• Korean Journal of Soil Science and Fertilizer
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• 제39권5호
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• pp.245-252
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• 2006

This experiment was conducted to investigate the distribution and compositions of clay mineral and to replenish the soil classification system in Korea. Soil layer samples were collected from 26 residuum and colluvium soil series out of 390 soil series in Korea, and then analyzed for soil physical and chemical characteristics, mineral and chemical compositions of clay in B horizon soils. Major clay minerals of residuum and colluvium were illite and chlorite in soils originated from the sedimentary rock such as limestone, shale, sandstone and conglomerate; quartz and kaolin in soils originated from rhyolite, neogene deposits, porphyry and tuff; and kaolin and quartz in the soils originated from granite, granite gneiss and anorthosite. Clay minerals in Korean soils were divided into 4 groups: mixed mineral group(MIX) mainly contained with illite, kaolin and vemiculite; kaolin group(KA) with kaolin and illite; chlorite group(CH) with chlorite and illite; and smectite group(SM) with kaolin, illite and smectite. The most predominant clay mineral group was kaolin group(KA) with kaolin and illite; an mixed mineral group(MIX) with illite, kaolin and vemiculite. Cation exchange capacity (CEC) of clay was low in the soils mainly composed with MIX and KA groups and silica-alumina molar ratio of clay was high in the soils composed with SM group

• Journal of Life Science
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• 제26권7호
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• pp.749-757
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• 2016

This study was carried out to reveal the genetic population structure of the Jeju Island population and the phylogenetic relationship of East Asian populations of the large-footed bat (Myotis macrodactylus) based on the genetic polymorphisms of mitochondrial cytochrome B (CYTB) and NADH dehydrogenase subunit 1 (ND1) gene sequences. A total of fourteen and nine haplotypes were found in the CYTB and ND1 sequences from East Asian bats, respectively. Haplotype distribution showed locality specific patterns. The results from ND1 haplotype analysis showed that the Jeju Island population has four haplotypes: the Mt. Halla and Western subpopulations have three ND1 haplotypes, but the Eastern subpopulation has just a single haplotype Nd03, which is commonly found on this island. The neighbor-joining (NJ) tree showed the closer relationship between Jeju Island and Japan rather than that between Jeju and Gangwon-do Province. The divergence time between the maternal ancestor lineages of Japanese and Chinese populations was estimated to be 0.789±0.063 MYBP. The secondary divergence between Jeju and Japanese bats was calculated about to be 0.168±0.013 MYBP. The Jeju population has immigrated to the island at least fifty thousand years ago. In addition, ND1 haplotype analysis suggested that the insular bats have experienced at least two further genetic differentiation events within this island. Consequently, these findings suggested that the results of this study may play a critical role in understanding the phylogenetic relationship among East Asian bat populations of M. macrodactylus. To prepare more explainable information on evolutionary correlation, analysis is still required to examine using expanded samples from China, Russia, and southern parts of the Korean Peninsula.

• The Journal of the Korea Contents Association
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• 제9권6호
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• pp.237-246
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• 2009

This study was carried out to investigate of the associations of Alcoholic & Nonalcoholic fatty liver disease(AFLD & NAFLD) with metabolic syndrome(MS) defined by IDF criteria. We conducted a cross-sectional study of 799 adult males with alcohol consumption underwent laboratory investigation(control 297, alcoholic 206, nonalcoholic 296). The ultrasound scan of the liver was performed to determine the presence and the severity of FLD. We analyzed the association between the severity of AFLD & NAFLD and MS by logistic regression analysis. The distribution of metabolic syndrome was 7.4%, 48.8%, 34.9% in control, AFLD & NAFLD. The association of blood pressure, glucose, triglycerides, obesity were risk factor in AFLD & NAFLD. According to the severity of FLD, AFLD was significantly increased with MS, Obesity, low HDL-cholesterol. MS, High triglycerides was increased significantly in NAFLD(p<0.05). The prevalence of AFLD & NAFLD was increased with increasing the number of features of metabolic syndrome. This study shows that AFLD & NAFLD was closely associated with MS and its components. The patients of AFLD & NAFLD should managed and monitored to prevent metabolic abnormalities.

• Journal of agriculture & life science
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• 제44권6호
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• pp.27-37
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• 2010

This study was carried out to offer the basic information on ecological succession of evergreen broad-leaved forest through understanding of ecological characteristics of forest community by distance from Camellia japonica stand. Importance value of C. japonica at tree layer was highest in site I and those of Pinus densiflora and P. thunbergii were highest in site II, III and IV. At subtree layer, the importance value of C. japonica was highest in site I while Neolitsea sericea and Styrax japonica had the highest importance value in site II, III, and IV. In all sites, species diversity ranged from 0.121 to 0.515 and 1.112 to 1.589 at tree layer and subtree layer respectively. Evenness ranged from 0.811 to 0.930 at subtree layer, 0.796 to 0.913 at shrub layer and 0.155 to 0.727 at tree layer, this indicates that distribution pattern by species is more uniform at subtree and shrub layer than at tree layer. Soil pH was highest as 5.72 at site I. Contents of total N, organic matter and available P were higher at site I than other sites.

