• Journal of the Korean earth science society
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• v.25 no.4
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• pp.251-264
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• 2004

The Charnockite in Sancheong region is quarzofeldspathic rock containing orthopyroxene and garnet with a color dark than common granitic rocks. The Chamockite are mostly massive and medium to coarse-grained with K-feldspar phenocryst, but reveal weak foliation. The rock consist mainly of quartz, K-feldspar, plagioclase and orhopyroxene, with biotite, garnet, and anthophyllite. In petrochemistry, the Chamockite has 61-65% $SiO_2$ contents, varying gradually into the margin contacted with orthogneiss, which have compositions of felsic igneous rocks. Major element show almost systematical variation with those of the marginal orthogneisses, except the hornblende gneiss and anorthosite. The Charnockite and orthogneisses show the tholeiitic differentiational trend. Trace and rare earth element abundance patterns in the Charnockite show remarkable negative Sr and Eu anomalies similar to orthogneisses, but different from the hornblende gneiss and anorthosite. Eu contents of the Charnockite are richer than that of orthogneisses. The metamorphic condition of the Charnockite were tested by an orthopyroxene-garnet geotherrnorneter and a plagioclase-garnet geobarometer. Estimated P-T conditions are about $761^{\circ}C$ and 7 kbar at peak metamorphism, but $653^{\circ}C$ and 6.4 kbar at retrograde metamorphism. This suggests that the Charnockite have from an early stage of high-grade metamorphism to represent the granulite facies and then to a late stage medium-grade metamorphism belonging to the amphibolite facies.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.74.2-74.2
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• 2017

Faint quasars are important to test the possibility that quasars are the main contributor to the cosmic reionization. However, it has been difficult to find faint quasars due to the lack of deep, wide-field imaging data. In this poster, we present our efforts to find faint quasars in the ELAIS-N1 field through the deep data (iAB ~ 25) obtained by the Subaru Hyper Suprime-Cam (HSC) Strategic Program survey. To select reliable quasar candidate, we also use the near-infrared (NIR) data of the Infrared Medium-deep Survey (IMS) and the UKIRT Infrared Deep Sky Survey (UKIDSS) - Deep Extragalactic Survey (DXS). Using multiple-band color cuts, we select high redshift quasar candidates. To confirm them as high redshift quasars, candidates are observed by the SED camera for QUasars in EArly uNiverse (SQUEAN) instrument in several medium band filters that can sample the redshifted Lyman break efficiency. The quasar sample will be used to study the growth of BH and stellar mass, the relation between the quasar activity and the host galaxy, and their contribution to the cosmic re-ionization.

• Journal of dental hygiene science
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• v.11 no.5
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• pp.411-416
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• 2011

Streptococcus mutans (S. mutans) is the major causative bacteria in dental caries. Xylitol is effective anticarious natural sugar substitute by inhibiting the virulence of S. mutans. However, long-term xylitol consumption leads to the emergence of the xylitol-resistant (XR) strains which means xylitol is no more inhibited their growth. We therefore confirmed the general characteristics and the virulence factors of the xylitol-sensitive (XS) and XR S. mutans for different concentrations of xylitol. S. mutans KCTC 3065 was maintained in TYE medium containing 0.4% glucose with 1% xylitol during 30 days at $37^{\circ}C$, 10% $CO_2$ to form XR strain. The strains were transferred to new medium every 24 hr and the same procedures without xylitol were repeated for the formation of XS S. mutans. Both XS and XR were cultured in different concentrations of xylitol (0%, 0.1% and 1%) then, cell growth, acid production and mRNA expression of gtf genes were analyzed. Xylitol reduced the cell growth of XS S. mutans in dose-dependent manner, but not reduced that of XR. Xylitol inhibited acid production of XS in dose-dependent manner, but not inhibited that of XR. Xylitol reduced the gtfB and gtfD mRNA expression of XS S. mutans which genes synthesized soluble and insoluble extracellular polysaccharides, but not reduced that of XR. These results indicate that the virulence of XR S. mutans is different characters of XS strains, which suggests XR strains may have different cariogenicity of XS strains. Further study is needed to explain the mechanism related to extracellular polysaccharide in the XR strains.

