Strategies to improve impact efficiency in football kicking

In football, kicking with high ball velocity can increase scoring opportunities and reduce the likelihood of interception. Efficient energy transfer from foot to ball during impact is important to attain a high ball velocity. It is considered impact efficiency can be increased by reducing the change in ankle plantarflexion during foot–ball impact. However, conflicting evidence exists, questioning its effectiveness as a coaching cue. The aim of the present study was to systematically analyse joint stiffness, foot velocity and impact location with a mechanical kicking machine to determine if change in ankle plantarflexion during foot–ball impact and ball velocity are influenced. Sagittal plane data of the shank, foot and ball were measured using high-speed video (4,000 Hz). Increasing joint stiffness reduced change in ankle plantarflexion and increased ball velocity from a greater effective mass. Increasing foot velocity increased change in ankle plantarflexion and increased ball velocity. Distal impact locations increased change in ankle plantarflexion and reduced ball velocity as coefficient of restitution decreased. These results identify that change in ankle plantarflexion is a dependent variable during foot–ball impact and does not directly influence ball velocity. Coaches can assess ankle motion during impact to provide feedback to athletes on their impact efficiency.     

Foot and ankle joint movements of dancers and non-dancers: a comparative study

Ballerinas use their ankle joints more extremely and sustain injuries on the ankle joint more frequently than non-dancers. Therefore, the ankle movement of dancers is important and should be studied to prevent injuries. Measuring ankle joint range of motion (ROM) using radiographs could demonstrate the contribution to motion of each joint. The aim of this study was to analyse and compare ankle joint movements and the ratio of each joint’s contribution during movement between dancers and non-dancers, using radiographic images. Dancers have lower dorsiflexion (26.7 ± 6.2°), higher plantarflexion (74.3 ± 7.1°) and higher total (101.1 ± 10.8°) ROMs than non-dancers (33.9 ± 7.0°, 57.2 ± 6.8° and 91.1 ± 9.3°, respectively) (p < 0.05). Although the ROMs were different between the two groups, the ratios of each joint movement were similar between these two groups, in all movements. Regarding total movement, the movement ratio of the talocrural joint was almost 70% and other joints accounted for almost 30% of the movement role in both dancers and non-dancers. Therefore, the differences in ROM between dancers and non-dancers were not a result of a specific joint movement but of all the relevant joints’ collaborative movement.     

Reading and Related Skills in the Early School Years: Are boys really more likely to struggle?

This study examined whether boys and girls in the early school years differed in reading and related skills, and their rates of progress. Gender ratios were calculated to ascertain whether there were more boys than girls who struggle with different facets of reading, and whether the variability of boys’ scores resulted in more boys being identified as poor readers, as evidenced by previous studies. A sample of 335 students in Years 1 and 2 were administered six reading and related assessments. Boys and girls did not significantly differ on any of the measures, and differences in gains were negligible. Boys did not consistently demonstrate significantly greater variability in scores (with the exception of single-word reading and spelling in Year 1 only). These differences, however, did not affect gender ratios for poor performance. Gender ratios were relatively low across measures, but increased with years of schooling. Implications of the results are discussed.     

The utility of general and school-specific personality traits and an examination of their relationship over time

A university student sample was used to compare school-specific (i.e., personality at school) and general personality (i.e., personality across all life domains) over eight weeks. School-specific and general personality incrementally predicted change in school-specific criteria (i.e., school satisfaction and school citizenship behaviors). Less consistent results were found for general criteria. Specifically, school-specific and general personality incrementally predicted change in general mental health, but failed to incrementally predict change in life satisfaction. In addition, we examined the school-specific–general personality relationship over time. Contrary to expectations, a unidirectional relationship was found in which school-specific personality predicted change in general personality, but general personality did not predict change in school-specific personality. Theoretical and practical implications are discussed.     

The role of affective and motivational factors in designing personalized learning environments

In this paper, guidelines for designing virtual change agents (VCAs) are proposed to support students?? affective and motivational needs in order to promote personalized learning in online remedial mathematics courses. Automated, dynamic, and personalized support is emphasized in the guidelines through maximizing interactions between VCAs and individual students. The strategies that VCAs convey throughout the interactions are constructed to support emotion regulation and motivation based on theories and prior research on emotions and motivation. The availability and customizability of VCAs enable the strategies to be implemented in real-time and customized for individual students. Implications of the design guidelines for personalized, online learning contexts are discussed and future research directions are recommended as well.     

