• Journal of Microbiology and Biotechnology
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• v.13 no.5
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• pp.666-672
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• 2003

Vacuolar degeneration of the gastric epithelial cells is a characteristic feature of the derangement of mucosa where Helicobacter pylori colonizes, and H. pylori vacuolating cytotoxin (VacA) has been suggested to playa key role in it. To elucidate the VacA-involved degenerative mechanism, VacA was purified, and its impact on degeneration of HeLa cells was determined. In the presence of ammonium chloride, cell vacuolation by VacA was dose-and time-dependent, however, no detectable degeneration of the cells was observed with the VacA concentration tested. A further increase of vacuolation was shown in cells pre-treated with diethyl pyrocarbonate (DEPC) , and this resulted in a change of the cell morphology to become spherical. Similar phenomena were also observed when HeLa cells were co-cultivated with intact H. pylori cells. It was remarkable to note that the degree of growth inhibition was proportional to the increase in vacuole formation, suggesting that the vacuolation rate would be critical for cell degeneration. Surprisingly, although VacA was itself inhibited by DEPC, its uptake was markedly increased by this agent, similar to that found in cells with Nabutyrate. These data indicate that the cell's tolerance of VacA transport may be critical for vacuolar degeneration and may be changeable during H. pylori inhabitation.

• Journal of Wetlands Research
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• v.7 no.4
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• pp.51-65
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• 2005

The insects and Benthic Macro-Invertebrates are very important for index of investigation. This reserch is executed a field investigation with a date analysis of the laboratory under such as above hypothesis and we have grasped the change of the creature according to the season through the executing of field investigation(We executed six times about the insects, seven times about the Benthic Macro-Inbertebrates each expending from Apr. to Oct. 2004). The result of summary in 2004 show that, we have grasped 12 orders 56 familys 116 species on 2001 and 10 orders 42 familys 78 species on 2002 through the investigation. Also we have grasped 13 orders 53 familys 114 species on 2003 and 12 orders 63 familys 121 speceies on 2004 through the investigation. In the case of enthic Macro-Invertebrates, we executed the analysis through the investigation result expending from 2003 to 2004 due to there is no literature investigation record from 2001 to 2002. We have grasped 8 orders 17 familys 24 species on 2003 and 7 orders 11 familys 24 species on Aug. 2004 through the investigation. We executed the analysis about an each condition due to it is difficult to compare the above result simply by the various variable at the investigation. We expect that it become the fundamental reference data to establish a efficient mode of life undo plan after grasped the inhabitation and movement route of creature inside the river through this reserch.

• Korean Journal of Ecology and Environment
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• v.50 no.3
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• pp.325-336
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• 2017

The ecosystem in the Gwangju Stream has taken a wide range of disturbance such as the discharging water of sewage treatment plant, the lake water and the river water from different water system over the past decade. This study was figured out some significant influence factors by analyzing the relationship between biotic and abiotic factors in the urban stream. Abiotic components included 15 water quality variables which were measured in five sampling sites along the stream from October 2014 to July 2015, whereas the benthic macroinvertebrates found in those sites were used to estimate various biotic indices representing the ecological status of the community. The results of correlation analyses indicated that abiotic factors by human activities affected on the inhabitation of benthic macroinvertebrates more than biotic factors. The results of cluster analyses and ANOVA tests also showed that biotic and abiotic characteristics were clearly different in season. The main influence factors of cluster analysis by sites were $NH_3-N$, EPT(I) and DO. It was considered that more various statistical analyses would be necessary to find some different relationships and influence factors between biotic and abiotic variables in the urban stream.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.3
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• pp.232-238
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• 2010

The moving ranges and behavior of four wild abalones, Haliotis discus hannai, were measured by an acoustic telemetry technique. The shape of the sea bottom of the experimental area was surveyed by a bathymetry system and three self-recording type acoustic receivers were used for monitoring the behavior and measuring the movement range. The abalones (WA1-WA4) attached acoustic tags were released and measured the movement during ten months. Three abalones (WA1, WA3 and WA4) were successively detected around the released point during the experiment and were moved to the V2 area where water depth is deeper than the V1 area. The change of inhabitation depth was also detected from the depth sensor of WA4. As the result, abalones were moved to deeper water area accordance with the decrease of the water temperature. The moved ranges of abalones were approximately 200 - 400m from the release point.

• Bulletin of the Society of Naval Architects of Korea
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• v.25 no.2
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• pp.31-43
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• 1988

In recent years increased attention has been directed towards the problems of vibration and noise in superstructure, which have caused major problems with regard to the environmental afterbody of the ship, and the fore-and-after vibration of superstructure due to the vertical vibration of main hull girder is the most important as for the inhabitation of the ship. Accordingly, in this paper, the characteristics of the fore-and after vibration of superstructure and studied systematically with regard to the shape and height of superstructure based on finite element method of beam-like model. The study is divided into two parts, one is the calculation of natural frequencies and the other is the investigation of response at the top of superstructure caused by in its harmonic excitation force at the stern of hull girder. For the natural frequency the calculation results are shown that the higher superstructure is, the lower the natural frequencies of the fore-and-after vibration of superstructure is. It means that the natural frequency of superstructure is close to that of hull girder. The response of vertical direction at the stern of hull girder induced by unit harmonic force is less affected by the shape and the height of superstructure but the response of the fore-and-after direction at the top of superstructure is affected considerably by those of superstructure.

