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.     

Stress and musculoskeletal discomfort among hydrocarbon industry workers in Mexico

This study of 114 workers in the hydrocarbon industry was conducted to identify the relationship between stress and musculoskeletal discomfort, and to view the roles played by such factors as age, schooling, obesity, workplace and job seniority. All factors except seniority were found to affect the presence of musculoskeletal discomfort in some area of the body.     

The Effect of Solution‐Focused Versus Problem‐Focused Questions: A Replication

In therapeutic conversations, questions can be considered as interventions in their own right. This study is a cross‐cultural replication of Grant (Journal of Systemic Therapies, 2012, 31, 2, 21) study on the effects of different types of questions on various clinically relevant variables. A total of 204 students of a Spanish university described a real‐life problem that they wanted to solve and were then randomly assigned to either a solution‐focused or a problem‐focused questions condition. Before and after answering the questions, they completed a set of measures that assessed positive and negative affect, self‐efficacy, and goal attainment. Solution‐focused questions produced a significantly greater increase in self‐efficacy, goal approach, and action steps than problem‐focused questions, and a significantly greater decrease in negative affect, providing further empirical support to solution‐focused practices.     

A team level investigation of the relationship between Leader–Member Exchange (LMX) differentiation,and commitment and performance

Although the differential treatment of team members by their leader is at the heart of Leader–Member Exchange (LMX) theory, empirical studies exploring the role of within-team LMX differentiation in relation to team outcomes are still relatively scarce. This study among 269 Dutch secondary school teachers from 33 different teams tested the hypotheses that the relationship between LMX differentiation and team commitment, and team performance is moderated by LMX-quality median. Moreover, we hypothesized that team members' perceived dissimilarity regarding work values and orientations would be positively related to within-team LMX differentiation. Teachers completed questionnaires on LMX-quality, dissimilarity, and team commitment, whereas team performance was rated by school principals. Results indeed showed that LMX differentiation is positively related to both outcome variables in teams with a low LMX-quality median only. As expected, more perceived dissimilarity between team members was related to more within-team variability in LMX-scores. These results contribute to knowledge on hypothetical antecedents and consequences of LMX differentiation at the team level.     

Activity patterns and temporal niche partitioning of dogs and medium-sized wild mammals in urban parks of Xalapa,Mexico

Urban Ecosystems - Free-ranging domestic dogs are the world most common exotic carnivore species that could negatively interact with the native wildlife as predators, competitors, and disease...     

From industrial restructuring to the financial crisis: Mainstream nationalism and minimum income in the Basque Country

The uneven development of minimum incomes in Spain is one of the factors that explain the significant differences in the poverty indicators that characterize the Spanish regions, generally in favour of the territories most committed to these policies (Basque Country, Navarra and Asturias). However, there are other aspects that deserve some consideration when interpreting the specific method of developing minimum incomes in southern Europe. One aspect has to do with the differing dynamics of countries, such as Spain and Italy, which have opted for a decentralized regional model. In this regard, the regional autonomous initiative of the Basque Country played a decisive role in promoting minimum income programs in the late 1980s. Without its leadership in the launch of the regional minimum income policy, Spanish trade unions would probably not have opted for this method as a mechanism for combating poverty in the 1990s. No Italian region went on to play this driving role at that time. This article analyses the ideological foundations of the Basque minimum income policy introduced in the late 1980s and which grew significantly before and during the crisis that started in 2007-2008. It examines the dominant political narrative on this issue by analysing the discourse of some of the key nationalist leaders involved in the birth and development of the minimum income scheme. The approach shows that the experience of social decline linked to industrial restructuring processes was instrumental in the construction of the nationalist narrative.     

Is Over-Education a Problem in Spain? Empirical Evidence Based on the EU-SILC

Spain is suffering an important economic slowdown which affects significantly to unemployment rises. For this reason, many individuals are considering to increase their educational level. However, this decision can lead to get worse labor market indicators. In this paper, we analyze the problem of over-education in Spain and its effect on earnings. Using the last four waves (2009–2012) of the European Union Statistics on Income and Living Conditions (EU-SILC, 2009–2012) this study analyses over-education situation of employed people and compares over-education rates and earnings of these individuals. Cross-sectional analysis (focused on a recent period of time) is performed. We apply different matching techniques based on propensity score methods to evaluate the impact of over-education on personal earnings. The results obtained in this paper add more empirical evidence supporting the effect of education on earnings together with occupational placement because over-education could be a great problem for many countries. In Spain, there exists a problem of over-education which varies among occupations. Overeducated workers are most likely to be found among “Service workers and shop and market sales workers” and “Elementary occupations”. Also, the majority of individuals working as “Professionals” are adequately educated. Besides, over-education has a significant negative impact on earnings. Although the results depend on the way we define over-education (interval or modal method), those individuals over-educated receive less earnings than they correspond to. In fact, the decrease can reach about 5000 euro per year.     

Campylobacter QMRA: A Bayesian Estimation of Prevalence and Concentration in Retail Foods Under Clustering and Heavy Censoring

A Bayesian statistical temporal‐prevalence‐concentration model (TPCM) was built to assess the prevalence and concentration of pathogenic campylobacter species in batches of fresh chicken and turkey meat at retail. The data set was collected from Finnish grocery stores in all the seasons of the year. Observations at low concentration levels are often censored due to the limit of determination of the microbiological methods. This model utilized the potential of Bayesian methods to borrow strength from related samples in order to perform under heavy censoring. In this extreme case the majority of the observed batch‐specific concentrations was below the limit of determination. The hierarchical structure was included in the model in order to take into account the within‐batch and between‐batch variability, which may have a significant impact on the sample outcome depending on the sampling plan. Temporal changes in the prevalence of campylobacter were modeled using a Markovian time series. The proposed model is adaptable for other pathogens if the same type of data set is available. The computation of the model was performed using OpenBUGS software.     

Efficiency Analysis of the European Food Banks: Some Managerial Results

Hundreds of thousands of people in Europe are daily receiving food, thanks to local food banks, run basically by volunteers who collect donations and distribute them to organizations. In this paper, data from a sample of food banks working in 13 European countries are analysed using Data Envelopment Analysis (DEA), trying to learn about their profiles and find some clues about the efficiency of their operations, comparing them according to variables such as the number of volunteers and permanent staff, the tonnage of food delivered and the number of people served. Significant inefficiencies were found in the sector as a result of high performance of some food banks, thus setting a high level standard of operational efficiency. Some additional results regarding food bank sizes and performance are presented.