- Award ID(s):
- 1728743
- NSF-PAR ID:
- 10340166
- Date Published:
- Journal Name:
- American journal of physical anthropology
- Volume:
- 178
- Issue:
- 4
- ISSN:
- 0002-9483
- Page Range / eLocation ID:
- 574-592
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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null (Ed.)Growing economic disparities and the increased sorting of families into economically segregated communities have heightened the need to clearly delineate pathways through which family income promotes children’s development. Combining hypotheses from investment and stress theories, we developed and tested a multi-context and cross-domain conceptual model assessing how community and family contexts mediate links between family income and children’s cognitive and behavioral skills at kindergarten entry. We drew data on family income, parenting processes, and child functioning from the Early Childhood Longitudinal Study– Birth Cohort (ECLS-B; N ≈ 10,650), following children from infancy through age 5. We used Geographic Information Systems technology to create and validate community measures using administrative data from the Economic Census, Decennial Census, National Center of Education Statistics, Federal Bureau of Investigations, and Environmental Protection Agency, which were then linked to each child in the ECLS-B. Using structural equation modeling, our analyses revealed three primary lessons. First, lower-income children have limited access to community educational and cultural resources and heightened exposure to community stressors including concentrated disadvantage and violent crime. Second, these community features are associated with parenting processes, such that parent-child interactions tend to be less stimulating and supportive and more punitive in communities with fewer resources and heightened stressors. And third, community and family contexts together mediate connections between family income and children’s cognitive and behavioral functioning. Results, albeit showing small effect sizes, provide a more complex, multi-contextual view than prior research, delineating the role of both resources and stressors at community and family levels in explaining income disparities in young children’s developmental success.more » « less
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Abstract Organisms are increasingly likely to be exposed to multiple stressors repeatedly across ontogeny as climate change and other anthropogenic stressors intensify. Early life stages can be particularly sensitive to environmental stress, such that experiences early in life can “carry over” to have long‐term effects on organism fitness. Despite the potential importance of these within‐generation carryover effects, we have little understanding of how they vary across ecological contexts, particularly when organisms are re‐exposed to the same stressors later in life. In coastal marine systems, anthropogenic nutrients and warming water temperatures are reducing average dissolved oxygen (DO) concentrations while also increasing the severity of naturally occurring daily fluctuations in DO. Combined effects of warming and diel‐cycling DO can strongly affect the fitness and survival of coastal organisms, including the eastern oyster (
Crassostrea virginica ), a critical ecosystem engineer and fishery species. However, whether early life exposure to hypoxia and warming affects oysters' subsequent response to these stressors is unknown. Using a multiphase laboratory experiment, we explored how early life exposure to diel‐cycling hypoxia and warming affected oyster growth when oysters were exposed to these same stressors 8 weeks later. We found strong, interactive effects of early life exposure to diel‐cycling hypoxia and warming on oyster tissue : shell growth, and these effects were context‐dependent, only manifesting when oysters were exposed to these stressors again two months later. This change in energy allocation based on early life stress exposure may have important impacts on oyster fitness. Exposure to hypoxia and warming also influenced oyster tissue and shell growth, but only later in life. Our results show that organisms' responses to current stress can be strongly shaped by their previous stress exposure, and that context‐dependent carryover effects may influence the fitness, production, and restoration of species of management concern, particularly for sessile species such as oysters. -
Abstract Objective Adrenarche, the biological event marked by rising production of dehydroepiandrosterone and its sulfate (DHEAS), may represent a sensitive period in child development, with important implications for adolescence and beyond. Nutritional status, particularly BMI and/or adiposity, has long been hypothesized as a factor in DHEAS production but findings are inconsistent, and few studies have examined this among non‐industrialized societies. In addition, cortisol has not been included in these models. We here evaluate effects of height‐ (HAZ), weight‐ (WAZ), and BMI‐ (BMIZ) for‐age on DHEAS concentrations among Sidama agropastoralist, Ngandu horticulturalist, and Aka hunter‐gatherer children.
Methods Heights and weights were collected from 206 children aged 2–18 years old. HAZ, WAZ, and BMIZ were calculated using CDC standards. DHEAS and cortisol assays were used to determine biomarker concentrations in hair. Generalized linear modeling was used to examine effects of nutritional status on DHEAS concentrations, as well as cortisol, controlling for age, sex, and population.
Results Despite the prevalence of low HAZ and WAZ scores, the majority (77%) of children had BMI
z ‐scores >−2.0 SD. Nutritional status has no significant effect on DHEAS concentrations, controlling for age, sex, and population. Cortisol, however, is a significant predictor of DHEAS concentrations.Conclusions Our findings do not support a relationship between nutritional status and DHEAS. Instead, results suggest an important role for stress and ecology in DHEAS concentrations across childhood. Specifically, effects of environment via cortisol may be influential to patterning of DHEAS. Future work should investigate local ecological stressors and their relationship to adrenarche.
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Abstract Introduction While many aspects of female ovarian function respond to environmental stressors, estradiol (E2) appears less sensitive to stressors than progesterone, except under extreme ecological conditions. However, earlier studies relied on saliva samples, considered less sensitive than blood. Here, we investigated E2 variation among 177 Bangladeshi and UK white women, aged 35–59, using single serum samples. Bangladeshi women either grew up in Sylhet, Bangladesh (exposed to poor sanitation, limited health care, and higher pathogen loads but not poor energy availability), or in the UK.
Methods We collected samples on days 4–6 of the menstrual cycle in menstruating women and on any day for post‐menopausal women. Participants included: (i) Bangladeshi sedentees (
n = 36), (ii) Bangladeshis who migrated to the UK as adults (n = 52), (iii) Bangladeshis who migrated as children (n = 40), and (iv) UK white women matched for neighborhood residence to the migrants (n = 49). Serum was obtained by venipuncture and analyzed using electrochemiluminescence. We collected anthropometrics and supplementary sociodemographic and reproductive data through questionnaires. We analyzed the data using multivariate regression.Results E2 levels did not differ between migrant groups after controlling for age, BMI, physical activity, psychosocial stress, parity, and time since last birth (parous women). Paralleling results from salivary E2, serum E2 did not differ among women who experienced varying developmental conditions.
Conclusion Our results reinforce the hypothesis that E2 levels are stable under challenging environmental conditions. Interpopulation variation may only arise under chronic conditions of extreme nutritional scarcity, energy expenditure, and/or high disease burdens.
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Cortisol, a key product of the stress response, has critical influences on degenerative aging in humans. In turn, cortisol production is affected by senescence of the hypothalamic–pituitary–adrenal (HPA) axis, leading to progressive dysregulation and increased cortisol exposure. These processes have been studied extensively in industrialized settings, but few comparative data are available from humans and closely related species living in natural environments, where stressors are very different. Here, we examine age-related changes in urinary cortisol in a 20-y longitudinal study of wild chimpanzees (
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