• Korean Journal of Plant Resources
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• v.34 no.6
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• pp.510-516
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• 2021

Whitening agents derived from natural sources which do not have side effects are sought after. Schizophragma hydrangeoides is an edible plant that grows wild on Jeju Island. We aimed to determine whether S. hydrangeoides extracts show anti-melanogenic activity. Here, we found that 70% ethanol extracts of S. hydrangeoides leaf suppressed α-melanocyte-stimulating hormone-induced melanogenesis in B16F10 mouse melanoma cells. This activity of anti-melanogenesis in B16F10 cells were investigated by determining melanin content and tyrosinase activity, and by performing western blotting. The 70% ethanol extract downregulated tyrosinase and tyrosinase-related protein 1. In addition, the n-hexane fraction of S. hydrangeoides leaf (HFSH) exhibited significant anti-melanogenic activity among the various solvent fractions tested without reducing the viability of B16F10 cells. Taken together, these results indicate that extracts from S. hydrangeoides leaf can influence cellular processes via modulation of tyrosinase activity. Hence, S. hydrangeoides can be used as a whitening agent in the cosmetic industry and as a therapeutic agent for treating hyperpigmentation disorders in the clinic.

• Korean Journal of Environmental Biology
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• v.25 no.4
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• pp.336-341
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• 2007

To investigate the variations of physico-chemical factors and microbial population, in ten stations at water region of coastal area of Chagwi-Do, Nutritive salts, water temperature, transparency, suspended solid, salinity, COD, DO, pH, heterotrophic bacteria, were analysed three times in September, November in 2004 and February in 2005. Heterotrophic bacteria in surface water was $3.5\times10^1\sim1.16\times10^3\;cfu\;mL^{-1}$, $0.4\times10^1\sim5.6\times10^1\;cfu\;mL^{-1}$, $0.4\times10^1\sim7.8\times10^1$ and bottom water counted $4.5\times10^1\sim1.0\times10^3\;cfu\;mL^{-1}$, $1.2\times10^1\sim1.5\times10^2\;cfu\;mL^{-1}$, $0.4\times10^1\sim4.4\times10^1\;cfu\;mL^{-1}$ in September, November 2004 and February 2005, respectively. The dominant species isolated from the coastal area of Chagwi-Do were identified to be Vibrio spp., Pseudoalteromonas spp. Psuedomonas spp, Bacillus spp., Alteromonas spp., Aeromonas spp., Psychrobacter spp., and Flavobacterium spp.

• Korean Journal of Veterinary Research
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• v.29 no.3
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• pp.333-342
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• 1989

Effect of raising types and environmental conditions on the infection of Toxoplasma in the swine, the cat and the man were studied in Cheju Island from Sept. 1987 to Aug. 1988. Blood samples were taken from 214 conventionally raised swine in 6 villages and 506 swine raised in swine specialized farms, 122 cats raised under free moving or restraned conditions in 8 locations, 113 butchers, and 210 villagers. Toxoplasma antibody values of the blood sera were determined using the enzymelinked immunosorbent assay (ELISA). The eating type of viscera was also investigated by using questionaires 1. When ELISA method was used, the percentage of Toxoplasma infected swine among the conventionally raised and of those raised in swine specialized farms were 60.7% and 21. 390, respectively. The respective mean of antibody values (${\pm}SD$) were 0.589 (${\pm}0.310$) and 0.385 (${\pm}0.237$) and differed very significantly (p<0.01). A significant difference was also found in antibody values among 6 villages (p<0.05). 2. The mean infection percentage of toxoplasma in the cat was 38.2%. the infection percentage for cats raised under free-moving and re~;trained condition were 37.0% and 38.2% respectively. The respective antibody values(${\pm}SD$) for toxoplasma were 0.600(${\pm}0.614$) and 0.637 (0.645), and did not difference significantly. 3. The infection percentage of toxoplasma in villagers and butchers were 26.2 and 38.3% respectively. The respective antibody values (SD) for toxoplasma were 0.429(${\pm}0.195$) and 0.341 (${\pm}0.236$), and differed very significantly (p<0.01). There were also highly significant differences Pyo-sun and other village (p<0.01). 4. Analysis of the questionaires showed that 26.0% of 392 villages eated liver and some villagers eated other viscera.

