The effects of self-handicapping on attributions and perceived judo competence     

Greenlees I  Jones S  Holder T  Thelwell R 《Journal of sports sciences》2006,24(3):273-280

The aim of this study was to examine hypotheses derived from Jones and Berglas's (1978) self-handicapping model. It was hypothesized that individuals using many self-handicaps would use more internal attributions and report greater gains in perceived judo ability following success than individuals using few self-handicaps. In addition, it was hypothesized that individuals using many self-handicaps would use more external attributions and report less reduction in perceived judo ability following failure. Fifty-three judo players completed measures of trait self-handicapping, situational self-handicapping and a measure of perceived judo ability before competition. Following competition, the participants completed the Causal Dimension Scale II and the measure of perceived judo ability for a second time. Analyses of variance revealed that high self-handicappers attributed failure to more external factors than low self-handicappers. It was also found that high self-handicappers reported less of a reduction in perceived judo ability following failure than low self-handicappers. The findings therefore provide support for the potential short-term benefits of self-handicapping in sport, although further research is required to examine the long-term implications of using self-handicaps.  相似文献   

Mechanical behaviour of natural turf sports pitches across a season     

Matt Caple  Iain James  Mark Bartlett 《Sports Engineering》2012,15(3):129-141

A study assessing the mechanical behaviour of six natural turf pitches of varying sporting level and surface construction was undertaken over a period of 10?months, spanning a sporting season (August 2010 to May 2011). Penetration resistance and shear resistance were measured with the GoingStick^?, impact hardness and surface energy absorption were measured with the 2.25?kg Clegg Impact Soil Tester and the Dynamic Surface Tester device, respectively. The two sand rootzone pitches were more resistant to deformation and less variable in their impact behaviour (impact hardness and energy absorption) through the season than the native soil pitches containing greater proportions of silt and clay. Greater consistency was shown for penetration resistance and shear resistance on one of the sand rootzone pitches, with the other behaving similar to the native soil pitches for these parameters. The sand rootzone surfaces exhibited greater (P?<?0.05) impact hardness than the native soil pitches in the winter period of the season (November to mid-March) compared to the beginning or end periods of the season, where data were statistically similar (P?>?0.05). The greater consistency of sand rootzone surfaces should be considered for the effect it may have on player and team performance, and injury potential. Analysis of data against Performance Quality Standard benchmarks indicated that all data on the sand rootzones exceeded preferred values for impact hardness, indicating these ranges may be obsolete for the modern elite natural turf surface.  相似文献   

Changing the stability conditions in a back squat: the effect on maximum load lifted and erector spinae muscle activity     

Iain M. Fletcher  Ashley Bagley 《Sports biomechanics / International Society of Biomechanics in Sports》2014,13(4):380-390

The aim of this study was to identify how changes in the stability conditions of a back squat affect maximal loads lifted and erector spinae muscle activity. Fourteen male participants performed a Smith Machine (SM) squat, the most stable condition, a barbell back (BB) squat, and Tendo-destabilizing bar (TBB) squat, the least stable condition. A one repetition max (1-RM) was established in each squat condition, before electromyography (EMG) activity of the erector spinae was measured at 85% of 1-RM. Results indicated that the SM squat 1-RM load was significantly (p = 0.006) greater (10.9%) than the BB squat, but not greater than the TBB squat. EMG results indicated significantly greater (p < 0.05) muscle activation in the TBB condition compared to other conditions. The BB squat produced significantly greater (p = 0.036) EMG activity compared to the SM squat. A greater stability challenge applied to the torso seems to increase muscle activation. The maximum loads lifted in the most stable and unstable squats were similar. However, the lift with greater stability challenge required greatest muscle activation. The implications of this study may be important for training programmes; if coaches wish to challenge trunk stability, while their athletes lift maximal loads designed to increase strength.  相似文献   

Academic publishing riposte. Do not shoot the messenger     

Iain Stevenson 《普罗米修斯》2013,31(3):265-268

Iain Stevenson is Professor of Publishing and Director Emeritus of the Centre for Publishing at University College London. He has worked in the academic publishing area for many years and has been on the governing board of the Publishers’ Association. Current research is on the history of British publishing, on new publishing technology, and on the experiences of new authors in Britain and France.  相似文献   

Towards a Digital Spine: The Technological Methods that UK and US Publishers are Using to Tackle the Growing Challenge of E-Book Piracy     

