Affective responses to an aerobic dance class: the impact of perceived performance

The current study tests the mastery hypothesis as an explanation for the affective benefits of acute exercise. Participants were 204 undergraduate women who were participating in self-selected aerobic dance classes. Following the class, participants were asked to rate their exercise performance on a 5-point, Likert-type scale. Affect questionnaires were completed prior to and at 5 and 20 min following the aerobic dance class. Results indicated an overall improvement in affect following exercise. Negative valenced subscales were unaffected by performance ratings. Both groups showed similar reductions in these states. There was, however, a significant Group x Time interaction for the positive valenced subscales. High-performance participants reported greater increase in these variables throughout recovery than did low-performance participants. These data support the mastery hypothesis as an explanation for the exercise-induced change in positive affective states.     

The cell's journey: from metaphorical to literal factory

The concept of the cell has been based on metaphor since its inception, and the history of cell theory has continued to rely on metaphor and analogy. In the nineteenth century, cells were most popularly conceived either as building stones or elementary autonomous organisms from which larger organisms are composed. With advances in physiology and the rise of modern biochemistry in the early twentieth century, the chemical factory or laboratory became the dominant metaphor for this biological unit. Today in the twenty-first century, the metaphorical imagery has become a reality, with cells acting as chemical factories for the synthesis of commercially valuable bio-products. The history of the cell shows how metaphors act as conceptual tools, with particular strengths for facilitating different sorts of questions and experimental techniques.     

GENDER DIFFERENCES IN ACHIEVEMENT IN A LARGE,NATIONALLY REPRESENTATIVE SAMPLE OF CHILDREN AND ADOLESCENTS

The purpose of this study was to investigate developmental gender differences in academic achievement areas, with the primary focus on writing, using the child and adolescent portion (ages 6–21 years) of the Kaufman Test of Educational Achievement—Second Edition, Brief Form, norming sample (N = 1,574). Path analytic models with gender, parent education, age, age², and gender‐by‐age moderation as predictors of reading, writing, and math were used to test for gender differences and for the influence of development on these differences. A small but consistent advantage was identified for females in reading. No gender differences were detected in math. The most important results of the present study pertain to a gender gap in writing in favor of females that increased as a function of age. Male students are at greater risk for writing failure than are females.