• Korean journal of applied entomology
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• v.59 no.1
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• pp.73-78
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• 2020

The fall armyworm, Spodoptera frugiperda (Smith, 1797), originated from tropical and subtropical America is one of sporadic agricultural pests in the world. Since the moth has high migration capacity, it rapidly expanded the world distribution such as Africa in 2016, India in 2018, and East-Asian countries in 2019. In Korea, this species was firstly found at maize fields of Jeju Island, in early June 2019, and subsequently detected at many counties of Jeolla-do and Gyeongsang-do in June and July 2019. The first invaded populations of S. frugiperda in Korea were genetically confirmed as one species, S. frugiperda by using a mitochondrial cytochrome oxidase subunit I (COI) gene, and analyzed to be comprised of two haplotypes (hap-1 and hap-2) each belonging to different clades. Among 31 COI sequences, the hap-1 sequence was predominant, accounting for 93.5%.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.4
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• pp.140-155
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• 2020

This study was conducted to identify the location characteristics of infected farms in the areas where livestock diseases were clustered(southern Gyeonggi-do and Chungcheong-do), analyze the probability of disease occurrence in poultry farms, find out the areas corresponding to the conditions, and use them as the basis for prevention of livestock diseases, selection of discriminatory prevention zones, and establishment of prevention strategies and as the basic data for complementary measures. The increase of one poultry farm within a radius of 3-kilometers increases the risk of HPAI infection by 10.9% compared to the previous situation. The increase of 1m in distance from major roads with two lanes or more reduces the probability of HPAI infection by 0.001% compared to the previous situation. If the distance of the poultry farm located with 15 kilometers from a major migratory bird habitat increases by 15 to 30 kilometers, the chance of infection with HPAI is reduced by 46.0%. And if the distance of the same poultry farm increase by more than 30 kilometers, the chances of HPAI infection are reduced by 88.5%. Based on the results of logistic regression, the predicted probability was generated and the actual area of the location condition with 'more than 15 poultry farms within 3km a radius of, within 1km distance from major roads, and within 30km distance from major migratory birds habitat was determined and the infection rate was measured. It is expected that the results of this study will be used as basic data for preparing the data and supplementary measures when the quarantine authorities establish discriminatory quarantine areas and prevention strategies, such as preventive measures for the target areas and farms, or control of vehicles, by identifying the areas where livestock diseases are likely to occur in the region.

• The Korean Journal of Quaternary Research
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• v.17 no.2
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• pp.75-78
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• 2003

This study is conducted to examine the solar radiation features of landscape in Eastern Mongolia and their space and time distribution characteristics. To many foreigners, the name Mongolia conjures up images of the vast steppes of Central Asia. And, indeed, the extensive grasslands of the steppe make up the heart of Mongolia-geographically and economically. Steppe covers nearly the entire far eastern part of Mongolia, extending west in a narrowing band just south of the Khangai and Khan Khokhii mountains all the way to the Depression of the Great lakes. Eastern Mongolia is recognized as one of the last remaining untouched grassland steppes in the world. Landscape of Eastern Mongolia divided by 19 types that belongs to High Mountain, Middle Mountain and low mountain steppe. Only 5.6% of the total land area is covered by forest. Eastern Mongolian steppe is homeland of migratory rare and endangered birds and about 2.0million freely migrating gazelles. According to Mongolian scientists, there is growing evidence of fundamental changes in the Eastern steppe ecosystems in terms of increasing aridity during the last 70 years. As estimated average annual temperature has increased by approximately 0.7oC, soil moisture, energy supply has been changing. These processes closely interrelated into water and energy cycle of steppe ecosystem.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.5
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• pp.761-772
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• 2020

In order to study about species composition and community structure of fish in the coastal water off Boryeong were investigated from January 2018 to December 2019. A total of 10,863 individuals of 87 species of 44 families were collected. The dominant species were Liparis tanakai accounted for 19.8 percent of the total with Amblychaeturichthys hexanema and Collichthys niveatus accounted for 12.4 percent and 11.0 percent of the total number. A cluster analysis based on the Bray-Curtis similarity revealed that the fish community divided into two groups, According to season. The fish species that appeared summer and autumn were mainly migratory, while the fish species that appeared in spring and winter were mainly resident species. Fish caught by stow net had a high percentage of immature fish. It presented that coastal water off Boryeong is located an important spawning and nursery for fisheries resource.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.6
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• pp.676-685
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• 2003

