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Vincent Labrot Michael Schindler Pierre Guillot Annie Colin Mathieu Joanicot 《Biomicrofluidics》2009,3(1)
The overall traffic of droplets in a network of microfluidic channels is strongly influenced by the liquid properties of the moving droplets. In particular, the effective hydrodynamic resistance of individual droplets plays a key role in their global behavior. Here we propose two simple and low-cost experimental methods for measuring this parameter by analyzing the dynamics of a regular sequence of droplets injected into an “asymmetric loop” network. The choice of a droplet taking either route through the loop is influenced by the presence of previous droplets that modulate the hydrodynamic resistance of the branches they are sitting in. We propose to extract the effective resistance of a droplet from easily observable time series, namely, from the choices the droplets make at junctions and from the interdroplet distances. This becomes possible when utilizing a recently proposed theoretical model based on a number of simplifying assumptions. Here we present several sets of measurements of the hydrodynamic resistance of droplets, expressed in terms of a “resistance length.” The aim is twofold: (1) to reveal its dependence on a number of parameters, such as the viscosity, the volume of droplets, their velocity as well as the spacing between them. At the same time (2), by using a standard measurement technique, we compare the limitations of the proposed methods. As an important result of this comparison, we obtain the range of validity of the simplifying assumptions made in the theoretical model. 相似文献
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The introduction of decision-aid technology in sport, such as goal-line technology (GLT) in football, has generated minimal literature on supporters’ perspectives. This paper aims to investigate Scottish football supporters’ perceptions towards GLT. Two hundred and seventy Scottish supporters completed a questionnaire to assess their satisfaction with GLT and factors that influence their level of satisfaction. The majority of Scottish supporters trust the technology applied in football and favours its use. However, they are dissatisfied with GLT in part because GLT is considered to detract from the atmosphere resulting from contentious goals which supporters appreciate and lessen the debate around crucial decisions. Findings also showed that football supporters are against GLT viewing in the stadium and do not welcome future decision-aid technology in football. 相似文献
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Boriana Rukanova Yao-Hua Tan Micha Slegt Marcel Molenhuis Ben van Rijnsoever Jonathan Migeotte Mathieu L.M. Labare Krunoslav Plecko Bora Caglayan Gavin Shorten Otis van der Meij Suzanne Post 《Government Information Quarterly》2021,38(1):101496
eCommerce, Brexit, new safety and security concerns are only a few examples of the challenges that government organisations, in particular customs administrations, face today when controlling goods crossing borders. To deal with the enormous volumes of trade customs administrations rely more and more on information technology (IT) and risk assessment, and are starting to explore the possibilities that data analytics (DA) can offer to support their supervision tasks. Driven by customs as our empirical domain, we explore the use of DA to support the supervision role of government. Although data analytics is considered to be a technological breakthrough, there is so far only a limited understanding of how governments can translate this potential into actual value and what are barriers and trade-offs that need to be overcome to lead to value realisation. The main question that we explore in this paper is: How to identify the value of DA in a government supervision context, and what are barriers and trade-offs to be considered and overcome in order to realise this value? Building on leading models from the information system (IS) literature, and by using case studies from the customs domain, we developed the Value of Data Analytics in Government Supervision (VDAGS) framework. The framework can help managers and policy-makers to gain a better understanding of the benefits and trade-offs of using DA when developing DA strategies or when embarking on new DA projects. Future research can examine the applicability of the VDAGS framework in other domains of government supervision. 相似文献
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Mikaël Bouget Mathieu Rouveix Odile Michaux Jean-Marc Pequignot 《Journal of sports sciences》2013,31(12):1297-1302
Abstract In this study, we examined the effect of rapidly increased training volume and intensity on hormonal responses (salivary cortisol [C] and urinary dehydroepiandrosterone sulphate [DHEA-S]) and recovery-stress state perceived by 12 female cyclists. Over the 4-day experimental period, there was an average increase in training load of approximately 122% compared with that during the previous 12 days. Scores on subscales of the Recovery Stress Questionnaire for Athletes increased for the somatic component of stress (Fatigue, Emotional Stress and Social Stress; P < 0.05) and decreased the factor indicating recovery (General Well Being; P < 0.05) after the heavy training period. The training programme increased resting concentrations of salivary cortisol (P < 0.05) and decreased the DHEA-S/C ratio (P < 0.05). The increase in training load of cyclists was correlated with this hormonal ratio (r = ?0.48, P < 0.05). Changes in resting cortisol concentration as a result of heavy training stress were positively related to the change in Physical Complaints (r = 0.69, P < 0.01). Negative relationships were also found between changes in the DHEA-S/C ratio and changes in the somatic component of stress. The present results suggest that there is a dose–response relationship between increased training load, resting DHEA-S/C ratio and subjective assessment of stress and recovery, implying that this ratio could be used as an indicator of training status in female athletes. 相似文献
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Koen A. P. M. Lemmink Han C. G. Kemper Mathieu H. G. Greef Piet Rispens Martin Stevens 《Research quarterly for exercise and sport》2013,84(3):331-336
