Whose Tangle is it Anyway? The African‐American Family,Poverty and United States Kinship

The comparison between United States immigrant and African‐American families presented by Daniel Patrick Moynihan in his 1965 report to President Lyndon Johnson remains the most popular folk model for explaining success, failure and mutual aid in poverty. Despite being savaged by social science in its first two decades and largely ignored in the last two, the Moynihan model is an enduring part of popular discourses on race, intensified by contemporary immigrant success narratives. Based on over three years of participant observation research among homeless African‐American and Latino men and their families and Latin‐American immigrants engaging in small business creation in New York City, I argue that Moynihan's empirically valid claim that certain immigrant family forms are more suited to mutual aid in crisis is misused to present the African‐American family as dysfunctional when its kinship norms are actually typically American.     

Ethnically mismatched cord blood transplants in African Americans: the Saint Louis Cord Blood Bank experience

BACKGROUND: For ethnic minority patients where a suitably matched BM or peripheral blood donor is frequently unavailable, cord blood offers an opportunity for hematopoietic stem cell transplantation. Focused recruitment of ethnic minorities for cord blood donation has been proposed as the preferred strategy to improve access for minority recipients to cord blood for transplantation. The aim of this study was to evaluate cord blood characteristics for Caucasian and African American donors and the success of ethnically mismatched UC blood transplantation in African American recipients. METHODS: Retrospective data analysis was performed comparing the characteristics of 556 cord blood units from African American and Caucasian donors. The outcomes of 18 African American ethnically mismatched transplant recipients were compared with a paired sample of 18 ethnically matched Caucasian recipients. RESULTS: The fraction of collected units meeting acceptability criteria from African Americans was significantly lower compared with Caucasians (P = <0.0001). Additionally, African Americans had a significantly lower post-processing total nucleated cell count (TNC) compared with Caucasians (P=0.007) but there were no other significant differences in conventionally measured product characteristics. In the transplant analysis, there was no difference in overall survival at 1 year (P=0.85) or time to neutrophil engraftment (P=0.92) between the two patient populations. DISCUSSION: At comparable levels of TNC dose and HLA matching, the use of ethnically mismatched UC blood units as a source for allogeneic unrelated transplant can result in successful transplant outcomes for African American patients.     

Differences in Resting Metabolic Rate between White and African‐American Young Adults

Objective: A reported lower resting metabolic rate (RMR) in African‐American women than in white women could explain the higher prevalence of obesity in the former group. Little information is available on RMR in African‐American men. Research Methods and Procedures: We assessed RMR by indirect calorimetry and body composition by DXA in 395 adults ages 28 to 40 years (100 African‐American men, 95 white men, 94 African‐American women, and 106 white women), recruited from participants in the Coronary Artery Risk Development in Young Adults (CARDIA), Birmingham, Alabama, and Oakland, California, field centers. Results: Using linear models, fat‐free mass, fat mass, visceral fat, and age were significantly related to RMR, but the usual level of physical activity was not. After adjustment for these variables, mean RMR was significantly higher in whites (1665.07 ± 10.78 kcal/d) than in African Americans (1585.05 ± 11.02 kcal/d) by 80 ± 16 kcal/d (p < 0.0001). The ethnic × gender interaction was not significant (p = 0.9512), indicating that the difference in RMR between African‐American and white subjects was similar for men and women. Discussion: RMR is ～5% higher in white than in African‐American participants in CARDIA. The difference was the same for men and women and for lean and obese individuals. The prevalence of obesity is not higher in African‐American men than in white men. Because of these reasons, we believe that RMR differences are unlikely to be a primary explanation for why African‐American women are more prone to obesity than white women.     

