反手击球5原则

对于大多数网球练习者而言,反手都是自己技术上的一个弱点。这项技术并不是难以攻克的壁垒,它可以通过练习成为你在球场上的杀手锏,当对手自以为得计时,一记完美的反手击球就会让他跌破眼镜。好啦,开始我们的反手击球练习吧,五项基本原则是掌握这一技术的敲门砖,一定不能忽视。     

Seasonal variation in physical activity among preschool children in a northern Canadian city

Little research has examined seasonal differences in physical activity (PA) levels among children. Proxy reports of PA were completed by 1,715 parents on their children in Edmonton, Alberta, Canada. Total PA (TPA) minutes were calculated, and each participant was classified as active, somewhat active, or inactive. Logistic regression models were conducted to examine associations between PA status and seasons. Significant seasonal differences were observed for TPA, weekday PA, weekend PA, and active play. Children were significantly more likely to be physically active in the summer and spring and somewhat physically active in the summer and fall, relative to winter Children living in cold climates are less likely to be physically active in the winter.     

The fourth dimension: A motoric perspective on the anxiety–performance relationship

This article focuses on raising concern that anxiety–performance relationship theory has insufficiently catered for motoric issues during, primarily, closed and self-paced skill execution (e.g., long jump and javelin throw). Following a review of current theory, we address the under-consideration of motoric issues by extending the three-dimensional model put forward by Cheng, Hardy, and Markland (2009) (‘Toward a three-dimensional conceptualization of performance anxiety: Rationale and initial measurement development, Psychology of Sport and Exercise, 10, 271–278). This fourth dimension, termed skill establishment, comprises the level and consistency of movement automaticity together with a performer's confidence in this specific process, as providing a degree of robustness against negative anxiety effects. To exemplify this motoric influence, we then offer insight regarding current theories’ misrepresentation that a self-focus of attention toward an already well-learned skill always leads to a negative performance effect. In doing so, we draw upon applied literature to distinguish between positive and negative self-foci and suggest that on what and how a performer directs their attention is crucial to the interaction with skill establishment and, therefore, performance. Finally, implications for skill acquisition research are provided. Accordingly, we suggest a positive potential flow from applied/translational to fundamental/theory-generating research in sport which can serve to freshen and usefully redirect investigation into this long-considered but still insufficiently understood concept.     

Examining the perceived value of professional judgement and decision-making in mountain leaders in the UK: a mixed-methods investigation

This paper utilised a two-part mixed-methodology to examine the value placed on judgement and decision-making by a sample of qualified mountain leaders in the UK. Qualified leaders (N = 331) completed a web-based survey and a smaller sample (N = 8) were then interviewed. Survey data showed that mountain leaders place greater value on their judgements and decision-making when compared to the technical skills of mountain navigation and rope work; however, the process for developing these judgement skills was unclear. Interview data identified that judgement skills appear transferrable from other domains experienced by the leaders (e.g. emergency services, military) but are then recontextualised and modified for effective use within mountain leadership. The leaders facilitated this via a nested reflective process that combines in-action, on-action and on-action/in-context aspects that rely on metacognition. This combination of reflection and metacognition allows for rapid development of judgement making skills in-context. Implications for mountain leadership training are discussed.     

Chemistry Is in the News: assessing intra‐group peer review

Interdisciplinarity is rapidly becoming a norm within both the professional and academic worlds, and the ability to collaborate is becoming an essential skill for all graduates. Chemistry Is in the News (CIITN) is a curriculum that aims to teach students this skill by engaging student collaborative groups in a project that ties real world events and topics to the content taught in the classroom. While the collaborative activity has been successful in many ways, the challenge of maintaining individual accountability within the collaborative activity has persisted. The need to balance the tension between promoting collaboration and maintaining individual performance standards drove the development of an intra‐group peer review system. In developing this peer review system, four goals guide the design: the desire to promote collaboration, to produce a differentiated score among group members reflecting the contribution each person made, to improve student perception of fairness and accuracy in the assessment process of CIITN and to avoid artificially inflating students’ grades. The system was assessed in the winter semester of 2004 in a large lecture course at a major Midwestern university via student questionnaires and the CIITN scores. Evidence is provided to suggest that the intra‐group peer review system has met its core goals.     

Undergraduate admission policies, practices, and procedures for applicants with learning disabilities.

This study examined (a) the academic and nonacademic criteria used by admission personnel to determine the eligibility of undergraduate applicants with learning disabilities, (b) agreement of criteria used by institutions of varying competitiveness, and (c) the frequency with which admission personnel conduct validity studies on these criteria. A nonrandom sample consisting of 66 state universities and colleges in the Northeast was surveyed. The results suggest that the academic and nonacademic criteria employed are similar to those employed for applicants without learning disabilities, the criteria used by different types of institutions differ significantly, and admission personnel do not conduct validity studies. Further clarification and validation of admission criteria appears warranted.     

Employment self-disclosure of postsecondary graduates with learning disabilities: rates and rationales

One hundred thirty-two graduates with learning disabilities (LD) of a large, public, competitive postsecondary institution were surveyed to determine if they had self-disclosed their LD to their current employer and to provide the reasons for choosing to self-disclose or not to self-disclose. Based on a response rate of 67.4% (n = 89), the results indicated that 86.5% of the respondents were employed full time. Although nearly 90% of the respondents stated that their LD affected their work in some way, only 30.3% self-disclosed to their employer. Of those who had not self-disclosed, the majority reported that there was no reason or need to self-disclose. However, 46.1% reported not self-disclosing due to fear of a potentially negative impact in the workplace or due to a concern for job security. Specific rationales for disclosure and information related to the use of self-reported accommodations and strategies are presented.     

Congruence between Mothers' and Fathers' Differential Treatment of Siblings: Links with Family Relations and Children's Well-Being

We studied patterns of mothers' and fathers' differential treatment of firstborn (average age 10.5 years) and secondborn (average age 8 years) school-age siblings, and we examined the links between parents' differential treatment and children's well-being and dyadic family relationships. Mothers, fathers, and both siblings in 110 families were interviewed in their homes. For each dimension of parental behavior that we assessed (i.e., differential affection and discipline) we created groups of families that reflected mothers' and fathers' levels of differential treatment (e.g., discipline the firstborn more, equal treatment, discipline the secondborn more). Although we detected substantial correspondence between the 2 parents' differential treatment, we found a sizable group of families in which parents' reports were incongruent (i.e., 1 parent reported equal and the other differential treatment). Parental patterns were linked to differences between the siblings' well-being and both sibling and parent-child relationships, with younger siblings exhibiting greater vulnerability to differential treatment. Incongruence in differential warmth was associated with marital distress.