Timescales for exploratory tactical behaviour in football small-sided games

The aim of this study was to identify the dynamics of tactical behaviour emerging on different timescales in football small-sided games and to quantify short- and long-term exploratory behaviour according to the number of opponents. Two teams of four professional male footballers played small-sided games against two different teams with a variable number of opponents (3, 5 and 7). Data were collected using a combination of systematic observation and a non-differential global positioning system (15 Hz). The temporal diversity and structural flexibility of the players were determined by calculating the dynamic overlap order parameter q, entropy and trapping strength. Analysis of the exploratory dynamics revealed two different timescales, forming a different metastable landscape of action for each constraint. Fast dynamics lasted on average a few seconds and consisted of changes in tactical patterns. The long timescale corresponded to the shared tasks of offence and defence lasting tens of seconds. The players’ tactical diversity decreased with an increasing number of opponents, especially in defence. Manipulating numerical imbalance is likely to promote changes in the diversity, unpredictability and flexibility of tactical solutions. The fact that the temporally nested structure of constraints shaped the emergence of tactical behaviour provides a new rationale for practice task design. The manipulation of numerical imbalance on the timescale of a few tens of seconds, on which the exploratory behaviour of players saturates, may help coaches to optimise the exploratory efficiency of the small-sided games.     

Validation of the Microsoft Kinect® camera system for measurement of lower extremity jump landing and squatting kinematics

Cost effective, quantifiable assessment of lower extremity movement represents potential improvement over standard tools for evaluation of injury risk. Ten healthy participants completed three trials of a drop jump, overhead squat, and single leg squat task. Peak hip and knee kinematics were assessed using an 8 camera BTS Smart 7000DX motion analysis system and the Microsoft Kinect® camera system. The agreement and consistency between both uncorrected and correct Kinect kinematic variables and the BTS camera system were assessed using interclass correlations coefficients. Peak sagittal plane kinematics measured using the Microsoft Kinect® camera system explained a significant amount of variance [Range_hip = 43.5–62.8%; Range_knee = 67.5–89.6%] in peak kinematics measured using the BTS camera system. Across tasks, peak knee flexion angle and peak hip flexion were found to be consistent and in agreement when the Microsoft Kinect® camera system was directly compared to the BTS camera system but these values were improved following application of a corrective factor. The Microsoft Kinect® may not be an appropriate surrogate for traditional motion analysis technology, but it may have potential applications as a real-time feedback tool in pathological or high injury risk populations.     

Alterations in autonomic cardiac modulation in response to normobaric hypoxia

Purpose: The present study aimed to determine if autonomic cardiac modulation was influenced by acute exposure to normobaric hypoxia. Method: Ten healthy male lowland dwellers completed five block-randomised single-blinded, crossed-over acute exposures to a normobaric hypoxic environment, each separated by 24 hours’ recovery (20.3%, 17.4%, 14.5%, 12.0% and 9.8% F_IO₂). Supine recordings were made of arterial oxygen saturation and electrocardiogram (ECG). RR intervals from the ECG trace were analysed for time (SDNN, lnrMSSD), frequency (lnVLF, lnLF, lnHF, lnTP, LFnu, and HFnu), and nonlinear (DFA-α1 and SampEn) heart rate variability components. Results: A significant reduction in arterial SaO₂ occurred with reduced F_IO₂, along with a rise in heart rate (Cohen’s d?=?1.16, 95% Confidence Interval [2.64–6.46]), significant at 9.8% F_IO₂. A decrease in autonomic cardiac modulation was also found as shown by a statistically significant (at 9.8% F_IO₂) decrease in lnTP (d?=?1.84 [1.74–1.94]), and SampEn (d?=?0.98 [0.83–1.12]) and an increase in DFA-α₁ (d?=?0.72 [0.60–0.84]) from normoxia at 9.8% F_IO₂. Conclusion: The decrease in variability indicated a reduction in autonomic cardiac modulation. There appears to be a threshold ～9.8% F_IO₂ (～6000?m equiv.), below which significant alterations in autonomic control occur.     

Comparison of three web-scale discovery services for health sciences research

Objective

The purpose of this study was to investigate the relative effectiveness of three web-scale discovery (WSD) tools in answering health sciences search queries.

Methods

Simple keyword searches, based on topics from six health sciences disciplines, were run at multiple real-world implementations of EBSCO Discovery Service (EDS), Ex Libris''s Primo, and ProQuest''s Summon. Each WSD tool was evaluated in its ability to retrieve relevant results and in its coverage of MEDLINE content.

Results

All WSD tools returned between 50%–60% relevant results. Primo returned a higher number of duplicate results than the other 2 WSD products. Summon results were more relevant when search terms were automatically mapped to controlled vocabulary. EDS indexed the largest number of MEDLINE citations, followed closely by Summon. Additionally, keyword searches in all 3 WSD tools retrieved relevant material that was not found with precision (Medical Subject Headings) searches in MEDLINE.

Conclusions

None of the 3 WSD products studied was overwhelmingly more effective in returning relevant results. While difficult to place the figure of 50%–60% relevance in context, it implies a strong likelihood that the average user would be able to find satisfactory sources on the first page of search results using a rudimentary keyword search. The discovery of additional relevant material beyond that retrieved from MEDLINE indicates WSD tools'' value as a supplement to traditional resources for health sciences researchers.     

