Pre-game hydration status, sweat loss, and fluid intake in elite Brazilian young male soccer players during competition     

Da Silva RP  Mündel T  Natali AJ  Bara Filho MG  Alfenas RC  Lima JR  Belfort FG  Lopes PR  Marins JC 《Journal of sports sciences》2012,30(1):37-42

In this study, we assessed the pre-game hydration status and fluid balance of elite young soccer players competing in a match played in the heat (temperature 31.0 ± 2.0 ° C, relative humidity 48.0 ± 5.0%) for an official Brazilian soccer competition. Fluid intake was measured during the match, as were urine specific gravity and body mass before and after the game to estimate hydration status. Data were obtained from 15 male players (age 17.0 ± 0.6 years, height 1.78 ± 0.06 m, mass 65.3 ± 3.8 kg); however, data are only analysed for 10 players who completed the full game. The mean (± s) sweat loss of players amounted to 2.24 ± 0.63 L, and mean fluid intake was 1.12 ± 0.39 L. Pre-game urine specific gravity was 1.021 ± 0.004, ranging from 1.010 to 1.025. There was no significant correlation between sweat loss and fluid intake (r = 0.504, P = 0.137) or between urine specific gravity and fluid intake (r = -0.276, P = 0.440). We conclude that young, native tropical soccer players started the match hypohydrated and replaced about 50% of the sweat lost. Thus, effective strategies to improve fluid replacement are needed for players competing in the heat.  相似文献   

Energetic demand and physical conditioning of table tennis players. A study review     

Alessandro Moura Zagatto  Miran Kondric  Beat Knechtle  Pantelis Theo Nikolaidis  Billy Sperlich 《Journal of sports sciences》2018,36(7):724-731

Table tennis is a racket sport characterised by an intermittent movement profile, including short rallies interspersed with short breaks. In contrast to other racket sports, information is lacking regarding the: (i) physiological responses during table tennis matches and training; and (ii) practical recommendations for enhancing aerobic and anaerobic performance in table tennis by improving cardio-metabolic and neuro-muscular fitness, anthropometry and nutritional strategies. Therefore, this review article attempts to narratively provide an overview of the physiology of table tennis by describing the metabolic mechanisms underlying match play and outlining a framework for practical recommendations for improving cardio-metabolic and neuro-muscular fitness, anthropometry as well as nutritional strategies. A second aim was to stimulate future research on table tennis and to point out study limitations in this context. In general, the most important finding is that the rally duration is short at around 3.5s, with a longer rest time of around 8–20s, resulting in an effort-rest ratio ranging from 0.15 to 0.22 in official matches and energetic demands during match relatively low. Future studies should focus on the relationship between energetic demand and table tennis performance with a view to predicting performance in table tennis using physiological parameters.  相似文献   

Have the poor found their own appropriate     

Lúcia Radler dos Guaranys  Cláudio de Moura Castro 《International Journal of Educational Development》1982,2(2):163-174

Correspondence schools in Brazil are entirely in the hands of private entrepreneurs and ignored, even despised, by official educators. Yet, as this paper shows, they can, —in many cases, do—, provide helpful education for those who have no other access to educational opportunity. Indeed, they appear to offer the most equal form of opportunity. Accompanying their benefits, however, are many imperfections and abuses. The paper identifies five areas where government intervention could help both the public and the correspondence schools, without stifling their current vitality.  相似文献   

Overeducation in developing economies: How can we test for it, and what does it mean?     

Aashish Mehta  Jesus Felipe  Pilipinas Quising  Sheila Camingue 《Economics of Education Review》2011,30(6):1334-1347

A worker is said to be overeducated if he/she has acquired more education than is required to perform his/her job. In the absence of data measuring the number of years of schooling required to perform particular jobs, we propose a new approach to testing for overeducation. Overeducation is confirmed if we observe that education levels rose in jobs that offer very low returns to education and that underwent little technological change. Using labor force surveys from four developing countries, we find evidence of overeducation in unskilled jobs in the Philippines, mild evidence in Mexico, and little evidence in India and Thailand. We show that a job's mean and modal years of schooling are poor proxies for required education. We also show that overeducation sometimes increases within unskilled jobs, even while a growing share of educated workers enter skilled jobs. This may be because the quality of education segments the labor market.  相似文献   

LABRADOR: Efficiently publishing relational databases on the web by using keyword-based query interfaces     

