Eric Abella Roth

In poor families, mothers' milk is richer for daughters than sons: A test of Trivers–Willard hypothesis in agropastoral settlements in Northern Kenya

The Trivers-Willard hypothesis predicts the unequal parental investment between daughters and sons, depending on maternal condition and offspring reproductive potential. Specifically, in polygynous populations where males have higher reproductive variance than females, it predicts that mothers in good condition will invest more in sons, whereas mothers in poor condition will invest more in daughters. Previous studies testing this hypothesis focused on behavioral investment, whereas few examined biological investment. This study investigates the Trivers-Willard hypothesis on both behavioral and biological parental investment by examining breastfeeding frequencies and breast milk fat concentrations. Data from exclusively breastfeeding mothers in Northern Kenya were used to test hypotheses: Economically sufficient mothers will breastfeed sons more frequently than daughters, whereas poor mothers will breastfeed daughters more frequently than sons, and economically sufficient mothers will produce breast milk with higher fat concentration for sons than daughters, whereas poor mothers will produce breast milk with higher fat concentration for daughters than sons. Linear regression models were applied, using breastfeeding frequency or log-transformed milk fat as the dependent variable, and offsprings sex (son = 1/daughter = 0), socioeconomic status (higher = 1/lower = 0), and the sex-wealth interaction as the predictors, controlling for covariates. Our results only supported the milk fat hypothesis: infants sex and socioeconomic status interacted (P = 0.014, n = 72) in their relation with milk fat concentration. The model estimated that economically sufficient mothers produced richer milk for sons than daughters (2.8 vs. 1.74 gm/dl) [corrected] while poor mothers produced richer milk for daughters than sons (2.6 vs. 2.3 gm/dl). Further research on milk constituents in relation to offsprings sex is warranted.

Inuit Sex-Ratio Variation: Population Control, Ethnographic Error, or Parental Manipulation? [and Comments and Reply]

Historical censuses of Inuit (Canadian and North Alaskan Eskimos) often contain highly male-biased juvenile sex ratios that have been interpreted as evidence of female infanticide. We use model life tables to estimate elements of historic Inuit population structure missing from the censuses themselves and use these estimates to examine the major explanations for Inuit sexratio bias found in the literature. The argument hat sex-ratio bias is primarily an artifact of incorrect age assessment due to early marriage of females is not upheld, although this factor appears to account for some proportion of the bias. Psychological exklanations based on male dominance fail to explain variation among Inuit populations. Functional explanations that portray fe male infanticide as a form of population regulation or as a device for balancing the numbers of adult men and women are inconsistent with empirical evidence as well as ecological and evolutionary theory. We conclude that estimated rates of female infanticide (ranging from o to 40% and averaging 2i% for the ten populations analyzed) are best explained as consequences of parental efforts to match the number of sons with locally prevailing but regionally variable rates of sex-specific mortality and eco. nomic productivity. We argue that these findings have broad significance for the analysis of sex-specific parental investment in many human populations. The most glaring consequence of the struggle for existence is manifested in the way in which [the Netsilik] try to breed the greatest possible number of boys and the fewest possible girls. For it is solely economy that lies behind the custom that girls are killed at birth.... The reasoning that lies behind infanticide is as follows: A female infant is only a trouble and an expense to the household as long as she cannot make herself useful. But the moment she is able to help she is married and leaves her family; for it is the rule that the woman goes with the family into which she has married. For this reason they try to regulate births in order to get as many boys as possible. KNUD RASMUSSEN, The Netsilik Eskimos, I93I

Modeling rendille household herd composition

Previous analysis of Rendille household herd composition revealed a transition from camel to cattle ownership for sedentary impoverished Rendille pastoralists of northern Kenya. In an attempt to delineate determinants of livestock holdings, logistic regression analysis of 112 household herds from the Rendille settlement of Korr, Marsabit District, Kenya was undertaken. Results indicated that household wealth, measured in present livestock holdings, past drought losses, and livestock sales, formed better predictors of cattle ownership than did household characteristics pertaining to labor supply, wage earners, age-set membership, and birth order of household head. These results are discussed in light of pastoral strategies designed to minimize risk.

Community mapping and respondent-driven sampling of gay and bisexual men's communities in Vancouver, Canada

Literature suggests formative research is vital for those using respondent-driven sampling (RDS) to study hidden populations of interest. However, few authors have described in detail how different qualitative methodologies can address the objectives of formative research for understanding the social network properties of the study population, selecting seeds and adapting survey logistics to best fit the population. In this paper we describe the use of community mapping exercises as a tool within focus groups to collect data on social and sexual network characteristics of gay and bisexual men in the metropolitan area of Vancouver, Canada. Three key themes emerged from analysing community maps along with other formative research data: (1) connections between physical spaces and social networks of gay and bisexual men, (2) diversity in communities and (3) substance use linked to formation of sub-communities. We discuss how these themes informed the planning and operations of a longitudinal epidemiological cohort study recruited by RDS. We argue that using community mapping within formative research is a valuable qualitative tool for characterising network structures of a diverse and differentiated population of gay and bisexual men in a highly developed urban setting.

