• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.2
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• pp.11-22
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• 2017

To successfully create a low-carbon landscape in order to become a low-carbon city, it is necessary to understand the dynamics of artificial greening's resources on a multi-scale. Additionally, the effects of carbon storage should be quantitatively evaluated. The purpose of this study is to simulate and evaluate the changes in carbon storages of artificial ground trees using system dynamics throughout a long-term period. The process consisted of analyzing the dynamics of the multi-scale carbon cycle by using a casual loop diagram as well as simulating carbon storage changes in the green roof of the Gangnam-gu office building in 2008, 2018, 2028, and 2038. Results of the study are as follows. First, the causal loop diagram representing the relationship between the carbon storage of the artificial ground trees and the urban carbon cycle demonstrates that the carbon storage of the trees possess mutual cross-scale dynamics. Second, the main variables for the simulation model collected 'Biomass,' 'Carbon storage,' 'Dead organic matter,' and 'Carbon absorption,'and validated a high coefficient of determination, the value being ($R^2$=0.725, p<0.05). Third, as a result of the simulation model, we found that the variation in ranking of tree species was changing over time. This study also suggested the specific species of tree-such as Acer palmatum var. amoenum, Pinus densiflora, and Betula platyphylla-are used to improve the carbon storage in the green roof of the Gangnam-gu office building. This study can help contribute to developing quantitative and scientific criteria when designing, managing, and developing programs on low-carbon landscapes.

• Journal of Korea Water Resources Association
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• v.37 no.10
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• pp.857-868
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• 2004

Since the self-purification capacity of rivers in Korea is significantly controlled by environmental maintenance flow supplied by upstream reservoirs during drought season, it is obviously important to operate the river and reservoir systems considering not only water quantity aspect but also conservation of downstream water quality and ecosystem. In this study, an unsteady river water quality model KORIVl- WIN was developed as a tool for evaluating the impact. of reservoir operations on the downstream water quality. The model parameters were calibrated and verified using field data obtained in Geum River on September and October of 2002, respectively. Intensive data sampling was performed on November 22, 2003 to investigate the effect of a short-term flushing discharge of Daecheong Reservoir, which increased outflow from 30 $m^3$/s to 200 $m^3$/s for 6 hours, on downstream water quality. The model performance was evaluated by comparing simulated results with observed data including hydraulics, biochemical oxygen demand(BOD$_{5}$), nitrogen and phosphorus species during the flushing event. It showed very good performance in predicting the travel time of flushing flow and water quality variations of dissolved forms of nitrogen and phosphorus species, while revealed large deviations for BOD$_{5}$ possibly due to missing the effect of organic matters resuspension from river bottom sediment during the wave front passage.

• ALGAE
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• v.35 no.1
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• pp.45-59
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• 2020

To investigate the spatio-temporal distributions of the mixotrophic dinoflagellate Yihiella yeosuensis in Korean coastal waters and its grazing impact on prey populations, water samples were seasonally collected from 28 stations in the East, West, and South Seas of Korea and Jeju Island from April 2015 to October 2018. The abundances of Y. yeosuensis in the water samples were quantified using quantitative real-time polymerase chain reaction (qPCR). Simultaneously, the physical and chemical properties of water from all sampled stations were determined, and the abundances of the optimal prey species of Y. yeosuensis, the prasinophyte Pyramimonas sp. and the cryptophyte Teleaulax amphioxeia, were quantified using qPCR. Y. yeosuensis has a wide distribution, as is reflected by the detection of Y. yeosuensis cells at 23 sampling stations; however, this distribution has a strong seasonality, which is indicated by its detection at 22 stations in summer but only one station in winter. The abundance of Y. yeosuensis was significantly and positively correlated with those of Pyramimonas sp. and T. amphioxeia, as well as with water temperature. The highest abundance of Y. yeosuensis was 48.5 cells mL^-1 in Buan in July 2017, when the abundances of Pyramimonas sp. and T. amphioxeia were 917.6 and 210.4 cells mL^-1, respectively. The growth rate of Y. yeosuensis on Pyramimonas sp., calculated by interpolating the growth rates at the same abundance, was 0.49 d^-1, which is 37% of the maximum growth rate of Y. yeosuensis on Pyramimonas sp. obtained in the laboratory. Therefore, the field abundance of Pyramimonas sp. obtained in the present study can support a moderate positive growth of Y. yeosuensis. The maximum grazing coefficient for Y. yeosuensis on the co-occurring Pyramimonas sp. was 0.42 d^-1, indicating that 35% of the Pyramimonas sp. population were consumed in 1 d. Therefore, the spatio-temporal distribution of Y. yeosuensis in Korean coastal waters may be affected by those of the optimal prey species and water temperature. Moreover, Y. yeosuensis may potentially have considerable grazing impacts on populations of Pyramimonas sp.

