A comparison of methods for determining dimensionality in Rasch measurement

This study compares the Rasch item fit approach for detecting multidimensionality in response data with principal component analysis without rotation using simulated data. The data in this study were simulated to represent varying degrees of multidimensionality and varying proportions of items representing each dimension. Because the requirement of unidimensionality is necessary to preserve the desirable measurement properties of Rasch models, useful ways of testing this requirement must be developed. The results of the analyses indicate that both the principal component approach and the Rasch item fit approach work in a variety of multidimensional data structures. However, each technique is unable to detect multidimensionality in certain combinations of the level of correlation between the two variables and the proportion of items loading on the two factors. In cases where the intention is to create a unidimensional structure, one would expect few items to load on the second factor and the correlation between the factors to be high. The Rasch item fit approach detects dimensionality more accurately in these situations.     

From Reading Readiness to Reading Competence: The Role of Self-Regulation in At-Risk Children

This study investigated how self-regulation contributes to the development of reading competence in an at-risk sample of 157 children born to adolescent mothers. It was hypothesized that reading readiness at age 5 would shape self-regulation at age 10, which in turn would influence reading competence at age 14. Based on structural equation modeling, it was concluded that self-regulation partially mediated the relationship between early reading skills and later reading competence. These findings suggest the importance of socioemotional and cognitive self-regulation in the development of reading competence; implications for classroom practice are discussed.     

The splinter in your ear: Noise as the semblance of critique

Noise appears to critique the prevailing cognitive and social habits of modernity by providing concrete and particular art objects that demand attention and jar us from one‐dimensional life. Noise sounds, for a moment, like a true alternative not only to contemporary music but to a whole way of thinking through abstract generalisation and living through commercial mediation. Understood in this way, noise makes sense. Once noise is no longer inscrutable, however, it is assimilated into popular culture and becomes a commercial novelty. The blatant contradiction of the commodification of noise gives rise to a second order of critique wherein noise parades its uselessness and occasions reflection on the tortured existence of art in modernity, the ubiquity of identity thinking, and the relation between use and exchange value. This ironic endgame for noise, however, is itself absorbed by consumer culture and noise lives on as but another cool, extreme product. The cultural reception of noise thereby demonstrates the mechanism by which modernity absorbs artistic attempts to critique it, and noise is ultimately understood as a desperate but spectacular failure.     

What determines the location choice of R&D activities by multinational firms?

We analyse 446 location decisions of R&D activities by multinational firms incorporated in the European Union over 1999–2006. Our results suggest that on average, the location probability of a representative R&D foreign affiliate increased with agglomeration economies from foreign R&D activities, human capital, proximity to centres of research excellence and the research and innovation capacity of the region. Further, our evidence suggests that in comparison to European multinational firms, the effects of patents intensity and proximity to centres of research excellence were stronger in the case of North American multinational firms. While government R&D expenditure intensity increased the probability of location of R&D activities by European multinational firms in the region, it did not have a significant effect on the probability of location of R&D activities by North American multinational firms.     

Can scapular and humeral head position predict shoulder pain in adolescent swimmers and non-swimmers?

Abstract

The aims of this study were to determine whether scapular and humeral head position can predict the development of shoulder pain in swimmers, whether those predictors were applicable to non-swimmers and the annual rate of shoulder pain in adolescent swimmers and non-swimmers. Forty-six adolescent swimmers and 43 adolescent non-swimmers were examined prospectively with a questionnaire and anthropometric measures. The questionnaire examined demographic and training variables. Anthropometric measures examined the distances between the T7 spinous process and the inferior scapula (Inferior Kibler) and T3 spinous process and the medial spine of the scapula (Superior Kibler), humeral head position in relation to the acromion using palpation, BMI and chest width. Shoulder pain was re-assessed 12 months later by questionnaire. Shoulder pain in swimmers was best predicted by a larger BMI (OR = 1.48, P = 0.049), a smaller Inferior Kibler distance in abduction (e.g. OR = 0.90, P = 0.009) and a smaller horizontal distance between the anterior humeral head and the anterior acromion (OR = 0.76, P = 0.035). These variables were not significantly predictive of shoulder pain in non-swimmers. Annual prevalence of shoulder pain was 23.9% in swimmers and 30.8% in non-swimmers (χ ² = 0.50, P = 0.478).     

