First‐year Biology Students’ Understandings of Meiosis: An investigation using a structural theoretical framework

Meiosis is a biological concept that is both complex and important for students to learn. This study aims to explore first‐year biology students’ explanations of the process of meiosis, using an explicit theoretical framework provided by the Structure of the Observed Learning Outcome (SOLO) model. The research was based on responses of 334 first‐year biology students to practical and examination questions about meiosis, together with student interviews. Students’ written responses were coded, which resulted in a hierarchy of qualitatively different categories consistent with recent developments in the SOLO model. Most responses described a number of the less abstract elements of meiosis, but not in a coherent, relational manner, and interviews elucidated several areas of confusion about meiosis and its subordinate concepts. These findings are consistent with much previous research, and provide insights into both the use of the SOLO model as a research tool and students’ understandings of meiosis. In conjunction with previous research, the results of this study raise questions beyond its local context about the match between students’ apparent understandings and university expectations. The implications of the study relate to the use of terminology, the treatment of meiosis in textbooks, and some specific issues of pedagogy.     

A Study of Children’s Fears

In carefully examining the thesis of a paper by Anderson, Nelson, and Edgington (1984) concerning the socalled Fool’s Type IIa error, one realizes that certain fundamental statistical tenets have been overlooked or ignored. The purpose of the present paper is to discount the notion of a Fool’s Type IIa error under the Neyman-Pearson philosophy of testing statistical hypotheses and to highlight the need for improved statistical education related to hypothesis testing. If the importance of Type I and Type II errors cannot be quantified, then the Neyman-Pearson approach to hypothesis testing is of no value, and hence a Fool’s Type IIa error is irrelevant. If statistical testing errors are important and can be quantified, then adjustment for the Fool’s Type IIa error region is equivalent to increasing the probability of making a Type I error.     

Intensity of Treadmill Training and its Effect on Body Composition in Rats

Abstract

The purpose of this study was to determine which of three intensities of treadmill training produced changes in body composition in rats as evidenced by body weight, percentage of fat and specific gravity. Subjects were 60 male Wistar rats 25 to 30 days old when obtained. They were randomly assigned to one of five groups: sedentary controls, spontaneously active controls, and three groups of rats forced to exercise on a treadmill at intensities of 75, 125 and 175 fpm. Forced exercise was applied three times a week for 8 weeks, after which measures of body weight, specific gravity, and percentage of body fat were obtained. Results indicated that the sedentary controls had significantly higher mean body weights than did those which exercised. Rats forced to exercise at 75 fpm had significantly lower specific gravity measures than rats trained at 125 fpm. Sedentary controls had lower specific gravity values than did all rats allowed to exercise. Intensity of treadmill training had no effect on percentage of body fat as determined chemically. However, exercise was effective in reduction of body fat.     

The influence of carbohydrate and protein ingestion during recovery from prolonged exercise on subsequent endurance performance

Abstract

Ingesting carbohydrate plus protein following prolonged exercise may restore exercise capacity more effectively than ingestion of carbohydrate alone. The objective of the present study was to determine whether this potential benefit is a consequence of the protein fraction per se or simply due to the additional energy it provides. Six active males participated in three trials, each involving a 90-min treadmill run at 70% maximal oxygen uptake (run 1) followed by a 4-h recovery. At 30-min intervals during recovery, participants ingested solutions containing: (1) 0.8 g carbohydrate · kg body mass (BM)^?1 · h^?1 plus 0.3 g · kg^?1 · h^?1 of whey protein isolate (CHO-PRO); (2) 0.8 g carbohydrate · kg BM^?1 · h^?1 (CHO); or (3) 1.1 g carbohydrate · kg BM^?1 · h^?1 (CHO-CHO). The latter two solutions matched the CHO-PRO solution for carbohydrate and for energy, respectively. Following recovery, participants ran to exhaustion at 70% maximal oxygen uptake (run 2). Exercise capacity during run 2 was greater following ingestion of CHO-PRO and CHO-CHO than following ingestion of CHO (P ≤ 0.05) with no significant difference between the CHO-PRO and CHO-CHO treatments. In conclusion, increasing the energy content of these recovery solutions extended run time to exhaustion, irrespective of whether the additional energy originated from sucrose or whey protein isolate.     

The Decline of Women Leaders (Coaches and Athletic Directors) in Girls' Interscholastic Sport Programs in Virginia from 1972 to 1987

Abstract

The purpose of this study was to determine if static and baltislic stretching would, induce significant amounts of delayed onset muscle soreness (DOMS) and increases in creatine kinase (CK). Twenty males were randomly assigned to a static (STATIC) or ballistic stretching (BALLISTIC) group. All performed three sets of 17 stretches during a 90-min period, the only group difference being that STATIC remained, stationary during each 60-s stretch while BALLISTIC performed, boundng movements. Subjective ratings of DOMS (scale: 1–10) and serum CK levels were assessed before and every 24 hours post stretching, for 5 days. A repeated measures ANOVA revealed a significant main effect due to time (p < .05), with peak soreness occurring at 24 hours after (M = 2.8 ? 1.6). Surprisingly, a group effect (p < .05) demonstrated. that DOMS was significantly greater for STATIC than for BALLISTIC. At 24 hours there was a 62% (p < .05) increase in CK for combined groups. These findings indicate that similar bouts of static and ballistic stretching induce significant increases in DOMS and CK in subjects unaccustomed to such exercise. Furthermore, static stretching induced significantly more DOMS than did ballistic.     

Factors Related to Rural Young Adolescents' Participation in Outdoor,Noncompetitive Physical Activity

Purpose: Young adolescents who have little interest in participating in competitive team sports are at an increased risk for physical inactivity. Noncompetitive outdoor physical activity can provide young adolescents with increased opportunities to participate in physical activities that appeal to them and have positive health effects. The purpose of this study was to examine factors related to rural young adolescents' participation in noncompetitive outdoor physical activity to inform intervention design. Method: Young adolescents aged 10 to 14 years old (N = 1,032) from 1 rural county completed a self-administered questionnaire assessing constructs from self-determination theory (SDT) and the theory of planned behavior (TPB) related to noncompetitive outdoor physical activity. Structural equation modeling was used to examine an integrated conceptual model of hypothesized relationships among constructs. Results: The hypothesized conceptual model provided a good fit to the data with greater perceptions of autonomy support and self-determined motivation having statistically significant positive indirect effects on participation in noncompetitive outdoor physical activity mediated by the constructs of the TPB. All direct paths in the model were statistically significant; however, the direct effect of attitudes on intention was weak (.08) and self-determined motivation had no indirect effect on intention through attitudes (.03). Conclusions: Constructs of SDT and TPB should be accounted for by interventions targeting noncompetitive outdoor physical activity among young adolescents. More research is needed to determine young adolescents' preferences for noncompetitive and competitive physical activity and the potential influence that noncompetitive outdoor physical activity may have on total daily physical activity.