Seasonal variation of the fishery resource in the shallow waters of Ganghwado tidal flat was investigated using monthly collected samples with a fence net from June 1998 to May 1999. Thirty-six species were found including 27 fish species, 6 crustaceans, and 3 molluscs. Of the fish, Konosirus punctatus, Sardinella zunasi Liza haematocheila and Synechogobius hasta dominated in the number of individuals $(92.1\%)$ and in biomass $(94.5\%).$ A few number of resident species, such as L. haematocheila and S. hasta, were collected only during the cold months. As the water temperature increased in the spring, the adult migratory fish such as K. punctatus and S. zunasi, were collected. In the summer, the juvenile fish recruited in the shallow water showing a peak in fish abundance. The data suggested that they grew until late autumn before moving to deeper waters for over-wintering. The principal component analysis showed that the seasonal variation in species composition was principally determined by water temperature and/or water temperature related factors. The species composition of the fish assemblage in the study area suggested that these species are highly adapted to extreme seasonal temperature variation and high water turbidity.

• Journal of Ecology and Environment
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• v.43 no.4
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• pp.454-461
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• 2019

Background: Ikonnikov's whiskered bat (Myotis ikonnikovi) is found throughout the Korean Peninsula, as well as in Kazakhstan, Russia, Mongolia, China, and Japan. It is small-sized and primarily inhabits old-growth forests. The decrease and fragmentation of habitats due to increased human activity may influence the genetic structure of bat populations. This study was designed to elucidate the population genetic structure of M. ikonnikovi using mitochondrial genes (cytochrome oxidase I and cytochrome b). Results: The results showed that M. ikonnikovi populations from Korea have high genetic diversity. Although genetic differentiation was not detected for the COI gene, strong genetic differentiation of the Cytb gene between Mt. Jeombong and Mt. Jiri populations was observed. Moreover, the results indicated that the gene flow of the maternal lineage may be limited. Conclusions: This study is the first to identify the genetic population structure of M. ikonnikovi. We suggest that conservation of local populations is important for sustaining the genetic diversity of the bat, and comprehensive studies on factors causing habitat fragmentation are required.

• Biomolecules & Therapeutics
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• v.22 no.6
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• pp.540-546
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• 2014

The high mortality rates associated with cancer reflect the metastatic spread of tumor cells from the site of their origin. Metastasis, in fact, is the cause of 90% of cancer deaths. Therefore, considerable effort is being made to inhibit metastasis. In the present study, we screened ketotifen for anti-migratory and anti-invasive activities against MDA-MB-231 breast cancer and HT-1080 fibrosarcoma cancer cells. Cancer cell migration and invasion were measured using multi-well chambers. Additionally, western blots were used to examine the effects of ketotifen on the expressions of CDC42, Rho, Rac, and matrix metalloproteinase 9 (MMP-9). The results showed that ketotifen dose-dependently suppressed the migration and invasion of MDA-MB-231 and HT-1080 cells. Ketotifen also suppressed the expressions of CDC42, Rac, and Rho, which, significantly, are involved in MDA-MB-231 and HT-1080 cancer cell migration. Moreover, ketotifen suppressed the expression and activity of MMP-9, which is involved in degradation of the extracellular matrix leading to invasion. The overall data suggested that ketotifen suppresses the migration and invasion of MDA-MB-231 and HT-1080 cancer cells via inhibition of CDC42, Rac, Rho, and MMP-9 expression.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.1
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• pp.14-28
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• 2007

This study presented the selection of ozone ($O_3$) potential factors and designed and assessed its potential prediction model using multiple-linear regression equations in Ulsan area during the springtime from April to June, $2000{\sim}2004$. $O_3$ potential factors were selected by analyzing the relationship between meterological parameters and surface $O_3$ concentrations. In addition, cluster analysis (e.g., average linkage and K-means clustering techniques) was performed to identify three major synoptic patterns (e.g., $P1{\sim}P3$) for an $O_3$ potential prediction model. P1 is characterized by a presence of a low-pressure system over northeastern Korea, the Ulsan was influenced by the northwesterly synoptic flow leading to a retarded sea breeze development. P2 is characterized by a weakening high-pressure system over Korea, and P3 is clearly associated with a migratory anticyclone. The stepwise linear regression was performed to develop models for prediction of the highest 1-h $O_3$ occurring in the Ulsan. The results of the models were rather satisfactory, and the high $O_3$ simulation accuracy for $P1{\sim}P3$ synoptic patterns was found to be 79, 85, and 95%, respectively ($2000{\sim}2004$). The $O_3$ potential prediction model for $P1{\sim}P3$ using the predicted meteorological data in 2005 showed good high $O_3$ prediction performance with 78, 75, and 70%, respectively. Therefore the regression models can be a useful tool for forecasting of local $O_3$ concentration.

