A note on Hardy-Weinberg equilibrium of VNTR data by using the Federal Bureau of Investigation''s fixed-bin method.

To fully utilize the information of VNTR data for forensic inference, the probability of observing the matching suspect and evidentiary profile in a reference population is estimated, usually by assuming independence of alleles within and between loci. This assumption has been challenged on the basis of the observation that there is frequently an excess of single-band phenotypes (SBP) in forensic data bases, which could indicate lack of independence. Nevertheless, another explanation is that the excess SBP are artifacts of laboratory methods. In this report we examine the excess of SBP for three VNTR loci studied by the FBI (D17S79 and D2S44, for blacks, and D14S13, for Caucasians). The FBI claims that the excess is due to the effect of null alleles; the null alleles are suspected to be too small to be detected. We estimate the frequency of null alleles for two loci (D17S79 and D14S13) by comparing, for these loci, the data from the FBI data base and the data from the Lifecodes data base. These comparisons yield information on small fragments because Lifecodes uses the restriction enzyme PstI, which yields larger fragments than does HaeIII, which the FBI uses. For D17S79 in blacks, we estimate a null allele frequency of 4.4%, and, for D14S13 in Caucasians, we estimate a frequency of 3.0%. The null-allele frequency for D2S44 in blacks is derived similarly, again being based on analyses of DNA cut with HaeIII and PstI; our estimate of the null-allele frequency for this locus is 1.5%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Measurement error in racial and ethnic statistics

In the United States, the racial and ethnic statistics published by the National Center for Health Statistics (NCHS) assume that each member of the U.S. population has a race and ethnicity and that if a member is black or white with respect to his risk of one disease, he is the same race with respect to his risk of another. Such an assumption is mistaken. Race and ethnicity are taken by the NCHS to be an intrinsic property of members of a population, when they should be taken to depend on interest. The actual or underlying race or ethnicity of members of a population depends on the risk whose variation within the population we wish to describe or explain.

Dynamics of ethnic and racial self-identification in contemporary Peru

This study has sought to analyse how the social and cultural dynamics of the population are expressed in the recent processes of ethnic self-identification in Peru. Data from 2012 to 2016 Peru National Household survey was used to investigate specifically: (a) on the contribution of the questions about ethnic and racial self-identification included in the National Household Survey to the visibility of indigenous and Afro-Peruvian populations; (b) on the individual and local characteristics related with certain self-identification categories; and (c) if the self-identification patterns have remained stable or have varied during the survey period. Results show that the number of persons who identifies as indigenous varies according to the question used. Likewise, it was found that characteristics such as age, migratory experience, education, and income level influence on the self-identification. Finally, modest but significant changes over time were registered, which could be shedding light on some processes of social transformations.     

VNTR polymorphism of the DRD4 locus in different Pakistani ethnic groups

The present study was designed to investigate the dopamine receptor D4 (DRD4) locus variable number of tandem repeat (VNTR) allelic distribution in different Pakistani ethnic groups. DNA samples from nine different ethnic groups of Pakistan were analyzed. Greek and Somali samples were included as representatives of the European and African populations, respectively. Pakistani, Greek, and Somali populations were also compared to the published data on different world populations. The allelic distribution revealed that the four-repeat allele was the most common allele in all the Pakistani ethnic groups as is in different other world populations, followed by the seven- and two-repeat alleles. To study the evolutionary relationship of the Pakistani ethnic groups among themselves and with a few other world populations, multidimensional scaling based on the allelic frequencies of the DRD4 VNTR was obtained. This analysis grouped most of the Pakistani ethnic groups together and closer to the European and Middle Eastern populations, except for the Mohanna from Sindh, who grouped with the African populations. In addition, the Somali and the Greek samples analyzed in this study grouped closer to the previous data obtained on the African and European populations, respectively.     

