• Title/Summary/Keyword: Association mapping

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QTL Identification Using Combined Linkage and Linkage Disequilibrium Mapping for Milk Production Traits on BTA6 in Chinese Holstein Population

  • Hu, F.;Liu, J.F.;Zeng, Z.B.;Ding, X.D.;Yin, C.C.;Gong, Y.Z.;Zhang, Q.
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.10
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    • pp.1261-1267
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    • 2010
  • Milk production traits are important economic traits for dairy cattle. The aim of the present study was to refine the position of previously detected quantitative trait loci (QTL) on bovine chromosome 6 affecting milk production traits in Chinese Holstein dairy cattle. A daughter design with 918 daughters from 8 elite sire families and 14 markers spanning the previously identified QTL region were used in the analysis. We employed a combined linkage and linkage disequilibrium analysis (LDLA) approach with two options for calculating the IBD probabilities, one was based on haplotypes of all 14 markers (named Method 1) and the other based on haplotypes with sliding windows of 5 markers (named Method 2). For milk fat yield, the two methods revealed a highly significant QTL located within a 6.5 cM interval (Method 1) and a 4.0 cM interval (Method 2), respectively. For milk protein yield, a highly significant QTL was detected within a 3.0 cM interval (Method 1) or a 2.5 cM interval (Method 2). These results confirmed the findings of our previous study and other studies, and greatly narrowed down the QTL positions.

Characterization of microsatellite markers covering chromosome 1 in the Korean and Japanese populations (한국인과 일본인에서 1번 염색체에 부착되는 microsatellite marker의 특징)

  • Lee, You-Jin;Park, Soo-Byung
    • The korean journal of orthodontics
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    • v.34 no.6 s.107
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    • pp.537-543
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    • 2004
  • Microsatellit markers are considered to be very promising genetic markers for genetic linkage analysis. The majority of the markers are as informative as in Caucasians but there are significant ethnic differences in the genetic variations. In order to investigate the genetic variations in the Korean and Japanese populations and their ethnic differences, 51 microsatellite marker loci spanning the whole human chromosome 1 were arranged from a commercially available set (ABI PRISM Linkage Mapping Set-HD5, Applied Biosystems, Foster City, CA, USA), and then determined the allelic frequencies and heterozygosities for these marker loci in the 90 unrelated Korean subjects and 90 unrelated Japanese subjects. Of all 51 markers tested, significant differences were observed when microsatellite allele frequency pattern of Korean was compared with those of Caucasian, while this pattern was highly similar between Korean and Japanese populations. Our data indicate that an extensive verification of public microsatellite markers in a particular population study should be undertaken prior to their linkage studies. Moreover, this information should facilitate genetic linkage studies of various hereditary diseases, especially in the Koreans and Japanese.

SIMULATION OF REGIONAL DAILY FLOW AT UNGAGED SITES USING INTEGRATED GIS-SPATIAL INTERPOLATION (GIS-SI) TECHNIQUE

  • Lee, Ju-Young;Krishinamursh, Ganeshi
    • Water Engineering Research
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    • v.6 no.2
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    • pp.39-48
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    • 2005
  • The Brazos River is one of the longest rivers contained entirely in the state of Texas, flowing over 700 miles from northwest Texas to the Gulf of Mexico. Today, the Brazos River Authority and Texas Commission on Environmental Quality interest in drought protection plan, waterpower project, and allowing the appropriation of water system-wide and water right within the Brazos River Basin to meet water needs of customers like farmers and local civilians in the future. Especially, this purpose of this paper primarily intended to provide the data for the engineering guidelines and make easily geological mapping tool. In the Brazos River basin, many stream-flow gage station sites are not working, and they can not provide stream-flow data sets enough for development of the Probable Maximum Flood (PMF) for use in the evaluation of proposed and existing dams and other impounding structures. Integrated GIS-Spatial Interpolation (GIS-SI) tool are composed of two parts; (1) extended GIS technique (new making interface for hydrological regionalization parameters plus classical GIS mapping skills), (2) Spatial Interpolation technique using weighting factors from kriging method. They are obtained from the relationship among location and elevation of geological watershed and existing stream-flow datasets. GIS-SI technique is easily used to compute parameters which get drainage areas, mean daily/monthly/annual precipitation, and weighted values. Also, they are independent variables of multiple linear regressions for simulation at un gaged stream-flow sites. In this study, GIS-SI technique is applied to the Brazos river basin in Texas. By assuming the ungaged flow at the sites of Palo Pinto, Bryan and Needville, the simulated daily/monthly/annual time series are compared with observed time series. The simulated daily/monthly/annual time series are highly correlated with and well fitted to the observed times series.

