An alternative competing risk model to the Weibull distribution for modelling aging in lifetime data analysis

A simple competing risk distribution as a possible alternative to the Weibull distribution in lifetime analysis is proposed. This distribution corresponds to the minimum between exponential and Weibull distributions. Our motivation is to take account of both accidental and aging failures in lifetime data analysis. First, the main characteristics of this distribution are presented. Then, the estimation of its parameters are considered through maximum likelihood and Bayesian inference. In particular, the existence of a unique consistent root of the likelihood equations is proved. Decision tests to choose between an exponential, Weibull and this competing risk distribution are presented. And this alternative model is compared to the Weibull model from numerical experiments on both real and simulated data sets, especially in an industrial context.     

Differential Reliance on the Duchenne Marker During Smile Evaluations and Person Judgments

When evaluating the smiles of other people (regarding amusement, authenticity, spontaneity, or intensity), perceivers typically rely on Orbicularis oculi activity that causes wrinkles around a target’s eyes. But does this so-called Duchenne marker also impact more generalized judgments of person characteristics (e.g., regarding a target’s attractiveness, intelligence, dominance, and trustworthiness)? To address this issue, the current study asked participants to provide the above smile evaluations and person judgments for a series of Duchenne and non-Duchenne smiles. The results showed that smile evaluations uniformly increased during Duchenne marker presence. The marker’s effect on person judgments, in contrast, was judgment dependent. While attractiveness, dominance and intelligence ratings showed the expected enhancement, trustworthiness ratings remained unaffected by the facial cue of interest. The findings suggest that the Duchenne marker’s role as a cue of social relevance during target perception depends on the type of person inference under consideration.     

Experiences with the French aging males' symptoms (AMS) scale

Introduction.?The aim of this paper is to report on experiences gained from the application of the French version of the Aging Males' Symptoms (AMS) scale, to show correlations with other relevant scales and to provide population reference values for France.

Methods.?A representative survey based on an existing, representative population panel was performed in France (963 males, aged 15 + years). Other AMS data from Europe were then used for comparison. Mean scores of the French AMS scale do not systematically differ from the data of other European studies. The population reference values obtained for France strongly suggest that the scale measures can appreciate the level of well-being whatever the patients' age; however, some variables, such as age and family income, can influence the total AMS scores. Comparisons with the generic quality-of-life scale, SF-12, and a depression scale, HAD, have shown good correlations, as have comparisons with the ADAM questionnaire.

Conclusion.?The French AMS scale is a standardized, valid and simple health-related quality of life (HRQoL) scale, with results comparable to other published European findings. The results also indicate that the AMS scale can be used to measure and compare HRQoL in those less than 40 years of age.     

Effects of sleep inertia on cognitive performance following a 1-hour nap

Abstract

This study investigated the effects of a 1-h nap on subsequent performance in spatial memory (SM) and logical reasoning (LR) tasks. The objective was to evaluate the duration of the effects of sleep inertia (SI). The performance was measured in two independent groups of subjects. The 1-h nap took place at 00:00 h in group 1 and at 03:00 h in group 2. In each task, the experimental design comprised one no-nap condition in which subjects had no sleep before the night tests, and a nap condition that comprised the 1-h nap followed by the test sessions. To measure the duration of SI effects, the subjects were tested in two 30-min sessions and the data in each session were analysed in sub-units of time of 3 min each. In each task the results showed no effects on accuracy, and no circadian effects of napping were found. In each task, analyses of pooled data of the two groups showed that the performance in the 1-h nap condition exhibited significant reductions of speed immediately following awakening, when compared with no-nap, reflecting SI effects. In SM, the slowing lasted 24 min, and 27 min in LR. Practical implications of the results are discussed.     

Risk and choice: A research saga

The economic theory of decision making under risk has seen remarkable advances over the 50 years since Pratt’s (1964) characterization of risk aversion under expected utility. We review developments in three key areas to which Louis Eeckhoudt has made significant contributions: (1) increases in risk and risk taking; (2) self-protection and risk aversion; and (3) higher (and lower) order derivatives of utility. For each, we identify seminal papers, puzzles, and recent developments. The saga of research on these topics reveals that important contributions were made long ago and yet significant gains in understanding continue to be made. Recent advances often have roots in early results and researchers can profit by examining the old as well as the new papers.     

Observer,consigner, tracer. Les usages d’un cahier électronique controversé en établissement pénitentiaire pour mineurs

This contribution, based on research conducted within a Prison for Minors, provides an analysis of the guards’ use of a software application: the “electronic observation logbook”, designed to record and disseminate various day-to-day “observations” about prisoners. The analysis of the use of this system — which simultaneously attempts to “profile” prisoners and “track” surveillance activity — not only helps conceptually identify the type of surveillance employed in a Prison for Minors, it also reveals the growing complexity of the work of prison guards, previously studied primarily in terms of the informality of the interactional frameworks in prison.