On the distribution of completed parities when fertility is heritable

"Over the last one hundred years, there has been, in many developed countries, a demographic convergence towards the two child family. The possible implications for population growth of such a tendency are considered in this paper in terms of both family limitation and also the intergenerational transmission of fertility. These two effects interact so that as the proportion of two-child families increases, the possible influence of mother-daughter fertility associations on population growth decreases, though even now it could override otherwise significant changes in either or both of the birth and death intensities. In particular, it is shown that according...to how fertility is transmitted through generations, it is still possible to have zero growth rates consistently with a widely dispersed stable distribution of family size as well as a typical mortality regime." (SUMMARY IN FRE)     

Population growth with variable family size

"The Sharpe-Lotka continuous time deterministic model of population growth is developed to take account of some possible forms of mother-daughter fertility association....Model specific results relating the intergenerational fertility effect to the long term population growth rate and magnitude are established. The quantitative implications of the theory are illustrated by a consideration of a general bilinear form of A and in this context numerical results illustrating the finite time growth and also the long term distribution of fertility levels in the stable female population are obtained. In particular, it is shown that different fertility specific subpopulations can coexist indefinitely."     

Population growth with variable family size

The Sharpe‐Lotka continuous time deterministic model of population growth is developed to take account of some possible forms of mother‐daughter fertility association, characterised here by a bivariable measure, A. This leads to a linear double integral equation for which, subject to certain conditions, a finite time solution can be found by Laplace transform methods and thus also model specific results relating the intergenerational fertility effect to the long term population growth rate and magnitude are established. The quantitative implications of the theory are illustrated by a consideration of a general bilinear form of A and in this context numerical results illustrating the finite time growth and also the long term distribution of fertility levels in the stable female population are obtained. In particular, it is shown that different fertility specific subpopulations can coexist indefinitely.     

The quality of mother‐adolescent disclosure: Links with predictors and adolescents’ sociomoral outcomes

Previous work on adolescents’ disclosure has focused on the frequency of disclosure to parents, but not the quality of that disclosure. Therefore, there is a need to examine factors that predict the quality of adolescents’ disclosure, as well as the consequences of the quality for adolescents’ outcomes. In this study, 100 adolescents (M age = 14.27 years; 57 girls; 70.7% White, European American) disclosed to mothers a recent past event in which they felt excluded; the videotaped and transcribed conversations were rated for indices of the quality of disclosure (i.e., the quality of elaboration and emotion discussed). Adolescents completed measures of sociomoral behavior and parental warmth and mothers completed measures of their moral identity, circle of moral regard, and moral socialization. The quality of adolescents’ disclosure was related to adolescents’ sociomoral outcomes (including prosocial behaviors, empathy, and sociability). Adolescents’ disclosure quality was predicted by gender and by aspects of mothers’ moral sophistication. Findings highlight the importance of high‐quality self‐disclosure by adolescents for promoting adolescents’ moral development, potentially because such disclosure gives parents the opportunity to help adolescents cope with challenging peer experiences potentially through emotion coaching and problem‐solving. Moreover, the findings are novel because they highlight how maternal moral processes might promote adolescents’ disclosure.     

A winner determination problem of tendering transportation services

Summary  For the tendering of long-term transportation contracts in the bulk industry, shippers use bidbooks that specify for each lane the load location, the destination, the product and the volume that has to be transported over the next so many years. Bidbooks are sent out to a preselected group of carriers, who subsequently quote a price for each of the lanes. After the return of the bidbooks, the shipper determines the winning carriers. The winner determination problem is the problem of finding an allocation of the lanes to the carriers so as to minimize total transportation costs. The winner determination problem is NP-hard in the strong sense. We model the winner determination problem as an integer linear programming (ILP) problem and try and solve the model by use of CPLEX, a state-of-the-art ILP solver. It turns out, that the model can solve problems optimally with no more than 270 lanes. We also develop a fast randomized heuristic, and we show that it performs remarkably well, with a gap of no more than 0.8% from optimality.

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Zusammenfassung  Zum Abschluss langfristiger Transportvertr?ge in der Massengüterindustrie bedienen sich die Spediteure bestimmter Angebotsbücher, in denen für jede Tour die Ladestation, der Zielort, sowie die zu transportierende Produktart und deren Volumen für die n?chsten Jahre spezifiziert werden. Die Angebotsbücher werden an eine ausgew?hlte Gruppe von Transportunternehmen geschickt, die dann für jede Tour einen Preis angeben. Auf dieser Grundlage bestimmt der Spediteur dann die Transportunternehmen, die die Zuteilung der Touren erhalten. Dabei wird die Verteilung der Touren auf die Transportunternehmen in der Weise vorgenommen, dass die gesamten Transportkosten minimiert werden. Das Auswahlproblem ist NP-hard in strengem Sinne. Wir modellieren das Auswahlproblem als ganzzahliges lineares Programmierungsproblem (ILP) und testen bzw. l?sen es mit Hilfe mit CPLEX, einem Standardl?sungsansatz für ganzzahlige lineare Programmierung. Dabei zeigt sich, dass Modelle bis zu 270 Touren optimal gel?st werden k?nnen. Zugleich wird auch eine Heuristik entwickelt und vorgestellt, deren L?sung nur unwesentlich von der Optimall?sung entfernt liegt.

     

Does corporal punishment erode the quality of the mother–child interaction in early childhood?

Corporal punishment is believed to exert its influence partially on children's externalizing behavior by undermining the quality of parent‐child relationships, but empirical evidence for this belief is lacking. Thus, the goal of this study was to explore longitudinally whether the use of corporal punishment by mothers was associated with declining quality in parent‐child interactions and whether these declines mediated the links between corporal punishment and later externalizing behavior. Based on data from the NIHCD SECCYD, the findings from this study indicated that the links between the quality of parent‐child interaction and corporal punishment were bidirectional: high quality parent‐child interaction was associated with less use of subsequent corporal punishment by mothers, and maternal use of corporal punishment at 36 months was associated with declines in the quality of parent‐child interaction at 54 months. There were not significant indirect effects of corporal punishment at 36 months on grade 3 aggression through 54 month parent‐child interaction quality, however, which suggests other mechanisms might account for the links between early corporal punishment and later externalizing problems.     

Risk assessment of sex offenders: the current position in the UK

This paper examines the various risk factors that are considered in the current risk assessments used with sex offenders, and the strengths and weaknesses of each. In addition, particular attention is given to the assessments that are currently employed within the prison and probation services. Static instruments, dynamic instruments and combined approaches are evaluated, as are clinical assessments of risk. In particular, the now commonly used joint Prison‐Probation Offender Assessment System risk prediction instrument (OASys) is considered, with an evaluation of the relevance of the factors included in making an assessment of risk and whether this is supported by research into recidivism amongst sex offenders. Copyright © 2006 John Wiley & Sons, Ltd.