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Analysis of allele-specific expression using RNA-seq of the Korean native pig and Landrace reciprocal cross

  • Ahn, Byeongyong;Choi, Min-Kyeung;Yum, Joori;Cho, In-Cheol;Kim, Jin-Hoi;Park, Chankyu
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.12
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    • pp.1816-1825
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    • 2019
  • Objective: We tried to analyze allele-specific expression in the pig neocortex using bioinformatic analysis of high-throughput sequencing results from the parental genomes and offspring transcriptomes from reciprocal crosses between Korean Native and Landrace pigs. Methods: We carried out sequencing of parental genomes and offspring transcriptomes using next generation sequencing. We subsequently carried out genome scale identification of single nucleotide polymorphisms (SNPs) in two different ways using either individual genome mapping or joint genome mapping of the same breed parents that were used for the reciprocal crosses. Using parent-specific SNPs, allele-specifically expressed genes were analyzed. Results: Because of the low genome coverage (${\sim}4{\times}$) of the sequencing results, most SNPs were non-informative for parental lineage determination of the expressed alleles in the offspring and were thus excluded from our analysis. Consequently, 436 SNPs covering 336 genes were applicable to measure the imbalanced expression of paternal alleles in the offspring. By calculating the read ratios of parental alleles in the offspring, we identified seven genes showing allele-biased expression (p<0.05) including three previously reported and four newly identified genes in this study. Conclusion: The newly identified allele-specifically expressing genes in the neocortex of pigs should contribute to improving our knowledge on genomic imprinting in pigs. To our knowledge, this is the first study of allelic imbalance using high throughput analysis of both parental genomes and offspring transcriptomes of the reciprocal cross in outbred animals. Our study also showed the effect of the number of informative animals on the genome level investigation of allele-specific expression using RNA-seq analysis in livestock species.

Genetic Diversity Analysis of Proso millet (Panicum miliaceum) Germplasm Using EST-SSR Markers

  • Lee, Myung-Chul;Choi, Yu-Mi;Yun, Hyemyeong;Shin, Myoung-Jae;Lee, Sukyeung;Oh, Sejong
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2019.10a
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    • pp.43-43
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    • 2019
  • The collection, evaluation and conservation of crop germplasm have been treated as one of the basics to breeding program. An understanding of genetic relationships among germplasm resources is vital for future breeding process like yield, quality, and resistance. In the present study, EST-SSR markers were employed to assess the polymorphism and genetic diversity of 192 accessions of Proso millet preserved in the National Agrobiodiversity Center of RDA. We evaluated the efficiency of EST-SSR markers developed for proso millet species. A total of 98 alleles were detected with an average allele number of 4.5 per locus among 192 proso millet millet accessions using 22 EST-SSR markers. The averaged values of gene diversity ($H_E$) and polymorphism information content (PIC) for each EST-SSR marker were 0.362 and 0.404 within populations, respectively. Our results showed the moderate level of the molecular diversity among the proso millet accessions from diverse countries. A phylogenetic tree revealed three major groups of accessions that did not correspond with geographical distribution patterns with a few exceptions. The less correlation between the clusters and their geographic location might be considered due to their type difference. Our study provided a better understanding of genetic relationships among various germplasm collections, and it could contribute to more efficient utilization of valuable genetic resources. The EST-SSR markers developed here will serve as a valuable resource for genetic studies, like linkage mapping, diversity analysis, quantitative trait locus/association mapping, and molecular breeding.

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Effects of quantitative trait loci determining testicular weight in DDD/Sgn inbred mice are strongly influenced by circulating testosterone levels

