Fujita, Dr. Masako, Michigan State U., East Lansing, MI - To aid research on 'The Impact of Maternal Nutrition and Infant Sex on Breast Milk Quality in Polygynous Ariaal Agro-pastoralists of Northern Kenya'
Preliminary abstract: The Trivers-Willard hypothesis (TWH) predicts unequal parental investment between daughters and sons in polygynous populations where somatic or economic conditions of males determine their marriageability. Specifically, it predicts that mothers in good condition will invest more in sons while mothers in poor condition will invest more in daughters because these strategies may enhance their reproductive success. A small but growing number of studies investigate sex bias in human milk quality, particularly milk nutrient levels with mixed results. This literature focuses on energy-yielding nutrients (e.g. fat, sugar) to test the hypothesis, and misses other nutritive and non-nutritive components of milk indispensable for infants to survive and thrive. The proposed study contributes by examining TWH, using breast milk vitamin (B9 or folate) and antibody (secretory immunoglobulin A or sIgA) as indicators of maternal investment. A cross-sectional random sample of breast milk specimens from 220 mothers of the Ariaal tribe, a polygynous population of rural Kenya, originally collected in 2006, cryogenically archived (-80°C), will be analyzed for the levels of folate-binding protein and sIgA. The resulting data will be used to statistically test the hypotheses: 1) maternal nutrition (e.g. adiposity, micronutrient status) will positively predict folate/sIgA, 2) this effect will be moderated by infant sex, and 3) there will be a TW effect, i.e. milk of under-nourished mothers will exhibit preference toward daughters and milk of other mothers toward sons. Findings will facilitate a multi-faceted view on possible sex bias in human milk components in a specific sociocultural and ecological context. This will contribute to the refined understanding of the conditional variation in human parental investment which has important implications for sex differences in infant growth and health in relation to different marriage rules.
Howells, Dr. Michaela, U. of North Carolina, Wilmington, NC - To aid engaged activities on 'Promoting Dialog Between Health Care Providers and Pregnant Women on American Samoa,' 2015, American Samoa
DR. MICHAELA HOWELLS, University of North Carolina, Wilmington, North Carolina, received funding in March 2015 to aid engaged activities on 'Promoting Dialog between Health Care Providers and Pregnant Women on American Samoa.' There is a lack of culturally salient, bilingual health education materials in American Samoa. The available education materials are mostly written in English and featured white people, a minority on island. According to the resident health care professionals, these materials failed to reflect Samoan culture and thus missed an important opportunity to educate women. As a result, the grantee launched a collaborative project between the women's health professionals in American Samoan Department of Health (DOH), Women Infant Child (WIC), and LBJ Tropical Medical Center (LBJ) - the island's only hospital. Together five educational posters were developed that focused on women's reproductive healthcare themes: prenatal care, high risk pregnancies, nutrition and exercise during pregnancy, birth control options, and breast feeding. After gaining their permission, the grantee took photos of pregnant Samoan women, Samoan babies, health care professionals, clinics, food, and community exercise and combined these with culturally appropriate colors and designs. Each draft was reviewed by the women's health care team, and these posters were printed and disseminated to the island's clinics. The creation of culturally relevant, long lasting, health care materials helps reinforce the connection between the prenatal care needs of Samoan women and the medical community that serves them.
McHale, Timothy Sean, U. of Nevada, Las Vegas, NV - To aid research on 'Investigating Acute Steroid Hormone Change in Response to Competition among Hong Kong Juvenile Boys,' supervised by Dr. Peter Gray
Preliminary abstract: The aim of the proposed research is to investigate steroid hormone response to physical and non-physical forms of male-male competition among juvenile boys in Hong Kong. The goal of this research is to provide novel insights into the proximate mechanisms that mediate competitive social behavior in boys and to assess the factors that potentially contribute to acute reactive changes of adrenal steroid hormones during juvenile development. Three independent research studies will be conducted during a 1) head-to-head table tennis tournament, 2) soccer match and soccer scrimmage, 3) and a math competition. Boys' before and after saliva samples will be collected to evaluate hypothalamic-pituitary-adrenal (HPA) axis activity, using biomarkers: dehydroepiandrosterone (DHEA), androstenedione, cortisol, and testosterone. Liquid chromatography--tandem mass spectrometry (LC-MS/MS) will be used to measure the hormone concentrations of the samples, the most technically sophisticated and accurate method of analysis available. I hypothesize that children may have evolved an endocrine pathway that is unique to the juvenile stage of development, such that DHEA and androstenedione, rather than testosterone, will acutely rise in order to meet the physical and cognitive demands of social competition. I predict that boys will experience acute increases in DHEA and androstenedione in all three studies. Additionally, I predict acute hormone changes will be associated with psychosocial variables, such as competitor type (in-group vs. out-group), self-reported individual performance, and outcome of the contest (victory/defeat). Testosterone is predicted to exert no measurable effects in all three studies.
