• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.502-507
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• 2016

This study was designed to investigate the beneficial effects of fermented Rhus verniciflua stem bark extract (RVSBE) on the stomach. We evaluated RVSBE for its antimicrobial activity against Helicobacter pylori (H. pylori), along with its ability to reduce the viability of human gastric cancer AGS cells. In addition, its anti-inflammatory effect was examined by evaluating nitric oxide (NO) production, and inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 mRNA expression in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. RVSBE showed antimicrobial activity, as 2.0 mg of the extract produced a clear inhibition zone of 4.0 mm. RVSBE inhibited the growth of AGS cells by 20% at concentrations ranging from 0.25-1.0 mg/mL. Regarding the anti-inflammatory effects of RVSBE, at 0.1-1.0 mg/mL, the extract showed more than 75% inhibition of NO production. In addition, cells treated with 0.25 mg/mL RVSBE showed a 25% decrease in iNOS mRNA levels compared to those in the LPS-treated cells. These results suggest that RVSBE may have significant inhibitory effects on inflammatory mediators, and therefore, may be a potential anti-inflammatory candidate.

• Journal of Korean Society of Forest Science
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• v.79 no.2
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• pp.109-114
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• 1990

The axillary buds of 15-year-old Tilia amurensis were cultured on Saito and Ide (IS), Murashige and Skoog (MS) media and woody plant medium (WPM) to establish an effective micropropagation method. Five levels of 6-benzylaminopurine (BAP) were tested. On IS medium and WPM addition of 1.0/l BAP enhanced shoot development and shoot elongation, whereas addition of 0.5/l BAP was effective on MS medium. A better results were obtained from WPM with 1.0/l BAP and MS with 0.1/l BAP. Developed shoots were subcultured on each basal media but with 0.2/l BAP, Multiple shoots were almost doubled in a month. Root formation could be enhanced at higher concentration of indole-3-butyric acid (IBA). Better rooting rate (83.3%) was achieved on a half-strength MS medium with 3.0 /l IBA. Regenerated plantlets were successfully transferred to soil. To investigate the clonal variation in shoot development and shoot elongation by axillary bud culturing, seven plus tree clones were tested, Clonal variation in tissue culturability among plus trees was recognized by the Duncan's multiple range test at the 5% level. Kang Won No. 12 showed the best response on WPM with 1.0/l BAP.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.591-594
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• 2011

A new poinsettia(Euphorbia pulcherrima. Willd. ex Klotzch) cultivar 'Red Stone' was bred by the National Institute of Horticultural and Herbal Science (NIHHS) in 2009. In 2006, a cross was made between 'Freedom Rose', a cultivar with vigorous growth and deep pink bracts, and 'Enduring Pink', a cultivar with pink bracts early colored. 'Red Stone' was finally selected in 2009 after the investigation of the growth and flowering characteristics from 2007 to 2009. 'Red Stone' has red elliptic bracts and strong rugosities between bract veins. Leaf blade is ovate and very dark green. Stem color is reddish and petiole length is medium but relatively longer than that of 'Pepride Red', control cultivar. 'Red Stone' develops as many as 3.8 branches and which is more than double of 'Pepride Red'. Its bracts and transitional leaves are fully colored at 7.5 weeks after short-day commencement. Plant variety protection right of 'Red Stone' was registered in April 2011, and its grant number is 3487.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.696-701
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• 2011

This study was conducted to investigate impacts of soil properties on microbial distribution in Jeonbuk orchard fields. Soil samples were collected from 110 sites cultivated with different fruit plants. The population of aerobic bacteria and fungi and the content of soil microbial biomass carbon (C) were found to increase with increasing silt content in the soils. Different activity of dehydrogenase was not observed among the different textures of soil. Microbial distribution, amount of microbial biomass C, and dehydrogenase activity in the soils were not significantly different among the topographic sites. However, in pear and grape fruit plant fields, coliform group of bacteria was found in relatively higher population, $133.0{\times}10^3\;CFU\;g^{-1}$ and $107.4{\times}10^3\;CFU\;g^{-1}$, respectively. Microbial groups were simplified and their density was reduced with increasing the cultivation periods of fruit plants. The soil microbial distribution was proportionally correlated with some of soil properties such as soil pH, soil organic matter (SOM) content, and exchangeable Mg content; in particular, the population of Bacillus sp. was proportionally correlated with soil pH and exchangeable Mg content. The amounts of microbial biomass C and the dehydrogenase activity in the soils were significantly correlated with the contents of SOM and exchangeable Ca ion (p<0.01).

