Fluid balance of elite Brazilian youth soccer players during consecutive days of training

Abstract

In this study we investigated pre-training hydration status, fluid intake, and sweat loss in 20 elite male Brazilian adolescent soccer players (mean ± s: age 17.2 ± 0.5 years; height 1.76 ± 0.05 m; body mass 69.9 ± 6.0 kg) on three consecutive days of typical training during the qualifying phase of the national soccer league. Urine specific gravity (USG) and body mass changes were evaluated before and after training sessions to estimate hydration status. Players began the days of training mildly hypohydrated (USG > 1.020) and fluid intake did not match fluid losses. It was warmer on Day 1 (33.1 ± 2.4°C and43.4 ± 3.2% relative humidity; P < 0.05) and total estimated sweat losses (2822 ± 530 mL) and fluid intake (1607 ± 460 mL) were significantly higher (P < 0.001) compared with Days 2 and 3. Data also indicate a significant correlation between the extent of sweat loss and the volume of fluid consumed (Day 1: r = 0.560, P = 0.010; Day 2: r = 0.445, P = 0.049; Day 3: r = 0.743, P = 0.0001). We conclude that young, native tropical soccer players arrive hypohydrated to training and that they exhibit voluntary dehydration; therefore, enhancing athletes' self-knowledge of sweat loss during training might help them to consume sufficient fluid to match the sweat losses.     

Heart Rate Response to a Modified Harvard Step Test: Males and Females,Age 10–69

Abstract

The residents of an entire community are being examined periodically in an effort to determine the etiologic factors which lead to impaired health. As a part of this study, a submaximal test consisting of stepping onto an 8-inch bench at the rate of 24 steps/ minute for three minutes was administered to 2696 males and 2568 females, aged 10–69. The ECG, from which heart rate (HR) was measured, was recorded before, during, and after the exercise. Resting, exercise, and postexercise HR's are significantly higher for females at all ages. Pre-exercise HR decreases from age 10 to about age 25 in males and females, and shows little age change thereafter. In both males and females the terminal (3 minute) HR decreases from age 10 to 35, remains fairly constant to age 55, and decreases thereafter. The postexercise HR decreases again at age 65 in males and females. Reclining pre-exercise HR is moderately correlated with the exercise and postexercise HR at all ages in males and females. However, there is only a low correlation between either sitting or standing anticipatory HR and exercise and postexercise HR's. The HR's at 2′30” and 3′ during exercise are highly correlated as are the various postexercise HR's with each other at all ages and in both males and females. The correlation of the exercise HR and postexercise HR is moderately high. Percentile ranks for males and females (age 10–69) are given for the 1-minute postexercise HR's.     

‘Boys’ clubs are better than policemen's clubs': endeavours by philanthropists,social reformers,and others to prevent juvenile crime,the late 1800s to 1917

Conclusions set forth in Serious and Violent Juvenile Offenders (1997) and other recent reports are remarkably similar to those that men and women on both side of the Atlantic had made a century ago: prevention is better than punishment; stable families are important; schools and communities must take a role in providing positive experiences for children and youth. The Revd William Byron Forbush, sociologist Charles Zueblin, philanthropist Louise de Koven Bowen and scores of other men and women also believed that ‘structured playground activities’ and after-school recreation programmes were important interventions. Chicago's Hull-House, which was inspired by Toynbee Hall, had developed extensive educational and recreational offerings for the youth of its community by the 1890s. Scores of settlement houses, which numbered over 200 by 1904, and other private endeavours directed their energies and resources to such programmes before the First World War.     

Political Warfare in Helsinki: American Covert Strategy and the Union of Free Eastern European Sportsmen

When a group of East European exiles named the Union of Free Eastern European Sportsmen (UFEES) attempted to enter stateless athletes into the 1952 Helsinki Olympics, they executed a deliberate anti-communist manoeuvre. Perhaps more significantly, the UFEES was secretly funded by the U.S. government, a fact which serves to demonstrate the remarkable range of ways in which Washington was able to fund and work with private organisations and individuals in a ‘state-private network’ known only to those who were permitted access to it. This clandestine strategy of ‘political warfare’ was used to wage the Cold War at home and abroad, part of a veritable crusade against the perceived enemy of Soviet-style communism. Academics and contemporary onlookers have tended to view Helsinki as a forum for the Soviet Union's relentless campaign of propaganda which disparaged the West and elevated the Marxism of the East. This article endeavours to paint a different picture of the Helsinki Games, and argues that the U.S. government was also directing its covert political warfare apparatus towards the events in Finland.     

