Carnosine in health and disease

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.     

EFFECTS OF TEACHER–STUDENT RELATIONSHIPS ON PEER HARASSMENT: A MULTILEVEL STUDY

Peer harassment is a major social problem affecting children and adolescents internationally. Much research has focused on student‐to‐student harassment from either an individual or a multilevel perspective. There is a paucity of multilevel research on students’ relationships with the classroom teacher. The purpose of this study was to use a socioecological perspective to examine the relationships between individual student‐level characteristics, problematic teacher–student relationships, and student‐reported peer harassment. A total of 1,864 children (50.7% female) aged 8 to 13 years (M = 9.82, SD = 1.24), nested in 27 schools (58.2% public) in Spain, participated in the study. Ninety‐four homeroom teachers reported on teacher–student relationships, and students completed self‐report measures related to peer harassment and teacher–student relationships. Multilevel models showed that relationships between students and teachers exerted a varying degree of influence on classroom levels of peer harassment. Specifically, student‐reported teacher support was associated with diminished student‐reported peer victimization, whereas direct and indirect student‐reported teacher‐to‐student aggression was associated with increased peer victimization. Additionally, student‐reported student‐to‐teacher aggression and teacher‐to‐student aggression were associated with increased student‐reported peer aggression. Teacher‐reported variables at the classroom level, however, contributed little to student‐reported outcomes. Results are discussed in the context of future research on relationships between teachers and students.     

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

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.     

Effects of Different Chair-Based Exercises on Salivary Biomarkers and Functional Autonomy in Institutionalized Older Women

Purpose: The aim of this study was to test the effects of chair-based exercise programs on salivary stress hormones, physical fitness, and functional autonomy of institutionalized older women. Method: In total, 47 participants (80 ± 8.04 years old) were recruited and allocated into three groups: chair-based aerobic exercises (CAE, n = 19), chair-based elastic-band strength exercises (CSE, n = 15), and a control group (CG, n = 13). A 14-week exercise intervention was done for the CAE and CSE groups, two times per week, in no consecutive days. Members of the CG did not participate in any type of exercise but kept their regular lifestyle. Fear of falling, autonomy, physical fitness, salivary cortisol, and alpha-amylase levels were assessed before and after the intervention. Results: The CAE group improved upper and lower body strength, agility–dynamic balance, and autonomy, with fear of falling decreasing significantly (p < .05, moderate effect size). Both exercise groups showed a trend toward an increase in salivary alpha-amylase levels (CAE = 43%, d = .31, and CSE = 44%, d = .41). Conclusion: Both exercise programs were able to improve functional autonomy, even in elders older than 80 years of age. It might be interesting to investigate the effectiveness of combining both aerobic and strength exercises in a unique protocol. The modulation effect of exercise in the hormonal responses needs to be further explored.     

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

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.     

Gender,Science and Technology in Brazil

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.     

Analysis of integrated STATCOM-SMES based on three-phase three-level multi-pulse voltage source inverter for high power utility applications

This paper is aimed to investigate the operating characteristics of a static synchronous compensator (STATCOM) integrated with superconducting magnetic energy storage (SMES) for high power applications in the transmission network level. The STATCOM controller topology comprises multi-level multi-pulse neutral-point clamped-type (NPC) voltage source inverters (VSIs) using the harmonics cancellation technique, and incorporates a SMES coil. An innovative two-quadrant multi-level dc-dc converter is proposed to effectively interface the STATCOM with the superconducting coil using a buck-boost topology with neutral point voltage control capabilities; thus enabling to simultaneously control both active and reactive power exchange with the high voltage power system. A detailed analysis of major system variables is presented, including analytical results and digital simulations using the MATLAB/Simulink environment. Moreover, a three-level control scheme is designed, including a full decoupled current control strategy in the d-q reference frame with a novel controller to prevent the STATCOM dc bus capacitors voltage drift/imbalance and an enhanced power system frequency controller.     

Lenguaje y rendimiento escolar: Un estudio predictivo

La incidencia de las competencias lingüistícas del escolar sobre las adquisiciones escolares en las demás áreas del currículum es una realidad que todos los maestros pueden comprobar día a día. En este trabajo se investiga esa incidencia, medida a través de la variable fracaso escolar, y sus resultados podrían permitir extraer algunos principios de intervención educativa precoz en algunos aspectos del lenguaje cruciales para la escolaridad posterior.     

The ‘invention’ of FIFA history: João Havelange’s election to FIFA presidency as a historic event

ABSTRACT

In 1974, the Brazilian sports official João Havelange was elected FIFA’s president in a two-round election, defeating the incumbent Stanley Rous. The upset, often attributed to a successful alliance with Asia, the Middle East and Africa, what at the time was referred to as the Third World – surprised observers everywhere. Here, the election can be analysed as a historically relevant event of social significance. It can be thought of as a political window by means of which the international dynamic of a specific moment in the Cold War can be perceived, especially the limitations and potentialities of the agency available to periphery countries at that time. In this article, I intend to discuss the narratives that forged the history of FIFA, which take this political ‘event’ as a key in the institution’s own historical transformation. The sources analysed will be mainly FIFA official histories, such as the FIFA News, FIFA historical books and movies about the history of FIFA.     

Evolution and Creationism: Views of Students in a Colombian University—Findings from 7 Years of Data Using a Three-Question Survey

Research in Science Education - The theory of evolution is the backbone of the biological sciences. Arguably, this is the reason why evolution education is an extensively investigated issue in...