• Korean journal of applied entomology
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• v.30 no.3
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• pp.174-179
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• 1991

Patterns of ginseng damage by larvae of Holotrichia diomphalia Bates in spring were investigated in 3rd year ginseng fields from 1986 to 1990. Ginseng damages were more serious in outer areas than inner areas of ginseng fields, which seemed to be due to nocturnal migration behavior of adult females. Damaged parts of 3rd year ginseng plants due to 3rd instar larvae were top, middle, bottom or whole of main roots, and rarely underground stems. Mean inhabitation depth of 3rd instar larvae were 3.2cm, 5.6cm, 6.6cm and 4.9cm in 1st, 2nd and 3rd year ginseng fields and mugwort fields, respectively. Larval feeding damage of ginseng in spring oc¬curred mainly from mid-May to early July and appeared to decrease temporarily when rainfalls increased.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.6
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• pp.107-115
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• 2010

This study was surveyed to identify changes of flora during three years after restoration in Cheonggyecheon stream. There are four sections in Cheonggyecheon. One and two sections are upper streams and three and four sections are down streams. It was surveyed 328 species in 2006. In 2007 and 2008, 446 and 444 species were found, respectively. This result shows that Cheonggyecheon is unstable initial condition in restored stream ecosystem. Naturalized species were 58 species in 2006 and it was respectively 61 and 63 species in 2007 and 2008. Hazard species of ecosystem were three common species during survey period. In appearance of flora per section, three and four sections constituted by natural sites such as point bars, wide flood plains, riffles and ponds, marshes, etc. were surveyed more species than one and two constructed by concrete materials and narrow flow channel. Recently, as time goes by, introduced species are being increased. And succession has mainly been progressed by one year or binary herbs and perennial herbs. Compared with other restored streams, Cheonggyecheon showed more flora than Yangjaecheon and Anyangcheon. It is judged owing to length of surveyed site, various planted species and area of inhabitation space. To manage restored stream ecosystem, monitoring is essential. Further, because change of vegetation after restoration in Cheonggyecheon is very important, continuous monitoring about Flora and Naturalized species and Hazard species of ecosystem is also very important.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.3 no.1
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• pp.1-6
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• 2022

Among the 13 species of otters in the world, only one Eurasian otter (Lutra lutra) is found in South Korea. In the Korean Peninsula, otter pelts were historically valuable and expensive commodities used for international trade, and otters have long been poached as hunting animals. Recent rapid economic development in South Korea has increased habitat fragmentation and loss, creating a continuing threat to the natural environment. Otters live only in the area of rivers and streams as a family group and are territorial (linear habitat). Due to these limited conditions of otter habitat, the population size of otter is lower than that of onshore mammals. According to recent research, DNA analyses using microsatellite markers have shown that only approximately 7-21 otter individuals inhabit river systems for a length of 50-230 km. Korea's urban streams are associated with many threats that hinder otters from inhabiting them. Many areas around the urban streams are surrounded by high concrete riverbanks, and the risk of roadkill is also high. Nevertheless, ecological restoration projects in the urban rivers will contribute greatly to the stable inhabitation of otters. Detailed otter conservation strategies, such as the elimination of threat factors, improvement of habitat environment, and restoration of food resources and shelter, will provide a positive restoration effect on otter and river ecosystems as well.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.2
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• pp.95-107
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• 2016

The gold-spotted pond frog(Pelophylax chosenicus) classified as an Anura in Amphibia is sharply decreasing due to various changes of habitats environment, and designated as IUCN Red List Threatened species(VU; Vulnerable) internationally and domestic endangered species Class-II; therefore, it's in urgent need of the research on habitats restoration of the gold-spotted pond frog in order to prevent its extinction. This study was carried out to verify the effect after restoration by introducing the inhabitation elements deducted by the literature research and a field survey on the habitats for the gold-spotted pond frog in danger of regional extinction in the urban area of Ansan city, Gyeonggi-do, Korea. Accordingly, the capacity for bio-species was increased by expanding the area of habitats into $11,845m^2$, and securing the place for hibernation and corridors and discharge within the habitats, etc. As a result of the monitoring the number of individuals increased by 9.5 times as the reproductive success rate of the gold-spotted pond frog got higher, and by virtue of improvement in the habitats, biodiversity increased to 183 species(4 species of amphibians and reptiles, 4 species of mammals, 17 species of birds, 53 species of insects(terrestrial/Benthic), 4 species of fish, and 102 species of plants). It might be possible to verify the restoration effect of the habitats through continuous monitoring, and suggest the restoration model on the habitats for continuously survivable the gold-spotted pond frog in the urban area by deducting the matters to be improved.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.1
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• pp.70-82
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• 2000

This is a study to generate a theoretical base for the development of wildlife corridor as a solution to the problems of wildlife population size reduction and declining bio-diversity resulting from the fragmented habitats caused by road constructions. This study seeks to examine and define techniques in very aspect of wildlife corridor including planning, site selection, design and development, and maintenance through an actual application. The results of this study are as follows. 1) The wildlife corridor should be developed in an approach supplementing a landscape ecological approach and a restoration ecological approach bilaterally. To this end, systematic methodology and process are required. 2) It was restored an ecosystem as close as possible go to the forest ecosystem before road development. In addition, in order to allow it to function as an ecological corridor, topography restoration, stream development, and ecological plantation were implemented. 3) The result of monitoring activities that continued for one year since the development confirmed the migration and inhabitation of a number of animals including small mammals. It is judged that it functions as a corridor in fragmented habitats as initially expected. 4) Through continuous monitoring in the future, the effects of corridor development on ecological restoration need to be reviewed in a long-term perspective. There is also a need to develop and refine a comprehensive maintenance plan for wildlife corridors and their surroundings. Based on such study results, actual data on the development of wildlife corridor should be accumulated. In follow-up studies, after continuous monitoring for a long period of time, the effects of wildlife corridor development should be evaluated comprehensively and wildlife corridor applicable to Korea should be standardized by correcting disclosed problems.