Filipe Mesquita  Altigran S. da Silva  Edleno S. de Moura  Pável Calado  Alberto H.F. Laender 《Information processing & management》2007

A vast amount of valuable information, produced and consumed by people and institutions, is currently stored in relational databases. For many purposes, there is an ever increasing demand for having these databases published on the Web, so that users can query the data available in them. An important requirement for this to happen is that query interfaces must be as simple and intuitive as possible. In this paper we present LABRADOR, a system for efficiently publishing relational databases on the Web by using a simple text box query interface. The system operates by taking an unstructured keyword-based query posed by a user and automatically deriving an equivalent SQL query that fits the user’s information needs, as expressed by the original query. The SQL query is then sent to a DBMS and its results are processed by LABRADOR to create a relevance-based ranking of the answers. Experiments we present show that LABRADOR can automatically find the most suitable SQL query in more than 75% of the cases, and that the overhead introduced by the system in the overall query processing time is almost insignificant. Furthermore, the system operates in a non-intrusive way, since it requires no modifications to the target database schema.  相似文献   

Special Theory of Relativity,Conceptual Change and History of Science     

Villani  Alberto  Arruda  Sergio M. 《Science & Education》1998,7(1):85-100

The problem of the learning of Special Theory of Relativity by secondary and college students is analysed. It is stressed that the results of the studies which attempted to evaluate students' learning are ambiguous and intriguing. Also the history of the emergence and acceptance of the theory by the scientific community itself at the beginning of the 20th century is analysed. Three fundamental steps are described: a) the publication of Lorentz's Transformation Equations, their interpretation in the context of the Electron Theory and their consequent acceptance by the scientific community; b) the presentation by Einstein of two postulates, namely the Relativity Principle and Einstein's Principle of the Invariance of the Speed of Light, and their partial acceptance; c) the rejection of the Electron Theory and the final acceptance of the Theory of Relativity simultaneously with the development of the General Theory of Relativity. The analogy between historical and learning processes provides some suggestions to improve the teaching of the theory.  相似文献   

The Universality of Science and Traditional Chinese Medicine     

de Felipe  Íñigo Ongay 《Science & Education》2021,30(6):1353-1370

Science & Education - This paper represents a philosophical appraisal of Traditional Chinese Medicine (TCM) from the point of view of the philosophy of science. As it is generally the case with...  相似文献   

Physicochemical Characterization,Stability and Cytotoxicity of a Blue Dye Obtained from Genipap Fruit (Genipa americana L.)     

Camila Verly de Miranda Sabino  Brbara Janaína Paula da Silva  Danielle Lima Bezerra de Menezes  Felipe Moura Araújo da Silva  Tatiane Pereira de-Souza  Hector Henrique Ferreira Koolen  dley Antonini Neves de Lima  Emerson Silva Lima 《Food Technology and Biotechnology》2021,59(1):103

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Reading habits of pre-service teachers / Trayectorias de lectura del profesorado en formación     

Felipe Munita 《Cultura y Educación》2013,25(3):448-475

Abstract

Recent studies on the reading habits of those studying to be teachers have questioned the reading identity of the people who are to become the future mediators of reading in school environments. Within this framework, the current research constitutes an exploratory hermeneutic interpretative study on the reading habits of pre-service teachers, in order to establish a reader profile for this population group, which is the focus of our study. The information is taken from students at Universidad Autónoma de Barcelona. It has been collected through sharing life experiences and has undergone a mixed content statistical analysis. The results reveal a standard profile defined by discontinuous reading habits, precarious intertexts and current practices mainly related to bestsellers.  相似文献   

Language Arts Performance Assignments: Generalizability Studies of Local and Central Ratings     

Jose Felipe Martinez  Pete Goldschmidt  David Niemi  Eva L. Baker  Roxanne M. Sylvester 《Educational Assessment》2013,18(3-4):267-282

We conducted generalizability studies to examine the extent to which ratings of language arts performance assignments, administered in a large, diverse, urban district to students in second through ninth grades, result in reliable and precise estimates of true student performance. The results highlight three important points when considering the use of performance assessments in large-scale settings: (a) Rater training may significantly impact reliability; (b) simple rater agreement indices do not provide enough information to assess the reliability of inferences about true student achievement; and (c) assessments adequate for relative judgments of student performance do not necessarily provide sufficient precision for absolute criterion-referenced decisions.  相似文献