Les relations intergénérationnelles et quelques modèles qui en découlent

Lotka's model of population consists of a dynamic process of population renewal which connects fertility, survival and age-structure with each other. It requires the assumption of stability of demographic parameters. We suggest here a static approach, which relates different cohorts to each other by chains (links, bonds) of decent and ascent, and which does not require any assumptions about demographic stability.     

A prospective study of the onset of sexual behavior and sexual risk in youth perinatally infected with HIV

Perinatally HIV-infected (PHIV+) youth are surviving into adolescence and young adulthood. Understanding the sexual development of PHIV+ youth is vital to providing them with developmentally appropriate HIV-prevention programs. Using pooled data (N = 417) from two longitudinal studies focused on HIV among youth (51% female; 39% HIV+) and their caregivers (92% female; 46% HIV+), the rate of sexual onset during adolescence across four youth-caregiver combinations was compared: PHIV+ youth with HIV+caregivers (12%), PHIV+ youth with HIV- caregivers (27%), HIV- youth with HIV+caregivers (34%), and HIV- youth with HIV- caregivers (27%). Youth with HIV- caregivers were more likely than other youth-caregiver groups to have had their sexual onset. Youth with HIV+ caregivers reported a slower rate of onset of penetrative sex across the adolescent years. Findings are discussed by highlighting the role that both youth and caregiver HIV status play in the onset of sexual behavior across adolescence.     

Aging and well-being in French older adults regularly practicing physical activity: a self-determination perspective

The purpose of this study was to identify the motivational profiles of physically active older adults and to achieve a better understanding of their perceived motives to explain their regular physical activity behavior in relation to self-determination theory (SDT). To address these aims, this study used quantitative and qualitative approaches. Older adults (n = 92; M = 74.95, SD = 4.6) completed the French version of the Sport Motivational Scale. A cluster analysis showed two motivational profiles with differential motivational patterns. The first was named the high combined profile, with high scores on intrinsic motivation and introjected regulation and low levels of external regulation. The second profile was the low to moderate motivational profile, with low scores on intrinsic motivation and moderate scores on introjected regulation. The qualitative study's results demonstrate the usefulness of SDT in explaining the relationship between these motivational profiles and the intertwining of the three basic psychological needs.     

Polynomial structures in rank statistics distributions

This paper deals with the classical problem of how to evaluate the joint rank statistics distributions for two independent i.i.d. samples from a common continuous distribution. It is pointed that these distributions rely on an underlying polynomial structure of negative binomial type. That property is exploited to obtain, in a systematic and unified way, closed forms and simple recursions, some well established, for computing the joint tail and rectangular probabilities of interest.     

A goodness-of-fit test for overdispersed binomial (or multinomial) models

Overdispersion or extra variation is a common phenomenon that occurs when binomial (multinomial) data exhibit larger variances than that permitted by the binomial (multinomial) model. This arises when the data are clustered or when the assumption of independence is violated. Goodness-of-fit (GOF) tests available in the overdispersion literature have focused on testing for the presence of overdispersion in the data and hence they are not applicable for choosing between the several competing overdispersion models. In this paper, we consider a GOF test proposed by Neerchal and Morel [1998. Large cluster results for two parametric multinomial extra variation models. J. Amer. Statist. Assoc. 93(443), 1078–1087], and study its distributional properties and performance characteristics. This statistic is a direct analogue of the usual Pearson chi-squared statistic, but is also applicable when the clusters are not necessarily of the same size. As this test statistic is for testing model adequacy against the alternative that the model is not adequate, it is applicable in testing two competing overdispersion models.     

Community Literacy Resources and Home Literacy Practices Among Immigrant Latino Families

ABSTRACT

This paper reports relationships among communities, families, and Spanish-speaking children's language and literacy development in kindergarten and grade 1. Findings from a study of 35 communities show that communities with greater concentrations of Latinos are less likely to have printed materials, and available materials are more likely to be in Spanish. Communities with higher income and education levels have more literacy materials in English. Contrary to predictions, there are few associations among community literacy resources, frequency of children's home reading activities, and children's literacy achievement. This lack of association is due to within-community variation in home literacy practices and to schools' impact on home literacy. However, there are associations among community and family language characteristics and child literacy outcomes in Spanish and English, suggesting that at least in the early stages of literacy development, communities' influence on Spanish-speaking children's literacy development is through language-learning opportunities rather than literacy-learning opportunities per se.     

A Shorter and Multidimensional Version of the Gambling Attitudes and Beliefs Survey (GABS-23)

The Gambling Attitudes and Beliefs Survey (GABS) is a questionnaire which explores gambling-related dysfunctional beliefs in an unidimensional way. The present research aims to investigate the dimensionality of the scale. 343 undergraduate student gamblers and 75 pathological gamblers seeking treatment completed the GABS and the south oaks gambling screen. Exploratory and confirmatory factor analyses revealed that the original one-factor structure of the GABS did not fit the data effectively. We then proposed a shorter version of the GABS (GABS-23) with a new five-factor structure, which fitted with the data more efficiently. The comparisons between students (problem vs. non-problem gamblers) and pathological gamblers seeking treatment indicated that the GABS-23 can discriminate between problem and non-problem gamblers as efficiently as the original GABS. To ensure the validity and the stability of the new structure of the GABS-23, analyses were replicated in an independent sample that consisted of 628 gamblers (256 non problem gamblers, 169 problem gamblers who are not treatment-seeking and 203 problem gamblers seeking treatment). Analyses showed satisfactory results, and the multidimensional structure of the GABS-23 was then confirmed. The GABS-23 seems to be a valid and useful assessment tool for screening gambling-related beliefs, emotions and attitudes among problem and non-problem gamblers. Moreover, it presents the advantage of being shorter than the original GABS, and of screening irrational beliefs and attitudes about gambling in a multidimensional way. The five-factor model of the GABS-23 is discussed based on the theory of locus of control.