The empirical review of meta-analysis published in Korea

Meta-analysis is a statistical method that is increasingly utilized to combine and compare the results of previous primary studies. However, because of the lack of comprehensive guidelines for how to use meta-analysis, many meta-analysis studies have failed to consider important aspects, such as statistical programs, power analysis, publication bias, model selection, test of heterogeneity, and identification of heterogeneity. Therefore, the current study reviewed 84 meta-analysis studies conducted in Korea to examine proper application of the six categories named above. With regard to the issue of effect sizes, it was found that most of the meta-analysis studies obtained more than ten effect sizes, which seem to be an adequate number for representing an issue. However, many studies failed to consider the other issues: power analysis, publication bias, model selection, test of heterogeneity, and identification of heterogeneity.     

Networked Cultural Diffusion and Creation on YouTube: An Analysis of YouTube Memes

Web 2.0-based cultural diffusion occurs not only through viral word-of-mouth communication but also through Internet memes in which cultural consumers review, resemble, and recreate old cultural components, resulting in the creation of new cultural forms. YouTube features a platform for memetic creation with a host of user-generated parodies, reviews, and mashups derived from viral videos. This study examines the cultural ecosystem of YouTube memes inspired by Korean artist Psy’s viral production “Gangnam Style.” The study focuses on the salience of various genres of YouTube memes and structural connections between memetic videos. According to the results, the viral video of “Gangnam Style” sparked a sizable amount of user creativity, including remixes, parodies, self-directed performances, and reviews, among others. A network analysis of connections between memetic videos shows that various memetic genres drew different levels of audience attention and actions across various stages of the 3-month-long diffusion process. In addition, the content of the traditional mass media played a key role in giving the viral video wider publicity and acknowledgement, but this role was later shared by user-generated content.     

Beyond the ‘two cultures’ in the teaching of disaster: or how disaster education and science education could benefit each other

Abstract

Looking at the current discourse on how to teach disaster, one apparent gap is that the scientific aspect of disaster is discussed and taught mostly in isolation from its human aspect. Disaster educators seem to be primarily interested in addressing issues such as social vulnerability, community resilience, personal action-related knowledge and emotion rather than the scientific basis of disasters, whereas science educators often fail to make connections between the scientific accounts of disasters and the social and political contexts that surround them. In this theoretical paper, I claim that this disconnect is problematic and that overcoming it is a key to understanding and teaching disaster in a more nuanced and comprehensive manner. Drawing primarily on science and technology studies (STS) on disaster, I explore the potential of interpreting disasters as failures of socio-technical systems, which helps us unearth the inner workings of the complex network of science, technology and society in the wake of calamities. STS challenges the dichotomous understanding of the material and social worlds and takes a view that they shape each other to constitute socio-technical systems. Taking such an approach to disaster allows a synthetic understanding of the natural, technological and human-made disasters that we are faced with in the age of uncertainty and complexity. Based on the ideas of STS and examples of recent disasters in East Asian countries, I argue that disaster education and science education can cross-pollinate in tackling the post-disaster hardship and cultivating responsible citizens.     

Situating Special Educators’ Instructional Quality and Their Students’ Outcomes within the Conditions Shaping Their Work

This investigation examined relationships among special education teachers’ working conditions (e.g., classroom characteristics, administrative support), personal characteristics (e.g., experience, certification status, self-efficacy), instructional quality, and students with disabilities’ reading achievement and behavioral outcomes. Data from the 2004–2005 administration of the Special Education Elementary Longitudinal Study were used. Confirmatory factor analysis was used to test the fit of models for five latent factors. Hybrid structural models were applied to test the hypothesis that working conditions would be positively associated with special education teachers’ self-efficacy and their instructional quality, which would, in turn, be positively associated with their students’ reading achievement and behavioral outcomes. Although the initial structural equation model tested failed to support the hypotheses, several significant relationships with theoretical and practical significance were discovered. Directions for future research and practical implications are discussed.