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.3
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• pp.183-188
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• 2021

The increase in temperature due to climate warming is predicted to affect crop yields in the future. Until now, various types of OTC (open top chamber) that simulate the future climate condition have been developed and used to study the effect of temperature increase due to global warming on maize growth. However, in most OTCs, high equipment and maintenance costs were required to artificially increase the temperature. This study was carried to develop a cost-effective and simple OTC suitable for climate warming experiments for forage maize. Three octagonal OTCs with a height of 3.5 m × a diameter of 4.08 m and a partially covered top were constructed. The lower part of OTC covered film was opened at a height of 26 cm (OTC-26), 12 cm (OTC-12) from the ground surface, or not opened (0 cm, OTC-0). Mean air temperatures during the daytime on a sunny day in OTC-0, OTC-12 and OTC-26 increased to 3.23℃, 1.33℃, and 0.89℃, respectively, compared to the ambient control plot. For a pilot test, forage maize, 'Gwangpyeongok' was grown at OTCs and ambient control plots. As a result, in the late maize vegetative growth phase (July 30), the plant height was increased more than 45% higher than the ambient control plot in all OTC plots, and the stem diameter also increased in all OTC plots. These results indicate that it is possible to set the temperature inside the OTC by adjusting the opening height of the lower end of the OTC, and it can be applied to study the response of forage maize to elevated temperature. An OTC, with its advantages of energy free, low maintenance cost, and simple temperature setting, will be helpful in studying maize growth responsiveness to climate warming in the future.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.2
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• pp.74-88
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• 2021

In the present study, the characteristics and changes in the vegetation of Mt. Cheongryang, Inchon, were examined to identify and determine appropriate ways to restore the health of the urban forest and to preserve its vegetation. The vegetation of the community of Quercus mongolica (Mongolian oak) on Mt. Cheongryang appeared to decrease in response to the control of the wilt disease of oak trees. The communities of Sorbus alnifolia (Korean mountain ash) and Styrax japonicus (Snowbell tree) have increased. Pinus rigida (Pitch Pine) had its overall territory decrease, but the current state of the Pinus rigida (Pitch Pine) was estimated to be stable due to its dominance as a tree layer species. In regards to Robinia pseudoacacia (Black Locust), the urbanized species of Sorbus alnifolia (Korean mountain ash), and Styrax japonicus (Snowbell tree), their areas have increased with the appearance of Magnolia obovate (Whiteleaf Japanese Magnolia). The biodiversity of Mt. Cheongryang has decreased by simplifying species in the tree layer and understory species thereof, and the initial success of species in marginal areas has increased. The absence of potential succession was attributed to the termination of ecological succession; thereby, the current vegetation structure was concluded to be remaining as it is for the time being. Soil texture in the mountain primarily consisted of sandy loam or loamy sand; the pH of the soil was in the range 4.26-4.86, rendering a mean pH of 4.59. The content of organic matter (O.M.) appeared having a distributing range of 2.18-9.60%, rendering a mean value of 4.33%. To promote species diversity, several methods are suggested, such as prevention of soil acidification, selecting nationally-grown trees from moist soil or valleys for afforestation, preventing species appearing due to urbanization or excessive growth, protecting the understory vegetation and species with hygropreference, and managing the forest to maintain a multi-layered vegetation structure.

• Korean Journal of Organic Agriculture
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• v.28 no.4
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• pp.615-626
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• 2020

