• Journal of Life Science
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• v.21 no.3
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• pp.468-472
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• 2011

DNA marker is a powerful tool for plant genetics and breeding. In this study, 995 SSR markers were employed with chilling resistant cucumber, known as 'NC76', and chilling susceptible cucumber, known as 'GY14'. Using 2% agarose gel electrophoresis, 145 SSR markers were identified as length variation markers between 'NC76' and 'GY14'. The SSR markers that showed no length polymorphism were then screened using high resolution melting analysis technique and additional 30 polymorphic SSR markers were identified. As a preliminary evaluation for mapping, 20 markers among these 175 markers were employed to a $F_2$ population of 'NC76' x 'GY14' cross. Linkage analysis revealed 13 markers that joined into six linkage groups and seven markers that remained unlinked. This result indicates that these 175 markers could be used for construction of a genetic map using a cross between 'NC76' and 'GY14' for further investigation in developing markers related to resistance to chilling in cucumbers.

• Journal of Crop Science and Biotechnology
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• v.10 no.2
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• pp.98-105
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• 2007

Phylogenetic relationships in Korean watermelons were evaluated by genetic similarity coefficients using 15 SSR(simple sequence repeat), 14 SCAR(sequence characterized amplified region) and 14 CAPS(sequence characterized amplified region) markers. The SSR markers were selected from previously reported melon and watermelon SSRs through testing polymorphisms within a set of commercial $F_1$ varieties. The SCAR and CAPS markers were developed from polymorphic AFLP(amplified fragment length polymorphism) markers between inbred lines 'BN4001' and 'BN4002'. From the AFLP analysis, 105 polymorphic fragments were identified between the inbred lines using 1,440 primer combinations of EcoRI+CNNN and XbaI+ANNN. Based on the sequencing data of these polymorphic fragments, we synthesized sequence specific primer pairs and detected clear and reliable polymorphisms in 27 primer pairs by indels(insertion/deletion) or RFLP(restriction fragment length polymorphism). A total of 43 sequence-based PCR markers were obtained and polymorphic information content(PIC) was analyzed to measure the informativeness of each marker in watermelon varieties. The average PIC value of SCAR markers was 0.41, which was similar to that of SSR markers. Genetic diversity was also estimated by using these markers to assess the phylogenetic relationships among commercial varieties of watermelon. These markers differentiated 26 Korean watermelon varieties into two major phylogenetic groups, but this grouping was not significantly correlated with their morphological and physiological characteristics. The mean genetic similarity was 66% within the complete set of 26 commercial varieties. In addition, these sequence-based PCR markers were reliable and useful to identify cultivars and genotypes of watermelon.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.3
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• pp.302-306
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• 2001

This study was carried out to construct mapping population and to evaluate the methods involved, including polymorphic DNA marker system and appropriate statistical analysis. As an initial step to establish chicken genome mapping project, White Leghorn (WL) and Korean Ogol chicken (KOC) were used for generating backcross population. From 8 initial parents, total 280 backcross progenies were obtained and 40 were used for genotyping and linkage analysis. For development of novel polymorphic markers for KOC, Random Amplified Polymorphic DNA (RAPD) markers specific for this chicken line were generated. Also included in this study were six microsatellite markers from East Lansing map as reference loci. For segregation analysis, 15 RAPD markers and 6 microsatellites were used to genotype the backcross population. Among the RAPD markers that we developed, 2 pairs of markers were identified to be linked and another 4 RAPD markers showed linkage with microsatellites of known map. In summary, this study showed that our backcross population generated from the mating of KOC to WL serves as a valuable genetic resource for genotyping. Furthermore, RAPD markers are proved to be valuable in linkage mapping analysis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.4
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• pp.341-343
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• 2001

Molecular markers have become fundamental tools for crop genome study. The objective of this study was to construct a genetic linkage map for cowpea with PCR-based molecular markers. Five hundred and twenty random RAPD primers were screened for parental polymorphism. Ninety RAPD markers from sixty primers was segregated in 75 F2 mapping population derived from the cross of local cultivars GSC01 and GSC02. 70 RAPD markers were found to be genetically linked and formed 11 linkage groups. Linkage map spanned 474.1 cM across all 11 linkage groups. There are six linkage groups of 40 cM or more, and five smaller linkage groups range from 4.9 to 24.8 cM. The average linkage distance between pairs of markers among all linkage groups was 6.87 cM. The number of markers per linkage group ranged from 2 to 32. The longest group 1 spans 190.6 cM, while the length of shortest group 11 is 4.9 cM. This map is further needed to be saturated with the various markers such as RFLP, AFLP, SSR and more various populations and primers. In addition, morphological markers and biochemical markers should be united to construct a comprehensive linkage map.

• The Korean Journal of Nuclear Medicine
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• v.33 no.4
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• pp.341-351
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• 1999

Biochemical markers of bone turnover has received increasing attention over the past few years, because of the need for sensitive and specific tool in the clinical investigation of osteoporosis. Bone markers should be unique to bone, reflect changes of bone loss, and should be correlated with radiocalcium kinetics, histomorphometry, or changes in bone mass. The markers also should be useful in monitoring treatment efficacy. Although no bone marker has been established to meet all these criteria, currently osteocalcin and pyridinium crosslinks are the most efficient markers to assess the level of bone turnover in the menopausal and senile osteoporosis. Recently, N-terminal telopeptide (NTX), C-terminal telopeptide (CTX) and bone specific alkaline phosphatase are considered as new valid markers of bone turnover. Recent data suggest that CTX and free deoxypyridinoline could predict the subsequent risk of hiP fracture of elderly women. Treatment of postmenopausal women with estrogen, calcitonin and bisphosphonates demonstrated rapid decrease of the levels of bone markers that correlated with the long-term increase of bone mass. Factors such as circadian rhythms, diet, age, sex, bone mass and renal function affect the results of biochemical markers and should be appropriately adjusted whenever possible. Each biochemical markers of bone turnover may have its own specific advantages and limitations. Recent advances in research will provide more sensitive and specific assays.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.154-154
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• 2017

