The COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) project is a large international collaborative effort to analyze individual-level phenotype data from twins in multiple cohorts from different environments. The main objective is to study factors that modify genetic and environmental variation of height, body mass index (BMI, kg/m2) and size at birth, and additionally to address other research questions such as long-term consequences of birth size. The project started in 2013 and is open to all twin projects in the world having height and weight measures on twins with information on zygosity. Thus far, 54 twin projects from 24 countries have provided individual-level data. The CODATwins database includes 489,981 twin individuals (228,635 complete twin pairs). Since many twin cohorts have collected longitudinal data, there is a total of 1,049,785 height and weight observations. For many cohorts, we also have information on birth weight and length, own smoking behavior and own or parental education. We found that the heritability estimates of height and BMI systematically changed from infancy to old age. Remarkably, only minor differences in the heritability estimates were found across cultural–geographic regions, measurement time and birth cohort for height and BMI. In addition to genetic epidemiological studies, we looked at associations of height and BMI with education, birth weight and smoking status. Within-family analyses examined differences within same-sex and opposite-sex dizygotic twins in birth size and later development. The CODATwins project demonstrates the feasibility and value of international collaboration to address gene-by-exposure interactions that require large sample sizes and address the effects of different exposures across time, geographical regions and socioeconomic status.

The National Academy of Sciences-National Research Council (NAS-NRC) Twin Registry is one of the oldest, national population-based twin registries in the USA. It comprises 15,924 White male twin pairs born in the years 1917–1927 (N = 31.848), both of whom served in the armed forces, chiefly during World War II. This article updates activities in this registry since the most recent report in Twin Research and Human Genetics (Page, 2006). Records-based data include information from enlistment charts and Veterans Administration data linkages. There have been three major epidemiologic questionnaires and an education and earnings survey. Separate data collection efforts with the NAS-NRC registry include the National Heart, Lung, and Blood Institute (NHLBI) subsample, the Duke Twins Study of Memory in Aging and a clinically based study of Parkinson’s disease. Progress has been made on consolidating the various data holdings of the NAS-NRC Twin Registry. Data that had been available through the National Academy of Sciences are now freely available through National Archive of Computerized Data on Aging (NACDA).

Common law was an all-male system, with one glaring exception: juries of matrons. If a convicted felon requested a reprieve from execution on the grounds of pregnancy, it was the responsibility of a group of twelve matrons to perform an inspection in order to determine if she was in fact pregnant. Matrons were in a position of great authority. Their verdicts were definitive: if they decided a woman was pregnant, then she was sent back to prison. Despite the significance of their role, little is known about medieval matrons and what qualified them to sit on a jury. Were they mothers? Honorable wives? Midwives? The goal of this paper is to argue that matrons had training in obstetrics. This was particularly important for medieval matrons because the quickening (that is ensoulment, signaled by the first fetal movements) did not become the focal point of the matrons' assessment until at least 1348. Before this, the diagnosis was much more medically challenging as matrons had to determine whether a felon had conceived. Overall, the medieval records demonstrate great confidence in medieval matrons and their obstetrical expertise.

Better health requires sectors like housing and education, and healthcare, to collaborate. That needs three strategies. Make full use of waivers to foster experimentation. Use techniques to encourage agencies at all levels to work together. And use new incentives to foster local partnerships.