Velocity and acceleration before contact in the tackle during rugby union matches

Abstract The velocity and acceleration at which the ball-carrier or tackler enters the tackle may contribute to winning the contest and prevailing injury free. Velocity and acceleration have been quantified in controlled settings, whereas in match-play it has been subjectively described. The purpose of this study was to determine the velocity and acceleration of the ball-carrier and tackler before contact during match-play in three competitions (Super 14, Varsity Cup, and Under-19 Currie Cup). Using a two-dimensional scaled version of the field, the velocity and acceleration of the ball-carrier and tackler were measured at every 0.1 s to contact for 0.5 s. For front-on tackles, a significant difference (P??0.05) were evident. Also, the ball-carrier's velocity over the 0.5 s was relatively stable compared with that of the tackler. Results suggest that tacklers adjust their velocity to reach a suitable relative velocity before making contact with the ball-carrier.     

Pediatric cochlear implantation: a qualitative study of parental decision-making processes in Flanders, Belgium

Factors contributing to parents' decision when they choose between cochlear implantation (CI) and traditional hearing aids for their child were examined. The subjects were children with severe/profound hearing loss, born 1999-2001, registered in the universal neonatal hearing screening program in the Flanders region of Belgium. Qualitative data collected retrospectively from parents were subjected to thematic content analysis. In their responses to professional advice, parents were segmented into 3 groups: (a) those whose primary considerations were the importance of oral language development and the relative potential of CI and traditional hearing aids; (b) those for whom alternative factors (e.g., medical risks, ethical issues) were paramount, even in the face of professional advocacy of CI; (c) those who followed professional advice against CI. The researchers conclude that care professionals should be sensitive to the impact of their advice and other factors in parental decision making.     

The Differential Impacts of Early Physical and Sexual Abuse and Internalizing Problems on Daytime Cortisol Rhythm in School-Aged Children

The impact of early physical and sexual abuse (EPA/SA) occurring in the first 5 years of life was investigated in relation to depressive and internalizing symptomatology and diurnal cortisol regulation. In a summer camp context, school-aged maltreated ( n  =   265) and nonmaltreated ( n  =   288) children provided morning and late afternoon saliva samples on 5 consecutive days. Child self-report and adult observer reports of child internalizing and depressive symptoms were obtained. Children experiencing EPA/SA and high depressive or internalizing symptoms uniquely exhibited an attenuated diurnal decrease in cortisol, indicative of neuroendocrine dysregulation. These results were specific to EPA/SA rather than later onset physical or sexual abuse or early occurring neglect or emotional maltreatment.     

Observational learning from animated models: effects of studying–practicing alternation and illusion of control on transfer

Animated models explicating how a problem is solved and why a particular method is chosen are expected to be effective learning tools for novices, especially when abstract cognitive processes or concepts are involved. Cognitive load theory was used to investigate how learners could be stimulated to engage in genuine learning activities. It was hypothesized that illusion of control would impede transfer performance compared to a condition without illusion of control. Moreover, we hypothesized that learners who first studied an animated model and then solved the same problem would perform better on transfer than learners who studied the same animated model twice or who first solved the problem and then studied the animated model. In a 2 × 3 factorial experiment (N = 90) with the factors illusion of control (yes vs. no) and instruction method (study–practice, practice–study, study–study) only the first hypothesis was confirmed. Implications for the design of animated models are discussed.     

Critical issues in supporting self-study

In this article, we focus on an analysis of critical issues in supporting teacher educators conducting a self-study. As data, we have used the digital logbooks written by the participating teacher educators, the outcomes of the interviews we held at the end of the support process, and of a follow-up questionnaire answered by the participating teacher educators six months later. We have found seven issues critical to enhancing the chances of self-studies being beneficial to the practice of teacher education as well as to the further development of a knowledge base for teacher education. In addition, our study points to four themes for further attention and research.     

Preservice teachers' views of the nature of science during a postbaccalaureate science teaching program

The goals of this study were to determine preservice science teachers' views of the nature of science and to describe the changes in those views that occur during a teacher education program. Fifteen students in a postbaccalaureate secondary science teaching program at a large university participated in this study. The participants' views of science were ascertained by an investigator-developed survey and a follow-up interview administered before and after the university's science teaching methods sequence. Before entering the teaching program, the participants had a contemporary (i.e., postpositivist) view of scientific theory, knowledge, and the role of a scientist and a traditional (i.e., empiricist or positivist) view of scientific method. Initially, there was an equal number of traditional, mixed, and contemporary views of the different aspects of science. After completing the methods sequence, the number of contemporary views doubled and the number of mixed views decreased by more than half. The number of participants with an overall contemporary view of science rose from 2 to 7. Since there was little direct instruction about the nature of science, it is possible to make positive changes in preservice teachers' views of the nature of science in a teaching program in which contemporary teaching strategies such as conceptual change and cooperative learning are taught. © 1997 John Wiley & Sons, Inc. J Res Sci Teach 34: 595–615, 1997.