Effect of testosterone therapy on lumbar spine and hip mineral density in elderly men

Objective.?The aim of the present study was to analyse the effect of testosterone therapy on bone mineral density in healthy elderly men who had low levels of total testosterone.

Design.?Randomized, double-blind, placebo-controlled study.

Participants.?Forty-eight men over 60 years old with decreased testosterone levels (≤320 ng/dL) comprised the study. Twenty-five out of 48 received intramuscular injections of testosterone enanthate every three weeks during 12 months; the remaining 23 participants formed the control group. All participants had measurements of bone mineral density (BMD) in both lumbar spine and hip before and at the end of the study as well as testosterone and 17-β estradiol levels.

Results:?Testosterone treated group exhibited a significant (p < 0.05) increment (from 1.198 ± 0.153 to 1.240 ± 0.141 g/cm²) in lumbar BMD in parallel with a significant (p < 0.001) increment (from 301 ± 32 to 471 ± 107 ng/dL) in testosterone concentrations, whereas no significant change occurred in femoral neck BMD.

Conclusions.?Testosterone therapy elicited a positive effect only in lumbar BMD in elderly men with diminished testosterone serum levels.     

Transnational Discursive Opportunities and Social Movement Risk Frames Opposing GMOs

Research on social movement frames has been cumulative. Recently, scholars started studying the structural incentives and constraints for claim-makers by relying on the concept of discursive opportunity structure (DOS) while bringing the public sphere and the media to the centre of analysis of political contention. This article draws on these literatures to investigate social movement campaigns against genetically modified (GM) crops and pesticides in Argentina, Brazil and Mexico. First, it argues that there is a transnational DOS that provides structural incentives and constraints to frame risks in symbolic struggles to define GM crops. Next, based on a content analysis of national newspapers, it describes the use of risk frames in national public discourses. Finally, it addresses the question of how this transnationalized DOS is framed by the media by looking at the discursive opportunities for social movements as well as other collective actors in their framing disputes. The study provides evidence of a transnationalization of public debates and offers explanations for national variations by resorting to other components of the DOS such as national policy discourse, timing of political agendas, media structure and culture. It concludes by recognizing the need to consider the various dimensions of opportunity structures for movement action, i.e. political, discursive, and economic, and their relative degree of transnationalization or autonomy over global forces.     

Young Muslim women of Bengali and Moroccan origin in Italy: multiple belongings,transnational trajectories and the emergence of European Islam

This paper investigates the multiple dimensions in the identity constructions of the daughters of the Muslim migrations to Italy. It focuses on the transformations in the way girls and young women relate to religion, in the transition from the generation of mothers, who emigrated from countries with a Muslim majority, to the generation of daughters, who grow up in a European context where Islam is a minority religion. It discusses ‘transmissions’, ‘translations’ and ‘betrayals’ in the migration experience, from a standpoint which highlights the specificities of gender and of generation. The article is based on an intersectional analysis of biographical accounts by Muslim girls and young women of Bengali and Moroccan origin who were born and/or grew up in Italy. Intersecting religious identity with other identity lines such as national belonging (to the parents’ country of origin and to the country where they were born or grew up), gender, class, color and age, multiple reactions and positions emerged. In this context, the religious dimension inherited/experienced/reinvented/called into question by the daughters of migrations appeared to be in constant evolution. Indeed, the stories contained herein of young Muslims tell of the emergence of European Islam.     

The Population Education Transition Curve: Education Gradients Across Population Exposure to New Health Risks

The salutary effect of formal education on health-risk behaviors and mortality is extensively documented: ceteris paribus, greater educational attainment leads to healthier lives and longevity. Even though the epidemiological evidence has strongly indicated formal education as a leading “social vaccine,” there is intermittent reporting of counter-education gradients for health-risk behavior and associated outcomes for certain populations during specific periods. How can education have both beneficial and harmful effects on health, and under which contexts do particular effects emerge? It is useful to conceptualize the influence of education as a process sensitive to the nature, timing of entry, and uniqueness of a new pleasurable and desirable lifestyle and/or product (such as smoking) with initially unclear health risks for populations. Developed herein is a hypothesis that the education gradient comprises multiple potent pathways (material, psychological, cognitive) by which health-risk behaviors are influenced, and that there can be circumstances under which pathways act in opposite directions or are differentially suppressed and enhanced. We propose the population education transition (PET) curve as a unifying functional form to predict shifting education gradients across the onset and course of a population’s exposure to new health risks and their associated consequences. Then, we estimate PET curves for cases with prior epidemiological evidence of heterogeneous education gradients with health-risk behaviors related to mass-produced cigarettes in China and the United States; saturated fats, sugar, and processed food diets in Latin America; and HIV infection in sub-Saharan Africa. Each offers speculation on interactions between environmental factors during population exposure and education pathways to health-risk behaviors that could be responsible for the temporal dynamics of PET curves. Past epidemiological studies reporting either negative or positive education gradients may not represent contradictory findings as much as come from analyses unintentionally limited to just one part of the PET process. Last, the PET curve formulation offers richer nuances about educational pathways, macro-historical population dynamics, and the fundamental cause of disease paradigm.     

