• Genomics & Informatics
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• v.6 no.2
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• pp.91-94
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• 2008

Single nucleotide polymorphisms (SNPs) are the most abundant form of human genetic variation and are a resource for mapping complex genetic traits. A genome is covered by millions of these markers, and researchers are able to compare which SNPs predominate in people who have a certain disease. The International HapMap Project, launched in October, 2002, motivated us to start the Korean HapMap Project in order to support Korean HapMap infrastructure development and to accelerate the finding of genes that affect health, disease, and individual responses to medications and environmental factors. A Korean SNP and haplotype database system was developed through the Korean HapMap Project to provide Korean researchers with useful data-mining information about disease-associated biomarkers for studies on complex diseases, such as diabetes, cancer, and stroke. Also, we have developed a series of software programs for association studies as well as the comparison and analysis of Korean HapMap data with other populations, such as European, Chinese, Japanese, and African populations. The developed software includes HapMapSNPAnalyzer, SNPflank, HWE Test, FESD, D2GSNP, SNP@Domain, KMSD, KFOD, KFRG, and SNP@WEB. We developed a disease-related SNP retrieval system, in which OMIM, GeneCards, and MeSH information were integrated and analyzed for medical research scientists. The kHapMap Browser system that we developed and integrated provides haplotype retrieval and comparative study tools of human ethnicities for comprehensive disease association studies (http://www.khapmap.org). It is expected that researchers may be able to retrieve useful information from the kHapMap Browser to find useful biomarkers and genes in complex disease association studies and use these biomarkers and genes to study and develop new drugs for personalized medicine.

• Proceedings of the KAIS Fall Conference
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• 2007.11a
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• pp.305-307
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• 2007

Struvite(MAP) 및 hydroxyapatite(HAP) 결정화로 질소 및 인을 제거하기 위한 최적조건을 평가하기 위한 실험을 실시하였으며, $Mg^{2+}$, $NH_4^+$, $PO_4^{3-}$ 및 $Ca^{2+}$용액을 이용하여 인공폐수를 조제하였으며 각 이온의 몰비 조건을 1:1:1에서 실험을 수행하였다. $Ca^{2+}$ 및 $PO_4^{3-}$를 이용한 HAP 결정화는 알칼리조건의 pH 범위에서는 pH에 큰영향을 받지 않고 HAP가 형성되었으며, MAP 및 HAP 동시 결정화를 위한 실험에서는 pH가 증가하면서 $NH_4^+$, $PO_4^{3-}$ 제거효율은 감소하며 $Ca^{2+}$ 및 $Mg^{2+}$는 모든 pH에서 99% 이상 제거되었다. 폐수중에 $Ca^{2+}$이 포함되어 있다면 pH 9.5에서 $Mg^{2+}:NH_4^+:PO_4^{3-}:Ca^{2+}$는 1.2:1.0:1.2:2.0의 몰비로 존재했을 때 MAP 및 HAP 생성 최적조건인 것으로 나타났다. 그러나 pH가 10이상이 되면 부반응으로 인해 각종 무정형 결정체가 생성되므로 MAP 생성을 위해서는 pH 9.5로 운영을 하는 것이 가장 바람직하다.

• Journal of Korean Society on Water Environment
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• v.32 no.4
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• pp.343-348
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• 2016

A chemical sequencing batch reactor was operated to test the feasibility of nutrient recovery from a biological livestock wastewater treatment plant. Both phosphate and ammonia could be successfully recovered as magnesium ammonium phosphate (MAP) crystals. The contents of TP and TN in the recovered MAP crystals were 26.2% and 4.0%, respectively. Zn, Cr and Ti were identified in the crystals, but the contents remained below the Korean standard for an organic fertilizer. Chemical analyses confirmed that the MAP crystals could be useful phosphate fertilizers. On the other hand, the results of physical analyses using an X-ray diffractometer and an energy dispersive X-ray spectrometer strongly suggested that crystalline materials like magnesium potassium phosphate (KMP) and hydroxyapatite (HAP) were also formed during the MAP crystallization, depending on the availability of K⁺ and Ca²⁺.