The objective of present experiment was to examine the impact of different organic nitrogen (N) fertilizer application rates and different harvesting periods on the forage yield and feed value of kenaf (Hibiscus cannabinus L.). This study was carried out from May to September 2019, the amount of 80 kg of kenaf seed/ha were applied with different rates of nitrogen fertilizer. The plants were sampled at 10 days intervals (100, 110, 120, and 130 days after seeding) from different harvesting dates. In the organic fertilizer treatments, the highest dry matter (DM) yield was observed in the application rate at 250 kg of N/ha. Crude protein (CP) content in leaves was similar between the organic fertilizer rates at 200 and 250 kg of N/ha and were higher compared with other fertilizer treatments. The highest CP content in the stem was 4.3% in the organic fertilizer application rates st 250 kg of N/ha. Neutral detergent fiber (NDF) in leaves showed no significant difference between the chemical fertilizer rates at 200 and 250 kg of N/ha, and the organic fertilizer rates at 150 and 250 kg of N/ha. In addition, DM yield of kenaf was highest in the harvest of 100 days after seeding, and tended to decreased significantly with increase of harvesting periods (p<0.05). As the growth progressed, the plant height and stem ratio increased but the leaves ratio decreased significantly (p<0.05) and the highest was found at 110 days after seeding. The highest CP, Acid detergent fiber (ADF), NDF and total digestible nutrient (TDN) contents in leaves were 13.9, 25.4, 40.5 and 71.1%, respectively that were affected by different harvesting periods. Also, the ADF and NDF in stem increased significantly with increase of kenaf maturity (p<0.05). In conclusion, the optimal organic fertilizer application rates and the proper harvesting periods for the forage yield and quality of kenaf were at 200 to 250 kg of N/ha, and 100 to 110 days after seeding, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.4
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• pp.390-398
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• 2018

Miscanthus is a perennial energy plant that reproduces via rhizomes and has C4 metabolism. The flowering pattern of a wild type M. sacchariflorus (WTM) is affected by environmental conditions such as photoperiod and soil water status. Geodae-Uksae 1 (Geodea), which is a new M. sacchariflorus cultivar, has a lower heading rate than WMS; however the mechanism with why this happens is unknown. To confirm the effects of drought or waterlogging stresses on the growth of WTM and Geodea at the reproductive stage, we investigated variations in morphological characteristics and nutrient contents of the two Miscanthus species after four months of three water treatments. Morphological traits of the two Miscanthus species under the drought condition were similar to those under the control condition. But, the height of Geodea increased by 30% in response to the waterlogging stress. In WTM, the heading rate under the drought condition was lowest, while there was no significant difference between the waterlogging and control conditions. In the two Miscanthus species, nutrient contents, such as sucrose, total N, $P_2O_5$, K and Mg, were the highest under the drought condition, wherea Ca and Mg contents under the waterlogging condition were more than three times lower than those under the drought condition. The current study results showed that drought stress accelerated senescence and then inhibited nutrient mobilization in WTM, while waterlogging stress promoted the growth. This study is the first report to confirm that waterlogging stress promotes flowering of M. sacchariflorus.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.471-478
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• 2018

The purpose of this study was to investigate effects of reusable organic wastes, on soil organisms and chemical properties. Bone meal, de-oiled cake, and oyster shell were applied and abundances of soil organisms were measured at 3 and 15 months, after treatment in soil under sawleaf zelkova cultivation. Soil organisms are affected, by the quality of applied organic wastes. Abundance of microorganisms was higher in oyster shell treated soils than in untreated soils, suggesting that soil pH is a driving force, altering abundance and structure of the microbial community. Increase in abundance of bacterivorous nematodes was observed under treatment with bone meal and de-oiled cake, but there was slight change in abundance of fungivorous and herbivorous nematodes. Abundance of herbivorous nematode was positively correlated with plant growth, at 15 months after treatment. Response of microarthropods in the Collembola and Oribatida was not apparent. Abundances of primary consumers were not significantly correlated with microorganisms. This study suggested that organic waste influences soil organisms primarily by altering soil chemical properties and bottom-up effects may not occur in trophic reactions.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.6
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• pp.253-262
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• 2018

Oscillating Water Column (OWC) Wave Energy Converters (WEC) harness electricity through a Power-Take-Off (PTO) system from the induced-airflow by seawater oscillating inside a chamber. In general, an air chamber with a relatively small cross-sectional area is required compared to seawater chamber to obtain high-velocity air in the PTO system, and in order to simulate an accurate air flow rate in the air chamber, a three-dimensional study is required. In this study, the dynamic response of OWC-WEC that is equipped with the channel of seawater exchange for the case of irregular waves has been numerically studied. The open source CFD software, OLAFLOW for the simulation of wave dynamics to the openFOAM and FOAM-extend communities, was used to simulate the interaction between the device and irregular waves. Based on the numerical simulation results, we discussed the fluctuation characteristics of three dimensional air flow in the air-chamber, wave deformation around the structure and the seawater flow inside the channel of seawater exchange. The numerical results the maximum air flow velocity in the air-chamber increases as the Ursell value of the significant wave increases, and the velocity of airflow flowing out from the inside of air chamber to the outside is greater than the speed of flowing into the air chamber from the outside.