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51.
Laurent Liégeois G′erard Chasseigne Sophie Papin Etienne Mullet 《International Journal of Science Education》2013,35(9):1129-1145
This paper reports two studies into the understanding of the concept of potential difference in the current-potential difference-resistance context among 8th-12th graders (Study 1), and the efficiency of a learning device derived from Social Judgment Theory (Study 2). These two studies showed that: (a) when asked to infer potential difference from resistance and current information, most participants only relied on current and ignored or greatly underestimated the importance of resistance information; (b) exposure to an electricity course did not much alter the way participants infer potential difference from resistance and current information; (c) a simple learning device considerably improved the way participants infer potential difference from resistance and current information; and (d) this observed improvement promised to be durable, at least in the short term. 相似文献
52.
The present study investigated the development of linguistic awareness in children exposed to the early learning of a second language in Grades 3–5 of primary school, i.e. between the ages of 8 and 10. The aim was to determine whether this bilingual experience enhanced the development of phonological awareness in beginning readers in a bilingual French-regional language school programme compared with a population of monolingual children receiving traditional education. More specifically, in light of research promoting the hypothesis of a “bilingual advantage”, we set out to determine exactly how long children need to be exposed to a second language before bilingualism starts to influence the development of their phonological awareness. Tasks designed to assess phonological awareness were administered to more than a hundred children. Results suggest that children who have undergone a bilingual school programme display a more highly developed phonological awareness than their monolingual peers from age 9 onwards, i.e. in Grade 4. These results are discussed in the light of ongoing research on bilingualism, bilingual education and threshold theory. 相似文献
53.
This study aimed to investigate the acute effects of two barbell hip thrust-based post-activation potentiation (PAP) protocols on subsequent sprint performance. Using a crossover design, eighteen soccer athletes performed 5 m, 10 m, and 20 m sprints before and 15 s, 4 min, and 8 min after two PAP protocols. The PAP conditioning activities consisted of hip thrust exercises loaded with either 85% 1RM or a load for optimum power development. The resulting 5 m and 10 m sprint performances were impaired at 15 s following both protocols. At 4 min and 8 min, meaningful improvements were observed for the three sprint distances following both of the protocols. Meaningful differences were found when comparing the two PAPs over time: greater impairments in 5 m and 10 m following the 85% of 1 RM protocol after 15 s, and greater improvements in all sprint distances after 4 min and 8 min following the optimum power development protocol. Positive correlations between the hip thrust's 1RM and power values and the overall individual PAP responses were found. This investigation showed that both heavy-loaded and optimum-power hip thrust exercises can induce a PAP response, with the optimum-power development protocol preferred due its higher efficiency. 相似文献
54.
Gabriele Perozzi Denis Efimov Jean-Marc Biannic Laurent Planckaert 《Journal of The Franklin Institute》2018,355(12):4809-4838
The problem of position tracking of a mini drone subject to wind perturbations is investigated. The solution is based on a detailed unmanned aerial vehicle (UAV) model, with aerodynamic coefficients and external disturbance components, which is introduced in order to better represent the impact of the wind field. Then, upper bounds of wind-induced disturbances are characterized, which allow a sliding mode control (SMC) technique to be applied with guaranteed convergence properties. The peculiarity of the considered case is that the disturbance upper bounds depend on the control amplitude itself (i.e. the system is nonlinear in control), which leads to a new procedure for the control tuning presented in the paper. The last part of the paper is dedicated to the analysis and reduction of chattering effects, as well as investigation of rotor dynamics issues. Conventional SMC with constant gains, proposed first order SMC, and proposed quasi-continuous SMC are compared. Nonlinear UAV simulator, validated through in-door experiments, is used to demonstrate the effectiveness of the proposed controls. 相似文献
55.
Heidemarie Laurent 《Parenting, science and practice》2019,19(1-2):94-96
SYNOPSISParental neuroimaging promises to shed light on how humans adapt to the demands of parenthood, but this research is not without challenges. A study in this issue reports differences between mothers’ and non-mothers’ default mode network activation during a goal-oriented task accompanied by human vocalizations. However, they did not find hypothesized differences in response specifically to infant cry, and the reach of conclusions that can be made based on these findings is limited. In my commentary, I present ideas for ways this work could be extended to make more definitive statements about the nature and potential benefits of parental brain adaptations. 相似文献
56.