Cortical bone remodeling rates in a sample of African American and European American descent groups from the American Midwest: comparisons of age and sex in ribs

This study employs regression analysis to explore population and sex differences in the pattern of age-associated bone loss, as reflected by histomorphometric variables that are measures of intracortical and endocortical bone remodeling. A comparison of an African American sample from the Washington Park Cemetery in St. Louis, Missouri, and a European American rib sample composed of cadavers, autopsies, and forensic cases from Missouri reveals the existence of complex age-associated patterns for differences in measures of intracortical remodeling and cortical area. Females from the two samples express similar bone dimensions and dynamics. The African American females appear to lose more bone than their male counterparts, but this difference is absent in the European American sample. When age-associated patterns are considered, it is in the younger cohorts that African Americans exhibit greater relative cortical area than European Americans, but this is reversed in the older ages, when the latter group manifests greater bone mass. The European American males consistently differ in the slopes and intercepts for the variables compared to the other groups, and differences are highly significant with African American females, with the former group maintaining bone mass while the latter exhibit a more rapid bone loss. Achieving larger relative cortical area due to smaller endosteal area, coupled with better bone quality due to lower intracortical porosity early in life, may be a mechanism by which African Americans, especially females, maintain adequate bone mass in older ages, which buffers them from bone loss and related fragility fractures despite higher rates of intracortical remodeling and endosteal expansion later in life. These results suggest that both genetic and environmental factors are responsible for the differences in bone remodeling and bone mass observed between these samples.     

Genetic differentiation between American and European Drosophila melanogaster populations could be attributed to admixture of African alleles

A total of 48 polymorphic microsatellite loci were characterized in 13 Drosophila melanogaster populations originating from Europe, America, and Africa. Consistent with previous results, the African D. melanogaster populations were the most differentiated populations and harbored most variation. Despite an overall similarity, American and European populations were significantly differentiated. Interestingly, genetic distances based on the proportion of shared alleles as well as FST values suggested that the American D. melanogaster populations are more closely related to the African populations than European ones are. We also detected a higher proportion of putative African alleles in the American populations, indicating recent admixture of African alleles on the American continent.     

Associations of Fat Distribution and Obesity with Hypertension in a Bi‐ethnic Population: The ARIC Study

Objective: To examine associations of hypertension with obesity and fat distribution among African American and white men and women. Research Methods and Procedures: The analysis sample included 15,063 African American and white men and women between the ages of 45 and 64 years who were participants in the 1987 through 1989 examination of the Atherosclerosis Risk in Communities Study (ARIC). Odds ratios and adjusted prevalences of hypertension were calculated across sexspecific quintiles of body mass index (BMI), waist‐to‐hip ratio (WHR), waist circumference, and waist‐to‐height ratio (waist/height) and adjusted for age, research center, smoking, education, physical activity, alcohol consumption, hormone replacement therapy, and menopausal status. Results: The prevalence of hypertension was higher among African Americans than whites. In the lowest quintile of BMI, 41% of African American women and 43% of African American men had hypertension compared with 14% of white women and 19% of white men. Elevated BMI, WHR, waist circumference, and waist/height were associated with increased odds of hypertension in African American and white men and women. In women, but not in men, there were significant interactions between ethnicity and the anthropometric variables studied here. The direction of the interaction indicated larger odds ratios for hypertension with increasing levels of anthropometric indices in white compared with African American women. Discussion: Obesity and abdominal fat preponderance were associated with increased prevalence of hypertension in African American and white men and women. Associations were similar among African American and white men, but obesity and fat patterning were less strongly associated with hypertension in African American than in white women.     

Resemblance for Body Mass Index in Families of Obese African American and European American Women

Objective: We determined the levels of resemblance in body mass index (BMI) in large samples of families selected through obese African American and European American women. Research Methods and Procedures: We examined correlations among relatives in 1185 European American and African American families ascertained through age-matched obese women (BMI ≥ 30 kg/m²). A subset of 801 families were ascertained through extremely obese women (BMI ≥ 40 kg/m²). Results: Parent-offspring and sibling correlations ranged from 0.19 to 0.15, suggesting a moderate level of heritability in both groups. Mean BMI values for female relatives were lower for European Americans than for African Americans even though probands were matched, perhaps because the European American relatives regress to a lower population mean. We found significantly higher family correlations for height in European Americans, suggesting greater environmental variability among African Americans for factors affecting growth and physical development. Discussion: Our results suggest a similar level of heritability of BMI in families of obese African American and European American women. Other genetic studies will be needed to determine the extent to which the same or different genes and environmental conditions contribute to an overall similar heritability in the two racial groups.     