  • Suto, Jun-ichi;Kojima, Misaki
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.12
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    • pp.1826-1835
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    • 2019
  • Objective: Testicular growth and development are strongly influenced by androgen. Although both testis weight and plasma testosterone level are inherited traits, the interrelationship between them is not fully established. Males of DDD/Sgn (DDD) mice are known to have extremely heavy testes and very high plasma testosterone level among inbred mouse strains. We dissected the genetic basis of testis weight and analyzed the potential influence of plasma testosterone level in DDD mice. Methods: Quantitative trait loci (QTL) mapping of testis weight was performed with or without considering the influence of plasma testosterone level in reciprocal $F_2$ intercross populations between DDD and C57BL/6J (B6) mice, thereby assessing the influence of testosterone on the effect of testis weight QTL. Candidate genes for testis weight QTL were investigated by next-generation sequencing analysis. Results: Four significant QTL were identified on chromosomes 1, 8, 14, and 17. The DDDderived allele was associated with increased testis weight. The $F_2$ mice were then divided into two groups according to the plasma testosterone level ($F_2$ mice with relatively "low" and "high" testosterone levels), and QTL scans were again performed. Although QTL on chromosome 1 was shared in both $F_2$ mice, QTL on chromosomes 8 and 17 were identified specifically in $F_2$ mice with relatively high testosterone levels. By whole-exome sequencing analysis, we identified one DDD-specific missense mutation Pro29Ser in alpha tubulin acetyltransferase 1 (Atat1). Conclusion: Most of the testis weight QTL expressed stronger phenotypic effect when they were placed on circumstance with high testosterone level. High testosterone influenced the QTL by enhancing the effect of DDD-derived allele and diminishing the effects of B6-derived allele. Since Pro29Ser was not identified in other inbred mouse strains, and since Pro29 in Atat1 has been strongly conserved among mammalian species, Atat1 is a plausible candidate for testis weight QTL on chromosome 17.

The acculturation experience of Chinese international students in South Korea: Coping and perceived changes in the cultural transition (중국 유학생의 문화적응 경험: 대처와 지각 변화를 중심으로)

  • Lee, Yu Young;Kim, Hanjoo;Nam, Suk Kyung;Jin, Ling;Yang, Eunjoo
    • Korean Journal of School Psychology
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    • v.8 no.3
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    • pp.379-403
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    • 2011
  • This study examined coping strategies and perceived changes of the Chinese international students in South Korea. A total of 56 Chinese students participated and data was analyzed using the concept mapping method. The results showed that Chinese international students adopted developing language proficiency and using social networks as important coping strategies. They also perceived a wide range of changes including changes in the cultural and personal self. However, the perception of these coping strategies and changes differed by the length of stay. Chinese international students who stayed longer reported using specific coping strategies for mood regulation, which was distinctive from the coping strategies used by students who stayed for a shorter period of time. Students who stayed longer perceived negative changes as well as positive changes, while students who stayed for a shorter period reported predominantly positive changes. The findings indicate that university staff needs to understand and sensitively respond to the distinctive experiences of Chinese international students which vary across time.

Cortical Iron Accumulation as an Imaging Marker for Neurodegeneration in Clinical Cognitive Impairment Spectrum: A Quantitative Susceptibility Mapping Study

  • Hyeong Woo Kim;Subin Lee;Jin Ho Yang;Yeonsil Moon;Jongho Lee;Won-Jin Moon
    • Korean Journal of Radiology
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    • v.24 no.11
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    • pp.1131-1141
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    • 2023
  • Objective: Cortical iron deposition has recently been shown to occur in Alzheimer's disease (AD). In this study, we aimed to evaluate how cortical gray matter iron, measured using quantitative susceptibility mapping (QSM), differs in the clinical cognitive impairment spectrum. Materials and Methods: This retrospective study evaluated 73 participants (mean age ± standard deviation, 66.7 ± 7.6 years; 52 females and 21 males) with normal cognition (NC), 158 patients with mild cognitive impairment (MCI), and 48 patients with AD dementia. The participants underwent brain magnetic resonance imaging using a three-dimensional multi-dynamic multi-echo sequence on a 3-T scanner. We employed a deep neural network (QSMnet+) and used automatic segmentation software based on FreeSurfer v6.0 to extract anatomical labels and volumes of interest in the cortex. We used analysis of covariance to investigate the differences in susceptibility among the clinical diagnostic groups in each brain region. Multivariable linear regression analysis was performed to study the association between susceptibility values and cognitive scores including the Mini-Mental State Examination (MMSE). Results: Among the three groups, the frontal (P < 0.001), temporal (P = 0.004), parietal (P = 0.001), occipital (P < 0.001), and cingulate cortices (P < 0.001) showed a higher mean susceptibility in patients with MCI and AD than in NC subjects. In the combined MCI and AD group, the mean susceptibility in the cingulate cortex (β = -216.21, P = 0.019) and insular cortex (β = -276.65, P = 0.001) were significant independent predictors of MMSE scores after correcting for age, sex, education, regional volume, and APOE4 carrier status. Conclusion: Iron deposition in the cortex, as measured by QSMnet+, was higher in patients with AD and MCI than in NC participants. Iron deposition in the cingulate and insular cortices may be an early imaging marker of cognitive impairment related neurodegeneration.

