Biomechanical loading in the triple jump

The triple jump is a demanding field event in which a jumper must tolerate extremely high impact forces while maintaining high horizontal speed. The present study was designed to clarify the mechanical loading characteristics and the role of neuromuscular function in the triple jump. Seven national triple jumpers (4 males, 3 females) volunteered to perform 3-6 jumps. The mean best performances were 14.32+/-0.45 m and 11.90+/-0.28 m for males and females, respectively. The three longest triple jumps for each jumper were selected for final analysis. The mean contact times were 0.139 s (hop), 0.157 s (step) and 0.177 s (jump). The largest ground reaction forces were observed in the step (15.2 times body weight), while the highest peak pressures were recorded under the heel and forefoot. The plantar pressure of the lateral side of the forefoot was highly related to the length of the triple jump (P < 0.05-0.01). In addition, electromyograms of both legs Suggested that mechanical loading places high demands on the neuromuscular system, as characterized by the high rate of activation in the pre-activity phase followed by high eccentric activity. Thus, the high activities of the gastrocnemius, vastus lateralis and hip extensor muscles seem to play an important role in preventing unnecessary yielding of the jumper during the braking phase.     

Swedish full text retrieval: Effectiveness of different combinations of indexing strategies with query terms

In this paper, which treats Swedish full text retrieval, the problem of morphological variation of query terms in the document database is studied. The Swedish CLEF 2003 test collection was used, and the effects of combination of indexing strategies with query terms on retrieval effectiveness were studied. Four of the seven tested combinations involved indexing strategies that used normalization, a form of conflation. All of these four combinations employed compound splitting, both during indexing and at query phase. SWETWOL, a morphological analyzer for the Swedish language, was used for normalization and compound splitting. A fifth combination used stemming, while a sixth attempted to group related terms by right hand truncation of query terms. The truncation was performed by a search expert. These six combinations were compared to each other and to a baseline combination, where no attempt was made to counteract the problem of morphological variation of query terms in the document database. Both the truncation combination, the four combinations based on normalization and the stemming combination outperformed the baseline. Truncation had the best performance. The main conclusion of the paper is that truncation, normalization and stemming enhanced retrieval effectiveness in comparison to the baseline. Further, normalization and stemming were not far below truncation.     

Maximal strength and power, muscle mass, endurance and serum hormones in weightlifters and road cyclists

Maximal strength, power, muscle cross-sectional area, maximal and submaximal cycling endurance characteristics and serum hormone concentrations of testosterone, free testosterone and cortisol were examined in three groups of men: weightlifters (n = 11), amateur road cyclists (n = 18) and age-matched controls (n = 12). Weightlifters showed 45-55% higher power values than road cyclists and controls, whereas the differences in maximal strength and muscle mass were only 15% and 20%, respectively. These differences were maintained when average power output was expressed relative to body mass or relative to muscle cross-sectional area. Road cyclists recorded 44% higher maximal workloads, whereas submaximal blood lactate concentration was 50-55% lower with increasing workload than in controls and weightlifters. In road cyclists, workloads associated with blood lactate concentrations of 2 and 4 mmol.l-1 were 50-60% higher and occurred at a higher percentage of maximal workload than in weightlifters or controls. Basal serum total testosterone and free testosterone concentrations were lower in elite amateur cyclists than in age-matched weightlifters or untrained individuals. Significant negative correlations were noted between the individual values of maximal workload, workloads at 2 and 4 mmol.l-1 and the individual values of muscle power output (r = -0.37 to -0.49), as well as the individual basal values of serum total testosterone and free testosterone (r = -0.39 to -0.41). These results indicate that the specific status of the participants with respect to training, resistance or endurance is important for the magnitude of the neuromuscular, physiological and performance differences observed between weightlifters and road cyclists. The results suggest that, in cycling, long-term endurance training may interfere more with the development of muscle power than with the development of maximal strength, probably mediated by long-term cycling-related impairment in anabolic hormonal status.     

New Modes of Internal Governance of Higher Education Institutions: The case of Göteborg University

Swedish higher education institutions havebeen given increased autonomy to organise theirinternal affairs, raising numerous demands onleadership and governance. Changes are so profoundthat institutions wanting to create an`entrepreneurial response' through a newdecision-making structure must undergo a culturerevolution, threatening existing power structures. Three organising principles are used to describe andanalyse Göteborg University. One conclusion isthat collegial decision-making bodies shouldsimultaneously be redefined, reestablished andabolished, depending on the issues dealt with.Commissions as deans and department heads must beclear and accountable to superiors or tonon-sub-optimising boards in a balanced powerstructure.     

Collaborative processes during report writing of a science learning project: The nature of discourse as a function of task requirements

The aim of this article is to specify how different aspects of task assignments are related to different types of student discourse during the report writing phase of a science learning project. A group of four ninth-grade students of the Finnish comprehensive school (about 15-year-olds) participated in a project work involving laboratory experiments, reading literature, and analysing and reporting research findings. The empirical data were collected through videotaping and interviews in authentic classroom settings. The results indicated that construction of shared, high-level understanding was quite rare in this case of small group interaction. As one of the main reasons for this, we suggest that the learning tasks were defined in a way that did not encourage shared reflection and high-level discourse. The students’ task was mostly to answer fact-seeking questions made by their teacher to guide the report writing, which promoted recollection rather than reasoning. In order to facilitate high-level discourse and learning, more attention should be paid to the kind of processes that task assignment triggers. The findings are discussed in the framework of how teachers could formulate their task assignments to promote high-level discourse.     

New Approaches to Spoken Document Retrieval

This paper presents four novel techniques for open-vocabulary spoken document retrieval: a method to detect slots that possibly contain a query feature; a method to estimate occurrence probabilities; a technique that we call collection-wide probability re-estimation and a weighting scheme which takes advantage of the fact that long query features are detected more reliably. These four techniques have been evaluated using the TREC-6 spoken document retrieval test collection to determine the improvements in retrieval effectiveness with respect to a baseline retrieval method. Results show that the retrieval effectiveness can be improved considerably despite the large number of speech recognition errors.     

Teaching strategies to improve students’ vocabulary and text comprehension

European Journal of Psychology of Education - Good readers use various comprehension strategies to understand texts. However, many students lack knowledge on how to purposefully and effectively use...     

Conceptualising and testing the relationship between actual and perceived motor performance: A cross-cultural comparison in children from Australia and Germany

ABSTRACT

Previous studies investigating the relationship between motor skill, physical activity and fitness in children have not thoroughly considered the role of self-perception. Therefore, the study aim was to test a theoretical framework, which considered both actual and perceived motor skill as well as actual and perceived fitness. Potential moderating effects of sex and country were considered. Data on motor skill, fitness, as well as self-perception of motor skill and fitness were collected from 145 Australian children and 214 German children (age range 7 to 10 years). For actual motor skill and fitness, mean differences for sex, age and country were found. For perceived motor performance (perceived motor skill and perceived fitness) no mean differences were found for age. Path analyses were performed. The final model showed significant relations between actual performance (object control skill, fitness) and perceived performance (object control skill, fitness). All model paths had low to moderate regression weights with the lowest relationship reported between actual and perceived fitness. Sex and country showed no effects. This integrated approach has led to a better understanding of the relationship between children’s perceived and objective performance, and cultural differences within them.