Pediatric paradox: heterogeneity in the birth cohort

Comparisons of birth-weight-specific infant mortality indicate that low-birth-weight African American infants have lower mortality than low-birth-weight European American infants despite higher infant mortality overall-the "pediatric paradox." One explanation is heterogeneity in birth weight. Analyses of African American and European American births suggest that birth cohorts consist of two heterogeneous subpopulations. One appears to account for normal births, whereas the other may consist of compromised births. Estimates of infant mortality indicate that the compromised subpopulation has higher overall mortality but lower birth-weight-specific mortality. We attribute lower birth-weight-specific infant mortality in the compromised subpopulation to higher rates of fetal loss. Compared to European American birth cohorts, African American birth cohorts have (1) higher birth-weight-specific mortality in the normal subpopulation, (2) larger compromised subpopulations, and (3) lower birth-weight-specific mortality in the compromised subpopulation. Consequently, the pediatric paradox is attributable to greater rates of compromised pregnancies and higher fetal losses among African Americans.     

Three novel mtDNA restriction site polymorphisms allow exploration of population affinities of African Americans

To develop informative tools for the study of population affinities in African Americans, we sequenced the hypervariable segments I and II (HVS I and HVS II) of mitochondrial DNA (mtDNA) from 96 Sierra Leoneans; European Americans; rural, Gullah-speaking African Americans; urban African Americans living in Charleston, South Carolina; and Jamaicans. We identified single nucleotide polymorphisms (SNPs) exhibiting ethnic affinities, and developed restriction endonuclease tools to screen these SNPs. Here we show that three HVS restriction site polymorphisms (RSPs), EcoRV, FokI, and MfeI, exhibit appreciable differences in frequency (average delta = 0.4165) between putative African American parental populations (i.e., extant Africans living in Sierra Leone and European Americans). Estimates of European American mtDNA admixture, calculated from haplotypes composed of these three novel RSPs, show a cline of increasing admixture from Gullah-speaking African American (m = 0.0300) to urban Charleston African American (m = 0.0689) to West Coast African American (m = 0.1769) populations. This haplotype admixture in the Gullahs is the lowest recorded to date among African Americans, consistent with previous studies using autosomal markers. These RSPs may become valuable new tools in the study of ancestral affinities and admixture dynamics of African Americans.     

Marriage promotion and missing men: African American women in a demographic double bind

Since 1996, state legislators, members of the U.S. Congress, and more recently President George W. Bush, have called for the protection of monogamous, heterosexual marriage and the promotion of marriage among poor women. The thrust of this policy making is directed at African American families, among which female headship doubled between 1965 and 1990. This doubling is temporally associated with enacting the legislation directed toward the War on Drugs, which resulted in a tripling of the African American prison population. In Syracuse, New York, the swelling African American population behind bars has resulted in a skewed sex ratio, in which women significantly outnumber men. The authors use national, state, and local epidemiological, environmental, and ethnographic data to argue that the proliferation of marriage-promotion policies is heterosexist and blames African American women for demographic realities over which they have little control.     

Urban Low-Income African American Men, HIV/AIDS, and Gender Identity

In a 1993 Human Organization article, Jerome Wright called for more research on African American male sexual behavior and the risk for HIV infection. The present article is a response to that call. Wright pointed out a well-known fact of HIV/AIDS prevention programs: such programs have not been very successful in reaching low-income African American males. The present article suggests that perhaps the key to better understanding sex-related health-risk behavior is to conduct more systematic research on gender identity, and the historical and sociocultural origins of such identities. I argue that if we are truly interested in developing effective HIV/AIDS programs targeting low-income African American males, then the sociocultural "meanings" that this population attaches to AIDS-related phenomena must be understood in the broader contexts of American constructs of masculinity, and in the real and perceived experiences of black men in America. Data from several ethnographic and qualitative research projects carried out among low-income African American male and female residents of Baltimore, other parts of Maryland, and Washington, D.C. are used in support of my primary arguments. [HIV/AIDS, African American Males, Gender Constructs, Sociocultural Meaning, Plantation America]     

Contrasting the ancestry patterns of three distinct population groups from the northernmost region of South America