• Korean Journal of Environment and Ecology
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• v.26 no.6
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• pp.868-875
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• 2012

This study was carried out to analyze the vegetation properties, soil characteristics and ordination of Hemerocallis hongdoensis population in South Korea. The Hemerocallis hongdoensis population was classified into Mallotus japonicus dominant population, Viburnum wrightii dominant population, Melampyrum setaceum dominant population. Hemerocallis hongdoensis were mainly distributed along the coast of south-western iland of the Korean penninsula and it's population was located at an elevation of 6m to 362m. In the study sites, soil organic matter, total nitrogen, exchangeable potassium, exchangeable calcium, exchangeable magnesium, cation exchange capacity and soil pH were 16.18~21.70%, 0.56~0.97%, 0.42~0.88mg/kg, $3.38{\sim}5.65cmol^+/kg$, $1.12{\sim}2.38cmol^+/kg$, $25.93{\sim}41.45cmol^+/kg$, and 4.45~4.86 respectively. Mallotus japonicus dominant population was found in the steep sloped area that has high percentage of cation exchange capacity and total nitrogen than other populations. Viburnum wrightii dominant population was found gentle sloped area that has low percentage of cation exchange capacity and total nitrogen. Melampyrum setaceum dominant population was found in the medium sloped area that has medium percentage of cation exchange capacity and total nitrogen. Current status of Hemerocallis hongdoensis habitats is very vulnerable with local development constantly threatening the species' survival. Thus, concrete conservation plans to protect natural habitats should be set up as soon as possible.

• Journal of Plant Biotechnology
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• v.40 no.4
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• pp.217-223
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• 2013

Pueraria lobata, a medicinally important leguminous plant produces various isoflavones including puerarin, daidzin and daidzein which are metabolized to equol via dihydrodaidzein and tetrahydrodaidzein by the bacterial fermentation of natural isoflavone sources in human intestines. In this study, we described callus proliferation and isoflavone production in callus of Korean wild arrowroot and dihydrodaidzein biosynthesis in callus extract fermented with Pediococcus pentosaceus. Proliferation was the best at callus cultured in the medium containing 1.0 mg/L TDZ and 1.0 mg/L NAA at light condition for 12 days. Puerarin was significantly more produced at callus cultured in the medium containing 2.0 mg/L kinetin and 1.0 mg/L NAA at dark condition for 16 days, but daidzin and daidzein were not significant. Callus extract was successfully fermented with P. pentosaceus and dihydrodaidzein, which is one of equol precursors formed by biotransformation, was confirmed to be produced. These results will facilitate mass production of callus and isoflavones as equol precursors from Korean wild arrowroot and can be applied for the production of equol by biotransformation in vitro.

• Herbal Formula Science
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• v.24 no.1
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• pp.17-30
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• 2016

