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261.
Two studies investigated whether parent–child discussion of peer provocations reduces young children's hostile attributional bias. Study 1 (= 109, age 4–7)—an observational study—showed that parent–child discussion of nonhostile attributions (when reading a picture book) predicted reductions in children's hostile attributional bias from pre‐ to postdiscussion. Study 2 (= 160, age 4–6)—an experimental study—showed that stimulating parents to discuss either nonhostile attributions or normative beliefs (vs. a control condition) reduced children's hostile attributional bias in response to hypothetical vignettes, but not in response to a staged peer provocation. These findings suggest that by framing social situations, parents may help their children perceive less hostility in their social worlds.  相似文献   
262.
This article examines how education unfolded as a science in Estonia in the period 1944–1991, i.e. from the second Soviet occupation to the fall of the USSR. Historical analysis of the way prominent scholars and institutions succeeded in overcoming the adverse conditions of that period is conducted by viewing their respective contributions through two theoretical lenses: cultural trauma theory to explore the adversities they had to contend with, and resilience theory to explain how those challenges were overcome. Through these means an account is constructed of how individuals and institutions succeeded in preserving the national Estonian and inter-war European legacy of educational philosophy, in the process confronting and countering adverse socio-cultural-political conditions.  相似文献   
263.
Mechanical power output is a key performance-determining variable in many cyclic sports. In rowing, instantaneous power output is commonly determined as the dot product of handle force moment and oar angular velocity. The aim of this study was to show that this commonly used proxy is theoretically flawed and to provide an indication of the magnitude of the error. To obtain a consistent dataset, simulations were performed using a previously proposed forward dynamical model. Inputs were previously recorded rower kinematics and horizontal oar angle, at 20 and 32 strokes?min?1. From simulation outputs, true power output and power output according to the common proxy were calculated. The error when using the common proxy was quantified as the difference between the average power output according to the proxy and the true average power output (P?residual), and as the ratio of this difference to the true average power output (ratiores./rower). At stroke rate 20, P?residual was 27.4 W and ratiores./rower was 0.143; at stroke rate 32, P?residual was 44.3 W and ratiores./rower was 0.142. Power output in rowing appears to be underestimated when calculated according to the common proxy. Simulations suggest this error to be at least 10% of the true power output.  相似文献   
264.
265.
For a valid determination of a rower’s mechanical power output, the anterior–posterior (AP) acceleration of a rower’s centre of mass (CoM) is required. The current study was designed to evaluate the accuracy of the determination of this acceleration using a full-body inertial measurement units (IMUs) suit in combination with a mass distribution model. Three methods were evaluated. In the first two methods, IMU data were combined with either a subject-specific mass distribution or a standard mass distribution model for athletes. In the third method, a rower’s AP CoM acceleration was estimated using a single IMU placed at the pelvis.