• Journal of the Korean Wood Science and Technology
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• v.42 no.6
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• pp.659-665
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• 2014

Wood properties are affected by environmental factors such as soil and climate change. There were close relationships between mechanical properties and stand characteristics for Quercus serrata stands in Gyeongsangnam-do Province, Jeollanam-do Province and Je-ju island. Both compression and shear strengths of woods showed a negative correlation with diameter at breast height (DBH) and the number of tree per hector, while they are positively related with with tree age, altitude, and drainage. The annual ring width was also negatively correlated with tree age, altitude, drainage, DBH, and tree height. However, anatomical characteristics of wood did not show much variation depending on the provincial regions. These results brought a conclusion that Quercus serrata in southern region could be useful forest resources for the utilization of wood.

• Korean Journal of Environmental Biology
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• v.37 no.1
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• pp.88-92
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• 2019

The objective of this study was to report the group mating of Asian Keelback snake, Hebius vibakari, in South Korea. On May 20, 2009, the group mating of H. vibakari was observed in the Maeng-gol do, Jindo-gun, Jeollanam-do, in the rocky area (107 m above sea level) on the ridge of the island. Six female and five male snakes made a form of mating behavior called "mating ball". Two couples showed "tail-wrestling" which is the copulation behavior in snake species. During the mating, the temperature and humidity were $25.7^{\circ}C$ and 59%, respectively. The result of this study was the first case report of the group mating in H. vibakari, a rare reptile.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.1
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• pp.60.3-61
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• 2021

The Korean VLBI Network (KVN) consists of three 21m radio telescopes installed in Seoul, Ulsan, and Jeju Island with the world's first 4-channel receiver that can observe four different frequencies (e.g., 22, 43, 86, 129 GHz) simultaneously. This receiving system of KVN is particularly effective in millimeter-wavelength VLBI (mm-VLBI) observations by compensating fast atmospheric fluctuations effectively. This technology is now being enhanced with a compact triple-band receiver, becoming the world standard for a mm-VLBI system. In 2020, KVN supported 54 observing programs (KVN: 28, EAVN: 26) including the 2nd KVN Key Science Program (KSP) which supports 8Gbps data recording rate and the East Asian VLBI Network (EAVN) programs. KVN also participated in the European VLBI Network (EVN) and GMVA (Global Millimeter VLBI Array) sessions regularly. Here, we report current status and future propsects of KVN.

• Fisheries and Aquatic Sciences
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• v.26 no.9
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• pp.558-568
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• 2023

Vibrio vulnificus is an aquatic bacterium causing septicemia and wound infection in humans. To understand this pathogen at the genomic level, it was performed whole genome sequencing of a cefoxitin-resistant strain, V. vulnificus 1908-10 possessing virulence-related genes (vvhA, viuB, and vcgC) isolated from Gadeok island coastal seawater in South Korea. The genome of V. vulnificus 1908-10 consisted of two circular contigs and no plasmid. The total genome size was estimated to be 5,018,425 bp with a guanine-cytosine (GC) content of 46.9%. We found 119 tRNA and 34 rRNA genes respectively in the genome, along with 4,352 predicted protein sequences. Virulence factor (VF) analysis further revealed that V. vulnificus 1908-10 possess various virulence genes in classes of adherence, antiphagocytosis, chemotaxis and motility, iron uptake, quorum sensing, secretion system, and toxin. In the comparison of the presence/absence of virulence genes, V. vulnificus 1908-10 had fur, hlyU, luxS, ompU, pilA, pilF, rtxA, rtxC, and vvhA. Of the 30 V. vulnificus comparative strains, 80% of the C-genotype strains have all of these genes, whereas 40% of the E-genotype strains have all of them. In particular, pilA were identified in 80% of the C-type strains and 40% of the E-type strains, showing more difference than other genes. Therefore, V. vulnificus 1908-10 had similar VF characteristics to those of type C strains. Multifunctional-autoprocessing repeats-in-toxin (MARTX) toxin of V. vulnificus 1908-10 contained 8 A-type repeats (GXXGXXXXXG), 25 B.1-type repeats (TXVGXGXX), 18 B2-type repeats (GGXGXDXXX), and 7 C-type repeats (GGXGXDXXX). The National Center for Biotechnology Information (NCBI) Basic Local Alignment Search Tool (BLAST) showed that the RtxA protein of V. vulnificus 1908-10 had the effector domain in the order of cross-liking domain (ACD)-C58_PaToxP-like domain- α/β hydrolase-C58_PaToxP-like domain.

