Powerful nonparametric statistics to compare k independent ROC curves

The authors deal with the problem of comparing receiver operating characteristic (ROC) curves from independent samples. From a nonparametric approach, they propose and study three different statistics. Their asymptotic distributions are obtained and a resample plan is considered. In order to study the statistical power of the introduced statistics, a simulation study is carried out. The (observed) results suggest that, for the considered models, the new statistics are more powerful than the usually employed ones (the Venkatraman test and the usual area under the ROC curve criterion) in non-uniform dominance situations and quite good otherwise.     

Inducing efficient conditional cooperation patterns in public goods games, an experimental investigation

This study analyses the behavior in a repeated public goods game when subjects know about the possibility of existence of strict conditional cooperators. We employed a baseline treatment and a threat treatment in which subjects are informed about the possibility of being in a group together with automata playing a grim trigger strategy. We conjecture the resulting game allows for almost fully efficient outcomes. Contributions in the threat treatment increase by 40% before a surprise restart, and by 50% after the surprise restart. In line with the grim trigger strategy subjects contribute either all or nothing in the threat treatment.     

Spatial Analysis of the Relationship Between a Life Quality Index,HDI and Poverty in the Province of Buenos Aires and the Autonomous City of Buenos Aires,Argentina

The study of Quality of Life, Poverty and Human Development shares several elements. Nonetheless, while poverty is a measure of “lack” based on a set of basic need variables (unsatisfied basic needs—UBN), human development index (HDI) is derived from the notion of human capabilities. Quality of Life, however, is a measure of achievement. Our goal is to analyze the degree of spatial correspondence between a life quality index (LQI) and the other indices by using bivariate spatial autocorrelation with its global and local values. The comparison of these three indicators at a municipal level in the province of Buenos Aires and in the Autonomous City of Buenos Aires (the Federal Capital of Argentina) reveals a medium spatial correspondence which leaves room for discussion about the scope and limitations of the indicators. HDI and UBN have a similar spatial configuration while the LQI yields a more fragmented distribution associated to the complexity of its variables, dimension and weights.     

Caffeine intake is not associated with serum testosterone levels in adult men: cross-sectional findings from the NHANES 1999–2004 and 2011–2012

Objective: The association of caffeine intake with testosterone remains unclear. We evaluated the association of caffeine intake with serum testosterone among American men and determined whether this association varied by race/ethnicity and measurements of adiposity.

Methods: Data were analyzed for 2581 men (≥20?years old) who participated in the cycles of the NHANES 1999–2004 and 2011–2012, a cross-sectional study. Testosterone (ng/mL) was measured by immunoassay among men who participated in the morning examination session. We analyzed 24-h dietary recall data to estimate caffeine intake (mg/day). Multivariable weighted linear regression models were conducted.

Results: We identified no linear relationship between caffeine intake and testosterone levels in the total population, but there was a non-linear association (p_nonlinearity?p_nonlinearity?≤?.03 both) and only among men with waist circumference <102?cm and body mass index <25?kg/m² (p_nonlinearity?Conclusion: No linear association was identified between levels of caffeine intake and testosterone in US men, but we observed a non-linear association, including among racial/ethnic groups and measurements of adiposity in this cross-sectional study. These associations are warranted to be investigated in larger prospective studies.     

Building stronger weak ties among a diverse pool of emergent nonprofit leaders of color

This article explores theoretical underpinnings of social capital and strong and weak ties as they relate to relationships within, between, and among six cohorts of promising nonprofit leaders of color in a northwestern U.S. city. Using mixed methods, including network analyses, it considers the impact and potential of a university‐community collaboration to deliver a program to promising emergent leaders nominated for their talent and commitment to the work of their community‐based organizations, often in competition for limited resources. The article considers the program's implicit effect on relationships and reveals intersector connections among alumni. Findings show substantial alumni movement among organizations, increasing the potential for collaboration and mentoring relationships. We conclude with recommendations for programs seeking long‐term impact and discuss a series of unanticipated findings and the questions they engender, many critical as communities and organizations become more diverse and social needs do not diminish.     