Influence of chronic exercise on serum cortisol levels in older adults

The circulating level of cortisol is regulated by the hypothalamic-pituitary-adrenal axis through a neuroendocrine feedback circuit. This circuit can be activated by physiological stimuli such as stress, diseases, and exercise. High levels of serum cortisol hormone normally occur as a byproduct of aging, and can cause several types of damage to the organism and exacerbate immunosenescence. There is a great deal of variability in the cortisol response with regard to type, intensity, volume, and frequency of exercise. However, these relationships have been extensively studied with respect to the acute effects of exercise. Despite the well-known effects of acute exercise on cortisol response, it is unclear how it is affected by chronic exercise and the aging process. Therefore, the aim of this study was to conduct a review of studies that attempt to analyze the influence of chronic exercise on serum cortisol hormone in older people. In order to accomplish this goal, a review from 1970 to June 2012 period was performed using the following databases: Biological Abstracts, PsycINFO, PubMed/Medline, and the Web of Science. Eight articles met the criteria used in this study. Based on the included articles, chronic exercise may influence the serum levels of cortisol levels in older people. Despite this evidence, these results may not be generalized to the entire population of older people, given the few number of studies and especially because the studies showed diversity in variables and methodologies.     

The unit extended Weibull families of distributions and its applications

In this paper, two new general families of distributions supported on the unit interval are introduced. The proposed families include several known models as special cases and define at least twenty (each one) new special models. Since the list of well-being indicators may include several double bounded random variables, the applicability for modeling those is the major practical motivation for introducing the distributions on those families. We propose a parametrization of the new families in terms of the median and develop a shiny application to provide interactive density shape illustrations for some special cases. Various properties of the introduced families are studied. Some special models in the new families are discussed. In particular, the complementary unit Weibull distribution is studied in some detail. The method of maximum likelihood for estimating the model parameters is discussed. An extensive Monte Carlo experiment is conducted to evaluate the performances of these estimators in finite samples. Applications to the literacy rate in Brazilian and Colombian municipalities illustrate the usefulness of the two new families for modeling well-being indicators.     

Cure rate survival models with missing covariates: a simulation study

In this paper we study the cure rate survival model involving a competitive risk structure with missing categorical covariates. A parametric distribution that can be written as a sequence of one-dimensional conditional distributions is specified for the missing covariates. We consider the missing data at random situation so that the missing covariates may depend only on the observed ones. Parameter estimates are obtained by using the EM algorithm via the method of weights. Extensive simulation studies are conducted and reported to compare estimates efficiency with and without missing data. As expected, the estimation approach taking into consideration the missing covariates presents much better efficiency in terms of mean square errors than the complete case situation. Effects of increasing cured fraction and censored observations are also reported. We demonstrate the proposed methodology with two real data sets. One involved the length of time to obtain a BS degree in Statistics, and another about the time to breast cancer recurrence.     

Cigarette smoking, friendship factors, and social norm perceptions among central and Eastern European high school students

Studies investigating smoking behavior among adolescents living in post-communistic Central-European countries are sparse. This study focused on the relationship between cigarette smoking, certain friendship factors, and social norm perceptions among 1,886 Central-Eastern European adolescents from high schools in Hungary, Slovakia, Czech Republic, and Romania. Smoking behavior was related to having friends who smoke, ease or difficulty making new friends, time spent with friends after school and during evenings, and estimations of the prevalence of smoking by schoolmates. Because these youth appear to overestimate the prevalence of smoking by schoolmates, the use of a norms-correction strategy may have potential merit in smoking prevention efforts targeting these adolescents. Smoking prevention and reduction are critical issues for Central-Eastern European youth because they appear to smoke cigarettes at a high rate.