The sensitivity of the alternative maximal accumulated oxygen deficit method to discriminate training status     

Alessandro M. Zagatto  Fabio Y. Nakamura  Fabio Milioni  Willian E. Miyagi  Rodrigo A. B. de Poli  Johnny Padulo 《Journal of sports sciences》2017,35(24):2453-2460

The purpose of the study was to investigate the sensitivity of an alternative maximal accumulated oxygen deficit (MAOD_ALT) method to discriminate the “anaerobic” capacity while comparing: least trained (LT) participants (n = 12), moderately trained (MT) participants (n = 12), endurance trained (ET) participants (n = 16), and rugby (RG) players (n = 11). Participants underwent a graded exercise test on a treadmill and a supramaximal effort for assessing MAOD_ALT. MAOD_ALT was calculated as the sum of oxygen equivalents from the phosphagen and glycolytic metabolic pathways. MAOD_ALT was significantly higher (P < 0.05) in RG (64.4 ± 12.1 mL · kg^?1) than in ET (56.8 ± 5.4 mL · kg^?1; effect size [ES] = 0.77; +13.5%), MT (53.8 ± 5.3 mL · kg^?1; ES = 1.08; +19.8%), and LT (49.9 ± 4.5 mL · kg^?1; ES = 1.50; +36.4%). In addition, the magnitude-based inference analysis revealed that MAOD_ALT was likely (LT vs. MT), very likely (MT vs. RG, and ET vs. RG) and most likely (LT vs. ET, and LT vs. RG) different between all groups, except for MT and ET, which presented an unclear difference. In conclusion, MAOD_ALT was sensitive enough to distinguish the “anaerobic” capacity in individuals with different training status, especially for RG players compared with LT participants and MT participants.  相似文献   

Uneducating South Africa: The failure to address the 1910–1993 legacy     

Fedderke  Johannes W.  de Kadt  Raphael  Luiz  John M. 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》2000,46(3-4):257-281

This paper analyses various data on the South African schooling system since 1910. The data collected for the study cover a wide range of education indicators, from pupil enrolments, pupil teacher ratios, real expenditure (aggregate and per capita), matriculation pass rates, to some indicators of the quality of matriculation passes. The authors provide an indication of both inputs into and outputs of the educational system. In broad terms, the data indicate that from an educational perspective South Africa followed a modernisation trajectory that, although it drew ever larger numbers of pupils into the schooling system, was partial, distorted and fundamentally dysfunctional. The educational process was strongly affected by racial factors. To the extent that education is an important determinant of long run growth performance of economies, this implies that South Africa's educational policies were inimical to its long run growth.  相似文献   

IQ vs phonological recoding skill in explaining differences between poor readers and normal readers in word recognition: Evidence from a naming task     

López  Mercedes Rodrigo  González  Juan E. Jiménez 《Reading and writing》2000,12(1-2):129-142

The aim of this study was to investigate whether differences inreading performance between poor readers and normal readers could bebetter explained by phonological recoding deficiences than IQ. A sampleof 132 Spanish children was classified into four groups according to IQ(<80; 81--90; 91--109; 110--140) and into two groups based on readingskills (poor readers vs normal readers). A word naming task was alsoadministered. We manipulated the word parameters (length, positionalsyllable frequency, and word frequency) and nonword parameters (lengthand positional syllable frequency) to find out whether students withreading disabilities would have more difficulties than normal readers innaming words under conditions that require extensive phonologicalcomputation. The results demonstrated that there were differencesbetween Spanish children who were normal readers and those who were poorreaders, independent of their IQs.  相似文献   

Muscle activity and pedal force profile of triathletes during cycling to exhaustion     

Diefenthaeler F  Coyle EF  Bini RR  Carpes FP  Vaz MA 《Sports biomechanics / International Society of Biomechanics in Sports》2012,11(1):10-19

