• Environmental Analysis Health and Toxicology
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• 제22권3호
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• pp.189-196
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• 2007

[ $TiO_2$ ] is widely used because it is non-toxic. Recently, however, nanometer size $TiO_2$ particles (P-25) have been produced and used to increase the photo catalysis efficiency. Nanometer-sized $TiO_2$ is efficient, but due to its small size ($20{\sim}30\;nm$), it can flow into ecosystems and into cells. Thus, it may affect human health. Additionally, $TiO_2$ can produce a second contaminant, OH-radical, which is a health risk for all living organisms during photo degradation reaction. Hence, when nanometer-sized $TiO_2$ flows into natural streams and attaches to living organisms, it will create health risks. We investigated the biological toxicity of this condition in zebrafish embryos. We observed abnormal morphology, hatching rate, and measured the catalase activity to determine anti-oxidation at 100 post fertilization hours. Zebrafish were somewhat affected by $TiO_2$ nanometer sized particles under UV-A (a condition similar to sunlight). Powdered $TiO_2$ is toxic to the zebrafish fly. Even without light, $TiO_2$ particles attached to embryos and flies, having an effect on both.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권3호
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• pp.56-65
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• 2014

Contamination of explosive compounds in the soils of military shooting range may pose risks to human and ecosystems. As shooting ranges are located at remote places, active remediation processes with hardwares and equipments are less practical to implement than natural solutions such as bioremediaton. In this study, a series of experiments was conducted to select a suitable carbon source and to optimize dosing rate for the enhanced bioremediation of explosive compounds in surface soils and sediments of shooting ranges with indigenous microorganisms activated by external carbon source. Treatability study using slurry phase reactors showed that the presence of indigenous microbial community capable of explosive compounds degradation in the shooting range soils, and starch was a more effective carbon source than glucose and acetic acid in the removal of TNT. However, at higher starch/soil ratio, i.e., 2.0, the acute toxicity of the liquid phase increased possibly due to transformation products of TNT. RDX degradation by indigenous microorganisms was also stimulated by the addition of starch but the acute toxicity of the liquid phase decreased with the increase of starch/soil ratio. Taken together, the optimum range of starch/soil ratio for the degradation of explosive compounds without significant increase in acute toxicity was found to be 0.2 of starch/soil.

• 아시안잔디학회지
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• 제11권4호
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• pp.281-288
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• 1997

This study was performed to find out the mineral cycles of sulphur in dynamic grassland ecosystems in a steady state condition at the northwest side on Mt. Kwanak. The experimental results may be summarized on the communities of a Zoysia japonica and a Miscanthus sinensis as follows. As compared with some properties of the surface soils among two semi-natural grasslands, sulphur war greater quantity in a Miscanthus sinensis than in a Zoysia japonica on Mt. Kwanak . For the case of steady production and release, the raion of annual mineral production to the amount accumulated on the top of mineral soil in a steady state provides the estimates of release constant k. The release constants on sulphur of the litter were 0.54 in a Zoysia japonica and 0.36 in a Miscanthus sinensis grassland. The half times of S required for the release or accumulation of the litter on the grassland were 1.28 years in a Zoysia japonica and 1.93 years in a Miscauthus sinensis The amounts of annual cycles for sulphur in the grassland ecosystem under the steady-state conditions were 20.65g /$m^2$ in a Zoysia japonica and 26.28g /$m^2$ in a Miacanthus sinensis grassland. Key words: Zoysia japonica Miscanthus sinensis Mt. Kwanak, Sulphur, Mineral cycles.

• Natural Product Sciences
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• 제27권3호
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• pp.141-150
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• 2021

This short review on the chemistry, pharmacological properties and patents of obovatol and obovatal from Magnolia obovata is the first publication. Pharmacological properties are focused on anti-cancer, anti-inflammatory, anti-platelet and neuroprotective activities. Obovatol and obovatal were first isolated from the leaves of M. obovata. Also reported in the bark and fruits of M. obovata, obovatol and obovatal are neolignans i.e., biphenolic compounds bearing a C-O coupling. Other classes of compounds isolated and identified from M. obovata include sesquiterpene-neolignans, dineolignans, trineolignan, lignans, dilignans, phenylpropanoids, phenylethanoid glycosides, flavonoids, phenolic acids, alkaloids, sesquiterpenes, ketone and sterols. The anti-cancer properties of obovatol and obovatal involve apoptosis, inhibition of the growth, migration and invasion of cancer cell lines. However, obovatol displays cytotoxicity against cancer cells but not obovatal. Similarly, anti-inflammatory, anti-platelet, neuroprotective, anxiolytic and other pharmacological activities were only observed in obovatol. The disparity in pharmacological properties of obovatol and obovatal may be attributed to the -CHO group present in obovatal but absent in obovatol. From 2007 to 2013, eight patents were published on obovatol with one mentioning obovatal. They were all published at the U.S. Patent and Trademark Office by scientists of the Korea Research Institute of Bioscience and Biotechnology (KRIBB) as inventors and assignee, respectively. Some future research and prospects are suggested.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제2권3호
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• pp.198-209
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• 2021

