Measuring systematic long-term trajectories of school effectiveness improvement

The objective of this study was to identify trajectories of school improvement experienced by Chilean elementary schools over the last decade. Using econometric analysis and controlling for potential confounding factors, we created an index of school performance combining outcome indicators focused on different school dimensions, and estimated the 2002/2010 evolution of school improvement for all Chilean schools with available data. Broadly, we estimated an average increase in the school performance of about 0.19 SD; nevertheless, while 41% of the schools increased their educational performance by at least 0.1 SD, 25% of the schools decreased it during the same period; we also found that improving school effectiveness was more probable among schools with lower student socioeconomic status (SES). Finally, we found that the observed school improvement trajectories tended to be non-linear; thus, we estimated that only 13.4% of the schools improved their performance in a systematic way during the entire decade.     

Time-course of running treadmill adaptation in novice treadmill runners

ABSTRACT

Studies on running biomechanics and energetics are usually conducted on a treadmill. To ensure that locomotion on a treadmill is comparable to locomotion overground, participants need to be expert in the use of the device. This study aimed to identify the number and duration of sessions needed to obtain stable measurements for spatiotemporal and metabolic parameters in unexperienced treadmill runners. Fourteen male recreational runners performed three 15-min treadmill running trials in different days at a submaximal speed. Spatiotemporal and metabolic parameters were registered at minutes: 5, 10, 15 and their within-trial and between-trial changes were analysed using a two-way repeated measures ANOVA and Bonferroni post-hoc test. Within-trial differences were found in step frequency (decreased over time), Step Length and Contact Time (increased), reaching stability at different time points. Ventilator parameters increased, reaching stability after 5–10 min, while heart rate increased progressively over time. The only between-trial differences were an increase in step length and a decrease in step frequency at min 1, between trials 1 and 3. In conclusion, at least three running trials of 15 min are required to familiarize with the device. The last 5 min of the third trial can be regarded as stable measurements.     

Quantitative evaluation of alternative field normalization procedures

Wide differences in publication and citation practices make impossible the direct comparison of raw citation counts across scientific disciplines. Recent research has studied new and traditional normalization procedures aimed at suppressing as much as possible these disproportions in citation numbers among scientific domains. Using the recently introduced IDCP (Inequality due to Differences in Citation Practices) method, this paper rigorously tests the performance of six cited-side normalization procedures based on the Thomson Reuters classification system consisting of 172 sub-fields. We use six yearly datasets from 1980 to 2004, with widely varying citation windows from the publication year to May 2011. The main findings are the following three. Firstly, as observed in previous research, within each year the shapes of sub-field citation distributions are strikingly similar. This paves the way for several normalization procedures to perform reasonably well in reducing the effect on citation inequality of differences in citation practices. Secondly, independently of the year of publication and the length of the citation window, the effect of such differences represents about 13% of total citation inequality. Thirdly, a recently introduced two-parameter normalization scheme outperforms the other normalization procedures over the entire period, reducing citation disproportions to a level very close to the minimum achievable given the data and the classification system. However, the traditional procedure of using sub-field mean citations as normalization factors yields also good results.     

Little Evidence That Time in Child Care Causes Externalizing Problems During Early Childhood in Norway

Associations between maternal reports of hours in child care and children's externalizing problems at 18 and 36 months of age were examined in a population‐based Norwegian sample (n = 75,271). Within a sociopolitical context of homogenously high‐quality child care, there was little evidence that high quantity of care causes externalizing problems. Using conventional approaches to handling selection bias and listwise deletion for substantial attrition in this sample, more hours in care predicted higher problem levels, yet with small effect sizes. The finding, however, was not robust to using multiple imputation for missing values. Moreover, when sibling and individual fixed‐effects models for handling selection bias were used, no relation between hours and problems was evident.     

‘I'm your teacher,I'm Brazilian!’ Authenticity and authority in European capoeira

Capoeira, the Brazilian dance and martial art is now globalised and taught widely outside Brazil. Instruction is provided by Brazilians who are living in self-imposed exile from their homeland. The authentic capoeira that such teachers provide is a major attraction for non-Brazilian students. However, there is little research available on the motivations and strategies of overseas capoeira instructors. Building on a long term ethnographic study, this paper showcases the goals and strategies of one successful Brazilian teacher, from the Beribazu Group of Capoeira, working in the UK. This teacher reflects upon his four interlocking aims for his students and the strategies for achieving them. They should develop social cohesion, appreciate Brazilian culture, play good capoeira and learn to move their bodies acrobatically, flexibly and beautifully. Two sociologists embed the teacher's perspective on his work in an analytic framework derived from Bourdieu.     

