The relative age effect on physical fitness in preschool children

ABSTRACT

The aim of the present study was to investigate the existence of a relative age effect (RAE) on physical fitness of preschoolers. Anthropometry and physical fitness were assessed in 3147 children (3–5 years old) using the PREFIT battery. Based on the birth year, participants were divided into 3year groups (3-, 4- and 5-years). Within each year group, 4quarter groups were created: quarter 1, preschoolers born from January to March; quarter 2, from April to June; quarter 3, from July to September; quarter 4, from October to December. The MANCOVA analysis revealed a main effect of year group (Wilks’ λ = 0.383; F_10,5996 = 369.64; p < 0.001, η_p ² = 0.381) and of quarter (Wilks’ λ = 0.874; F_15,8276.6 = 27.67; p < 0.001; η_p ² = 0.044) over the whole battery of tests. To the best of our knowledge, this is the first study to report the existence of RAE at the preschool stage. In general, performance improved as the relative age increased (i.e., those born in quarter 1 performed better than those in the other quarters). Individualization strategies should be addressed within the same academic year not only in elementary or secondary years but also in preschoolers.     

Timescales for exploratory tactical behaviour in football small-sided games

The aim of this study was to identify the dynamics of tactical behaviour emerging on different timescales in football small-sided games and to quantify short- and long-term exploratory behaviour according to the number of opponents. Two teams of four professional male footballers played small-sided games against two different teams with a variable number of opponents (3, 5 and 7). Data were collected using a combination of systematic observation and a non-differential global positioning system (15 Hz). The temporal diversity and structural flexibility of the players were determined by calculating the dynamic overlap order parameter q, entropy and trapping strength. Analysis of the exploratory dynamics revealed two different timescales, forming a different metastable landscape of action for each constraint. Fast dynamics lasted on average a few seconds and consisted of changes in tactical patterns. The long timescale corresponded to the shared tasks of offence and defence lasting tens of seconds. The players’ tactical diversity decreased with an increasing number of opponents, especially in defence. Manipulating numerical imbalance is likely to promote changes in the diversity, unpredictability and flexibility of tactical solutions. The fact that the temporally nested structure of constraints shaped the emergence of tactical behaviour provides a new rationale for practice task design. The manipulation of numerical imbalance on the timescale of a few tens of seconds, on which the exploratory behaviour of players saturates, may help coaches to optimise the exploratory efficiency of the small-sided games.     

Innovative moments and narrative change in career counselling: a case study

International Journal for Educational and Vocational Guidance - This case study of an undecided university student has two aims: to assess the effect of life design career counselling on...     

Educational knowledge generation from administrative data

Most universities use Information Systems (IS) to perform their daily administrative activities (student enrollment, data files, accountancy, etc.), and an integrated Learning Management System (LMS) to support teaching and learning. However, although a lot of effort has been put into deploying these computerized systems, the data that they provide are not fully exploited from an educational perspective. In this paper we describe a case in which these data have been used to identify relevant relations between the general use of the LMS, the existence of teaching innovation programs and the quality of education. The method used can be easily generalized and employed in other different contexts, to derive meaningful information on the impact that some variables may have over others.     

The building of weak expertise: the work of global university rankers

University rankers are the subject of much criticism, and yet they remain influential in the field of higher education. Drawing from a two-year field study of university ranking organizations, interviews with key correspondents in the sector, and an analysis of related documents, I introduce the concept of weak expertise. This kind of expertise is the result of a constantly negotiated balance between the relevance, reliability, and robustness of rankers’ data and their relationships with their key readers and audiences. Building this expertise entails collecting robust data, presenting it in ways that are relevant to audiences, and engaging with critics. I show how one ranking organization, the Times Higher Education (THE), sought to maintain its legitimacy in the face of opposition from important stakeholders and how it sought to introduce a new “Innovation and Impact” ranking. The paper analyzes the strategies, methods, and particular practices that university rankers undertake to legitimate their knowledge—and is the first work to do so using insights gathered alongside the operations of one of the ranking agencies as well as from the rankings’ conference circuit. Rather than assuming that all of these trust-building mechanisms have solidified the hold of the THE over its audience, they can be seen as signs of a constant struggle for influence over a skeptical audience.     

Huelga Schools in Houston: Community-Based Education in the Struggle for Legal Recognition, 1970

This essay provides an overview of the huelga schools established in Houston, Texas, in 1970. For 2 years, from 1970 to 1972, the Mexican American community opposed the Houston Independent School District’s plan to integrate the schools by pairing so-called White Mexican Americans with African American students. While they protested this decision, Mexican Americans also established huelga or strike schools in order to provide their children with basic skills in education and to explain the meaning and significance of their political actions. This is the history of the huelga schools established in the 1st months of this struggle.     

Effects of vanadate supplementation on high fat-diet and diabetes-induced metabolic changes in liver

Normal and streptozotocin-induced diabetic rats were fed the control high starch-diet or a high fatdiet supplemented with or without sodium orthovanadate (1.5 mg/g diet) for six weeks. Plasma glucose, insulin and triacylglycerol levels and the activities of hepatic glycogen synthase, phosphorylase, glucose-6-phosphate dehydrogenase, malic enzyme, and ATP-citrate lyase were measured in these eight groups of rats. The high fat-diet increased the levels of insulin (P<0.05) and triacylglycerol (P<0.01) in plasma and decreased the activities (P<0.001) of phosphorylase (active from and total) and the lipogenic enzymes. Vanadate supplementation led to significant (P<0.001) decreases in the elevated insulin and triacylglycerol levels whereas the enzyme activities remained unaffected. Diabetes and fat diet in combination caused 3.7-fold increases in plasma glucose and triacylglycerol levels and vanadate decreased them by 58% and 74% respectively. Vanadate improved the activities of hepatic glycogen metabolizing and lipogenic enzymes in diabetic rats when they were fed on control starch-diet but not with high fat-diet. This study shows that vanadate normalizes hyperinsulinemia and hypertriglyceridemia but not the defective hepatic glycogen metabolism in high fat-fed rats.     

Delinking rhetorics of neoliberalism: An analysis of South American leftist presidents’ speeches

We analyze the so-called Socialism of the twenty-first century in which nine South American governments turned to the left over the last 15 years. This South American socialist turn is seen as a delinking from the logics of dependency and pure neoliberalism. To explore the rhetorics that underlie this delinking process, we conducted both a macroanalysis and an intradiscursive rhetorical analysis of the inauguration and most significant speeches of all of the leftist South American presidents elected after 1999. We claim that a common critique of neoliberalism underlies the South American presidents’ speeches, which manifests through specific rhetorics concerning participatory democracy, social inclusion, and environmental protection. When they became transnational, these delinking rhetorics crafted a decolonial critique that calls for more indigenous models of development.