• Journal of Life Science
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• v.33 no.12
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• pp.1002-1014
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• 2023

The root of Cirsium japonicum var. maackii (Maxim.) has long been used in traditional medicine to prevent the onset and progression of various diseases and has been reported to exert a wide range of physiological effects, including antioxidant activity. However, research on its effects on hepatocytes remains scarce. This study used the human hepatocellular carcinoma HepG2 cell line to investigate the antioxidant activity of ethanol extract of C. japonicum root (EECJ) on hepatocytes. Hydrogen peroxide (H₂O₂) was used to mimic oxidative stress. The results showed that EECJ significantly reverted the decrease in cell viability and suppressed the release of lactate dehydrogenase in HepG2 cells treated with H₂O₂. Moreover, an analysis of changes in cell morphology, flow cytometry, and microtubule-associated protein light chain 3 (LC3) expression showed that EECJ significantly inhibited HepG2 cell autophagy induced by H₂O₂. Furthermore, it attenuated H₂O₂-induced apoptosis and cell cycle disruption by blocking intracellular reactive oxygen species and mitochondrial superoxide production, indicating strong antioxidant activity. EECJ also restored the decreased levels of intracellular glutathione (GSH) and enhanced the expression and activity of superoxide dismutase and GSH peroxidase in H₂O₂-treated HepG2 cells. Although an analysis of the components contained in EECJ and in vivo validation using animal models are needed, these findings indicate that EECJ is a promising candidate for the prevention and treatment of oxidative stress-induced liver cell damage.

• Journal of Korean Society of Forest Science
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• v.101 no.3
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• pp.333-343
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• 2012

In-stream large wood (LW) has a critical impact on the geomorphic characteristics relevant to ecosystem management and disaster prevention, yet relatively little is known about variations in its dynamics and subsequent export on the watershed-scale perspective in Korea. Here we review variations in the dynamics and subsequent export of LW as a function of stream size, which is appropriate for Korean mountain streams. In upstream channels with narrow bankfull widths and low stream discharges, a massive amount of LW, resulting from forest dynamics and hillslope processes, may persist for several decades on valley floor. These pieces, however, are eventually transported during infrequent debris flows from small tributaries, as well as peak hydrology in main-stem channels. During the transport, these pieces suffer fragmentation caused by frictions with boulders, and stream bank and bed. Although infrequent, these events can be dominant processes in the export of significant amounts of LW from upstream channel networks. In downstream channels with wide bankfull widths and high stream discharges, LW is dominantly recruited by forest dynamics and bank erosion only at locations where the channel is adjacent to mature riparian forests. With the LW pieces that are supplied from the upstream, these pieces are continuously transported downstream during rainfall events. This leads to further fragmentation of the LW pieces, which increases their transportability. With decreasing stream-bed slope, these floated LW pieces, however, can be stored and form logjams at various depositional sites, which were developed by interaction between channel forms and floodplains. These pieces may decay for decades and be subsequently transported as particulate or dissolved organic materials, resulting in the limitation of LW fluvial export from the systems. However, in Korea, such depositional sites were developed in the extremely limited streams with a large dimension and no flood history for decades, and thus it does not be expected that the reduction of LW export amount, which can be caused by the long-term storage. Our review presents a generalized view of LW processing and is relevant to ecosystem management and disaster prevention for Korean mountain streams.

• Journal of Dairy Science and Biotechnology
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• v.34 no.1
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• pp.21-35
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• 2016

Recently, there has been a rapid increase in the sale and purchase of an array of organic products. In particular, organic milk has grown in popularity. This growth could lead to expensive, premium retail prices for various organic cow's milk products. In fact, most consumers believe that (1) dairy farming to produce organic milk is beneficial for human health and (2) organic milk products are made without the use of various antibiotics, synthetic chemicals, genetic modification, extra hormones, and so on. Several factors, including breed, diet, and stage of lactation, are known to influence the composition of milk. Therefore, this review (1) presents a research outline to compare organic and conventional milk and (2) provides a summary of individual elements that affect the composition of milk.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.31 no.3
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• pp.54-60
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• 2013

