| 1 |
CASE-BASED TEACHING PERFORMANCE EVALUATION SYSTEM AND AN IMPROVED ANALYTIC HIERARCHY PROCESS MODEL USING LINGUISTIC VARIABLES ...
|
|
|
|
BASE
|
|
Show details
|
|
|
| 2 |
CASE-BASED TEACHING PERFORMANCE EVALUATION SYSTEM AND AN IMPROVED ANALYTIC HIERARCHY PROCESS MODEL USING LINGUISTIC VARIABLES ...
|
|
|
|
BASE
|
|
Show details
|
|
|
| 3 |
Unsupervised Event Extraction from News and Twitter ; IDEAL Computational Linguistics Prototype
|
|
|
|
BASE
|
|
Show details
|
|
|
| 4 |
Classroom-based Cognitive Diagnostic Model For a Teacher-made Fraction- Decimal Test
|
|
|
|
In: http://www.ifets.info/journals/16_3/26.pdf (2012)
|
|
BASE
|
|
Show details
|
|
|
| 5 |
A Detection and Annotation System for Internet New Words in Taiwan
|
|
|
|
In: http://www.wseas.us/e-library/conferences/2005miami/papers/501-355.pdf
|
|
BASE
|
|
Show details
|
|
|
| 6 |
Increasing Expressiveness of Composite Events Using Parameter Contexts
|
|
|
|
In: http://www.cs.colostate.edu/~iray/research/adbis08.pdf
|
|
BASE
|
|
Show details
|
|
|
| 7 |
Sciences of the USA 1418 -1421 ͉ PNAS
|
|
|
|
In: http://www.picb.ac.cn/picb-dynamic/admin/pic/JinLi2006-Linkage-disequilibrium%20sharing%20and%20haplotype-tagged%20snp%20portability%20between%20populations.pdf
|
|
Abstract:
The discovery of the block-like structure of linkage disequilibrium (LD) in human populations holds the promise of delineating the etiology of common diseases. However, understanding the magnitude, mechanism, and utility of between-population LD sharing is critical for future genome-wide association studies. In this study, substantial LD sharing between six non-African populations was observed, although much less between African-American and non-African, based on 20,000 SNPs of chromosome 21. We also demonstrated the respective roles of recombination and demographic events in shaping LD sharing. Furthermore, we showed that the haplotype-tagged SNPs chosen from one population are portable to the others in East Asia. Therefore, we concluded that the magnitude of LD sharing between human populations justifies the use of representative populations for selecting haplotypetagged SNPs in genome-wide association studies of complex diseases. bottleneck ͉ genetic distance ͉ association study ͉ common disease ͉ genetic variant C omprehensive testing of the association between genetic variations in the human genome and common diseases holds the promise of delineating the genetic architecture of these diseases (1-5). Substantial sharing of the boundaries and specific haplotypes of linkage disequilibrium (LD) blocks between populations was observed (6). However, variations of haplotype and LD across populations were also reported, raising concerns on its practical hindrance for genomewide testing of association (7-9). Conflicting observations on the magnitude of LD sharing between human populations, therefore, call for a careful examination of the following three questions, which are fundamental in developing strategies for genomewide testing of association. First, measurement of LD sharing between populations should be made independent of the definition of LD blocks, which introduce inconsistent block boundaries (10). Second, the mechanisms that shape LD sharing between populations are yet to be fully explored although the roles of recombination hotspots and demographic events have been implicated To address the aforementioned questions, we typed Ͼ20,000 SNPs on chromosome 21 in seven populations: three representative continental populations [African-American (AFR), European (EUR), and Han Chinese (HAN)] and four other major East Asian (EA) populations. This design allows a close examination of LD sharing between continental groups as well as those within East Asia. In this report, we measured the LD sharing between populations independent of the definition of LD block; and we showed that bottleneck events play a critical role in shaping the LD sharing between Africans and nonAfricans, but much less so between non-Africans. An important question for applying HapMap results to disease studies is how tagSNPs selected from a HapMap population will be ported to disease studies performed in other populations. In this study, we showed that tagSNPs selected from representative continental populations are indeed portable to the others in the same continent for association studies, at least in East Asia, with reasonable efficiency. In addition, we proposed a simple guideline that allows a quick evaluation of the portability of tagSNPs between populations by typing a small number of SNPs. Results Overall 26,112 SNPs were selected and typed in this study, and the data from 19,060 SNPs passed the quality control criteria and were used for further analyses. The SNPs and quality control criteria for SNP selection are described in Materials and Methods. Seven world populations, including EUR, AFR, and five EA populations, were studied. The five EA populations, i.e., HAN, Miao (HMJ), Zhuang (CCY), Wa (WBM), and Uighur (UIG), represent five major linguistic families spoken in East Asia. Preservation of LD between populations, i.e., LD sharing (S, or S AB when the population A was given as reference), is measured by the proportion of SNP pairs in LD in one population (population A or the reference) that are also in LD in another (population B). In this study, LD sharing was estimated without invoking the inference of haplotype blocks; therefore, the measure is independent of the definition of haplotype blocks. LD between two loci was measured in r 2 (16). Detail for the measure of LD sharing is described in Materials and Methods. LD sharing between EAs ranges from 63-74% for r 2 Ն 0.1 and 70-84% for r 2 Ն 0.5 (see
|
|
URL: http://www.picb.ac.cn/picb-dynamic/admin/pic/JinLi2006-Linkage-disequilibrium%20sharing%20and%20haplotype-tagged%20snp%20portability%20between%20populations.pdf
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1054.6191
|
|
BASE
|
|
Hide details
|
|
|
|
|
