Biomechanical analysis of the penalty-corner drag-flick of elite male and female hockey players     

Cristina López De Subijana  Daniel Juárez  Javier Mallo  Enrique Navarro 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(2):72-78

The aim of this study was to analyse the kinematic sequencing in the penalty-corner drag-flicks of elite male and female field hockey players of international calibre. Thirteen participants (one skilled male drag-flicker and six male and six female elite players) participated in the study. An optoelectronic motion analysis system was used to capture the drag-flicks with six cameras, sampling at 250 Hz. Select ground reaction force parameters were obtained from a force platform which registered the last support of the front foot. Twenty trials were captured from each subject. Both player groups showed significantly (p < 0.05) smaller ball velocity at release, peak angular velocity of the pelvis, and negative and positive peak angular velocities of the stick than the skilled subject. Normalised ground reaction forces of the gender groups were also smaller than that of the skilled drag-flicker. By comparing these players we established that the cues of the skill level are a wide stance, a whipping action (rapid back lift) of the stick followed by an explosive sequential movement of the pelvis, upper trunk and stick.  相似文献   

The Ibero American Network for Research on School Effectiveness and School Improvement: A Way to Increase Educational Quality and Equity     

F. Javier Murillo  M Lourdes Hernández Rincón 《School Effectiveness & School Improvement》2013,24(1):123-132

Education systems in Latin America are demanding an improvement in their present levels of quality and equity. In order to achieve higher levels in these fields, decision-taking is necessary in all educational areas, and the theoretical–practical movements of school effectiveness and school improvement (SE and SI) can help in this task. Nevertheless, current research is neither sufficient nor satisfactory, as it is deeply ethnocentric. At the beginning of the year 2000, the Ibero American Network for Research on School Effectiveness and School Improvement (RIEME) was created with the aim of promoting research and communication on these research fields. Among its activities, the following can be mentioned: to promote international research on SE and SI; to develop and maintain a closed e-list and a web page; to organise meetings, training and advise activities, and so forth. RIEME works as a Network of networks, and is widespread in Spain, Portugal and most countries in Latin America.  相似文献   

Assessment of prosocial–altruistic behavior of members and non-members of the scout movement     

Rosario Ruiz-Olivares  M. José Pino  Javier Herruzo 《European Journal of Psychology of Education - EJPE》2013,28(2):189-199

The aim of this study is to evaluate the differences in prosocial altruistic behavior between children and young students who belong to the scout movement and those who do not belong to this or any other similar movement. The prosocial altruistic behavior has been assessed with questionnaires for the school: self-evaluation, teacher, classmate, and parents. By means of a prospective design of case–control, every scout has been compared with another non-scout matched in variables like age; number of siblings; whether he/she is the oldest, the youngest, etc.; sex; the order between the siblings; if the mother works inside or outside the home; and if he/she lives with his/her two parents. The results show that significant differences exist between one group and another in the questionnaires of self-evaluation, for the teacher and for the classmate. It seems that children and young people who are scout members are better assessed than the non-scouts in prosocial altruistic behavior.  相似文献   

Mediation role of cardiorespiratory fitness on the association between fatness and cardiometabolic risk in European adolescents: The HELENA study     

Carlos Cristi-Montero  Javier Courel-Ibez  Francisco B. Ortega  Jose Castro-Piero  Alba Santaliestra-Pasias  Angela Polito  Jrmy Vanhelst  Ascensin Marcos  Luis M. Moreno  Jonatan R. Ruiz  HELENA study group 《运动与健康科学(英文)》2021,10(3):360

PurposeThis study was aimed to analyze the mediation role of cardiorespiratory fitness (CRF) on the association between fatness and cardiometabolic risk scores (CMRs) in European adolescents.MethodsA cross-sectional study was conducted in adolescents (n = 525; 46% boys; 14.1 ± 1.1 years old, mean ± SD) from 10 European cities involved in the Healthy Lifestyle in Europe by Nutrition in Adolescence study. CRF was measured by means of the shuttle run test, while fatness measures included body mass index (BMI), waist to height ratio, and fat mass index estimated from skinfold thicknesses. A clustered CMRs was computed by summing the standardized values of homeostasis model assessment, systolic blood pressure, triglycerides, total cholesterol/high-density lipoprotein cholesterol ratio, and leptin.ResultsLinear regression models indicated that CRF acted as an important and partial mediator in the association between fatness and CMRs in 12–17-year-old adolescents (for BMI: coefficients of the indirect role β = 0.058 (95% confidence interval (95%CI): 0.023–0.101), Sobel test z = 3.11 (10.0% mediation); for waist to height ratio: β = 4.279 (95%CI: 2.242–7.059), z =3.86 (11.5% mediation); and for fat mass index: β = 0.060 (95%CI: 0.020–0.106), z = 2.85 (9.4% mediation); all p < 0.01).ConclusionIn adolescents, the association between fatness and CMRs could be partially decreased with improvements to fitness levels; therefore, CRF contribution both in the clinical field and public health could be important to consider and promote in adolescents independently of their fatness levels.  相似文献   

