On the proper understanding of the limiting behavior of generalizations of the h- and g-indices     

Nees Jan van Eck  Ludo Waltman   《Journal of Informetrics》2009,3(4):369-370

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Indicators of sailing performance in youth dinghy sailing     

Margot Callewaert  Jan Boone  Bert Celie  Dirk De Clercq 《European Journal of Sport Science》2015,15(3):213-219

Abstract

This study aimed to determine indicators of sailing performance in 2 (age) groups of youth sailors by investigating the anthropometric, physical and motor coordination differences and factors discriminating between elite and non-elite male optimist sailors and young dynamic hikers. Anthropometric measurements from 23 optimist sailors (mean ± SD age = 12.3 ± 1.4 years) and 24 dynamic youth hikers (i.e. Laser 4.7, Laser radial and Europe sailors <18 years who have to sail the boat in a very dynamic manner, due to a high sailor to yacht weight ratio) (mean ± SD age = 16.5 ± 1.6 years) were conducted. They performed a physical fitness test battery (EUROFIT), motor coordination test battery (Körperkoordinationstest für Kinder) and the Bucket test. Both groups of sailors were divided into two subgroups (i.e. elites and non-elites) based on sailing expertise. The significant differences, taking biological maturation into account and factors discriminating between elite and non-elite optimist sailors and dynamic hikers were explored by means of multivariate analysis of covariance and discriminant analysis, respectively. The main results indicated that 100.0% of elite optimist sailors and 88.9% of elite dynamic hikers could be correctly classified by means of two motor coordination tests (i.e. side step and side jump) and Bucket test, respectively. As such, strength- and speed-oriented motor coordination and isometric knee-extension strength endurance can be identified as indicators of sailing performance in young optimist and dynamic youth sailors, respectively. Therefore, we emphasise the importance of motor coordination skill training in optimist sailors (<15 years) and maximum strength training later on (>15 years) in order to increase their isometric knee-extension strength endurance.  相似文献   

Validation of two accelerometers to determine mechanical loading of physical activities in children     

Ursina Meyer  Dominique Ernst  Silvia Schott  Claudia Riera  Jan Hattendorf  Jacqueline Romkes 《Journal of sports sciences》2015,33(16):1702-1709

The purpose of this study was to assess the validity of accelerometers using force plates (i.e., ground reaction force (GRF)) during the performance of different tasks of daily physical activity in children. Thirteen children (10.1 (range 5.4–15.7) years, 3 girls) wore two accelerometers (ActiGraph GT3X+ (ACT), GENEA (GEN)) at the hip that provide raw acceleration signals at 100 Hz. Participants completed different tasks (walking, jogging, running, landings from boxes of different height, rope skipping, dancing) on a force plate. GRF was collected for one step per trial (10 trials) for ambulatory movements and for all landings (10 trials), rope skips and dance procedures. Accelerometer outputs as peak loading (g) per activity were averaged. ANOVA, correlation analyses and Bland–Altman plots were computed to determine validity of accelerometers using GRF. There was a main effect of task with increasing acceleration values in tasks with increasing locomotion speed and landing height (P < 0.001). Data from ACT and GEN correlated with GRF (r = 0.90 and 0.89, respectively) and between each other (r = 0.98), but both accelerometers consistently overestimated GRF. The new generation of accelerometer models that allow raw signal detection are reasonably accurate to measure impact loading of bone in children, although they systematically overestimate GRF.  相似文献   

Optimal search strategies for identifying moderators and predictors of treatment effects in PubMed     

Marcia Tummers  Ralph van Hoorn  Charlotte Levering  Andrew Booth  Gert Jan van der Wilt  Wietske Kievit 《Health information and libraries journal》2019,36(4):318-340

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The unacknowledged value of female academic labour power for male research careers     

Petra Angervall  Jan Gustafsson 《高等教育研究与发展》2015,34(5):815-827

Academic work in Sweden's higher education system is changing character. Distinctly different career pathways are emerging, as facilities for developing research careers and capital have become both more restricted and more dependent on external funding. These developments are in focus in the present article. Based on ethnographic research and a series of semi-structured interviews with new academics and senior academic mentors in education faculties, the research suggests that several factors intercede in how careers are developed and experienced. The unacknowledged exploitation of female academic labour is perhaps amongst the more significant of these.  相似文献   

