Biomechanical aspects of new techniques in alpine skiing and ski-jumping

Abstract

There have been considerable changes in equipment design and movement patterns in the past few years both in alpine skiing and ski-jumping. These developments have been matched by methods of analysing movements in field conditions. They have yielded new insights into the skills of these specific winter sports. Analytical techniques have included electromyography, kinetic and kinematic methods and computer simulations. Our aim here is to review biomechanical research in alpine skiing and ski-jumping. We present in detail the techniques currently used in alpine skiing (carving technique) and ski-jumping (V-technique), primarily using data from the authors’ own research. Finally, we present a summary of the most important results in biomechanical research both in alpine skiing and ski-jumping. This includes an analysis of specific conditions in alpine skiing (type of turn, terrain, snow, speed, etc.) and the effects of equipment, materials and individual-specific abilities on performance, safety and joint loading in ski-jumping.     

Determination of the prevalence of anabolic steroids,stimulants, and selected drugs subject to doping controls among elite sport students using analytical chemistry

Abstract

Drug abuse by adolescents has been investigated in various surveys that reported correlations between age, gender, and activity. However, none of these studies included chemical analyses to help substantiate the statements of participants. In the present study, the urine specimens of 964 students (439 females, 525 males; mean age 22.1 years, s = 1.7), who applied to study sports sciences at university, were assessed for anabolic steroids, stimulants, and selected drugs prohibited in sports. In total, 11.2% of the urine specimens provided contained drugs covered by doping controls. The most frequently detected compound was the major metabolite of tetrahydrocannabinol (9.8%) followed by various stimulants related to amphetamine and cocaine (1.0%). Indications of anabolic steroid use were found in 0.4% of urine samples but originated from contraceptives containing norethisterone. The present study provided unambiguous data on the status quo of drug (ab)use by adolescents hoping for a career related to elite sport or sports sciences. No use of anabolic steroids was detected. However, evidence for stimulants and tetrahydrocannabinol administration was obtained, although not reported by any participant, which highlights the issue of under-reporting in surveys based solely on questionnaires.     

Threat Perception and Attitudes of Adolescents Towards Re-Introduced Wild Animals: A qualitative study of young learners from affected regions in Germany

Conservation efforts such as the restoration of European bison or the support of wolf immigration into Germany are often socio-scientifically controversial. In many cases, disputes are based on individuals’ threat perception and attitudes towards the animal involved. The herewith reported study provides qualitative insights into German adolescents’ (n?=?31, M_age?=?16.6 years) attitudes towards animal reintroduction, their threat and coping appraisal about wildlife and their knowledge of local endangered species. We found that students had rather limited knowledge of local endangered species. After Kellert's categories of animal attitudes, the adolescents showed a strong moralistic view on wildlife return. Naturalistic, ecologistic and utilitarian views were also strongly apparent. According to the Protection Motivation Theory, perceived threats could be identified as threats to animals on the one hand and threats to human interests on the other. Such threat perceptions often lead to a dilemma, which made it difficult to decide upon the priorities of wildlife protection versus protection of human interests. Coping mechanism to reduce threats to human interests as mentioned by the participants included restrictions of the animal as well as strategies that focused on responsibility by humans. Regarding coping mechanism to prevent the species’ extinction, participants showed a relatively superficial understanding. Furthermore, we found that participants from regions where wolves are currently immigrating or European bison are being reintroduced showed a more positive understanding of the respective animal. Our findings are discussed in the light of this topic's potential as an example of a real-life socio-scientific issue in classroom discussions.     

Seasonal variation in sports participation

This study explores indicators describing socio-demographics, sports participation characteristics and motives which are associated with variation in sports participation across seasons. Data were drawn from the German Socio-Economic Panel which contains detailed information on the sports behaviour of adults in Germany. Overall, two different measures of seasonal variation are developed and used as dependent variables in our regression models. The first variable measures the coefficient of (seasonal) variation in sport-related energy expenditure per week. The second variable measures whether activity drops below the threshold as defined by the World Health Organization (WHO). Results suggest that the organisational setting, the intensity and number of sports practised, and the motive for participation are strongly correlated with the variation measures used. For example, both, participation in a sports club and a commercial facility, are associated with reduced seasonal variation and a significantly higher probability of participating at a volume above the WHO threshold across all seasons. These findings give some impetus for policymaking and the planning of sports programmes as well as future research directions.     

Disparitäten der Bildungsbeteiligung und des Kompetenzerwerbs

Zusammenfassung Herkunftsbedingte Unterschiede der Bildungsbeteiligung und des Kompetenzerwerbs stellen einen Untersuchungsschwerpunkt in der Pisa-Studie dar. In der Bundesrepublik war ein besonders enger Zusammenhang zwischen Strukturmerkmalen famili?rer Lebensverh?ltnisse (sozio?konomischer Status, Bildungsniveau, Migrationstatus), Bildungsbeteiligung und Kompetenzerwerb nachweisbar. Ziel des Beitrags ist es, auf Grundlage der Daten der nationalen Erweiterung von PISA die disparit?tserzeugenden Effekte famili?rer Strukturmerkmale durch Prozessmerkmale famili?rer Lebensverh?ltnisse (kulturelle und kommunikative Praxis), institutionelle (Schulform) und psychologische Faktoren zu erkl?ren. Dies geschieht in zwei Schritten: Zun?chst wird mit Hilfe von Strukturgleichungsmodellen gezeigt, dass die Effekte von famili?ren Strukturmerkmalen überwiegend durch die kulturelle Praxis von Familien vermittelt sind. In einer sequentiellen Berechnung von Regressionsmodellen ergeben sich sodann deutliche Hinweise darauf, dass die Wirkung famili?rer Struktur- und Prozessmerkmale im Wesentlichen über individuelle F?higkeits- und Motivationsunterschiede (kognitive Grundf?higkeiten, Lesegeschwindigkeit, Leseinteresse, metakognitive Lernstrategien) transportiert werden. Die psychologischen und institutionellen Vermittlungsmechanismen tragen gemeinsam, aber auch jeweils spezifisch und damit kumulativ zu sozialen Unterschieden im Kompetenzerwerb bei.

