?cant associations were found between the AMPQ and negative stereotypes toward aging, and attitudes toward dementia.

Results revealed that universities and colleges with psychology programs have an ageist bias. Implications for college formation in aging, and older adults with mental health problems, are discussed and presented.  相似文献   

EEG/ERP MEASURES OF EMOTION–COGNITION INTEGRATION DURING DEVELOPMENT     

Martha Ann Bell  Anjolii Diaz 《Monographs of the Society for Research in Child Development》2012,77(2):8-16

  相似文献   

Assessing the effects of school‐wide Second Step implementation in a predominately English language learner,low SES,Latino sample     

Jacqueline A. Brown  Shane R. Jimerson  Erin Dowdy  Victoria Gonzalez  Kaitlyn Stewart 《Psychology in the schools》2012,49(9):864-875

Because school violence is widespread, social and emotional competence must be targeted. Second Step is a social and emotional violence‐prevention curriculum that teaches prosocial skills and reduces aggressive behavior. The purpose of this study was to examine the effects of Second Step implementation on students (N = 403) in preschool through fourth grade who were predominately Latino, English language learners, and from families with low socioeconomic status. The data of 165 out of the 403 students were included in the present study. Analyses consisted of paired‐samples t‐tests to identify changes in social and emotional knowledge and behavioral and emotional risk. Results showed that there was a significant increase in both social and emotional knowledge and behavioral and emotional risk following the implementation of Second Step. These results are discussed with regard to previous and future research, limitations, and implications for school practice.  相似文献