This study carried out a phytosociological research by Z.-M. school's method describing vegetation structure and management solution about nutmeg tree's(Torreya nucifera ) forests. The nutmeg tree's forests have developed intervale and hills in warm-temperate evergreen broad-leaved forests zone. The nutmeg tree's forests composed 50 familly, 80 genus, 88 species divided two syntaxa(typical sub-community, Arachniodes aristata sub-community) by species composition and correspond to habitat condition. The nutmeg tree's forests show a uniform forest's structure which composed 3~4 layer of sub-tree and shrub. And it was worthy of special mention which characterized diagnostic species of Camellietea japonicae in the warm-temperate evergreen broad-leaved forests. In case of forests floor, were a high rate in order of Ophiopogon japonicus, Polystichum tripteron, Arisaema ringens. And Oplismenus undulatifolius which represent mantle communities as well. This indicates that the nutmeg tree's forests are exposed by humman effects sustainedly. The nutmeg tree's young trees appeared a high rate at half shade and shade. The vigorous tree species have to spacing cutting instead of the heavy thinning that consist in with a shout of declining astructur and function of the forest ecosystem for maintaining a nutmeg tree's forests. And we suggest for the density regulation of the sub-tree and shrub. In conclusion, need to the continuous monitoring about the vegetation structure and management solution for the sustainable nutmeg tree's forests.

• Journal of Digital Convergence
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• v.18 no.6
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• pp.9-16
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• 2020

The purpose of this study is to understand the public needs for AI education actively promoted and supported by the current government. In doing so, 11 metropolitan news articles and Twitter posts regarding AI education that have been posted from January 1, 2018 to December 31, 2019 were collected. Then, word frequency analysis using TF(Term Frequency) method and LDA(Latent Dirichlet Allocation) method of topic modeling analysis were conducted. The topics of the news articles turn out to be a macroscopic policy support such as 'training female manpower in the AI field' and 'curriculum reform of university and K-12', whereas the topics of twitter delineate more detailed social perception on future society, such as future competencies and pedagogical methods, including 'coexistence with intelligent robots', 'coding education', and 'humane education competence development'. The findings are expected to be used to suggest the implications for the composition and management of AI curriculum as well as the basic framework of human resources development in the future industry.

• Journal of Korean Society of Forest Science
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• v.81 no.4
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• pp.325-336
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• 1992

The successional status and potential natural vegetation were examined in a mixed broadleaved-Abies forest located at Mt, Odae National Park. The examination was based on the subsequent process of generation replacement by understory saplings for the dominant canopy trees within 88 $5m{\times}50m$ belt transects. The transition matrix model, which was modified from mathematical theory of Markov chain, was employed to analyze the successional status of the study forest. The model suggests that the study forest is still seral, and it is considered to be more than 700 years away from the steady state or climax in terms of species composition. The simulations predict a remarkable decrease in the proportion of species composition of the present dominant Quercus mongolica and Tilia amurensi.s from current 28% and 13% to less than 3% and 5%, respectively, at the steady state. On the contrary, the proportions of Abies holophylla, Acer pseudo-sieboldianum, Carpinus cordata, and Pinus koraiensis will increase at the steady state. The ratio of mixture between deciduous and coniferous trees will be gradually changed from current 6.5 : 3.5 to 5.0 : 5.0 at equilibrium. Discussion for the problems of Quercus mongolica in successional status noted that the species behaved as a mid-successional dominant, not a climax species in the study forest. The hypothesis and sensitivity of the transition matrix model were also discussed to evaluate the applicability to the real situation. The overall results indicated that the present dynamics of the forest must reflect the seral state due to previous disturbance mainly by hyman related interference.

• Journal of Korea Foresty Energy
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• v.22 no.3
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• pp.1-10
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• 2003

The successional status and potential natural vegetation were examined in the natural deciduous forest in Mt. Chombong area. The examination was based on the subsequent process of generation replacement by understory saplings for the dominant canopy trees within 106 20mx20m square sample plots. The transition matrix model, which was modified from mathematical theory of Markov chain, was employed to analyze the successional status of the study forest. The model suggests that study forest is still seral, and it is considered to be more than 500 years away from the steady state or climax in terms of species composition. The simulations predict a remarkable decrease in the proportion of species composition of the present dominant Quercus mongolica and Kalopanax pictus from current 42.6% and 8.1% to less than 13.3% and 0.5%, respectively, at the steady state. On the contrary, the proportions of Abies holophylla, Acer mono, Fraxinus mandshurica, Tilia amurensis, and Acer pseudo-sieboldianum will increase at the steady state. The change of predicted composition ratio was generally coincide with the result of tolerance index to be compared with the study model. The hypothesis and sensitivity of the model were also discussed to evaluate the applicability to the real situation. The overall results indicated that the present dynamics of the forest must reflect the seral state due to previous disturbance mainly by human related interference.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.4
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• pp.257-266
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• 2008

