Usefulness and Reliability of Tanner Pubertal Self‐Rating to Urban Black Adolescents in South Africa

Self‐rating of pubertal development is the recommended method to assess puberty in large community‐based surveys of adolescent development and behavior. The aim of this study was to validate for the first time pubertal self‐assessment using the sexual maturation scale developed by Tanner among Black South African adolescents (n=182) aged between 10 and 18 years who were recruited and assessed at public schools in Soweto—Johannesburg. There was significant concordance between adolescents' and same sex health professional's assessment of pubic hair growth and breast development in females (κ coefficients .71 and .76, respectively; p<.0005), and pubic hair growth and genital development in males (κ coefficients .63 and .60, respectively; p<.0005). We conclude that the Tanner pubertal self‐rating appears to be a reasonably valid instrument to use among black South African youth. The tool can be administered in school or other community‐based settings with moderate confidence provided the procedure is thoroughly explained to the participant through the developed tutorial in the language of choice, and privacy and confidentiality are assured.     

Career story: Actuarial researcher

In school, Shane Whelan loved science and had ambitions to become a physicist. But, although he has fulfilled his ambition of doing research, it is in actuarial science rather than physics. He tells Helen Joyce how the switch happened.     

Conflicting motives in evaluations of sequences

Prior research involving choices among sequences differing in trend has typically documented a preference for improving sequences. However, when we investigated sequence preferences using allocation and pricing tasks we found no evidence for a preference for improving sequences. We propose that different measurement procedures highlight or suppress varied considerations that drive preferences toward present consumption, future consumption or temporal neutrality. We discuss our results in the broader context of constructed preferences and convergent validity.     

A new approach to assessing ethical conduct in scientific work

The intent of the current article is to describe the development of a new approach to the study of ethical conduct in scientific research settings. The approach presented in this article has two main components. The first component entails the development of a taxonomy of ethical events as they occur across a broad range of scientific disciplines. The second involves the identification of proximate criteria that will allow systematic and objective evaluation of ethical behaviors through low-fidelity performance simulations. Two proposed measures based on the new approach are intended to identify and measure variations in the scientific environment that might predispose certain individuals to make unethical decisions.     

The Environmental Geochemistry and Bioaccessibility of Mercury in Soils and Sediments: A Review

There have been many studies of mercury geochemistry in the environment and its bioconcentration/bioaccumulation through the aquatic food chain. However, there is a dearth of information regarding the bioaccessibility of mercury in human receptors exposed primarily by soil ingestion. This paper reviews the current state of knowledge of mercury bioaccessibility and speciation in soils, and the utility of speciation methods to estimate mercury bioaccessibility. We conclude that additional research is necessary to determine: (1) whether analytical measurements can adequately determine the bioaccessibility of mercury in sediments and soils; (2) the accuracy of in vitro analyses in assessing mercury bioaccessibility; (3) the ability of mercury to cross tissue membranes of the mouth, esophagus, stomach, and the small and large intestines; (4) the speciation and distribution of mercury in biological fluids; and (5) mercury bioavailability using an in vivo animal model relevant to human gastrointestinal tract conditions.     

Measuring Intergenerational Time Preference: Are Future Lives Valued Less?

Prior research has estimated intergenerational time preferences by asking respondents to choose between hypothetical life saving programs. From such choices, researchers have concluded that the public heavily discounts the lives of people in future generations. However, using a multiversion survey involving 401 respondents, I show that imputed intergenerational time preferences can be dramatically affected by the specific question that is asked. Different elicitation procedures can yield widely varying results by evoking or suppressing various relevant considerations (such as uncertainty). Many formats revealed no preference for current generations over future generations.