Carnosine in health and disease     

Guilherme Giannini Artioli  Craig Sale  Rebecca Louise Jones 《European Journal of Sport Science》2019,19(1):30-39

Abstract

Carnosine was originally discovered in skeletal muscle, where it exists in larger amounts than in other tissues. The majority of research into the physiological roles of carnosine have been conducted on skeletal muscle. Given this and the potential for muscle carnosine content to be increased with supplementation, there is now a large body of research examining the ergogenic effects (or otherwise) of carnosine. More recent research, however, points towards a potential for carnosine to exert a wider range of physiological effects in other tissues, including the brain, heart, pancreas, kidney and cancer cells. Taken together, this is suggestive of a potential for carnosine to have therapeutic benefits in health and disease, although this is by no means without complication. Herein, we will provide a review of the current literature relating to the potential therapeutic effects of carnosine in health and disease.  相似文献   

Resting Bradycardia,Enhanced Postexercise Heart Rate Recovery and Cardiorespiratory Fitness in Recreational Ballroom Dancers     

Carlos Janssen Gomes da Cruz  Guilherme Eckhardt Molina  Luiz Guilherme Grossi Porto  Luiz Fernando Junqueira Jr 《Research quarterly for exercise and sport》2017,88(3):371-376

Purpose: In a cross-sectional study design, we evaluated the resting heart rate (HR_baseline) and exercise and postexercise stress test-related chronotropic responses in male practitioners of recreational ballroom dancing (BD; n = 25, M_age = 26.6 ± 6.1 years) compared to a control group of insufficiently active nondancers (CG; n = 25, M_age = 25.9 ± 4.5 years). Method: All participants underwent a submaximal exercise test. At 85% of the maximal predicted HR, the recovery protocol was started, and heart rate recovery (HRR) was recorded during 1-min intervals for 5 min. Results: Compared with CG, BD showed lower HR_baseline (70 beats per minute [bpm] vs. 62 bpm, respectively, U = 143, p < .05, ES = .46), lower preexercise HR (94 bpm vs. 86 bpm, U = 157, p < .05, ES = .42), longer exercise test duration (346 s vs. 420 s, U = 95.5, p < .05, ES = .59), and higher HRR for 5 min postexercise (U = 1.29–1.89, p < .05, ES = .33–.50) as follows: 1st min (32 bpm vs. 40 bpm), 2nd min (45 bpm vs. 53 bpm), 3rd min (51 bpm vs. 58 bpm), 4th min (55 bpm vs. 59 bpm), and 5th min (59 bpm vs. 63 bpm). The coefficient of HRR from the 1st min to the 5th min postexercise was similar in both groups (U = 229–311, p > .05, ES = < .10–.22). Conclusion: Heightened cardiovascular functional status characterized by favorable enhanced chronotropic dynamics appears to occur in practitioners of recreational ballroom dancing, which suggests that this modality of exercise may result in health benefits.  相似文献   

Do cognitive training strategies improve motor and positive psychological skills development in soccer players? Insights from a systematic review     

Maamer Slimani  Nicola Luigi Bragazzi  David Tod  Alexandre Dellal  Olivier Hue  Foued Cheour 《Journal of sports sciences》2016,34(24):2338-2349

ABSTRACT

Soccer players are required to have well-developed physical, technical and cognitive abilities. The present systematic review, adhering to Preferred Reporting Items for Systematic reviews and Meta-Analysis guidelines, examined the effects of cognitive training strategies on motor and positive psychological skills development in soccer performance and identified the potential moderators of the “cognitive training–soccer performance” relationship. Thirteen databases were systematically searched using keywords related to psychological or cognitive training in soccer players. The review is based on 18 studies, employing 584 soccer players aged 7–39 years. Cognitive strategies, particularly imagery, appear to improve sports performance in soccer players. Regarding imagery, the combination of two different types of cognitive imagery training (i.e., cognitive general and cognitive specific) has a positive influence on soccer performance during training, whereas motivational imagery (i.e., motivational general-arousal, motivational general-mastery and motivational specific) enhance competition performance. Younger soccer players employ cognitive general and cognitive specific imagery techniques to a greater extent than older soccer players. Combined cognitive training strategies were more beneficial than a single cognitive strategy relative to motor skills enhancement in elite (particularly midfielders) and amateur (i.e., when practising complex and specific soccer skills in precompetitive period) soccer players. In conclusion, it appears that there are differences in cognitive/psychological training interventions, and their efficacy, according to whether they are directed towards training or competition, and the age, standard and playing position of the players.  相似文献   

Paving the Olympic Dream: The Politics of the 2007 Pan-American Games in Rio de Janeiro     