Objectives Rehmanniae Radix Preparata was prepared in the traditional Rehmanniae Radix Preparata preparation method set forth in the 『Treasured Mirror of Eastern Medicine(Donguibogam)』 with a view to measuring the contents of 5-Hydroxymethyl-2-furaldehyde(5-HMF) at individual stages of steaming and sundrying and identifying new chemical components.Methods Based on the traditional Rehmanniae Radix Preparata preparation method set forth in the 『Treasured Mirror of Eastern Medicine』, Rehmanniae Radix Preparata steamed and sundried once through nine times was prepared. Thereafter, 5-HMF contents were analyzed and new chemical components were identified in the Rehmanniae Radix Preparata using Waters HPLC e2695, 2640 detectors, a Waters Acquity UPLC system, and a Micromass Q-TOF Premier mass spectrometer.Results The Rehmanniae Radix Preparata preparation method set forth in the 『Treasured Mirror of Eastern Medicine』 is a unique preparation method in Republic of Korea different from that in China. In the first stage of the method, fresh Rehmanniae Radix Crudus was divided into high quality, medium quality, and low quality ones named Rehmanniae Radix Crudus (Caelum)(天黃), Rehmanniae Radix Crudus (Homo)(人黃), and Rehmanniae Radix Crudus (Terra)(地黃) respectively to use Rehmanniae Radix Crudus (Caelum) and Rehmanniae Radix Crudus (Homo) for preparation of juice while using Rehmanniae Radix Crudus (Terra) to make Rehmanniae Radix Preparata. In the second stage, Rehmanniae Radix Crudus (Caelum) and Rehmanniae Radix Crudus (Terra) were made into juice and Rehmanniae Radix Crudus (Terra) was soaked in the juice. In the third stage, among auxiliary materials, rice wine named Purum Vinum Oryzae(淸酒) brewed from sticky rice was sprinkled on Rehmanniae Radix Crudus (Terra) to the extent that Rehmanniae Radix Crudus (Terra) became wet. In the fourth stage, Rehmanniae Radix Preparata steamed in earthenware steamer was dried under natural sunlight. The contents of 5-HMF in Rehmanniae Radix Preparata steamed and sundried once through nine times were shown to be below 0.1% in all cases. Pomolic acid was identified as a new chemical component.Conclusions In conclusion, the Rehmanniae Radix Preparata preparation method set forth in the 『Treasured Mirror of Eastern Medicine』 is thought to be a unique preparation method in South Korea in which Rehmanniae Radix Preparata is completed through the first stage in which fresh Rehmanniae Radix Crudus collected from fields is divided into high, medium, and low quality ones and fresh Rehmanniae Radix Crudus juice is made, the second stage in which the high quality fresh Rehmanniae Radix Crudus is soaked in the fresh Rehmanniae Radix Crudus juice, the third stage in which the fresh Rehmanniae Radix Crudus is steamed, and the fourth stage in which the steamed Rehmanniae Radix Crudus is dried.

• Journal of Veterinary Clinics
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• v.23 no.2
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• pp.123-128
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• 2006

Production of cloned pigs by somatic cell nuclear transfer (SCNT) has unlimited value for developing critical biotechnology such as xenotransplantation. Various efforts have been made to establish this technology, and several litters of live piglets have been produced after transfer of SCNT embryos. However, the efficiency is very low compared to piglet production by artificial insemination or natural mating. So far, most studies have been limited to in vitro production of SCNT embryos. This study was conducted to standardize a surrogate recipient (gilts) for transfer of SCNT embryos to improve pregnancy rate. Potential surrogate gilts over 7 months of age were checked for their estrous status by observing external signs; vaginal fluid, vulva redness, vulva swelling, and standing response to back pressure. Viscosity of vaginal fluid was evaluated and classified as none (0), medium (1), and strong (2). Vulva redness and swelling was respectively assessed by none or shrink (0), medium (1), strong (2). Back pressure was estimated by an immediate move (0), standing less than 10 sec (1), and standing over 10 see (2). And then ovulation status of each surrogate was classified as pre-ovulation (PO-17 surrogates), just prior to ovulation (JPO-20 surrogates), in ovulation (IO-12 surrogates), just after ovulation (JAO-14 surrogates) and after ovulation (AO-24 surrogates) at the time of surgery for embryo transfer (ET). Real-time ultrasonographic scanners have been used for pregnancy diagnosis by observing amniotic vesicles. The first pregnancy diagnosis was done on Day 30 after ET and then repeated 2-week interval. In the results, SCNT embryos transferred into JPO surrogates gave better pregnancy rates (45%) than others (4% to 11%) on Day 30 after ET. These result indicates that surrogate gilts in a status just prior to ovulation can offer optimal condition to establish pregnancy by transfer of SCNT pig embryos.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.3
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• pp.94-106
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• 2008