Assessment of health sciences and science and technology librarian e-science educational needs to develop an e-science web portal for librarians     

Andrew Creamer  Myrna Morales  Javier Crespo  Donna Kafel  Elaine Russo Martin 《Journal of the Medical Library Association》2011,99(2):153-156

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

Mallo J  Navarro E  García-Aranda JM  Gilis B  Helsen W 《Journal of sports sciences》2007,25(7):805-813

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   

The comparison of normalization procedures based on different classification systems     

Yunrong Li  Javier Ruiz-Castillo 《Journal of Informetrics》2013,7(4):945-958

In this paper, we develop a novel methodology within the IDCP measuring framework for comparing normalization procedures based on different classification systems of articles into scientific disciplines. Firstly, we discuss the properties of two rankings, based on a graphical and a numerical approach, for the comparison of any pair of normalization procedures using a single classification system for evaluation purposes. Secondly, when the normalization procedures are based on two different classification systems, we introduce two new rankings following the graphical and the numerical approaches. Each ranking is based on a double test that assesses the two normalization procedures in terms of the two classification systems on which they depend. Thirdly, we also compare the two normalization procedures using a third, independent classification system for evaluation purposes. In the empirical part of the paper we use: (i) a classification system consisting of 219 sub-fields identified with the Web of Science subject-categories; an aggregate classification system consisting of 19 broad fields, as well as a systematic and a random assignment of articles to sub-fields with the aim of maximizing or minimizing differences across sub-fields; (ii) four normalization procedures that use the field or sub-field mean citations of the above four classification systems as normalization factors; and (iii) a large dataset, indexed by Thomson Reuters, in which 4.4 million articles published in 1998–2003 with a five-year citation window are assigned to sub-fields using a fractional approach. The substantive results concerning the comparison of the four normalization procedures indicate that the methodology can be useful in practice.  相似文献   

Erratum: Green intellectual capital and environmental product innovation: the mediating role of green social capital     

Miriam Delgado-Verde  Javier Amores-Salvadó  Gregorio Martín-de Castro  José Emilio Navas-López 《知识管理研究与实践》2014,12(3):350-350

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When a robot is social: spatial arrangements and multimodal semiotic engagement in the practice of social robotics     

Alac M  Movellan J  Tanaka F 《Social studies of science》2011,41(6):893-926

Social roboticists design their robots to function as social agents in interaction with humans and other robots. Although we do not deny that the robot's design features are crucial for attaining this aim, we point to the relevance of spatial organization and coordination between the robot and the humans who interact with it. We recover these interactions through an observational study of a social robotics laboratory and examine them by applying a multimodal interactional analysis to two moments of robotics practice. We describe the vital role of roboticists and of the group of preverbal infants, who are involved in a robot's design activity, and we argue that the robot's social character is intrinsically related to the subtleties of human interactional moves in laboratories of social robotics. This human involvement in the robot's social agency is not simply controlled by individual will. Instead, the human-machine couplings are demanded by the situational dynamics in which the robot is lodged.  相似文献   

Relevance-based language modelling for recommender systems     

Javier Parapar  Alejandro Bellogín  Pablo Castells  Álvaro Barreiro 《Information processing & management》2013

Relevance-Based Language Models, commonly known as Relevance Models, are successful approaches to explicitly introduce the concept of relevance in the statistical Language Modelling framework of Information Retrieval. These models achieve state-of-the-art retrieval performance in the pseudo relevance feedback task. On the other hand, the field of recommender systems is a fertile research area where users are provided with personalised recommendations in several applications. In this paper, we propose an adaptation of the Relevance Modelling framework to effectively suggest recommendations to a user. We also propose a probabilistic clustering technique to perform the neighbour selection process as a way to achieve a better approximation of the set of relevant items in the pseudo relevance feedback process. These techniques, although well known in the Information Retrieval field, have not been applied yet to recommender systems, and, as the empirical evaluation results show, both proposals outperform individually several baseline methods. Furthermore, by combining both approaches even larger effectiveness improvements are achieved.  相似文献