• Title/Summary/Keyword: Marker Spacing

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Evaluation of Cofactor Markers for Controlling Genetic Background Noise in QTL Mapping

  • Lee, Chaeyoung;Wu, Xiaolin
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.4
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    • pp.473-480
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    • 2003
  • In order to control the genetic background noise in QTL mapping, cofactor markers were incorporated in single marker analysis (SMACO) and interval mapping (CIM). A simulation was performed to see how effective the cofactors were by the number of QTL, the number and the type of markers, and the marker spacing. The results of QTL mapping for the simulated data showed that the use of cofactors was slightly effective when detecting a single QTL. On the other hand, a considerable improvement was observed when dealing with more than one QTL. Genetic background noise was efficiently absorbed with linked markers rather than unlinked markers. Furthermore, the efficiency was different in QTL mapping depending on the type of linked markers. Well-chosen markers in both SMACO and CIM made the range of linkage position for a significant QTL narrow and the estimates of QTL effects accurate. Generally, 3 to 5 cofactors offered accurate results. Over-fitting was a problem with many regressor variables when the heritability was small. Various marker spacing from 4 to 20 cM did not change greatly the detection of multiple QTLs, but they were less efficient when the marker spacing exceeded 30 cM. Likelihood ratio increased with a large heritability, and the threshold heritability for QTL detection was between 0.30 and 0.05.

An AFLP-based Linkage Map of Japanese Red Pine (Pinus densiflora) Using Haploid DNA Samples of Megagametophytes from a Single Maternal Tree

  • Kim, Yong-Yul;Choi, Hyung-Soon;Kang, Bum-Yong
    • Molecules and Cells
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    • v.20 no.2
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    • pp.201-209
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    • 2005
  • We have constructed an AFLP-based linkage map of Japanese red pine (Pinus densiflora Siebold et Zucc.) using haploid DNA samples of 96 megagametophytes from a single maternal tree, selection clone Kyungbuk 4. Twenty-eight primer pairs generated a total of 5,780 AFLP fragments. Five hundreds and thirteen fragments were verified as genetic markers with two alleles by their Mendelian segregation. At the linkage criteria LOD 4.0 and maximum recombination fraction 0.25(${\theta}$), a total of 152 markers constituted 25 framework maps for 19 major linkage groups. The maps spanned a total length of 2,341 cM with an average framework marker spacing of 18.4 cM. The estimated genome size was 2,662 cM. With an assumption of equal marker density, 82.2% of the estimated genome would be within 10 cM of one of the 230 linked markers, and 68.1% would be within 10 cM of one of the 152 framework markers. We evaluated map completeness in terms of LOD value, marker density, genome length, and map coverage. The resulting map will provide crucial information for future genomic studies of the Japanese red pine, in particular for QTL mapping of economically important breeding target traits.

Study on High Accurate Schemes for Simulation of Free-surface Flow (자유표면 유동 시뮬레이션을 위한 고정확도 수치도식의 검토)

  • Park, Jong-Chun;Lee, Byoung-Hyuk;Kim, Jeung-Hu
    • Journal of Ocean Engineering and Technology
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    • v.20 no.4 s.71
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    • pp.31-36
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    • 2006
  • Numerical schemes for spacing and time are tested to accurately simulate the wave propagation. The tested numerical schemesinclude 2nd-order central differencing, l-order upwind scheme, 2nd-order Leith scheme, 3rd-order MUSCLE, QUICK and QUICKEST schemes in spacing and the Euler and 4th-order Runge-Kutta(R-K) schemes in time. It is seen that more accurate results are expected when the higher-order schemes, especially the schemes combined with a TVD control limiter, are used for solving the wave equation. The 3rd-order upwind scheme with limiter and the 4th-order R-K scheme in tim£ are finally applied to the wave-making simulation in a digital wave tank.

