Is a single question of the Global Physical Activity Questionnaire (GPAQ) valid for measuring sedentary behaviour in the Chilean population?     

Nicolas Aguilar-Farias  Jaime Leppe Zamora 《Journal of sports sciences》2017,35(16):1652-1657

A study was conducted to assess the validity of the Global Physical Activity Questionnaire (GPAQ) for measuring sedentary behaviour (SB) in the Chilean adult population. About 217 adults (93/124 male/female, 43.8 ± 15.75 years) who were randomly selected during National Health Survey 2009–2010 completed the protocol. The participants wore an ActiGraph GT3X (AG) for 7 consecutive days and then completed the GPAQ (single-item question for measuring time spent sitting in a usual day). Validity was examined using Spearman’s correlation, mean bias and limits of agreement (LoA), with AG (vertical axis <100 counts · min^?1) as the reference standard for estimates of SB in bouts of 1 (AG1), 5 (AG5) and 10 (AG10) min. Agreement between the GPAQ and AG for classifying data into quartiles and tertiles was assessed with kappa method. The GPAQ showed fair correlation with AG1, AG5 and AG10 (range = 0.23–0.26), with large mean biases (range = ?293.9, ?76.12 min · day^?1). Agreement between the GPAQ and AG1, AG5 and AG10 was poor for categorising time spent in SB into tertiles and quartiles. The single question from the GPAQ has shown fair validity for measuring SB and poor ability for correctly classifying individuals into tertiles or quartiles of SB in a Chilean population.  相似文献   

Do karate fighters use situational probability information to improve decision-making performance during on-mat tasks?     

Nicolas Milazzo  Damian Farrow  Alexis Ruffault  Jean F. Fournier 《Journal of sports sciences》2016,34(16):1547-1556

This study examined the contribution of situational probability information to the perceptual and cognitive processes underlying decision-making behaviour during in situ Karate performance. Experts and novices were required to make decisions about various attacks in different fight scenarios. The order in which the fight situations were presented was modified in order to provide advanced probability information and identify whether fighters were able to use the latter information to make better decisions. Specifically, one of the attacks was repeated every four actions. Results revealed that experts were more accurate and faster than their less skilled counterparts to block and counterattack the opponent. The experts picked up the occurrence of the attack pattern after the fifth repetition whereas novices did not. This enabled experts to improve decision time and decision accuracy. Findings suggest that such superiority could stem from the perceptual and cognitive skills possessed by the experts, thus giving them the opportunity to recognise a situation more easily. This was reinforced by gaze behaviour which demonstrated that experts used a more efficient search strategy involving fewer fixations of longer duration on a lesser number of areas relative to the novices. Moreover, experts generated more refined karate-specific knowledge structures compared with the novices.  相似文献   

Processus de preuve et situations de validation   总被引：2，自引：0，他引：2  

Nicolas Balacheff 《Educational Studies in Mathematics》1987,18(2):147-176

Résumé Nous étudions les relations entre preuves et contradictions dans la résolution d'un probleme de mathématiques. Cette étude montre la nécessité d'une approche à la fois situationnelle et cognitive, notamment en référence au fonctionnement des connaissances dans l'apprentissage des mathématiques. Ceci nous conduit à distinguer différents stades dans l'évolution des preuves pragmatiques aux preuves intellectuelles. Enfin nous montrons que le dépassement d'une contradiction ne constitue pas nécessairement un progrés cognitif, en particulier nous examinons le traitement d'un contre-exemple par des élèves de quatrième.

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Proving processes and situations for validation

A study is made of the relationship between Proofs and Contradictions in mathematics problem-solving. With respect to mathematics learning, we show the necessity for an approach being both situational and cognitive. This study leads to the demarcation of several stages from Pragmatic Proofs to Intellectual Proofs. We then go on to show that overcoming a contradiction does not necessarily constitute cognitive progress. In particular we examine how pupils (13–14 year old) cope with counterexamples.