• Molecules and Cells
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• v.40 no.2
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• pp.100-108
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• 2017

Cathepsin F, which is encoded by CTSF, is a cysteine proteinase ubiquitously expressed in several tissues. In a previous study, novel transcripts of the CTSF gene were identified in the crab-eating monkey deriving from the integration of an Alu element-AluYRa1. The occurrence of AluYRa1-derived alternative transcripts and the mechanism of exonization events in the CTSF gene of human, rhesus monkey, and crabeating monkey were investigated using PCR and reverse transcription PCR on the genomic DNA and cDNA isolated from several tissues. Results demonstrated that AluYRa1 was only integrated into the genome of Macaca species and this lineage-specific integration led to exonization events by producing a conserved 3' splice site. Six transcript variants (V1-V6) were generated by alternative splicing (AS) events, including intron retention and alternative 5' splice sites in the 5' and 3' flanking regions of CTSF_AluYRa1. Among them, V3-V5 transcripts were ubiquitously expressed in all tissues of rhesus monkey and crab-eating monkey, whereas AluYRa1-exonized V1 was dominantly expressed in the testis of the crab-eating monkey, and V2 was only expressed in the testis of the two monkeys. These five transcript variants also had different amino acid sequences in the C-terminal region of CTSF, as compared to reference sequences. Thus, species-specific Alu-derived exonization by lineage-specific integration of Alu elements and AS events seems to have played an important role during primate evolution by producing transcript variants and gene diversification.

• Journal of fish pathology
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• v.13 no.2
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• pp.137-142
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• 2000

Differences in larvicidal activity of complement and chemiluminescent response of phagocytes in carp (Cyprinus carpio), crucian carp (Carassius auratus) and false dace (Pseudorasbora parva) against excysted metacercariae of Clonorchis sinensis were investigated. The prevalence of C. sinensis metacercariae of false daces caught at Nakdong river (NR) was 100%. However, no C. sinensis metacercariae were found in false daces, which were collected at a reservoir in Chinyoung (CY), crucian carps and carps. The sera of false dace, which were intensively infected with C. sinensis metacercariae, killed excysted metacercariae of C. sinensis more readily than that of carp. However, the serum obtained from C. sinensis metacercariae-free false dace showed the lowest larvicidal ability. The larvicidal ability of sera collected from each fish species completely disappeared when the complement was inactivated by heating. When supernatant of excysted metacercariae homogenate were added to phagocytes of each species, the chemiluminescent responses were significantly (p<0.05) diminished in false dace and carp. The inhibition ratio of chemiluminescent responses by the supernatant was 22.9% in false dace, 9.6% in crucian carp and 12.4% in carp.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.4
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• pp.451-458
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• 2018

The coast of Incheon reaches Incheon itself, Gimpo, Siheung, and Ansan of Gyunggi-do. Because this area has been seriously polluted, the Ministry of Oceans and Fisheries has established the Incheon Special Area Management Plan (SAMP) to preserve sea water quality as a marine environment asset. However, there is concern that actions taken in this area may change the surrounding marine ecology, being effected by farms, via a river that flows from waste lands, abandoned fishing activities and fishing nets, etc. Given this background, this study estimates the value of SAMP sea water quality using a choice experiment (CE). A CE survey of 1,000 households was undertaken, investigating trade-offs involving price and four attributes for selecting a preferred alternative to obtain a marginal willingness to pay (MWTP) estimate for each attribute. The estimation results showed that MWTP for a 1 %p improvement in sea water quality, the diversity of fauna species, the diversity of flora species, and a 1 %p reduction in marine litter as a result of conserving Incheon coastal sea water quality are estimated to be KRW 75, 135, 309 and 72 per household per year, respectively. All estimation results were statistically significant at the 1 % level. These findings can provide policy makers with useful information for evaluating and planning marine environmental management policies.

• Journal of Food Hygiene and Safety
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• v.36 no.5
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• pp.407-417
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• 2021

In order to investigate frequency of fungal contamination in ginseng sprout, we collected 18 types of retail ginseng sprouts and analyzed them. Overall frequency of fungal contamination ranged from 113.3 to 174.1% with the highest occurrence of Penicillium spp. Fungal detection rate was significantly higher in moss than in stem, leaf and root of ginseng sprout. Penicillium spp. occurred in leaf and stem with the highest incidence and Fusarium spp., in root. Among Penicillium spp. and Fusarium spp., P. olsonii and F. oxysporum were dominant, respectively. Nine Fusarium species, Aspergillus westerdijkiae, Aspergillus flavus, and 11 Penicillium species were identified by phylogenetic analysis. PCR screening of mycotoxigenic potential revealed that 19 out of 25 isolates tested were positive for respective mycotoxin biosynthetic gene. Two 2 A. flavus and 11 A. westerdijkiae isolates produced varying amount of aflatoxin or ochratoxin A in czapek yeast extract brothsome of which showed high levels of mycotoxin production. These results suggests a need for continuous monitoring and management program to control fungal contamination in the ginseng sprout production chain.