Ivan Dalley Crozier Susan Hardy David Rutledge Niall Shanks Ian J. Slater Daryn Lehoux Alan Chalmers Shaughan Lavine Richard McDonough Paul Redding Katherine Neal David J. Stump Nicolas Rasmussen Fa-ti Fan David Oldroyd Iain Davidson Hanne Andersen Vassiliki Betty Smocovitis Ivan Crozier Anjan Chakravartty King’s College John Laurent Ian Tyrell Susan Spath Roy MacLeod 《Metascience》2001,10(3):412-506
57.
Caroline Arnoux-Nicolas Laurent Sovet Lin Lhotellier Jean-Luc Bernaud 《International Journal for Educational and Vocational Guidance》2017,17(2):165-185
The purpose of this study was to validate a psychometric instrument among French workers for assessing the meaning of work. Following an empirical framework, a two-step procedure consisted of exploring and then validating the scale among distinctive samples. The consequent Meaning of Work Inventory is a 15-item scale based on a four-factor model, and assesses the importance, understanding, direction, and purpose of work. The results indicate that this instrument is reliable for assessing the meaning of work in the French context. Implications for career counseling practices are discussed. 相似文献
58.
Laurent Vigouroux Marine Devise Théo Cartier Clément Aubert Eric Berton 《Journal of sports sciences》2019,37(8):886-894
Pull-ups are often used by sport-climbers and other athletes to train their arm and back muscle capabilities. Sport-climbers use different types of holds to reinforce finger strength concomitantly. However, the effect of grip types on pull-up performance had not previously been investigated. A vertical force platform sensor measured the force exerted by climbers when performing pull-ups under six different grip conditions (gym-bar, large climbing hold, and four small climbing holds: 22mm, 18mm, 14mm, and 10mm). The electromyography of finger flexors and extensor muscles were recorded simultaneously. The maximal arm power and summed mechanical work were computed. The results revealed that the number of pull-ups, maximal power, and summed mechanical work decreased significantly with the size of the climbing hold used, even if no differences were found between a large climbing hold and a gym-bar. Electromyography of the forearm muscles revealed that the use of a climbing hold generated finger flexor fatigue and that the level of cocontraction was impacted by the different segment coordination strategies generated during the pull-ups. These findings are likely to be useful for quantifying training loads more accurately and designing training exercises and programs. 相似文献
59.
Laurent Chapelle Nikki Rommers Peter Clarys Eva D’Hondt Jan Taeymans 《Journal of sports sciences》2019,37(9):988-997
The aim of this study was to examine the magnitude of upper extremity bone mineral content (BMC) asymmetries in tennis players. Furthermore, the influence of sex (male versus female versus mixed), chronological age (juniors: < 18 years; adults: 18–39 years and seniors: ≥ 40 years) and starting age (early starters: < 14 years and late starters: > 18 years) on these asymmetries were examined. Two databases were searched for scientific articles that examined upper extremity BMC in tennis players. Pooling of the individual study effect sizes was conducted using the random-effects model. Three subgroup analyses were performed based on sex, chronological age and starting age. Out of the 15 included studies 24 effect sizes were extracted resulting in a significant difference in BMC value between the dominant and nondominant upper extremity of the tennis players (Standardised Mean Difference: 0.85 [95% CI: 0.67–1.03]). The three subgroup analyses all showed medium to strong effect sizes and significant intergroup differences. To conclude, BMC was significantly higher in the dominant upper extremity compared to the nondominant upper extremity in tennis players. Nevertheless, the influence of training volume and playing experience on these asymmetries are yet to be examined. 相似文献
60.
The Fukushima accident was a crisis in Japan, and a crisis elsewhere. In Europe, the aftermath of Fukushima was a period of intense questioning, about how to ensure the safety of nuclear reactors, and how, at the same time, ensure the ability of the European Union to act as a consistent political actor in the face of potentially catastrophic risks. Using empirical material related to the post-Fukushima stress tests and the subsequent discussions about the European regulatory framework for nuclear safety, this paper shows that stress tests have provided a peculiar form of European intervention, restabilizing regulatory boundaries while extending the European gaze. It describes the overall operation thereby performed as the “normalization of the crisis” whereby the exceptional situation enters the realm of the normal functioning of the public administrations, and where the actions undertaken take the form of the legal norm.
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