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.     

Group therapists' countertransference reactions to multiple deaths from aids

Group therapists for those with HIV Related Diseases are becoming the “professional” survivors of this world-wide epidemic. From their experiences we may learn a great deal more about the effects of multiple deaths on mental health care professionals. As therapists they are constantly eliciting and listening to the fears, hopes, agonies and terrors of those with this disease. They become the bereaved. Witnesses to the deaths of many of their group members, they struggle with a wide range of emotional responses while at the same time assisting surviving group members in their struggle to live with these deaths. Mourning reactions and countertransference phenomena are in abundance as these therapists grapple with these group processes. This article identifies and examines these therapists' responses by focusing on clinical illustrations drawn from their bi-weekly supervision sessions.     

Developing Age-Friendly Cities: Case Studies From Brussels and Manchester and Implications for Policy and Practice

Developing environments responsive to the aspirations of older people has become a major concern for social and public policy. Policies and programs directed at achieving “age-friendly” communities are considered to require a wide range of interventions, including actions at the level of the social and physical environment. This article compares the age-friendly approaches of two European cities, Brussels and Manchester, with a particular focus on policies and initiatives that promote active aging in an urban context. The article examines, first, the demographic, social, and multicultural contexts of Brussels and Manchester; second, the way in which both cities became members of the World Health Organization Global Network of Age-Friendly Cities and Communities; third, similarities and differences in the age-friendly approaches and actions adopted by both cities; and fourth, opportunities and barriers to the implementation of age-friendly policies. The article concludes by discussing the key elements and resources needed to develop age-friendly cities.     

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.     

Why is the History of Heterosexuality Essential? Beliefs About the History of Sexuality and Their Relationship to Sexual Prejudice

Heterosexual people with more positive attitudes to lesbians and gay men generally believe that homosexuality is immutable, is not a discrete social category, and that homosexuality exists in all cultures and time periods. Equivalent beliefs about heterosexuality and beliefs about components of sexuality have been less often researched. 136 people with diverse sexualities described heterosexuality as more universal across history and culture than homosexuality (Study 1). 69 heterosexual-identified participants similarly believed that love, identity, behavior, and desire were more historically invariant aspects of heterosexuality than of homosexuality (Study 2). Less prejudiced participants thought all components of homosexuality—except for identity—were more historically invariant. Teasing apart beliefs about the history of components of heterosexuality and homosexuality suggests that there is no “essential” relationship between sexual prejudice and the tension between essentialist and constructivist views about the history of sexual identity.