Inference of population subdivision from the VNTR distributions of New Zealanders

A population sample from people of diverse ethnic origins living in New Zealand serves as a database to test methods for inference of population subdivision. The initial null hypothesis, that the population sample is homogeneous across ethnic groups, is easily rejected by likelihood ratio tests. Beyond this, methods for quantifying subdivision can be based on the probability of drawing alleles identical by descent (F _ST ), probabilities of matching multiple locus genotypes, and occurrence of unique alleles. Population genetic theory makes quantitative predictions about the relation betweenF _ST , population sizes, and rates of migration and mutation. Some VNTR loci have mutation rates of 10^–2 per generation, but, contrary to theory, we find no consistent association between the degree of population subdivision and mutation rate. Quantification of population substructure also allows us to relate the magnitudes of genetic distances between ethnic groups in New Zealand to the colonization history of the country. The data suggests that the closest relatives to the Maori are Polynesians, and that no severe genetic bottleneck occurred when the Maori colonized New Zealand. One of the central points of contention regarding the application of VNTR loci in forensics is the appropriate means for estimating match probabilities. Simulations were performed to test the merits of the product rule in the face of subpopulation heterogeneity. Population heterogeneity results in large differences in estimates of multilocus genotype frequencies depending on which subpopulation is used for reference allele frequencies, but, of greater importance for forensic purposes, no five locus genotype had an expected frequency greater than 10^–6. Although this implies that a match with an innocent individual is unlikely, in a large urban area such chance matches are going to occur.Editor's commentsA side-benefit of the collection of DNA data from human populations is the light it may shed on human evolution. The authors discuss the colonization history of New Zealand in the light of such data. From a forensic viewpoint, too much should not be made of the differences between the major ethnic groups within New Zealand, as the forensic community in that country maintains separate databases for Caucasian, Maori and Pacific Islander (Buckletonet al., 1987). It will be of interest in the future to examine subdivision within these groups, as opposed to within the country as a whole. The authors' comments on testing for independence will need to read along with the findings of Zaykinet al. and Maiste and Weir in this volume. The authors had not seen the Budowleet al. (1994) rebuttal to the paper of Kraneet al. (1992).     

Teaching ethnic and racial relations: some comments on Michael Banton

Banton's critique of race and ethnic relations highlights differences between the U.K. and the U.S.A. The interplay between ethnic politics and the teaching of the subject in the universities reflects differing reactions to the demise of Marxism, the impact of globalization and the growth of transnationalism. In America, anthropology, economics, cultural studies and conflict resolution have had a mixed impact on the field, but an examination of textbooks over the past thirty years - as well as Banton's prolific scholarship - suggests that most of the core problems remain the same.     

Formation of ethnic and racial identities: narratives by young Asian-American professionals

This article examines Asian-American professionals’ ethnic and pan-ethnic attachments and identities through fifteen autobiographical essays. Classical assimilation theory predicts that well-educated Asian-American professionals will be highly acculturated into the white middle class, with little retention of their ethnic subculture; yet many of our essayists had strong, bicultural orientations. Their high level of social assimilation, reflected in their friendships and intimate relationships with whites, indicates that Asian Americans can socially assimilate without relinquishing their culture. Most of the 1.5 and second-generation essayists tried to hide their ethnic culture and non-white characteristics during their early school years. Yet, they experienced a painful but gradual establishment of an ethnic identity, usually beginning in their college years. Some contributors also expressed varying degrees of pan-Asian identity and a moderate level of Third World racial identity.     

Introduction: Framing difference: racial and ethnic studies in twentyfirst-century Britain

The events in Britain since the beginning of the new millennium starkly and dramatically reflect the continued salience of racial and ethnic difference. In media, political and academic discourse, the struggles over nationhood and multiculturalism, the duties of citizenship and the right to cultural expression, similarity and difference have been played out against global and national backdrops, and across many local stages. The articles in this volume aim to explore the contours of this changing terrain, and suggest new avenues for research and theorization. They are primarily an engagement with British debates and events, but seek to place these within a broader global and diasporic context. The aim of this introductory article is to sketch the background to the events that surround the production of these articles, to outline a broad conceptual overview of the current academic debates and to explore the links between each contribution.     

