• The Journal of the Petrological Society of Korea
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• v.2 no.1
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• pp.41-52
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• 1993

We report adventages of employing MgO as a differentiation index for the Namwon granitic complex. It is shown to be much more sensitive than the usual Harker index. The complex can be divided into two groups on the basis of $TiO_2$/MgO ratio. The low $TiO_2$/MgO group consists of hornblende biotite tonalite-granodiorite, porphyritic hornblende biotite granodiorite (PHBGd) and part of biotite granite (loBG). PHBGd shows its own distinct variation in the low group. This group is characterized in most cases by the presence of hornblende, even if it occurs as a trace amount. The high $TiO_2$/MgO group consists of part of biotite granite (hiBG) and two mica granite. The major element differences between rock types are also apparent in biotite chemistry. These chemical data indicate that at least two distinct origins of magma are rquired for the complex. Two kinds of biotite granite revealed in this study show distinct geographic distribution, suggesting that a new geologic map should be made.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.4 s.97
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• pp.26-36
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• 1999

A general procedure for determining the optimum location of suspension hard points with respect to kinematic design parametes is presented. Suspensions are modeled as connection of rigid bodies by ideal kinematic joints. Constraint equations of the kinematic joints are expressed in terms of the generalized coordinates and hard points. By directly differentiating the constraint equations with respect to the hard points, kinematic sencitivity equations are obtained. In order to cope with algebraic complexity associated with the differentiation process, a symbolic computation technique is used. A performance index is defined in terms of static design parameters such as camber, caster, toe, ect.. Gradient of the performance index can be analytically computed from the kinematic sensitivity equations. Optimization results show the effectiveness and validity of the procedure, which is applicable to any type of suspension if its kinematic configurations are given.

• Journal of Ginseng Research
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• v.22 no.2
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• pp.91-95
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• 1998

The distribution of phenolic components of Korean ginseng (Panax ginseng KG) and American ginseng (Panax quinquefolium, AG) were compared by thin-layer chromatography (TLC). Silica gel TLC gave 3~4 spots, while $NH_2$ HPTLC 5~6 spots, which were colored by both $FeCl_3$/$K_3Fe(CN)_6$ and Folin-Ciocalteu. The distribution of phenolic components was quite different between KG and AG. Especially, a polyphenol (m.w. 578), which had been isolated from KG by the author, was not found in AG. This result suggests that the polyphenol could be used as an index compound for the differentiation of KG from AG.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.10a
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• pp.101-108
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• 2000

An optimum design algorithm using efficient reanalysis is proposed for reliability-based optimization problems formulated as the minimization of initial cost and expected failure cost with reliability constraints. The reliability-based optimization is high cost to evaluate objective function and constraints needed reliability analysis. Therefore the sensitivity analysis of reliability index for approximated reanalysis is necessary. In this paper, three solution approaches are suggested and tested. The approaches include : (1) sensitivity analysis using finite difference; (2) sensitivity analysis using automatic differentiation (AD); and (3) sensitivity analysis with respect to intermediate variables using AD. Numerical example is optimized to show the reliability and effectiveness of the new algorithm.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.683-692
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• 2010

Morphologically, nine different slow-growing protoclones were screened from regenerated protoplasts of heterokaryotic Agaricus bisporus. As such, the present study is the first report on differentiating homo- and heterokaryotic protoclones using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers. Among 80 primers tested, the seven ISSR and seven RAPD primers selected for the analysis generated a total of 94 ISSR and 52 RAPD fragments, respectively. The ISSR fingerprinting also detected more polymorphic loci (38.29%) than the RAPD fingerprinting (34.61%). A principal coordinate analysis (PCA) was employed to evaluate the resolving power of the markers as regards differentiating protoclones. As a result, the mean polymorphism information content (PIC) for each marker system (i.e., 0.787 for RAPD and 0.916 for ISSR) suggested that ISSR is more effective for determining polymorphisms. The dendrograms constructed using RAPD, ISSR, and an integrated RAPD and ISSR marker system were highly correlated with one another as revealed by a high Mantel correlation (r= 0.98). The pairwise similarity index values also ranged from 0.64 to 0.95 (RAPD), 0.67 to 0.98 (ISSR), and 0.67 to 0.98 (RAPD and ISSR), whereas the mean similarity index values of 0.82, 0.81, and 0.84 were obtained for the RAPD, ISSR, and combined data, respectively. As there was a good correspondence between the RAPD and ISSR similarity matrices, ISSR would appear to be an effective alternative to RAPD in the genetic diversity assessment and accurate differentiation of homo- and heterokaryotic protoclones of A. bisporus.