Shirley, Meghan, U. College London, London, UK - To aid research on 'Body Composition and the Brain: Investigating Life History Trade-offs in Living Humans,' supervised by Dr. Jonathan Wells
Preliminary abstract: Energy resources in any given environment are finite. Life history theory examines trade-offs between competing functions such as maintenance and reproduction across an organism's life course. For early humans, the evolution of a metabolically expensive brain was likely associated with reorganized energy investment and/or alterations in life history strategy and behavior. Insight into how the human brain was afforded may be most readily achieved with attention directed to investment 'decisions' at the level of organs and tissues. For example, Aiello and Wheeler's (1995) 'expensive tissue' hypothesis proposed that a reduction in the size of the human gut enabled encephalization. Research has demonstrated tissue trade-offs in a range of animals, yet empirical studies of human investment strategies remain rare. With the collection of MRI and body composition data from healthy adults, this project will investigate trade-offs between the human brain and other 'expensive' tissues of the body, trade-offs between the brain and adipose tissue, and also positive brain-body phenotype associations. Further, the study will examine the effect of early life experience on phenotype. This data will add to knowledge of the variability with which modern humans 'strategically' manage energy investment and lead to more robust inferences concerning hominin life history evolution.
Garofalo, Evan Michele, Johns Hopkins U., Baltimore, MD - To aid research on 'Genetic and Environmental Effects on Skeletal Growth Variation,' supervised by Dr. Christopher Britton Ruff
EVAN M. GAROFALO, then a student at Johns Hopkins University, Baltimore, Maryland, received funding in May 2010, to aid research on 'Genetic and Environmental Effects on Skeletal Growth Variation,' supervised by Dr. Christopher Britton Ruff. Adult morphology and variation are the result of complex interactions between genetic and environmental effects during the growth process. Health, disease, and socio-economic status are important for the regulation of the growth trajectory, particularly during infancy and early childhood. However, genetic differences, increasing in prominence during adolescence, contribute significantly to growth profiles and the attainment of adult morphology. Thus, the primary goal of this project is to partition the relative importance of environmental and genetic influences on the timing and nature of the growth process. Multiple skeletal variables, each differentially sensitive to environmental and genetic influence, were examined to assess the skeletal growth of individuals from St. Peter's Church (Barton-upon-Humber, UK) -- a socially stratified and relatively genetically homogeneous population. In this study, there is no effect of socioeconomic status on long bone length, stature, body mass or articular dimensions. However, long bone diaphyseal cross-sectional cortical and medullary areas (considered to be highly environmentally sensitive) show marked differences, primarily during infancy and early childhood, with reduced or no differences for young adults. Early results and palaeopathological observations suggest socioeconomic groups differences may be related to sustaining more prolonged durations of metabolic distress in the higher socioeconomic subadult sample.
Howells, Michaela Emily, U. of Colorado, Boulder, CO - To aid research on 'The Impact of Psychosocial Stress on Gestation Length and Pregnancy Outcomes in American Samoa,' supervised by Dr. Darna Dufour
MICHAELA E. HOWELLS, then a student at University of Colorado, Boulder, Colorado, was awarded funding in April 2011 to aid research on 'The Impact of Psychosocial Stress on Gestation Length and Pregnancy Outcomes in American Samoa,' supervised by Dr. Darna Dufour. The objective of this research is to determine the relationship between chronic maternal psychosocial stress on spontaneous abortion, gestation length, and neonate body size. In order to achieve this goal, the grantee conducted a biocultural, longitudinal, prospective study of pregnancy outcomes in 184 women experiencing significant shifts in cultural identity in American Samoa. Two interrelated indicators of psychosocial stress -- Epstein-Barr virus (EBV) antibody concentration and status incongruence -- were paired with monthly maternal interviews to assess the effects of stress on pregnancy outcomes. EBV antibody concentrations represent a broad, non-specific response to psychosocial stressors. Status incongruence is related to a woman's status within the community and arises when an individual is unable to resolve traditional and nontraditional markers of status. This study follows from their first prenatal care appointment through to their pregnancies natural conclusion and will help clarify the effects of psychosocial stress on pregnancy outcomes. Pregnancy outcomes will be assessed in terms of neonate size for gestation. Possible outcomes include spontaneous abortions, preterm births (? 36 weeks) and full-term births. This study aims to add to our knowledge of the factors associated with pregnancy loss, premature delivery, and infants born small-for-gestational-age in a non-western population of women.
Melby, Dr. Melissa Kathleen, National Institute of Health and Nutrition, Tokyo, Japan - To aid research on 'Developmental Origins of Metabolic Syndrome: Study Utilizing the Japanese Maternal and Child Health Handbook'
DR. MELISSA K. MELBY, National Institute of Health and Nutrition, Tokyo, Japan was awarded a grant in October 2008 to aid research on 'Developmental Origins of Metabolic Syndrome: Study Utilizing the Japanese Maternal and Child Health Handbook.' The 'Developmental Origins of Health and Disease' hypothesis posits that in utero stress such as nutritional restriction resulting in low birth weight (LBW) increases later life risk of metabolic-syndrome related disease. Understanding risk factors for LBW thus has implications for later life health. Among singleton full-term births (N~437) in Japan, females were three times more likely to be born at LBW than males. For males, gestational length was the biggest predictor of LBW, but gestational length was not a significant predictor of female LBW. Instead maternal weight at first prenatal exam, and total gestational weight gain after that exam, were most predictive. For girls only, primiparity and maternal history of LBW babies also increased risk, while maternal height decreased risk. If given adequate time in the womb, male babies appear largely immune to early pre-natal or pre-conception maternal condition and low maternal gestational weight gain. Female babies appear to be very sensitive to maternal condition, particularly early/initial weight and weight gain, as well as reproductive history. BMI at age 6-7 appears independent of birth weight and maternal gestational weight gain for boys, while girls' age 6-7 BMI appears more dependent on reproductive history, gestational weight gain, and resulting birth weight.