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Objectives: This study of Samburu pastoralists (Kenya) employs a same‐sex sibling design to test the hypothesis that exposure in utero to severe drought and maternal psychosocial stress negatively influence children's growth and adiposity. As a comparison, we also hypothesized that regional climate contrasts would influence children's growth and adiposity based on ecogeographical patterning. Materials and Methods: Anthropometric measurements were taken on Samburu children ages 1.8–9.6 years exposed to severe drought in utero and younger same‐sex siblings (drought‐exposed, n = 104; unexposed, n = 109) in two regions (highland, n = 128; lowland, n = 85). Mothers were interviewed to assess lifetime and pregnancy‐timed stress. Results: Drought exposure associated to lower weight‐for‐age and higher adiposity. Drought did not associate to tibial growth on its own but the interaction between drought and region negatively associated to tibial growth in girls. In addition, drought exposure and historically low rainfall associated to tibial growth in sensitivity models. A hotter climate positively associated to adiposity and tibial growth. Culturally specific stressors (being forced to work too hard, being denied food by male kin) associated to stature and tibial growth for age. Significant covariates for child outcomes included lifetime reported trauma, wife status, and livestock. Discussion: Children exposed in utero to severe drought, a hotter climate, and psychosocial stress exhibited growth differences in our study. Our results demonstrate that climate change may deepen adverse health outcomes in populations already psychosocially and nutritionally stressed. Our results also highlight the value of ethnography to identifying meaningful stressors. [ABSTRACT FROM AUTHOR]

The work effort of prehistoric males relative to females has long been of interest to anthropologists, particularly in foraging versus farming groups. This knowledge requires a clear understanding of the sexual division of labor, or the dichotomy in subsistence roles allocated to males and females. Such research in the Prehispanic American Southwest has been limited. As previous work has shown that bone is the osseous template that reflects in vivo activity levels, it is possible to assess gender-based differences in past work effort using analyses of geometric properties of bone and calculations of bilateral asymmetry. Our research comparatively analyzed upper limb work effort by sex and subsistence in two skeletal samples from disparate economic groups, foragers and farmers, both from similar desert environments. The residentially mobile foragers are from the Lower Pecos region of southwest Texas and the farmers are from the aggregated pueblo of Pottery Mound in south central New Mexico. Humeri from 27 adult foragers (n = 11 males; n = 17 females) and 65 adult farmers (n = 38 males; n = 27 females) were selected for study. All humeri were radiographed and/or scanned and digitized. Statistical comparisons using two-way ANOVAs indicate that female farmers exhibited the greatest humeral strength and the least asymmetry. Relative to all other groups examined, female farmers engaged in higher levels of upper limb work effort implying a substantial economic contribution to their agricultural economy. [ABSTRACT FROM AUTHOR]

Given the well-documented fact that human body proportions covary with climate (presumably due to the action of selection), one would expect that the Ipiutak and Tigara Inuit samples from Point Hope, Alaska, would be characterized by an extremely cold-adapted body shape. Comparison of the Point Hope Inuit samples to a large (n > 900) sample of European and European-derived, African and African-derived, and Native American skeletons (including Koniag Inult from Kodiak Island, Alaska) confirms that the Point Hope Inuit evince a cold-adapted body form, but analyses also reveal some unexpected results. For example, one might suspect that the Point Hope samples would show a more cold-adapted body form than the Koniag, given their more extreme environment, but this is not the case. Additionally, univariate analyses seldom show the Inuit samples to be more cold-adapted in body shape than Europeans, and multivariate cluster analyses that include a myriad of body shape variables such as femoral head diameter, bi-iliac breadth, and limb segment lengths fail to effectively separate the Inuit samples from Europeans. In fact, in terms of body shape, the European and the Inuit samples tend to be cold-adapted and tend to be separated in multivariate space from the more tropically adapted Africans, especially those groups from south of the Sahara. Am J Phys Anthropol 142:287-302, 2010. [ABSTRACT FROM AUTHOR]

The article presents a study which examines and compares the seasonality and sex differences in travel distance and resource transport of foragers in Venezuela. During the study, researchers, investigated the distances traveled and weights transported by individual Pumé men and women during food collection trips to assess the differential targeting of foods, the habitual physiological efforts of burden carrying, and the sexual division of labor in foragers. The study demonstrates that female foraging travel distances and food resource weights relative to individual body weights are greater than those of their male counterparts in certain food resources.

Causal mediation analysis has increasingly become a popular practice in various clinical trials and epidemiological applications to evaluate whether an intermediate variable is on the pathway between the exposure of interest and a response. Previous mediation analyses in the literature mainly focused on settings with a single or low-dimensional mediators and single-level data. In this article, we propose a Bayesian causal mediation analysis method that can handle our multilevel intergenerational epigenetic mechanisms study (IEMS) with high-dimensional mediators. Specifically, we develop a Bayesian hierarchical model for data with such complexity, and then employ the Bayesian spike-and-slab priors on the exposure-mediator-outcome effect pathway to identify active mediators involved in mediation. We derive the natural indirect and direct effects based on our hierarchical model and provide statistical inference based on Markov chain Monte Carlo (MCMC) methods. Our simulation study demonstrates that our proposed Bayesian method outperforms other alternative methods in various scenarios. We further illustrate the utility of our method to IEMS to assess the causal mechanisms between maternal exposure to climate extremes and offspring's growth outcomes through DNA methylation. [ABSTRACT FROM AUTHOR]