• Journal of Food Hygiene and Safety
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• v.34 no.3
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• pp.303-308
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• 2019

L-carnitine is found in high levels in muscle tissues. It has been developed as a nutrient and dietary supplement, and also used as a therapeutic supplement in various diseases including type II diabetes, osteoporosis and metabolic neuropathies. However, it is not fully understood how it affects cellular mechanisms in colorectal cancer. Therefore, we attempted to determine the effect of L-carnitine in HCT116 human colorectal cancer cells. First, the HCT116 cells were exposed to L-carnitine for 24 hours at 0-40 mM, and then analyzed for cellular proliferation, oxidative stress and related mechanisms. In a MTT assay, L-carnitine inhibited cellular proliferation and induced reactive oxygen species (ROS) in HCT116 by DCF-DA analysis. To analyze the mechanism of L-carnitine in colorectal cancer cells, we performed a western blot analysis for pERK1/2 and pp38 MAP kinase. The western blot showed that L-carnitine significantly increased protein levels of pERK1/2 and pp38 compared with control. Taken together, we found that L-carnitine has anti-proliferative function via increased ROS and activation of ERK1/2 and p38 pathway in HCT116. These findings suggest that L-carnitine may have an anti-proliferative role on colorectal cancer.

• Journal of Life Science
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• v.31 no.3
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• pp.338-345
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• 2021

Zizania latifolia has long been used as a tea for both edible and medicinal purposes. However, research into the use of Z. latifolia as a high value-added edible material is lacking. In a previous study, we confirmed that tricin is the major component in Z. latifolia. In this study, we investigated the protective effect of a Z. latifolia extract (ZLE). Toxicity tests of ZLE or tricin on HepG2 cells revealed no toxicity due to ZLE or tricin at all concentrations used. The reduction in cell viability by tert-butyl hydroperoxide (t-BHP) was suppressed by treatment with ZLE or tricin. In addition, ZLE or tricin effectively inhibited the production of reactive oxygen species (generation of hydrogen peroxide, alkoxy free radicals, and peroxyl free radicals by t-BHP) and oxidative damage. ZLE or tricin treatments also increased the protein expression of superoxide dismutase 1 (SOD1), catalase, heme oxygenase-1 (HO-1), and nuclear factor erythroid-related factor 2 (Nrf2), which are known as antioxidant enzymes, suggesting that the protective effect of ZLE is related to activation of tricin. Taken together, the results indicate that Z. latifolia can be developed as a functional food material for improving liver function.

• Bulletin of the Korean Chemical Society
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• v.15 no.3
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• pp.236-241
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• 1994

The crystal structures of $Cd_6-A$ evacuated at $2{\times}10^{-6}$ Torr and 750$^{\circ}$C (a=12.216(l) ${\AA}$), and of the product of its reaction with Rb vapor (a= 12.187(l) ${\AA}$), have been determined by single-crystal x-ray diffraction techniques in the cubic space group Pm$\bar{3}$m at 21(l)$^{\circ}$C. Their structures were refined to the final error indices, $R_1$=0.055 and $R_2$=0.067 with 191 reflections, and $R_1$=0.066 and $R_2$=0.049 with 90 reflections, respectively, for which I>3${\sigma}$(I). In dehydrated $Cd_6-A$, six $Cd^{2+}$ ions are found at two different threefold-axis sites near six-oxygen ring centers. Four $Cd^{2+}$ ions are recessed 0.50 ${\AA}$ into the sodalite cavity from the (111) plane at O(3), and the other two extend 0.28 ${\AA}$ into the large cavity from this plane. Treatment at 250 $^{\circ}$C with 0.1 Torr of Rb vapor reduces all $Cd^{2+}$ ions to give $Rb_{13.5^-}$A. Rb species are found at three crystallographic sites: three $Rb^+$ ions lie at eight-oxygen-ring centers, filling that position, and ca. 10.5 $Rb^+$ ions lie on threefold axes, 8.0 in the large cavity and 2.5 in the sodalite cavity. In this structure, ca. 1.5 Rb species more than the 12 $Rb^+$ ions needed to balance the anionic charge of zeolite framework are found, indicating that sorption of $Rb^0$ has occurred. The occupancies observed can be most simply explained by two "unit cell" compositions, $Rb_{12^-}A{\cdot}Rb$ and $Rb_{12^-}A{\cdot}2Rb$, of approximately equal population. In sodalite cavities, $Rb_{12^-}A{\cdot}Rb$ would have a $(Rb_2)^+$ cluster and $Rb_{12^-}A{\cdot}2Rb$ would have a triangular $(Rb_3)^+$ cluster. Each of the atoms of these clusters must bind further through a six-oxygen ring to a large cavity $Rb^+$ to give $(Rb_4)^{3+}$ (linear) and $(Rb_6)^{4+}$ (trigonal). Other unit-cell compositions and other cationic cluster compositions such as $(Rb_8)^{n+}$ may exist.