Ancestral Inference in Population Genetics Models with Selection (with Discussion)

A new algorithm is presented for exact simulation from the conditional distribution of the genealogical history of a sample, given the composition of the sample, for population genetics models with general diploid selection. The method applies to the usual diffusion approximation of evolution at a single locus, in a randomly mating population of constant size, for mutation models in which the distribution of the type of a mutant does not depend on the type of the progenitor allele; this includes any model with only two alleles. The new method is applied to ancestral inference for the two‐allele case, both with genic selection and heterozygote advantage and disadvantage, where one of the alleles is assumed to have resulted from a unique mutation event. The paper describes how the method could be used for inference when data are also available at neutral markers linked to the locus under selection. It also informally describes and constructs the non‐neutral Fleming–Viot measure‐valued diffusion.     

Improving OpenURL Menus: User Testing of Revisions to SFX® Menus

Twenty-one volunteers tested the usability of revisions to the Texas A&M University Libraries' SFX® OpenURL link resolver menus, including the addition of Ex Libris' new bX™ recommendation service and a plug-in which pulls additional information about the journal into the menu. The volunteers also evaluated the quality and desirability of the bX recommendations and discussed their preferences for help options and full-text format. Results of the usability testing are reported along with the resultant menu changes. This study will be of interest to librarians implementing or redesigning OpenURL menus as well as those interested in the user experience.     

Q methodology in social work research

This article examines Q methodology as an empirical method for use in social work research. Q methodology applies statistical analysis to the qualitative study of human subjectivity such as attitudes, beliefs, feelings and opinions. Q methodology is effective for obtaining data from small samples, and it offers respondents a concise and valid way of expressing their viewpoints with minimal researcher interference. The article provides an overview of Q methodology and presents an actual example of a small‐scale Q study to facilitate a better understanding of the method. We conclude that Q methodology is especially suitable in social work research with respondents who may have difficulties in expressing themselves when more conventional research methods are used. Q methodology is an efficient tool in research involving the exploration and comparison of different points of view.     

The effects of socioeconomic inequalities of working life on health: implications for an ageing population

Abstract

This study examines suggestions that inequalities in health related to socioeconomic status (SES) will increase in older age. A representative sample of the New Zealand population aged 55–70 years (N = 6662) responded to a postal questionnaire with measures of health (SF-36), SES, and health-related behaviours. Hierarchical multiple regressions supported predictions that the SES of working life will continue to influence physical and mental health in early old age. The strongest predictor was self-reported economic living standards. This subjective measure of SES is an important construct for future investigations of health and wellbeing among older people in an ageing population.     

Poverty and HIV/AIDS in Apartheid South Africa

This article constitutes an attempt to put forward some suggestions towards constructing a framework of understanding the processes of social construction of sexuality and gender identity within the context of the ethnic conflict, and of nationalist/ populist politics in former Yugoslavia. In particular, it focuses on the ways in which masculinist discourse is articulated to the politics of ethnicity in former Yugoslavia, by examining the definition and treatment of women as 'biological reproducers of the nation' through the discourses and policy proposals of moral majority nationalist and pro-life movements in Croatia and Slovenia, and of the nationalist movement and regime in Serbia, and the use of rape and sexual assault against women as 'weapons' in the ethnic conflict in Bosnia and other republics of former Yugoslavia.     

Parametric modelling of prevalent cohort data with uncertainty in the measurement of the initial onset date

In prevalent cohort studies with follow-up, if disease duration is the focus, the date of onset must be obtained retrospectively. For some diseases, such as Alzheimer’s disease, the very notion of a date of onset is unclear, and it can be assumed that the reported date of onset acts only as a proxy for the unknown true date of onset. When adjusting for onset dates reported with error, the features of left-truncation and potential right-censoring of the failure times must be modeled appropriately. Under the assumptions of a classical measurement error model for the onset times and an underlying parametric failure time model, we propose a maximum likelihood estimator for the failure time distribution parameters which requires only the observed backward recurrence times. Costly and time-consuming follow-up may therefore be avoided. We validate the maximum likelihood estimator on simulated datasets under varying parameter combinations and apply the proposed method to the Canadian Study of Health and Aging dataset.