排序方式： 共有72条查询结果，搜索用时 218 毫秒
61.
Da Silva JF Guglielmo LG Carminatti LJ De Oliveira FR Dittrich N Paton CD 《Journal of sports sciences》2011,29(15):1621-1628
The aim of this study was to assess the validity (Study 1) and reliability (Study 2) of a novel intermittent running test (Carminatti's test) for physiological assessment of soccer players. In Study 1, 28 players performed Carminatti's test, a repeated sprint ability test, and an intermittent treadmill test. In Study 2, 24 players performed Carminatti's test twice within 72 h to determine test-retest reliability. Carminatti's test required the participants to complete repeated bouts of 5 × 12 s shuttle running at progressively faster speeds until volitional exhaustion. The 12 s bouts were separated by 6 s recovery periods, making each stage 90 s in duration. The initial running distance was set at 15 m and was increased by 1 m at each stage (90 s). The repeated sprint ability test required the participants to perform 7 × 34.2 m maximal effort sprints separated by 25 s recovery. During the intermittent treadmill test, the initial velocity of 9.0 km · h(-1) was increased by 1.2 km · h(-1) every 3 min until volitional exhaustion. No significant difference (P > 0.05) was observed between Carminatti's test peak running velocity and speed at VO(2max) (v-VO(2max)). Peak running velocity in Carminatti's test was strongly correlated with v-VO(2max) (r = 0.74, P < 0.01), and highly associated with velocity at the onset of blood lactate accumulation (r = 0.63, P < 0.01). Mean sprint time was strongly associated with peak running velocity in Carminatti's test (r = -0.71, P < 0.01). The intraclass correlation was 0.94 with a coefficient of variation of 1.4%. In conclusion, Carminatti's test appears to be avalid and reliable measure of physical fitness and of the ability to perform intermittent high-intensity exercise in soccer players. 相似文献
62.
Luiz Cláudio Andrade Souza 《Journal of The Franklin Institute》2011,348(4):777-789
This paper studies parameter estimation for a class of linear, continuous, time-varying dynamic systems whose state-space model's matrices are affine combinations of static matrix coefficients and the aforementioned time-varying scalar parameters. It is assumed that the coefficient matrices are all known, that the state is mensurable, and that the parameters are bounded piecewise continuous functions of time. Estimation methods are developed from basic equations for a single parameter first, and later extended to multiple parameters. 相似文献
63.
The quasi-totality of social scientists who studied screening for cervical tumours identified such screening with a single method: the Pap smear (exfoliative cytology). This article explains that this method was not valid everywhere. The history of screening for cervical cancer in Brazil displays an alternative method for detecting cervical malignancies: a direct observation of the cervix with a specific instrument--the colposcope. The development of this method in Brazil in the 1940s and 1950s reflected a complex mixture of professional interests, government policies, and regional, local and charitable initiatives. While the use of colposcopy for cervical tumour screening was phased out in the 1970s and 1980s, the long lifespan and widespread diffusion of this method illuminates the irreducible contingency of specific developments in science, technology and medicine. Seen from the vantage point of Brazil, the Western model for preventing cervical malignancies no longer appears self-evident Alternative choices might have led to the development of different material and visual cultures of medicine, stimulated different patterns of medical specialization and division of medical labour, produced different links between malignancies, women, gynaecologists, epidemiologists and public health experts, and shaped different health policies. 相似文献
64.
This work discusses the use of Darwin’s ‘Tree of Life’ as a didactic analogy and metaphor in teaching evolution. It investigates
whether biology teachers of pupils from 17 to 18 years old know Darwin’s text ‘Tree of Life’. In addition, it examines whether
those teachers systematically employ either the analogies present in that text or other analogies between the tree and evolution,
and whether they adopt a specific methodology for teaching with analogies and metaphors (A&M). The academic training of teachers
regarding use of A&M is review briefly. A diagnostic study was carried out with biology teachers in a public school in the
town of Contagem in the state of Minas Gerais in Brazil. The data were obtained through direct observation, questionnaires
and a focus group. The teachers pointed out in the questionnaires that some details of Darwin’s analogy are utilized as a
resource. However, analysis of the data indicates that the ‘Tree of Life’ text is not known or utilized in class. At the same
time, the teachers state that they use aspects of the tree as a didactic resource to teach evolution and that its use facilitates
the learning of content. The teachers have little knowledge of specific methodologies of teaching with analogies and metaphors,
revealing that their training is incomplete in this area. 相似文献
65.
