Active relatives and health-related physical fitness in European adolescents: The HELENA Study     

M Martín-Matillas  FB Ortega  JR Ruiz  D Martínez-Gómez  G Vicente-Rodríguez  A Marcos  L Béghin  A Kafatos  M González-Gross  M Zaccaria  D Molnár  S De Henauw  M Sjöström  LA Moreno  MJ Castillo On Behalf Of The Helena Study 《Journal of sports sciences》2012,30(13):1329-1335

Abstract High physical fitness in childhood and adolescence is positively associated with favourable health-related outcomes. Our aim was to examine the relationship between relatives' (father, mother, brother, sister, and best friend) physical activity engagement and encouragement on adolescents' physical fitness. Adolescents were part of the HELENA study, a multi-centre study conducted in 10 cities from nine European countries in 2006-2008. Participants were 3288 adolescents (48% boys, 52% girls) aged 12.5-17.5 years with valid data on at least one of the three fitness variables studied: muscular strength (standing long jump), speed/agility (4×10 m shuttle run), and cardiorespiratory fitness (20 m shuttle run). The adolescents reported their relatives' physical activity engagement and encouragement. Analysis of covariance showed that relatives' physical activity engagement (father, mother, brother, and best friend) was positively related to cardiorespiratory fitness (P?相似文献   

Characterizing the mechanical parameters of forward and backward falls as experienced in snowboarding     

Schmitt KU  Wider D  Michel FI  Brügger O  Gerber H  Denoth J 《Sports biomechanics / International Society of Biomechanics in Sports》2012,11(1):57-72

Wrist injuries are frequently observed after falls in snowboarding. In this study, laboratory experiments mimicking forward and backward falls were analysed. In six different falling scenarios, participants self-initiated falls from a static initial position. Eighteen volunteers conducted a total of 741 trials. Measurements were taken for basic parameters describing the kinematics as well as the biomechanical loading during impact, such as impact force, impact acceleration, and velocity. The effective mass affecting the wrist in a fall also was determined. The elbow angle at impact showed a more extended arm in backward falls compared to forward falls, whereas the wrist angle at impact remained similar in forward and backward falls. The study results suggest a new performance standard for wrist guards, indicating the following parameters to characterize an impact: an effective mass acting on one wrist of 3-5 kg, an impact angle of 75 degrees of the forearm relative to the ground, and an impact velocity of 3 m/s.  相似文献   

Write when hot — submit when not: seasonal bias in peer review or acceptance?     

Shaul SHALVI  Matthijs BAAS  Michel J. J. HANDGRAAF  Carsten K.W. DE DREU 《Learned Publishing》2010,23(2):117-123

At a top psychology journal, Psychological Science (PS), submissions peak during the summer months. We tested whether this seasonal submission bias decreases the likelihood of a paper being accepted in that period. Month of submission data was obtained for all 575 publications in PS for the period 2003–2006. Whereas submissions to PS were higher in the summer, there was no evidence that most accepted publications were originally submitted in the summer. Thus, contributors submit to PS when the likelihood of acceptance is the lowest – creating their own entrance barrier. A similar seasonal pattern was not identified for Personality and Social Psychology Bulletin, another top psychology journal. Using the Web of Knowledge database, we further assessed whether overcoming the seasonal entrance barrier influences the number of citations a paper receives in subsequent years. We discuss the possibility that the different rejections policies in the two journals, employing desk rejections or not, may explain this discrepancy, and explore a range of alternative hypotheses.  相似文献   

Citing-side normalization of journal impact: A robust variant of the Audience Factor     

Michel Zitt 《Journal of Informetrics》2010,4(3):392-406

The principle of a new type of impact measure was introduced recently, called the “Audience Factor” (AF). It is a variant of the journal impact factor where emitted citations are weighted inversely to the propensity to cite of the source. In the initial design, propensity was calculated using the average length of bibliography at the source level with two options: a journal-level average or a field-level average. This citing-side normalization controls for propensity to cite, the main determinant of impact factor variability across fields. The AF maintains the variability due to exports–imports of citations across field and to growth differences. It does not account for influence chains, powerful approaches taken in the wake of Pinski–Narin's influence weights. Here we introduce a robust variant of the audience factor, trying to combine the respective advantages of the two options for calculating bibliography lengths: the classification-free scheme when the bibliography length is calculated at the individual journal level, and the robustness and avoidance of ad hoc settings when the bibliography length is averaged at the field level. The variant proposed relies on the relative neighborhood of a citing journal, regarded as its micro-field and assumed to reflect the citation behavior in this area of science. The methodology adopted allows a large range of variation of the neighborhood, reflecting the local citation network, and partly alleviates the “cross-scale” normalization issue. Citing-side normalization is a general principle which may be extended to other citation counts.  相似文献   

General Growth Mixture Analysis of Adolescents' Developmental Trajectories of Anxiety: The Impact of Untested Invariance Assumptions on Substantive Interpretations     

Alexandre J. S. Morin  Christophe Maïano  Benjamin Nagengast  Herbert W. Marsh  Julien Morizot  Michel Janosz 《Structural equation modeling》2013,20(4):613-648

Substantively, this study investigates potential heterogeneity in the developmental trajectories of anxiety in adolescence. Methodologically, this study demonstrates the usefulness of general growth mixture analysis (GGMA) in addressing these issues and illustrates the impact of untested invariance assumptions on substantive interpretations. This study relied on data from the Montreal Adolescent Depression Development Project (MADDP), a 4-year follow-up of more than 1,000 adolescents who completed the Beck Anxiety Inventory each year. GGMA models relying on different invariance assumptions were empirically compared. Each of these models converged on a 5-class solution, but yielded different substantive results. The model with class-varying variance–covariance matrices was retained as providing a better fit to the data. These results showed that although elevated levels of anxiety might fluctuate over time, they clearly do not represent a transient phenomenon. This model was then validated in relation to multiple predictors (mostly related to school violence) and outcomes (grade-point average, school dropout, depression, loneliness, and drug-related problems).  相似文献   

Learning for an Active Citizenship and Working Life: Main Challenges and Ongoing Innovations     

Alain Michel 《European Journal of Education》2015,50(4):379-382

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法新社：NewsML 标准的同路人     

Laurent Le Meur 《中国传媒科技》2008,(4):51-51

参加IPTC北京年会的法新社多媒体实验室主任、资深媒体技术、新闻技术标准专家Laurent Le Meur先生4月3日在新华社的技术研讨会上,首先介绍了法新社的新闻业务和技术概况,他说：法新社每天播发及时、精确、深度报道,每天有遍及世界165个国家的2900名员工为其工作,每天播发视频、图片、图表和多媒体稿件,法新社每天发布的多媒体稿件达350～600篇左右,每天播发的各类新闻大多遵循了NewsML标准。  相似文献   

A Grounded Theory of Counselor Educators' Academic Leadership Development     

Danica G. Hays  Stephanie A. Crockett  Rebecca Michel 《Counselor Education & Supervision》2021,60(1):51-72

Counselor educators are well‐equipped to serve as academic leaders, yet little is known about what factors influence their engagement experiences. This grounded theory provides a theoretical model of academic leadership engagement based on interviews with 20 counselor educators with academic leadership experience. Implications for facilitating academic leadership engagement are provided.  相似文献   

Archaeology in the Capital of Molecular Biology     

Morange  Michel 《Metascience》2003,12(2):195-197

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Educational Policy Formulation during the Johnson Administration     

George J. Michel 《Journal of educational administration and history》1990,22(2):38-52

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