PAHs are of mainly anthropogenic origin from urban runoff, oil spill and combustion of fossil fuels. Some PAHs are potentially carcinogenic and mutagenic to aquatic organisms. This study was carried out to survey the contamination of PAHs in the column sediments around Gwangyang bay. Yeosu petrochemical industrial complex, POSCO(Pohang steel compony) and Gwangyang container harbor are located near the bay. The column sediments were collected at 4 stations(A, B, C and D) and fractionated at intervals of two-centimeter depth on July 29, 1999. PAHs in colmn sediment samples were extracted in soxhlet extractor and were identified and quantified by GC-MS. PAHs compounds were analyzed and found to be 13 species. Total PAHs concentrations in the column sediments ranged from 275.04 to 2,838.64${\mu}g/kg$ dry wt. Naphthalene had the highest concentration in the range of 40.60 to 2,294.06${\mu}g/kg$ dry wt. and Anthracene had the lowest concentration in the range of 2.63 to 11.30${\mu}g/kg$ dry wt. The correlation coefficients between individual PAHs and total PAHs in the column sediments were relatively higher in the low molecular compounds such as Naphthalene, Acenaphthylene and Phenanthrene. The relationship between the P/A(Phenanthrene/Anthracene)ratio and F/P(Fluoranthene/Pyrene)ratio showed that P/A ratio was generally above 10 and F/P ratio was above 1 in all sediment samples. These data indicate that PAHs in the column sediments around Gwangyang bay seem to be of both pyrolytic and petrogenic origin The values of PAHs in the column sediments were lower than the biological effect guidelines.

• Journal of Climate Change Research
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• v.2 no.1
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• pp.15-32
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• 2011

Due to greenhouse gas increased by human activities, abnormal climate changes are continuously occurring everywhere in the world and internationally people make efforts to reduce the emission of greenhouse gas. Our country also is making endeavors to realize low carbon society on the foundation of the green growth and for this low carbon consumption pattern settlement through green life is necessary. Therefore for the nationals the offering of the information on greenhouse gas emission that is reduced through the change to low carbon life is required. In this study the objects are beef and wine whose weight of import is high among the beverages and foods consumed in the country and we calculated the food mileage and emission of carbon dioxide of the domestic and foreign product beef and wine and estimated the potential amount that can be reduced when replacing the imported products with domestic products. As the year 2007 being standard if we replace 10% of imported beef with domestic products it is possible to reduce 14,000 tons of carbon dioxide per year and on one day out of a year if we replace imported beef with domestic beef the reduction of 384 tons of carbon dioxide is appeared to be possible. In the same standard year if we replace 10% of imported wine with domestic product we can reduce 1,396 tons and on one day out of a year if we replace imported wine with domestic wine reduction of 38 tons of carbon per year appeared to be possible. Through active promotion and expansion of variety of domestic foods and beverages in the real life of the nationals the consumption pattern of natural low carbon life should be achieved and offering of more systematized greenhouse gas emission DB is thought to be necessary.

• Korean Journal of Environmental Agriculture
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• v.26 no.1
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• pp.62-68
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• 2007

Concerns about endocrine disrupting chemicals emitted from humans and animals have been increased because these compounds are detected at very low levels in environment and adversely affect on indigenous fauna. To date, there is little information regarding the concentration of these compounds in animal wastes. In this study, the female hormones, $17\beta-estradiol$ (E2), estrone (E1) and estriol, were measured to provide baseline data in animal wastes. Samples were collected from animal waste storage, methane digester and sludge separated wastewater and analyzed by gas chromatography-mass spectrometry. To measure the mass ratios of estrogen to macronutrients, nitrogen and phosphorous were also determined. Sample collected from animal waste storage had the highest estrogen concentration (98.7 ${\mu}g/L$), while sludge separated wastewater had the lowest concentration (3.4 ${\mu}g/L$). The mean concentrations of E2 and E1 in waste storage sample were (6.8 ${\mu}g/L$) and (68.7 ${\mu}g/L$), respectively. In sludge separated wastewater, the mean concentration of both E2 and E1 were reduced to (2.6 ${\mu}g/L$) and (1.9 ${\mu}g/L$), respectively. However, estriol was not detected in any of the samples collected. Mean ratios of E2 and E1 to macronutrients were significantly different between the methane wastewater and sludge separated wastewater owing to elimination of solid particles.