Sexual Compulsivity and Sexual Behaviors Among Gay and Bisexual Men and Lesbian and Bisexual Women

Within the existing body of research, the information pertaining to sexual compulsivity (SC) among women, both homo- and heterosexual, remains rather limited in comparison to men. The aim of this study was to assess the prevalence of SC in a community sample of gay and bisexual men and lesbian and bisexual women and to identify differences in sexual practices based on classification as sexually compulsive within gender. Supporting previous research, the findings indicated that gay and bisexual men were significantly higher in SC when compared to lesbian and bisexual women. Similarly, sexually compulsive gay and bisexual men were more likely to report drug use with sex than their non-sexually compulsive peers, suggesting that “party n' play” may play a larger role for men with SC. In addition, the findings demonstrated empirical support for the proposition that lesbian and bisexual women with symptoms of SC were more likely to engage in specialized sexual behaviors in comparison to their non-sexually compulsive peers. These data suggest that SC manifests differently in gay, lesbian, and bisexual men and women.     

Sleep and behavioral correlates of napping among young adults: a survey of first-year university students in Madrid, Spain

Objective: Between November 2002 and March 2003, the authors assessed the prevalence and correlates of napping among Spanish university students. Participants: The sample comprised 1,276 first-year university students; the mean age was 18.74 +/- 1.24 years, and 35.45% were men. Methods: The study was cross-sectional, and the students completed self-report, anonymous questionnaires provided during an in-class survey. Results: Almost half (44%) of the sample reported napping (90% did so after lunch for longer than 1 hour). Multiple logistic regression analysis showed that experiencing an irregular sleep-wakefulness pattern, having a morning school schedule, and being male were significant predictor variables of napping. Further significant outcome variables related to napping were having excessive daytime sleepiness, missing classes because of tiredness, better ability to concentrate later in the afternoon, and a perception of deeper nighttime sleep. Conclusions: Habitual napping is common among Spanish university students and associated with an irregular sleep-wakefulness pattern. Taking long postlunch naps seems to be used by students to cope with insufficient sleep and daytime sleepiness.     

Flexible‐Duration Extended Warranties with Dynamic Reliability Learning

Frequent technological innovations and price declines adversely affect sales of extended warranties (EWs) as product replacement upon failure becomes an increasingly attractive alternative. To increase sales and profitability, we propose offering flexible‐duration EWs. These warranties can appeal to customers who are uncertain about how long they will keep the product as well as to customers who are uncertain about the product's reliability. Flexibility may be added to existing services in the form of monthly billing with month‐by‐month commitments or by making existing warranties easier to cancel with pro‐rated refunds. This paper studies flexible warranties from perspectives of both customers and the provider under customers' reliability learning. We present a model of customers' optimal coverage decisions and show that customers' optimal coverage policy has a threshold structure under some mild conditions. We further show that flexible warranties can result in higher profits and higher attach rates in a homogeneous market as well as in a heterogeneous market with multiple segments differing in various dimensions.     

Properties of Coherent Systems with Dependent Components

We introduce two new families of univariate distributions that we call hyperminimal and hypermaximal distributions. These families have interesting applications in the context of reliability theory in that they contain that of coherent system lifetime distributions. For these families, we obtain distributions, bounds, and moments. We also define the minimal and maximal signatures of a coherent system with exchangeable components which allow us to represent the system distribution as generalized mixtures (i.e., mixtures with possibly negative weights) of series and parallel systems. These results can also be applied to order statistics (k-out-of-n systems). Finally, we give some applications studying coherent systems with different multivariate exponential joint distributions.     

On the q-Weibull Distribution and Its Applications

The q-Weibull distribution is a stretched model for Weibull distribution, obtained by introducing a new pathway parameter q, which facilitates a slow transition to the Weibull as q → 1. In this article, we make a detailed study of the properties of the q-Weibull distribution and we apply it to a data on cancer remission times for which this distribution is a better fit than Weibull. Results relating to reliability properties, estimation of parameters, and applications in stress-strength analysis are also obtained.     

A semi-parametric estimation of a survival function from incomplete and doubly censored data

The purpose of this paper is to present a semi-parametric estimation of a survival function when analyzing incomplete and doubly censored data. Under the assumption that the chance of censoring is not related to the individual's survivorship, we propose a consistent estimation of survival. The derived estimator treats the uncensored observations nonparametrically and uses parametric models for both right and left censored data. Some asymptotic properties and simulation studies are also presented in order to analyze the behavior of the proposed estimator.     

Modified Tukey's Control Chart

Phase I of control analysis requires large amount of data to fit a distribution and estimate the corresponding parameters of the process under study. However, when only individual observations are available, and no a priori knowledge exists, the presence of outliers can bias the analysis. A relatively recent and successful approach to address this situation is Tukey's Control Chart (TCC), a charting method that applies the Box Plot technique to estimate the control limits. This procedure has proven to be effective for symmetric distributions. However, when skewness is present the average run length performance diminishes significantly. This article proposes a modified version of TCC to consider skewness with minimum assumptions on the underlying distribution of observations. Using theoretical results and Monte Carlo simulation, the modified TCC is tested over several distributions proving a better representation of skewed populations, even in cases when only a limited number of observations are available.     

A work in progress: the metabolic syndrome

Metabolic syndrome refers to a constellation of risk factors for cardiovascular disease. They include elevated plasma glucose concentrations, dyslipidemia, hypertension, and abdominal obesity. These conditions typically occur during middle age or later in life. Although there is no clear consensus on the diagnosis of metabolic syndrome, it is a potentially important entity to recognize and manage once traditional cardiovascular risk factors, such as smoking, hypertension, dyslipidemia, and diabetes, have been treated individually. This Perspective summarizes our current knowledge of the metabolic syndrome. Lifestyle change, including diet and exercise, is probably the best available option for treating the metabolic syndrome. However, rigorous lifestyle interventions are difficult to implement outside of a clinical trial setting, especially among elderly patients.     

Meaning-Making,Negotiation, and Change in School Accountability,Or What Sociology Can Offer Policy Studies

In school systems around the world, countless reform strategies have focused on school and teacher accountability—the process of evaluating schools’ performance on the basis of student measures. Policy and education research has been dominated by debates on its effectiveness, where advocates highlight the positive effects on achievement while critics emphasize the negative consequences on pressure, morale, and autonomy. Yet the question is not so much whether to have accountability, but what form it should take. To answer this, sociologists contribute through their study of accountability’s organizational and ecological dynamics—key facets that are sidelined when researchers only focus on quantitative program evaluation. An organizational perspective highlights the meaning-making school actors and the general public have of the policy, viewing it through technical-rationalist and institutional-performative lenses. An ecological perspective highlights how the form of accountability is a negotiated outcome of larger macrosocial forces, and how accountability is itself contributive to larger social changes. This review suggests a broader conceptualization of accountability regimes, and the unique contribution of critical, organizational, and sociological perspectives to the study of public policies.