Xuan Thuy and Con Dao are natural Ramsar sites in Vietnam with different ecosystems, geography and topography. Avian fauna in these two Ramsar sites were recorded over a 2-year period from 2018 to 2019. A total of 234 bird species belonging to 57 families and 16 orders were confirmed in Xuan Thuy, while only 71 species involving 32 families and 12 orders were found in Con Dao. In total, 25 endangered species have been found in these two national parks based on the IUCN Red List. The Spoon-billed Sandpiper and Baer's Pochard are the most endangered species ranked as Critically Endangered, whereas Nicobar pigeon, which is endemic to Con Dao, is the only endangered bird species here. This study provides the list of bird species of international importance identified in these two wetlands.

• Journal of Forest and Environmental Science
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• 제37권1호
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• pp.69-78
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• 2021

This study aims to verify a difference between the years 2014 and 2019 of Uiryeong-Gil, which is operated by the Visitor-Reservation System, in terms of the cognition of system, operational effectiveness, and behavioral intention. The analysis is as follows. First, among the overall cognition of the Visitor-Reservation System, the satisfaction from - prevention for safety for accident, expansion to other parks, number of visitor restriction, and satisfaction with reservation method - increased compared to 2014. Second, among the effects of the Visitor-Reservation System operation, satisfaction shows differences in year-to-year levels in terms of resource protection, resource damage mitigation efficiency, natural experience opportunity, comfort of visit-environment, and prevention of illegal activities. Third, the analysis of the differences in the behavior of the Visitor-Reservation System showed that the satisfaction of visitors, revisit intention, and overall satisfaction differed per year. The results of this study are meaningful in that the Visitor-Reservation System is no longer the restriction, but the change in cognition for the protection of ecosystems and sustainable visiting in order to expand the Visitor-Reservation System into a sustainable policy.

• ALGAE
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• 제35권4호
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• pp.325-335
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• 2020

A new diatom species, Mayamaea vietnamica sp. nov., is described from Cát Tiên National Park in Vietnam. This species was discovered and described from soil samples. Algae from soil ecosystems in Vietnam are almost unknown. The new species is described on the basis of an integrated approach with molecular and morphological data, and comparison with similar species. In terms of molecular data, 18S rDNA (including V4 domain), and partial rbcL plastid genes show M. vietnamica sp. nov. is most closely related to M. terrestris N. Abarca and R. Jahn, and together they form a monophyletic group relative to other members of the genus. M. vietnamica sp. nov. differs from other species in the genus by the number of striae and areolae in 10 ㎛, number of areolae per stria, as well as shape and presence or absence of axial and central areas.

• 한국발생생물학회지:발생과생식
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• 제26권3호
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• pp.127-133
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• 2022

The seven oligonucleotides primers were consumed to produce the quantity of unique loci shared to each pen shell team (ULSEPT) and quantity of loci shared by the binary pen shell teams. 154 quantities of LSBPP, with a mediocre of 22.0 per primer, were noticed in the binary pen shell (Atrina pectinata) teams. 328 fragments were recognized in the pen shell team A (PSTA), and 257 in the pen shell team B (PSTB): 77 quantities of ULSEPT (23.48%) in the PSTA and 121 (47.08%) in the PSTB. The band-sharing amount (BS amount) between entity's no. 01 and no. 05 was the highest (0.884) between the binary PSTs. The median band-sharing amount of entities in the PSTA (0.685±0.011) was higher than in those invented from the PSTB (0.640±0.009) (p<0.05). The highest genetic distance presenting substantial molecular difference was between entities PECTINATA no. 06 and PECTINATA no. 04 (0.498). Through this study, it is possible a certain degree to contribute to increasing the cultivation of pen shells, conservation of species, protection of the natural environment, and preservation of ecosystems.

• ALGAE
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• 제37권3호
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• pp.185-204
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• 2022

The genus Coolia A. Meunier 1919 has a global distribution and is a common member of epiphytic dinoflagellate assemblages in neritic ecosystems. Coolia monotis is the type species of the genus and was the only known species for 76 years. Over the past few decades, molecular characterization has unveiled two species complexes that group morphologically very similar species, so their limits are often unclear. To provide new knowledge on the biogeography and species composition of the genus Coolia, 16 strains were isolated from Bahía de La Paz, Gulf of California. The species were identified by applying morphological and molecular approaches. The morphometric characteristics of all isolated Coolia species were consistent with the original taxa descriptions. Phylogenetic analyses (large subunit [LSU] rDNA D1 / D2 and internal transcribed spacer [ITS] 1 / 5.8S / ITS2) revealed a species assemblage comprising Coolia malayensis, C. palmyrensis, C. tropicalis, and the C. cf. canariensis lineage. This is the first report of Coolia palmyrensis and C. cf. canariensis in Mexico and C. tropicalis in the Gulf of California. Our results strengthen the biogeographical understanding of these potentially harmful epiphytic dinoflagellate species.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제3권1호
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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.