The purpose of this study was to analyze pedaling cadence, pedal forces, and muscle activation of triathletes during cycling to exhaustion. Fourteen triathletes were assessed at the power output level relative to their maximal oxygen uptake (355 +/- 23 W). Cadence, pedal forces, and muscle activation were analyzed during start, middle, and end test stages. Normal and tangential forces increased from the start to the end of the test (-288 +/- 33 to -352 +/- 42 N and -79 +/- 45 to -124 +/- 68 N, respectively) accompanied by a decrease in cadence (96 +/- 5 to 86 +/- 6 rpm). Muscle activation increased from the start to the middle and the end in the gluteus maximus (27 +/- 5.5% and 76 +/- 9.3%) and in the vastus lateralis (13 +/- 3.5% and 27 +/- 4.4%), similar increase was observed from the start to the end in the rectus femoris and the vastus medialis (50 +/- 9.3% and 20 +/- 5.7%, respectively). Greater normal force along with enhanced activation of knee and hip extensor muscles is linked with fatigue and declines in cadence of triathletes during cycling to exhaustion.  相似文献   

Quantitative analysis of Brazilian football players' organisation on the pitch     

Moura FA  Martins LE  Anido Rde O  de Barros RM  Cunha SA 《Sports biomechanics / International Society of Biomechanics in Sports》2012,11(1):85-96

The purpose of this study was to characterise Brazilian teams' coverage area and spread on the pitch while attacking and defending and to analyse the teams' organisation in tackle and shot on goal situations. We obtained the trajectories of 223 players in eight games with a tracking method. Team area was defined as the area of the convex hull formed by players' positions. Team spread was defined as the Frobenius norm of the distance-between-player matrix. We calculated teams' area and spread over time and in situations of shots on goal (n = 233) and tackles (n = 1897). While the players attacked, spread and area (median +/- confidence interval) ranged from 322.9 +/- 0.8 to 387.8 +/- 1.0 m and from 905.4 +/- 4.4 to 1407.6 +/- 5.5 m2, respectively. On defence, the values were smaller (p < 0.05) and ranged from 283.4 +/- 0.9 to 325.8 +/- 0.9 m and from 773.8 +/- 4.6 to 1158.4 +/- 5.5 m2 for the spread and the area. In defending circumstances, the teams presented a greater area and spread when they suffered shots on goal than when the teams performed tackles. In attacking situations, the teams presented a greater area and spread when they suffered tackles than when they performed shots on goal. The results allowed showing the attacking-defending interaction between Brazilian teams.  相似文献   

Analysis of the interplay between knowledge and performance management in industrial clusters     

Rafael Henrique Palma Lima  Luiz Cesar Ribeiro Carpinetti 《知识管理研究与实践》2012,10(4):368-379

The concept of industrial clustering has been studied in-depth by policy makers and researchers from many fields, mainly due to the competitive advantages it may bring to regional economies. Companies often take part in collaborative initiatives with local partners while also taking advantage of knowledge spillovers to benefit from locating in a cluster. Thus, Knowledge Management (KM) and Performance Management (PM) have become relevant topics for policy makers and cluster associations when undertaking collaborative initiatives. Taking this into account, this paper aims to explore the interplay between both topics using a case study conducted in a collaborative network formed within a cluster. The results show that KM should be acknowledged as a formal area of cluster management so that PM practices can support knowledge-oriented initiatives and therefore make better use of the new knowledge created. Furthermore, tacit and explicit knowledge resulting from PM practices needs to be stored and disseminated throughout the cluster as a way of improving managerial practices and regional strategic direction.  相似文献   

Effect of strength training on rate of force development in older women     

Gurjão AL  Gobbi LT  Carneiro NH  Gonçalves R  Ferreira de Moura R  Cyrino ES  Altimari LR  Gobbi S 《Research quarterly for exercise and sport》2012,83(2):268-275

