Using COTS Search Engines and Custom Query Strategies at CLEF

This paper presents a system for bilingual information retrieval using commercial off-the-shelf search engines (COTS). Several custom query construction, expansion and translation strategies are compared. We present the experiments and the corresponding results for the CLEF 2004 event

The Who, How, Why, and What of Leadership in Secondary School Improvement: Lessons Learned in England

Although arguments in scholarly journals claim that leadership is critical in initiating and sustaining school improvement, ambiguity surrounds the sources and role of leadership. In addition, little research documents how educators involved in school improvement perceive who leads, how, why, and for what purposes leadership is important. This article reports a case study of head teachers' and teachers' perspectives of leadership in an English secondary school involved in a university-based school improvement program. Specifically, we present a summary of the research as well as interpretations and themes constructed from the data analysis. Interpretations support recent theoretical claims that schools are complex organizations requiring multiple leaders and a distributed model of leadership accomplish improvement goals; and academic writing that urges a rethinking of school improvement. In concluding we argue that the development of professional expertise is to fostering successful schooling over time and call for a consideration of emergent perspectives of leadership in addressing issues related to influence and inclusion of teachers in goal-setting and leadership in school development.Alors que l'on retrouve dans les revues académiques des arguments selon lesquels le leadership est essentiel pour initier et maintenir l'amélioration des écoles, les sources et rôle du leadership sont entourés d'ambiguïté. De plus, peu de recherche a porté sur la perception du leadership qu'ont les enseignants impliqués dans l'amélioration de l'école, sur leurs interprétations du qui, comment et pourquoi du leadership et des raisons pour lesquelles il est important. Cet article présente une étude de cas portant sur les points de vue qu 'ont des chefs d'établissement et des enseignants du leadership dans une école secondaire britannique qui participe à un programme universitaire visant l'amélioration de l'école. Plus précisément, nous présentons un résumé de la recherche ainsi que les interprétations et les thèmes qui se dégagent de l'analyse des données. Les interprétations appuient d'une part, les théories récentes selon lesquelles les écoles constituent des organisations complexes exigeant plusieurs leaders et un modèle réparti de leadership pour atteindre des buts liés à leur amélioration et d'autre part, les travaux académiques prônant que l'on repense l'amélioration des écoles. Dans notre conclusion, nous évoquons l'importance cruciale de développer une expertise professionnelle pour maintenir le succès d'une école. Nous encourageons également la considération de points de vue naissants portant sur l'influence et l'inclusion des enseignants dans l'établissement d'objectifs et dans le leadership de l'école

Editorial: Regulation of Endurance Performance: New Frontiers

Successful endurance performance requires the integration of multiple physiological and psychological systems, working together to regulate exercise intensity in a way that will reduce time taken or increase work done. The systems that ultimately limit performance of the task are hotly contested, and may depend on a variety of factors including the type of task, the environment, external influences, training status of the individual and a host of psychological constructs. These factors can be studied in isolation, or inclusively as a whole-body or integrative system. A reductionist approach has traditionally been favored, leading to a greater understanding and emphasis on muscle and cardiovascular physiology, but the role of the brain and how this integrates multiple systems is gaining momentum. However, these differing approaches may have led to false dichotomy, and now with better understanding of both fields, there is a need to bring these perspectives together

Even Between-Lap Pacing Despite High Within-Lap Variation During Mountain Biking

Purpose: Given the paucity of research on pacing strategies during competitive events, this study examined changes in dynamic high-resolution performance parameters to analyze pacing profiles during a multiple-lap mountain-bike race over variable terrain. Methods: A global-positioning-system (GPS) unit (Garmin, Edge 305, USA) recorded velocity (m/s), distance (m), elevation (m), and heart rate at 1 Hz from 6 mountain-bike riders (mean ± SD age = 27.2 ± 5.0 y, stature = 176.8 ± 8.1 cm, mass = 76.3 ± 11.7 kg, VO2max = 55.1 ± 6.0 mL · kg–1 . min–1) competing in a multilap race. Lap-by-lap (interlap) pacing was analyzed using a 1-way ANOVA for mean time and mean velocity. Velocity data were averaged every 100 m and plotted against race distance and elevation to observe the presence of intralap variation. Results: There was no significant difference in lap times (P = .99) or lap velocity (P = .65) across the 5 laps. Within each lap, a high degree of oscillation in velocity was observed, which broadly reflected changes in terrain, but high-resolution data demonstrated additional nonmonotonic variation not related to terrain. Conclusion: Participants adopted an even pace strategy across the 5 laps despite rapid adjustments in velocity during each lap. While topographical and technical variations of the course accounted for some of the variability in velocity, the additional rapid adjustments in velocity may be associated with dynamic regulation of self-paced exercise

Magnetosphere-Ionosphere Coupling Through E-region Turbulence: Anomalous Conductivities and Frictional Heating

