• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.3
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• pp.12-24
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• 2002

The purpose of this paper is to decompose the effect of resources of natural parks(NP) on user's satisfaction to answer the research question: What are the causal effects of resources of natural parks on user\ulcorner After reviewing the literature, classification of resources of NP, various approaches and analysis methods employed, we constructed the conceptual framework and have formulated the hypothesis of this research. We had obtained data through a questionnaire, which surveyed 414 visitors at 6 of the 73 NP in Korea in 2001, based on a stratified sampling method. We have analyzed the data using descriptive statistical methods, Pearson's correlation analysis, and a path analysis method. We found that 1) While the indirect effect of topographical feature and valley(TFV), socio-cultural resources(SCR), and climate, sound, and scent(CSS) turned out to be 2.75, 1.20, and 2.00 times higher than that of wild animal and plant(WAP), the direct effect of TFV, SCR, and landscape turned out to be 2.95, 2.88, and 2.64 times higher than that of CSS, 2) The magnitude of causal effects of the three exogeneous variables of TFV, WAP, and SCR and two intervening variables of CSS and landscape on User's satisfaction turned out to be 0.403, 0.048, 0.323, 0.188, and 0.243, respectively, 3) Total direct effect of the exogeneous and intervening variables on user's satisfaction is 0.871, while that of indirect effect is 0.334, and 4) Causal effect of tangible resources is 1.80 times higher than that of intangible while total effect of tangible resources are 1.36 times higher than that of intangible. The research results suggest that 1) Criteria for designation and maintenances of NP and results of previous studies on resources turned out to be unreliable and distorted, 2) In the criteria of planning and maintenance of NP, intangible resources must be included, 3) Remedial directions to increase user's satisfaction should be focused on maintenance of TFV and landscape in NP, and 4) The approach and path analysis adopted by this research is valid and highly useful for other resource based recreation area. It is recommended that more empirical study on seasonal variation of resources in NP based user's preference be performed in the future.

• Animal cells and systems
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• v.14 no.4
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• pp.305-313
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• 2010

Pacific abalone Haliotis discus discus is an important fisheries resource in Jeju, Korea. For basic information about its current genetic status in relation to stock enhancement, the level and distribution of genetic variation between wild and released stocks of Pacific abalone in Jeju were examined at nine cross-species microsatellite markers including the use of two novel primers. High levels of polymorphism were observed between the two populations. A total of 146 different alleles were found at all loci, with some alleles being unique. The allelic variability ranged from five to 27 in the wild population and from four to 16 in the released sample. The average observed and expected heterozygosities were estimated to be 0.74 and 0.84 in the wild sample and 0.70 and 0.78 in the released sample, respectively. Although a considerable loss of rare alleles was observed in the released sample, no statistically significant reductions were found in heterozygosity or allelic diversity in the released sample compared to the wild population. Low but significant genetic differentiation was found between the wild and released populations. These results suggest that the intensive breeding practices for stock enhancement may have resulted in a further decrease in genetic diversity, and that the cross-species microsatellite markers used in this study represent a potentially efficient means for further genetic studies, providing beneficial information for the protection and management of H. discus discus.

• Korean Journal of Plant Resources
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• v.30 no.4
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• pp.372-377
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• 2017

This research was performed to develop mass propagation method of Alpine modest primrose (Primula modesta var. hannasanensis T.Yamaz.) for improving the conservation and utilization of the species. Seeds were collected on August 2011 in Jeju-city and well-selected seeds were dry-stored at $4{\pm}1.0^{\circ}C$. Seed size ranged $0.44{\pm}0.07{\times}0.61{\pm}0.04mm$, and weight of 1,000 seeds was $51.78{\pm}0.021mg$. Thus the seed was classified as 'dwarf seeds'. As the result of dormancy characteristics, moisture content of freshly matured seeds increased rapidly by water-soaking treatment and seeds did not germinate at $20^{\circ}C$ for 4 weeks under the light condition. Therefore, seeds were estimated to have physiological dormancy. Germination conditions of dry-stored seeds were found to be $20^{\circ}C$ and light condition, and seeds did not germinated under dark condition regardless of all temperature regimes. Therefore, Alpine modest primrose seed was considered as photoblastic type. Percent germination (PG) and germination energy (GE) were greatly improved by soaking the seeds in $GA_3$ and kinetin for 24 hours. Especially, 200~500 mg/L $GA_3$ treatment resulted in the highest PG (95.5%) and GE (98.3%). So, chemical treatment such as $GA_3$ was thought to be a useful method for raising seedling uniformly.

