Creatine supplementation does not decrease oxidative stress and inflammation in skeletal muscle after eccentric exercise

Abstract

Thirty-six male rats were used; divided into 6 groups (n = 6): saline; creatine (Cr); eccentric exercise (EE) plus saline 24 h (saline + 24 h); eccentric exercise plus Cr 24 h (Cr + 24 h); eccentric exercise plus saline 48 h (saline + 48 h); and eccentric exercise plus Cr 48 h (Cr + 48h). Cr supplementation was administered as a solution of 300 mg · kg body weight^?1 · day^?1 in 1 mL water, for two weeks, before the eccentric exercise. The animals were submitted to one downhill run session at 1.0 km · h^?1 until exhaustion. Twenty-four and forty-eight hours after the exercise, the animals were killed, and the quadriceps were removed. Creatine kinase levels, superoxide production, thiobarbituric acid reactive substances (TBARS) level, carbonyl content, total thiol content, superoxide dismutase, catalase, glutathione peroxidase, interleukin-1b (IL-1β), nuclear factor kappa B (NF-kb), and tumour necrosis factor (TNF) were analysed. Cr supplementation neither decreases Cr kinase, superoxide production, lipoperoxidation, carbonylation, total thiol, IL-1β, NF-kb, or TNF nor alters the enzyme activity of superoxide dismutase, catalase, and glutathione peroxides in relation to the saline group, respectively (P < 0.05). There are positive correlations between Cr kinase and TBARS and TNF-α 48 hours after eccentric exercise. The present study suggests that Cr supplementation does not decrease oxidative stress and inflammation after eccentric contraction.     

The emerging of teachers' conceptions of new subjects inserted in mathematics programs: the case of informatics

The changes in mathematical curricula induced by the introduction of informatics in school represent the general framework of this research. In particular we focus on the teacher's role by analysing the different choices taken by mathematics teachers when faced with a curriculum reform induced by the introduction of informatics in secondary school courses (age 14–16). Our hypothesis is that these choices are the consequence of conceptions teachers have about informatics and its teaching in relation to the teaching of mathematics. Thus, through a case study research method, we focus on mathematics teachers' conceptions of informatics and its teaching. An attempt is made at outlining a typology of these conceptions, based on the different orientations identified.     

What Are They Thinking? Automated Analysis of Student Writing about Acid–Base Chemistry in Introductory Biology

Students' writing can provide better insight into their thinking than can multiple-choice questions. However, resource constraints often prevent faculty from using writing assessments in large undergraduate science courses. We investigated the use of computer software to analyze student writing and to uncover student ideas about chemistry in an introductory biology course. Students were asked to predict acid-base behavior of biological functional groups and to explain their answers. Student explanations were rated by two independent raters. Responses were also analyzed using SPSS Text Analysis for Surveys and a custom library of science-related terms and lexical categories relevant to the assessment item. These analyses revealed conceptual connections made by students, student difficulties explaining these topics, and the heterogeneity of student ideas. We validated the lexical analysis by correlating student interviews with the lexical analysis. We used discriminant analysis to create classification functions that identified seven key lexical categories that predict expert scoring (interrater reliability with experts = 0.899). This study suggests that computerized lexical analysis may be useful for automatically categorizing large numbers of student open-ended responses. Lexical analysis provides instructors unique insights into student thinking and a whole-class perspective that are difficult to obtain from multiple-choice questions or reading individual responses.     

Next Generations,Catwalks, Random Walks and Arms Races: conceptualising the development of quality assurance schemes

The emergence and development of quality assurance schemes in European countries over the last 15–20 years has inspired many national case studies of the systems and procedures adopted. The methods, contexts, and procedures associated with this policy change are diverse. But although individual countries have set about changing policy in different ways there appear to be some common developmental patterns within the Europe of the Bologna Process. How can these developments be conceptualised? In a first step this paper advances a typology based on the quality assurance literature. In a second step, the paper applies the typology to quality assurance developments in three countries. The third part of the paper discusses the strengths and weaknesses of the modelling approach in the light of the empirical evidence and a political science analysis of policy change. The paper concludes with a discussion on future directions for the comparative study of policy change within the European Higher Education Area on the basis of this conceptualisation of developments in quality assurance policy.     

Influences of developmental contexts and gender differences on school performance of children and adolescents

This study investigated children and adolescents’ school performance over time focusing on two variables that may influence it: developmental context and gender. The sample comprised 627 participants (M_age?=?11.13, SD?=?1.8), 51% of them female, from grade one to eight, living either with family (n?=?474) or in care institutions (n?=?153). Participants answered individually the Teste de Desempenho Escolar (School Performance Test) and the Structured PRONEX Interview. Findings indicated a main effect of time on school performance (i.e., writing, reading and arithmetic). Furthermore this main effect was further qualified by a time and developmental context interaction and by a time and gender interaction. Interactions revealed that the participants from care institutions attained more significant increases in writing and reading than participants living within a family context; and that girls attained more significant increases in writing than boys. Therefore, school performance progress appears as affected by developmental contexts and gender. The findings reveal how school performance needs to be observed as a multidimensional variable, affected by individual characteristics but also by external ones.     

Trends in Environmental Education Images of Textbooks from Western and Eastern European Countries and Non-European Countries

Textbook analysis is seen as a major element for studying environmental education addressing pupils, image analysis being rather relevant when studying textbooks written in 11 languages. We analysed 25 textbooks from 14 countries addressed to 14–16-year-old pupils, focusing on: (1) local and foreign/global images; (2) urban/rural and nature images; (3) negative impact, human management, and the beauty of nature; and (4) men and women in images with negative and positive impact. We distinguished some trends between Western (WEc) and Eastern (EEc) European countries and non-European countries (NEc). In contrast to textbooks from EEc and NEc, which tend to show the beauty of nature with little human influence, WEc textbooks tend to exhibit more images of urban/rural landscape, of human negative impact and of human management, expressing an anthropocentric view of the environment. Men are usually more present in textbook images than women. However, some images exhibiting more women than men could be found in textbooks from WEc and EEc, but never in NEc. In negative impact pictures, men are more often present than women but NEc women are never present in such images. Women are more frequent than men in positive impact images. Results suggest that textbooks from EEc and NEc should give more emphasis to human management and urban/rural images, whereas those from WEc should give more attention to the beauty of nature. A balance in the presence of men and women in images should be a matter of greater concern by all textbooks’ authors and publishers.     

Las capacidades gramaticales en el desarrollo

Resumen

Mediante tareas de clasificación de segmentos-palabra, se investiga la evolución infantil en la reflexión sobre el propio idioma (capacidad gramatical). Los datos demuestran que esta evolución pasa por largos períodos—entre ocho y once años—de estrategias semántico-pragmáticas y, por tanto, inmaduras gramaticalmente.