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) between the ball-carrier (4.6 ± 1 m · s^–1) and tackler (7.1 ± 3.5 m · s^–1) was found at the 0.5 s time to contact interval in the Varsity Cup. For side-on tackles, differences between the two opposing players were found at 0.5 s (ball-carrier: 4.6 ± 1.7 m · s^–1; tackler: 3.1 ± 1.2 m · s^–1) and 0.4 s (ball-carrier: 6.3 ± 2.3 m · s^–1; tackler: 3.7 ± 1.6 m · s^–1) at Under-19 level. After 0.4 s, no significant differences (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.     

Effects of key state policies on private colleges and universities: sustaining private-sector capacity in the face of the higher education access challenge

The relationship between key state policy variables — (1) relative (private–public) tuition prices, (2) state student-aid funding, and (3) public institution density — and the competitive position of private colleges and universities is examined. Elite private schools are found to be nearly impervious to state policy. Large and moderately selective private institutions are adversely affected by public institution density and low public prices. Such prices divert students who would otherwise prefer these private institutions to similar public schools. State student aid funding most affects the enrollment market shares of the small, low-selectivity private colleges enrolling the greatest proportions of minority and modest-income students. The findings suggest state policies in this era of strong demand for higher education and constrained public sector capacity should use price signals (student aid and public institution pricing) to encourage students to consider seriously whether private higher education might serve their needs as well as or better than public institutions.     

A directory of European scholars in the speech field

The following directory was prepared with the expectation that it would facilitate communication between Speech scholars in the United States and those of other lands.     

An undergraduate course to bridge the gap between textbooks and scientific research

This article reports on a one-semester Advanced Cell Biology course that endeavors to bridge the gap between gaining basic textbook knowledge about cell biology and learning to think and work as a researcher. The key elements of this course are 1) learning to work with primary articles in order to get acquainted with the field of choice, to learn scientific reasoning, and to identify gaps in our current knowledge that represent opportunities for further research; 2) formulating a research project with fellow students; 3) gaining thorough knowledge of relevant methodology and technologies used within the field of cell biology; 4) developing cooperation and leadership skills; and 5) presenting and defending research projects before a jury of experts. The course activities were student centered and focused on designing a genuine research program. Our 5-yr experience with this course demonstrates that 1) undergraduate students are capable of delivering high-quality research designs that meet professional standards, and 2) the authenticity of the learning environment in this course strongly engages students to become self-directed and critical thinkers. We hope to provide colleagues with an example of a course that encourages and stimulates students to develop essential research thinking skills.     

A SURVEY OF TYPICAL CHURCH BIBLE CLASSES FOR BOYS AND MEN

Emerging social media that build on digital technologies are reshaping how we interact with each other. Religious education and identity formation within these new cultural flows demands recognition of the shifts in authority, authenticity, and agency that are taking place, as well as the challenges posed by “context collapse.” Digital storytelling is one mechanism by which religious educators can help people to apprentice into practices shaped by a commitment to human freedom and relationality, rather than to public performances of hatred.     

Nothing about us without us! Youth-led solutions to improve high school completion rates

This Youth Participatory Action Research (YPAR) study represents a collaboration with six students from alternative education to inquire about the experiences of vulnerable youth – students in alternative education and youth who have dropped out of school. Utilizing the Enhanced Critical Incident Technique, youth researchers asked their peers what helped and hindered their retention and success in mainstream and alternative education. Youth researchers engaged in authentic participation and took part in the iterative phases of YPAR – critical reflection and social action. Their involvement empowered them to advocate for their peers by disseminating the results and recommendations to key stakeholders within the community. Youth researchers conducted semi-structured interviews with 18 participants. Overall, the findings show that relationships with staff and peers, flexibility, psychosocial and academic supports, and personal circumstances are vital in helping vulnerable students succeed in school. Engagement in YPAR provided insight into working with vulnerable youth in a manner that promotes agency and social change within educational institutions.