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Editorial     

John Forge  Nicolas Rasmussen 《Metascience》2001,10(1):1-1

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Cultural Differences in Garnering Social Capital on Facebook: French People Prefer Close Ties and Americans Prefer Distant Ties     

Genavee Brown  Nicolas Michinov 《Journal of Intercultural Communication Research》2017,46(6):579-593

The link between social capital (SC) and Facebook has been widely studied in the U.S., and less is known about how students from different cultures use the site to garner SC. We measured network composition, communication on Facebook, and SC via questionnaires in France and the U.S. We found that American students have a greater proportion of distant to close ties in their networks and higher levels of bridging SC than French, the latter preferring bonding SC. A stronger relationship between SC and communication via Facebook was observed in the U.S. These findings are explained by cultural differences in relatedness.  相似文献   

A scale-based approach to interdisciplinary research and expertise in sports     

Jorge Ibáñez-Gijón  Martinus Buekers  Antoine Morice  Guillaume Rao  Nicolas Mascret  Jérome Laurin 《Journal of sports sciences》2017,35(3):290-301

After more than 20 years since the introduction of ecological and dynamical approaches in sports research, their promising opportunity for interdisciplinary research has not been fulfilled yet. The complexity of the research process and the theoretical and empirical difficulties associated with an integrated ecological-dynamical approach have been the major factors hindering the generalisation of interdisciplinary projects in sports sciences. To facilitate this generalisation, we integrate the major concepts from the ecological and dynamical approaches to study behaviour as a multi-scale process. Our integration gravitates around the distinction between functional (ecological) and execution (organic) scales, and their reciprocal intra- and inter-scale constraints. We propose an (epistemological) scale-based definition of constraints that accounts for the concept of synergies as emergent coordinative structures. To illustrate how we can operationalise the notion of multi-scale synergies we use an interdisciplinary model of locomotor pointing. To conclude, we show the value of this approach for interdisciplinary research in sport sciences, as we discuss two examples of task-specific dimensionality reduction techniques in the context of an ongoing project that aims to unveil the determinants of expertise in basketball free throw shooting. These techniques provide relevant empirical evidence to help bootstrap the challenging modelling efforts required in sport sciences.  相似文献   

Influence of a stressing constraint on stiffness and damping functions of a ski simulator's platform motion     

Deschamps T  Nourrit D  Caillou N  Delignières D 《Journal of sports sciences》2004,22(9):867-874

The aim of this study was to assess the effect of stress on a previously acquired motor coordination. Following a longitudinal learning experiment, four participants performed oscillations on a ski simulator, either in normal or stressful conditions. The results showed that the amplitude of the oscillations decreased under stress, but no significant effect was seen regarding coordination, suggesting the strong resistance to stress of overlearned behaviour. Nevertheless, for one participant, a transient regression towards a former stage of learning was observed. This result was consistent with the regression hypothesis formulated by Fuchs (1962).  相似文献   

Investigating the relationship between transactive memory and performance in collaborative learning     

Nicolas Michinov  Estelle Michinov 《Learning and Instruction》2009,19(1):43-54

The aim of the present study was to investigate the relationships between the three dimensions of transactive memory (coordination, credibility, and specialization) and performance of collaborating students. A total of 113 students, distributed into groups of two or three, participated in the study. They were required to complete a series of learning tasks during the semester and to write a joint report for each task to be evaluated by their instructors. Afterwards, they were asked to fill out a questionnaire including self-report measures of transactive memory. The results showed a well-established positive relationship between transactive memory and performance based essentially on coordination; also, performance improved linearly as members developed specializations within groups. Implications for future research in collaborative learning are discussed.  相似文献   

Rethinking Postcolonial Worlds through Physical Activities     

Stanislas Frenkiel  Nicolas Bancel 《国际体育史杂志》2015,32(7):847-848

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Passing on Political Information between Major Powers: The Key Role of Ambassadors between Byzantium and some of its Neighbours     

Nicolas Drocourt 《Al-Masaq: Islam & the Medieval Mediterranean》2012,24(1):91-112

Ambassadors and embassies were numerous between Byzantium and its Muslim and Western Christian neighbours during the Middle Byzantine Period. This article seeks to demonstrate that these official envoys constituted major players involved in the transfer of political information between the courts considered. Ambassadors were those who travelled the most in the Mediterranean area during our period – at least between 700 and 900. Furthermore, as official envoys acting for sovereigns, they were carefully listened to by those sovereigns when they returned. Information coming from ambassadors is found in various sources and concerned military matters and foreign policy. But we also find precise data on domestic affairs and internal political information. Furthermore, news of usurpations and troubles in Byzantium may have constituted an important part of the information transferred beyond the Empire. Foreign ambassadors witnessed usurpations and palace revolutions. Their testimonies could have nourished the idea of a Byzantine government weakened by political instability and this theme became prominent during the twelfth century in some Western Christian courts.  相似文献