Biomechanical analysis of older adults stepping up: a method of evaluating balance

The aim of this study was to analyze differences in biomechanical parameters between elderly and control participants when stepping up, to evaluate control of balance. Eleven control and 14 elderly participants performed a step from an initial static posture onto a 7-cm-high force plate. For the spontaneous-velocity condition, elderly participants performed a slower progression velocity than control participants. Elderly participants spent proportionally more time in stance phase, with a corresponding decrease in swing phase, than the control participants, irrespective of movement velocity. In contrast, at spontaneous velocity the parameters related to ground-reaction force (GRF) showed that anteroposterior and mediolateral forces at toe-off of the support limb and the slope of vertical force during weight transfer were significantly smaller for the elderly than for control participants. These GRF parameters depended on the stepping-up velocity. The elderly develop a spatiotemporal strategy and reduced movement velocity to control support balance.     

Intergenerational reliance on social assistance: Evidence from Canada

This paper provides the first analysis of the intergenerational transmission of participation in a Canadian social assistance program. Two sources of intergenerational transmission are taken into account: one that is due to a possible causal link between parents' and children's participation, and one that is due to a correlation between individual and environment specific characteristics across generations. The basic data come from the Québec government's administrative records and cover 17,203 young people who were 18 years old in 1990 and whose parents were recipients of social assistance during at least one month between 1979 and 1990. The results reveal that, on average, a one-percentage unit increase in parental participation during the youth's pre-adult years (age 7–17) raises the youth's participation rate by 0.29 percentage unit during early adulthood (age 18–21). This impact is stronger during the early stages of childhood (age 7–9) and during late adolescence (age 16–17).     

Early Theory of Mind Competencies: Do Infants Understand Others’ Beliefs?

Recent studies suggest that even infants attend to others’ beliefs in order to make sense of their behavior. To warrant the assumption of early belief understanding, corresponding competences need to be demonstrated in a variety of different belief‐inducing situations. The present study provides corresponding evidence, using a completely nonverbal object‐transfer task based on the general violation‐of‐expectation paradigm. A total of n = 36 infants (15‐month‐olds) participated in one of three conditions. Infants saw an actor who either observed an object’s location change, did not observe it, or performed the location change manually without seeing it (i.e., variations in the actor’s information access). Results are in accordance with the assumption that 15‐month‐old infants master different belief‐inducing situations in a highly flexible way, accepting visual as well as manual information access as a proper basis for belief induction.     

Body Image Development and Sexual Satisfaction: A Prospective Study From Adolescence to Adulthood

The aim of the current study was to explore whether developmental trajectories of body satisfaction from adolescence to young adulthood predicted measures of sexual satisfaction in young adulthood, even when controlling for important covariates such as gender, weight development, relationship status, mental health, and frequency of sexual intercourse and masturbation. Data were collected from a population-based prospective cohort of Norwegian adolescents (n = 2,587) over a period of 13 years in four waves (1992, 1994, 1999, and 2005; mean age = 14.9 in 1992, 57.3% women). Latent growth curves were estimated for body satisfaction and body mass index (BMI). Men reported higher sexual satisfaction, sexual activity, baseline body satisfaction, and BMI than women. The developmental trajectories revealed a slight increase in body satisfaction and BMI from adolescence to young adulthood in both genders. Moreover, structural equation models showed that baseline body satisfaction in both genders predicted sexual satisfaction as a young adult, independent of relationship status and frequency of sexual activity. Neither the development of BMI nor of body satisfaction predicted sexual satisfaction. The results elucidate the vital role of body satisfaction in sexual satisfaction in adults and the importance of addressing body dissatisfaction in childhood.     

Detecting level shifts in ARMA-GARCH (1,1) Models

The purpose of this article is to present a new method to detect level shifts in the context of conditional heteroscedastic models. First, we define precisely what type of outlier we are referring to, a concept that has been scarcely touched in the field of GARCH (1,1) models, and then we go on to present our methodology based on the nature of the Lagrange multiplier tests. The validity and efficiency of the proposed procedure are demonstrated through different simulation experiments. To conclude, we present a practical application of the method to the time series of returns of US short-term interest rates.     

Constrained egalitarianism in a simple redistributive model

The paper extends a result in Dutta and Ray's (1989) theory of constrained egalitarianism initiated by relying on the concept of proportionate rather than absolute equality. We apply this framework to redistributive systems in which what the individuals get depends on what they receive or pay qua members of generally overlapping groups. We solve the constrained equalization problem for this class of models. The paper ends up comparing our solution with the alternative solution based on the Shapley value, which has been recommended in some distributive applications.