用RFLP标记分析甘蓝型油菜的遗传多样性

以甘蓝型油菜的２８个基因组探针和两种限制性内切酶对包括４６个中国品种、９个欧洲品种在内的５９个甘蓝型油菜品种（系）的ＲＦＬＰ标记进行了分析。在放射自显影胶片上,共检测到４１０条具多态性的分子杂交带,表明甘蓝型油菜中存在着极为丰富的遗传变异。聚类分析结果表明,在相似性为４５％的水平上,可把中国甘蓝型油菜划分为６组：胜利油菜组、跃进油菜组、中油８２１组、远缘种质组、优质油菜组和变异不详组。欧洲冬油菜与以上６组存在着较显著的遗传距离。主成分分析的结果与上述分组较为一致。以上结果表明,对于扩大中国甘蓝型油菜的遗传基础,欧洲冬油菜无疑是一个重要的种质资源。另一方面,用典型的中国甘蓝型油菜与欧洲冬油菜配制的杂交种,较易产生强大的杂种优势。从对已进行了染色体定位的６１条放射自显影带的分析看,无论是上述分组内,还是分组间,ＲＦＬＰ的相对差异均主要表现在Ａ基因组中。讨论了致使Ａ基因组遗传变异较大的可能因素。     

Identification of 57 conventional RFLP and 6 VNTR systems with 32 DNA clones on chromosome 11p15

Fifty-four clones containing human inserts were selected from a cosmid library constructed from a somatic cell hybrid containing chromosome 11p15.3-p15.5 as its only human complement. In 32 of these clones, 63 polymorphic systems were identified with a panel of restriction enzymes: 57 conventional RFLP systems and 6 highly polymorphic VNTR systems. Although we examined the cosmid with only seven enzymes, 18 clones (including 6 VNTRs) were polymorphic with three or more enzymes. The results suggested that DNA sequences on the peritelomeric region of chromosome 11p tend to be highly variable. Because these markers are highly informative, they will be excellent resources for investigations of hereditary diseases and tumor suppressor genes in this region of chromosome 11.     

A reassessment of frequency estimates of PvuII-generated VNTR profiles in a Finnish, an Italian, and a general U.S. Caucasian database: no evidence for ethnic subgroups affecting forensic estimates.

Recently, Krane et al. addressed the effect of estimating various target DNA profile frequencies in Finnish, Italian, and general U.S. Caucasian databases. They observed that, when using an "inappropriate ethnic," or noncognate, database (e.g., a Finnish target profile frequency estimated in an Italian database, and vice versa), estimates were less common than when the target profile frequencies were estimated using their own ethnic, or cognate, database, and these estimates differed by more than one order of magnitude. These differences were attributed to the effects of subgroups. We demonstrate that the differences can be ascribed to statistical artifacts that induce large biases and correlations. Additionally, we show that the differences of estimates of any specific DNA profile frequency based on allelic size frequencies from different databases become smaller when the fixed-bin rather than a +/- 2.5% floating-bin approach is used.     

Sequence analysis,frequency and ethnic distribution of VNTR polymorphism in the 5'-untranslated region of the human prostacyclin synthase gene (CYP8A1)

The prostacyclin synthase enzyme (CYP8A1, EC 5.3.99.4) is the unique member of family 8 in the cytochrome P450 superfamily. Inheritable interindividual differences in prostacyclin production may be implicated in the pathogenesis of human vascular diseases. Recently, we functionally characterized a variable number of tandem repeat (VNTR) polymorphism in the 5'-proximal regulatory region of CYP8A1. In this study, we extended the CYP8A1 VNTR polymorphism analysis using a panel of DNA samples from distinct ethnic populations: Tunisians, Gaboneses and French Caucasians. A total of nine VNTR were detected, three of which represent new variants in the CYP8A1 promoter region. Differences among the three ethnic panels in the frequency of the VNTR variants were observed. This study represents the first multi-population-based analysis of the frequency and distribution of VNTR polymorphism affecting the CYP8A1 promoter.     