Colombia, located in the north of the South American subcontinent is a country of great interest for population genetic studies given its high ethnic and cultural diversity represented by the admixed population, 102 indigenous peoples and African descent populations. In this study, an analysis of the genetic structure and ancestry was performed based on 46 ancestry informative INDEL markers (AIM-INDELs) and considering the genealogical and demographic variables of 451 unrelated individuals belonging to nine Native American, two African American, and four multiple ancestry populations. Measures of genetic diversity, ancestry components, and genetic substructure were analyzed to build a population model typical of the northernmost part of the South American continent. The model suggests three types of populations: Native American, African American, and multiple ancestry. The results support hypotheses posed by other authors about issues like the peopling of South America and the existence of two types of Native American ancestry. This last finding could be crucial for future research on the peopling of Colombia and South America in that a single origin of all indigenous communities should not be assumed. It then would be necessary to consider other events that could explain their genetic variability and complexity throughout the continent.     

β2-Adrenergic receptor polymorphisms: pharmacogenetic response to bronchodilator among African American asthmatics

Beta2-adrenergic receptor (beta2AR) gene polymorphisms have been reported to be associated with various asthma-related traits in different racial/ethnic populations. However, it is unknown whether beta2AR genetic variants are associated with asthma in African Americans. In this study, we have examined whether there is association between beta2AR genetic variants and asthma in African Americans. We have recruited 264 African American asthmatic subjects and 176 matched healthy controls participating in the Study of African Americans, Asthma, Genes and Environments (SAGE). We genotyped seven known and recently identified beta2AR SNP variants, then tested genotype and haplotype association of asthma-related traits with the beta2AR SNPs in our African American cohort with adjustment of confounding effect due to admixture background and environmental risk factors. We found a significant association of the SNP -47 (Arg-19Cys) polymorphism with DeltaFEF(25-75), a measure of bronchodilator drug responsiveness, in African American asthmatics after correction for multiple testing (P = 0.001). We did not observe association of the SNP +46 (Arg16Gly) variant with asthma disease diagnosis and asthma-related phenotypes. In contrast to previous results between the Arg16Gly variant and traits related to bronchodilator responsiveness, our results indicate that the Arg-19Cys polymorphism in beta upstream peptide may play an important role in bronchodilator drug responsiveness in African American subjects. Our findings highlight the importance of investigating genetic risk factors for asthma in different populations.     

The number of vertebrae in the Southern African Negro,the American Negro and the Bushman (San)

The numbers of precoccygeal vertebrae (PCV) are compared in Southern African Negroes, Bushman (San) and American Negroes. The S.A. Negro and San males have an exceptionally high frequency of an increased total PCV number whilst the frequencies are significantly lower in a combined Caucasoid sample and the Mongoloid samples. The American Negro male, too, has a high frequency but not as high as in S.A. Negroes. The high frequency of increased PCV number in San, S.A. Negroes and American Negroes is in keeping with the view that the Khoisan peoples (here represented by the San), the Southern African Negroes and the African ancestors of American Blacks sprang from a common proto-negriform stock. Males have a significantly greater frequency of increased PCV to 30 or 31, whereas females are more likely to have a decreased number of 28 PCV. This sex difference is present in all the populations studied.     

A genomewide admixture map for Latino populations

Admixture mapping is an economical and powerful approach for localizing disease genes in populations of recently mixed ancestry and has proven successful in African Americans. The method holds equal promise for Latinos, who typically inherit a mix of European, Native American, and African ancestry. However, admixture mapping in Latinos has not been practical because of the lack of a map of ancestry-informative markers validated in Native American and other populations. To address this, we screened multiple databases, containing millions of markers, to identify 4,186 markers that were putatively informative for determining the ancestry of chromosomal segments in Latino populations. We experimentally validated each of these markers in at least 232 new Latino, European, Native American, and African samples, and we selected a subset of 1,649 markers to form an admixture map. An advantage of our strategy is that we focused our map on markers distinguishing Native American from other ancestries and restricted it to markers with very similar frequencies in Europeans and Africans, which decreased the number of markers needed and minimized the possibility of false disease associations. We evaluated the effectiveness of our map for localizing disease genes in four Latino populations from both North and South America.     

