Validation of two accelerometers to determine mechanical loading of physical activities in children     

Ursina Meyer  Dominique Ernst  Silvia Schott  Claudia Riera  Jan Hattendorf  Jacqueline Romkes 《Journal of sports sciences》2015,33(16):1702-1709

The purpose of this study was to assess the validity of accelerometers using force plates (i.e., ground reaction force (GRF)) during the performance of different tasks of daily physical activity in children. Thirteen children (10.1 (range 5.4–15.7) years, 3 girls) wore two accelerometers (ActiGraph GT3X+ (ACT), GENEA (GEN)) at the hip that provide raw acceleration signals at 100 Hz. Participants completed different tasks (walking, jogging, running, landings from boxes of different height, rope skipping, dancing) on a force plate. GRF was collected for one step per trial (10 trials) for ambulatory movements and for all landings (10 trials), rope skips and dance procedures. Accelerometer outputs as peak loading (g) per activity were averaged. ANOVA, correlation analyses and Bland–Altman plots were computed to determine validity of accelerometers using GRF. There was a main effect of task with increasing acceleration values in tasks with increasing locomotion speed and landing height (P < 0.001). Data from ACT and GEN correlated with GRF (r = 0.90 and 0.89, respectively) and between each other (r = 0.98), but both accelerometers consistently overestimated GRF. The new generation of accelerometer models that allow raw signal detection are reasonably accurate to measure impact loading of bone in children, although they systematically overestimate GRF.  相似文献   

Genetic and Environmental Etiologies of the Longitudinal Relations Between Prereading Skills and Reading          下载免费PDF全文

Micaela E. Christopher  Jacqueline Hulslander  Brian Byrne  Stefan Samuelsson  Janice M. Keenan  Bruce Pennington  John C. DeFries  Sally J. Wadsworth  Erik Willcutt  Richard K. Olson 《Child development》2015,86(2):342-361

The present study explored the environmental and genetic etiologies of the longitudinal relations between prereading skills and reading and spelling. Twin pairs (n = 489) were assessed before kindergarten (M = 4.9 years), post‐first grade (M = 7.4 years), and post‐fourth grade (M = 10.4 years). Genetic influences on five prereading skills (print knowledge, rapid naming, phonological awareness, vocabulary, and verbal memory) were primarily responsible for relations with word reading and spelling. However, relations with post‐fourth‐grade reading comprehension were due to both genetic and shared environmental influences. Genetic and shared environmental influences that were common among the prereading variables covaried with reading and spelling, as did genetic influences unique to verbal memory (only post‐fourth‐grade comprehension), print knowledge, and rapid naming.  相似文献   

Antiracism defined as equitable sociocultural interactions in prekindergarten: Classroom racial composition makes a difference     

Stephanie M. Curenton  Shana E. Rochester  Jacqueline Sims  Nneka Ibekwe-Okafor  Iheoma U. Iruka  Arlene G. García-Miranda  Jessica Whittaker 《Child development》2022,93(3):681-698

This study used secondary data from the My Teaching Partner-Math/Science 2013–2016 randomized control trial to explore whether equitable sociocultural classroom interactions (see Curenton et al., 2019) were associated with the skills of 105 four- and five-year-olds (52% boys; drawn from 20 unique video recordings of preschool teachers/classrooms; 43% were Black, Latine, Asian, or other racially marginalized learners). Equitable interactions predicted children's skills with effect sizes ranging from small (0.01–0.44) to large (1.00). Moderation analyses revealed that when classrooms had more racially marginalized learners, teachers’ use of equitable disciplinary and personalized learning practices were associated with higher executive functioning gains across prekindergarten. Findings illustrate how classroom composition can be a key indicator between equitable classroom interactions and young children's early skills.  相似文献   

Employment and further study outcomes for care-experienced graduates in the UK     

Harrison  Neil  Baker  Zoë  Stevenson  Jacqueline 《Higher Education》2022,83(2):357-378

Higher Education - Life outcomes for people who spent time in the care of the state as children (‘care-experienced’) are known to be significantly lower, on average, than for the...  相似文献   

Effect of chainring ovality on joint power during cycling at different workloads and cadences     

Gerda Strutzenberger  Tobias Wunsch  Josef Kroell  Jacqueline Dastl  Hermann Schwameder 《Sports biomechanics / International Society of Biomechanics in Sports》2014,13(2):97-108

