Effects of age and physical activity on response speed in knee flexor and extensor muscles

This study aims to determine the normalized response speed (V _rn) in vastus lateralis (VL) and biceps femoris (BF) muscles in different age groups using tensiomyography. Eighty-four male subjects were divided into four age groups: teenage subjects (T); undergraduate students (U), adult subjects (A), and the elderly group (E). Differences in V _rn were observed between E and T (p?=?0.000), E and U (p?=?0.000), and E and A (p?=?0.018) for right VL and between E and T (p?<?0.000) and U (p?=?0.003) for left VL; between T and U (p?=?0.010) and A (p?=?0.000) for right VL, and A (p?=?0.004) for left VL. V _rn in the BF displayed different behavior from that of the VL, increasing moderately or stabilizing and declining slightly in E, in right leg (p?=?0.020). The data obtained highlighted a decline in V _rn for the VL in both legs with increasing age and, declines in BF response speed were observed only in E.     

Land,territory and commons: voices and visions from the struggles

ABSTRACT

All over the world, financial capitalism and extractivism are appropriating land as if it was nothing more than a commodity, a mere ‘factor’ of production that can be exploited to generate financial returns. Movements and activists are organizing, resisting, protecting and promoting life-giving visions against this continuous enclosure of living beings and paces: they use their bodies, laws, educational projects, histories and visions to regain control over territory as a political space, self-determine and create solidarities. In the act resistance, they are the target of moral, physical and legal violence. They and their ideas are criminalized, disciplined, punished and in some cases exterminated. In this contribution, activists from the Basque Country, Guatemala, Kenya and the Six Nations and a group of academics get together to learn from each other, support the ongoing search for common vocabularies and identify possible milestones of a coordinated and international strategy for a life-enhancing future.     

Evaluating positive leadership: pilot study on the psychometric properties of a reduced version of the Positive Leadership Assessment Scale / Evaluando el liderazgo positivo: estudio piloto de las propiedades psicométricas de una versión reducida del Positive Leadership Assessment Scale

Positive leadership is considered a fundamental factor which contributes significantly to the development of healthy organizations. Positive leadership has been address via other leadership models, primarily transformational and authentic leadership, with which some affinities have been established. Although there is a large body of literature on positive leadership, especially related to its practical aspects, the construct is not properly delimited and there are only a few relevant contributions on how to measure it. The purpose of this paper is to conduct a pilot study to examine the psychometric properties of a reduced version of the PLAS (Positive Leadership Assessment Scale). Results from a confirmatory factorial analysis show that a five-correlated factors model achieves a good fit with the empirical data (on a sample of Spanish students). Likewise, this study also offers a range of evidence of validity, showing a relationship with the constructs of both transformational and authentic leadership and engagement.     

Bayesian Analysis of Multiple Hypothesis Testing with Applications to Microarray Experiments

Recently, the field of multiple hypothesis testing has experienced a great expansion, basically because of the new methods developed in the field of genomics. These new methods allow scientists to simultaneously process thousands of hypothesis tests. The frequentist approach to this problem is made by using different testing error measures that allow to control the Type I error rate at a certain desired level. Alternatively, in this article, a Bayesian hierarchical model based on mixture distributions and an empirical Bayes approach are proposed in order to produce a list of rejected hypotheses that will be declared significant and interesting for a more detailed posterior analysis. In particular, we develop a straightforward implementation of a Gibbs sampling scheme where all the conditional posterior distributions are explicit. The results are compared with the frequentist False Discovery Rate (FDR) methodology. Simulation examples show that our model improves the FDR procedure in the sense that it diminishes the percentage of false negatives keeping an acceptable percentage of false positives.     

An Index of Child Health in the Least Developed Countries (LDCs) of Africa

In this article we present a new composite index of child health, applied to the Least Developed Countries (LDCs) of Africa, one of the areas of the planet most castigated by poverty. Our index has been constructed attending to the variables defined in the Goals of the Millennium Declaration. For this purpose we will use the P₂ distance method for the year 2008, the last year for which data are available. This index integrates variables of child health that permit a territorial ordering of the LDCs of Africa, in terms of those partial indicators.     

On the manipulation of social choice correspondences

Duggan and Schwartz (Soc Choice and Welfare 17: 85–93, 2000) have proposed a generalization of the Gibbard–Satterthwaite Theorem to multivalued social choice rules. They show that only dictatorial rules are strategy-proof and satisfy citizens sovereignty and residual resoluteness. Citizens sovereignty requires that each alternative is chosen at some preference profile. Residual resoluteness compels the election to be single-valued when the preferences of the voters are “similar”. We propose an alternative proof to the Duggan and Schwartz’s Theorem. Our proof highlights the crucial role of residual resoluteness. In addition, we prove that every strategy-proof and onto social choice correspondence concentrates the social decision power in the hands of an arbitrary group of voters. Finally, we show that this result still holds in a more general framework in which voters report their preferences over sets of alternatives.     

The relationship between leisure and life satisfaction: application of activity and need theory

The purpose of this study was to better understand the complex relationship between leisure and life satisfaction. Components of two distinct, but potentially integrative, theoretical frameworks (i.e., activity theory and need theory) predicting the relationship between leisure and life satisfaction were tested with a sample of residents from a Midwestern community (n = 633). Findings provided support for both theoretical perspectives, but stronger relationships were found between satisfied needs than with participated activities. In spite of these findings, the various inconsistencies within the two theoretical frameworks suggest that future research is needed.     

Nonparametric Methods in Continuous Time Model Specification

Some popular parametric diffusion processes have been assumed as such underlying diffusion processes. This paper considers an important case where both the drift and volatility functions of the underlying diffusion process are unknown functions of the underlying process, and then proposes using two novel testing procedures for the parametric specification of both the drift and diffusion functions. The finite-sample properties of the proposed tests are assessed through using data generated from four popular parametric models. In our implementation, we suggest using a simulated critical value for each case in addition to the use of an asymptotic critical value. Our detailed studies show that there is little size distortion when using a simulated critical value while the proposed tests have some size distortions when using an asymptotic critical value in each case.