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101.
A defining characteristic of contemporary trends in global education policy is the promotion of STEM learning in the primary, secondary, and tertiary sectors of education as a means to generate innovation and prosperity in the economy. Intertwined with common sensical assumptions about future labor markets and the transformative potential of technology in education, STEM has become a hegemonic discourse informing policy formation and educational practice. In Gramscian terms, the struggle over STEM as a discursive practice, between proponents of instrumental learning of marketable economic skills and those of education towards humanistic goals, reveals insights about the ideological characteristics of the push for STEM learning. This article explores the power dynamics behind the push for STEM learning as an ideological discourse propagated by global networks of elite policy actors and enacted by non-elite policy actors at the school level. The findings point toward a disjuncture between the discourse of elite policy actors in the US, the realities of STEM labor markets, and the actualization of this policy discourse into classroom practice. The implications of this study indicate that analyses of vertical power relations in network governance in STEM education should attend to the semiotics, materiality, and mutability of networked spaces.  相似文献   
102.
The impact of Nordic walking training on the gait of the elderly   总被引:1,自引:0,他引:1  
The purpose of the current study was to define the impact of regular practice of Nordic walking on the gait of the elderly. Thereby, we aimed to determine whether the gait characteristics of active elderly persons practicing Nordic walking are more similar to healthy adults than that of the sedentary elderly. Comparison was made based on parameters computed from three inertial sensors during walking at a freely chosen velocity. Results showed differences in gait pattern in terms of the amplitude computed from acceleration and angular velocity at the lumbar region (root mean square), the distribution (Skewness) quantified from the vertical and Euclidean norm of the lumbar acceleration, the complexity (Sample Entropy) of the mediolateral component of lumbar angular velocity and the Euclidean norm of the shank acceleration and angular velocity, the regularity of the lower limbs, the spatiotemporal parameters and the variability (standard deviation) of stance and stride durations. These findings reveal that the pattern of active elderly differs significantly from sedentary elderly of the same age while similarity was observed between the active elderly and healthy adults. These results advance that regular physical activity such as Nordic walking may counteract the deterioration of gait quality that occurs with aging.  相似文献   
103.
This study assessed the influence of training load, exposure to match play and sleep duration on two daily wellbeing measures in youth athletes. Forty-eight youth athletes (age 17.3 ± 0.5 years) completed a daily wellbeing questionnaire (DWB), the Perceived Recovery Status scale (PRS), and provided details on the previous day’s training loads (TL) and self-reported sleep duration (sleep) every day for 13 weeks (n = 2727). Linear mixed models assessed the effect of TL, exposure to match play and sleep on DWB and PRS. An increase in TL had a most likely small effect on muscle soreness (= ?0.43;± 0.10) and PRS (= ?0.37;± 0.09). Match play had a likely small additive effect on muscle soreness (= ?0.26;± 0.09) and PRS (= ?0.25;± 0.08). An increase in sleep had a most likely moderate effect on sleep quality (d = 0.80;± 0.14); a most likely small effect on DWB (= 0.45;± 0.09) and fatigue (= 0.42;± 0.11); and a likely small effect on PRS (= 0.25;± 0.09). All other effects were trivial or did not reach the pre-determined threshold for practical significance. The influence of sleep on multiple DWB subscales and the PRS suggests that practitioners should consider the recovery of an athlete alongside the training stress imposed when considering deviations in wellbeing measures.  相似文献   
104.
Strength training with isometric contractions produces large but highly angle-specific adaptations. To contrast the contractile mode of isometric versus dynamic training, but diminish the strong angle specificity effect, we compared the strength gains produced by isometric training at four joint angles with conventional dynamic training. Thirty-three recreationally active healthy males aged 18?–?30 years completed 9 weeks of strength training of the quadriceps muscle group three times per week. An intra-individual design was adopted: one leg performed purely isometric training at each of four joint angles (isometrically trained leg); the other leg performed conventional dynamic training, lifting and lowering (dynamically trained leg). Both legs trained at similar relative loads for the same duration. The quadriceps strength of each leg was measured isometrically (at four angles) and isokinetically (at three velocities) pre and post training. After 9 weeks of training, the increase in isokinetic strength was similar in both legs (pooled data from three velocities: dynamically trained leg, 10.7%; isometrically trained leg, 10.5%). Isometric strength increases were significantly greater for the isometrically trained leg (pooled data from four angles: dynamically trained leg, 13.1%; isometrically trained leg, 18.0%). This may have been due to the greater absolute torque involved with isometric training or a residual angle specificity effect despite the isometric training being divided over four angles.  相似文献   
105.
ABSTRACT

The aims of this study were (a) to compare players’ physical demands between different playing positions in elite U18 basketball games and (b) to identify different clusters of performance. Data were collected from 94 male subjects (age: 17.4 ± 0.7 years), competing in a Euroleague Basketball Tournament. Guards covered a greater relative distance than centres and forwards (small to moderate effect). Forwards and guards had more peak accelerations, high accelerations and high decelerations than centres (moderate to large effects). A cluster analysis allowed to classify all cases into three different groups (Lower, Medium and Higher activity demands), containing 37.4%, 52.8% and 9.8% of the cases, respectively. The high accelerations, high decelerations, peak accelerations and total distance covered were the variables that most contributed to classify the players into the new groups. The percentage of cases distributed in the clusters according to playing position, game type (worst vs worst, mixed opposition, best vs best) and team were different. Centres have lower physical demands specially related with the number of accelerations and decelerations at high intensity and the peak acceleration when compared with guards. Each team has a different activity profile, that does not seem to influence the tournament outcome.  相似文献   
106.
