Measurement of three-dimensional hand kinematics during swimming with a motion capture system: a feasibility study

Current trends in swimming biomechanics are focused on accurate measurements. Nowadays, reliable calibration methods have been proposed to reach an accuracy of about 1 mm on rigid structure. But the question remains about the final accuracy for three-dimensional hand kinematics measurement during the underwater phase of front crawl swimming. Furthermore, most research is based on manual tracking with two or more cameras. In this paper we propose a protocol to acquire three-dimensional hand kinematics when swimming in a specific pool with a motion analysis system behind windows. Results highlight the benefits of using such a system in terms of accuracy and feasibility: the time allowed for post-processing is ten times lower and the quantified improved accuracy is better than with manual tracking.     

Distinction on the box: Cultural capital and the social space of broadcasting

The literature on cultural capital has had relatively little to say about television viewing, except insofar as television has served as a negative point of reference in relation to which other cultural practices register their distinctiveness. This article, by contrast, examines the respects in which practices of distinction are operative within the space of broadcast television. Looking first at the ‘internal economy’ of television as expressed in the relations between genre, programme and channel preferences, it then examines how these preferences are related to occupational class, gender, level of education and ethnicity. While showing that divisions within the space of broadcasting are most powerfully articulated in terms of age and gender, the article also shows that occupational class and level of education play important roles in stratifying television audiences along traditional ‘high’/‘low’ lines. A closer analysis of the relations between these variables reveals more complex patterns of distinction, particularly in the place occupied by ‘new drama’ and ‘new comedy’ in the preferences of younger, well-educated viewers.     

The early assessment conundrum: Lessons from the past,implications for the future

The early childhood educational field has garnered attention with initiatives to foster skill acquisition in young children prior to kindergarten entry. These initiatives, in conjunction with the rigorous demands of curricular reform and a burgeoning accountability movement, invoke questions regarding the adequacy of the instruments used to assess young children and the inherent difficulties in conducting such assessments. Because the effectiveness of education relies critically on the sound diagnoses of children's readiness for learning and the measurement of their subsequent progression throughout the schooling process, critical issues in early assessment must be addressed. An examination of past practices was synthesized with recent research to focus awareness on the insufficient content domain, restrictive context, adverse timing and questionable psychometric properties, specifically the inappropriate norms and low predictive validity, of many instruments. Both the implications of and compensatory strategies for each issue are considered. © 2004 Wiley Periodicals, Inc. Psychol Schs 41: 737–749, 2004.     

Impact of combining data from multiple instruments on performance of patient-based real-time quality control

IntroductionIt is unclear what is the best strategy for applying patient-based real-time quality control (PBRTQC) algorithm in the presence of multiple instruments. This simulation study compared the error detection capability of applying PBRTQC algorithms for instruments individually and in combination using serum sodium as an example.Materials and methodsFour sets of random serum sodium measurements were generated with differing means and standard deviations to represent four simulated instruments. Moving median with winsorization was selected as the PBRTQC algorithm. The PBRTQC parameters (block size and control limits) were optimized and applied to the four simulated laboratory data sets individually and in combination.ResultsWhen the PBRTQC algorithm were individually optimized and applied to the data of the individual simulated instruments, it was able to detect bias several folds faster than when they were combined. Similarly, the individually applied algorithms had perfect error detection rates across different magnitudes of bias, whereas the error detection rates of the algorithm applied on the combined data missed smaller biases. The performance of the individually applied PBRTQC algorithm performed more consistently among the simulated instruments compared to when the data were combined.DiscussionWhile combining data from different instruments can increase the data stream and hence, increase the speed of error detection, it may widen the control limits and compromising the probability of error detection. The presence of multiple instruments in the data stream may dilute the effect of the error when it only affects a selected instrument.     

Dealing with ‘fragile identities’: resistance and refiguring in women mathematics students

Many learners may be successful in mathematics but nevertheless see themselves as existing only on the margins of the practice, or as lacking stability in it – in this sense, they have what can be called a fragile identity. Although this kind of relationship with mathematics is not limited to girls and women, they do appear to express such fragile identities more often or more readily. Drawing on qualitative and quantitative data from undergraduates in three English universities, this paper presents an analysis of the way in which university mathematics is differentially experienced by men and women, and of the part this may play in women’s ongoing narratives of self as mathematicians. It is suggested that some women resist traditional positionings in the mathematics world, drawing on local resources which enable a sense of agency as successful students and a refiguring of their relationships with mathematics.