Antioxidant Status and Oxidative Stress in the Circulation of Younger and Elderly Human Subjects

Extensive research has demonstrated the protective properties of antioxidants, which scavenge reactive oxygen species and their precursors, as well as up-regulate enzymes involved in the repair of cellular damage. Several case–control studies have showed higher blood levels of antioxidants and decreased oxidative stress in younger individuals when compared with older ones. Cell damage caused by free radicals appears to be a major contributor in aging and degenerative diseases of aging such as cancer, cardiovascular disease, cataracts, compromised immune system, rheumatoid arthritis and brain dysfunction. The objective of this study was to determine the variation of Circulating levels of selected antioxidants (enzymic and non enzymic) and oxidative stress marker in younger and older humans. The results showed that a majority of the younger age group participants showed a significant increase in enzymic and nonenzymic antioxidant status and a decrease in oxidative stress when compared with the older age group.     

DACs: Bringing direct access to variable-length codes

We present a new variable-length encoding scheme for sequences of integers, Directly Addressable Codes (DACs), which enables direct access to any element of the encoded sequence without the need of any sampling method. Our proposal is a kind of implicit data structure that introduces synchronism in the encoded sequence without using asymptotically any extra space. We show some experiments demonstrating that the technique is not only simple, but also competitive in time and space with existing solutions in several applications, such as the representation of LCP arrays or high-order entropy-compressed sequences.     

The implication of formal educational activities in old age and its relation to psychosocial indicators / La implicación en actividades educativas formales en la vejez y su relación con indicadores psicosociales

This study analyses some psychosocial dimensions (level and type of activity, self-perceived health, self-efficacy in relation to ageing and social support) in non-dependent older people. The sample comprises students of a university programme for older people (PUM) as well as older people who did not participate in the educational activity. Results show similarities and differences between both groups; namely, the older people on the PUM programme were more physically active and participated more in formal activities. Three profiles of older people were identified: a less active group, with lower scores in the indicators assessed; a second group who were socially active, particularly at a family level, with intermediate levels in the dimensions analysed; and a third group who were very active at a formal level (principally made up of the PUM students) and with the best self-efficacy indices in relation to ageing and self-perceived health. Involvement in formal educational activities is related to more satisfactory and positive profiles in old age, and is a highly relevant resource for the promotion of well-being at this stage of life.     

Precarious privilege: Indignad@s,daily disidentifications,and cultural (re)production

In this article, I develop the notion of precarious privilege to investigate dialectics of cultural (re)production, in relation to both specific discursive practices and broader discursive formations. Using the Indignad@s social movement as an example, I locate, interpret, and critique a series of disidentification dynamics shaping the movement as a whole, as well as the rhetoric of specific participants. Regarding the rise and development of Indignad@s, precarious privilege illuminates a conflicted social position enabled by disidentification from the current crisis of neoliberalism in Western Europe—a conjuncture that the movement strives to both expose and exploit. As for the views expressed by specific activists, precarious privilege helps explain the discursively enacted disidentification from the imagined aspects of their and others’ (supra)national cultural identities. Grounded in this analysis, I emphasize the potentiality but also the limitations of this generalized tension between residual and emergent dynamics shaping Indignad@s’ political practices.     

Mathematics learning and practice in and out of school: A framework for connecting these experiences

A variety of researchers in the last fifteen years have described how people learn and use mathematics in out-of-school situations. These researchers have found that mathematics learning and practice in and out of school differ in a number of ways. In this paper we examine and discuss these differences while maintaining the position that while some differences may be inherent, many differences can be narrowed so that mathematics learning and practice in school and out of school can build on each other and be connected. Before discussing a framework that we think sheds some light on connecting these experiences, we present some research from several of our studies that illustrates some of the differences between in-school and out-of-school mathematics practice and lays the groundwork for the discussion of the framework.We then discuss Saxe's (1991) research framework for gaining insight into the interplay between sociocultural and cognitive development processes through the analysis of practice participation (p. 13). Although Saxe's framework is a method for studying the interplay between sociocultural and cognitive development processes, we propose that it may be helpful in working towards connecting in-school and out-of-school mathematics learning and practice. Thus, we discuss the framework with illustrations from our own research, and then elaborate on ways to make this interplay between in-school and out-of-school contexts more deliberate.     