The acute effects of static stretching on peak force,peak rate of force development and muscle activity during single- and multiple-joint actions in older women

Abstract

The present study investigated the acute effects of static stretching on peak force, peak rate of force development and integrated electromyography (iEMG) in 27 older women (65 ± 4 years; 69 ± 9 kg; 157 ± 1 cm; 28 ± 4 kg · m^?2). The participants were tested during two exercises (leg press and knee extension) after two conditions: stretching and control. The data were collected on four days (counterbalanced with a 24-hour rest period). In the stretching condition, the quadriceps muscle was stretched (knee flexion) for three sets of 30 s with 30 s rest intervals. No significant difference was detected for peak force and peak rate of force development during the single- and multiple-joint exercises, regardless of the following interactions: condition (stretching and control) vs. time (pre x post x 10 x 20 x 30 minutes post; P > 0.05) and exercise vs. time (P > 0.05). Additionally, no significant interaction was found for the iEMG activity (condition vs. time; P > 0.05) in the single- and multiple-joint exercises. In conclusion, a small amount of stretching of an agonist muscle (quadriceps) did not affect the peak force, peak rate of force development and EMG activity in older women during single- and multiple-joint exercises.     

The links between students’ relationships with teachers,likeability among peers,and bullying victimization: the intervening role of teacher responsiveness

Highly responsive teachers tend to foster behaviors that are low in conflict and high in prosociality, among their students, leading to a positive classroom climate and to a decrease in bullying victimization. However, little is known about the interaction between teacher responsiveness and both student–teacher, and student–student relationship characteristics, in influencing students’ bullying victimization at school. Here, we examined student–teacher relationship quality and students’ likeability among peers as predictors of in-school victimization. Additionally, we investigated the moderating role of teacher responsiveness over this link. Study sample consisted of 386 early-adolescent students (55.2% female, mean age [SD] = 12.17 [0.73]) and 19 main teachers (females, n = 14). Findings indicated that students’ exposure to victimization was positively associated with student–teacher conflict and negatively associated with likeability among classroom peers. Teacher responsiveness did not show a significant direct association with bullying victimization. However, when teachers showed high responsiveness, the strength of the association between student–teacher conflict and students’ likelihood of bullying victimization was slightly increased. The present study highlights the importance of considering the role of teacher responsiveness when modeling the link between student and teacher relationship quality and in school bullying victimization.

     

Does daddy know best? Exploring the relationship between paternal sexual communication and safe sex practices among African-American women

Parental sexual risk communication may influence women's sexual decision-making and safe sexual behaviours. While many studies have focused specifically on the influence of communication from mothers, some authors have argued for the importance of examining father–daughter sexual risk communication as well. However, few studies have empirically examined this relationship among African-American women. The present study sought to expand the literature by examining the relationship between various sexual risk messages received from paternal caregivers and the safe sexual practices of a sample of 171 African-American women from the Midwest USA. Results suggested that receiving messages from paternal caregivers cautioning participants about the intentions of men in romantic relationships was related to an increased likelihood of participants asking intimate partners about their sexual history. However, these messages were inversely related to safer condom practices. Implications for future research and clinical practice are discussed.     

The Effects of Vertical Integration on the Release of New Films

This article both theoretically and empirically addresses how a vertical structure in the motion pictures industry determines the number of prints a distributor releases of a new film. A simple theoretical model shows that the optimal number of copies is increasing on the expected demand for the film and the revenue share of the distributor and decreasing on the cost of each copy. The model also predicts that the optimal number of copies will decrease with the number of theaters that are vertically integrated with the distributor, as long as running a cinema requires financing a non-negligible cost of capital. The theoretical results are empirically tested using a very rich dataset of films' exhibition patterns in the major Chilean markets. The empirical results show that, on average, a non-integrated distributor releases 8 more copies than an integrated distributor.