Gender differences in the academic career

This study examines sources of satisfaction, indicators of stress, academic performance, and reward structure in the academic careers of male and female faculty at a major midwestern state university. Faculty pairs were selected from five academic divisions. A total of 58 matched pairs were identified. Of these, 63 faculty responded, yielding data for 23 matched pairs. Subjects were mailed the Academic Career Development Survey, consisting of 144 items. Results indicated that self-reported physical and mental health, and professional and personal life satisfaction were high for both males and females. Both males and females placed high importance on their career and on marriage/other intimate relationships; however, both reported high levels of dissatisfaction with these factors. Gender differences were found in both satisfaction and type of stress reported; no gender differences were found in composite teaching and research performance indices. Salary data, obtained for 42 matched pairs, indicated similar salary levels for men and women. Results were discussed with respect to prior research on gender differences and the academic career.     

Design of technology-based information-referenced grouping systems for use in large urban schools

There are many subtle but extremely important differences between grouping students and tracking students for purposes of designing appropriate instructional interventions. Unfortunately, in many inner-city urban settings, the policy of grouping students eventually becomes a policy ofde facto tracking of students. While grouping students seems to be an educationally justifiable policy in many school situations, tracking students raises serious concerns with regard to its educational value, social desirability, and complicity with the legal notions of due process and equal protection. This study examines the use of a specific form ofshort-term grouping of students that is based on an information-referenced criterion for selection. Using a large sample of ninth- and eleventh-grade students, an information-referenced grouping procedure was designed for the areas of language arts and mathematics. The study finds that grouping selections, using an information-referenced criterion, are strongly associated with teachers perceptions of these students' actual educational and information needs. In addition, the information-referenced grouping design provides important specific educational feedback to both students and teachers to help low-attaining students move to mainstream classes. Finally, many of the due process concerns raised by educational researchers with regard to abuses and shortcomings of presently used ability or standardized test-driven grouping efforts are addressed.     

A comparison of the dimensions used by Iranian and American students in rating instruction

This study investigated the dimensions of teacher behavior and classroom characteristics used by Iranian high school students (N=880) in evaluating their classroom experience. Secondly, it compared these dimensions to those used by American high school students (N=599). During January, 1978, both groups of students completed the Classroom Behavior Survey (CBS). Principal components analysis with varimax rotation yielded a 12 factor solution for Iranian data and 14 for the American data. Comparison of the factors suggest that the dimensions on which Iranian and American students evaluate their teachers are substantially different, though the dimensions they use to evaluate characteristics of the course and content are similar.

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Zusammenfassung Diese Studie untersucht die Dimensionen von Lehrerverhalten und Unterrichtsweisen, die iranische Studenten zur Evaluation ihrer Klassenerfahrungen angewandt haben. Ferner vergleicht sie diese Dimensionen mit den von amerikanischen Sekundarschülern benutzten. Beide Schülergruppen beendeten ihre Untersuchungen über Unterrichtsverhalten im Januar 1978. Eine Analyse der Hauptkomponenten, mit Varimax Rotation, ergab eine 12-Faktorenlösung für die iranischen Daten gegenüber 14 Faktoren für die amerikanischen. Ein Vergleich dieser Faktoren deutet darauf hin, daß die Dimensionen, aufgrund derer die iranischen und amerikanischen Schüler ihre Lehrer bewerten, stark voneinander abweichen, während sich die für die Beurteilung der Kurse und Inhalte gebrauchten gleichen.

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Résumé Cette étude porte sur les cotes du comportement de l'enseignant et des caractéristiques de la classe utilisées par les élèves iraniens de l'enseignement secondaire. (N=880) dans leur évaluation de leur expérience scolaire. Elle compare ensuite ces cotes à celles utilisées par les élèves américains du secondaire. Les deux groupes d'élèves ont terminé leur enquête sur le comportement de la classe (CBS ECC) en janvier 1978. L'analyse des principales composantes avec rotation varimax a donné une solution à 12 facteurs pour les données iraniennes et à 14 facteurs pour les données américaines. La comparaison des facteurs suggère que les cotes selon lesquelles les élèves iraniens et américains évaluent leurs enseignants sont notablement différentes, bien que celles qu'ils utilisent pour évaluer les caractéristiques du cours et de son contenu soient similaires.

     

Teacher Efficacy Research 1998–2009: Signs of Progress or Unfulfilled Promise?

This review investigates the state of teacher self- and collective efficacy research conducted from 1998 to 2009. Two hundred and eighteen empirical articles published in 1998–2009 were examined for key characteristics and compared to research published in the previous 12 years (i.e., 1986–1997). Results from the review show increases in overall teacher efficacy research, methodological diversity, domain specificity, internationalization, and focus on collective efficacy. Continuing problem areas were a lack of attention to the sources of teacher efficacy, continued measurement and conceptual problems, a lack of evidence for the links between teacher efficacy and student outcomes, and uncertain relevance of teacher efficacy research to educational practice. An outline of directions for future teacher efficacy research is provided.     

A Study of Teacher Candidates’ Experiences Investigating Global Climate Change Within an Elementary Science Methods Course

We investigated the inclusion of a curricular module on global climate change in an Elementary Science Methods course. Using complementary research methods, we analyzed findings from 63 teacher candidates’ drawings, questionnaires, and journal entries collected throughout their participation in the module. We highlighted three focal cases to illustrate the diversity of participants’ experiences. Findings suggest potential positive impacts on teacher candidates’ content understanding related to global climate change, confidence to teach, and awareness of resources to support their future science instruction. Recommendations for science teacher education underscore the importance of providing opportunities for teacher candidates to increase their relevant content understanding, helping teacher candidates become familiar with appropriate curricular resources, and engaging in ongoing conversation and evaluation of developing views and understandings related to global climate change.