Optimal representative sample weighting

Statistics and Computing - To overcome the inherent limitations of axis-aligned base learners in ensemble learning, several methods of rotating the feature space have been discussed in the...     

The Culture of High-Risk Alcohol Use Among Club and Intramural Athletes

Abstract

Objective: The purpose of this study was to examine the drinking patterns of club and intramural college athletes and compare their alcohol consumption, perceived norms around the excessive use of alcohol, experience of negative consequences, and employment of protective strategies with those of campus varsity athletes. Participants: A total of 442 undergraduate students attending a private, suburban institution in the Northeast participated in the American College Health Association National College Health Assessment-II Web survey in spring 2011. Thirty-five students identified themselves as varsity athletes, 76 identified as club sport athletes, and 196 students identified themselves as intramural athletes. Methods: Survey responses were analyzed using Statistical Package for the Social Sciences. The Pearson's correlation coefficient and test for independence were applied to identify significant relationships between athlete status and identified variables related to alcohol use. Results: Results indicated that there were significant correlations between athlete status and all variables, to varying degrees. Conclusions: These findings have implications for campus health promotion professionals and athletics program coordinators seeking to address high-risk alcohol use among college athletes.     

The Eating Disorders NOS Diagnostic Profile Among College Women

Abstract

The authors examined a proposed profile of eating-related behaviors, associated features, developmental issues, and help-seeking behavior among college women, using an eating disorder response program. The most common symptom scenario was a pattern of regular binge eating, together with daily exercise and occasional purging. The most common associated features were distressing or dysfunctional overconcern about body image and self-esteem, usually with day-to-day stress and intermittent depression. The women who fit this pattern also presented developmental issues of perfectionism, conflictual relationships with parents, and struggles for independence; and they tended to be ambivalent about seeking services. Implications for practice, including the need to develop a framework for eating disorder responses on campus that includes preventive programs and developmental interventions to target emerging and moderate concerns are discussed; limitations and the preliminary nature of the findings are explicated.     

Intensive management reduces butterfly diversity over time in urban green spaces

Urban Ecosystems - Loss and fragmentation of semi-natural grasslands have had negative consequences for grassland biodiversity, such as butterflies. Urban parks and other urban green spaces have so...     

A Multidimensional Approach to Precarious Employment Among Young Workers in EU-28 Countries

This article uses a new multidimensional indicator to measure precariousness among young workers across all EU-28 countries. This indicator measures both the incidence and intensity of precariousness. The analysis has involved five dimensions: wages, type of contract, type of working day, disempowerment, and job insecurity. Our database is the European Union Labour Force Survey for the period 2009–2016. The main indication of precariousness is low wages. We find high rates of precariousness for Mediterranean countries (because of low wages and temporary contracts), Denmark (low wages), and the Netherlands (expansion of involuntary part-time jobs). Central European countries have moderate rates, and most Continental and Eastern countries have low rates. We also find that a higher level of education is related to a lower probability of having a precarious job. Finally, we find a greater probability of having a precarious job among women in most countries, and non-statistically significant differences by country of birth.

     

Fast parallel $$\alpha $$-stable distribution function evaluation and parameter estimation using OpenCL in GPGPUs

\(\alpha \)-Stable distributions are a family of probability distributions found to be suitable to model many complex processes and phenomena in several research fields, such as medicine, physics, finance and networking, among others. However, the lack of closed expressions makes their evaluation analytically intractable, and alternative approaches are computationally expensive. Existing numerical programs are not fast enough for certain applications and do not make use of the parallel power of general purpose graphic processing units. In this paper, we develop novel parallel algorithms for the probability density function and cumulative distribution function—including a parallel Gauss–Kronrod quadrature—, quantile function, random number generator and maximum likelihood estimation of \(\alpha \)-stable distributions using OpenCL, achieving significant speedups and precision in all cases. Thanks to the use of OpenCL, we also evaluate the results of our library with different GPU architectures.     

Influence of urbanization on the occurrence and activity of aerial insectivorous bats

Activity and species-specific responses of insectivorous bats in different urban-forest conditions provides a general perspective on the adaptability and vulnerability of bat species towards urbanization intensity. Here we evaluated species richness and activity patterns of aerial insectivorous bats across an urbanized landscape in the highlands of Chiapas, in Mexico. Acoustic monitoring of echolocation calls was conducted for 27 nights over a period of four months. Species richness and relative activity of insectivorous bats were estimated in a landscape with different conditions of urbanization intensity: urban areas, non-urban and forest areas. We identified a total of 14 bat species and three phonotypes. Bat species richness and relative activity was similar (X² = 0.568, gl = 2, p > 0.05), but species composition differed among conditions. We observed a significant higher occurrence of Bauerus dubiaquercus, Eptesicus brasiliensis and Myotis californicus in forest sites. Urban sites presented higher occurrence of Molossus rufus and phonotype Molossidae 2, while non-urban sites presented a higher occurrence of Eptesicus furinalis and phonotype Molossidae 2. We were able to identify bat species according to their relative activity in relation todifferent landscape conditions. Species of the Molossidae family presented the highest activity in urban sites, which was positively affected by the number of streetlights, while species of the Vespertilionidae presented the highest activity in forest sites, which was positively related totree density. While urbanization tends to diminish native biodiversity and alter faunal communities, our results show a similar richness and relative activity of aerial insectivorous bats along the urban ecosystem. The effect of urbanization intensity becomes more apparent in species-specific bat activity; the response of species towards particular habitat conditions depends on local habitat quality and characteristics (i.e., presence of streetlights, vegetation cover and tree density).     

Multivariate log-Birnbaum–Saunders regression models

In this paper, we present a multivariate version of the skewed log-Birnbaum–Saunders regression model. This new family of distributions holds good properties such as marginal variables following univariate skewed log-Birnbaum–Saunders distributions, besides presenting the usual log-Birnbaum–Saunders distribution as a particular case. Furthermore, the model parameters are estimated through maximum-likelihood methods, a closed-form expression for the Fisher’s information matrix is presented, and testing hypothesis for model parameters is performed. Two real datasets are analyzed and results are discussed.     

Transforming the Way We Live Together: A Model to Move Communities From Policy to Implementation

Most cities, counties, and neighborhoods are not designed for an aging population. By providing a range of services to all residents, Lifelong Communities allow individuals to age in place. Although the Lifelong Communities Initiative is based on established guiding principles, little information exists regarding the realities of moving from policy to implementation. The Atlanta Regional Commission conducted a case study in Mableton, Georgia, and found successful implementation requires a combination of support from local citizen groups and government. The Atlanta Regional Commission is replicating these best practices in other communities and providing support to those aspiring to launch or expand Lifelong Communities.