Professional knowledge affects action-related skills: The development of preservice physics teachers' explaining skills during a field experience

Professional knowledge is an important source of science teachers' actions in the classroom (e.g., personal professional content knowledge [pedagogical content knowledge, PCK] is the source of enacted PCK in the refined consensus model [RCM] for PCK). However, the evidence for this claim is ambiguous at best. This study applied a cross-lagged panel design to examine the relationship between professional knowledge and actions in one particular instructional situation: explaining physics. Pre- and post a field experience (one semester), 47 preservice physics teachers from four different universities were tested for their content knowledge (CK), PCK, pedagogical knowledge (PK), and action-related skills in explaining physics. The study showed that joint professional knowledge (the weighted sum of CK, PCK, and PK scores) at the beginning of the field experience impacted the development of explaining skills during the field experience (β = .38**). We interpret this as a particular relationship between professional knowledge and science teachers' action-related skills (enacted PCK): professional knowledge is necessary for the development of explaining skills. That is evidence that personal PCK affects enacted PCK. In addition, field experiences are often supposed to bridge the theory-practice gap by transforming professional knowledge into instructional practice. Our results suggest that for field experiences to be effective, preservice teachers should start with profound professional knowledge.     

Sources of identity and community among highly identified football fans in Germany. An empirical categorisation of differentiation processes1

‘Differentiation’ is identified as a key category, and an empirical system of differentiation is developed. The key category is divided into two subcategories, which are further dimensionalized. The analysis finds that highly identified fans differentiate themselves from other fans (both from their own club and from rival clubs) and strive for positive distinction. Violent acts as extreme forms of differentiation are identity-establishing for some of these fans. Confrontations with rival fans are actively sought to extend team competitions concerning the best support into a physical and violent plane and to enforce territorial claims.     

Sex differences in injury rates in team-sport athletes: A systematic review and meta-regression analysis

Background:Team-sport players have a particularly high injury risk.Although female sex is considered a risk factor,it is still unknown whether female and male team-sport players,in fact,differ in their injury rates.We aimed to compare injury rates between female and male players by systematically reviewing and meta-analyzing injury surveillance studies of both sexes in order to evaluate sex-specific differences in team-sport injuries.Methods:Studies that prospectively collected injury data for high-level female and male players(age≥16 years)in basketball,field hockey,football(soccer),handball,rugby(union and sevens),and volleyball were included.Two reviewers(AZ and ALR)independently assessed study quality and extracted data for overall,match,training,and severe injuries(>28 days’time loss)as well as data regarding injury locations and types.Incidence rate ratios(IRRs)were pooled in a meta-analysis,and meta-regression analysis was performed when 10 or more studies were available.Results:Of 20 studies,9 studies reported injury data from football,3 studies from rugby,3 studies from handball,1 study from basketball,1 study from field hockey,2 studies from volleyball,and 1 study from basketball and field hockey.For overall injuries,the pooled IRR=0.86(95%confidence interval(95%CI):0.76-0.98)indicated significantly more injuries in male than in female players.For injury location,the pooled IRR showed higher injury rates in male athletes than in female athletes for upper extremity,hip/groin,thigh,ande foot injuries.Female players had a significantly higher rate of anterior cruciate ligament injuries(IRR=2.15,95%CI:1.27-3.62)than male players.No significant sex-specific differences in IRR were found for match,training,severe injuries,concussions,or ankle sprains.Conclusion:Our meta-analysis provides evidence for sex-specific differences in the injury rates in team sports.Further epidemiological studies including both sexes in sports other than football are needed in order to strengthen the evidence.     

Predictive models reduce talent development costs in female gymnastics

This retrospective study focuses on the comparison of different predictive models based on the results of a talent identification test battery for female gymnasts. We studied to what extent these models have the potential to optimise selection procedures, and at the same time reduce talent development costs in female artistic gymnastics. The dropout rate of 243 female elite gymnasts was investigated, 5 years past talent selection, using linear (discriminant analysis) and non-linear predictive models (Kohonen feature maps and multilayer perceptron). The coaches classified 51.9% of the participants correct. Discriminant analysis improved the correct classification to 71.6% while the non-linear technique of Kohonen feature maps reached 73.7% correctness. Application of the multilayer perceptron even classified 79.8% of the gymnasts correctly. The combination of different predictive models for talent selection can avoid deselection of high-potential female gymnasts. The selection procedure based upon the different statistical analyses results in decrease of 33.3% of cost because the pool of selected athletes can be reduced to 92 instead of 138 gymnasts (as selected by the coaches). Reduction of the costs allows the limited resources to be fully invested in the high-potential athletes.     

