Quantifiable Cross-cultural Research on Medical Mistrust is Necessary for Effective and Equitable Vaccination in Low- and Middle-income Countries.

Perceptions of healthcare personnel and institutions substantially impact healthcare behaviors. In the US, minority experiences with racist events like the Tuskegee study, alongside everyday experiences of marginalization and discrimination, drive medical mistrust in populations that are already burdened with health inequalities. However, the concept of medical mistrust is rarely applied outside of industrialized contexts.

Remote sensing evidence for population growth of isolated indigenous societies in Amazonia.

Isolated indigenous societies who actively avoid sustained peaceful contact with the outside world are critically endangered. Last year, "Tanaru", the lone surviving man of his tribe for at least 35 years, died in Southwest Amazonia, marking the latest cultural extinction event in a long history of massacres, enslavement, and epidemics. Yet in the upper reaches of the Amazon Basin, dozens of resilient isolated tribes still manage to survive.

Only Death Will Separate Us: The Role of Extramarital Partnerships among Himba Pastoralists.

Extramarital partnerships are highly stigmatized in many societies and are typically excluded from studies of family dynamics and social support. Nevertheless, in many societies such relationships are common and can have important impacts on resource security and health outcomes. However, current studies of these relationships come mainly from ethnographic studies, with quantitative data extremely rare.

Resource demands reduce partner discrimination in Himba women.

Where autonomy for partner choice is high, partner preferences may be shaped by both social and ecological conditions. In particular, women's access to resources can influence both the type and number of partnerships she engages in. However, most existing data linking resources and partner choice rely on either priming effects or large demographic databases, rather than preferences for specific individuals.

Why men invest in non-biological offspring: paternal care and paternity confidence among Himba pastoralists.

Paternal investment is predicted to be a facultative calculation based on expected fitness returns and modulated by a host of social predictors including paternity uncertainty. However, the direct role of paternity confidence on the patterns of paternal investment is relatively unknown, in part due to a lack of research in populations with high levels of paternity uncertainty. Additionally, much of the work on paternity certainty uses cues of paternity confidence rather than direct assessments from fathers.

Patterns of paternal investment predict cross-cultural variation in jealous response.

Long-lasting, romantic partnerships are a universal feature of human societies, but almost as ubiquitous is the risk of instability when one partner strays. Jealous response to the threat of infidelity is well studied, but most empirical work on the topic has focused on a proposed sex difference in the type of jealousy (sexual or emotional) that men and women find most upsetting, rather than on how jealous response varies. This stems in part from the predominance of studies using student samples from industrialized populations, which represent a relatively homogenous group in terms of age, life history stage and social norms.

The disequilibrium of double descent: changing inheritance norms among Himba pastoralists.

Matrilineal systems in sub-Saharan Africa tend to co-occur with horticulture and are rare among pastoralists, with the causal arrow pointing from the introduction of cattle to the loss of matriliny. However, most work on this topic stems from either phylogenetic analyses or historical data. To better understand the shift from matrilineal to patrilineal inheritance that occurred among Bantu populations after the adoption of pastoralism, data from societies that are currently in transition are needed.

The influence of age- and sex-specific labor demands on sleep in Namibian agropastoralists.

Objective: To understand the basics of sleep quality in a pastoralist population and to explore predictors of this variation.

Design: Cross-sectional.

Setting: Northern Namibia, dry seasons of 2016 and 2017.

DHEA Modulates Immune Function: A Review of Evidence.

DHEA and DHEA-S have numerous associations with multiple aspects of immune function and are often characterized as beneficial and supportive of immunocompetence. However, closer inspection of these studies reveals confusion regarding the immunological components modified, the mechanisms of action, and degree of impact, and even whether these hormones even have direct action or are mediated by metabolites and interactions with other hormones and hormone receptors. Additionally, much of the research is conducted on rodent models using very high concentrations of hormone supplements, which may not be representative of the effects of these hormones in natural circulating concentrations, or may not translate to human physiology in a meaningful way.

A Survey of Perceived Effectiveness of Part 4 Maintenance of Certification.