• Genomics & Informatics
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• v.12 no.1
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• pp.35-41
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• 2014

Single-nucleotide polymorphisms (SNPs) have been emerging out of the efforts to research human diseases and ethnic disparities. A semantic network is needed for in-depth understanding of the impacts of SNPs, because phenotypes are modulated by complex networks, including biochemical and physiological pathways. We identified ethnicity-specific SNPs by eliminating overlapped SNPs from HapMap samples, and the ethnicity-specific SNPs were mapped to the UCSC RefGene lists. Ethnicity-specific genes were identified as follows: 22 genes in the USA (CEU) individuals, 25 genes in the Japanese (JPT) individuals, and 332 genes in the African (YRI) individuals. To analyze the biologically functional implications for ethnicity-specific SNPs, we focused on constructing a semantic network model. Entities for the network represented by "Gene," "Pathway," "Disease," "Chemical," "Drug," "ClinicalTrials," "SNP," and relationships between entity-entity were obtained through curation. Our semantic modeling for ethnicity-specific SNPs showed interesting results in the three categories, including three diseases ("AIDS-associated nephropathy," "Hypertension," and "Pelvic infection"), one drug ("Methylphenidate"), and five pathways ("Hemostasis," "Systemic lupus erythematosus," "Prostate cancer," "Hepatitis C virus," and "Rheumatoid arthritis"). We found ethnicity-specific genes using the semantic modeling, and the majority of our findings was consistent with the previous studies - that an understanding of genetic variability explained ethnicity-specific disparities.

• Genomics & Informatics
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• v.5 no.4
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• pp.188-193
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• 2007

The Functional Element SNPs Database (FESD) categorizes functional elements in human genic regions and provides a set of single nucleotide polymorphisms (SNPs) located within each area. Users may select a set of SNPs in specific functional elements with haplotype information and obtain flanking sequences for genotyping. Our previous version of FESD has been improved in several ways. We regenerated all the data in FESD II from recently updated source data such as HapMap, UCSC GoldenPath, dbSNP, OMIM, and $TRANSFAC^{(R)}$. Users can obtain information about tagSNPs and simulate LD blocks for each gene from four ethnicities in the HapMap project on the fly. FESD II employs a Java/JSP web interface for better platform portability and higher speed than PHP in the previous version. As a result, FESD II provides its users with more powerful information about functional element SNPs of human ethnicities.

• Genomics & Informatics
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• v.6 no.2
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• pp.57-63
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• 2008

The Korean HapMap Project has been carried out for the last 5 years since it started in June, 2003. The project generated data for a sum of 1,764,000 Korean SNPs and formally registered the data to the dbSNP of NCBI (The dbSNP website. 2008). We have developed a series of software programs for association studies as well as for the comparison and analysis of Korean HapMap data with four other populations (CEPH, Yoruba, Han Chinese, and Japanese populations). The KHapmap Browser was developed and integrated to provide haplotype retrieval and comparative study tools of human ethnicities for comprehensive disease association studies (http://www.khapmap.org). On that basis, GBrowse was adopted in the KHapmap Browser for inherent Korean genetic data, and a provision of extended services was pledged with the distributed sequence annotation system (DAS). The dynamic linking service of the KHapmap Browser to other tools in our intranetwork environment provides many enhanced functions over GBrowse without DAS. KHapmap Browser is expected to be an invaluable tool for the study of Korean and international Hapmap data.

