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Hailu Dadi Melka,전은경,김상욱,James-Bond Han,윤두학,김관석 한국유전체학회 2011 Genomics & informatics Vol.9 No.2
The use of genomic information in genomic selection programs for dairy and beef cattle breeds has become a reality in recent years. In this investigation, we analyzed single-nucleotide polymorphisms (SNPs) for Hanwoo (n=50) and Holstein (n=50) breeds using the Illumina Bovine SNP50 BeadChip to facilitate genomic selection and utilization of the Hanwoo breed in Korea. Analysis of the entire genomes showed different spectra of SNP frequencies for Hanwoo and Holstein cattle. The study revealed a highly significant (p<0.001) difference between Hanwoo and Holstein cattle in minor allele frequency (MAF). The average MAFs were 0.19±0.16 and 0.22±0.16 for Hanwoo and Holstein, respectively. From the total of 52,337 SNPs that were successfully identified,about 72% and 79% were polymorphic in Hanwoos and Holsteins, respectively. Polymorphic and fixed SNPs were not distributed uniformly across the chromosomes within breeds or between the two breeds. The number of fixed SNPs on all chromosomes was higher in Hanwoo cattle, reflecting the genetic uniqueness of the Hanwoo breed. In general, the rate of polymorphisms detected in these two breeds suggests that the SNPs can be used for different applications, such as whole-genome association and comparative genetic studies, and are a helpful tool in developing breed identification genetic markers.
Dadi, Hailu,Kim, Jong-Joo,Yoon, Du-Hak,Kim, Kwan-Suk Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.1
In the present study, we evaluated the informativeness of SNPs genotyped by the Illumina Bovine SNP50K assay in different cattle breeds. To investigate these on a genome-wide scale, we considered 52,678 SNPs spanning the whole autosomal and X chromosomes in cattle. Our study samples consists of six different cattle breeds. Across the breeds approximately 72 and 6% SNPs were found polymorphic and fixed or close to fix in all the breeds, respectively. The variations in the average minor allele frequency (MAF) were significantly different between the breeds studied. The level of average MAF observed in Hanwoo was significantly lower than the other breeds. Hanwoo breed also displayed the lowest number of polymorphic SNPs across all the chromosomes. More importantly, this study indicated that the Bovine SNP50K assay will have reduced power for genome-wide association studies in Hanwoo as compared to other cattle breeds. Overall, the Bovine SNP50K assay described in this study offer a useful genotyping platform for mapping quantitative trait loci (QTLs) in the cattle breeds. The assay data represent a vast and generally untapped resource to assist the investigation of the complex production traits and the development of marker-assisted selection programs.
Dadi, Hailu,Lee, Seung-Hwan,Lee, Seung Soo,Park, Chankyu,Kim, Kwan-Suk Springer-Verlag 2014 Genes & Genomics Vol.36 No.3
In order to facilitate the on-going cattle conservation and improvement programs in Korea, we examined genetic relationships among East Asian cattle, focusing on Korean native cattle, using complete mitochondrial DNA control region sequences. In total, 67 haplotypes were discriminated by 97 variable sites in East Asian cattle. Of the variable sites, 35 represented singleton variable sites and 62 were parsimony informative sites. For Korean cattle, 30 haplotypes were discriminated by 40 variable sites. The variable sites identified in this study correspond to transition or transversion point mutations. Inter-populations genetic distance varied from 0.004 to 0.052 for East Asian cattle populations. The genetic divergence observed between Korean Brown and Jeju Black (0.004) was among the lowest. The Mongolian cattle were slightly divergent from other East Asian cattle populations studied. The network analysis uncovered that Jeju Black and Yunbian samples represented the possible ancestral Haplotype within T3 Bos taurus main lineage. Thus, we hypothesized that the Jeju and Yunbian cattle may represent one of the original native North East Asian cattle in the region.
Reaction mechanism and kinetic modeling of olefin conversion over phosphorus modified ZSM-5 catalyst
Ashenafi Hailu Berta,황호동,Hagos Birhane Asfha,강나영,김기웅,박용기 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.6
Reaction pathways and kinetics of C2-C6 olefins cracking over ZSM-5 catalyst were investigated based onproduct distribution to develop a model. Experimental tests of the catalytic cracking of olefins were performed in thetemperature range of 450-650 oC, space-time of 0.375-3.5min, and partial pressure of 0.08-0.23 atm. For each feed, apossible reaction pathway was identified and used for the model. Based on the identified reactions a lumped kineticmodel was developed using the power-law method. The developed model included direct olefin cracking, oligomerization,and re-cracking of oligomers. Thirteen reversible reactions were considered as major reactions to represent thiscomplex system. For each forward and backward reaction step, apparent activation energy and pre-exponential factorswere estimated. The model predicts the experimental product components with an R2 value of 0.8735-0.9718. Comparisonof experimental result with the developed model showed the developed model predicted the feed product distributionwith accuracy. Sensitivity analysis was done to identify dominant reaction paths for each feed that affected theyield of ethylene and propylene, the main products that needed to be maximized during industrial catalytic cracking.