• Journal of the Korean Chemical Society
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• v.54 no.2
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• pp.192-197
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• 2010

The spinel compound was obtained by the thermal decomposition of Zn-Co and Zn-Ni gel prepared by sol-gel method using oxalic acid as a chelating agent. The formation of spinel compound has been comfirmed by thermogravimetric analysis (TGA), x-ray powder diffraction (XRD) and infrared spectroscopy (IR). The particle size of 13 nm~16 nm was calculated by Scherrer's equation. The sol-gel method provides a practicable and effective route for the synthesis of the spinel compound at low temperature ($350^{\circ}C$). The kinetic parameters such as activation energy (Ea) and pre-exponential factor (A) for each compound were found by means of the Kissinger method and Arrhenius equation. The decomposition of spinel compound has an activation energy about 155 kJ/mol. Finally, the thermodynamic parameters (${\Delta}G^{\varphi}$, ${\Delta}H^{\varphi}$, ${\Delta}S^{\varphi}$) for decomposition of spinel compound was determined.

• Korean Journal of Microbiology
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• v.52 no.2
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• pp.166-174
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• 2016

In order to find an efficient bacterial strain that can carry out nitrification and denitrification simultaneously, we isolated many heterotrophic nitrifying bacteria from wastewater treatment plant. One of isolates NS13 showed high removal rate of ammonium and was identified as Alcaligenes faecalis by analysis of its 16S rDNA sequence, carbon source utilization and fatty acids composition. This bacterium could remove over 99% of ammonium in a heterotrophic medium containing 140 mg/L of ammonium at pH 6-9, $25-37^{\circ}C$ and 0-4% of salt concentrations within 2 days. It showed even higher ammonium removal at higher initial ammonium concentration in the medium. A. faecalis NS13 could also reduce nitrate and nitrous oxide by nitrate reductase and nitrous oxide reductase, respectively, which was confirmed by detection of nitrate reductase gene, napA, and nitrous oxide reducase gene, nosZ, by PCR. One of metabolic intermediate of denitrification, $N_2O$ was detected from headspace of bacterial culture. Based on analysis of all nitrogen compounds in the bacterial culture, 42.8% of initial nitrogen seemed to be lost as nitrogen gas, and 46.4% of nitrogen was assimilated into bacterial biomass which can be removed as sludge in treatment processes. This bacterium was speculated to perform heterotrophic nitrification and aerobic denitrification simultaneously, and may be utilized for N removal in wastewater treatment processes.

• Journal of Microbiology and Biotechnology
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• v.14 no.3
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• pp.584-592
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• 2004

A thermostable $\beta$-glycosidase gene, tfi $\beta$-gly, was cloned from the genomic library of Thermus filiformis Wai33 A1. ifi $\beta$-gly consists of 1,296 bp nucleotide sequence and encodes a polypeptide of 431 amino acids. It shares a strong amino acid sequence similarity with the $\beta$-glycosidases from other Thermus spp. belonging to the glycosyl hydrolase family 1. In the present study, the enzyme was overexpressed in Escherichia coli BL21 (DE3) using the pET21b(+) vector system. The recombinant enzyme was purified to homogeneity by heat treatment and a $Ni^{2+}$-affinity chromatography. Polyacrylamide gel electrophoresis (PAGE) showed that the recombinant Tfi $\beta$-glycosidase was a monomeric form with molecular mass of 49 kDa. The temperature and pH range for optimal activity of the purified enzyme were 80- $90^{\circ}C$ and 5.0-6.0, respectively. Ninety-three percent of the enzyme activity was remained at $70^{\circ}C$ after 12 h, and its half-life at $80^{\circ}C$ was 6 h, indicating that Tfi $\beta$-glycosidase is highly thermostable. Based on its K_m$, or $K_{cat}K_m$, ratio, Tfi $\beta$-glycosidase appeared to have higher affinity for $\beta$-D-glucoside than for $\beta$-D-galactoside, however, $K_{cat} for \beta$-D-galactoside was much higher than that for $\beta$-D-glucoside. The activity for lactose hydrolysis was proportionally increased at $70^{\circ}C$ and pH 7.0 without substrate inhibition until reaching 250 mM lactose concentration. The specific activity of Tfi TEX>$\beta$-glycosidase on 138 mM lactose at $70{^\circ}C$ and pH 7.0 was 134.9 U/mg. Consequently, this newly cloned enzyme appears to have a valuable advantage of conducting biotechnological processes at elevated temperature during milk pasteurization in the production of low-lactose milk.