Global magnetospheric MHD codes using ionospheric conductances based on laminar models systematically overestimate the cross-polar cap potential during storm time by up to a factor of two. At these times, strong DC electric fields penetrate to the E region and drive plasma instabilities that create turbulence. This plasma density turbulence induces non-linear currents, while associated electrostatic field fluctuations result in strong anomalous electron heating. These two effects will increase the global ionospheric conductance. Based on the theory of non-linear currents developed in the companion paper, this paper derives the correction factors describing turbulent conductivities and calculates turbulent frictional heating rates. Estimates show that during strong geomagnetic storms the inclusion of anomalous conductivity can double the total Pedersen conductance. This may help explain the overestimation of the cross-polar cap potentials by existing MHD codes. The turbulent conductivities and frictional heating presented in this paper should be included in global magnetospheric codes developed for predictive modeling of space weather.Comment: 13 pages, 5 figures, 2nd of two companion paper

Magnetosphere-Ionosphere Coupling Through E-region Turbulence 1: Energy Budget

During periods of intense geomagnetic activity, strong electric fields and currents penetrate from the magnetosphere into high-latitude ionosphere where they dissipate energy, form electrojets, and excite plasma instabilities in the E-region ionosphere. These instabilities give rise to plasma turbulence which induces non-linear currents and strong anomalous electron heating (AEH) as observed by radars. These two effects can increase the global ionospheric conductances. This paper analyzes the energy budget in the electrojet, while the companion paper applies this analysis to develop a model of anomalous conductivity and frictional heating useful in large-scale simulations and models of the geospace environment. Employing first principles, this paper proves for the general case an earlier conjecture that the source of energy for plasma turbulence and anomalous heating equals the work by external field on the non-linear current. Using a two-fluid model of an arbitrarily magnetized plasma and the quasilinear approximation, this paper describes the energy conversion process, calculates the partial sources of anomalous heating, and reconciles the apparent contradiction between the inherently 2-D non-linear current and the 3-D nature of AEH.Comment: 13 pages, 1 figure; 1st of two companion paper

Risk perception influences athletic pacing strategy.

PURPOSE: The objective of this study is to examine risk taking and risk perception associations with perceived exertion, pacing, and performance in athletes. METHODS: Two experiments were conducted in which risk perception was assessed using the domain-specific risk taking (DOSPERT) scale in 20 novice cyclists (experiment 1) and 32 experienced ultramarathon runners (experiment 2). In experiment 1, participants predicted their pace and then performed a 5-km maximum effort cycling time trial on a calibrated Kingcycle mounted bicycle. Split times and perceived exertion were recorded every kilometer. In experiment 2, each participant predicted their split times before running a 100-km ultramarathon. Split times and perceived exertion were recorded at seven checkpoints. In both experiments, higher and lower risk perception groups were created using median split of DOSPERT scores. RESULTS: In experiment 1, pace during the first kilometer was faster among lower risk perceivers compared with higher risk perceivers (t(18) = 2.0, P = 0.03) and faster among higher risk takers compared with lower risk takers (t(18) = 2.2, P = 0.02). Actual pace was slower than predicted pace during the first kilometer in both the higher risk perceivers (t(9) = -4.2, P = 0.001) and lower risk perceivers (t(9) = -1.8, P = 0.049). In experiment 2, pace during the first 36 km was faster among lower risk perceivers compared with higher risk perceivers (t(16) = 2.0, P = 0.03). Irrespective of risk perception group, actual pace was slower than predicted pace during the first 18 km (t(16) = 8.9, P < 0.001) and from 18 to 36 km (t(16) = 4.0, P < 0.001). In both experiments, there was no difference in performance between higher and lower risk perception groups. CONCLUSIONS: Initial pace is associated with an individual's perception of risk, with low perceptions of risk being associated with a faster starting pace. Large differences between predicted and actual pace suggest that the performance template lacks accuracy, perhaps indicating greater reliance on momentary pacing decisions rather than preplanned strategy.This is the author accepted manuscript. The final version is available from Wolters Kluwer via http://dx.doi.org/10.1249/MSS.000000000000050

An Analysis of Variability in Power Output During Indoor and Outdoor Cycling Time-Trials

PURPOSE::Regulation of power output during cycling encompasses the integration of internal and external demands to maximise performance. However, relatively little is known about variation in power output in response to the external demands of outdoor cycling. We compared mean power output and the magnitude of power output variability and structure during a 20-min time-trial performed indoors and outdoors.METHODS::Twenty male competitive cyclists (V̇O2peak 60.4 ± 7.1 mL·kg-1·min-1) performed two randomised maximal 20-min time-trial tests i) outdoors at a cycle-specific racing circuit or ii) indoors on a laboratory-based electromagnetically braked training ergometer, 7 days apart. Power output was sampled at 1 Hz and collected on the same bike equipped with a portable power meter in both tests.RESULTS::Twenty-min time-trial performance indoor (280 ± 44 W) was not different from outdoor (284 ± 41 W) (P = 0.256), showing a strong correlation (r = 0.94; P < 0.001). Within-person SD was greater outdoors (69 ± 21 W) compared to indoors (33 ± 10 W) (P < 0.001). Increased variability was observed across all frequencies in data from outdoor cycling compared to indoors (P < 0.001) except for the very slowest frequency bin (<0.0033 Hz, P = 0.930).CONCLUSIONS::Our findings indicate a greater magnitude of variability in power output during cycling outdoors. This suggests that constraints imposed by the external environment lead to moderate and high frequency fluctuations in power output. Therefore, indoor testing protocols should be designed to reflect the external demands of cycling outdoors