ABSTRACTThe aims of this study were to identify profiles of sedentary behaviour (SB) patterns, based on leisure-time self-reported SB modalities (screen, educative, social, and relaxing) and to evaluate changes in these profiles over 2 years among Spanish youth aged 8–18 years. Latent profile analysis (LPA), a data-driven analytic approach, was used to identify groups of boys and girls (n = 1553; 48% girls; mean±SD age: 12.56 ± 2.49 y) with distinct SB profiles using the SB modalities (time/d) as input variables. Latent transition analysis, an extension of LPA that uses longitudinal data, was used to analyse 2-year changes in these profiles. At baseline, four and three SB profiles were found among boys (labelled: screen, educative, social, and relaxing) and girls (labelled: screen/social, educative, and relaxing), respectively. Overall, more girls (range: 48%-67%) had the same profile over time, than boys (40%-52%). Participants with a screen or relaxing SB profile at baseline were more likely to have an educative profile after 2 years. Youth with a social and an educative SB profile at baseline were more likely to transition to profiles characterized by higher screen and social SB, respectively. Using a novel and person-centered approach, this study identified gender-specific SB profiles that were moderately stable over time. 相似文献
This study evaluated the sampling methods and sample populations used in all U.S.-based survey and experimental mass communication studies published between 2000 and 2014 in six major journals (N = 1,173). Most studies used nonprobability samples, and more than half used student samples. Experiments used more nonprobability and student samples than surveys. Funded studies used more probability and nonstudent samples than nonfunded studies. Implications of results pertaining to population validity and interpretations of findings for mass communication research are discussed. 相似文献
The purpose of this study was to analyse the raw lifting speed collected during four different resistance training exercises to assess the optimal sampling frequency. Eight physically active participants performed sets of Squat Jumps, Countermovement Jumps, Squats and Bench Presses at a maximal lifting speed. A linear encoder was used to measure the instantaneous speed at a 200 Hz sampling rate. Subsequently, the power spectrum of the signal was computed by evaluating its Discrete Fourier Transform. The sampling frequency needed to reconstruct the signals with an error of less than 0.1% was f99.9 = 11.615 ± 2.680 Hz for the exercise exhibiting the largest bandwidth, with the absolute highest individual value being 17.467 Hz. There was no difference between sets in any of the exercises. Using the closest integer sampling frequency value (25 Hz) yielded a reconstruction of the signal up to 99.975 ± 0.025% of its total in the worst case. In conclusion, a sampling rate of 25 Hz or above is more than adequate to record raw speed data and compute power during resistance training exercises, even under the most extreme circumstances during explosive exercises. Higher sampling frequencies provide no increase in the recording precision and may instead have adverse effects on the overall data quality. 相似文献
The purpose of this study was to investigate the effects of interval aerobic training combined with strength exercise in the same training session on body composition, and glycaemic and lipid profile in obese rats. Sixteen lean Zucker rats and sixteen obese Zucker rats were randomly divided into exercise and sedentary subgroups (4 groups, n = 8). Exercise consisted of interval aerobic training combined with strength exercise in the same training session. The animals trained 60 min/day, 5 days/week for 8 weeks. Body composition, lipid and glycaemic profiles and inflammatory markers were assessed.
Results showed that fat mass was reduced in both lean and obese rats following the exercise training (effect size (95% confidence interval (CI)) = 1.8 (0.5–3.0)). Plasma low-density lipoprotein–cholesterol and fasting glucose were lower in the exercise compared to the sedentary groups (d = 2.0 (0.7–3.2) and 1.8 (0.5–3.0), respectively). Plasma insulin was reduced in exercise compared to sedentary groups (d = 2.1 (0.8–3.4)). Some exercise × phenotype interactions showed that the highest decreases in insulin, homeostatic model assessment-insulin resistance, fasting and postprandial glucose were observed in the obese + exercise group (all, P < 0.01). The findings of this study suggest that interval aerobic training combined with strength exercise would improve body composition, and lipid and glycaemic profiles, especially in obese rats. 相似文献
Assessing individuals as failures in education and training is rarely something that is done lightly or without misgivings. Related to this, the challenges of setting clear threshold or passing standards, are considerable. Assessors’ affective responses during fail scenarios in professional training were explored during focused interviews with 30 academic and practice staff. The pattern of feelings reported at each stage of the decision‐making process, factors which influence judgements and the reactions of others are described. The strength and spread of feelings stand out as an important sources of evidence. Understanding more about these affective responses may assist assessors as they make critical judgements at the margins of professional competence. 相似文献
There has been a threefold increase in the employment of casual academics in Australian universities within the last 20 years, to the extent that most teaching and marking is now undertaken by casual academics, also known as sessional staff. Yet, casualised teaching and assessment has been considered a risk to student engagement and success, and casual academics report a lack of professional development and increased feelings of marginalisation within the academy. Concurrently, the quality assurance of teaching and assessment in higher education has become a central focus of the government-funded regulatory organisation, the Tertiary Education Quality and Standards Agency (TEQSA). Situated within this context, we report on an assessment moderation process that could support casual academics’ contextualised professional development, generate a sense of connectedness and collegiality and fulfil the requirements of TEQSA. Such processes may ensure that workforce growth in the higher education system supports a robust quality assurance and regulatory framework. 相似文献
In this work, we presented an analysis of the representation of the special relativity theory (SRT) in the most used texts
in high school, Polimodal level and university level in the teaching in the Argentine Republic, from a historic, epistemological
and didactic perspective. The results show that none of the analyzed texts would allow a contextualized approach on such theory. 相似文献
In this paper we examine the possible explanations for the patterns of results found at Oxford, in which women students consistently achieve a lower proportion of both first and third class honours. Usual explanations that rest on socio‐biology or simple forms of socialisation are rejected in favour of an explanation which is based on the idea of a mutual determination of social structure and social being. Various hypotheses are proposed as possible explanations of the examination statistics. 相似文献
A framework for planning enrichment activities within a self‐contained classroom is described through the structure of Core‐Explore‐More. At the Core level, activities systematically introduce students to concepts, generalizations and basic skills related to an important curriculum theme. Explore activities allow follow‐up experiences for those students who have been excited and motivated by what they have done at the core level. More activities require greater commitment and individual student initiative because of their specialization. 相似文献