Label-free microfluidic characterization of temperature-dependent biomolecular interactions     

Nguyen T  Pei R  Landry DW  Stojanovic MN  Lin Q 《Biomicrofluidics》2011,5(3):34118-341187

We present a microfluidic approach to characterizing temperature-dependent biomolecular interactions. Solvated L-arginine vasopressin (AVP) and its immobilized RNA aptamer (spiegelmer) were allowed to achieve equilibrium binding in a microchip at a series of selected temperatures. Unbound AVP were collected and analyzed with matrix-assisted laser desorption∕ionization mass spectrometry (MALDI-MS), yielding melting curves that reveal highly temperature-dependent zones in which affinity binding (36–45 °C) or dissociation (25–33 °C and 50–65 °C) occurs. Additionally, temperature-dependent binding isotherms were constructed; from these, thermodynamic quantities involved in binding were extracted. The results illustrated a strong change in heat capacity of interaction for this system, suggesting a considerable thermodynamic influence controlling vasopressin-spiegelmer interaction.  相似文献   

A comparison of anthropometric and training characteristics of Ironman triathletes and Triple Iron ultra-triathletes     

Knechtle B  Knechtle P  Rüst CA  Rosemann T 《Journal of sports sciences》2011,29(13):1373-1380

We examined differences in anthropometry and training between 64 Triple Iron ultra-triathletes competing over 11.4 km swimming, 540 km cycling, and 126.6 km running, and 71 Ironman triathletes competing over 3.8 km swimming, 180 km cycling, and 42.2 km running. The association of anthropometry and training with race time was investigated using multiple linear regression analysis. The Triple Iron ultra-triathletes were smaller (P < 0.05), had shorter limbs (P < 0.05), a higher body mass index (P < 0.05), and larger limb circumferences (P < 0.01) than the Ironman triathletes. The Triple Iron ultra-triathletes trained for more hours (P < 0.01) and covered more kilometres (P < 0.01), but speed in running during training was slower compared with the Ironman triathletes (P < 0.01). For Triple Iron ultra-triathletes, percent body fat (P = 0.022), training volume per week (P < 0.0001), and weekly kilometres in both cycling (P < 0.0001) and running (P < 0.0001) were related to race time. For Ironman triathletes, percent body fat (P < 0.0001), circumference of upper arm (P = 0.006), and speed in cycling training (P = 0.012) were associated with total race time. We conclude that both Triple Iron ultra-triathletes and Ironman triathletes appeared to profit from low body fat. Triple Iron ultra-triathletes relied more on training volume in cycling and running, whereas speed in cycling training was related to race time in Ironman triathletes.  相似文献   

Use of dual-task methodology for skill assessment and development: examples from rugby league   总被引：2，自引：1，他引：1  

Gabbett T  Wake M  Abernethy B 《Journal of sports sciences》2011,29(1):7-18

We assessed the attentional demands of drawing and passing in rugby league players and investigated the effects of single-task and dual-task training on the acquisition, retention, and transfer of skill in these athletes. In Study 1, high-skilled and lesser-skilled rugby league players performed a standardized 2-on-1 drill under single-task (primary skill in isolation) and dual-task (primary skill while performing a secondary verbal tone recognition task) conditions. No differences were detected in primary task performance between groups, although the performance of the high-skilled players was more resistant to skill decrement under dual-task conditions. In Study 2, high-performance rugby league players were randomly allocated to either a single-task or dual-task training group. Each group underwent 8 weeks of training between the pre- and post-test sessions. While the mean improvement for draw and pass proficiency under dual-task conditions in the dual-task training group was greater than in the single-task training group (10.0% vs. 2.3%), the differences, while providing a moderate effect size (d = 0.57), were not statistically significant. These results suggest that the attentional demands of drawing and passing are reduced in high-skilled rugby league players compared with their lesser-skilled counterparts. In addition, compared with single-task training, dual-task training appears to improve the ability to perform dual-task draw and pass tasks (possibly through an improvement in time-sharing skills). Further studies are required to verify the efficacy of dual-task training as a training stimulus.  相似文献   

Effects of strategy use on children's motor performance in a continuous timing task     

Liu T  Jensen JL 《Research quarterly for exercise and sport》2011,82(2):198-209

The purposes of this study were to associate age-related performance deficits in children with the use of recall strategies and to determine whether children who performed poorly in cycling would benefit from learning a recall strategy. In Experiment 1, 18 younger children (ages 5-7years) and 18 older children (ages 8-10 years) were asked to recall selected pedaling cadences. The majority of the older children used strategies and performed with less error than the younger children. In Experiment 2, children with a high number of errors in Experiment 1 were assigned to an experimental or a control group. The children in the experimental group were taught to use a specific recall strategy. The results showed that children who received the instruction in strategy use improved their performance.  相似文献   