Purpose: The purpose of this study was to examine the association between objectively measured physical activity and hearing sensitivity among a nationally representative sample of U.S. adults with diabetes. Method: Data from the 2003–2006 National Health and Nutrition Examination Survey were used. One hundred eighty-four U.S. adults with diabetes wore an ActiGraph 7164 accelerometer and had their hearing function objectively assessed. A negative binomial logistic regression was used to examine the association between moderate-to-vigorous physical activity (MVPA) and hearing sensitivity. Results were adjusted for age, gender, race/ethnicity, education, body mass index, comorbidity index, marital status, cotinine, homocysteine, high-density lipoprotein cholesterol, glycohemoglobin (HbA1c), C-reactive protein, microalbuminuria, noise exposure, and vision impairment. Results: Compared to those with hearing within normal limits, results showed that participants with mild hearing loss and moderate or greater hearing loss, respectively, engaged in 93% fewer minutes of MVPA (incident rate ratio = 0.07; 95% CI [0.01, 0.60]) and 94% fewer minutes of MVPA (incident rate ratio = 0.06; 95% CI [0.01, 0.54]). Conclusion: Adults with diabetes who have greater hearing impairment are less physically active. Future research is needed to determine the direction of causality.  相似文献   
107.
Message routing in mobile delay tolerant networks inherently relies on the cooperation between nodes. In most existing routing protocols, the participation of nodes in the routing process is taken as granted. However, in reality, nodes can be unwilling to participate. We first show in this paper the impact of the unwillingness of nodes to participate in existing routing protocols through a set of experiments. Results show that in the presence of even a small proportion of nodes that do not forward messages, performance is heavily degraded. We then analyze two major reasons of the unwillingness of nodes to participate, i.e., their rational behavior (also called selfishness) and their wariness of disclosing private mobility information.  相似文献   
108.
Peer assessment provides a useful mechanism to develop many positive qualities in students studying in higher education (HE). Potential influences on peer‐awarded marks include student qualities such as gender, HE background (e.g. university affiliation) and participation in the development of the assessment criteria. Many studies that have investigated peer assessment have placed great emphasis on marks from a single tutor, or very few tutors, from a single university. This study examined grades awarded by 11 tutors (affiliated with four universities) to oral presentations delivered on a residential field course by second‐year undergraduate students from two universities studying environmental or biological disciplines. Student assessors awarded marks of fairly high precision (correlating strongly with tutor grades) but averaged 5% higher than their tutors (i.e. of only moderate accuracy). Marginally higher marks (circa 1.6%) were awarded by student assessors to speakers studying at the same university. Gender influences were detected as males tended to grade other male speakers very slightly more highly than female speakers. Marks from females were unaffected by speaker gender. Students who participated in the development of the assessment criteria did not achieve higher grades for their presentations. However, when these ‘participants’ were assessing, they awarded lower marks than their peers (i.e. closer to, but not as low as, those awarded by tutors). Lower marks were also awarded during the middle of sessions, possibly resulting from factors associated with motivation and attention of speakers and markers. Overall, the potential biases in marking by naive assessors examined in this study may influence the validity of marks generated by peer assessment schemes, but the experience of this type of assessment had positive effects on those involved.  相似文献   
109.
There has recently been a renewed interest in three types of comparability of standards in the United Kingdom [1] public examination system: between years, between subjects and between the six examination boards. Whilst comparisons of raw grade distributions are now generally acknowledged to be invalid indicators of relative standards, comparisons are regularly made for this purpose between adjusted grade distributions. Such adjustments are typically the result of statistically controlling for some of the relevant variables. The dangers of such an approach are that only easily quantifiable variables are used in the adjustment and that any residual differences between distributions will automatically be attributed to difference in standard. Using candidate‐level data from four 1994 Advanced level (A level) [2] mathematics examinations (designed for 18‐year‐old students), and paying particular attention to the Schools’ Mathematics Project (SMP) 16‐19 [3] syllabus, the paper reports on two such analyses. It then discusses some reasons why attributing differences in the adjusted grade distribution to differences in standard could be invalid. Whilst the study focuses on four A level mathematics syllabuses, the same principles apply irrespective of the context in which statistical comparisons of examination results are made. The methodologies, their shortcomings and the pleas for caution are not, therefore, specific to this study, this type of comparison or this examination system.  相似文献   
110.
This article discusses the potential significance of name writing skills in addressing many important questions about the development of early literacy skills. Young children are inherently interested in producing their own names in print. Furthermore, young children appear to construct their understandings of name writing skills in a predictable, sequential pattern. Questions raised include whether the development of name writing skills mirrors the development of other important cognitive skills, the potential of name writing skills to offer insight as to how young children learn important literacy concepts, the use of name writing as a developmental indicator for children that may be at risk for reading difficulties, and the potential for structured activities using name writing to facilitate the development of emergent literacy skills.  相似文献   
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