Effects of AM3 (Inmunoferon) on increased serum concentrations of interleukin-6 and tumour necrosis factor receptors I and II in cyclists

The aims of this study were to examine the changes in plasma concentrations of inflammatory cytokines induced by training and competition in professional cyclists. We report the serum concentrations of interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-a), tumour necrosis factor receptors I and II (TNFR-I and -II) in a prospective, randomized, double-blind trial involving the administration of AM3 (Inmunoferon), an oral booster immunomodulator, or placebo to 16 professional cyclists (n = 8 in each group) for 65 consecutive days. Serum was collected just before treatment began (baseline), at the end of pre-competition training, before the mountain stage of the competition (60 days), 4 h after finishing this stage (62 days), and 18 h after the fifth and last day of competition (65 days). To determine the normal levels of cytokines and soluble TNF receptors, individual samples from 14 moderately trained healthy controls were studied. After 60 days of training, the serum concentrations of IL-6 did not differ significantly from those at the beginning of the study for either group of cyclists (placebo and AM3). A significant rise was seen in IL-6 concentrations in both the AM3 and placebo groups at 62 days, 4 h after finishing the mountain stage. The increase was significantly greater in the placebo group than in the AM3 group. At 65 days of treatment, 18 h after the fifth and last day of competition, IL-6 concentrations were similar to those recorded at the end of the training, but were significantly higher in the placebo group than in the AM3 group. At the end of training, serum TNFR-I concentrations in both groups of cyclists were significantly lower than at baseline. The concentrations of serum TNFR-I and -II both 4 h after finishing the mountain stage and 18 h after the fifth and last day of competition were significantly higher than those recorded after training in both groups. Professional cycling competition is associated with increases in serum IL-6 and TNFR-I and -II concentrations. Inmunoferon treatment reduced significantly the concentrations of IL-6 but not those of TNFR-I and -II.     

The energetics and benefit of an arm swing in submaximal and maximal vertical jump performance

The aims of this study were to investigate the energy build-up and dissipation mechanisms associated with using an arm swing in submaximal and maximal vertical jumping and to establish the energy benefit of this arm swing. Twenty adult males were asked to perform a series of submaximal and maximal vertical jumps while using an arm swing. Force, motion and electromyographic data were recorded during each performance and used to compute a range of kinematic and kinetic variables, including ankle, knee, hip, shoulder and elbow joint powers and work done. It was found that the energy benefit of using an arm swing appears to be closely related to the maximum kinetic energy of the arms during their downswing, and increases as jump height increases. As jump height increases, energy in the arms is built up by a greater range of motion at the shoulder and greater effort of the shoulder and elbow muscles but, as jump height approaches maximum, these sources are supplemented by energy supplied by the trunk due to its earlier extension in the movement. The kinetic energy developed by the arms is used to increase their potential energy at take-off but also to store and return energy from the lower limbs and to "pull" on the rest of the body. These latter two mechanisms become more important as jump height increases with the pull being the more important of the two. We conclude that an arm swing contributes to jump performance in submaximal as well as maximal jumping but the energy generation and dissipation sources change as performance approaches maximum.     

Food attitudes in female athletes: association with menstrual cycle length

The aim of this study was to examine the relationship between indicators of risk of disordered eating, body image and varied menstrual cycle lengths. Altogether, 151 female athletes were invited from 16 sports and 70 female non-athletic controls were recruited from a university lecture class. The participants completed several surveys, including demographics, menstrual cycle history, physical activity, Eating Disorder Inventory (EDI) and the Three Factor Eating Questionnaire (TFEQ). Selected EDI subscales were summed to reflect eating disorder risk and body image. Menstrual cyclicity was based on self-reported cycle length for the last 6 months (normal cycles = 26-32 days, irregular cycles < or =26 or >32 days). Athletes overall had more irregular cycles (29.1%) than the non-athletes (15.7%) (P < 0.05). There were significant differences in scores for eating disorder risk, body dissatisfaction, drive for thinness, cognitive restraint (TFEQ) and disinhibition (TFEQ), only when athletes were divided based on menstrual cyclicity (i.e. irregularly cycling athletes had higher scores than athletes with normal menstrual cycle lengths). No differences in these scores were found between non-athletes with normal or irregular menstrual cycle lengths. In conclusion, irregularly short or long menstrual cycle length is associated with subtle indications of higher risk of disordered eating in female athletes.     