• Geophysics and Geophysical Exploration
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• 제8권1호
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• pp.86-91
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• 2005

We present the results of electrical resistivity surveys carried out to estimate the seasonal variation of the water table level in a large-scale landslide area of Tertiary geology in Japan. One long profile, trending NE-SW, was established perpendicular to the main regional geology of the region. Three boreholes are located very close to the profile. The profile was surveyed twice, once before snowfall and once after snow had melted. The relationship between resistivity and water saturation of pyroclastic materials was clarified through laboratory tests. We did this in order to estimate the water content of the pyroclastic layer from the observed resistivity distribution in the landslide area. The resistivity of the saturated pyroclastic deposit calculated using an empirical formula was found to be $570{\Omega}.m$. Based on this computed resistivity, the groundwater level was deduced by assuming that the pyroclastic deposits were fully saturated beneath the water table. We show that the estimated water table before snowfall is lower than that inferred after snow has melted, by about 1.1 to 4.7 m. This suggests that the water table in the upper part of the pyroclastic layer in the landslide area fluctuates greatly, compared to the lower part. This seasonal groundwater fluctuation is possibly caused by the infiltration of water into the subsurface after snowmelt.

• Korean Journal of Soil Science and Fertilizer
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• 제19권3호
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• pp.205-210
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• 1986

A soil micromorphological study of clayey terrace soils in Yeongnam area was carried out to investigate the soil genetic features and to distinguish the soil parent materials. Dominant plasmic fabrics in the terrace soils were vosepic, mosepic, insepic, and masepic of sepic fabrics but the Geugrag and Upyeong in Yeongil sequence have an asepic fabrics. Embedded grain cutans in the terrace soils were characterized by having porphyroskelic related distribution. Among pedological features of the B horizons of the terrace soils, the argillic cutans of ferriargillans and glaebules of manganiferrous concretions were the dominant in mineralogical composition, and the papules are abundant in the most terrace soils indicating that the soils are generally old. The substrata of the Bancheon in Yeongcheon and Upyeong in Yeongil area were so different from the terrace deposits in plasmic fabrics that these soils were believed to be composed of bisequum profiles. Because of having the free grain cutans, it was considered that the substrata of Bancheon in Yeongcheon and Upyeong in Yeongil area might have a period of soil formation before deposition of the terrace materials.

• Korean Journal of Remote Sensing
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• 제37권5_2호
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• pp.1307-1315
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• 2021

The Changjiang Diluted Water (CDW) spreads over the East China Sea every summer and significantly affects the sea surface salinity changes in the seas around Jeju Island and the southern coast of Korea peninsula. Sometimes its effect extends to the eastern coast of Korea peninsula through the Korea Strait. Specifically, the CDW has a significant impact on marine physics and ecology and causes damage to fisheries and aquaculture. However, due to the limited field surveys, continuous observation of the CDW in the East China Sea is practically difficult. Many studies have been conducted using satellite measurements to monitor CDW distribution in near-real time. In this study, an algorithm for estimating Sea Surface Salinity (SSS) in the East China Sea was developed using the Geostationary Ocean Color Imager (GOCI). The Multilayer Perceptron Neural Network (MPNN) method was employed for developing an algorithm, and Soil Moisture Active Passive (SMAP) SSS data was selected for the output. In the previous study, an algorithm for estimating SSS using GOCI was trained by 2016 observation data. By comparison, the train data period was extended from 2015 to 2020 to improve the algorithm performance. The validation results with the National Institute of Fisheries Science (NIFS) serial oceanographic observation data from 2011 to 2019 show 0.61 of coefficient of determination (R²) and 1.08 psu of Root Mean Square Errors (RMSE). This study was carried out to develop an algorithm for monitoring the surface salinity of the East China Sea using GOCI and is expected to contribute to the development of the algorithm for estimating SSS by using GOCI-II.