HIV Community Viral Load and Factors Associated With Elevated Viremia Among a Community-Based Sample of Men Who Have Sex With Men in Vancouver, Canada.

Background:We developed estimates of community viral load (VL) and risk factors for unsuppressed VL from a cross-sectional study of men who have sex with men (MSM) in Vancouver, Canada. Methods:MSM were recruited from February 25, 2012 to February 28, 2014 using respondent-driven sampling (RDS). Participants completed a computer-assisted self-interview questionnaire and a nurse-administered point-of-care HIV test. For HIV-positive participants, we conducted VL and CD4 cell counts. We used RDS-weighted analysis to obtain population estimates of key variables and multivariable logistic regression to examine factors associated with having a VL of ≥200 copies per milliliter among HIV-positive participants. Results:We recruited 719 participants, of whom 119 (16.6%) were seeds. Our estimate of the population prevalence of HIV was 23.4% [95% confidence interval (CI): 15.8% to 31.0%] after RDS adjustments. We estimated that 18.6% (95% CI: 8.8% to 30.4%) of HIV-positive MSM in Vancouver had a VL of ≥200 copies per milliliter. Having an unsuppressed VL was associated with non-white ethnicity [adjusted odds ratio (AOR) = 4.34; 95% CI: 1.67 to 11.1], an annual income of <

Intergenerational Sex as a Risk Factor for HIV Among Young Men Who Have Sex with Men: A Scoping Review

15,000 CAD (AOR = 6.43; 95% CI: 2.08 to 19.9), using gamma-hydroxy butyrate in the previous 6 months (AOR = 4.85; 95% CI: 1.79 to 13.2), unprotected anal intercourse with a known HIV-negative or an unknown serostatus partner (AOR = 3.13; 95% CI: 1.10 to 8.90), and disclosing ones HIV serostatus ≥50% of the time (AOR = 7.04; 95% CI: 1.01 to 49.1). Conclusion:Despite a high prevalence of HIV, we estimated that a small proportion of HIV-positive MSM have undiagnosed HIV and unsuppressed VL. Our results highlight the importance of continued work to address health inequities using a framework based on social determinants of health.

Including Online-Recruited Seeds: A Respondent-Driven Sample of Men Who Have Sex With Men

An emerging body of evidence suggests that intergenerational sexual partnerships may increase risk of HIV acquisition among young men who have sex with men (YMSM). However, no studies have comprehensively evaluated literature in this area. We applied a scoping review methodology to explore the relationships between age mixing, HIV risk behavior, and HIV seroconversion among YMSM. This study identified several individual, micro-, and meso-system factors influencing HIV risk among YMSM in the context of intergenerational relationships: childhood maltreatment, coming of age and sexual identity, and substance use (individual-level factors); family and social support, partner characteristics, intimate partner violence, connectedness to gay community (micro-system factors); and race/ethnicity, economic disparity, and use of the Internet (meso-system factors). These thematic groups can be used to frame future research on the role of age-discrepant relationships on HIV risk among YMSM, and to enhance public health HIV education and prevention strategies targeting this vulnerable population.

Benefits and constraints of intimate partnerships for HIV positive sex workers in Kibera, Kenya.

