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1.
Fabio De Siati Guillaume Laffaye Giorgio Gatta Antonio Dello Iacono Johnny Padulo 《Journal of sports sciences》2016,34(15):1466-1472
Testing is one of the important tasks in any multi-step sport programme. In most ball games, coaches assess motor, physical and technical skills on a regular basis in early stages of talent identification in order to further athletes’ development. The purpose of the study was to investigate anthropometric variables and vertical jump heights as a free throw effectiveness predictor in water-polo players of different age groups. Two hundred and thirty-six young (10–18 years) male water-polo players partitioned into three age groups underwent anthropometric variables’ measures and squat- and countermovement-jump tests, and performed water-polo free throws. Anthropometric variables, vertical jump heights and throw speed – as a proxy for free throw effectiveness – resulted different over age groups. Particularly, throw speed changed from 9.28 to 13.70 m · s?1 (+48%) from younger to older players. A multiple-regression model indicated that body height, squat-jump height and throw time together explain 52% of variance of throw speed. In conclusion, tall height, high lower limb power and throwing quickness appeared to be relevant determinants for effective free throws. Such indications can help coaches during talent identification and development processes, even by means of novel training strategies. Further research is needed over different maturity statuses. 相似文献
2.
The nexus between college choice and persistence 总被引：2，自引：3，他引：2
Edward P. St. John Michael B. Paulsen Johnny B. Starkey 《Research in higher education》1996,37(2):175-220
Initial student commitments have long been considered an influence on persistence, but the reasons why students choose to attend a college have seldom been considered as dimensions of initial commitments that could influence persistence processes and outcomes. This study used NPSAS-87 to examine the influence of finance-related reasons for choosing a college on persistence decisions. The findings include (1) finance-related choices have direct and indirect influences on whether students persist in college; and (2) market-based, monetary measures of financial aid, tuition costs, housing costs, and other living costs have a substantial direct effect on persistence. 相似文献
3.
Achraf Ammar Hamdi Chtourou Khaled Trabelsi Johnny Padulo Mouna Turki Kais El Abed 《Journal of sports sciences》2015,33(4):358-368
The aim of this study was to investigate the performance of an Olympic-Weightlifting session training at three times of the day on the performance related to biochemical responses. Nine weightlifters (21 ± 0.5 years) performed, in randomised order, on three Olympic-Weightlifting training (snatch, clean and jerk) sessions (08:00 a.m., 02:00 p. m., 06:00 p. m.). Blood samples were collected: before, 3 min and 48 h after each training session. Haematological parameters and markers of muscle injury were assessed. Resting oral temperature and rating of perceived exertion (RPE) were also assessed during each session. ANOVA showed that the performance was better (P < 0.001) at 02:00 p. m. with a less RPE (P < 0.01) compared to the morning and the evening sessions while there was higher (P < 0.05) oral temperature at 06:00 p. m. versus 08:00 a.m. and 02:00 p. m. Muscle damage changed immediately (without significant effect after 48 h) after the training sessions with lower values ??in the evening compared to the morning. In conclusion, the afternoon training is more effective than morning or evening sessions for weightlifters. Therefore, coaches and weightlifters should be advised to schedule their training session in the afternoon hour. 相似文献
4.
Johnny Hartz S?raker 《Ethics and Information Technology》2012,14(3):209-219
It has become commonplace to hold the view that virtual surrogates for the things that are good in life are inferior to their actual, authentic counterparts, including virtual education, virtual skill-demanding activities and virtual acts of creativity. Virtual friendship has also been argued to be inferior to traditional, embodied forms of friendship. Coupled with the view that virtual friendships threaten to replace actual ones, the conclusion is often made that we ought to concentrate our efforts on actual friendships rather than settle for virtual replacements. The purpose of this paper is to offer a balanced and empirically grounded analysis of the relative prudential value of actual and virtual friendship. That is, do actual and virtual friendships differ when it comes to enhancing our subjective well-being? In doing so, I will discuss a number of presuppositions that lie behind common criticisms of virtual friendship. This will include, among other considerations, their potential for replacing actual friendship, as well as the possibility for self-disclosure, trust, sharing and dynamic spread of happiness in virtual worlds. The purpose is not to arrive at a firm, normative conclusion, but rather to introduce a number of considerations that we should take into account in our individual deliberations over which role virtual friendships ought to have in our unique life situations. 相似文献
5.
6.
Johnny Saldaña 《Multicultural Perspectives》2013,15(3):14-18
Two workshops on Augusto Boal's Forum Theatre were conducted with two high school student groups coincidentally divided by class: one lower to lower‐middle, and one upper‐middle to upper. Students created oppression scenarios for improvisation that focused primarily on horizontal hostility: the group versus the stigmatized individual. The two workshop environments, however, differed in quality due to the facilitator's perception of class as an influential variable. Students in the upper middle‐class to upper‐class group made choices and exhibited actions characteristic of those living in the culture of affluence and privilege. I reflect critically on the event's implications for multicultural educators. 相似文献
7.
