Breaking the rules: sex roles and genetic mating system of the pheasant coucal.

Generally in birds, the classic sex roles of male competition and female choice result in females providing most offspring care while males face uncertain parentage. In less than 5% of species, however, reversed courtship sex roles lead to predominantly male care and low extra-pair paternity. These role-reversed species usually have reversed sexual size dimorphism and polyandry, confirming that sexual selection acts most strongly on the sex with the smaller parental investment and accordingly higher potential reproductive rate.

A personal history: social medicine in a South African setting, 1952-5. Part 2: Social medicine as a calling: ups, downs, and politics in Alexandra Township.

This is the second and concluding part of a personal history of social medicine in South Africa in the early years after the second world war.

A personal history: social medicine in a South African setting, 1952-5. Part 1: The shape of ideas forged in the second world war.

The second part of this personal history focusing on the ups, downs, and politics of social medicine in Alexandra Township, South Africa, will be published in the August issue of the journal.

Preventing mother-to-child HIV transmission in the new millennium: the challenge of breast feeding.

Short courses of antiretroviral drugs have greatly enhanced the prospect of reducing mother-to-child HIV transmission. Yet transmission by breast feeding clouds hopes for this seemingly simple intervention. We revisit mathematical models to assess the competing risks associated with feeding by breast vs.

Origins and early development of the case-control study: Part 2, The case-control study from Lane-Claypon to 1950.

The first modern case-control study was Janet Lane-Claypon's study of breast cancer in 1926, but the design was used only sporadically in medicine and the social sciences until 1950, when four published case-control studies linked smoking and lung cancer. These 1950 studies synthesized the essential elements of the case-control comparison, produced a conceptual shift within epidemiology, and laid the foundation for the rapid development of the case-control design in the subsequent half century.

Origins and early development of the case-control study: Part 1, Early evolution.

This paper traces the origins and early development of the case-control study, focusing on its evolution in the 19th and early 20th century. As with other forms of clinical investigation, the case-control study emerged from practices that originally belonged to the realm of patient care. This form of disease investigation can be viewed as the knitting together of medical concepts (caseness, disease etiology, and a focus on the individual)--and medical procedures (anamnesis, grouping of cases into series; and comparisons of the diseased and the healthy)--that are of ancient origin, but which were seldom brought together until the 20th century.

Risk of cranial ultrasound abnormalities in very-low-birth-weight infants conceived with assisted reproductive techniques.

Objective: To evaluate risks of cranial ultrasound abnormalities among very-low-birth-weight (VLBW) infants conceived with fertility therapy (ovulation induction only or with assisted reproductive techniques [ART]) and of multiple gestation pregnancies.

Study Design: The incidences of cranial ultrasound abnormalities in 1473 VLBW infants conceived with and without fertility therapy and born of multiple versus singleton pregnancies were compared, using logistic regression models.

Results: Infants conceived with ART were less likely to have intraventricular hemorrhage (IVH).

Cocaine use during pregnancy and intrauterine growth retardation: new insights based on maternal hair tests.

Prenatal cocaine use is more accurately measured by maternal hair assay than by urine toxicology screening or self-report. To investigate the consequences of improved measurement, the authors ascertained cocaine use during pregnancy by maternal hair test, urine test, and self-report in a sample of 691 patients recruited from one New York City hospital in 1990-1992. Associations with intrauterine growth retardation, head circumference, and length of gestation were investigated.

Do clinical markers of barotrauma and oxygen toxicity explain interhospital variation in rates of chronic lung disease? The Neonatology Committee for the Developmental Network.

Objective: To explore the hypothesis that variation in respiratory management among newborn intensive care units (NICUs) explains differences in chronic lung disease (CLD) rates.

Design: Case-cohort study.

Setting: NICUs at 1 medical center in New York (Babies' and Children's Hospital [Babies']) and 2 in Boston (Beth Israel Hospital and Brigham and Women's Hospital [Boston]).