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91.
Goaltenders in ice hockey are the only players that are on the ice for the entire game. Their position exposes them to impacts from collisions with other players, falls to the ice, and puck impacts. In competitive ice hockey leagues, head injuries resulting from puck impacts have been reported with some cases resulting in ending the player’s career. Considerable research has been conducted to assess the performance of hockey helmets; however, few have assessed the performance of goaltenders’ masks. The purpose of this study was to compare the capacity of four goaltenders’ masks for the protection from puck impact as measured by head acceleration and peak force. A Hybrid III headform was fitted with four different goaltender masks and impacted with a hockey puck in three locations at 25 m/s. The masks were found to vary in the level of protection they offered as the mask with the thickest liner resulted in lower forces than the thinnest mask for side impacts; however, the thinnest mask resulted in the lowest force for front impacts. Despite performance differences at specific locations, no one mask proved to be superior as peak acceleration and peak force values did not exceed the thresholds necessary for concussion.  相似文献   
92.
The recent professionalization of rugby union makes it an excellent achievement context in which to examine the relationship between achievement goal orientations and the perceived purposes of sport as a function of competitive standard. During the 1996–97 season, 73 professional and 106 amateur rugby players in England completed a series of questionnaires assessing their achievement goal orientations, beliefs about the purposes of rugby and demographic information. The results of a canonical correlation analysis revealed a conceptually coherent relationship between achievement goal orientations and purposes of rugby. Specifically, a high ego/ moderate task orientation was positively related to fitness, aggression and financial remuneration as significant purposes of rugby. Professional players scored higher on those purposes of rugby related to aggression, financial remuneration and fitness, but lower on sportspersonship than amateur players. Professional players also reported higher task and ego goal orientations than amateur players. The findings are discussed in terms of the differences in lifestyle and motivation of professional and amateur rugby union players.  相似文献   
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Abstract

This study investigated the effects of iron supplementation (18 mg per day) on the serum iron, total iron binding capacity (TIBC), hemoglobin levels, and percent hemoglobin saturation with iron of female college basketball athletes. The serum iron and hemoglobin levels of ten varsity basketball athletes and seven control subjects (nonathletes) were measured (pretest) prior to the basketball season and again at the end of the season. Iron supplements, no supplements, or a placebo tablet were given during the 4-month experimental period. ANOVA statistical analyses revealed that the iron supplementation was of no value in raising serum iron, TIBC, percent saturation, and hemoglobin levels and that a 4-month basketball training regimen and season did not significantly lower serum iron and hemoglobin levels.  相似文献   
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Abstract

Reaction time of the batter in Softball is important because of short pitching distance and the speed of the pitcher. Nine pitchers were tested for speed and had an average velocity of 59.95 mph and a mean reaction time of .215 sec. was found for 258 students tested. With these averages, the ball would be 29.33 ft. from home plate before 116 of these students began their swing and in 41 cases the ball would be less than 20 ft from the plate. Pitchers with greater velocity would decrease the success of the batter if the reaction time remains the same.  相似文献   
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Abstract

Self-control over factors involving task-related information (e.g., feedback) can enhance motor learning. It is unknown if these benefits extend to manipulations that do not directly affect such information. The purpose of this study was to determine if self-control over the amount of practice would also facilitate learning. Participants learned to throw a dart using their nonpreferred hand. The self-control (SC) group decided when to stop practice. The yoked group completed the same number of trials as their SC counterparts. Results revealed the SC group was more accurate during transfer and in recalling the number of trials completed. These findings indicate that self-control benefits extend to factors that do not directly alter task-related information.  相似文献   
99.
This study investigated the simultaneous impact of demographic, personality, intelligence, and (prior) study performance factors on students' academic achievement in a three-year academic problem-based psychology program. Information regarding students' gender, age, nationality, pre-university education, high school grades, Big Five personality traits, intelligence (i.e., numerical, verbal, spatial), observed learning activities, and self-study time was collected among almost 1800 students enrolled in this psychology bachelor program at Erasmus University Rotterdam between 2003 and 2009. Academic achievement was measured by students' yearly number of acquired credit points, a course test, and a knowledge progress test. Multiple regression analyses showed that observed learning activities, first- and second-year performance, high school grades, conscientiousness, and verbal ability were most strongly and consistently related to academic achievement in the bachelor. Other student factors also contributed to academic achievement, but their influence was less prominent and mainly restricted to the first year. These results suggest that (prior) educational achievements and observable learning activities are most important for academic success in a problem-based learning bachelor program.  相似文献   
100.
This ethnographic case study investigated the science practices of teachers at one public elementary magnet school in light of how school culture influenced science curriculum design and instruction. The purpose of the study was to address how school culture impacted the school??s overall treatment of science as a viable content area. Key informant teachers were interviewed to explore their personal beliefs and values, teaching, access to materials, and views of the adopted integrated thematic curriculum model and magnet structure. The resulting data, triangulated with informal observation and artifact collection, were analyzed using a theoretical framework that emphasized five interdependent school culture indicators (values, beliefs, practices, materials, and problems). Findings suggest that the school??s culture adversely influenced the treatment of science.  相似文献   
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