Effects of testosterone administration on liver structure and function in aging rats

Aging males have a decrease in testosterone levels, by which the testosterone treatment may influence in a negatively fashion the liver.

Aim: This study aimed to analyze the effects of aging with or without testosterone administration on the liver components of animals.

Methods: Wistar rats were divided into three groups: 20 months’ group (G20), 24 months’ group (G24), group treated with testosterone for 16 weeks (GT). All groups were sacrificed at 24 months except for G20 that was sacrificed at 20 months.

Results: Aging and testosterone treatment alters the body weight (BW), liver weight (LW) and relative liver weight. Besides, testosterone increased the mitogen capacity of hepatocytes. Nonetheless, we reinforce the negative effects of testosterone on old animals’ liver as chronic hepatic congestion and/or cholestasis. In addition, we observed that testosterone plays an important role on hepatic glycogen stores.

Conclusions: Our study showed many implications for the knowledge about the effects of aging with or without testosterone administration on old animals’ liver.     

Tackling Poverty-migration Linkages: Evidence from Ghana and Egypt

Are migrants able to use the migration experience to their benefit, that is to improve their livelihoods, and is this result nuanced by whether migrants are poor or non-poor? This paper explores these questions quantitatively using data on migrants and non-migrants from Ghana and Egypt. It describes the main challenges in the empirical literature and introduces a conceptual model to explore the links between migration and poverty. The empirical model accounts for the direct effects of migration on poverty and for the role of migration in moderating the dynamics of poverty. Results show the selectivity of migration with respect to subjective poverty and that migration can have a significant impact on helping people improve their livelihoods. The paper further finds that selectivity with respect to human capital depends on ‘reasons for migration’ and visa status. These findings enrich existing empirical studies by providing a clear estimation of sequential events and enable policymakers to better understand the processes behind migration and poverty.     

Comparison of Bayesian models for production efficiency

In this paper, we use Markov Chain Monte Carlo (MCMC) methods in order to estimate and compare stochastic production frontier models from a Bayesian perspective. We consider a number of competing models in terms of different production functions and the distribution of the asymmetric error term. All MCMC simulations are done using the package JAGS (Just Another Gibbs Sampler), a clone of the classic BUGS package which works closely with the R package where all the statistical computations and graphics are done.     

Macroeconomic Determinants of Equilibrium Unemployment Insurance

This paper proposes a new modeling strategy as regards the definition of an optimal level of unemployment benefits. While the traditional methodology privileges labor market equilibrium to derive optimal employment, wage and unemployment benefit levels, we present a model in which the optimal level of unemployment benefits is a function of the government’s macroeconomic objectives in terms of inflation and output fluctuations. In a second stage, the model allows for the investigation of unemployment insurance effects on labor market equilibrium.     

Development and Validation of a Self-Reported Measure of Job Performance

Social Indicators Research - The current turbulent context in which we live in requires, more and more, that organisations focus on improving the workers’ performance. Individual performance...     

Defective models induced by gamma frailty term for survival data with cured fraction

In this paper, we propose a defective model induced by a frailty term for modeling the proportion of cured. Unlike most of the cure rate models, defective models have advantage of modeling the cure rate without adding any extra parameter in model. The introduction of an unobserved heterogeneity among individuals has bring advantages for the estimated model. The influence of unobserved covariates is incorporated using a proportional hazard model. The frailty term assumed to follow a gamma distribution is introduced on the hazard rate to control the unobservable heterogeneity of the patients. We assume that the baseline distribution follows a Gompertz and inverse Gaussian defective distributions. Thus we propose and discuss two defective distributions: the defective gamma-Gompertz and gamma-inverse Gaussian regression models. Simulation studies are performed to verify the asymptotic properties of the maximum likelihood estimator. Lastly, in order to illustrate the proposed model, we present three applications in real data sets, in which one of them we are using for the first time, related to a study about breast cancer in the A.C.Camargo Cancer Center, São Paulo, Brazil.     

Discrete and continuous bivariate lifetime models in presence of cure rate: a comparative study under Bayesian approach

The modeling and analysis of lifetime data in which the main endpoints are the times when an event of interest occurs is of great interest in medical studies. In these studies, it is common that two or more lifetimes associated with the same unit such as the times to deterioration levels or the times to reaction to a treatment in pairs of organs like lungs, kidneys, eyes or ears. In medical applications, it is also possible that a cure rate is present and needed to be modeled with lifetime data with long-term survivors. This paper presented a comparative study under a Bayesian approach among some existing continuous and discrete bivariate distributions such as the bivariate exponential distributions and the bivariate geometric distributions in presence of cure rate, censored data and covariates. In presence of lifetimes related to cured patients, it is assumed standard mixture cure rate models in the data analysis. The posterior summaries of interest are obtained using Markov Chain Monte Carlo methods. To illustrate the proposed methodology two real medical data sets are considered.     

Aiming to keep poor Mexican families at the breadline (but no higher): The effects of minimum wage,tax, and social policy changes between 1994 and 2012

Welfare policy in Mexico has been transformed in recent decades. During the years of the import‐substitution industrialization economic strategy and the hegemonic party political regime, social policy was based on social insurance programs of limited coverage to urban formal sector workers and their families. In the mid‐1990s, an unprecedented expansion of social protection through social assistance programs was triggered, along with social insurance reform. This article assesses the effects at the household level of social policy changes, in combination with changes in taxes and the minimum wage, which also impact the welfare of the population. The research applies “model families” to establish effects of social, tax, and minimum wage policy changes across population groups, and their combined potential to combat poverty. Findings show that although taxation and social policy changes increased redistribution towards poor families, their capacity to lift and keep them above poverty thresholds was limited by the drop in the real value of the minimum wage and by strict targeting mechanisms, which exclude families that do not meet eligibility criteria but still fall below poverty lines. Social policy expansion merely subsidized the drop in real minimum wage, and poor families at best remained at similar income levels. Hence, the logic of the design of welfare policy changes can be characterized as aiming to keep poor families on the breadline, but no higher.     

The Ripple Effect: Lessons Learned About Secondary Traumatic Stress Among Clinicians Responding to the September 11th Terrorist Attacks

Secondary Traumatic Stress (STS) symptoms experienced by mental health clinicians who treated clients for issues related to the terrorist attacks of 9/11 were intense and unprecedented. An exploratory study, using qualitative techniques as the primary information gathering method, was conducted to gain a better understanding about “indirect” exposure to terrorism. Twenty-six mental health clinicians participated in this research effort. As part of this study, questions regarding STS were explored. STS levels among clinicians who provided care to victims of 9/11 were high 30?months after the attacks. Most clinicians lacked experience providing disaster relief mental health care. Availability of supervision and agency support was described as “weak;” however, peer support was deemed helpful. Over the past decade, progress has been made in addressing STS issues. Implications are included for social work practice, disaster mental health administration, funding sources and policy. Recommendations for future research are identified.