Effect of LI4-LI11 Transcutaneous Electrical Nerve Stimulation on Regional Cerebral Blood Flow in Healthy Human Using SPECT and Statistical Parametric Mapping (뇌 SPECT와 SPM을 이용한 합곡-곡지 TENS 치료의 뇌혈류에 대한 효과)

  • Jeong, Dong-Won;Kim, Young-Suk;Park, Seong-Uk;Jung, Woo-Sang;Park, Jung-Mi;Ko, Chang-Nam;Cho, Ki-Ho;Bae, Hyung-Sup;Kim, Deok-Yoon;Moon, Sang-Kwan
    • The Journal of Korean Medicine
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    • v.29 no.4
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    • pp.205-212
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    • 2008
  • Background and purpose: So far it was reported that acupuncture increased cerebral blood supply and stimulated the functional activity of brain nerve cells. A previous study demonstrated a correlation between LI4-11 electro-acupuncture (EA) and rCBF increase in frontal lobe. However, there remained a need to study further using various controls in acupuncture research. Transcutaneous electrical nerve stimulation (TENS) has been used as a non-invasive control in acupuncture study. This study was to evaluate the effect of LI4-LI11 TENS on regional cerebral blood flow (rCBF) in normal volunteers using single photon emission computed tomography (SPECT) and statistical parametric mapping (SPM). Methods: In the resting state, $^{99m}Tc-ECD$ brain SPECT scans were performed on 10 normal volunteers (9 males, 1 female, mean age 26.6$\pm$0.5 years; age range from 26 to 27 years). On the other day, 7 days after the resting examination, 15 minute TENS were applied at LI 4 and LI 11 on the right side of the subjects. Immediately after LI4-LI11 TENS, the second SPECT images were obtained in the same manner as the resting state. Significant increases and decreases of regional cerebral blood flow after LI4-LI11 TENS were estimated by comparing their SPECT images with those of the resting state using paired t statistics at every voxel, which were analyzed by statistical parametric mapping with a threshold of p = 0.001, uncorrected (extent threshold: k=100 voxels). Results: TENS applied at right LI4-LI11 increased rCBF in the left somatosensory association cortex (Brodmann area 5, 7). However there was no area where LI4-11 TENS decreased rCBF. Conclusion and suggestions: These results demonstrate that right LI4-LI11 TENS increased rCBF only in corresponding somatosensory association cortex, which was different from the previous results using LI4-11 EA. It is suggested that there be a different mechanism between TENS and EA.

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Quantitative evaluation of collapse hazard levels of tunnel faces by interlinked consideration of face mapping, design and construction data: focused on adaptive weights (막장관찰 및 설계/시공자료가 연계 고려된 터널막장 붕괴 위험도의 정량적 산정: 가변형 가중치 중심으로)

  • Shin, Hyu-Soung;Lee, Seung-Soo;Kim, Kwang-Yeom;Bae, Gyu-Jin
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.15 no.5
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    • pp.505-522
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    • 2013
  • Previously, a new concept of indexing methodology has been proposed for quantitative assessment of tunnel collapse hazard level at each tunnel face with respect to the given geological data, design condition and the corresponding construction activity (Shin et al, 2009a). In this paper, 'linear' model, in which weights of influence factors are invariable, and 'non-linear' model, in which weights of influence factors are variable, are taken into account with some examples. Then, the 'non-linear' model is validated by using 100 tunnel collapse cases. It appears that 'non-linear' model allows us to have adapted weight values of influence factors to characteristics of given tunnel site. In order to make a better understanding and help for an effective use of the system, a series of operating processes of the system are built up. Then, by following the processes, the system is applied to a real-life tunnel project in very weak and varying ground conditions. Through this approach, it would be quite apparent that the tunnel collapse hazard indices are determined by well interlinked consideration of face mapping data as well as design/construction data. The calculated indices seem to be in good agreement with available electric resistivity distribution and design/construction status. In addition, This approach could enhance effective usage of face mapping data and lead timely and well corresponding field reactions to situation of weak tunnel faces.