The relations among L1 (Spanish) literacy skills,L2 (English) language,L2 text reading fluency,and L2 reading comprehension for Spanish-speaking ELL first grade students

We investigated the relations of L2 (i.e., English) oral reading fluency, silent reading fluency, word reading automaticity, oral language skills, and L1 literacy skills (i.e., Spanish) to L2 reading comprehension for Spanish-speaking English language learners in the first grade (N = 150). An analysis was conducted for the entire sample as well as for skilled and less skilled word readers. Results showed that word reading automaticity was strongly related to oral and silent reading fluency, but oral language skill was not. This was the case not only for the entire sample but also for subsamples of skilled and less skilled word readers, which is a discrepant finding from a study with English-only children (Kim et al., 2011). With regard to the relations among L2 oral language, text reading fluency, word reading automaticity, reading comprehension, and L1 literacy skills, patterns of relations were similar for skilled versus less skilled word readers with oral reading fluency, but different with silent reading fluency. When oral and silent reading fluency were in the model simultaneously, oral reading fluency, but not silent reading fluency, was uniquely related to reading comprehension. Children's L1 literacy skill was not uniquely related to reading comprehension after accounting for other L2 language and literacy skills. These results are discussed in light of a developmental theory of text reading fluency.     

Fachdidaktisches Wissen von Lehrkräften und multiple Ziele im naturwissenschaftlichen Sachunterricht

Recent investigations in the field of mathematics have demonstrated that teachers’ pedagogical content knowledge, as a central component of teachers’ professional knowledge, plays a significant role in high-quality instruction and students’ learning gains. The study presented here explores the significance of teachers’ pedagogical content knowledge for gains in pupils’ understanding of scientific concepts and for motivational and self-related outcome criteria in primary science education in Germany. It reports on findings from a study with a pre-post-design comprising 60 primary school teachers and their 1326 pupils. Teachers’ pedagogical content knowledge and pupils’ learning gains as well as motivational and self-related outcome criteria were directly assessed with paper-and-pencil tests. Two-step models controlling for several relevant variables at the individual and the class level were specified. Results revealed a substantial positive effect of the measured pedagogical content knowledge on pupils’ achievement gains as well as on pupils’ situational interest and perceived competence.     

The Impact of CMS Quality on the Outcomes of E‐learning Systems in Higher Education: An Empirical Study

Course Management Systems (CMSs) in higher education have emerged as one of the most widely adopted e‐learning platforms. This study examines the success of e‐learning CMSs based on user satisfaction and benefits. Using DeLone and McLean's information system success model as a theoretical framework, we analyze the success of e‐learning CMSs in five dimensions: system quality, information quality, instructional quality, user satisfaction, and CMS benefits. An analysis of survey data collected from students participating in a university‐wide CMS shows that system quality, information quality, and instructional quality positively influence user satisfaction, which, in turn, increases the benefits of CMSs. By providing a comprehensive framework for the critical success factors in e‐learning CMSs and their causal relationships, this study provides practical implications for managing e‐learning courses and resources for a more flexible and effective CMS‐centered, e‐learning environment.     

STUDENTS’ UNDERSTANDING OF LARGE NUMBERS AS A KEY FACTOR IN THEIR UNDERSTANDING OF GEOLOGIC TIME

An understanding of geologic time is comprised of 2 facets. Events in Earth’s history can be placed in relative and absolute temporal succession on a vast timescale. Rates of geologic processes vary widely, and some occur over time periods well outside human experience. Several factors likely contribute to an understanding of geologic time, one of which is an individual’s ability to perceive the relative size of large time periods and to move multiplicatively through quantities that differ by many orders of magnitude. Thirty-five US students aged 13–24?years participated in task-based interviews to assess their understanding of large temporal periods. Fewer than half of the students performed well enough to indicate that their knowledge of large numbers was robust enough to enable them to understand processes in geologic time. Some students were confused about relationships between quantities in the thousands and millions, while others had difficulty showing proportional relationships among relatively small temporal units (up to 100?years). Students differed in their ability to perceive the entire scale upon which numbers were to be placed as well as broader problem-solving strategies. Spatial mapping of numbers was evident. Implications for future research are discussed.     

The Public Knowledge Project and Open Journal Systems: open source options for small publishers

This article provides an overview of the Public Knowledge Project (PKP) and its open source software development projects, with a particular focus on Open Journal Systems (OJS), an online journal publishing platform now used by over 11,500 journals around the world. OJS is just one of many examples of software and services that provide new and cost‐effective alternatives, especially for small scholarly societies and commercial publishers. The development of online publishing, open source software, and virtual communities are together opening up new opportunities for scholars, researchers, societies, small publishers, and librarians to reassert their independence and control over the publishing process, and provides a wider range of options than has ever existed before.