• Korean Journal of Environmental Biology
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• 제36권4호
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• pp.638-646
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• 2018

The purpose of this study was to investigate the long-term habitat morphological alteration resulting from a large dam and weirs in the Tamjin River. To achieve this, we carried out a hydrograph analysis and a substrate size distribution analysis. We also estimated the channel width, bar area and vegetation encroachment using aerial photographs taken before and after the construction of the dam and weirs. The result of the hydrological analysis showed that flooding downstream was greatly reduced with small peaks occurrence after the dam construction. Interestingly, normal hydrographs in the main channel appeared just after tributary conjunction. There was a similar pattern in the substrate size analysis. Despite coarsened substrate just downstream of the dam site, more sand appeared again after introduction of the tributary. However, there was an increase in the bar area downstream of the dam's channels with most bars covered with vegetation. The channel width increased at the upper area of weirs through impoundment, but decreased downstream because of vegetation encroachment. This study indicate that unregulated tributary plays an important role in restoring hydro-physical habitat conditions in mainstream channels below a large dam. However, numerous weirs could be a causal factor to accelerate habitat deterioration in the dam downstream channels.

• The Journal of Korean Medicine
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• 제40권2호
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• pp.17-34
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• 2019

Objectives: This study was carried out to observe and compare the effects of Pinellia ternata, Zingiber officinale and Sobanhatang on the reflux esophagitis induced by gastric fundus and pylorus ligation in mice with esomeprazole. Methods: Antioxidant effects were measured by DPPH radical scavenging activity at four different concentration of 0.125, 0.25, 0.5 and $1.0mg/102{\mu}{\ell}$. Zingiber officinale water extract(ZE), Pinellia ternata water extract(PE) and Sobanhatang water extract(SBE) and esomeprazole were treated orally for 14 days before gatric fundus and pylorus ligation. In the histochemistry, changes in suface mucous cells, muscle tissue and connective tissue in gastro esophageal junction(GEJ) and mast cell on the esophageal mucosa were observed. The change of Hemo oxygenase(HO)-1, ghrelin, gastrin and substance P in gastric body tissue were measured by immunohistochemistry. Results: DPPH radical scavenging activity exhibited concentration dependently increases in ZE, PE, SBE. ZE was significantly higher at all concentrations than PE. The gastric surface mucous cells were more in the treated group than in the reflux esophagitis elicited group(GE) in the order of PE, SBE, ZE and esomeprazole treateded group(PT, SBT, ZT, ET). Lower esophageal sphincter muscle damage and intercellular space in the GEJ were less in the treated group than GE. In the esophageal mucosa, the mast cell distribution and the migration of inflammatory cells were lower in the treateded troup than GE in order to ZT, SBT, PT and ET. The antioxidative enzyme, HO-1 was more in the order of ZT, SBT, control group, PT, ET than in GE. ZT was significantly higher than the other groups and SBT was significantly higher than ET. Ghrelin was found to be higher in ZT, ET, SBT and PT than in GE, and ZT was significantly higher than all other groups except ET. Gastrin showed the highest positivity in GE, and was lower in the order of ET, ZT, SBT, PT, and control group. Substance P was the highest in GE, and was lower in the order of ET, ZT, SBT, PT and control group, and PT were significantly lower than ET. Conclusion: ZT, PT and SBT showed superior antioxidative, anti-inflammatory and mucosal protective effects on mouse reflux esophagitis as compared with ET. In particular, ZE was more effective in antioxidant and gastric motility enhancement, while PE was more effective in mucosal protection and anti-inflammatory effects. Sobanhatang is expected to be effective treatment because it has advantages of both drugs and reduces toxicity.

• Journal of Korean Society on Water Environment
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• 제34권6호
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• pp.632-641
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• 2018

Algal dynamics is controlled by multiple environmental factors such as flow dynamics, water temperature, trophic level, and irradiance. Underwater irradiance penetrating from the atmosphere is exponentially decreased in water column due to absorption and scattering by water molecule and suspended particles including phytoplankton. As the exponential decrease in underwater irradiance affects algal photosynthesis, regulating their spatial distribution, it is critical to understand the light extinction characteristics to find out the mechanisms of algal dynamics more systematically. Despite the significance, the recent data have been rarely reported in the main stream areas of large rivers, Korea. In this study, the euphotic depths and light extinction coefficients were determined by monitoring the vertical variation of underwater irradiance and water quality in the main channel of Nakdong River near Dodong Seowon once a week during summer of 2016. The average values of euphotic depth and light extinction coefficient were 4.0 m and $1.3m^{-1}$, respectively. The degree of light extinction increased in turbid water due to flooding, causing an approximate 50 % decrease in euphotic depth. Also, the impact was greater than the self-shading effect during the periods of cyanobacterial bloom. The individual light extinction coefficients for background, total suspended solid and algal levels, frequently used in surface water quality modeling, were determined as $0.305m^{-1}$, $0.090m^{-1}/mg{\cdot}L^{-1}$, $0.013m^{-1}/{\mu}g{\cdot}L^{-1}$, respectively. The values estimated in this study were within or close to the ranges reported in literatures.