Experienced rowers rowed on an ergometer that was placed on two force plates, while wearing a full-body IMUs suit. Correspondence values between AP CoM acceleration based on IMU data (the three methods) and AP CoM acceleration obtained from force plate data (reference) were calculated. Good correspondence was found between the reference AP CoM acceleration and the AP CoM accelerations determined using IMU data in combination with the subject-specific mass model and the standard mass model (intraclass correlation coefficients [ICC] >?0.988 and normalized root mean square errors [nRMSE]?3.81%). Correspondence was lower for the AP CoM accelerations determined using a single pelvis IMU (0.877?Based on these results, we recommend determining a rower’s AP CoM acceleration using IMUs in combination with the standard mass model. Finally, we conclude that accurate determination of a rower’s AP CoM acceleration is not possible on the basis of the pelvis acceleration only.  相似文献   
266.
This paper details findings from an evaluation of a gender-transformative sexual and reproductive health and rights group education programme facilitated with young men aged 15–24 years in South Africa. A total of 475 young men participated in the group education programme. A self-administered pre- and post-questionnaire survey was conducted with a sample of the participants, and focus group discussions were facilitated. A total of 265 young men completed both the pre and post-questionnaires. Findings from the surveys as well as the focus group discussions showed positive changes in gender equitable attitudes, contraception and condom use. Results indicate that the young men who participated in the group education learned to identify harmful gender norms and actively questioned these constructs both within their personal lives and in the broader community. The intervention enabled some participants to envision alternative versions of masculinity and femininity, thus enabling them to adopt a new way of being, with transformed attitudes concerning household and gender roles.  相似文献   
267.
This study reports on a large-scale survey on primary school teachers’ perceptions of being change agents and the extent to which these perceptions are related to personality and contextual factors. A principal component analysis and confirmatory factor analysis revealed nine characteristics of teachers as change agents. Personality and contextual factors are related to teachers’ perceptions of being a change agent. Four teacher profiles were distinguished according to the varying degrees of teachers’ perceptions of themselves as change agents. This study adds to the further understanding of teachers as change agents, their characteristics and how these characteristics are related to personality and contextual factors.  相似文献   
268.
Background:Physical activity(PA)has substantial health benefits and is important in combatting chronic diseases,which have been associated with elevated levels of advanced glycation endproducts(AGEs).AGEs play a role in the aging process,and an association between PA and AGEs has been reported.We aimed to investigate the relationship between PA and AGE accumulation in a general population and in a population with chronic diseases.Methods:This large cross-sectional population study used data from adult participants in the LifeLines project,with participant information drawn from the LifeLines database as well data from patients with diabetes mellitus or renal and/or cardiovascular diseases.Tissue AGE accumulation was assessed non-invasively by skin-autofluorescence(SAF)using an AGE reader(DiagnOptics Technologies BV,Groningen,the Netherlands).PA was assessed using the short questionnaire to assess health-enhancing physical activity(SQUASH).Multivariate linear regression analyses were adjusted for age,body mass index,sex,and smoking status.Results:Data from 63,452 participants(general population n=59,177,chronic disease n=4275)were analyzed.The general population was significantly younger(43.58±11.77 years,mean±SD)and had significantly lower SAF(1.90±0.42 arbitrary units(AU))compared to the population with chronic disease(age:55.51±12.07 years;SAF:2.27±0.51 AU).In the group with chronic disease,more hours of moderate to vigorous physical activities per week were associated with lower SAF(β=-0.002,95%confidence interval(95%CI):-0.002 to-0.001).For the general population,there was no association between hours of moderate to vigorous activity and SAF(β=3.2×10-5,95%CI:0.000-0.001,p=0.742).However,there was an association in the general population between total hours of PA per week and SAF(β=4.2×10-4,95%CI:0.000-0.001,p<0.001),but this association was not found in the chronic disease population(β=-3.2×10-4,95%CI:-0.001 to 0.000,p=0.347).Conclusion:Our study demonstrates that an inverse relationship exists between PA and AGE accumulation in the population with chronic disease.More hours of moderate to vigorous activity is associated a significantly decreased SAF.More PA is associated a lower SAF,even after for the established predictors(age,body mass index,smoking status,and sex).Our findings could help to promote health and prolong longevity.  相似文献   
269.
Abstract

Rowers sit on a seat that slides relative to the boat/ergometer. If a rower lifts him or herself from this sliding seat at any time, the seat will move away from under them and the rowing action is disrupted. From a mechanical perspective, it is clear that the need for the rower to remain in contact with the sliding seat at all times imposes position-dependent constraints on the forces exerted at the oar handle and the footstretcher. Here we investigate if the mechanical power output during rowing, which is strongly related to these forces, might be improved if the contact with the sliding seat was of no concern to the rower. In particular, we examine if elimination of these constraints by strapping the rower to the sliding seat leads to an increase in performance during the start on a standard rowing ergometer. Eleven well-trained female rowers performed 5-stroke starts in normal and strapped conditions. Handle force, vertical seat force, footstretcher force, and handle kinematics were recorded, from which mechanical power and work output were calculated. Most of the relevant mechanical variables differed significantly between the normal and strapped conditions. Most importantly, mechanical power output (averaged over the 5-stroke start) in the strapped condition was 12% higher than in the normal condition. We conclude that strapping a rower's pelvis to the sliding seat allows more vigorous execution of the stroke phases, resulting in a substantial improvement in performance during the start of ergometer rowing.  相似文献   
270.
Abstract

The birth date distributions of elite male and female footballers in Australia, from junior youth (age 14 and upwards) to senior (professional) players, were examined. A statistically significant relative age effect was found among junior male players, reducing in effect with increasing age. An inter-year relative age effect that became apparent among the players at national level in the Under-17 and Under-20 age groups, due to the timing of the respective World Cups for those age groups, was also identified. It is conjectured that this might lead to players born in certain years having a curtailed pathway in the elite game, leading to drop-out among this very elite group. In the case of women elite players, no significant relative age effect was found among youth players, possibly due to less fierce competition for places, although a significant effect was found to exist at senior elite level.  相似文献   
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