Is it possible to voluntarily increase hamstring muscle activation during landing from a snow jump in alpine skiing? - a pilot study

Activation of the hamstrings has been discussed as a measure for reducing strain on the ACL during jump landings in alpine skiing. The current study tested the hypothesis that hamstring and quadriceps activation can be voluntarily increased by the athlete. Specifically, two different instructions – to increase hamstring activation or to increase upper-leg co-contraction – were compared to normal landings. Eight members of the German national and junior national squad in freestyle skiing (age 19.6 ± 3.8 years; weight 66.1 ± 13.2 kg; height 172.2 ± 7.7 cm) performed 12 jump landings on a prepared run, 4 with no specific instruction, 4 with the instruction to generally activate the thigh muscles, and 4 with the instruction to specifically activate the hamstrings. Electromyographic (EMG) signals were recorded on the biceps femoris (BF), semitendinosus (ST), vastus lateralis (VL), rectus femoris (RF) and vastus medialis (VM). EMG activation levels were integrated over three landing phases and analysed with a repeated measures ANOVA. The instruction produced a significant main effect in ST (p = .026), VM (p = .032) and RF (p = .001). Contrary to previous research, the current study suggests that hamstring muscle activation levels can be voluntarily increased during jump landing, particularly in co-activation with its antagonists.     

Conditioning exercises in ski jumping: biomechanical relationship of squat jumps,imitation jumps,and hill jumps

As hill jumps are very time-consuming, ski jumping athletes often perform various imitation jumps during training. The performed jumps should be similar to hill jumps, but a direct comparison of the kinetic and kinematic parameters has not been performed yet. Therefore, this study aimed to correlate 11 common parameters during hill jumps (Oberstdorf Germany), squat jumps (wearing indoor shoes), and various imitation jumps (rolling 4°, rolling flat, static; jumping equipment or indoor shoes) on a custom-built instrumented vehicle with a catch by the coach. During the performed jumps, force and video data of the take-off of 10 athletes were measured. The imitation and squat jumps were then ranked. The main difference between the hill jumps and the imitation and squat jumps is the higher maximal force loading rate during the hill jumps. Imitation jumps performed on a rolling platform, on flat ground were the most similar to hill jumps in terms of the force–time, and leg joint kinematic properties. Thus, non-hill jumps with a technical focus should be performed from a rolling platform with a flat inrun with normal indoor shoes or jumping equipment, and high normal force loading rates should be the main focus of imitation training.     

Night Awakening and Its Association With Executive Functioning Across the First Two Years of Life

Longitudinal associations between signaled night awakening and executive functioning (EF) at 8 and 24 months in children with (≥ 3 awakenings, n = 77) and without parent-rated fragmented sleep (≤ 1 awakening, n = 69) were studied. EF was assessed with the Switch task at 8 and 24 months. At 24 months, behavioral tasks and parental ratings of EF (Behavior Rating Inventory of Executive Function–Preschool version) were also used. In the Switch task, children with fragmented sleep were less able to learn stimulus sequences and inhibit previously learned responses than children without fragmented sleep. The groups differed only marginally in parental ratings of EF, and no differences were found in behavioral EF tasks. These results suggest that eye movement-based measures may reveal associations between sleep and EF already in infancy and toddlerhood.     

Exploring doctorate holders’ perceptions of the non-academic labour market and reputational problems they relate to their employment

Doctoral employment outside universities has been increasing, as universities cannot employ all doctorate holders. Nevertheless, it has been argued that the shift from doctoral programs to the non-academic labour market has been limited. In this qualitative study, more than 800 verbal answers given by doctorate holders to a pair of open-ended questions were content-analysed to explore doctorate holders’ perceptions of the non-academic labour market and the reputational problems they relate to their employment. The study identifies four reputational problems which doctorate holders relate to their employment: the oversupply problem, the overeducation problem, the consistency problem and the communication problem. By identifying potential reputational problems on the doctorate holders level, this research contributes novel information in terms of both theory development and practitioner insights.

     

Teachers’ information processing and judgement accuracy: effects of information consistency and accountability

European Journal of Psychology of Education - Research has shown that teachers are able to adapt their processing strategy of student information to situational demands, whereby they flexibly use...     

Information Retrieval can Cope with Many Errors

The retrieval of documents that originate from digitized and OCR-converted paper documents is an important task for modern retrieval systems. The problems that OCR errors cause for the retrieval process have been subject to research for several years now. We approach the problem from a theoretical point of view and model OCR conversion as a random experiment. Our theoretical results, which are supported by experiments, show clearly that information retrieval can cope even with many errors. It is, however, important that the documents are not too short and that recognition errors are distributed appropriately among words and documents. These results disclose that an expensive manual or automatic post-processing of OCR-converted documents usually does not make sense, but that scanning and OCR must be performed in an appropriate way and with care.     

Prospective Teachers' Conceptions of the Knowledge Base for Teaching Chemistry at the German Gymnasium

Journal of Science Teacher Education -     

National Devolution in Swedish Higher Education -- A Quest for New Local Leadership. The Case of Leadership Development at Göteborg University

In 1993 a new national form for governance was introduced in Swedish higher education. The new regime, best described in terms of deregulation and decentralisation, among other things, required a new individually based leadership at universities.The paper describes the development of one particular 10-day interfaculty leadership training course for heads of departments, directors of study and other local managers, its content and methods and some implications for strategic management in higher education institutions.Four such implications are covered: constructing a new social identity as leaders, getting leadership acceptance in an individualistic academic-freedom culture, training academic leaders in accordance with professional values, and dealing with accountability in a collegial decision-making environment.