Sarah Blankfield  Iain Stevenson 《Publishing Research Quarterly》2012,28(2):79-92

Despite electronic book (e-book) piracy being viewed by many rightsholders as the greatest contemporary challenge to the publishing industry, there is little research evaluating different anti-piracy methods, and explaining how they work. This paper explores the technological methods that United Kingdom and United States publishers, and their representative bodies, are using to tackle the growing challenge of e-book piracy. Through interviews with industry experts (including consultants, publishers and representatives) and publishing case studies, this paper brings together knowledge previously published and considered separately. The systems considered include The Publishers Association Copyright Infringement Portal, and Digital Rights Management in its various forms. Through these systems, we can reveal a lack of nuanced understanding in the motivations and methods of illegal file sharing, which have led to unsuccessful blanket solutions to a complex problem. By teasing out these problems, this paper will act as a point of reference for current anti-piracy measures, and consider the future options for an industry increasingly using the World Wide Web to distribute content.  相似文献   

The Effect of Depth Jumps and Weight Training on Leg Strength and Vertical Jump     

David Clutch  Mike Wilton  Carl McGown  G. Rex Bryce 《Research quarterly for exercise and sport》2013,84(1):5-10

Abstract

In recent years, a method of plyometrics (exercises that cause a rapid lengthening of a muscle prior to contraction) called depth jumping has become a part of the training routine of many athletes. Two experiments are described in which the effectiveness of the exercises is examined. In Experiment 1, undergraduate students in beginning weight training classes trained with three different jumping programs: (1) maximum vertical jumps, (2) 0.3 m depth jumps, and (3) 0.75 m and 1.10 m depth jumps. In addition, all groups also lifted weights. In Experiment 2, a weight training class and the volleyball team at Brigham Young University-Hawaii were divided into two groups. One group lifted weights and performed 0.75 and 1.10 m depth jumps. The other group only lifted weights. In Experiment 1, the three training programs resulted in increases in one repetition maximum (1 RM) squat strength, isometric knee extension strength, and in vertical jump; however, there were no significant differences between treatments. In Experiment 2, all groups made significant increases in vertical jump, except the group of weight lifters, who did no jumping. It was concluded that depth jumps are effective but not more effective than a regular jumping routine.  相似文献   

The changing shape characteristics associated with success in world-class sprinters     

Adam S. Watts  Iain Coleman  Alan Nevill 《Journal of sports sciences》2013,31(11):1085-1095

Abstract

The aims of this study were to identify whether relative shape and size characteristics of world-class sprinters have changed over time, and whether any anthropometric parameters characterize the most successful world-class sprinters. The results suggest that body mass index, reflecting greater muscle mass rather than greater adiposity, is an important factor associated with success in both male and female world-class sprinters over time. However, in female athletes the reciprocal ponderal index (RPI) has emerged as a more important indicator of success over several decades, with taller, more linear sprinters achieving greater success, as measured by sprint speed. In male sprinters it is only in the most recent decade that RPI has emerged as an important predictor of success. We speculate that the prominence of the RPI and an ectomophic somatotype being typical of the most successful world-class sprinters might be explained, in part, by the influence of stride length on sprint speed. In conclusion, these results suggest that coaches, selectors, and sports scientists should consider body shape when selecting potential athletes for sprint events, encouraging more linear athletes with a high RPI.  相似文献   

The Effect of Venue and Wind on the Distance of a Hammer Throw     

Iain Hunter 《Research quarterly for exercise and sport》2013,84(3):347-351

Abstract

The Reynolds' Balance Test was administered to selected groups of varsity athletes, physical education majors, and liberal arts majors. Significant differences in mean balance scores were found between all groups. The performance of the groups was, in descending order: varsity athletes, physical education majors, and liberal arts majors. It was suggested that the Reynolds' Balance Test gives promise of being a valuable addition to physical education testing programs.  相似文献   

In the dark: drug companies should be forced to publish all the results of clinical trials     

Chalmers I 《New scientist (1971)》2004,181(2437):19

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Special Educational Placement Decisions for Handicapped Children: An Initial New Zealand Study     

Keri Wilton  Ted Glynn  Ted Wotherspoon  Carolyn McGinley 《International Journal of Disability, Development & Education》1983,30(2):133-141

An examination was made of the case records and special educational placement decisions for a sample of 40 children, all of whom had been tested and/or reviewed by school psychologists during the year preceding the study and classified within one of the traditional special educational categories: intellectually handicapped, mentally backward, physically handicapped, hearing handicapped, visually handicapped, and emotionally maladjusted. It was found that very few children receiving special education were being returned to regular classes, and that factors other than the child's ability and/or learning/behavioural characteristics were strongly implicated in special educational decisions for mentally backward (mildly retarded) children, but to a lesser extent in decisions reached for children in other special educational categories. The study highlighted a difficulty likely to arise in a wide range of situations involving parents and children, where research access to case information must be balanced against parents’ rights to privacy and confidentiality of information disclosed in casework. Implications for the present results are considered, together with the need for alternative research strategies in this and related areas of enquiry.  相似文献