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The nucleotide sequences of intron 6 were determined for two chimpanzee species to assess gene diversity among ABO blood group genes. Results are presented.

Research was conducted to examine the structural and magnetic characteristics of DyCo10Mo(sub 2-x)Si(sub x) compounds. The substitution of Mo and Si for Co in DyCo10Mo(sub 2-x)Si(sub x) yielde the maximum Curie temperature at x = 1.5. The spin reorientation occurring in the compound at low temperature was associated with the change of the easy-magnetization direction from the c axis to a conical arrangement as the temperature was decreased.

The Samoan islands were politically separated into American Samoa and Western Samoa in the early 1900s. Economic modernization is far more extensive in American Samoa. However, the Samoan archipelago has maintained a remarkable degree of sociocultural homogeneity, including intermarriage. The sociocultural exchanges presumably led to genetic homogeneity between the two Samoas. Detailed genetic comparisons and characterizations of Samoans are scanty, however. As part of a multidisciplinary study of modernization and cardiovascular risk factors in adults, we analyzed nine hypervariable nuclear DNA (HVR) and four serum protein polymorphisms in the two Samoan groups. The average heterozygosities at both DNA and serum protein loci are comparable in the two groups. As expected, the HVR loci reveal a high degree of variability (heterozygosity 30-87%) compared with the serum protein loci (heterozygosity 1-52%). A large proportion of alleles at the HVR loci, ranging from 50% to 100%, are shared between American and Western Samoa. With the exceptions of the D1S80 locus in American Samoa and the D13S118 locus in Western Samoa, the genotype distributions at all loci conform to their respective Hardy-Weinberg expectations. Sporadic occurrence of the F13B*2 allele at the F13B locus in Samoans indicates a low level of European admixture because this allele is unique to Europeans. The calculated zero values of kinship coefficients and standard genetic distances indicate minimal population differentiation between the two Samoan groups., Samoans form one of the largest and most culturally distinct communities of Polynesia, and the Samoan islands have long been considered an important center of Polynesian culture. As a result [...]

The existence of new pseudo-binary Fe-rich NdFe(sub 13-x)Be(sub x) phase (x = 2,3) with a NaZn(sub 13) type structure is reported. A quantum design SQUID magnetometer is used to measure the magnetic properties in the 5 K-350 K range in fields up to 5.5 T and a vibrating sample magnetometer is used to measure the magnetic ordering temperatures.

Hispanics show twice the prevalence oftype 2 diabetes (NIDDM) as non-Hispanic whites. The causes of this difference in prevalence remain elusive, but undoubtedly, environmental and genetic risk factors, as well as gene-environment interactions are involved in the observed variation in diabetes risk. Previous studies have shown a remarkable correlation between NIDDM and the percentage of Native American ancestry in several North American populations. This correlation has been explained in terms of the presence of risk alleles of Native American ancestry in these populations. In this study, we have analyzed the pattern and dynamics of admixture in a sample of diabetics and controls from the Hispanic population of San Luis Valley, in Colorado. We have used a panel of diallelic genetic markers showing large frequency differences between European and Native American populations to obtain precise admixture estimates. There is no significant difference in Native American contribution between diabetics (38.5%) and controls (37.8%). We discuss this finding in the light of other available data. We also report the distribution of individual admixture proportions in this sample with respect to diabetes and other relevant phenotypes. Finally, we show the results of a study in which we have analyzed the potential association of a number of candidate gene variants and NIDDM in this Hispanic sample. This research has been supported in part by grants to MDS from the NIHNHGRI (HG02154) and NIH-NIDDK (DK53958).

We analyzed admixture in samples of six different African-American populations from South Carolina: Gullah-speaking Sea Islanders in coastal South Carolina, residents of four counties in the 'Low Country' (Berkeley, Charleston, Colleton, and Dorchester), and persons living in the city of Columbia, located in central South Carolina. We used a battery of highly informative autosomal, mtDNA, and Y-chromosome markers. Two of the autosomal markers (FY and AT3) are linked and lie 22 cM apart on chromosome 1. The results of this study indicate, in accordance with previous historical, cultural, and anthropological evidence, a very low level of European admixture in the Gullah Sea Islanders (m = 3.5 [+ or -] 0.9%). The proportion of European admixture is higher in the Low Country (m ranging between 9.9 [+ or -] 1.8% and 14.0 [+ or -] 1.9%), and is highest in Columbia (m = 17.7 [+ or -] 3.1%). A sex-biased European gene flow and a small Native American contribution to the African-American gene pool are also evident in these data. We studied the pattern of pairwise allelic associations between the FY locus and the nine other autosomal markers in our samples. In the combined sample from the Low Country (N = 548), a high level of linkage disequilibrium was observed between the linked markers, FY and AT3. Additionally, significant associations were also detected between FY and 4 of the 8 unlinked markers, suggesting the existence of significant genetic structure in this population. A continuous gene flow model of admixture could explain the observed pattern of genetic structure. A test conditioning on the overall admixture of each individual showed association of ancestry between the two linked markers (FY and AT3), but not between any of the unlinked markers, as theory predicts. Thus, even in the presence of genetic structure due to continuous gene flow or some other factor, it is possible to differentiate associations due to linkage from spurious associations due to genetic structure. Am J Phys Anthropol 114:18-29, 2001. [C] 2001 Wiley-Liss, Inc. KEY WORDS South Carolina, African Americans, admixture, admixture linkage disequilibrium