Objectives: Evaluative assessment is needed to inform improvement of Part 4 Maintenance of Certification (MOC), a large-scale program that aims to improve physician knowledge, engagement, and skills in quality improvement (QI). We sought to determine if Part 4 MOC participation improves perceived educational and clinical outcomes by piloting a new physician survey.

Methods: We administered a new online survey (MOC Practice, Engagement, Attitude, and Knowledge Survey) to physicians at the beginning and end of a Part 4 MOC project sponsored by a pediatric hospital's American Board of Medical Specialties' portfolio program during 2015.

Short-term resource allocation during extensive athletic competition.

Objectives: Following predictions from life history theory, we sought to identify acute trade-offs between reproductive effort (as measured by psychological arousal) and somatic maintenance (via functional measures of innate immunity) during conditions of severe energetic imbalance.

Methods: Sixty-six male ultramarathon runners (ages 20 to 37 years) were sampled before and after a lengthy race. Saliva and sera were collected for testosterone and immunological analyses (hemolytic complement activity and bacterial killing ability).

Child fosterage and sex-biased nutritional outcomes among Namibian pastoralists.

Objectives: Across cultures, fosterage has been shown to impact child health. Contextual factors, such as the reason for fosterage and the relationship between foster parent and child, are known to magnify variance in nutritional outcomes for foster children. Another important, but less studied, factor is the role of gender.

Adrenal maturation, nutritional status, and mucosal immunity in Bolivian youth.

Objectives: Humans-and several other apes-exhibit a unique pattern of post-natal adrenal maturation; however, the causes and consequences of variation in adrenal development are not well understood. In this study, we examine developmental and age-related maturation of the adrenal gland (measured via dehydroepiandrosterone-sulfate [DHEA-S]) for potential life-history associations with growth and mucosal immunity in a rural population of immune-challenged Bolivian juveniles and adolescents.

Methods: Salivary DHEA-S, anthropometrics, and salivary mucosal immunity (secretory IgA [sIgA]) were measured in 171 males and females, aged 8-23.

The role of dehydroepiandrosterone on functional innate immune responses to acute stress.

The androgen dehydroepiandrosterone (DHEA) responds to stress activation, exhibits anti-glucocorticoid properties, and modulates immunity in diverse ways, yet little is known of its role in acute stress responses. In this study, the effects of DHEA and its sulfate ester DHEA-S on human male immune function during exposure to an acute stressor is explored. Variation in DHEA, DHEA-S, testosterone, and cortisol, along with bacterial killing assays, was measured in response to a modified Trier Social Stress test in 27 young adult males.

Dehydroepiandrosterone and multiple measures of functional immunity in young adults.

Objectives: Human immune function is strongly influenced by variation in hormone concentrations. The adrenal androgens dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulfate (DHEA-S) are thought to be beneficial to immune function and disease resistance, but physiologically interact with testosterone and cortisol. We predict that DHEA and DHEA-S will interact with these other hormones in determining immunological outcomes.

Androgens and innate immunity in rehabilitated semi-captive orangutans (Pongo pygmaeus morio) from Malaysian Borneo.

Despite the implications for the development of life-history traits, endocrine-immune trade-offs in apes are not well studied. This is due, in part, to difficulty in sampling wild primates, and lack of methods available for immune measures using samples collected noninvasively. Evidence for androgen-mediated immune trade-offs in orangutans is virtually absent, and very little is known regarding their pattern of adrenal development and production of adrenal androgens.

Accelerated diversification of nonhuman primate malarias in Southeast Asia: adaptive radiation or geographic speciation?

Although parasitic organisms are found worldwide, the relative importance of host specificity and geographic isolation for parasite speciation has been explored in only a few systems. Here, we study Plasmodium parasites known to infect Asian nonhuman primates, a monophyletic group that includes the lineage leading to the human parasite Plasmodium vivax and several species used as laboratory models in malaria research. We analyze the available data together with new samples from three sympatric primate species from Borneo: The Bornean orangutan and the long-tailed and the pig-tailed macaques.