Childhood growth and education migration among ethnic Tibetan children from Nepal.

Background: Ethnographic work among high altitude populations has shown that children are highly mobile-the most recent expression of this is the educational migration of children born at high altitude to boarding schools at lower altitudes. The impact of these patterns of migration on size for age are unknown.

Aim: We investigated the association between growth in weight and height and educational migration in ethnic Tibetan children living in and out of their natal communities.

Repeatability of adaptive traits among ethnic Tibetan highlanders.

Objectives: Connecting traits to biological pathways and genes relies on stable observations. Researchers typically determine traits once, expecting careful study protocols to yield measurements free of noise. This report examines that expectation with test-retest repeatability analyses for traits used regularly in research on adaptation to high-altitude hypoxia, often in settings without climate control.

Trekking and toddlers: Towards a biocultural analysis of growth among infants and young children in a rural region of the Himalayas.

Objectives: Rapid socioeconomic change, associated with development and a growing tourism industry is occurring across the Himalayas. The health impact of this rapid economic development is poorly understood, especially for infants and young children. This study investigated the associations between village level economic differences as indexed by economic development and tourism engagement on infant and young child growth and health in a population of ethnic Tibetans living in the western Himalayas of Nepal.

When women work: Endocrine reactivity in women during everyday physical activity at high altitude.

Objectives: This study explores the acute endocrine reactivity of testosterone and cortisol in women engaging in everyday physical activity in a high altitude environment.

Methods: Data were collected from 35 women living in the Himalayas, with women recruited from both high (>10 000 ft.) and low altitude villages (<10 000 ft.

Detecting past and ongoing natural selection among ethnically Tibetan women at high altitude in Nepal.

Adaptive evolution in humans has rarely been characterized for its whole set of components, i.e. selective pressure, adaptive phenotype, beneficial alleles and realized fitness differential.

Correction: A longitudinal cline characterizes the genetic structure of human populations in the Tibetan plateau.

[This corrects the article DOI: 10.1371/journal.pone.

Ethnically Tibetan women in Nepal with low hemoglobin concentration have better reproductive outcomes.

: Tibetans have distinctively low hemoglobin concentrations at high altitudes compared with visitors and Andean highlanders. This study hypothesized that natural selection favors an unelevated hemoglobin concentration among Tibetans. It considered nonheritable sociocultural factors affecting reproductive success and tested the hypotheses that a higher percent of oxygen saturation of hemoglobin (indicating less stress) or lower hemoglobin concentration (indicating dampened response) associated with higher lifetime reproductive success.

A longitudinal cline characterizes the genetic structure of human populations in the Tibetan plateau.

Indigenous populations of the Tibetan plateau have attracted much attention for their good performance at extreme high altitude. Most genetic studies of Tibetan adaptations have used genetic variation data at the genome scale, while genetic inferences about their demography and population structure are largely based on uniparental markers. To provide genome-wide information on population structure, we analyzed new and published data of 338 individuals from indigenous populations across the plateau in conjunction with worldwide genetic variation data.

Ecological pressures and milk metabolic hormones of ethnic Tibetans living at different altitudes.

Background: Very little is known about how milk hormones, shown to influence growth during infancy, may contribute to patterns of altered growth in high altitude living infants.

Aim: This study investigated the association between maternal BMI, the metabolic hormones adiponectin and leptin in human milk and infant weight for age z-scores (WAZ) in Tibetans.

Subjects And Methods: A sample of 116 mothers and infants (aged 0-36 months) were recruited from two locations: the Nubri Valley, Nepal (rural; altitude = 2400-3900 m) and Kathmandu, Nepal (urban, 1400 m).

Closing the Womb Door: Contraception Use and Fertility Transition Among Culturally Tibetan Women in Highland Nepal.

Objectives Whether in metropoles or remote mountain communities, the availability and adoption of contraceptive technologies prompt serious and wide-ranging biological, social, and political-economic questions. The potential shifts in women's capacities to create spaces between pregnancies or to prevent future pregnancies have profound and often positive biological, demographic, and socioeconomic implications. Less acknowledged, however, are the ambivalences that women experience around contraception use-vacillations between moral frameworks, generational difference, and gendered forms of labor that have implications well beyond the boundaries of an individual's reproductive biology.

Milk at altitude: Human milk macronutrient composition in a high-altitude adapted population of Tibetans.

Objective: The physiological challenges of high altitude have led to population-specific patterns of adaptation. These include alterations to child growth and reproduction, including lactation. However, while breastfeeding has been investigated, nothing is known about milk composition in high altitude adapted populations.

Externally-resident daughters, social capital, and support for the elderly in rural Tibet.

This paper focuses on assistance that externally-resident daughters provide for their aging parents in rural Tibet, China, to challenge the notion that rapid modernization invariably threatens family-based care systems for the elderly. The authors discuss social and economic changes associated with modernization that have created new opportunities for parents to send daughters out of their natal households in ways that can benefit them in old age. By investing in a daughter's education so she can secure salaried employment, or by helping a daughter establish a small business so she can earn an independent livelihood, the authors demonstrate how some externally-resident daughters represent a novel form of social capital that parents can draw on for social support.