• Korean Journal of Ecology and Environment
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• v.55 no.1
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• pp.35-48
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• 2022

Fish assemblage of total 325 of Korean peninsula estuaries were surveyed to analyze the characteristics of community structure and diversity by sea areas for three years from 2016 to 2018. The scale (stream width) of Korean estuaries were various (14~3,356 m), and 68.9% of all estuaries showed salinity of less than 2 psu. Total 149 species classified into 52 families of fish were identified, and the dominant and sub-dominant species were Tribolodon hakonensis (relative abundance, RA, 12.5%) and Mugil cephalus (RA, 9.5%), respectively. The estuary of the Korean Peninsula had different physical and chemical habitat environments depending on the sea area, and accordingly, fish community structure also showed statistically significant differences (PERMANOVA, Pseudo-F=26.69, P=0.001). In addition, the NMDS (nonmetric multidimensional scaling) results showed the patterns that indicating fish community difference by sea areas, even though low community similarity within sea area (SIMPER, 21.79~26.39%). The estuaries of east sea areas were distinguished from the others in the aspects of which, the higher importance of migratory fishes and endangered species, and that of brackish species were characterized at south sea estuaries. However, the estuaries of west sea showed higher importance of species that have a relation with freshwater (primary freshwater species, exotic species), which is the result that associating with the lower salinity of west sea estuaries because of the high ratio of closed estuaries(78.2%). The SIMPER analysis, scoring the contribution rates of species to community similarity, also showed results corresponding to the tendency of different fish community structures according to each sea area. So far, In Korea, most studies on fish communities in estuaries have been conducted in a single estuary unit, which made it difficult to understand the characteristics of estuaries at the national level, which are prerequisite for policy establishment. In present study, we are providing fish community structure characteristics of Korean estuaries in a national scale, including diversity index, habitat salinity ranges of major species, distribution of migratory species. We are expecting that our results could be utilized as baseline information for establishing management policies or further study of Korean estuaries.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.15 no.2
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• pp.72-85
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• 2010

Seasonal variation in species composition of estuarine fauna in the Han River estuary was determined using monthly samples collected near Ganghwa Island by a bag net from February to December 2009. Total number of species was 86: 54 species of fishes, 16 species of shrimps of crustacean, 12 species of other crustacean such as craps and so on, 3 species of cephalopods and 1 species of jellyfish. Of a total of 86 species, Palaeman carinicauda (32.6%), Acetes japonicus (15.9%), Palaemon gravieri (9.9%), Portunus trituberculatus (7.7%) and Acetes chinensis (6.9%) were predominated in abundance. These 5 crustacean accounted for 73% of total. Abundance, biomass and diversity of Han River estuarine fauna were high in spring and autumn, indicating typical pattern of temperate area. Out of dominant species, the brackish residence species such as Coilia nasus, Chelon haematocheilus, Mugil cephalus, Synechogobius hasta, Lophiogobius ocellicauda, Tridentiger barbatus, Palaeman carinicauda, Palaemon gravieri were collected almost year-round and predominated in abundance. Coastal migratory fauna species such as Coilia mystus, Thryssa hamiltonii, Thryssa adelae, Sardinella zunasi, Engraulis japonicus, Portunus trituberculatus, Acetes japonicus, Collichthys lucidus, Pampus argenteus were most plentiful from spring through autumn. Their adult coastal migratory entered the estuary in spring and large numbers of their juveniles were grew in summer and autumn until moving out to deeper waters for over-wintering, indicating they use estuary as nursing ground. Diadromous fish such as Anguila japonica adults were collected in autumn during their downstream migration. Brackish fauna and crustacean, especially shrimps were predominant, and few contaminant indicator species collected in the Han River estuary, indicating this area maintains the characteristics of natural estuary ecosystem.