In accordance with the opening of the Korean rice market, this study was focused on establishment of database for discriminating the Korean rice varieties and imported brand rices using DNA markers. In this study, the SNP markers were developed using single nucleotide polymorphisms between the reference sequences of japonica and them of 40 brand rices which collected in Australia, China, Thailand, United States and Vietnam. The developed SNP markers were screened to a total of 360 rices including 320 Korean rice varieties and 40 imported brand rices. We selected polymorphic markers among Korean bred rive varieties and imported brand rices. The selected markers were classified into 3 grades. The markers of A grade produced DNA band in 360 rices of 30~40%, B grades produced in 40~60%, and C grades produced bands over 60% rices. First, we tried to set-up the discriminating system using the minimum SNP markers of A grade. Especially, a set of sixteen SNP markers could identify among Korean bred rice varieties and imported brand rices. Additionally, some SNP markers like NSb for Pib gene, JJ80-T for Pi5 and YL155/YL87 for Pita which linked to resistance genes to blast were used to fingerprinting system. These markers were set-up as multiplex set for enhancing the identification efficiency among rice varieties. Finally, the selected SNP markers would be used to the fluidigm assay to construct the database for elaborate discrimination of rice varieties.

• Mycobiology
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• v.41 no.2
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• pp.86-93
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• 2013

Sequence characterized amplified region (SCAR) markers are one of the most effective and accurate tools for microbial identification. In this study, we applied SCAR markers for the rapid and accurate detection of Phytophthora katsurae, the casual agent of chestnut ink disease in Korea. In this study, we developed seven SCAR markers specific to P. katsurae using random amplified polymorphic DNA (RAPD), and assessed the potential of the SCAR markers to serve as tools for identifying P. katsurae. Seven primer pairs (SOPC 1F/SOPC 1R, SOPC 1-1F/SOPC 1-1R, SOPC 3F/SOPC 3R, SOPC 4F/SOPC 4R, SOPC 4F/SOPC 4-1R, SOPD 9F/SOPD 9R, and SOPD 10F/SOPD 10R) from a sequence derived from RAPD fragments were designed for the analysis of the SCAR markers. To evaluate the specificity and sensitivity of the SCAR markers, the genomic DNA of P. katsurae was serially diluted 10-fold to final concentrations from 1 mg/mL to 1 pg/mL. The limit of detection using the SCAR markers ranged from $100{\mu}g/mL$ to 100 ng/mL. To identify the limit for detecting P. katsurae zoospores, each suspension of zoospores was serially diluted 10-fold to final concentrations from $10{\times}10^5$ to $10{\times}10^1$ zoospores/mL, and then extracted. The limit of detection by SCAR markers was approximately $10{\times}10^1$ zoospores/mL. PCR detection with SCAR markers was specific for P. katsurae, and did not produce any P. katsurae-specific PCR amplicons from 16 other Phytophthora species used as controls. This study shows that SCAR markers are a useful tool for the rapid and effective detection of P. katsurae.

• English Language & Literature Teaching
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• v.9 no.2
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• pp.133-149
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• 2003

As the world becomes a global village, national conferences become more frequent, and the language of choice to mediate the exchange of information is English. Accordingly, the purpose of this research is to find several methods to prepare L2 students for English communication at conferences. Various studies about discourse markers can be found in this study. Discourse markers are indicators of fluency in spoken language, and indicators of improvement from features of spoken English to more typical forms of formal writing. In this study the presentation styles of native speakers and Asian non-native speakers are compared, and the difference between efficient and non-efficient speakers at conferences are discussed. As a study of conference English teaching and learning method, this research targets suggestion and application of discourse markers for L2 speakers. As a result, the fact that discourse markers are very important in effective writing and conference English is found and accordingly we can see that developing the ability to use discourse markers in writing and speaking are essential for L2 speakers.

• Journal of Computational Design and Engineering
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• v.1 no.4
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• pp.289-297
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• 2014

Although big-sized markers are good for accurate marker recognition and tracking, they are easily occluded by other objects and deteriorate natural visualization and level of immersion during user interaction in AR environments. In this paper, we propose an approach to exploiting the use of rectangular markers to support tangible AR interaction based on fingertip touch using small-sized markers. It basically adjusts the length, width, and interior area of rectangular markers to make them more suitably fit to longish objects like fingers. It also utilizes convex polygons to resolve the partial occlusion of a marker and properly enlarges the pattern area of a marker while adjusting its size without deteriorating the quality of marker detection. We obtained encouraging results from users that the approach can provide better natural visualization and higher level of immersion, and be accurate and tangible enough to support a pseudo feeling of touching virtual products with human hands or fingertips during design evaluation of digital handheld products.

• Korean Journal of Agricultural Science
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• v.39 no.2
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• pp.211-217
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• 2012

There is an emerging interest in using DNA markers for breed identification in animals. This article reviews the breed identification markers in chicken, mainly developed in Chungnam National University, with particular emphasis on the mitochondrial DNA markers and the nuclear DNA markers including the SNPs in MHC region and the plumage color related MC1R markers. This information would be very useful for an appropriate conservation breeding program as well as for the establishment of molecular markers for chicken breed identifications.