Development and testing of a prenatal breastfeeding education intervention for Hispanic women

Many immigrant Hispanic women in the United States choose to bottle-feed rather than breastfeed. This article describes an intervention that was developed and tested in a two-step process. Two studies were undertaken. First, a qualitative inquiry explored the breastfeeding beliefs, attitudes, meanings, and practices of Hispanic women. Results informed the design of a culturally appropriate prenatal breastfeeding education intervention. Secondly, the researchers undertook a quantitative study of the intervention's success in increasing breastfeeding duration among Hispanic women. Methodology and findings of this study have implications for future interventions that promote breastfeeding.     

屁股超过脑袋瓜

霍勒斯是美国19世纪的政治家、出版家。他创办的《美国论坛报》,在美国有很大的影响,是美国发行量最大的报纸之一。     

Comparison of force-related performance indicators between heavyweight and lightweight rowers

The aim of this study was to examine biomechanical variables relating to the force production of men's Lightweight (LW) and Heavyweight (HW) rowing pairs. Seven HW and seven LW coxless pairs were studied under a range of stroke rates, from 20 spm to race rating (average of 33.7 spm for the HWs and 33.9 spm for the LWs). Each crew was equipped with biomechanical apparatus allowing the measurement of gate force, horizontal oar angle, and boat velocity. The HW crews exhibited significantly higher (p < 0.05) values for all variables examined, at all rates. Peak handle force was 26.2% to 30.2% higher in the HW group. Average handle force ranged from 18.7% to 22.1% higher than the LW group. Work per stroke was found to be 26% to 28% higher for the HW crews, and Power Per Kilogram was also greater for the HW crews, from 24.0% to 29.2%. The LWs were observed to be consistently, but not significantly, slower than the HWs (from 96.9% at the race situation, to 98.7% at 28 spm). These observations are important when considering biomechanical performance indicators in rowing, as significant changes in performance indicators may lead to only minimal alteration in boat velocity.     

Children's motivation in elementary physical education: an expectancy-value model of achievement choice

This study examined children's motivation in elementary physical education within an expectancy-value model developed by Eccles and her colleagues. Four hundred fourteen students in second and fourth grades completed questionnaires assessing their expectancy-related beliefs, subjective task values, and intention for future participation in physical education. Results indicated that expectancy-related beliefs and subjective task values were clearly distinguishable from one another across physical education and throwing. The two constructs were related to each other positively. Children's intention for future participation in physical education was positively associated with their subjective task values and/or expectancy-related beliefs. Younger children had higher motivation for learning in physical education than older children. Gender differences emerged and the findings provided empirical evidence supporting the validity of the expectancy-value model in elementary physical education.     

The angiogenetic effect of intramuscular administration of b-FGF and a-FGF on cardiac muscle: the influence of exercise on muscle angiogenesis

Although angiogenetic therapy using recombinant growth factors holds much hope for the treatment of ischaemic diseases, there are still many unanswered questions, including the method of administration, the correct dose of these factors, and the duration of the therapeutic approach. Exercise has also been suggested to induce neovascularizaiton in muscles. We evaluated the angiogenetic effects of the intramuscular administration of basic-fibroblast growth factor (b-FGF) and acidic-fibroblast growth factor (a-FGF) in rat heart, compared with rats who exercised daily. In conclusion, both the intramuscular administration of b-FGF and exercise increased significantly angiogenesis in the heart in contrast to the intramuscular administration of a-FGF, which was ineffective.     

Success in elite cycling: A prospective and retrospective analysis of race results

The development of peak performances is a main research focus in sports science. It is unclear how many former top junior athletes achieve success in the elite class later. The aim of the present study was to examine the careers of athletes who participated in major junior or adult/elite cycling events using prospective and retrospective analysis of competition results. The official results of major junior (age < or = 18 years) and elite (age > 18 years) cycling races from 1980 to 2004 were analysed. Age-related aspects, career lengths, and success were compared between riders who presented results in both junior and elite races (JUNIOR ELITE) and riders who had no junior race results (ELITE ONLY). Altogether, 27,454 results of 8004 athletes from 108 countries were collected. We found that 29.4% of the elite athletes had participated in junior World Championships, and that 34% of the participants in junior World Championships later participated in major elite competitions. JUNIOR ELITE athletes are significantly more successful in several cycling disciplines and have their first and last elite result at a younger age than ELITE ONLY athletes. No difference was found in career lengths. The data presented here emphasize the importance of long-term training programmes in the development of peak performance in cycling.     

Do achievement goals mediate stereotype threat?: an investigation on females' soccer performance

This research investigated stereotype threat effects on women's performance in sports and examined the mediation of this effect by achievement goals. The influence of two stereotypes-relative to the poor athletic ability and the poor technical soccer ability of women-were studied. Fifty-one female soccer players were randomly assigned to one of three conditions, introducing the task as diagnostic of athletic ability, technical soccer ability, or sports psychology. Next, they filled out a questionnaire measuring achievement goals and performed a soccer dribbling task. Results showed that compared with the control condition, females' performance significantly decreased in the athletic ability condition and tended to decrease in the technical soccer ability condition. Moreover, participants endorsed a performance-avoidance (relative to performance-approach) goal when the stereotypes were activated. However, this goal endorsement was not related to performance. The implications of these results for understanding the role of stereotypes in gender inequalities in sports are discussed.     

力量素质和决定力量素质的诸因素

沃罗比耶夫是苏联原国家举重队总教练,医学副博士,本人亦曾经多次创造90公斤级举重世界纪录。他在1977年所著《举重运动的生理学与训练》一书,系统地总结了苏联优秀举重运动员的训练经验,并使之与运动生物力学、运动生理学、运动医学紧密结合,融为一体。该书资料丰富,数椐处理严格、论据明确,科学性强。对我国举重教练员、运动员、运动医生有较大参考价值。由于时隔五年,个别论述已失之陈旧。本刊拟摘其精华,编译登载。本期刊登的是该书第二章“力量素质和决定力量素质的各种因素”的主要内容,以后将陆续编译刊登其它部分。     

Ball launch conditions for skilled golfers using drivers of different lengths in an indoor testing facility

The displacement of the golf ball struck by a driving club is affected by several player characteristics and equipment parameters and their interrelationships. Some modelling and simulation studies have shown a relationship between shaft length and clubhead speed, supported by a few experimental studies. The aim of the present study was to examine the relationship between driver length and ball launch conditions in an indoor test facility using a ball launch monitor. Nine males considered to be skilled golfers participated in the study. Four driving clubs of total length 117, 119, 124, and 132 cm were assembled from commercially available components and were used to strike golf shots while initial ball velocity, backspin rate, and launch angles were measured. Statistical analysis identified a significant difference in initial launch speed due to club length, a significant difference between participants, but no difference between the trials for a given golfer. A positive trend was noted between backspin and launch angle for all four clubs, and significant inverse associations between initial launch speed and backspin rate and launch angle. However, the combined launch conditions associated with increasing length were not considered optimal, with uncontrolled swingweight and moment of inertia effects considered to be limiting factors.