Abstract A growing concern for the establishment of a national system of education was clearly evident in France during the last decades of the eighteenth century. Physical education was afforded an important role in the educational projections of the period. Beginning with La Chalotais' Essai d'éducation nationale (1763) authors began to express more and more support for the inclusion of a comprehensive program of physical education. Gabriel Coyer's De l'éducation publique (1770), Louis Philipon de la Madelaine's Vues patriotiques sur l'education du peuple (1783) and De l'éducation des collèges (1784), and Jean Ver dier's Maison d'éducation physique et morale (1772) and Cours d'éducation à l'usage des eleves (1777) all contributed significantly to the concept that physical education must constitute an important and integral part of any comprehensive and viable plan for national education. Among the most important deliberations of the various French revolutionary assemblies between 1789 and 1795 were those dealing with education as a concern of the state. Legislators tried valiantly to establish a sound national plan for education. The educational reports and projects presented to the various revolutionary assemblies by Talleyrand, Condorcet, Lepelitier, Lakanal, Romme, and Daunou are usually considered by educational historians to be the most significant. Each of these specified that due attention must be devoted to physical education for children and youth. The proposals, the decrees and the debates which they precipitated did much to attract attention to the importance of the subject. It seems most likely that the period from 1763 to 1795 in France witnessed the establishment of a precedent in modem times for the concept of state concern and support for physical education. 相似文献
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Mathieu Gourlan Julie Boiché Monica Takito Bruno Fregeac Florence Cousson-Gélie 《Research quarterly for exercise and sport》2013,84(4):490-497
ABSTRACTPurpose: The theory of planned behavior (TPB) has been criticized for not including interactions between the variables assumed to predict behavior. This study sought to test how TPB variables interact to predict physical activity (PA) in children. Method: Four hundred thirty-eight children (Mage = 8.6 years, SD = 1.6 years) completed a TPB questionnaire and a PA questionnaire at Time 1. The PA measure was repeated 2 months later. Path analyses were performed to test the hypothesized model including interaction terms between TPB variables. Simple slopes analyses were also carried out to examine the statistically significant interaction terms. Results: Path analyses confirmed the classical hypotheses of TPB (R2 for intentions = .39, R2 for PA = .12) and also demonstrated only statistically significant Attitudes × Perceived Behavioral Control and Subjective Norms × Attitudes interactions (R2 change for intentions = .01, p = .009). Simple slopes analyses revealed that the strength of the association between perceived behavioral control and intentions was only statistically significantly higher (t = 2.18, p = .05, d = 0.34, 95% CI [0.03, 0.65]) when attitudes were high compared with when attitudes were low. The link between attitudes and intentions was only statistically significant at a low level of subjective norms but not at a high level. Conclusion: The integration of interaction effects between TPB variables did not increase for the variance of PA explained by the model. More research appears to be necessary to explore how the TPB could be augmented to better predict PA in children. 相似文献
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Rianne Pinxten Mathieu Desclée Marcel Eens 《International Journal of Science Education》2016,38(14):2303-2325
In 1963, the Nobel Prize-winning ethologist Niko Tinbergen proposed a framework for the scientific study of animal behaviour by outlining four questions that should be answered to have a complete understanding: causation, ontogeny, function and evolution. At present, Tinbergen’s framework is still considered the best way to guide animal behavioural research. Given the importance in science instruction of demonstrating how scientists work and ask questions, we investigated to what extent Tinbergen’s questions are addressed in biology textbooks in secondary education in Flanders, Belgium, and represented in upper-secondary and first-year university students’ explanations of behaviour in general and of specific animal behaviours. Our results revealed that teaching of animal behaviour mainly addresses ontogeny and causation, and that Tinbergen’s framework is not explicitly referred to. Students typically addressed only one or two questions, with the majority addressing causation or both causation and ontogeny when explaining behaviour in general, but function or causation and function when explaining specific animal behaviours. This high prevalence of function may be due to teleological thinking. Evolution was completely neglected, even in university students who had recently completed an evolution course. Our results revealed that transfer of the concepts of ontogeny and evolution was (almost) absent. We argue why Tinbergen’s framework should be an integral part of any biology curriculum. 相似文献
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Coaching has been identified as a key managerial behavior that organizations must promote to develop employees and achieve higher levels of performance. Despite this agreement and an increasing interest in coaching, there is still a paucity of studies exploring the impact of coaching on individual performance. This article presents an empirical investigation from two international field studies, one using business‐to‐business salespersons working in Latin America and the other one using business‐to‐consumer frontline employees from a service organization in Canada. Building on leader‐member exchange theory, we propose that coaching increases individual performance beyond the potential impact of sales experience and tenure. We find that coaching can explain between 2.9% and 6.2% of the variance in performance when controlling for tenure and experience. This article makes several scientific and managerial contributions, and also opens new avenues for research. 相似文献