The use of racial, ethnic, and ancestral categories in human genetics research

The global dispersal of anatomically modern humans over the past 100,000 years has produced patterns of phenotypic variation that have exerted—and continue to exert—powerful influences on the lives of individuals and the experiences of groups. The recency of our common ancestry and continued gene flow among populations have resulted in less genetic differentiation among geographically distributed human populations than is observed in many other mammalian species. Nevertheless, differences in appearance have contributed to the development of ideas about “race” and “ethnicity” that often include the belief that significant inherited differences distinguish humans. The use of racial, ethnic, and ancestral categories in genetics research can imply that group differences arise directly through differing allele frequencies, with little influence from socially mediated mechanisms. At the same time, careful investigations of the biological, environmental, social, and psychological attributes associated with these categories will be an essential component of cross-disciplinary research into the origins, prevention, and treatment of common diseases, including those diseases that differ in prevalence among groups.     

Determinants of racial/ethnic differences in blood pressure management among hypertensive patients

Background

Prior literature has shown that racial/ethnic minorities with hypertension may receive less aggressive treatment for their high blood pressure. However, to date there are few data available regarding the confounders of racial/ethnic disparities in the intensity of hypertension treatment.

Methods

We reviewed the medical records of 1,205 patients who had a minimum of two hypertension-related outpatient visits to 12 general internal medicine clinics during 7/1/01-6/30/02. Using logistic regression, we determined the odds of having therapy intensified by patient race/ethnicity after adjustment for clinical characteristics.

Results

Blacks (81.9%) and Whites (80.3%) were more likely than Latinos (71.5%) to have therapy intensified (P = 0.03). After adjustment for racial differences in the number of outpatient visits and presence of diabetes, there were no racial differences in rates of intensification.

Conclusion

We found that racial/ethnic differences in therapy intensification were largely accounted for by differences in frequency of clinic visits and in the prevalence of diabetes. Given the higher rates of diabetes and hypertension related mortality among Hispanics in the U.S., future interventions to reduce disparities in cardiovascular outcomes should increase physician awareness of the need to intensify drug therapy more agressively in patients without waiting for multiple clinic visits, and should remind providers to treat hypertension more aggressively among diabetic patients.     

Intraspecific body size frequency distributions of insects

Although interspecific body size frequency distributions are well documented for many taxa, including the insects, intraspecific body size frequency distributions (IaBSFDs) are more poorly known, and their variation among mass-based and linear estimates of size has not been widely explored. Here we provide IaBSFDs for 16 species of insects based on both mass and linear estimates and large sample sizes (n ≥ 100). In addition, we review the published IaBSFDs for insects, though doing so is complicated by their under-emphasis in the literature. The form of IaBSFDs can differ substantially between mass-based and linear measures. Nonetheless, in non-social insects they tend to be normally distributed (18 of 27 species) or in fewer instances positively skewed. Negatively skewed distributions are infrequently reported and log transformation readily removes the positive skew. Sexual size dimorphism does not generally cause bimodality in IaBSFDs. The available information on IaBSFDs in the social insects suggests that these distributions are usually positively skewed or bimodal (24 of 30 species). However, only c. 15% of ant genera are polymorphic, suggesting that normal distributions are probably more common, but less frequently investigated. Although only 57 species, representing seven of the 29 orders of insects, have been considered here, it appears that whilst IaBSFDs are usually normal, other distribution shapes can be found in several species, though most notably among the social insects. By contrast, the interspecific body size frequency distribution is typically right-skewed in insects and in most other taxa.