A review of models of vertical,leg, and knee stiffness in adults for running,jumping or hopping tasks

Abstract

The ‘stiffness’ concept originates from Hooke's law which states that the force required to deform an object is related to a spring constant and the distance that object is deformed. Research into stiffness in the human body is undergoing unprecedented popularity; possibly because stiffness has been associated with sporting performance and some lower limb injuries. However, some inconsistencies surrounding stiffness measurement exists bringing into question the integrity of some research related to stiffness. The aim of this study was to review literature which describes how vertical, leg and knee stiffness has been measured in adult populations while running, jumping or hopping. A search of the entire MEDLINE, PubMed and SPORTDiscus databases and an iterative reference check was performed. Sixty-seven articles were retrieved; 21 measured vertical stiffness, 51 measured leg stiffness, and 22 measured knee stiffness. Thus, some studies measured several ‘types’ of stiffness. Vertical stiffness was typically the quotient of ground reaction force and centre of mass displacement. For leg stiffness it was and change in leg length, and for the knee it was the quotient of knee joint moments and change in joint angle. Sample size issues and measurement techniques were identified as limitations to current research.     

Peak power output provides the most reliable measure of performance in prolonged intermittent-sprint cycling

Abstract

The aims of this study were to determine the reliability of an intermittent-sprint cycling protocol and to determine the efficacy of one practice session on main trials. Eleven men, moderately trained team-sport athletes, completed three visits to the laboratory involving a graded-exercise test and practice session and two trials of a Cycling Intermittent-Sprint Protocol separated by three days. Data for practice and main trials were analysed using typical error of measurement, intra-class correlation and least-products regression to determine reliability. Typical error of measurement (expressed as a coefficient of variation) and intra-class correlation for peak power output from all 20 sprints for trial 1 and trial 2 were 2.9 ± 12.8% (95% confidence interval: 2.0–5.0%) and 0.96 (95% confidence interval: 0.85–0.99), respectively. Typical errors of measurement and intra-class correlation for mean power output for all 20 sprints for trials 1 and 2 were 4.2 ± 11.9% (95% confidence interval: 2.9–7.4%) and 0.90 (95% confidence interval: 0.66–0.97), respectively. The results suggest that peak power output provides a more reliable measure than mean power output. The Cycling Intermittent-Sprint Protocol provides reliable measures of intermittent-sprint performance.     

Exercise science and health-enhancing physical activity

Although technology has now infiltrated and prompted evolution in most mass participation sports, the advances in bat technology in such sports as baseball and cricket have been relatively minor. In this study, we used a simple finite element modelling approach to try to shed new light upon the underlying mechanics of the bat-ball impact, with a view to the future optimization of bat design. The analysis of a flexible bat showed that the point of impact that produced the maximum post-impact ball velocity was a function of the bat's vibrational properties and was not necessarily at the centre of percussion. The details of the analysis agreed well with traditional Hertzian impact theory, and broadly with empirical data. An inspection of the relative modal contributions to the deformations during impact also showed that the position of the node of the first flexure mode was important. In conclusion, considerable importance should be attached to the bat's vibrational properties in future design and analysis.     

Disconnects between popular discourse and home advantage research: What can fans and media tell us about the home advantage phenomenon?

Many of the factors identified as influencing the home advantage have an underlying social basis, presumably through the influence exerted by the home crowd. Beliefs in the home advantage and the causes of that advantage also have a social basis: sports coverage and fan discourse focus on some aspects of the phenomenon at the expense of others. This paper compares home advantage research with the use of the concept in media narratives and fan Internet postings. While there are many similarities across sources, the findings suggest three major differences. Fans, and to a lesser extent the media, (1) focus almost exclusively on winning as the evidence for a home advantage, (2) see crowd noise as the main factor for the home advantage, and (3) treat the phenomenon as much more transient than is suggested by academic studies. I identify several features of the phenomenon that facilitate popular views of the home advantage and suggest how future research may benefit from incorporating those views.