Forward acceleration of the centre of mass during ski skating calculated from force and motion capture data

The purpose of this paper was to present and evaluate a methodology to determine the contribution of bilateral leg and pole thrusts to forward acceleration of the centre of mass (COM) of cross-country skiers from multi-dimensional ground reaction forces and motion capture data. Nine highly skilled cross-country (XC) skiers performed leg skating and V2-alternate skating (V2A) under constant environmental conditions on snow, while ground reaction forces measured from ski bindings and poles and 3D motion with high-speed cameras were captured. COM acceleration determined from 3D motion analyses served as a reference and was compared to the results of the proposed methodology. The obtained values did not differ during the leg skating push-off, and force–time curves showed high similarity, with similarity coefficients (SC) >0.90 in the push-off and gliding phases. In V2A, leg and pole thrusts were shown to contribute 35.1 and 65.9% to the acceleration of the body, respectively. COM acceleration derived from ground reaction forces alone without considering the COM position overestimated the acceleration compared to data from motion analyses, with a mean difference of 17% (P < 0.05) during leg push-off, although the shapes of force–time curves were similar (SC = 0.93). The proposed methodology was shown to be appropriate for determining the acceleration of XC skiers during leg skating push-off from multi-dimensional ground reaction forces and the COM position. It was demonstrated that both the COM position and ground reaction forces are needed to find the source of acceleration.     

Activity-related typologies and longitudinal change in physical activity and sedentary time in children and adolescents: The UP&DOWN Study

Background: Children and adolescents can be distinguished by different typologies (clusters) of physical activity and sedentary behavior. How physical activity ...     

Finding a Better Person-Environment Fit in the Academic Deanship

Individuals seek a balance between the demands of their institutions and the dimensions that make up their personalities and determine their needs (Getzels & Guba, 1957). Academic deans are no exception. Indeed, the fit (or lack of it) between the work environment and the unique characteristics of individuals asked to function within a given setting helps determine whether they experience levels of stress that move them forward in their work or suffer debilitating stress that leads to excessive physical and mental strain. This article examines the fit between academic deans and their work environments in the U.S. and Australia as it relates to multiple role stress factors affecting deans.     

The effect of national culture on partner buyouts in cross-border biotechnology alliances

This study examines how national culture influences the likelihood and rate of buyouts among R&D equity alliances and joint ventures in the biotechnology industry. We hypothesize that the interaction of specific national culture attributes and cultural differences between alliance partners have an impact on: (1) the amount of endogenous uncertainty surrounding the potential integration of the target firm and (2) the marginal rate of learning in hierarchical versus collaborative governance. Applying a competing hazard model to a sample of 173 joint ventures and minority equity collaborations in the biotechnology industry, we found that investing firms from high power distance and high uncertainty avoidance countries are more likely to buy out their alliance partners. Furthermore, greater cultural distance between alliance partners increases the likelihood of partner buyout when investing firms are from high power distance countries.     

Dosuperior teachers employ systematic instructional planning procedures? A descriptive study

The purpose of this study was to examine the extent to which a group of superior elementary and secondary school teachers employed systematic instructional planning practices. The research method employed was a multicase design in which nine teachers (five secondary and four elementary) from a single school district were studied. Qualitative data in the form of written surveys and face-to-face interviews were collected and analyzed. Results revealed that most of the teachers' planning activities centered around six types of decisions. When the teachers' planning activities were compared with a systematic approach to instructional planning, the two approaches were found to be different in several important ways: the teachers did not place much emphasis on specifying objectives, creating objectives-based tests, or making other instructional decisions in light of objectives. Implications for teaching preservice teachers about systematic planning are discussed. The authors would like to thank the nine teachers who participated in this study, and Julia O'Brien, who helped to conduct it.     

The Effect of Stereoscopic Augmented Reality Visualization on Learning Anatomy and the Modifying Effect of Visual-Spatial Abilities: A Double-Center Randomized Controlled Trial

Monoscopically projected three-dimensional (3D) visualization technology may have significant disadvantages for students with lower visual-spatial abilities despite its overall effectiveness in teaching anatomy. Previous research suggests that stereopsis may facilitate a better comprehension of anatomical knowledge. This study evaluated the educational effectiveness of stereoscopic augmented reality (AR) visualization and the modifying effect of visual-spatial abilities on learning. In a double-center randomized controlled trial, first- and second-year (bio)medical undergraduates studied lower limb anatomy with stereoscopic 3D AR model (n = 20), monoscopic 3D desktop model (n = 20), or two-dimensional (2D) anatomical atlas (n = 18). Visual-spatial abilities were tested with Mental Rotation Test (MRT), Paper Folding Test (PFT), and Mechanical Reasoning (MR) Test. Anatomical knowledge was assessed by the validated 30-item paper posttest. The overall posttest scores in the stereoscopic 3D AR group (47.8%) were similar to those in the monoscopic 3D desktop group (38.5%; P = 0.240) and the 2D anatomical atlas group (50.9%; P = 1.00). When stratified by visual-spatial abilities test scores, students with lower MRT scores achieved higher posttest scores in the stereoscopic 3D AR group (49.2%) as compared to the monoscopic 3D desktop group (33.4%; P = 0.015) and similar to the scores in the 2D group (46.4%; P = 0.99). Participants with higher MRT scores performed equally well in all conditions. It is instrumental to consider an aptitude–treatment interaction caused by visual-spatial abilities when designing research into 3D learning. Further research is needed to identify contributing features and the most effective way of introducing this technology into current educational programs.     

Necessary but not Sufficient: reconceptualizing primary teacher education

Initial primary teacher education should be designed to cater for the socially, culturally and linguistically diverse populations found in schools. They rarely are. As a result they tend to promote social reproduction rather than social transformation. Using vignettes drawn from our work on the New South Wales Ministerial Advisory Council for the Quality of Teaching we demonstrate the need to re‐explore the fundamental purposes and goals of preparing teachers to meet the needs of all children in our primary schools. We propose a reconceptualization of teacher education around a cultural studies perspective as a productive way forward which would allow integration rather than compartmentalization of knowledge and which encourages a search for truth in which tolerance of ambiguity and uncertainty feature such that knowledge is understood as relative and fallible.