• Korean Journal of Microbiology
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• v.42 no.2
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• pp.142-148
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• 2006

In order to develop chitosanase for the production of chitosan oligosaccharides, a chitosanase-producing bacterium was isolated from the traditional fermented soybean, Meju, and identified as Bacillus amyloliquefaciene MJ-1. The cloned chitosanase gene, 825 bp in size, encoded a single peptide of 274 amino acids with a estimated molecular mass of 30.9 kDa. The deduced amino acid sequence showed significant homology with microbial chitosanases. The recombinant chitosanase was expressed in Escherichia coli upon induction with isopropyl-D-thiogalactopyranoside, and purified using $Ni^{2+}-NTA$ agarose column chromatography. The maximal activity of the recombinant chitosanase is at pH 5.0 and $60^{\circ}C$. The recombinant chitosanase is stable between pH 5.0 and pH 7.0 at $37^{\circ}C$ for 30 min, and more than 75% of the activity still remain at $80^{\circ}C$ for 30 min incubation.

• Journal of Physiology & Pathology in Korean Medicine
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• v.29 no.1
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• pp.46-50
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• 2015

Both Portulaca oleracea (PO) and Glechoma hederacea (GH) have been used as traditional medicine due to the multiple pharmacological activities. However, the effects of PO and GH in the pathology of periodontitis is still elusive. In this study, we examined anti-microbial activity of PO ethanol extract (POEE) and GH ethanol extract (GHEE) in vitro, and physiological effects of POEE and GHEE on the cell inflammatory responses and the severity of periodontitis were determined using the rat periodontitis model. Our results indicate that POEE and GHEE had no effects on the proliferation of streptococcus mutans and on LPS-mediated inflammatory responses in gingival fibroblast cells. Notably, ingestion of POEE and GHEE resulted in attenuating the severity of periodontitis and population change of immune cells. These data suggests that PO and GH should be considered as candidates for relieving the severity of periondontitis.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.5
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• pp.379-384
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• 2009

This study was carried out to understand the national and regional distribution of the biomass resources produced in Korea annually via establishing database (DB) and distribution maps of biomass resources data including as livestock manures, food wastes and agricultural by-product. The information of the annual production of each biomass resources was obtained from Ministry for Food, Agriculture, Forestry and Fisheries (MIFAFF), Ministry of Environment (MOE) and National Statistical Office (NSO). Based on biomass resources data, we established database architecture table about livestock manures and food wastes. The distribution maps for the total amount of manures produced from each livestock animal were built up in both national and regional scales and used for analysis of the space-based and time-based distribution of the manure resources. Distribution maps for food wastes and agricultural by-product were also produced, respectively. It was shown that the analysis through resource mapping can be used to identify the sources of collectable biomass feasibly determining suitable region for establishment of a biomass-energy production. The biomass distribution maps graphically provide the information regarding biomass resources to policy-makers, farmers, general users and it was expected to be utilized for policy-making of environmental-friendly agriculture and bio-energy.

• Journal of Life Science
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• v.28 no.11
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• pp.1332-1338
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• 2018

Activated microglia, induced by various pathogens, protect neurons and maintain homeostasis of the central nervous system (CNS). However, severe activation causes neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease because of the secretion of various neurotoxic molecules, such as nitric oxide (NO), prostaglandin (PG), and pro-inflammatory cytokines. Because chronic microglial activation endangers neuronal survival, negative regulators of microglial activation have been identified as potential therapeutic candidates for treatment of many neurological diseases. One potential source of these regulators is Locusta migratoria, a grasshopper of the Acrididae, usually 4-6 cm in size, belonging to the family of large insects in Acrididae. This grasshopper is an edible insect resource that can be consumed by humans as protein source or used for animal feed. The aim of the present study was to examine the inhibitory effects of a L. migratoria ethanol extract (LME) on the production of inflammatory mediators in LPS-stimulated BV-2 microglia cells. The extract significantly inhibited the NO, iNOS, COX-2, and pro-inflammatory cytokine ($TNF-{\alpha}$, IL-6 and $IL-1{\beta}$) levels in BV-2 microglia cell. Because the inhibition of microglial activation may be an effective solution for treating brain disorders like Alzheimer's and Parkinson's diseases, these results suggest that LME may be a potential therapeutic agent for the treatment of brain disorders induced by neuroinflammation.