Family Predictors of Maternal and paternal Involvement in Programs for Young Children with Disabilities

The study of family variables has become increasingly critical in understanding outcomes typically considered program driven. Research linking family variables to parental involvement in early intervention programs for young children with disabilities is generally lacking. The purpose of this study was to determine the combined influence and predictive ability of family characteristics on maternal and paternal involvement in early intervention programs. Service providers rated mothers' and fathers' involvement in early intervention programs Mother and fathers completed a battery of self-report questionnaires related to a variety of constructs, such as family functioning, marital adjustment, social supports, stress, coping, and parental involvement. Structural equating modeling was used to test the predictive ability of family variables. Two different models were developed for mothers and fathers. Results indicated significant outcomes for both group, largely supporting the proposed model. The coping variable emerged as a significant predictor of maternal and paternal involvement as well as a mediator variable between family functioning and parental involvement.     

Psychometric analysis of a scale for assessing specific competences in tutoring and educational guidance / Análisis psicométrico de una escala para evaluar las competencias específicas en tutoría y orientación educativa

The aim of this study is to validate an instrument for assessing self-perceived tutoring and educational guidance competences in students on the Master’s in Teaching. A historical review of secondary school teacher training shows the need to provide evidence of students’ competence levels. In view of this, a scale has been designed based on the specific competences they ought to acquire. A total of 336 students from the University of Salamanca and Oviedo participated in the study. An exploratory and confirmatory factor analysis of the results of the psychometric test show the good fit of the model globally (RMR = .075; GFI = .969) and incrementally (AGFI = .964; NFI = .960; RFI = .957), thus confirming the validity and reliability of the instrument. Finally, the study concludes by emphasizing the need to study real and self-perceived competence levels in specific areas, and to design suitable instruments to measure these levels.     

Do Spanish secondary school teachers really value different sorts of procedural skills?

The aim of teaching science at secondary school level is that of achieving the scientific literacy of all citizens. This must involve diverse objectives, among which may be found the development of procedural skills (thought, manipulative, communicative, etc.). The new curricula of many countries provide for these objectives. However, it is important to know to what extent the teaching staff consider them as true content to be taught. In this article, we analyse the opinions of secondary school teachers belonging to schools in north‐western Spain with regard to how they value different types of procedures. Our findings show that the surveyed teachers establish differences between various procedural skills as far as the recognition of their presence in the classroom and their evaluation are concerned, although it may be said that they generally value procedural skills highly. These findings are discussed. In addition, the persistence of traditional conceptions in the teaching of science, as well as the difficulty of assuming that the changes promoted by new curricular approaches are addressed, are highlighted.     

Benefits of achieving vigorous as well as moderate physical activity recommendations: Evidence from heart rate complexity and cardiac vagal modulation

Abstract

The aim of this study was to examine differences in traditional heart rate variability measurements and heart rate complexity (sample entropy) in young adults grouped by objectively measured achievement of either moderate or both moderate and vigorous physical activity recommendations. Of 168 young adults tested (86 females, 82 males; age 20.5 ± 1.2 years), 119 achieved only recommendations for moderate physical activity (moderate group) and 49 achieved recommendations for both moderate and vigorous physical activity (vigorous group). Analysis of covariance controlling for sex, weekly minutes of moderate physical activity, and percentage of body fat was used to assess between-group differences in heart rate variability and heart rate complexity. Logistic regression analysis was used to determine the group characteristics that best predicted high heart rate complexity and vagal indices of heart rate variability. The majority of the autonomic measures were higher (P < 0.05) in the vigorous group, and regression analysis showed that vigorous physical activity was the only multivariate predictor of higher heart rate complexity and higher heart rate variability. Young adults engaged in regular vigorous physical activity were more than twice as likely to have high heart rate complexity than those involved in predominantly moderate exercise. These findings suggest that vigorous physical activity is more closely associated with high heart rate complexity than moderate physical activity in young adults.     

水下蝶泳打腿技术的理论与实践——运动学特征,涡流的产生以及在出发、转身、划水过程中的应用

从理论上介绍了鱼类摆尾技术的流体力学研究成果,并在实践中与运动员蝶泳腿技术分析相结合,指出水下蝶泳打腿(UUS,亦称水下波动游泳)的运动学、动力学特征以及在游泳出发、转身和划水过程中的应用.