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Summary Disparities in Educational Participation and Attainment: An Institutional and Individual Mediation Model The effect of students’ social background on their educational participation and attainment is a central focus of the PISA study. For Germany, the link between structural features of the family background (socio-economic status, level of education, migration status) and educational participation and attainment was shown to be particularly strong. Drawing on data from the German national extension of the PISA study, an explanation of these disparity effects is proposed, relying on process-based features (cultural and communicative practices), institutional factors (school type) and psychological factors. This is done in a two-step approach. First, structural equation models are used to show that most effects of family background structures are mediated by families’ cultural practices. Second, sequential analyses of regression models are run, providing strong evidence to suggest that the effects of family structures and processes are essentially transmitted through individual differences in competencies and motivation (basic cognitive abilities, reading speed, interest in reading, meta-cognitive learning strategies). Psychological and institutional mediation mechanisms contribute, jointly as well as individually, and thus cumulatively, to social differences in attainment.

     

Determinants of bone mineral density in patients on haemodialysis or peritoneal dialysis – a cross-sectional,longitudinal study

Introduction:

The aim of the study was to identify biomarkers of alteration in bone mineral density (BMD) in patients on haemodialysis (HD) and peritoneal dialysis (PD).

Materials and methods:

In a cross-sectional, longitudinal study dual-energy X-ray absorptiometry scans were performed in 146 HD-patients and 28 PD-patients. Follow-up after 14 months (mean) was conducted in 73 patients. As potential biomarkers we investigated parathyroid hormone (PTH), 25-hydroxy vitamin-D, ionised calcium, albumin, phosphate, and total alkaline phosphatases (t-ALP).

Results:

Both groups of dialysis patients had lower BMD in the femoral neck (BMD_neck) (P < 0.001) and forearm (BMD_forearm) (P < 0.001) compared to healthy controls, but comparable BMD in the lumbar spine (BMD_spine). BMD did not differ between dialysis types, but patients ever-treated with glucocorticoids had significantly lower BMD, while patients with polycystic kidney disease had higher BMD. BMD correlated with body weight, actual age, age at initiation of dialysis, duration of dialysis and levels of PTH and t-ALP. However, t-ALP only remained associated with low BMD_spine after adjusting for other factors (P = 0.001). In the follow-up study all patients had decreased BMD in all three locations, but only for the lumbar spine there was a significant association between BMD and the bone markers t-ALP (P = 0.009) and PTH (P = 0.013).

Conclusions:

Both HD and PD patients have low BMD, and increased concentrations of t-ALP is associated BMD_spine after adjustment, while PTH and t-ALP is associated with decrease in BMD_spine over time. This substantiates the use of these biomarkers in both types of dialysis patients.     

Elternvertreter mit Migrationshintergrund an allgemeinbildenden Schulen

Parents with a migration background are underrepresented among parent representatives at schools in Germany. However, increased involvement of these parents is essential for a lively democratic culture. To explore the motivations of parents with migration background regarding their school involvement, interviews with N?=?31 parent representatives with migration background were content analysed, starting deductively from a set of categories according to the theory of planned behaviour. In the analysis, the main category ??attitude?? was deductively subdivided into ??motivation in the course of action/intrinsic value??, ??results and consequences regarding own interests?? and ??results and consequences regarding others/altruistic motivation??. ??Subjective norm?? was inductively differentiated into ??other parents??, ??teachers and leadership team?? and ??other persons/perceived general expectations??; ??perceived behavioural control?? was differentiated into the subcategories ??assertiveness and freedom from anxiety??, ??language competence??, ??socioeconomic background??, ??availability of time??, ??setting in school and school district?? and ??field expertise and know-how??. Additionally, ??habit?? was deductively established and retained as a main category. Analysis of 513 statements resulted in an interrater-agreement of ???=?0.82. Implications for working with parents in an intercultural context are discussed.     

A new approach to increasing diversity in engineering at the example of women in engineering

A new initiative to incorporate diversity issues into the common engineering curriculum at the University of Wollongong (UoW) in Australia is outlined and the effect on student awareness quantified. The diversity issues were illustrated in the example of women in engineering, seeing that the numbers of women in engineering have dropped drastically over the last five years at UoW. However, the methodology applied can be adjusted to any diversity group to suit the needs of the institution performing the activity. The method is based on the hypothesis that raising awareness and understanding across the entire student body will be a first step to change. The approach is different to the traditional recruitment and marketing approach of convincing women to try engineering with little follow up support and subsequently often low retention. The initiative involves a diversity lecture delivered to all fourth year engineering students as part of a compulsory management subject. It is anticipated that with the current approach all students are made aware of the problems that women expect to face in the engineering profession. This awareness is hoped to bring about some of the required change in culture and prepare women to draw on available support. The strategy does not exclude men, but includes them as instruments for positive change through an understanding of the benefits of a gender-balanced and diverse work environment on everyone. The initiative is popular with students who through their feedback are requesting more such activities, in particular in early years of engineering education.