We analyzed the effect of an 8-week strength training (ST) program on the rate of force development (RFD) and electromyographic activity (EMG) in older women. Seventeen women (M age = 63.4 years, SD = 4.9) without previous ST experience were randomly assigned to either a control (n=7) or training (n=10) group. A leg-press isometric test was used for assessment. ST (three sessions/ week, three sets of 10-12 repetition maximum, five different exercises) induced significant increases (p < .05) on peak RPD (48.4%) and on RFD) and EMG of vastus medialis at time intervals of 0-50, 0-100, 0-150, and 0-200 ms (41.1-69.2% and 43.8-64.3%, respectively). Therefore, ST resulted in favorable changes in neuromuscular responses in older women.  相似文献   

Incorporation of Caprylic Acid into a Single Cell Oil Rich in Docosahexaenoic Acid for the Production of Specialty Lipids     

Daniela Kanno Mathias  Jacqueline Piazentin Costa  Carolina Rodrigues Calvo  Roberta Claro da Silva  Attilio Converti  Nadia Segura  Ivn Jachmanin  Luiz Antonio Gioielli  Juliana Neves Rodrigues Ract 《Food Technology and Biotechnology》2020,58(4):411

  相似文献   

Debate on global warming as a socio-scientific issue: science teaching towards political literacy     

Wildson Luiz Pereira dos Santos 《Cultural Studies of Science Education》2014,9(3):663-674

The focus of this response to the original article by Tom G. H. Bryce and Stephen P. Day (Cult Stud Sci Educ. doi:10.1007/s11422-012-9407-1, 2013) is the use of empirical data to illustrate and expand the understanding of key points of their argument. Initially, I seek to discuss possible answers to the three questions posed by the authors related to: (1) the concerns to be addressed and the scientific knowledge to be taken into account in the climate change debate, (2) the attention to be paid to perspectives taken by “alarmists” and “deniers,” and (3) the approaches to be used to conduct controversial global warming debate. In this discussion, I seek to contribute to the debate proposed by the original paper, illustrating various points commented on by the authors and expanding to other possibilities, which highlight the importance of political issues in the debate. Therefore, I argue that socio-political issues must be taken into account when I aim for a scientific literacy that can enhance students’ political education. Likewise, I extend the debate presented in the original article, emphasizing the attention that should be paid to these aspects and approaching science education from a critical perspective. Highlighting only the confirmation bias without considering political implications of the debate can induce a reductionist and empiricist view of science, detached from the political power that acts on scientific activity. In conclusion, I support the idea that for a critical science education, the discussion of political issues should be involved in any controversial debate, a view, which goes beyond the confirmation bias proposed by Bryce and Day for the global warming debate. These issues are indeed vital and science teachers should take them into account when preparing their lessons for the debate on climate change.  相似文献   

高水平乒乓球运动员正手回击不同状态来球时动作的调整     

Welber Marinovic　Andrea Michele Freudenheim　Cristina Akiko Iizuka　Luiz Henrique Porto Vilani 《体育科研》2005,26(3):90-94

本研究旨在调查当高水平乒乓球运动员被要求对付不同状态来球时,如何调整他们的动作.研究对象与方法前巴西国家队高水平乒乓球男女运动员7名,均为右手持拍.运动员(平均年龄27.85±5.36岁、训练年限平均为19.14±5.24年,运动员身体状况良好,每周训练3次.运动员分别在4种状况下,对发球机发出的乒乓球进行正手击球(1)两次反弹(一次过网前一次过网后)的上旋球;(2)两次反弹的侧旋球;(3)一次反弹(过网后)的上旋球;(4)一次反弹的侧旋球.研究结果(1)乒乓球运动员采用包括动作的绝对和相对的修正以促进正手对击球的适应;(2)动作修正的本质受不同状况的约束;(3)细微动作(触球和随拍)比宏观动作(准备姿态和向前挥拍)更容易受外界状况的影响.分析与讨论(1)回击一次和两次反弹的侧旋球,运动员几乎不用调整,但侧旋球会造成成功率不高.在引拍、迎球挥拍阶段动作模式没有改变,但球拍触球、随势挥拍阶段稍有不同,此动作有利于还原部分;(2)击球动作前的选位和对手的动作趋势也会影响动作模式,但变化却是使整个动作结构的改变.  相似文献