Wearable inertial sensors in swimming motion analysis: a systematic review

The use of contemporary technology is widely recognised as a key tool for enhancing competitive performance in swimming. Video analysis is traditionally used by coaches to acquire reliable biomechanical data about swimming performance; however, this approach requires a huge computational effort, thus introducing a delay in providing quantitative information. Inertial and magnetic sensors, including accelerometers, gyroscopes and magnetometers, have been recently introduced to assess the biomechanics of swimming performance. Research in this field has attracted a great deal of interest in the last decade due to the gradual improvement of the performance of sensors and the decreasing cost of miniaturised wearable devices. With the aim of describing the state of the art of current developments in this area, a systematic review of the existing methods was performed using the following databases: PubMed, ISI Web of Knowledge, IEEE Xplore, Google Scholar, Scopus and Science Direct. Twenty-seven articles published in indexed journals and conference proceedings, focusing on the biomechanical analysis of swimming by means of inertial sensors were reviewed. The articles were categorised according to sensor’s specification, anatomical sites where the sensors were attached, experimental design and applications for the analysis of swimming performance. Results indicate that inertial sensors are reliable tools for swimming biomechanical analyses.     

Effects of changing speed on knee and ankle joint load during walking and running

Joint moments can be used as an indicator of joint loading and have potential application for sports performance and injury prevention. The effects of changing walking and running speeds on joint moments for the different planes of motion still are debatable. Here, we compared knee and ankle moments during walking and running at different speeds. Data were collected from 11 recreational male runners to determine knee and ankle joint moments during different conditions. Conditions include walking at a comfortable speed (self-selected pacing), fast walking (fastest speed possible), slow running (speed corresponding to 30% slower than running) and running (at 4 m · s^?1 ± 10%). A different joint moment pattern was observed between walking and running. We observed a general increase in joint load for sagittal and frontal planes as speed increased, while the effects of speed were not clear in the transverse plane moments. Although differences tend to be more pronounced when gait changed from walking to running, the peak moments, in general, increased when speed increased from comfortable walking to fast walking and from slow running to running mainly in the sagittal and frontal planes. Knee flexion moment was higher in walking than in running due to larger knee extension. Results suggest caution when recommending walking over running in an attempt to reduce knee joint loading. The different effects of speed increments during walking and running should be considered with regard to the prevention of injuries and for rehabilitation purposes.     

Priming and Fake News: The Effects of Elite Discourse on Evaluations of News Media

Fake news has become a prominent topic of public discussion, particularly among elites. Recent research has explored the prevalence of fake news during the 2016 election cycle and possible effects on electoral outcomes. This scholarship has not yet considered how elite discourse surrounding fake news may influence individual perceptions of real news. Through an experiment, this study explores the effects of elite discourse about fake news on the public’s evaluation of news media. Results show that exposure to elite discourse about fake news leads to lower levels of trust in media and less accurate identification of real news. Therefore, frequent discussion of fake news may affect whether individuals trust news media and the standards with which they evaluate it. This discourse may also prompt the dissemination of false information, particularly when fake news is discussed by elites without context and caution.     

Modeling Growth in Electronic Learning Environments Using a Longitudinal Random Item Response Model

In educational environments, monitoring persons' progress over time may help teachers to evaluate the effectiveness of their teaching procedures. Electronic learning environments are increasingly being used as part of formal education and resulting datasets can be used to understand and to improve the environment. This study presents longitudinal models based on the item response theory (IRT) for measuring persons' ability within and between study sessions in data from web-based learning environments. Two empirical examples are used to illustrate the presented models. Results show that by incorporating time spent within- and between-study sessions into an IRT model; one is able to track changes in ability of a population of persons or for groups of persons at any time of the learning process.     

Estimation of a Nonlinear Intervention Phase Trajectory for Multiple-Baseline Design Data

A multilevel logistic model for estimating a nonlinear trajectory in a multiple-baseline design is introduced. The model is applied to data from a real multiple-baseline design study to demonstrate interpretation of relevant parameters. A simple change-in-levels (ΔLevels) model and a model involving a quadratic function (Quadratic) for the nonlinear intervention phase data were also estimated. In addition, a simulation study was conducted to assess Markov chain Monte Carlo estimation of the logistic model and compare its trajectory recovery with use of the ΔLevels and Quadratic models. While most of the logistic model's parameter values were recovered well, trajectory recovery was very reasonable using the simpler Quadratic model. Results are discussed along with recommendations for practitioners and directions for future research.     

Social capital in the classroom: a study of in-class social capital and school adjustment

Social capital is generally considered beneficial for students’ school adjustment. This paper argues that social relationships among pupils generate social capital at both the individual and the class levels, and that each has its unique effect on pupils’ performance and well-being. The sample in this study consists of 1036 children in 60 first-grade classes in 46 Dutch elementary schools. Multilevel regression results show that a substantial proportion of the variance in school adjustment can be attributed to the class level and that both individual-level and classroom-level social capital have substantial effects on school adjustment. At the individual level, the size of one’s network is more important than its structure. At the collective level, social capital also has a ‘dark side’ because it can have negative effects on adjustment, lowering the academic performance in a class.     

Phonological Processing and Word Reading in Typically Developing and Reading Disabled Children: Severity Matters

In this study word reading (WR) fluency was used to dichotomously classify 1,598 Dutch children at different cutoffs, indicating (very) poor or (very) good reading performance. Analysis of variance and receiver operating characteristics were used to investigate the effects of rapid automatized naming (RAN) and phonemic awareness (PA) in predicting group membership. The highest predictive values were found for the combination of RAN and PA, particularly for the poorest readers. Furthermore, results indicate that with the severity of impairment, WR is more dominated by deficient PA, which is interpreted as an enduring problem with sublexical processing. Another main result is that with the increase of reading skill, the contribution of PA diminishes, whereas the contribution of RAN remains fairly constant for the whole reading fluency continuum. These results warrant the conclusion that whereas PA hallmarks reading disability, RAN appears to be the default predictor for above-average or excellent reading proficiency.     

Reconceptualizing student ratings of teaching to support quality discourse on student learning: a systems perspective

Higher Education - This paper summarizes the discourse on student ratings of teaching in higher education. It reconceptualizes student ratings within a larger process of promoting quality in...