• Journal of Life Science
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• v.29 no.10
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• pp.1104-1110
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• 2019

Recently, there has been an increase in the elderly population of the world. Consequently, bone metabolic diseases such as osteoporosis are emerging as a social problem. Osteoclasts play a role in bone resorption, and osteoporosis is induced when bone resorption occurs excessively. Because currently used bone resorption inhibitors may cause side effects when used for a long period of time, it is necessary to develop a new material that effectively inhibits osteoclast differentiation. This study aimed to confirm the inhibitory effect of ethanol extract of Locusta migratoria on RANKL-induced osteoclast differentiation and its mechanism. The toxicity and proliferation effects of LME on RAW264.7 osteoclasts were measured by an MTS assay. There was no cytotoxicity or proliferation when the osteoclasts were treated with up to $2,000{\mu}g/ml$ of LME. In order to confirm the effect of LME on the differentiation of osteoclasts, osteoclasts were treated with RANKL alone or with LME for 3 days. As a result of a TRAP (tartrate-resistant acid phosphatase) assay, the increasing osteoclast differentiation by RANKL decreased in a concentration-dependent manner with the treatment of LME. In addition, LME suppressed the expression of differentiation-related marker genes (TRAP, RANK, NFATc1, and CK) and proteins (NFATc1 and c-Src) that had been increased by RANKL. Also, LME influenced the $NF-{\kappa}B$, ERK and JNK signaling pathways, resulting in the inhibition of osteoclast differentiation. These results suggest that LME may be used as a novel functional material for the prevention and treatment of osteoporosis by playing a role in inhibiting bone absorption.

• Ecology and Resilient Infrastructure
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• v.6 no.1
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• pp.12-22
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• 2019

This study investigated the spatial and temporal water circulation characteristics of Paldang Reservoir by continuous hydraulic and water temperature survey. Due to differences in water temperature and discharge pattern of Ipo Weir and Cheongpyeong Dam, the flow and temperature fluctuations were different in sections of Namhan River and Bukhan River in Paldang Reservoir. At the stratification period, the water temperature of the discharge of Ipo Weir was higher than that of the Cheongpyeong Dam. Therefore, in the surface layer of the downstream of Bukhan River, relatively high temperature water is located and back water phenomenon occurred, and convergence zone is formed. In the downstream section of Namhan River, low-temperature water was distributed in the middle and lower layers, and the upstream flow appeared to be difficult to mix with the surface layer.

• Journal of Korean Society on Water Environment
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• v.35 no.2
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• pp.99-104
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• 2019

The objective of this study was to investigate the relationship between the biomass of cyanobacteria and the concentration of 2-methylisoborneol (2-MIB) in the lower Gongji stream. The investigation was done using a field study that was conducted from 2015 to 2017. The 2-MIB concentration in the lower Gongji stream ranged from 0 to 153 ng/L, while the upper stream had 0 2-MIB concentration. 3 genera (Oscillatoria, Phormidium, Pseudanabaena) of cyanobacteria were detected in the lower Gongji stream with 2-MIB concentration. Among these 3 genera, an increase in Phormidium, Pseudanabaena biomass was associated with an increase in 2-MIB concentration. Accordingly, Phormidium, Pseudanabaena were regarded as the biological source of 2-MIB in that area. In October 2017, although planktonic cyanobacteria occurred less frequently, many benthic cyanobacteria mats were observed on the surface of the water body. Therefore, the high 2-MIB concentration, which exceeded 110 ng/L, can likely be attributed to the benthic cyanobacteria. In a laboratory experiment, individual Oscillatoria filaments were aggregated to form a colony with a higher density. This colony tended to float on the water surface. Cyanobacteria mats after floating aggregated mats were distributed in a net shape on the bottom.

• The Journal of the Korea Contents Association
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• v.20 no.1
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• pp.245-258
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• 2020

The study analyzed the frequency, type, and context of violence in 10 school-life webtoon published on Korean portal-site, Naver. Results of content analysis showed 2.15 PAT(Perpetrator-Action-Target) per 1 episode. As for the types of violence, physical violence accounted for 73.2 percent of PATs. As for the characteristics of characters, 53.6 percent of those who committed violence were set to have good-looking. 35.9% of those who committed of violence were heros and 37.3% were villains. The case that perpetrator and target were friends accounted for 60.8%. The case that a travesty is made of the violent scenes adopting excessive expressions, overtures, and balloons accounted for 66.7%. The most common motive for violence was the means for the interests and beliefs of individuals and groups (29.4%), followed by fun (20.9%). The case that the punishment or compensation for violence is absent accounted for 79.9%.

• Journal of Environmental Impact Assessment
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• v.28 no.3
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• pp.215-230
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• 2019

The objective of this research is to evaluate the water quality characteristics using the statistical analysis of major tributaries in the Han River and to provide water quality improvement plan by selecting tributaries that should be preferentially managed by river grade classification method. The major 15 tributaries in Han River watershed were monitored for discharge and water quality during January-December 2017. As a result of the correlation analysis, the river discharge has been not correlation with other water quality constituents (p>0.05) but COD and TOC were significantly correlated (r=0.957, p<0.01). The main cause of water quality fluctuation was organic pollutants and nutrients in the principal component analysis (PCA) method. The BOD, COD, TOC, TN, and TP were found to be significantly different (p<0.05) by seasonal in result of one-way ANOVA analysis. Result of river grade classification by quantitative indicators the tributaries requiring improvement of water quality were Gulpocheon, Anyangcheon, Wangsukcheon, and Tancheon which affected by wastewater treatment plant.In this research, we determined tributaries that need to improve the water quality of Han River watershed and it can be used as an important data for efficient water quality management.

• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.704-716
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• 2018

The aim of this study is to examine the characteristics analysis of the discharge and water quality based on TPLMS (Total Pollution Load Management System) in the Jinwi River unit basin, and to propose a management plan by selecting the point that needs improvement of water quality in order to achieve the target water quality. We evaluated the discharge and water quality characteristics, statistical analysis, daily delivery load and daily delivery density, grade classification, for 14 total pollution load site's from 2014 to 2016 year in Jinwi river unit basin. The average discharge of Jinwi river unit basin is $22.411m^3/s$ and discharge of Hwangguji River is 32.8% and the water quality characteristics along the tributary river were clarified spatially. As the result, it was analyzed that Seongeun River is an indirect indicator of organic pollutants, Gwanri River is a seasonal factor, Osan River and Hwangguji River both affect water quality. Estimation of delivered pollutant loads at the HG-3 site was 6,470.4 BOD kg/day, 6,846.7 TN kg/day and delivered pollutant loads density increased to $220.9BOD\;kg/day/km^2$, $22.4TP\;kg/day/km^2$ at the HG-4 site. This result demonstrates that the total pollution load site needed to improve water quality of the Jinwi River unit basin was HG-3 site.

• Journal of Environmental Impact Assessment
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• v.28 no.1
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• pp.35-48
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• 2019

Long term flow measurement and water quality analysis data need to determine the target and allowable load for each basin in Total Water Pollution Load Management System (TWPLMS). The Load Duration Curve (LDC) is analyzed the relationship between flow data and water quality, and evaluates the pollutant load characterization by flow conditions. LDC of Kyeongancheon is created by the Flow Duration Curve (FDC) that was analyzed 8-day interval measured flow data from 2006 to 2015 and numeric water quality target in Kyeongancheon. As a result of this study, it is necessary to manage the point source pollutant because the numeric water quality target is not satisfied in the low flows. Also the numeric water quality target has been exceed for four months from March to June of the year and continuous and systematic watershed management is required to satisfy the numeric water quality target.

• Journal of Korean Society on Water Environment
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• v.37 no.6
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• pp.510-519
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• 2021

Volatile Organic Compounds (VOCs) in sediments, which can cause human health problems, have been monitored in Korea since 2014. Measured VOC concentrations can be affected by matrix type and the volatility of target substances. In this study, (1) VOCs volatility and the influence of matrix interference were confirmed, and (2) internal standards (IS) method was applied to improve analytical method. For these purposes, method detection limit (MDL), calibration linearity, precision and accuracy of VOCs were compared in various matrices using the IS. Some of VOCs in sediments showed different peak areas and reduced rates compared to water matrix. It was suggested that adsorption properties of sediments hindered the migration to vapor during heat pretreatment in headspace method. A calibration curve was created in clean sand. Recovery rates for the calibration curve method and IS applying method were 64.1~83.1% and 99.1~119.3%, respectively. Relative standard deviations ranged from 11.1% to 21.6% for the calibration curve method and those for IS ranged 4.7% to 13.7%. In case of real sediment, calibration curve and 1,2-Dichlorobenzene-d4 (ODCB) among IS were not suitable. The average recovery rate of Fluorobenzene (FBZ) increased by 56.4% and Relative Standard Deviation (RSD) by 4.7%. However, the recovery rate was increased in the samples with large values of igniting intensity. This study confirmed that influence of the matrix of VOCs in sediment, and addition of IS materials improved precision and accuracy. Although IS corrects volatilization and adsorption, it is recommended that more than two types of IS should be added rather than single.

• Proceedings of the Korean Society of Crop Science Conference
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• 2019.09a
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• pp.97-97
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• 2019

• Journal of Environmental Science International
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• v.28 no.1
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• pp.7-18
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• 2019

This study aimed to assess the impact of livestock excreta discharged from an Intensive Livestock Farming Area (ILFA) on river water quality during a rainfall event. The Bangcho River, which is one of the 7 tributaries in the Cheongmi River watershed, was the study site. The Cheongmi River watershed is the second largest area for livestock excreta discharge in Korea. Our results clearly showed that, during the rainfall event, the water quality of the Bangcho River was severely deteriorated due to the COD, $NH_4-N$, T-N, $PO_4-P$, T-P, and heavy metals (Cu, Zn, and Mn) in the run-off from nearby farmlands, where the soil comprised composted manure and unmanaged livestock excreta. In addition, stable isotope analysis revealed that most of nitrogen ($NH_4-N$ and $NO_3-N$) in the run-off was from the ammonium and nitrate in the livestock excreta. The values of ${\delta}^{15}N_{NH4}$ and ${\delta}^{15}N_{NO3}$ for the Bangcho River water sample, which was obtained from the downstream of mixing zone for run-off water, were lower than those for the run-off water. This indicates that there were other nitrogen sources upstream river in the river. It was assumed from ${\delta}^{15}N_{NH4}$ and ${\delta}^{15}N_{NO3}$ stable isotope analyses that these other nitrogen sources were naturally occurring soil nitrogen, nitrogen from chemical fertilizers, sewage, and livestock excreta. Therefore, the use of physicochemical characteristics and nitrogen stable isotopes in the water quality impact assessment enabled more effective analysis of nitrogen pollution from an ILFA during rainfall events.