Relative shank to thigh length is associated with different mechanisms of power production during elite male ergometer rowing

The effect of anthropometric differences in shank to thigh length ratio upon timing and magnitude of joint power production during the drive phase of the rowing stroke was investigated in 14 elite male rowers. Rowers were tested on the RowPerfect ergometer which was instrumented at the handle and foot stretcher to measure force generation, and a nine segment inverse dynamics model used to calculate the rower's joint and overall power production. Rowers were divided into two groups according to relative shank thigh ratio. Time to half lumbar power generation was significantly earlier in shorter shank rowers (p = 0.028) compared to longer shank rowers, who showed no lumbar power generation during the same period of the drive phase. Rowers with a relatively shorter shank demonstrated earlier lumbar power generation during the drive phase resulting from restricted rotation of the pelvic segment requiring increased lumbar extension in these rowers. Earlier lumbar power generation and extension did not appear to directly affect performance measures of the short shank group, and so can be attributed to a technical adaptation developed to maximise rowing performance.     

Tackle and ruck technique proficiency within academy and senior club rugby union

ABSTRACT

This study examined the validity of a tool that assesses tackle and ruck technique in training and established reference data for tackle, ball-carry and ruck technique at different levels of play in rugby union. One hundred and thirty-one amateur rugby union players; 37 senior, 51 first-grade academy and 43 second-grade academy players, participated in a two-on-two contact drill. The drill was filmed and the players’ tackle, ball-carry and ruck technique were assessed using standardized technical criteria. Senior level players scored significantly higher in all three assessments; tackle technique senior vs academy 1^st (p < 0.01, effect size (ES) = 0.7, moderate), senior vs academy 2^nd (p < 0.01, ES = 0.7, moderate); ball-carry technique senior vs academy 1^st (p < 0.01, ES = 0.6, moderate), senior vs academy 2^nd (p < 0.01, ES = 0.8, moderate); ruck technique senior vs academy 1^st (p < 0.01, ES = 0.7, moderate), senior vs academy 2^nd (p < 0.01, ES = 0.4, small). These findings emphasize the importance of developing contact technique to allow players to progress to higher levels, and provide validity to an assessment tool which can facilitate this process.     

Understanding Greek Primary School Children's Comprehension of Sun Exposure

The purpose of this study was to assess Greek primary (1st to 6th grade) school children's understanding of sun exposure during summer vacation. Our results show that children know the damaging effects of long time exposure and the precautions that should be taken during sun bathing (sun glasses, hat, umbrella, sunscreen, etc). Nevertheless, they do not seem to avoid being exposed between 12.00 A.M. and 15.00 P.M., which is the most dangerous time. The socioeconomic status of father has no effect on the attitude of children towards taking protection measures when exposed to the sun, however, the educational status of the mother appears to influence children's reported knowledge and behaviour. Place of residence (urban or rural areas) and gender does not influence their knowledge on the sun's damaging effects and the precautions they should take. Finally, as children grow older they seem to gradually reduce the protective measures they take.     

Effects of model-centered instruction on effectiveness, efficiency, and engagement with ill-structured problem solving

The goals of this study were to investigate the timing and the mechanism by which two types of model-centered instruction (MCI)—expert modeling (EM) and self-guided modeling (SGM)—might be made increasingly effective, efficient, and engaging for learners with different levels of expertise. The 62 pre-service and in-service evaluators who participated in the study were randomly assigned to one of these two types of MCI. The participants in the EM group were provided with the conceptual models used by experts to solve ethical conflicts within program evaluation. The participants in SGM group received no guidance in developing their own mental models. Regarding instructional effectiveness measures, there were no significant differences between the two types of MCI. However, inexperienced learners in the EM group invested less instructional effort and time than did those in the SGM group. In addition, inexperienced learners in the EM group also exhibited more engagement than did those in the SGM group. Therefore, EM is likely to be the more appropriate instructional design for inexperienced learners. Expert modeling required experienced learners to invest more mental effort, because if the conceptual model of the expert was redundant, it required them to integrate the previous schema with resulting overload of their working memory. Regardless of the types of MCI employed, the inexperienced participants showed significantly higher levels of attention and satisfaction than did the experienced participants.     

New Zealand Maori Stories and Symbols: Family Value Lessons for Western Counsellors

Maori stories and symbols offer Westerns counselors a rich heritageof wisdom. This article provides a summary of key Maori mythologyand worldview highlighting the profound significance of sacredgeography—manifested in the marae (meeting ground) andthe wharenui (meeting house)—and family (whenau) imbedded in genealogy (whakapa). The authors then considerrelated significance for contemporary Maori, offer questions andapplications for western counsellors, and acknowledge essentialconsultation from a Maori staff advisor (te kaiurungi).     

Unintended consequences on gender diversity of high-tech growth and labor market polarization

There has been considerable media coverage highlighting the lack of gender diversity in Silicon Valley, stressing the relatively low participation of women in the high-tech economy. Austin offers a unique case for testing whether similar gender issues characterized other high-tech regions because the city has historically benefited from the expansion of Silicon Valley’s large high-tech firms since the 1980s. The gender-biased business practices identified in Silicon Valley firms may have been transferred to their branch plants in Austin. Our analysis shows women’s losses in middle-skill occupation employment shares were concentrated in the low-tech industry and were partially offset by job share gains in high-skill occupations in the same sector between 1980 and 2015. Men’s losses in middle-skill occupation job share were also mainly concentrated in the low-tech sector but were partially offset by employment share gains in high-skill occupations only in the high-tech industry during this period. Women made large gains in relative real median wages only in high-skill occupations in the high-tech industry while their relative real median wages in other skill occupations and in the low-tech industry stagnated around zero during this period. Men’s gains in relative median wages were also concentrated only in the high-tech industry but were less than half of women’s and were negative (between ?10 and ?21 percent) in other occupations in the high-tech industry and across all occupations in the low-tech industry. As noted in previous studies, the impact of job polarization is not well understood across sectors and gender. This study finds the high-tech industry in Austin has had unintended consequences in terms of job polarization across gender, providing relatively fewer job opportunities in high-skill occupations to women than men but offering much higher gains in relative real median wages to women than men. Males also found relatively more job opportunities in high-skill occupations in the high-tech industry than women but experienced only half of women’s gains in relative median wages in this industry between 1980 and 2015.     

Customer participation and new product performance: Towards the understanding of the mechanisms and key contingencies

In a study of 243 firms of varying sizes across 14 different industries, we investigate the effect of customer participation on new product development performance. We confirm that overall customer participation is positively related to new product development performance and that the effect is mediated by innovativeness. We also demonstrate that these effects are contingent upon absorptive capacity of the firm in question such that firms with high absorptive capacity stand to gain more from engaging their customers in new product development than firms with low absorptive capacity, especially at the later stages of the NPD process. The results are robust to alternative estimation techniques, measures employed to operationalize key concepts, and the industrial makeup of the sample. Post hoc analyses provide non-trivial managerial implications for the decision makers at the firm level.