Fourth-grade students' motivational changes in an elementary physical education running program

Achievement goal theory and the expectancy-value model of achievement choice were used to examine fourth-grade students' motivational changes in an elementary physical education running program. In fall and spring of the school year, participants (N = 113; 66 boys, 47 girls) completed questionnaires assessing achievement goals, expectancy beliefs, subjective task values, and intention for future running participation. They also completed a timed 1-mile (1.6 km) run. The number of laps they ran/walked during the school year was used to assess students' persistence/effort. Results indicated the students improved their run but became less motivated about running while participating in a year-long running program. Children's beliefs about how good they were in the running program (i.e., expectancy beliefs) and their perceptions of how interesting and fun it was (i.e., interest) emerged as the strongest positive predictors of their motivation for running over time. These findings provide strong empirical evidence that expectancy beliefs and interest are essential to children's motivation in elementary physical education.     

“中國農民戰爭”教學(续)

第二课教師在問課之後,便轉到農民戰争第二階段的史實。太平天國的上層統治階級蜕化了。在残殺楊秀清之後,隨着便出现一個由高級官僚組成的新封建階級。軍事将領和負責管理地産的官吏们奪取了土地後,自己變成地主。‘人民大衆失去對自己領袖的信心,——中國的歷史家寫道——因而閃避他们’(参閥r、c、卡拉——莫爾查教授著的‘太平軍’。莫斯科,一九五○版,第一。八頁)。r、E、葉非莫夫在插寫一八五六年政變後太平天國的情形的時候,指出了‘人民的、反封建性質的運動和脫離人民的太平軍的領導政策之間的差別,越來越大了’(‘中國近代史概要’一九五一年第二版,第六一頁)。     

伟大的共产主义建设工程

一年多以前,在伟大的俄罗斯的伏尔加河的沿岸,在古比雪夫城和斯大林格勒城附近,世界上最巨大的水力发电站的建设工作,大规模的展开起来了。在伏尔加河的中游和下游地方将要用泥士和钢骨水泥的堤防把河分隔开来,由于这种堤防,就有巨大的蓄水池——古比雪夫“海”和斯大林格勒“海”形成起来,从那里伏尔加河的河水灌溉着伏尔加河左岸和里海沿岸的干燥和半沙漠地带。此外,蓄水池的河水贮藏,也保证了水力发电站的机器整年不断地工作。     

七歲兒童的特點

兒童到了七歲年齡,在生理和心理上已經具備實施有系統的學校教育所必需的基本條件。這些就是神經系統比較堅固,神經疲勞程度比較早幾年減少,由此使兒童可以省去午睡,還有就是注意能力比較過去更为耐久。七歲兒童所達到的智力發展程度,和所積累的相當多的經驗,已使他能有基本的邏輯來討論問題,能對許多不複雜的現象作分析和     

为和平而斗争是科学家的神圣任务

伟大的俄国公民与科学家克里孟脱·阿尔喀基也维奇季米里雅捷夫在革命前他所写的名著“植物与干旱的斗争”中说:“如果他(人)将自已耗费于相互斗争(隐蔽的或公开的)的力量,一致地集中于不流血的征服自然的斗争中,如果即使是他浪费于发明杀人武器的     

最佳功率负荷:一种简单有效的测试和训练手段

<正>最佳功率负荷（Optimum power load,OPL）是指在运动中产生最大输出功率时所对应的外部负荷。该概念源于力-速曲线关系,在递增负重测试中,通过专门的仪器（如线性传感器等）测量杠铃的轨迹速度,再结合负荷推导出OPL。已有多项研究证明OPL与运动表现、专项特征之间的关联性,以及其对竞技水平产生营养的影响,并讨论其在测试和训练方面潜在的应用价值。