Objectives: To measure heavy metal concentrations among Kenyan youth and quantify associations with sociocultural, demographic, and health factors as well as anthropometry. Methods: Using data from a study of semi-nomadic pastoralists in Samburu County, Kenya, we measured blood concentrations of lead (Pb), mercury (Hg), and cadmium (Cd) in 161 adolescents. We identified sociocultural, demographic and health characteristics associated with each metal and quantified the association between metals and adolescent anthropometry. Results: Median blood concentrations of Pb, Cd, and Hg were 1.82 µg/dL, 0.24 µg/L and 0.16 µg/L, respectively. Place of residence (highlands vs lowlands) was a determinant of metal concentrations. Hg was inversely related to anemia, and metals were not associated with anthropometry. Conclusions: In this population of Samburu adolescents, median Pb and Cd blood concentrations were higher than other North American or European biomonitoring studies. These findings motivate further investigation into the environmental sources of metals in this community. [ABSTRACT FROM AUTHOR]

Recent decades have witnessed a growth in approaches to research and writing across anthropology's four fields that emphasize the need to respect alternative narratives and constructions of history, and to engage with anthropology's 'publics'. These developments have generated more ethically responsible research and more inclusive writing practices. Nevertheless, the actual doing of cross-cultural collaboration and knowledge production remains a challenge. In this three-field (cultural, biological, and archaeological anthropology) study, we aim to capture, in writing, a process of collaborative fieldwork with Samburu pastoralists in northern Kenya that experimentally integrated ethnographic self-scrutiny with a bio-archaeological excavation involving human remains. In the process, we highlight the reciprocal knowledge production that this cross-subdisciplinary, transcultural fieldwork produced. [ABSTRACT FROM AUTHOR]

Previous research in high-income countries suggests that children from families with lower socioeconomic status (SES) tend to have shorter telomere length – a biomarker of stress and cell aging – than children from families with greater social and economic resources. However, little is known about predictors of child telomere length in low-income settings. Data for the current study are from a sample of 214 Samburu children aged 1–9 years. The Samburu are semi-nomadic pastoralists who live in the Rift Valley of north-central Kenya. Samburu livelihood is based primarily on livestock, and polygynous marriage is common. Drawing on prior ethnographic research, we measured 14 culturally relevant indicators of family SES, including mother's education, head of household's education, whether the child is currently attending school, household spending, mother's employment history, head of household's employment history, mother's perceived wealth, whether the child lives in a modern house, livestock holdings (total, cows, sheep/goats, and camels), mother's wife number, and whether the child lives in a polygynous household. Telomere length was measured in salivary DNA by the quantitative polymerase chain reaction (qPCR) method. Using latent class analysis, we identified four groups of children that are similar based on the 14 indicators of family SES: Lower SES ; Middle SES, Traditional ; Middle SES, Modern ; and Higher SES. SES classes were not significantly associated with child telomere length. In models examining individual indicators of SES, we found that telomere length was 0.57 standard deviations greater for children who lived in families in the lowest quartile of total livestock holdings compared to those in the highest quartile (b = 0.57, p = 0.03). While additional research is needed to identify the mechanisms underlying this counterintuitive finding, the current study highlights the importance of cultural context in shaping the social gradient in health. • Telomere length is a biomarker of stress and cell aging. • Children in high socioeconomic status (SES) families tend to have longer telomeres. • In rural Kenya, total livestock holdings are inversely associated with child telomere length. • The social gradient in health depends on cultural context. [ABSTRACT FROM AUTHOR]

Although many studies relating stature to foot length have been carried out, the relationship between foot size and body mass remains poorly understood. Here we investigate this relationship in 193 adult and 50 juvenile habitually unshod/minimally shod individuals from five different populations—Machiguenga, Daasanach, Pumé, Hadzabe, and Samoans—varying greatly in body size and shape. Body mass is highly correlated with foot size, and can be predicted from foot area (maximum length × breadth) in the combined sample with an average error of about 10%. However, comparisons among populations indicate that body shape, as represented by the body mass index (BMI), has a significant effect on foot size proportions, with higher BMI samples exhibiting relatively smaller feet. Thus, we also derive equations for estimating body mass from both foot size and BMI, with BMI in footprint samples taken as an average value for a taxon or population, estimated independently from skeletal remains. Techniques are also developed for estimating body mass in juveniles, who have relatively larger feet than adults, and for converting between foot and footprint size. Sample applications are given for five Pliocene through Holocene hominin footprint samples from Laetoli (Australopithecus afarensis), Ileret (probable Homo erectus), Happisburgh (possible Homo antecessor), Le Rozel (archaic Homo sapiens), and Barcin Höyük (H. sapiens). Body mass estimates for Homo footprint samples appear reasonable when compared to skeletal estimates for related samples. However, estimates for the Laetoli footprint sample using the new formulae appear to be too high when compared to skeletal estimates for A. afarensis. Based on the proportions of A.L. 288-1, this is apparently a result of relatively large feet in this taxon. A different method using a ratio between body mass and foot area in A.L. 288-1 provides estimates more concordant with skeletal estimates and should be used for A. afarensis. [ABSTRACT FROM AUTHOR]