Gunshot entrance wound abrasion ring width as a function of projectile diameter and velocity

The relationships between gunshot entrance wound abrasion ring widths versus projectile diameter and velocity, using foam-backed deer hides as targets, were investigated. At a fixed velocity, abrasion ring width increased with increasing projectile diameter but decreased in proportion to the central defect diameter. For fixed-diameter projectiles, very slow and high velocities produced minimal abrasion width. Maximal abrasion width occurred at intermediate velocities. The authors postulate that abrasion width is a function of the ratio of projectile velocity and the maximum deformation velocity of the target skin. The largest abrasion width occurs when the ratio is one. Using a projectile velocity known to produce maximum abrasion width at an initial warm temperature, then decreasing the target deformation velocity by cooling, produced the expected results of decreasing abrasion width.     

Mathematics anxiety among talented students

In order to test the assumption that mathematically talented students show little mathematics anxiety, students participating in an early entrance to college program for talented students were asked to complete the Mathematics Anxiety Rating Scale. Results indicated that these talented students were less math anxious than most unselected college students. However, they were more math anxious than a group of college students majoring in physics. Females in the study showed a tendency to be more math anxious than males (d=–.32), although this finding was not significant. No relationship between level of mathematics anxiety and grades or math anxiety and Scholastic Aptitude Test — Mathematics scores was found for the group of subjects. However, when those relationships were examined for males alone, higher verbal scores and higher grades were associated with lower levels of mathematics anxiety. These relationships were not evident for females.Received Ph.D. in educational psychology from Texas A&M University, and was Postdoctoral Fellow with the Study of Mathematically Precocious Youth at Johns Hopkins University. Research interests include studying characteristics of mathematically talented students and developing appropriate programs for them.Ph.D. in educational psychology from Southern Illinois University. Research interests include measurement and evaluation.