• Genomics & Informatics
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• v.7 no.2
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• pp.136-140
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• 2009

Genome-wide association (GWA) studies may benefit from the inclusion of imputed SNPs into their dataset. Due to its predictive nature, the imputation process is typically not perfect. Thus, it would be desirable to develop a scheme for filtering out the imputed SNPs by maximizing the concordance with the observed genotypes. We report such a scheme, which is based on the combination of several parameters that are calculated by PLINK, a popular GWA analysis software program. We imputed the genotypes of 8,842 Korean individuals, based on approximately 2 million SNP genotypes of the CHB＋JPT panel in the International HapMap Project Phase II data, complementing the 352k SNPs in the original Affymetrix 5.0 dataset. A total of 333,418 SNPs were found in both datasets, with a median concordance rate of 98.7%. The concordance rates were calculated at different ranges of parameters, such as the number of proxy SNPs (NPRX), the fraction of successfully imputed individuals (IMPUTED), and the information content (INFO). The poor concordance that was observed at the lower values of the parameters allowed us to develop an optimal combination of the cutoffs (IMPUTED${\geq}$0.9 and INFO${\geq}$0.9). A total of 1,026,596 SNPs passed the cutoff, of which 94,364 were found in both datasets and had 99.4% median concordance. This study illustrates a conservative scheme for filtering imputed SNPs that would be useful in GWA studies.

• The Korea Genome Conference
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• 2004.07a
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• pp.37.1-37.1
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• 2004

• Genomics & Informatics
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• v.6 no.3
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• pp.130-135
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• 2008

The haplotypes of a 200 kb region in the human chromosome X terminal band (q28) were analyzed using the International HapMap Project Phasell data, which had been collected for three analysis panels (YRI, CEU, and CHB＋JPT). When multiple linkage disequilibrium blocks were encountered for a panel, the neighboring haplotypes that had crossover rate of 5% or more in the panel were combined to generate 'haploid' configurations. This resulted in 8, 7, and 5 'haploid' configurations for the panels of YRI, CEU, and CHB＋JPT, respectively. The multiple sequence alignment of these 'haploids' was used for the calculation of allele-sharing distances and the subsequent principal coordinate analysis. Two 'haploids' in CEU and CHB＋JPT were hypothesized as 'parental' in light of the observations that the successive recombinants of these haploids can model two other haploids in CEU and CHB＋JPT, and that their configurations were consistent with those in YRI. This study demonstrates the utility of haplotype phylogeny in understanding population evolution.

• Genomics & Informatics
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• v.6 no.1
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• pp.18-28
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• 2008

Single nucleotide polymorphisms (SNPs) are the most abundant forms of human genetic variations and resources for mapping complex genetic traits and disease association studies. We have constructed a linkage disequilibrium (LD) map of chromosome 22 in Korean samples and compared it with those of other populations, including Yorubans in Ibadan, Nigeria (YRI), Centre d'Etude du Polymorphisme Humain (CEPH) reference families (CEU), Japanese in Tokyo (JPT) and Han Chinese in Beijing (CHB) in the HapMap database. We genotyped 4681 of 111,448 publicly available SNPs in 90 unrelated Koreans. Among genotyped SNPs, 4167 were polymorphic. Three hundred and five LD blocks were constructed to make up 18.6% (6.4 of 34.5 Mb) of chromosome 22 with 757 tagSNPs and 815 haplotypes (frequency $\geq$ 5.0%). Of 3430 common SNPs genotyped in all five populations, 514 were monomorphic in Koreans. The CHB + JPT samples have more than a 72% overlap with the monomorphic SNPs in Koreans, while the CEU + YRI samples have less than a 38% overlap. The patterns of hot spots and LD blocks were dispersed throughout chromosome 22, with some common blocks among populations, highly concordant between the three Asian samples. Analysis of the distribution of chimpanzee-derived allele frequency (DAF), a measure of genetic differentiation, Fst levels, and allele frequency difference (AFD) among Koreans and the HapMap samples showed a strong correlation between the Asians, while the CEU and YRI samples showed a very weak correlation with Korean samples. Relative distance as a quantitative measurement based upon DAF, Fst, and AFD indicated that all three Asian samples are very proximate, while CEU and YRI are significantly remote from the Asian samples. Comparative genome-wide LD studies provide useful information on the association studies of complex diseases.