Luiz Henrique Porto Vilani Dietmar Martin Samulski 《体育科研》2005,26(3):31-36,54
本研究包含以下几方面内容1.情境领导Ⅱ型模式在巴西乒乓球队训练管理工作中及教练员对运动员的领导关系中的应用情况调查.2.根据运动员的表现,运动员的满意程度,以及教练与运动员之间的相互关系来分析教练员的后续领导行为是否受前阶段管理工作的影响.3.分析运动员的调查结果与相应教练员调查结果的一致性,及其领导管理行为是否为运动队管理多元模式中的一种.研究对象与方法调查对象为61名巴西12～18岁乒乓球运动员和10名乒乓球教练,这些队员和教练均为国家级水平,研究中以运动员满意度问卷形式和运动领导管理标准进行评估.研究结果教练员先前的领导行为影响运动员对教练员的看法,以及运动员的满意程度、教练与运动员相互之间的关系等.那些运动成绩较好的、经验相对丰富的、教练监督指导得比较多的运动员,他们的问卷答案与教练员的问卷结果有很高的一致性.对教练员的训练教导工作和民主行为方面,男子运动员的答案要比女子运动员表现出较高的一致性.女运动员对教练员的个别对待方式与民主行为表现出较好的满意度.运动员的问卷结果与相应教练员的调查结果的一致性在很大程度上依赖于训练过程中产生的良好效果与运动员的满意度,这反映了多元领导模式的规则.另外,虽然我们的研究并没有很好地验证情境领导Ⅱ模式在运动队训练管理中的应用情况,但是,调查分析结果表明了合适的多元领导模式在运动队训练工作中进行有效领导的重要性.这些结果也说明在多元领导模式的基础上,采用足够合理的方法是检验情境领导Ⅱ模式在运动训练管理中应用情况的关键. 相似文献
66.
67.
Juliano Fernandes-da-Silva Carlo Castagna Anderson Santiago Teixeira Lorival José Carminatti Luiz Guilherme Antonacci Guglielmo 《Journal of sports sciences》2016,34(24):2238-2245
ABSTRACTThe aim of this study was to examine the relationship between the peak velocity derived from the Carminatti Test (T-CAR) (PVT-CAR) and physical match performance in young soccer players. Thirty-three youth soccer players were recruited from 2 non-professional clubs. Friendly matches and small-sided game were performed. Physical match demands were assessed using Global Positioning System (GPS) technology. On a separate occasion, the players were submitted to the T-CAR. Players were categorised into 3 groups based on their T-CAR performance: Low (PVT-CAR ≤ P33), Intermediate (P33 > PVT-CAR < P66) and High (PVT-CAR ≥ P66). The PVT-CAR (15.5 ± 0.7 km·h?1) was significantly related to high-intensity activities (HIA; r = 0.78, P < 0.001), high-intensity running (HIR; r = 0.66, P < 0.001), sprinting (r = 0.62, P < 0.001) and total distance (TD) covered (r = 0.47, P < 0.01) during friendly matches. The PVT-CAR was strongly correlated with the amount of HIA (r = 0.81, P < 0.001), HIR (r = 0.85, P < 0.001) and TD covered (r = 0.81, P < 0.001) during small-sided game. No significant correlation was observed between the PVT-CAR and distance of sprinting (r = 0.49, P = 0.067) during small-side game. Furthermore, players in the High group covered significantly more TD (10%) and did more HIA (42%), sprinting (31%) and HIR (25%) during friendly matches compared to the players classified as having Low performance on the T-CAR. These differences still remained after adjusting for chronological age (CA), maturity and body size. In conclusion, the current study gives empirical support to the ecological and construct validity of this novel field test (T-CAR) as an indicator of match-related physical performance in young soccer players during pubertal years. 相似文献
68.