Detection of Sub-Breaking Waves around a Blunt Bow (비대선수 주위의 Sub-Breaking Wave 탐지기법)

  • Myung-Soo Shin;Young-Gill Lee;Eun-Chan Kim;Seung-Il Yang
    • Journal of the Society of Naval Architects of Korea
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    • v.29 no.3
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    • pp.117-124
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    • 1992
  • Waves around a practical hull form and a series 60 model are computed by rectangular variable spacing and staggered flesh systems based on MAC(Marker and Cell) method. As a governing equation, the Euler equation is adopted. The comparison indicates that the computed waves are in good agreement with the measured results and that the MAC method is useful. On the other hand, a critical condition for the appearance of sub-breaking waves derived from the in viscid instability analysis is applied to the calculated flow field around a blunt bow. It is confirmed that the derived condition detects well the appearance of sub-breaking waves.

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Localization of Quantitative Trait Loci for Bone Mineral Density on Chromosome 13 in the Mongolian Population

  • Seo, Soo-Hyun;Lim, Hae-Jeng;Ahn, Se-Jin;Lee, Joseph;Kim, Jong-Il
    • Genomics & Informatics
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    • v.7 no.3
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    • pp.152-158
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    • 2009
  • Although the genetic basis for bone mineral density (BMD) has been studied by many groups so far, genes responsible for this complex trait has not been completely revealed. In order to localize quantitative trait loci (QTLs) for BMD variation in Asian population, the study was designed using a group of Mongolian population, a genetically closed population with a homogeneous lifestyle. BMD was measured at the left and right wrists and ankles using DEXA in 1,082 participants from 142 families. Genotyping of 13 polymorphic microsatellite markers on chromosome 13 (average spacing 8-9 cM) and two-point and multipoint linkage analysis were performed. In two-point linkage analysis, we identified two markers, D13S175 (6.03 cM) and D13S265 (68.73 cM) that had LOD scores greater than 1 for left ankle (LOD=2.09, LOD=1.49, respectively). We also found a marker D13S175 (6.03 cM) with a high LOD for left wrist (LOD=1.49) and the markers D13S265 (68.73 cM) and D13S217 (17.21 cM) for the right wrist (LOD= 1.82, LOD= 1.62, respectively). Among these significant marker regions, only two regions at 17 cM (13p11) and 65 cM (13q21) for the right wrist overlapped with major QTLs reported in following multipoint linkage analysis (LOD= 1.7549, LOD=1.4462, respectively). This study provides the possible evidence of the presence of QTLs affecting right wrist BMD in Mongolian populations on 13p11 and 13q21. Modest evidence was also found for genes affecting left ankle and left wrist BMD on 13p13.

Case Study on the Writing of the Papers of Journal of the Korean Association for Science Education (한국과학교육학회지 논문의 글쓰기 사례 연구)

  • Han, JaeYoung
    • Journal of The Korean Association For Science Education
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    • v.35 no.4
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    • pp.649-663
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    • 2015
  • This study investigated the current state of writing in research papers of science education with focus on the translationese and basic Korean grammar, and found a way of improving the Korean language. The science education research have characteristics of both social science and natural science, and of having more quantitative than qualitative research, which could influence the writing of the research paper. The translationese means the conventional expression originated from foreign language other than Korean. The basic Korean grammar includes 'agreement,' 'spelling, word spacing, punctuation mark,' 'causative suffix,' 'use of English or loanword,' and the translationese is divided in 'English,' 'Japanese,' and 'English and Japanese.' The sentences in nine research papers in the 'Journal of the Korean Association for Science Education' were analyzed, and the problematic sentences were discussed and provided with alternatives. The cases with high frequency include '-jeok,' 'use of English,' 'expression of the plural,' 'passive voice of the verb with -hada,' '-go inneun,' '-eul tonghayeo,' '-e daehayeo,' 'gajida,' 'genitive case marker -eui,' 'passive voice with subject of thing,' and 'causative suffix, -sikida.' Based on the results, the characteristics of writing of science education research papers were described as 'writing of quantitative research,' 'objective writing of academic research,' and 'writing of research of foreign origin.' In order to improve the writing of research paper of science education, the science education researcher should pay attention to basic Korean grammar and the translationese, and be familiar with the concrete examples of problematic cases. The results of this study could be used in the education of writing and grammar of Korean language.