Background Technology has changed the way men who have sex with men (MSM) seek sex and socialize, which may impact the implementation of respondent-driven sampling (RDS) among this population. Initial participants (also known as seeds) are a critical consideration in RDS because they begin the recruitment chains. However, little information is available on how the online-recruited seeds may effect RDS implementation. Objective The objectives of this study were to compare (1) online-recruited versus offline-recruited seeds and (2) subsequent recruitment chains of online-recruited versus offline-recruited seeds. Methods Between 2012 and 2014, we recruited MSM using RDS in Vancouver, Canada. RDS weights were used with logistic regression to address each objective. Results A total of 119 seeds were used, 85 of whom were online-recruited seeds, to recruit an additional 600 MSM. Compared with offline-recruited seeds, online-recruited seeds were less likely to be HIV-positive (OR 0.34, 95% CI 0.13-0.88), to have attended a gay community group (AOR 0.33, 95% CI 0.12-0.90), and to feel gay community involvement was “very important” (AOR 0.16, 95% CI 0.03-0.93). Online-recruited seeds were more likely to ask a sexual partner’s HIV status always versus <50% of the time (AOR 5.21, 95% CI 1.17-23.23), to have watched the Pride parade (AOR 6.30, 95% CI 1.69-23.45), and to have sought sex online (AOR 4.29, 95% CI 1.53-12-12.05). Further, compared with recruitment chains started by offline-recruited seeds, recruits from chains started by online-recruited seeds (283/600, 47.2%) were less likely to be HIV-positive (AOR 0.25, 95% CI 0.16-0.40), to report “versatile” versus “bottom” sexual position preference (AOR 0.56, 95% CI 0.35-0.88), and to be in a relationship lasting >1 year (AOR 1.65, 95% CI 1.06-2.56). Recruits of online seeds were more likely to be out as gay for longer (eg, 11-21 vs 1-4 years, AOR 2.22, 95% CI 1.27-3.88) and have fewer Facebook friends (eg, 201-500 vs >500, AOR 1.69, 95% CI 1.02-2.80). Conclusions Online-recruited seeds were more prevalent, recruited fewer participants, but were different from those recruited offline. This may therefore help create a more diverse overall sample. Our work has shown the value of geosocial networking apps for aiding RDS recruitment efforts, especially when faced with slow participation uptake by other means. Understanding the degree to which networks interact will be an important next step in confirming the efficacy of online RDS recruitment strategies.

Street youth's life-course transitions

IntroductionResearch on the intimate partnerships of female sex workers (FSWs) tends to focus on the risks associated with these relationships. This paper takes as its starting point that the situation of FSWs is better understood by including knowledge of the benefits of their intimate partnerships. Specifically, we employ the conceptual framework provided by emergent research examining intimacy as a complex fusion of affective and instrumental dimensions among sex workers. This perspective allows us to frame information about FSWs’ intimate partnerships within a behaviour-structural approach that is helpful for identifying how intimate partnerships can be a source of both benefit as well as increased risk to FSWs.MethodsOur results are based on a mixed-methods study carried out in the summer of 2011 in Kibera, Kenya. We conducted face-to-face interviews (n=30) with a non-probability sample of FSWs stratified by age who self-identified as Human Immune Virus positive (HIV+). We asked about participants’ involvement in current and past intimate partnerships, and whether these relationships had a positive or negative impact on their health and well‒being.ResultsParticipants currently in intimate partnerships had fewer clients and thus lower incomes than those without intimate partnerships. Participants presently with partners were also more likely to receive some financial support from partners, to report lower intimate partner violence, and to narrate higher partner emotional support and greater assistance with medications. These participants were also more likely to have disclosed their sex work and HIV+ statuses to their partners. Intimate partnerships, on the other hand, showed increased risk of economic vulnerability and emotional dependence for FSWs. This became especially problematic for those participants in fragile relationships. Despite these variations, none of the differences between the two groups were statistically significant.ConclusionsIntimacy and transactional relations are bound up with one another and intersect with the structural realities and vulnerabilities; this is the case for sex workers in well-resourced and resourced-constrained countries alike. Rather than treating intimate partnerships as distinct from transactional relationships, FSWs’ relationships should be viewed on a continuum of risk and support.

Sexual identity and drug use harm among high-risk, active substance users

Social science and media depictions of youth living on our city streets typically focus on their “risk behaviours,” especially illicit drug use and unprotected sex, the social environmental challenges they face, in particular higher likelihood of sexual and physical assault and homicide (Tyler, Hoyt, & Whitbeck, 2000; Auerswald & Eyre, 2002; Pedersen & Hegna, 2003; Brooks, Milburn, Rotheram, & Witkin, 2004; Ensign & Bell, 2004; Raleigh-DuRoff, 2004; Hyde, 2005; Witkin et al., 2005) and their delinquent/criminal behaviour (Hartnagel, 1998). This focus on the multiple “risks” that street youth face has been accompanied by the search for determinants of the risk factors for street involvement, such as parental substance abuse and child neglect. Female street youth have been depicted as particularly vulnerable, partly because once on the street, they come under the control of male recruiters who make the girls drug-dependent and force them into trading sexual favours for money or in-kind goods. According to Bagley and Young (1987, p. 23), “the girl who finally tries prostitution is one who is already degraded and demoralized, in a state of psychological bondage, with grossly diminished self-confidence.” Adults who exploit these female street youth are believed to take advantage of their feelings of disconnectedness and low self-esteem and isolation (Silbert & Pines, 1981, 1982a, 1982b) and addiction to substances (Green & Goldberg, 1993). Yet, many females who were victims of childhood physical and sexual abuse do not end up on the street, nor do all those who were abused and end up on the street (male as well as female) become involved in prostitution, and, finally, many males and females who become involved in prostitution have no history of early abuse (Hagan & McCarthy, 1997).