As populations inhabiting in natural ecosystem are fragmented by artificial barriers and habitats are destructed by development, extinction possibility of species is getting higher. It is necessary to design and to manage conservation areas and corridors considering animals' movement and migration for sustainable species diversity in present circumstances. 'Least-cost modeling' is one commonly employed approach in which dispersal costs are assigned to distinct habitat types and the last-costly dispersal paths among habitat patches are calculated using a geographical information system (GIS). This study aims to design ecological corridor using least-cost path method and to apply it to a regional ecological network considering movability of medium-large size mammals. This study was carried out over the metropolitan area, which has been deforested by rapid urbanization. Nevertheless there is connected with Gangwon province, Baekdudaegan mountain range and DMZ, considered where many forest species can migrate to this region. This study employs such an approach to develop least-cost path models for medium-large size mammals, have inhabited for this entire region. Considering those species, two forest areas as a source of species supply and forest areas more than 1,000ha are selected as focal forest areas. Movement and migration paths from species supply sources to focal forest areas are calculated by applying landscape permeability theory using land cover map, road density map and land slope map. Results showed least-cost paths from species supply sources to focal forest areas on two species. Wildcat and roe deer are different in some least-cost paths caused by their landscape permeability but paths show generally same specifics. The result of considering regional distribution of expected movement and migration paths to regional ecological network, low altitude mountains of western metropolitan area are evaluated important area for species connectivity. In national or regional levels ecological connectivity is essential to promote species diversity and to preserve integrated ecosystem. This study concludes that developing least-cost models from similar empirical data could significantly improve the utility of these tools.

• Korean Journal of Environmental Agriculture
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• v.18 no.3
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• pp.265-271
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• 1999

The direct seeding of seeds or the pellets of three native tree species (Pinus densiflora, Parthenocissus tricuspidata and Rhus chinensis) was tried on the rock cut-slope revegetation bed established by construction of mechanical excavation or erosion break with artificially enriched soil medium. The seed $pellet(1{\sim}2\;cubic\;cm)$ made by coating seeds(treated with proper previous pregermination treatments) with the mixture of peatmoss, clay, chemical absorbant(3.5:1.0:0.2, v/v) showed about twice better percent germination than the control seeds. The percent germination and the survival rate of the germinated seedlings were higher in the spring direct seeding than the summer or the fall. The soil medium containing the compost showed extremely low percent $germination(0{\sim}3%)$ which presumably attributed to the compost inducing damping-off disease. The survival rates were affected mainly by shading of natural herbaceous vegetation invading from outside to the revegetation bed. The planting of two year old container seedlings of P. densiflora and P. tricuspidata on August 2, 1998 was successful indicating that it could be an alternative revegetation method in case the summer direct seeding is unfavorable.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.64-69
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• 2007

In the present study, we have investigated the effect of fisetin on the apoptosis and DNA single strand breaks in ultraviolet light B (UVB)-exposed NIH3T3 cells. Exposure of cells to UVB light $(200J/m^2)$ and post-incubation in growth medium for 48 hr resulted in about 50% of cells with apoptotic nuclear fragmentation. Addition of various concentrations of fisetin in the postincubation medium, however, significantly reduced the apoptotic nuclear fragmentation as compared with the values expected when the effects are additive and independent. DNA single strand breaks induced by UVB exposure were also significantly decreased by postincubation with fisetin. By Western blot analysis, fisetin post-incubation was shown to attenuate the p53 upregulation upon UVB exposure. Furthermore, the decrease of proliferating cell nuclear antigen (PCNA) level upon UVB exposure was alleviated by fisetin postincubation. These results suggest that fisetin decrease the apoptosis and increae DNA repair in a possible association with alteration of p53 and PCNA levels in UVB-exposed cells.