Initial psychometric testing of the coach-adapted version of the empowering and disempowering motivational climate questionnaire: A Bayesian approach

ABSTRACT

The present study examined the psychometric properties of the coach-adapted version of the Empowering and Disempowering Motivational Climate Questionnaire (EDMCQ) using Bayesian structural equation modelling (BSEM). The sample included 780 (M_age = 36.4; SD = 10.8; males n = 698; females n = 54; 28 participants did not report sex) youth sport coaches representing five European countries (i.e., England, France, Greece, Norway, and Spain). The results did not support a 34-item five-factor, hierarchical, a two-factor BSEM, or a bifactor BSEM model across the participating countries. However, the results supported a reduced 19-item first-order, two-factor BSEM model that largely showed approximate metric invariance, but not approximate scalar invariance across the five countries. The pool of items constituting empowering and disempowering motivational climates should be refined to further enhance the empirical operationalisation of the coach-adapted version of the EDMCQ. Advancing the quality of translation-back-translation procedures across cultures and conducting multi-national pilot testing seems warranted as well. These recommendations may help to identify the distinctive aspects of each underlying sub-dimension of the EDMCQ, where coaches are the respondents, and pave the way for further examination of the proposed hierarchical multidimensional factor structure and the cross-cultural equivalence of the EDMCQ for this population.     

The only constant is change: analysing and understanding change in sport and exercise psychology research

The ability to examine within-person change is essential to test process-based theories in sport and exercise psychology. Longitudinal data, whether experimental or observational, are prerequisites to be able to examine change processes, but most longitudinal studies in sport and exercise psychology focus solely on between-person/group differences, not on within-person change. In this review, we (1) provide researchers in the sport and exercise psychology field with a framework for longitudinal research that focuses on within-person change; (2) provide an overview of how researchers in sport and exercise psychology currently analyse longitudinal data, which showed that most longitudinal studies focus on between-person/group differences; and (3) provide examples of statistical models for analysing longitudinal data that correspond to the framework for longitudinal research. In the examples, we focus on latent variable modelling, such as latent growth-curve modelling and latent change-score modelling, which capture within-person change. We argue that there is a need for stronger emphasis on the match among theory of change, temporal design, and statistical models when designing longitudinal studies in sport and exercise psychology.     

What is the future of electrical impedance spectroscopy in flow cytometry?

More than 20 years ago, electrical impedance spectroscopy (EIS) was proposed as a potential characterization method for flow cytometry. As the setup is comparably simple and the method is label-free, EIS has attracted considerable interest from the research community as a potential alternative to standard optical methods, such as fluorescence-activated cell sorting (FACS). However, until today, FACS remains by and large the laboratory standard with highly developed capabilities and broad use in research and clinical settings. Nevertheless, can EIS still provide a complement or alternative to FACS in specific applications? In this Perspective, we will give an overview of the current state of the art of EIS in terms of technologies and capabilities. We will then describe recent advances in EIS-based flow cytometry, compare the performance to that of FACS methods, and discuss potential prospects of EIS in flow cytometry.     

School-based prevention: effects on obesity and physical performance after 4 years

Juvenile obesity is increasing worldwide. Preventive strategies are warranted. The school-based Children's Health Interventional Trial (the CHILT Project) combines health education and physical activity for children. The effect on obesity and physical performance was studied after four years in 12 primary schools compared with five control schools. Anthropometric data were recorded. Physical performance was measured by a coordination test for children (balancing backwards, one-legged obstacle jumping, lateral jumping, sideways movements) and a 6-min run (endurance). No difference in the prevalence and incidence of overweight and obesity was found between the intervention and control schools before and after the intervention. Remission of overweight was higher in the intervention schools (23.2 vs. 19.2%), but not significant. An increase in coordination related to lateral jumping and balancing backwards was apparent in the intervention schools (30.6, s = 10.8 vs. 26.1, s = 10.8, P = 0.005; 21.8, s = 11.8 vs. 19.4, s = 11.7, P = 0.007), and the increase in endurance performance tended to be higher in intervention schools (100.8, s = 122.7 vs. 92.8, s = 126.0, P = 0.055), adjusted for age, sex, baseline test result, and body mass index at final examination. Therefore, preventive intervention in primary school offers the possibility to improve physical performance in children. The prevalence and incidence of obesity were not affected.