• Journal of Aquaculture
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• v.20 no.4
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• pp.255-259
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• 2007

Genetic diversity among four populations of Chinese shrimp Fenneropenaeus chinensis from Narodo, Yeonggwang, Taean and Chinese Bohai Bay was assessed by amplified fragment length polymorphism (AFLP) DNA fingerprinting. Total numbers of AFLP bands generated (ranging from 251 to 254) and average percent of polymorphic bands (27.1 to 28.1 %) were similar in the four populations. Heterozygosity and genetic diversity within or among the populations were very low for the populations with average values ranging from 0.1177 to 0.1288 and from 0.1099 to 0.1194, respectively. Analyses of pairwise distance, Fst index and genetic similarity among the populations also revealed the similar results with very low genetic differentiation each other. These results suggest that all the wild populations tested in the present analysis may be belonging to the same genetic origin, and also that they may have a close relationship in genetic structure without any significant differentiation.

• Journal of Aquaculture
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• v.21 no.3
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• pp.196-200
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• 2008

Korean spotted barbel Hemibarbus mylodon, is an endangered and endemic freshwater species in the Korean peninsula. Amplified fragment length polymorphism (AFLP) was used to analyze the genetic diversity and population genetic structure of three populations (Bukhan, Namhan and Imjin-river). Fifteen AFLP primer pairs produced 795 products of which 135 were polymorphic(17%). Percentages of polymorphic bands were similar among the three populations, with accounting 11.9%, 11.1%, and 13.4% for Bukhan, Namhan and Imjin-river populations, respectively. An average genetic similarity among the three populations was 0.969. The average heterozygosity (0.033-0.040) and genetic diversity (0.036-0.043) were significantly low. Pairwise distance and fixation index analyses of three populations also suggested quite a low genetic differentiation one another. These results would provide a fundamental baseline data to develop the effective strategy for the management and restoration of this endangered fish species.

• International Journal of Oral Biology
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• v.30 no.3
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• pp.105-110
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• 2005

Periodontitis is a chronic infectious disease that leads to the destruction, one of the major cause of tooth loss in human. Osteoclast Differentiation Factor(ODF), also called as Receptor activator of NF-${\kappa}B$ ligand(RANKL), a surface-associated ligand on bone marrow stromal cells and osteoblasts, activates its cognate receptor RANK on osteoclast progenitor cells, which leads to differentiation of these mononucleated precursor cells. Osteoprotegerin(OPG), a decoy receptor, is released from stromal cells and osteoblasts to inhibit the interaction between RANKL and RANK. The experiment for the effect of pregnancy on gingival health showed greater gingival inflammation and edema during pregnancy, despite similar plaque index. There should be many factors affecting the periodontal health in pregnancy. In this experiment, we examined the direct effects of sex hormones(estrogen and progesterone) on the ODF/OPG expression in human gingival fibroblasts and periodontal ligament cells at the serum concentration of pregnancy. The ratio was high in the 1st trimester of pregnancy by estrogen and in the late 2nd trimester by progesterone. Therefore, the local periodontal destruction might be accelerated by these hormonal effect on the periodontal cells.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.2
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• pp.120-128
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• 2021

The objective of this study was to analyze the genotype of black-spotted pond frog (Pelophylax nigromaculatus) using seven microsatellite loci to quantify its genetic diversity and population structure throughout the spatial scale of basins of Han, Geum, Yeongsan, and Nakdong Rivers in South Korea. Genetic diversities in these four areas were compared using diversity index and inbreeding coefficient obtained from the number and frequency of alleles as well as heterozygosity. Additionally, the population structure was confirmed with population differentiation, Nei's genetic distance, multivariate analysis, and Bayesian clustering analysis. Interestingly, a negative genetic diversity pattern was observed in the Han River basin, indicating possible recent habitat disturbances or population declines. In contrast, a positive genetic diversity pattern was found for the population in the Nakdong River basin that had remained the most stable. Results of population structure suggested that populations of black-spotted pond frogs distributed in these four river basins were genetically independent. In particular, the population of the Nakdong River basin had the greatest genetic distance, indicating that it might have originated from an independent population. These results support the use of genetics in addition to designations strictly based on geographic stream areas to define the spatial scale of populations for management and conservation practices.

• Korean Journal of Plant Taxonomy
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• v.53 no.1
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• pp.14-24
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• 2023

Saussurea dorogostaiskii Palib. (Asteraceae) is a critically endangered medicinal plant in Mongolia and Russia. We studied the genetic variation of S. dorogostaiskii from three mountains of northern Mongolia. The genetic profile was assessed in 70 individuals from eight populations using five inter-simple sequence repeat markers, producing 53 loci with 96.4% polymorphism across all bands. Shannon's index (I) and Nei's gene diversity (H) value at the species level of S. dorogostaiskii are 0.25 and 0.17, respectively. An AMOVA showed high genetic variation among the populations (22% of populations and 32% of mountains), consistent with the high genetic differentiation (G_ST = 0.49) and low gene flow (N_m = 0.51) in S. dorogostaiskii populations. Eight populations were clustered into two groups, corresponding to their geographic locations. The low within-population genetic diversity and high genetic differentiation among S. dorogostaiskii populations factor into their endangered designation. This genetic analysis reveals that all populations are equally threatened, and community-based conservation is appropriate for these species.