Non-circular chainrings theoretically enhance cycling performance by increasing effective chainring diameter and varying crank velocity, but research has failed to consistently reproduce the benefits in cycling trials. The aim of this study was (1) to investigate the effect of different chainring shapes on sagittal knee joint moment and sagittal lower limb joint powers and (2) to investigate whether alterations are affected by cadence and workload. Fourteen elite cyclists cycled in six conditions (70, 90 and 110 rpm, each at 180 and 300 W), for 2 min each, using three chainrings of different ovalities (1.0–1.215). Kinematic data and pedal forces were collected. For most conditions, only the chainring with the highest ovality (1.215) was characterised by smaller sagittal knee joint moments, smaller relative sagittal knee joint power contribution and larger relative sagittal hip joint power contribution, which suggests a change from maximising efficiency to maximising power production. Effect sizes increased with higher cadences, but not with higher workload. This study has application for athletes, clinicians and sports equipment industry as a non-circular chainring can change joint-specific power generation and decrease knee joint moment, but certain ovality seems to be necessary to provoke this effect.  相似文献   

Face-to-face contact in blended learning for intercultural education: the role of teachers     

Roger Austin  Angela Rickard  Jacqueline Reilly 《Irish Educational Studies》2017,36(3):323-340

In societies experiencing or emerging from conflict, teachers often deliver educational programmes designed to build community cohesion. We report on research which examined teachers’ views of the implementation of a programme involving both face-to-face and online contact between pupils. Findings suggest that this blended approach is highly motivational, enhancing online work and relationship building. The research underlines the importance of the political, educational and historical context for work of this sort and the impact this has on the particular blend of online and face-to-face interaction. Implications for policymakers and teachers include value for money and sustainability of blended intercultural education in similar contexts.  相似文献   

The influence of academic culture on quality management system ISO 9001 maintenance within Malaysian universities     

Siti Arni Basir  John Davies  Jacqueline Douglas  Alexander Douglas 《Journal of Higher Education Policy & Management》2017,39(3):320-340

This study investigates the influence of the elements of academic culture on quality management system ISO 9001 maintenance within Malaysian universities. There is a dearth of empirical studies on maintaining ISO 9001, particularly in the higher education context. From the literature review, academic culture was classified according to four elements – academic freedom, individualism, professionalism and collegiality. Two case studies were conducted within Malaysian universities that had been ISO 9001-certified for 5 years. At the time of this research, these two were the only universities that had certification for their entire organisation. (Most organisations gain certification for specific departments). The findings showed that academic freedom, individualism and collegiality had worked against ISO 9001 maintenance, while professionalism had influenced ISO 9001 maintenance both positively and negatively. The opposites of individualism (teamwork) and collegiality (managerialism) had supported ISO 9001 maintenance in one of the cases.  相似文献   

Early contribution of phonological awareness and later influence of phonological memory throughout reading acquisition     

Christelle Nithart  Elisabeth Demont  Marie‐Noëlle Metz‐Lutz  Steve Majerus  Martine Poncelet  Jacqueline Leybaert 《Journal of Research in Reading》2011,34(3):346-363

The acquisition of reading skills is known to rely on early phonological abilities, but only a few studies have investigated the independent contribution of the different steps involved in phonological processing. This 1‐year longitudinal study, spanning the initial year of reading instruction, aimed at specifying the development of phonological discrimination, awareness and various aspects of phonological memory and at assessing their respective contributions to early reading acquisition. Our results show an increase in performance at each phonological processing step, but also suggest a qualitative evolution in their relative importance. Hierarchical regression analyses indicate that reading skills are mainly predicted by phonological awareness measured at the kindergarten stage and, subsequently, by phonological memory abilities measured at the end of first grade. More precisely short‐term memory for serial‐order information seems to contribute to the development of decoding abilities, while phonological knowledge stored in long‐term memory seems to influence word recognition.  相似文献   

Teaching Science Inquiry in Urban Contexts: The Role of Elementary Preservice Teachers’ Beliefs     

Jacqueline Leonard  Joy Barnes-Johnson  Scott Jackson Dantley  Charles Kimber 《The Urban Review》2011,43(1):124-150

This paper reports on a study of elementary preservice teachers’ inquiry-based practices, their efficacy beliefs, and the role beliefs had on two preservice teachers’ practices in urban classrooms. Results show inquiry-based practices can be cultivated through field-based experiences and preservice teachers’ efficacy beliefs, as it relates to practice in urban settings, are malleable. Specifically, personal efficacy beliefs about teaching science improved or were sustained for one cohort of preservice teachers. However, beliefs about students’ ability to learn science, that is outcome beliefs, were less stable. The results of two case studies show that science content knowledge was a factor in preservice teachers’ inquiry-based practices. However, why preservice teachers’ beliefs about student learning declined is less clear. More research is needed, along with follow-up data on teacher induction, to learn how preservice teachers’ beliefs impact urban students’ science education.  相似文献   

The kalamazoo zoo     

Jacqueline Dembar Greene 《Early Childhood Education Journal》1977,5(2):38-39

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