Contextualising ECEC research: the case of Slovenia     

Maša Vidmar 《International Journal of Early Years Education》2015,23(3):313-328

In the present study the longitudinal relations between quantity of centre-based child care (in months) and teacher reports of internalising and externalising behaviour in the first and second grades were examined for 325 Slovenian children. The socio-political context of affordable, accessible and homogenously high-quality child care is quite different compared to the context in countries from which many child-care studies originate (e.g. the USA). In Slovenia quality standards are regulated (child:staff ratio, teacher education, curriculum), the service is subsidised and children are guaranteed a place after the end of parental leave (i.e. at 11 months). In the described socio-political context a beneficial effect of child care quantity was found for internalising behaviour, while there were negative effects for externalising behaviour. Children who spent more time in child care exhibited less internalising behaviour and more externalising behaviour in the first grade of school, both with small coefficient sizes. Our study shows that even in the context of progressive child care some positive as well as less positive effects of child care participation on child development occur.  相似文献   

Endorsing achievement goals exacerbates the big-fish-little-pond effect on academic self-concept     

Sofie Wouters  Hilde Colpin  Jan Van Damme  Karine Verschueren 《教育心理学》2015,35(2):252-270

The big-fish-little-pond effect (BFLPE) model predicts students’ academic self-concept to be negatively predicted by the achievement level of their reference group, controlling for individual achievement. Despite an abundance of empirical evidence supporting the BFLPE, there have been relatively few studies searching for possible moderators. Integrating the BFLPE model with Achievement Goal Theory, the present study aims to determine whether the negative effect of class-average achievement on academic self-concept is moderated by individual and class-average achievement goals. Our sample comprised of 2987 students (50% boys) from Grade 6 in 112 elementary schools in the Flemish region of Belgium (174 classes). Applying multilevel modelling, we found a stronger BFLPE when students’ individual achievement goals were higher, regardless of the specific nature of these goals. The BFLPE was not moderated by class-average levels of achievement goals. Overall, our findings demonstrate that the BFLPE is moderated by individual goal-related factors.  相似文献   

Development of students’ conceptual thinking by means of video analysis and interactive simulations at technical universities     

Peter Hockicko  L′uboš Krišt′ák  Miroslav Němec 《European Journal of Engineering Education》2015,40(2):145-166

Video analysis, using the program Tracker (Open Source Physics), in the educational process introduces a new creative method of teaching physics and makes natural sciences more interesting for students. This way of exploring the laws of nature can amaze students because this illustrative and interactive educational software inspires them to think creatively, improves their performance and helps them in studying physics. This paper deals with increasing the key competencies in engineering by analysing real-life situation videos – physical problems – by means of video analysis and the modelling tools using the program Tracker and simulations of physical phenomena from The Physics Education Technology (PhET?) Project (VAS method of problem tasks). The statistical testing using the t-test confirmed the significance of the differences in the knowledge of the experimental and control groups, which were the result of interactive method application.  相似文献   

Comparing student and expert-based tagging of recorded lectures     

Pierre Gorissen  Jan van Bruggen  Wim Jochems 《Education and Information Technologies》2015,20(1):161-181

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Learning and Innovation in Agriculture and Rural Development: The Use of the Concepts of Boundary Work and Boundary Objects     

Talis Tisenkopfs  Ilona Kunda  Sandra šūmane  Gianluca Brunori  Laurens Klerkx  Heidrun Moschitz 《The Journal of Agricultural Education and Extension》2015,21(1):13-33

Abstract

Purpose: The paper explores the role of boundary work and boundary objects in enhancing learning and innovation processes in hybrid multi-actor networks for sustainable agriculture (LINSA).

Design/Methodology/Approach: Boundary work in LINSA is analysed on the basis of six case studies carried out in SOLINSA project under a common methodology. In developing typologies of boundary work and objects, a grounded approach is used.

Findings: LINSA analysis demonstrates the dynamic character, diverse forms and multiple functions of boundary work and objects in three domains: learning, innovation, and sustainability. Addressing specific types of goals and actors leads to specific types of boundary work and boundary objects. Context-appropriate boundary work allows aligning differing actor attitudes, gaining increased external support, and developing LINSA. The concepts of boundary work and boundary objects are relevant in a broad range of divergent LINSA settings. Boundary work has its limitations, but its facilitation supports reaching LINSA goals.

Practical Implications: The paper proposes recognising context-appropriate forms of boundary work and skilful use of emerging boundary objects to both promote internal consolidation of LINSA and effective external communication to foster learning and innovation for sustainability.

Originality/Value: The paper provides insights into the forms, dynamic and outcomes of boundary work in LINSA in three key domains: developing shared knowledge base, co-producing innovation and negotiating sustainability.  相似文献