English Premiership Academy knee injuries: lessons from a 5 year study

This study addresses the epidemiology of knee injuries in adolescent males. Data were collected prospectively from 41 Premiership soccer academies over a 5 year period from July 2000 to June 2005. A total of 12,306 player seasons were registered in the U9 to the U16 age categories with a total of 1750 recordable injuries specific to the knee joint. There was a mean incidence of 0.71 (95% confidence interval ± 0.05) knee injuries per player per year, and a median of 17 (inter-quartile range 9-38) training days and 2 (inter-quartile range 1-4) matches missed per knee injury. Knee injuries were found to be most common in the 14-16 year age group. Six hundred and nine (35% of total) injuries were classed as severe resulting in more than 28 days' absence. Injuries were more likely to be sustained in a competitive or match-play environment (862 or 52%) than in training (796 or 48%), and a non-contact mechanism was implicated in 823 (55%) of recorded cases. Peaks in injury numbers were seen in early season and subsequent to the winter break. Sprain was the most common diagnosis recorded, with the medial collateral ligament affected in 23% of all knee injuries. Knee injuries are common in elite youth footballers. In this uninsured age group, it could be argued that earlier medical intervention may reduce long-term damage to the immature skeleton.     

The long-term athlete development model: physiological evidence and application

Within the UK, the "Long Term Athlete Development" (LTAD) model has been proposed by a variety of national governing bodies to offer a first step to considering the approach to talent development. The model, which is primarily a physiological perspective, presents an advancement of understanding of developing athletic potential alongside biological growth. It focuses on training to optimize performance longitudinally, and considers sensitive developmental periods known as "windows of opportunity". However, it appears that there are a number of problems with this theoretical model that are not necessarily transparent to coaches. Principally, the model is only one-dimensional, there is a lack of empirical evidence upon which the model is based, and interpretations of the model are restricted because the data on which it is based rely on questionable assumptions and erroneous methodologies. Fundamentally, this is a generic model rather than an individualized plan for athletes. It is crucial that the LTAD model is seen as a "work in progress" and the challenge, particularly for paediatric exercise scientists, is to question, test, and revise the model. It is unlikely that this can be accomplished using classical experimental research methodology but this should not deter practitioners from acquiring valid and reliable evidence.     

Effects of self-talk: a systematic review

This article presents a systematic review of the literature examining the relationship between self-talk and performance. "Second-generation questions" regarding potential mediators and moderators of the self-talk-performance relationship were also examined. A total of 47 studies were analyzed. Results indicated beneficial effects of positive, instructional, and motivational self-talk for performance. Somewhat surprisingly, two evidence-based challenges to popular current viewpoints on self-talk emerged. First, negative self-talk did not impede performance. Second, there was inconsistent evidence for the differential effects of instructional and motivational self-talk based on task characteristics. Results from the mediation-based analysis indicate that cognitive and behavioral factors had the most consistent relationships with self-talk. The findings are discussed in the context of recent theoretical advances, and the article includes recommendations for future research (e.g., the use of designs allowing the testing of meditational hypotheses) and for current applied practice (e.g., avoiding the use of thought-stopping techniques).     

Influence of casein phosphopeptide-amorphous calcium phosphate application,smear layer removal,and storage time on resin-dentin bonding

The aim of this study is to evaluate the influence of Tooth Mousse (TM) application, smear layer removal, and storage time on resin-dentin microtensile bond strength (μTBS). Dentin specimens were divided into two groups: (1) smear layer covered; (2) smear layer removed using 15% EDTA for 90 s. In each group, half the specimens were treated once with TM for 60 min. After bonding procedures using a two-step self-etching adhesive (Clearfil SE Bond (CSE); Kuraray Medical, Tokyo, Japan), an all-in-one adhesive (G-Bond (GB); GC Corp, Tokyo, Japan), and a total-etch adhesive (Adper Single Bond 2 (SB); 3M ESPE, St. Paul, MN, USA), the specimens were stored for 3 d or 6 months in deionized water at 37 °C, and μTBS was tested and analyzed. With the exception of SB (no TM application) and GB, the μTBS was significantly increased for CSE and SB using EDTA pre-conditioning and 3 d of storage (P≤0.001). Bond strength of GB decreased significantly when using EDTA (3 d storage, P<0.05). TM application only increased the μTBS of GB (no EDTA) and SB (with EDTA) after 3 d (P≤0.02). Comparing the adhesives after 3 d of storage, CSE exhibited the greatest μTBS values followed by GB and SB (P≤0.02). The factors of adhesive, EDTA, and TM did not show any significant impact on μTBS when specimens were stored for 6 months (P>0.05). The additional application of TM and EDTA for cavity preparation seems only to have a short-term effect, and no influence on μTBS of dentin bonds after a period of 6 months.     

Comparative studies of authoritarian-personality characteristics across culture, language and methods

This research was to determine whether the large differences in scores on the F scale found in previous studies (Bradburn, 1963; Kagitcibasi, 1970; Kinnis, 1977) were due to cultural differences in personality characteristics or due to differences in language and/or structure of measuring instruments.The subjects were three groups of university students from the United States and Turkey. The Turkish/English (T/E) sample attended a Turkish University where all classes were in English. The Turkish/Turkish (T/T) sample attended a Turkish University where all classes were in Turkish. The American/English (A/E) sample attended a Midwestern University.Each of the samples were administered three Scales measuring authoritarian personality characteristics. They were: Rokeach's (1960) Dogmatism scale (D scale) the standard F scale (Adorno et al., 1950) and a multiple choice format of the F scale called A scale (Neel, 1977). For the T/E and A/E subjects these scales were in English and for the T/T subjects in Turkish.For each cultural group the composite scores on each scale were obtained and used for inter-group comparisons through one-way analysis of variance (ANOVA). Within-group correlations across the three measures, the means and standard deviations of individual items and T tests were also computed. Interculture and language comparisons resulted in two significant differences on both the Dogmatism and F scales. Analysis of group, composite scales shows that these differences are due to disparities between the A/E and T/T culture/language groups. Differences across language and culture groups for the A scale were not significant. The A measure behaves differently from D and F for the two Turkish culture groups. For the A/E group, D, F, and A measures are almost undifferentiable. The results suggest the effect of measurement instruments on inter-cultural differences in inter-measure comparisons. This indicates a response format effect (agreer bias or acquiescence set).     

Accuracy and Precision

Within the framework of a two-hour interactive lecture, we explore the related ideas of accuracy and precision in calculation. The aim is to show that numerical data must be understood as numbers in a context.     

Measuring Pupil Progress at Key Stage 1: Using baseline assessment to investigate value added

This paper presents results from an LEA-commissioned value-added project conducted with 107 primary schools in Surrey. The project was designed to explore the use of baseline assessment at entry to reception classes to measure pupil progress across Key Stage 1 (KS1). Pupil performance in KS1 assessments of the core curriculum areas English (reading and writing), mathematics and science were analysed. The results of multi-level analyses, the impact of pupil background factors, the feedback of results to schools and the way Surrey Education Service and schools are using the information in school improvement activities are described.