In the golf instructional literature, the putting stroke is typically given higher priority than green reading and aiming. The main purpose of this study was to assess the importance of the putting stroke for direction consistency in golf putting. Kinematic stroke parameters were recorded from 71 elite golf players (mean handicap = 1.8, s = 4.2) on 1301 putts from about 4 m. Of the different factors deciding stroke direction consistency, face angle was found to be the most important (80%), followed by putter path (17%) and impact point (3%). This suggests that improvements in consistency of putter path and impact point will have very little effect on overall putting direction consistency and should not be prioritized in the training of elite players. In addition, mean stroke direction variability for an elite player (European Tour) was found to be 0.39 degrees, which is good enough to hole about 95% of all 4-m putts. In practice, however, top professionals in tournaments only hole about 17% of 4-m putts. We conclude that the putting stroke of elite golfers has a relatively minor influence on direction consistency. 相似文献
8.
The polynomial solutions of the equation fy″ + gy′ + λy = 0 are obtained and classified for f, g, and λ certain second-degree, first-degree, and zero-degree polynomials, respectively. Applications are given illustrating the use of these polynomials in the construction of amplitude functions and system functions and in tree counting. In particular, all-pole and rational filter functions are considered which include as special cases the Chebyshev, Butterworth, elliptic, Bessel, and various transitional filter functions. 相似文献
9.
The aim of this study was to investigate the reliability of a new infrared light based method (IR40) for recording temporal stride patterns during treadmill running. The IR40 device, emitting a tight web of 40 infrared light beams 10 mm above the treadmill running surface, was compared to a previously
validated electro-pneumatic contact shoe (CS) method while nine well-trained athletes ran at 2.8, 3.3, 3.9, 4.4, 5.0, and
5.6 m s−1. Disconnection and reconnection of the IR beams marked the stance phase. The sampling rate was 500 Hz for both methods. The
stance phase duration was on average 11.5 (±8.4) ms longer with the IR40 than with the CS depending on earlier touch down (8.3 ± 6.2 ms) and delayed toe off (3.2 ± 5.3 ms) registrations. Significantly
different stance phases were recorded between all velocities and for both methods. Thus, despite the fact that the IR40 systematically measured a somewhat longer stance phase duration than CS, the IR40 is nonetheless useful for temporal stride analysis during treadmill running. 相似文献
10.
Much of the training of competitive telemark skiers is performed as dry-land exercises. The specificity of these exercises is important for optimizing the training effect. Our aim here was to study the activation of the knee extensor musculature and knee angular displacement during competitive telemark skiing and during dry-land strength training exercises to determine the specificity of the latter. Specificity was analysed with respect to angular amplitude, angular velocity, muscle action and electromyographic (EMG) activity. Five male telemark skiers of national and international standard volunteered to participate in the study, which consisted of two parts: (1) skiing a telemark ski course and (2) specific dry-land strength training exercises for telemark skiing (telemark jumps and barbell squats). The angular displacement of the right knee joint was recorded with an electrogoniometer. A tape pressure sensor was used to measure pressure between the sole of the foot and the bottom of the right ski boot. Electromyographic activity in the right vastus lateralis was recorded with surface electrodes. The EMG activity recorded during maximum countermovement jumps was used to normalize the EMG activity during telemark skiing, telemark jumps and barbell squats. The results showed that knee angular displacement during telemark skiing and dry-land telemark jumps had four distinct phases: a flexion (F1) and extension (E1) phase during the thrust phase of the outside ski/leg in the turn/jump and a flexion (F2) and extension (E2) phase when the leg was on the inside of the turn/jump. The vastus lateralis muscle was activated during F1 and E1 in the thrust phase during telemark skiing and telemark jumps. The overall net knee angular amplitude was significantly greater (P < 0.05) for telemark jumps than for telemark skiing. Barbell squats showed a knee angular amplitude significantly greater than that in telemark skiing (P < 0.05). The mean knee angular velocity of the F1 and E1 phases during telemark skiing was about 0.47 rad x s(-1); during barbell squats, it was about 1.22 rad x s(-1). The angular velocity during telemark jumps was 2.34 and 1.59 rad x s(-1) in the F1 and E1 phase, respectively. The normalized activation level of the EMG bursts during telemark skiing, telemark jumps and barbell squats was 70-80%. In conclusion, the muscle action and level of activation in the vastus lateralis during the F1 and E1 phases were similar during telemark skiing and dry-land exercises. However, the dry-land exercises showed a larger knee extension and flexion amplitude and angular velocity compared with telemark skiing. It appears that an adjustment of knee angular velocity during barbell squats and an adjustment of knee angle amplitude during both telemark jumps and barbell squats will improve specificity during training. 相似文献