Triangle plots of three-level explanatory variables

Thalassaemias are genetic blood disorders which cause varying degrees of anaemia. Their geographical distribution suggests a compensating protection against malaria, which kills between 0.5 and 2.5 million people per year in developing countries. Neal Alexander describes a study in Papua New Guinea which estimated this association more directly, and a triangle plot which clarified, for himself and his non-statistician colleagues, the relative risks of malaria for those with none, one or two copies of the relevant haemoglobin mutation.     

Split Hamiltonian Monte Carlo

We show how the Hamiltonian Monte Carlo algorithm can sometimes be speeded up by “splitting” the Hamiltonian in a way that allows much of the movement around the state space to be done at low computational cost. One context where this is possible is when the log density of the distribution of interest (the potential energy function) can be written as the log of a Gaussian density, which is a quadratic function, plus a slowly-varying function. Hamiltonian dynamics for quadratic energy functions can be analytically solved. With the splitting technique, only the slowly-varying part of the energy needs to be handled numerically, and this can be done with a larger stepsize (and hence fewer steps) than would be necessary with a direct simulation of the dynamics. Another context where splitting helps is when the most important terms of the potential energy function and its gradient can be evaluated quickly, with only a slowly-varying part requiring costly computations. With splitting, the quick portion can be handled with a small stepsize, while the costly portion uses a larger stepsize. We show that both of these splitting approaches can reduce the computational cost of sampling from the posterior distribution for a logistic regression model, using either a Gaussian approximation centered on the posterior mode, or a Hamiltonian split into a term that depends on only a small number of critical cases, and another term that involves the larger number of cases whose influence on the posterior distribution is small.     

The Untold Story of 50 Years of Adolescent Fertility in West Africa: A Cohort Perspective on the Quantum,Timing, and Spacing of Adolescent Childbearing

Although recent studies examine overall fertility trends in West Africa, few using advanced demographic techniques focus on adolescents. This study explores long‐term patterns of adolescent childbearing in 12 West African countries using 51 Demographic and Health Surveys covering birth cohorts that span 54 years (1940–1994). We employ classic demographic measures as well as disaggregation by early‐ (10–14 years old), middle‐ (15–17), and late adolescence (18–19). Cohort‐based estimates of total adolescent births, parity progression ratios, and rapid repeat birth probabilities reveal little change over time. Most women begin childbearing in adolescence, the progression to additional adolescent births remains common, and the incidence of rapid repeat births is high. In recent cohorts, women exit adolescence with an average of between 0.4 (Ghana) to 1.3 (Niger) births. Contrary to common assumptions, it is women commencing motherhood in early‐ and middle‐, not later adolescence, who account for most West African adolescent fertility.     

Statement of Withdrawal: Statistical analysis of an endemic disease from a capture–recapture experiment

There are a number of statistical techniques for analysing epidemic outbreaks. However, many diseases are endemic within populations and the analysis of such diseases are complicated by changing population demography. Motivated by the spread of cowpox among rodent populations, a combined mathematical model for population and disease dynamics is introduced. An MCMC algorithm is then constructed to make statistical inference for the model based on data being obtained from a capture–recapture experiment. The statistical analysis is used to identify the key elements in the spread of the cowpox virus.     

Consensus in the Marital Dyad: Couples' Perceptions of Contraception,Communication, and Family Life

Abstract

The present study was based on data collected (separately for husbands and wives) from 365 couples to determine levels of consensus on a series of variables related to the family forming process. Following Scheff (1967), consensus was operationalized as both agreement and coorientation in the marital dyad. The data generally indicated low levels of consensus on such variables as contraceptive efficacy, desired family size, child spacing, unwanted pregnancies, communication with spouse, and levels of alienation. The results are discussed within the framework of family planning and effective fertility control.     

Community standards,conservatism, and judgments of pornography

In an attempt to determine if a community standard existed and to relate judgments of pornography to conservatism, scores on Wilson and Patterson's Conservatism Scale, yes‐no judgments on whether 25 pictures were or were not pornographic, and demographic data were obtained from a random sample (N = 114) of a community. Results were as follows: (1) suggestive evidence for the existence of a community standard; (2) the c‐scale correlated .57 (N = 114, p < .01) with number of pictures judged pornographic; (3) the 25 pictures met Guttman requirements of unidimensionality (reproducibility of .925); and (4) factor analysis of the pornography judgments yielded three clear‐cut factors and one ambiguous factor which were ordered along the Guttman dimension.     

Aging male bodies,health and the reproduction of age relations

This article explores the ways in which a group of male factory workers uses bodies as bases for hierarchical categorization of men by age in their talk of mundane aspects of their lives. Analysis of interviews about health (4 focus groups and 5 personal interviews) with Finnish working-class men under 40 years old shows that they portray age groups to which they do not belong as careless, even irresponsible toward health and its maintenance. As they categorize youth and old people by age, they leave themselves unmarked by it, providing no vocabulary to describe their own group. Despite their tendency to distance themselves particularly from old people, they also distinguish among older men by familiarity, providing relatively nuanced accounts of their fathers' aging. We discuss the marking of age groups in terms of social inequality and talk of fathers in terms of intergenerational relations. Even family ties among men of diverse ages involve ageism, which familiarity serves both to mitigate and to make less visible. This article documents the maintenance of age inequality in everyday, mundane behavior.     

An ethical code for AOD faculty: a proposed set of guidelines

Ethical codes of conduct are accepted requirements for membership in state and national organizations that grant credentials to those who are employed as alcohol and other drug (AOD) counselors, prevention specialists, and clinical supervisors. It seems appropriate to explore the possibility of an ethical code directly linked to addiction faculty which will outline their unique educational responsibilities and standards. The authors suggest development and adoption of such an ethical code for college-level addiction studies faculty and this proposal is offered as a move toward that possibility.     

Engaging Indigenous Communities: Towards a Policy Framework for Indigenous Community Justice Programmes

Community engagement has come to the fore as a policy and programme approach that seeks to connect citizens both with each other and with government in order to deliver improved social and economic opportunities and outcomes. This model has become a key aspect of the intervention approach within Indigenous communities and is seen to have particular application in addressing community justice issues. This article examines a suite of community justice initiatives being used in Indigenous communities in Australia with a view to ascertaining how the principles of community engagement are operationalized. The article draws on this information and argues that community engagement is only one aspect of a number of community‐oriented justice initiatives currently being applied. These initiatives range from concepts of community as a location, community as an interest group, and the leveraging of community capital so as to tap into and build better and stronger relationships. In so doing, the latter attempts to increase the social infrastructure, resources and capacity of communities. However, despite government attention in this area, there is a lack of a policy and programmatic framework to guide a coherent and apposite approach to issues of community in specific policy settings. The article contributes to the development of a framework that begins the process of differentiating and assessing justice administration interventions.