Tracing the geographical origin of Megastigmus transvaalensis (Hymenoptera: Torymidae): an African wasp feeding on a South American plant in North America

Determining the geographical origin of an introduced organism can be critical to understanding or managing a non-native species, but is often difficult when the organism is small or inconspicuous. We used a phylogeographical approach to identify the region of endemism and determine the geographical origin of world populations of the seed-feeding wasp Megastigmus transvaalensis (Hussey). This wasp feeds on African Rhus species and South American Schinus species in various locations around the world. Because it is present both in Africa and in South America, it is unclear whether the wasp was originally an African Rhus-feeder that has begun feeding on Schinus or a South American Schinus-feeder that has started feeding on Rhus. Phylogenetic analysis of 800 bp of mitochondrial cytochrome oxidase I sequence data found extensive variation and phylogeographical structure within African M. transvaalensis. Specimens from other locations around the world were all identical in COI sequence and were phylogenetically nested within the African samples. We conclude that M. transvaalensis was originally an African Rhus-feeder that readily attacks Schinus. We evaluate potential pathways of introduction of this wasp to the New World, and we discuss implications of our results for biocontrol efforts against invasive Schinus populations.     

Excavating Culture: Ethnicity and Context as Predictors of Parenting Behavior

Ethnic, socioeconomic, and contextual predictors of parenting and family socialization practices were examined among African American and European American families. This is one of a set of coordinated studies presented in this special issue (Le et al.). With the goal of sampling African American and European American children and families that were roughly equivalent on socioeconomic indicators, 103 mothers and their children were interviewed when the children were in kindergarten, and 83.5% were interviewed again in fourth grade. There were no ethnic differences in mothers' reports of warmth and communication at kindergarten; mothers' and children's reports of behavioral control at fourth grade, and children's reports of warmth at fourth grade. Among the ethnic differences in the parenting constructs, a number of them were related to cultural variables. For example, African American mothers expressed higher levels of self-efficacy and this was positively related to beliefs in communicating ethnic pride in their children. Similarly, although African American mothers expressed lower levels of warmth than European American mothers at fourth grade, among African American mothers, warmth was positively related to ethnic pride and beliefs in ethnic equality. A similar pattern was found for Psychological Control at fourth grade. When parenting practices among African Americans are examined in relation to ethnic socialization goals and ethnic identity, endorsement of ethnic socialization and identity was associated with more adaptive parenting practices. Longitudinally, there were several notable changes in ethnic differences in parenting practices across age.     

Interaction of 5HTTLPR and Marijuana Use on Property Offending

This study uses data from the National Longitudinal Study of Adolescent Health to examine whether a polymorphism in the serotonin transporter gene (5HTTLPR) moderates the effects of marijuana use on property offending. The results reveal that 5HTTLPR interacts with marijuana use to predict significantly higher levels of property offending for African American females. The interaction coefficient is not statistically significant for Caucasian males, African American males, or Caucasian females. These findings suggest that marijuana use is associated only with higher levels of property offending among African American females who carry one or more copies of the 5HTTLPR short allele.     

CYP3A4-V and prostate cancer in African Americans: causal or confounding association because of population stratification?

CYP3A4-V, an A to G promoter variant associated with prostate cancer in African Americans, exhibits large differences in allele frequency between populations. Given that the African American population is genetically heterogeneous because of its African ancestry and subsequent admixture with European Americans, case-control studies with African Americans are highly susceptible to spurious associations. To test for association with prostate cancer, we genotyped CYP3A4-V in 1376 (2 N) chromosomes from prostate cancer patients and age- and ethnicity-matched controls representing African Americans, Nigerians, and European Americans. To detect population stratification among the African American samples, 10 unlinked genetic markers were genotyped. To correct for the stratification, the uncorrected association statistic was divided by the average of association statistics across the 10 unlinked markers. Sharp differences in CYP3A4-V frequencies were observed between Nigerian and European American controls (0.87 and 0.10, respectively; P<0.0001). African Americans were intermediate (0.66). An association uncorrected for stratification was observed between CYP3A4-V and prostate cancer in African Americans (P=0.007). A nominal association was also observed among European Americans (P=0.02) but not Nigerians. In addition, the unlinked genetic marker test provided strong evidence of population stratification among African Americans. Because of the high level of stratification, the corrected P-value was not significant (P=0.25). Follow-up studies on a larger dataset will be needed to confirm whether the association is indeed spurious; however, these results reveal the potential for confounding of association studies by using African Americans and the need for study designs that take into account substructure caused by differences in ancestral proportions between cases and controls.