• Parasites, Hosts and Diseases
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• v.57 no.6
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• pp.691-698
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• 2019

The seasonal abundance of hard ticks that transmit severe fever with thrombocytopenia syndrome virus was monitored with a collection trap method every April to November during 2015-2018 and with a flagging method every July and August during 2015-2018 in Ganghwa-do (island) of Incheon Metropolitan City, Republic of Korea. This monitoring was performed in a copse, a short grass field, coniferous forest and broad-leaved forest. A total of 17,457 ticks (8,277 larvae, 4,137 nymphs, 3,389 females, and 1,654 males) of the ixodid ticks comprising 3 species (Haemaphysalis longicornis, H. flava, and Ixodes nipponensis) were collected with collection traps. Of the identified ticks, H. longicornis was the most frequently collected ticks (except larval ticks) (94.26%, 8,653/9,180 ticks (nymphs and adults)), followed by H. flava (5.71%, 524/9,180) and Ix. nipponensis (less than 0.04%, 3/9,180). The ticks collected with collecting traps were pooled and assayed for the presence of SFTS virus with negative results. In addition, for monitoring the prevalence of hard ticks, a total of 7,461 ticks (5,529 larvae, 1,272 nymphs, 469 females, and 191 males) of the ixodid ticks comprising 3 species (H. longicornis, H. flava, and Ix. nipponensis) were collected with flagging method. H. longicornis was the highest collected ticks (except larval ticks) (99.53%, 1,908/1,917 ticks (nymphs and adults)), followed by H. flava (1.15%, 22/1,917).

• Journal of Korea Water Resources Association
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• v.47 no.1
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• pp.49-62
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• 2014

As the Urban area grows and more land is developed both within the city and in surrounding areas, hydrologic functions of the natural water cycle are altered. Urbanization creates impervious areas that negatively impact stormwater runoff characteristics. these changes to the natural hydrologic cycle result in the increased flooding, decreased groundwater recharge, increased urban heat island effects. Finally, the land use and other activities result in accumulation and washoff of pollutants from surface, resulting in water quality degradation. Therefore, in this study, evaluating and quantitative analysis of the percolation effect through infiltration experiment of permeable pavement, which is one of the ways that can reduce the problem of the dry stream. Also the SWMM model is used to study the effect of the hydrologic cycle for permeable pavement block contribution.

• Journal of Environmental Science International
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• v.15 no.3
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• pp.271-278
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• 2006

To investigate the variations of physico-chemical factors and microbial population, in ten stations at water region of coastal area of Chagwi-Do, Nutritive salts, water temperature, transparency, suspended solid, salinity, COD, DO, pH, heterotrophic bacteria, coliform group and Vibrio spp. were analysed three times in September, November in 2004 and February in 2005. Heterotrophic bacteria in surface water was $3.5X10^1{\sim}1.16X10^3cfu/ml,\;1.0X10^2{\sim}5.2X10^1cfu/ml\;2.0X10^1{\sim}7.6X10^1cfu/ml$ and bottom water counted $7.0X10^2{\sim}1.0X10^3cfu/ml,\;1.4X10^1{\sim}2.5X10^2cfu/ml\;2.0X10^2{\sim}4.2X10^1cfu/ml$ in September, November in 2004 and February in 2005, respectively. The cell number of total coliform bacteria in the surface water amounted to $0{\sim}4.3X10^2cfu/ml,\;0{\sim}6.0X10^1cfu/ml,\;0{\sim}1.0X10^1cfu/ml$ and bottom water amounted $0{\sim}2.2X10^2cfu/ml,\;0{\sim}5.4X0^2cfu/ml,\;0{\sim}2.0X10^1cfu/ml$ in September, November in 2004 and February in 2005, respectively. As for Vibrio spp., the cell number in the surface water was $1.0X10^1{\sim}2.5X10^2cfu/ml,\;1.0X10^1{\sim}2.0X10^1cfu/ml,\;0cfu/ml$ and bottom water counted $1.0X10^1{\sim}5.2X10^2cfu/ml,\;0cfu/ml,\;2.0X10^1cfu/ml$ in September, November in 2004 and February in 2005, respectively.