Influence of moderate intensity physical activity levels and gender on conditioned pain modulation

This study examined the potential influence of moderate intensity physical activity (PA) levels and gender on central pain modulation using conditioned pain modulation (CPM) in healthy men and women. Twenty four individuals (12 men and 12 women) who reported engaging in the moderate intensity PA for 150 min or more per week and 24 individuals (12 men and 12 women) who reported engaging in moderate intensity PA for 60 min or less per week completed a self-report PA questionnaire and a 7-day PA assessment using an accelerometer. Furthermore, the participants completed the CPM testing to evaluate the efficiency of central pain modulation. The active individuals scored higher on the PA questionnaire and spent more minutes for light, lifestyle, moderate and vigorous intensity PA than the less active individuals. The active men and women exhibited comparable magnitudes of CPM, and showed a greater magnitude of CPM when compared to their less active counterparts. However, these beneficial effects of higher dose moderate intensity PA disappeared when time spent for vigorous intensity PA was statistically controlled for. These results suggest that the higher dose moderate intensity PA does not add to the benefits from vigorous intensity PA to further improve central pain modulatory systems.     

Clifford代数与Minkowski平面几何

以Clifford代数为工具，讨论Minkowski平面的几何性质，指明应用Clifford代数在计算机上实现Minkowski几何研究的可行性。     

Dissociation of conditioned appetitive and consummatory sexual behavior: Satiation and extinction tests

Sexual responses were conditioned in male Japanese quail using the opportunity to copulate with a female as the unconditioned stimulus (US). The conditioned stimulus (CS) was a 3-D object made of a taxidermically prepared female quail head mounted on a terry-cloth body. Both appetitive conditioned responses (approach and proximity to the CS) and consummatory conditioned responses (mount and cloacal contact directed toward the CS) developed when 2-min presentations of the CS were followed immediately by the US, but not when the CS and US were separated by trace intervals of 10 or 20 min (Experiment 1). Postconditioning sexual satiation suppressed conditioned cloacal contact responses more than conditioned approach to the CS (Experiment 2), and “acute” extinction suppressed both conditioned mounting and conditioned cloacal contact responses more than conditioned approach to the CS (Experiment 3). These results demonstrate a functional dissociation between conditioned appetitive and consummatory responses and imply that the motivational and/or associative mechanisms underlying the two types of behavior are distinct.     

Differing levels of gender salience in preschool classrooms: effects on children's gender attitudes and intergroup bias

Developmental intergroup theory posits that when environments make social-group membership salient, children will be particularly likely to apply categorization processes to social groups, thereby increasing stereotypes and prejudices. To test the predicted impact of environmental gender salience, 3- to 5-year-old children (N = 57) completed gender attitude, intergroup bias, and personal preference measures at the beginning and end of a 2-week period during which teachers either did or did not make gender salient. Observations of peer play were also made at both times. After 2 weeks, children in the high- (but not low-) salience condition showed significantly increased gender stereotypes, less positive ratings of other-sex peers, and decreased play with other-sex peers. Children's own activity and occupational preferences, however, remained unaffected.     

The pitfalls and promises of special education practice.

It is imperative that special education enable children with disabilities to achieve at high levels. Problems of equity and pedagogical validity have hindered our efforts thus far, and many children of minority cultures are far overrepresented in classrooms for students with learning disabilities and mild mental retardation. Studies have shown the importance of culturally and linguistically inclusive programs and of heterogenous groupings, as well as more effective diagnostic, remedial, and assessment practices. This article discussed a model and basic principles for such techniques to ensure that the educational outcomes of all children are improved.     

Mass Media Production Guides

William Hawes' The Performer in Mass Media in Media Professions and in the Community (New York: Hastings House, 1978—$15.75/8.95)

Robert L. Hilliard, ed. Television Broadcasting: An Introduction (New York: Hastings House, 1978— $15.75/7.95)

Charles Bensinger's The Video Guide (Santa Barbara, Calif.: Video-Info Publications (P.O. Box 1507), 1977— $11.95, paper)

Mike Wolverton's And Now the News (Houston, Tex.: Gulf Publishing Co., 1977— $10.95)

The WAFL Book: A Guide to Film and Video in the Washington, D.C. Area (Washington Area Filmmakers League, P.O. Box 6475, Washington, D.C. 20009 —$5.45, including postage, paper)

David E. Fear's Technical Writing (New York: Random House, 1978—price not given, paper)     

Learning,Theories of Learning,and Units of Analysis in Research

Over the past decades research on learning has become more diverse and complex. The concern expressed by Alexander, Schallert, and Reynolds (2009 Alexander, P. A., Schallert, D. L. and Reynolds, R. E. 2009. What is learning anyway? A topographical perspective considered. Educational Psychologist, 44: 176–192. this issue[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]/this issue) is that this diversity of theoretical perspectives has resulted in a fragmentation that is destructive to the field. Although it is important to engage in explicit discussions of how learning is construed in different traditions, Alexander et al. do not give sufficient recognition to the significant epistemological and theoretical differences between traditions; differences that make them incompatible in important respects, for instance, with respect to their units of analysis. An acceptance of incompatibilities in perspectives is not necessarily a problem. In fact, such a situation may, if the debates are grounded in a mutual acceptance of the diverse manners in which knowing and learning may be theorized, give us a richer frame of reference from which to analyze learning in its various manifestations in complex societies.