青少年足球运动员地域流动性的调查与分析

运用问卷调查法、文献资料法对参加中国足协组织的青少年足球冬训营球员的地域流动性进行了调研。结果表明：现阶段球队招募球员受地理因素的限制越来越小；辽宁省的球员向外流动较多；不同的球员交流目的对本土球员培养的影响作用是不同的；大多数球队都很重视外籍球员在球队中的比例，过低或者过高的比例都不利于球队的发展。旨在为青少年足球人才交流的合理进行、青少年足球运动的可持续发展提供参考。     

The effect of video-feedback on the learning of the tennis service by intermediate players

Effects of video-feedback on improvement of the tennis service were investigated in subjects having at least 2 years of playing experience in tennis. The experiment was carried out in an indoor tennis hall under normal training conditions. Subjects were randomly divided into three groups: a video-feedback training (VFT) group, a traditional training (TT) group and a control group, each consisting of 22 subjects. While the subjects of the control group received no training at all, subjects in both the VFT and TT groups were trained twice weekly during 5 consecutive weeks. Each training session lasted 40 min, of which 30 min was spent on actual practice in training of the service. The remaining 10 min was spent on watching, analysing and discussing video recordings of either their own service performed during the training session (VFT group), or ground strokes and volleys of top level players (TT group). Both the VFT and TT group showed significantly greater improvements in both achievement scores and form (technique) scores than did the control group. No differences, however, could be demonstrated between the VFT and TT group, indicating that the subjects of the former group did not benefit from the video-feedback they received. While form scores correlated significantly (P less than 0.001) with the velocity of the served ball, no such relation between form scores and spatial accuracy was apparent.     

The propositional approach to associative learning as an alternative for association formation models

Dickinson (2009) agrees with two of the core claims that were made in my target article (De Houwer, 2009): Associative learning effects (often) depend on (1) the formation of propositions and (2) the operation of nonautomatic processes. Whereas I derived these claims from propositional models of learning, Dickinson (2009) argues that they are also compatible with association formation models (AFMs). He also defends the position that only AFMs can explain “nonrational responses to associative experiences.” In this comment, I question whether there is much value in continuing to cling to AFMs.     

Indicators of sailing performance in youth dinghy sailing

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.     

Building Your Licensing and Negotiation Skills Toolkit

Licensing and the negotiating of electronic resources can be a daunting task for librarians who lack the proper skill sets and are unfamiliar with the intricacies of publisher agreements. Claire Dygert broke down the individual elements of a standard licensing agreement and explained the importance of protecting the rights of libraries. By providing insight from her years of experience, librarians learned how to develop a support network, build confidence, and be more effective negotiators.