Bond properties of steel and sand-coated GFRP bars in Alkali activated cement concrete
Biruk Hailu Tekle,Yifei Cui,Amar Khennane 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.75 No.1
The bond performance of glass fibre reinforced polymer (GFRP) bars and that of steel bars embedded in Alkali Activated Cement (AAC) concrete are analysed and compared using pull-out specimens. The bond failure modes, the average bond strength and the free end bond stress-slip curves are used for comparison. Tepfers’ concrete ring model is used to further analyse the splitting failure in ribbed steel bar and GFRP bar specimens. The angle the bond forces make with the bar axis was calculated and used for comparing bond behaviour of ribbed steel bar and GFRP bars in AAC concrete. The results showed that bond failure mode plays a significant role in the comparison of the average bond stress of the specimens at failure. In case of pull-out failure mode, specimens with ribbed steel bars showed a higher bond strength while specimens with GFRP bars showed a higher bond stress in case of splitting failure mode. Comparison of the bond stress-slip curves of ribbed steel bars and GFRP bars depicted that the constant bond stress region at the peak is much smaller in case of GFRP bars than ribbed steel bars indicating a basic bond mechanism difference in GFRP and ribbed steel bars.
Melka, Hailu Dadi,Jeon, Eun-Kyeong,Kim, Sang-Wook,Han, James-Bond,Yoon, Du-Hak,Kim, Kwan-Suk Korea Genome Organization 2011 Genomics & informatics Vol.9 No.2
The use of genomic information in genomic selection programs for dairy and beef cattle breeds has become a reality in recent years. In this investigation, we analyzed single-nucleotide polymorphisms (SNPs) for Hanwoo (n=50) and Holstein (n=50) breeds using the Illumina Bovine SNP50 BeadChip to facilitate genomic selection and utilization of the Hanwoo breed in Korea. Analysis of the entire genomes showed different spectra of SNP frequencies for Hanwoo and Holstein cattle. The study revealed a highly significant (p<0.001) difference between Hanwoo and Holstein cattle in minor allele frequency (MAF). The average MAFs were $0.19{\pm}0.16$ and $0.22{\pm}0.16$ for Hanwoo and Holstein, respectively. From the total of 52,337 SNPs that were successfully identified, about 72% and 79% were polymorphic in Hanwoos and Holsteins, respectively. Polymorphic and fixed SNPs were not distributed uniformly across the chromosomes within breeds or between the two breeds. The number of fixed SNPs on all chromosomes was higher in Hanwoo cattle, reflecting the genetic uniqueness of the Hanwoo breed. In general, the rate of polymorphisms detected in these two breeds suggests that the SNPs can be used for different applications, such as whole-genome association and comparative genetic studies, and are a helpful tool in developing breed identification genetic markers.
Dadi, Hailu,Lee, Seung-Hwan,Jung, Kyoung-Sup,Choi, Jae-Won,Ko, Moon-Suck,Han, Young-Joon,Kim, Jong-Joo,Kim, Kwan-Suk Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.9
The population sizes of three Korean indigenous cattle populations have been drastically reduced over the past decades. In this study, we examined the extent to which reduction in populations influenced genetic diversity, population structure and demographic history using complete mitochondrial DNA (mtDNA) control region sequences. The complete mtDNA control region was sequenced in 56 individuals from Korean Black (KB), Jeju Black (JEB) and Korean Brindle (BRI) cattle populations. We included 27 mtDNA sequences of Korean Brown (BRO) from the GenBank database. Haplotype diversity estimate for the total population was high (0.870) while nucleotide diversity was low (0.004). The KB showed considerably low nucleotide (${\pi}$ = 0.001) and haplotype (h = 0.368) diversities. Analysis of molecular variance revealed a low level of genetic differentiation but this was highly significant (p<0.001) among the cattle populations. Of the total genetic diversity, 7.6% was attributable to among cattle populations diversity and the rest (92.4%) to differences within populations. The mismatch distribution analysis and neutrality tests revealed that KB population was in genetic equilibrium or decline. Indeed, unless an appropriate breeding management practice is developed, inbreeding and genetic drift will further impoverish genetic diversity of these cattle populations. Rational breed development and conservation strategy is needed to safeguard these cattle population.