The effect of climbing wall use on the grip strength of fourth-grade students     

Lirgg CD  Dibrezzo R  Gray M  Esslinger T 《Research quarterly for exercise and sport》2011,82(2):350-354

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Effect of hand paddles and parachute on the index of coordination of competitive crawl-strokers   总被引：1，自引：1，他引：0  

Telles T  Barbosa AC  Campos MH  Junior OA 《Journal of sports sciences》2011,29(4):431-438

We investigated the effects of hand paddles and parachute on the relative duration of stroke phases and index of coordination of competitive crawl-strokers. Eleven male-swimmers (age: 21.9 ± 4.5 years; 50-m best time: 24.23 ± 0.75 s) were evaluated in four maximal-intensity conditions: without equipment, with hand paddles, with parachute, and with both hand paddles and parachute. Relative stroke phase duration of each arm, swimming velocity, and stroke rate were analysed from video (60 Hz). The index of coordination was quantified based on the lag time between propulsive phases of each arm, which defined the coordination mode as catch-up, opposition or superposition. The stroke rate decreased in all conditions (P < 0.05) and swimming velocity decreased with parachute and with paddles + parachutes (P < 0.05). The coordination mode changed from catch-up in free swimming (-2.3 ± 5.0%) to opposition with paddles (-0.2 ± 3.8%), parachute (0.1 ± 3.1%), and paddles + parachute (0.0 ± 3.2%). Despite these variations, no significant differences were observed in relative duration of right and left arm-stroke phases, or in index of coordination. We conclude that the external resistances analysed do not significantly influence stroke phase organization, but, as a chronic effect, may lead to greater propulsive continuity.  相似文献   

The role of athlete narcissism in moderating the relationship between coaches' transformational leader behaviors and athlete motivation     

Arthur CA  Woodman T  Ong CW  Hardy L  Ntoumanis N 《运动与训练心理学杂志》2011,33(1):3-19

Leadership research that examines follower characteristics as a potential moderator of leadership effectiveness is lacking. Within Bass's (1985) transformational leadership framework, we examined follower narcissism as a moderator of the coach behavior-coach effectiveness relationship. Youth athletes (male = 103, female = 106) from the Singapore Sports Academy (mean age = 14.28, SD = 1.40 years) completed the Differentiated Transformational Leadership Inventory (Callow, Smith, Hardy, Arthur, & Hardy, 2009), the Narcissistic Personality Inventory (Raskin & Terry, 1988), and indices of follower effort. Multilevel analyses revealed that athlete narcissism moderated the relationship between fostering acceptance of group goals and athlete effort and between high performance expectations and athlete effort. All the other transformational leader behaviors demonstrated main effects on follower effort, except for inspirational motivation.  相似文献   

Daredevils and early birds: Belgian pioneers in automobile racing and aerial sports during the belle époque     

Ameye T  Gils B  Delheye P 《国际体育史杂志》2011,28(2):205-239

During the belle époque, Belgium was a trend-setting nation in many domains, including motorised sports. Belgian automobile racers and pilots shattered world records and became international stars. Striking was the shift in sports. Indeed, around 1896, sporting members of the leisure class stepped from the bicycle into the automobile and, around 1908, from the automobile into the airplane. Although these motorised sports were extremely expensive, this article shows that sportsmen and sportswomen from the working class could achieve upward social mobility through their performances. The achievements of these motorised pioneers had a major impact and wide-ranging significance. They laid the foundations for the expansion of the automobile industry and the emergence of civilian and military aviation.  相似文献   

以艺术为名，“艺”境对话公众     

房三才  文思奇R.R.T 《科技文萃》2014,(12):30-45

在工业设计领域里,一件好的产品除了其本身的设计、制作之外,如何让产品落地,走入寻常百姓的生活中往往是最难以把握的一点。从那些耀然跨世的杰作身上,你总能找到许多真正抓住人们日常生活细节的亮点。  相似文献   

最值钱的宝贝     

T·V·帕德玛  庞启帆 《中华活页文选(初中版)》2014,(11):23-25

霍尔沃与他的母亲住在比约斯托大森林附近的一间小屋里。为了维持母子俩的生活,霍尔沃的母亲从早到晚都在缝制衣服。她的手掌因此结满了老茧,她的视力也因长期在昏暗的灯光下工作而降低了。她只有一件破旧的羊毛披肩,在冬天缝制衣服时,经常冷得发抖,不停咳嗽。霍尔沃憎恨自己年龄太小而帮不上母亲的忙。冬夜,看到母亲的身体在微微颤抖,霍尔沃说：＂妈妈,我长大后,一定要赚很多很多的钱。到那时,我会给你买很多很多衣服,  相似文献