Physical activity and executive control: implications for increased cognitive health during older adulthood

Electrocortical and behavioral responses of low, moderate, and high physically active older adults were compared with a younger control group on neutral and incompatible conditions of a flankers task. Compared to younger adults, high and moderate active older adults exhibited increased event-related potentials component P3 amplitude for the incompatible condition at the frontal electrode site. For the neutral condition, only low active older adults exhibited decreased amplitude at the central-parietal site, compared to younger adults. P3 latency revealed the longest latencies for low active older adults, followed by moderate active, high active, and younger adults, respectively. Reaction time (RT) data revealed that younger adults exhibited faster RT compared to all three older groups. Results suggest that physical activity may improve executive control function in older adults by affecting the distribution of P3 amplitude, which has been related to memory and attentional processes, and by decreasing P3 latency, which relates to the speed of cognitive processing.     

议程设置理论与后大众媒体时代的民意研究

关于媒体与民意的理论大部分提出于 1 93 0到 1 980年之间 ,这是一个仅仅拥有传统信息选择方式的时代。麦库姆斯和肖 (1 972 )最初提出议程设置理论时 ,用北卡罗莱纳州的教堂山 (ChapelHill)社区作为研究对象 ,而现在那里的媒介使用情况也已经发生了巨变。当我们迎来议程设置理论提出 3 0周年的时候 ,教堂山的受众现在面临的信息选择令人惊叹。在 2 0世纪 90年代 ,肖提出 ,美国的大众媒介已经经历了“兴和衰”(riseandfall)。肖认为 ,大众媒体时代结束于 2 0世纪 80年代。议程设置研究是否能像之前的 3 0年那样 ,继续开展下去 ?当受众使用着上百个信息来源时 ,议程设置和民意研究会产生何种变化 ?这是本文将要回答的问题     

Optimizing segmental movement in the jumping header in soccer

This study looks at segmental movements in the jumping header from an optimization viewpoint. Investigations on the header so far have focused on head restriction in the movement but have not clarified how and to what extent body segments influence the performance of the skill. In the present study a biomechanical model was used to analyze the jumping header in simulated competition to give a clear picture of an optimized header. Skilled soccer players headed balls at speeds of 13 m x s(-1) the results indicated that the head moves as a free non-restricted segment in the jumping header and should be allowed to do so, even though much soccer literature says otherwise to prevent injuries. The arm movement showed individual characteristics and gave no general advantages in optimizing ball speed after impact in the header The movement of the legs was, on the other hand, the single most important factor in the skill. Therefore, coaches and players shouldfocus on developing muscle strength in the stomach, back and pelvis and should put no restrictions on head and arm movement to optimize the jumping header.     

ONIX: Is there a return on investment for all publishers?

Summary What will be the future of ONIX? Some argue that wider industry acceptance will lead to increased efficiencies in the transfer of book data, which will ultimately benefit book sales. ONIX still has to overcome many challenges: its implementation cost is high, whole-salers and aggregators are still using different spreadsheets and information sources. Furthermore, MS Excel as an alternative solution is widely available and accepted by the industry. Small publishers need more education and a straightforward demonstration of ONIX’s return on investment. An outreaching of the helping hand of professional organizations is strongly suggested to foster the adoption process among small players. It is the role of the AAP and BISG to get their memberships to think about what is good for all members as a whole throughout the industry. As an organization BISG can recommend, educate, and promote the standard. It cannot, however, bring pressure or demand organizations use it. Publishers, retailers, and wholesalers make those decisions for themselves and quite apparently the majority do not yet see the rewards. Market players need to determine the cost versus benefit and as long as distributors and retailers agree on receiving other formats, ONIX will never take a strong hold in the marketplace. After all, publishers should compete against each other with good books and not with multiple computer codes.