Cities and the state in Spain

Conclusions Leaving aside details and qualifications, the major turning point in relations between cities and the monarchy occurred during the second half of the sixteenth century. The cities paid a very high price for their initial support of the crown. The more the logic of imperial power took over, the less cities had any chance of developing on their own. Nonetheless, they never became simple toys in royal hands. At the beginning of the seventeenth century, as the power of Genoan financiers declined, the monarchy tried again to obtain the support of cities, which finally gave in - at a price. The most crucial price of all was the imposition on the crown of a fiscal system (the servicios de millones) that was even more favorable than the alcabala to the cities having votes in the Cortes. Furthermore, the millones placed severe restrictions on the monarch's use of the funds; from that point on, the monarch had to avert his eyes from the procedures the privileged cities used to collect the taxes that constituted his principal ordinary revenues.Unlike the French case, the Spanish experience, as seen from Castile, did not end with the complete submission of cities to the monarchy's expansive centralization. Yet we must recognize that the cities never tried to create a form of political organization that could have been a Castilian version of the urban republics. Formally the situation unfolded as a series of ritual confrontations in the Cortes, where each of the parties was well aware of its limits. With that balance of forces, any attempt to enhance state power the monarchy tried to initiate could only succeed with the approval of the cities.This series of intermediate barriers meant that the process by which communities became subject to statist royal power was halting and indirect. In addition, great administrative decisions became diluted when they entered the interlocked network formed by local urban authorities. Not until the first half of the eighteenth century, after the liquidation of Spain's imperial territories elsewhere in Europe, can we speak of the consolidation of an administrative monarchy, a true predecessor of what one day would become a Spanish state.     

Ergonomics evaluation of a government office building

An ergonomics team from the US Army Center for Health Promotion and Preventive medicine evaluated 465 video display terminal (VDT) workstations in a Government office building over an 18-day period. Each workstation evaluation involved an assessment of the worker, the chair, the desk, the keyboard, the pointing device, the monitor, and the office environmental conditions. The team also collected worker pain and injury information. The problems seen during the evaluation were characteristic of most office environments where VDT workstation furniture was purchased before the advent of mouse-driven software. The majority of furniture evaluated was not designed to meet the demands of intensive mouse use for prolonged periods of time. Much of the workstation furniture was not adjustable, chairs lacked adequate back support, and workers assumed non-neutral postures. As a result, more than 35% of the workers evaluated complained of on-the-job pain. New office furniture that is adjustable, adequate desk space and storage space were among the solutions recommended by the ergonomics team.     

Global patterns of healthy life expectancy for older women

This paper focuses on patterns of healthy life expectancy for older women around the globe in the year 2000, and on the determinants of differences in disease and injury for older ages. Our study uses data from the World Health Organization for women and men in 191 countries. These data include a summary measure of population health, healthy life expectancy (HALE), which measures the number of years of life expected to be lived in good health, and a complementary measure of the loss of health (disability-adjusted life years or DALYs) due to a comprehensive set of disease and injury causes. We examine two topics in detail: (1) cross-national patterns of female-male differences in healthy life expectancy at age 60; and (2) identification of the major injury and disability causes of disability in women at older ages. Globally, the male-female gap is lower for HALE than for total life expectancy. The sex gap is highest for Russia (10.0 years) and lowest in North Africa and the Middle East, where males and females have similar levels of healthy life expectancy, and in some cases, females have lower levels of healthy life expectancy. We discuss the implications of the findings for international health policy.     

Challenges and Strategies for Conducting Program-Based Research in After-School Settings

Findings from children and youth who participated in structured after-school interventions in four urban public housing communities are used to illustrate the complexities of conducting program-based research in after-school settings. Findings from four field investigations reveal the importance of family support, reading skills, parent involvement, and positive peers in engaging youth in services, developing academic skills and avoiding involvement in problem behavior. Challenges in conducting program-based research and lessons learned from each of the four studies are discussed in the context of social work practice and after-school programming for at-risk children and youth.