Guilherme Nothen 《国际体育史杂志》2016,33(1-2):203-216

Abstract

The making of the 2007 Pan-American Games, held in the city of Rio de Janeiro, marked the beginning of the long transformation that this city would undergo in connection to sports mega-events. This paper revisits how the 2007 Pan-American Games were largely produced under the promise that its legacies, particularly the infrastructural ones, could be effectively mobilized in order to strengthen the chances of bringing the Olympics to Brazil for the first time. Whereas this rhetoric has proven somewhat successful in helping the city to secure the right to host the 2016 Olympics, the alleged connection between both events has shown to be much more limited than its proponents had initially advertized. In reality, most of the venues constructed for the Pan-American Games had to be thoroughly renovated for the Olympics, while some of them presented structural problems and/or failed to meet the standards imposed by international sports federations.  相似文献   

Centralization and Freedom in EducationNotes and Comments∗     

Alexandre Vexliard 《比较教育学》1970,6(1):37-47

  相似文献   

Metaphors we’re colonised by? The case of data-driven educational technologies in Brazil     

Giselle Martins dos Santos Ferreira  Luiz Alexandre da Silva Rosado  Márcio Silveira Lemgruber  Jaciara de Sá Carvalho 《Learning, Media and Technology》2020,45(1):46-60

ABSTRACT

This article discusses issues concerning the spread of data-driven educational technologies in Brazil. Here, as elsewhere, educational technology continues to be promoted optimistically as the bearer of a panacea for historically-rooted social problems. Whilst some of these technologies have indeed contributed to important widening-participation programmes in the last two decades, widespread advocacy of technological ‘solutionism’, reflected in gradually stronger policy demands for efficiencies to be improved through ‘innovation’, has supported a relentless marketisation of the country’s educational systems. As transnational corporations position themselves to take control of key areas of these systems, threatening to restructure the whole sector, data-driven educational technologies provide the latest example in a series of ‘new’ ideas offered in an ever-expanding market. Based on the notion of ‘conceptual metaphors’, which encapsulate specific ways of perceiving, thinking and relating with the world, this article examines key metaphors underpinning discourses surrounding data-driven educational technologies in Brazil. In particular, the article analyses ways in which these specific metaphors may be promoting perspectives that ignore difference and obscure broader questions concerning education, thus contributing to the reproduction of previously existing problems and supporting new forms of colonisation.  相似文献   

Gender,Science and Technology in Brazil     

Plonski GA  Saidel RG 《Minerva》2001,39(2):217-238

This essay considers gender in relation toBrazilian science and technology. It reviewsleading studies in the field, and offers briefbiographies of pioneering women in science.While there is still much room for improvement,the essay suggests that the situation of womenin science experienced significant progressduring the closing decades of the twentiethcentury.  相似文献   

Bookreviews     

A. D. C. Peterson  Brian Holmes  G. De Landsheere  Helena W. F. Stellwag  Oskar Anweiler  J. O. J. Vanden Bossche  Abraham Robinson  F. I. Calvert  H. H. Stern  J. F. Willatt  Sydney Taylor  M. J. Langeveld  M. A. Brimer  T. N. Postlethwaite  Alexandre Vexliard 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1964,10(1):106-126

  相似文献   

Symbolising the real of mathematics education     

Alexandre Pais 《Educational Studies in Mathematics》2015,89(3):375-391

  相似文献   

Revisiting Cross-document Structure Theory for multi-document discourse parsing     

Erick Galani Maziero  Maria Lucía del Rosário Castro Jorge  Thiago Alexandre Salgueiro Pardo 《Information processing & management》2014

Multi-document discourse parsing aims to automatically identify the relations among textual spans from different texts on the same topic. Recently, with the growing amount of information and the emergence of new technologies that deal with many sources of information, more precise and efficient parsing techniques are required. The most relevant theory to multi-document relationship, Cross-document Structure Theory (CST), has been used for parsing purposes before, though the results had not been satisfactory. CST has received many critics because of its subjectivity, which may lead to low annotation agreement and, consequently, to poor parsing performance. In this work, we propose a refinement of the original CST, which consists in (i) formalizing the relationship definitions, (ii) pruning and combining some relations based on their meaning, and (iii) organizing the relations in a hierarchical structure. The hypothesis for this refinement is that it will lead to better agreement in the annotation and consequently to better parsing results. For this aim, it was built an annotated corpus according to this refinement and it was observed an improvement in the annotation agreement. Based on this corpus, a parser was developed using machine learning techniques and hand-crafted rules. Specifically, hierarchical techniques were used to capture the hierarchical organization of the relations according to the proposed refinement of CST. These two approaches were used to identify the relations among texts spans and to generate multi-document annotation structure. Results outperformed other CST parsers, showing the adequacy of the proposed refinement in the theory.  相似文献