Heloisa Chalmers Sisla Cinquetti Luiz Marcelo de Carvalho 《Environmental Education Research》2007,13(5):565-577
This paper investigates aspects of content knowledge related to teaching and learning about solid waste, focusing on the processes of learning and teaching by Elementary School teachers in Brazil, in two modalities of continuing education: courses and school‐based meetings. We analyse elements of teachers' reflections whilst referring to three dimensions of environmental education: knowledge, values (ethic and aesthetic), and political participation. We identify which dimensions are predominant, or absent, and the aspects included and developed in projects elaborated by teachers. The results raise issues we consider important to support teacher education and curriculum programmes and help teachers develop more substantial, critical and effective projects about the subject. 相似文献
69.
Juliano F. Da Silva Luiz G.A. Guglielmo Lorival J. Carminatti Fernando R. De Oliveira Naiandra Dittrich Carl D. Paton 《Journal of sports sciences》2013,31(15):1621-1628
Abstract The aim of this study was to assess the validity (Study 1) and reliability (Study 2) of a novel intermittent running test (Carminatti's test) for physiological assessment of soccer players. In Study 1, 28 players performed Carminatti's test, a repeated sprint ability test, and an intermittent treadmill test. In Study 2, 24 players performed Carminatti's test twice within 72 h to determine test–retest reliability. Carminatti's test required the participants to complete repeated bouts of 5 × 12 s shuttle running at progressively faster speeds until volitional exhaustion. The 12 s bouts were separated by 6 s recovery periods, making each stage 90 s in duration. The initial running distance was set at 15 m and was increased by 1 m at each stage (90 s). The repeated sprint ability test required the participants to perform 7 × 34.2 m maximal effort sprints separated by 25 s recovery. During the intermittent treadmill test, the initial velocity of 9.0 km · h?1 was increased by 1.2 km · h?1 every 3 min until volitional exhaustion. No significant difference (P > 0.05) was observed between Carminatti's test peak running velocity and speed at VO2max (v-VO2max). Peak running velocity in Carminatti's test was strongly correlated with v-VO2max (r = 0.74, P < 0.01), and highly associated with velocity at the onset of blood lactate accumulation (r = 0.63, P < 0.01). Mean sprint time was strongly associated with peak running velocity in Carminatti's test (r = ?0.71, P < 0.01). The intraclass correlation was 0.94 with a coefficient of variation of 1.4%. In conclusion, Carminatti's test appears to be avalid and reliable measure of physical fitness and of the ability to perform intermittent high-intensity exercise in soccer players. 相似文献
70.
Luiz H. P. Vieira Sérgio A. Cunha Renato Moraes Fabio A. Barbieri Rodrigo Aquino Lucas de P. Oliveira 《Research quarterly for exercise and sport》2018,89(2):210-220
Purpose: The purpose of this study was to compare the kicking performance of young soccer players in the U9 to U20 age groups. Method: Three hundred and sixty-six Brazilian players were evaluated on an official pitch using three-dimensional kinematics to measure (300 Hz) ball velocity (Vball), foot velocity (Vfoot), Vball/Vfoot ratio, last stride length, and distance between the support foot and the ball. Simultaneously, a two-dimensional procedure was also conducted to compute (60 Hz) the mean radial error, bivariate variable error, and accuracy. Possible age-related differences were assessed through one-way analysis of variance and magnitude-based inferences. Results: Ball velocity increased by 103% (p < .001, η2 = .39) from the U11 age group (48.54 ± 8.31 km/hr) to the U20 age group (98.74 ± 16.35 km/hr). Foot velocity presented a 59% increase (p < .001, η2 = .32) from the U11 age group (49.08 ± 5.16 km/hr) to U20 (78.24 ± 9.49 km/hr). This finding was due to improvement in the quality of foot–ball impact (Vball/Vfoot ratio) from U11 (0.99 ± 0.13 a.u.) to U20 (1.26 ± 0.11 a.u.; p < .001, η2 = .25). Parameters such as mean radial error and accuracy appeared to be impaired during the growth spurt (U13–U15). Last stride length was correlated, low to moderately high, with Vball in all age groups (r = .36–.79). Conclusions: In summary, we concluded that simple biomechanical parameters of kicking performance presented distinct development. These results suggest that different training strategies specific for each age group could be applied. We provide predictive equations to aid coaches in the long-term monitoring process to develop the kick in soccer or search for talented young players. 相似文献