• Journal of Mushroom
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• v.10 no.4
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• pp.224-235
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• 2012

Quality change of winter mushroom were investigated during storage and distribution phase as influenced by storage temperature. According to storage period and temperature, amino acids, were analysed and quantified with the mushroom fruiting bodies using HPLC and morphological characteristics were investigated. Characteristic changes of winter mushroom fruiting bodies were described as follows during storage according to the storage temperature. Looking at the results of the analyzed amino acid contents, temperature between $-1^{\circ}C$ and $4^{\circ}C$ was optimal condition for the storage. At $4^{\circ}C$, the chemical composition tended to be maintained. On the other hand, the results indicate the rapid loss of nutrition at $-1^{\circ}C$ within 7 days of storage. Exceptionally, proline was shown to be increased. Brown line mushroom had a larger loss than white line mushroom. Based on this result, brown line mushroom have shown significant differences among varieties. Therefore, winter mushroom should be stored at $4^{\circ}C$ to minimize nutrient loss and to maintain freshness and mushrooms should be consumed within 14 days after harvest.

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.3
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• pp.135-140
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• 1988

This field experiment was carried out to determine the effects of cutting times (3,4 and 5 times $yr^{-1}$) and cutting heights (3, 6 and 9 cm) on the growth and dry matter(DM) yield of grasses grown under pine trees, and botanical composition of woodland pasture. The conditions of the experimental field was south direction with 30% of shade (ca. 70% of full sunlight). Annual DM yield was higher in the plots cut 4 times (6,097 kg) and 3 times (5,953 kg) than in 5 times (5,305 kg $ha^{-1}$). However, it ip considered that total nutrient yields may be not different among 3 treatments. The yield was significantly (P < 0.05) increased with higher cutting height, regardless of cutting time. The 9 cm of stubble height was very effective on both increasing DM production and seasonal distribution of DM. In botanical composition, 3 cm and 6 cm of cutting height accelerated the percentages of bareland and weeds, regardless of cutting time, particularly in summer season. However, 9 cm of stubble height maintained 80-85% of pasture grasses in all cutting times. In this experiment, therefore, cutting height was more important factor than annual cutting times for forage production and pasture longevity, and it is desirable to harvest 4-5 times per year (under this experimental field condition) with 9 cm of stubble height on woodland pasture.

• Journal of Plant Biology
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• v.35 no.3
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• pp.197-203
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• 1992

During the study of the distribution of cellular slime molds in Halla mountain of Korea, a new yellow-pigmented Dictyostelium was isloated. This exibited several distinctive features which differed from the published species, and was designated as a new species, Dictyostelium jlavidum sp. n. Hong et Chang (Type strain HL-1). It was cultivated at $20-22^{\circ}C$ on weak nutrient agar media, 0.1 L-P in association with Escherichia coli. Sorocarps were 4-10 mm or more in length, conspicuously yellow throughout or with sori, typically solitary, unbranched or sparsely and irregularly branched. Sorophores were strongly tapered from bases to tips. Bases were typically well-formed disks in form or conically expanded. Sori were yellow to yellowish in color, and the pigmentation intensified with age. Spores were long and thin elliptical, mostly $4.8-9.6{\times}1.9-3.8\;(ave.\;7.3{\times}2.8)\;\mu\textrm{m}$, L/B index about 2.4-2.8, without polar granules.anules.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.909-918
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• 2009

As a part of dissolved organic matter, dissolved organic carbon (DOC) or biodegradable DOC (BDOC) fraction in particular is one of important issues in water treatment. Due to role as a nutrient source for bacteria, BDOC, therefore, may cause regrowth problems in water distribution system. The main objectives of this study were to investigate the possibility to minimize the concentration of BDOC in advance water treatment process. DOC in water is fractionized into four fractions such as AnBDOC (adsorbable and non-biodegradable DOC) which possesses adsorption properties but no biodegradation ability; nABDOC (biodegradable and non-adsorbable DOC) which has biodegradation properties but no adsorption ability; ABDOC (adsorbable and biodegradable DOC) which has adsorption properties and biodegradable characteristic; and non-removal DOC (nAnBDOC) which do not have either adsorbability or biodegradability. BAC process was effective for adsorbable DOC (AnBDOC+ABDOC) removal. However, in some cases, the removal ratio of adsorbable DOC was not sufficient. BDOC removal rate is very low or irremovable. Thus, for the control of residual DOC, it is necessary to change the operation condition by BAC process. From the analysis results of DOC fractions, water treatment processes appeared to be effective because it could grasp a remarkable amount of biodegradable, adsorbable and non-removal DOC. The concentration of AOX in non-prechlorination process was reduced from 7.1 ${\mu}g$/L to 0.51 ${\mu}g$/L in BAC process followed by ozonation.

• Korean Journal of Microbiology
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• v.54 no.2
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• pp.98-104
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• 2018

Naegleria fowleri and Acanthamoeba spp. are free-living amoebas that are widely distributed in natural environments. Although uncommon, infection with these protozoans can cause fatal disease in humans and animals. In this study, in order to select the appropriate method to survey Naegleria fowleri and Acanthamoeba spp. in water samples, four molecular biology techniques and one commercially available kit for real-time PCR were compared. The results indicated that the duplex real-time PCR was the most sensitive, and could be used to simultaneously detect two different free-living amoebas. Using the duplex real-time PCR approach, the two free-living amoebas were surveyed in three local streams in Daejeon, Republic of Korea. The concentrated free-living amoebas were inoculated onto non-nutrient agar plates which had been spread with heat-inactivated Escherichia coli and incubated for 5~7 days. After incubation, gDNA was extracted and used as the template for amplification by duplex real-time PCR. Acanthamoeba spp. and N. fowleri was detected from ten (83.3%) and two (16.6%) of the twelve samples, respectively. As these two free-living amoebas can be fatal, continuous surveillance is needed to track their distribution in the aquatic environment for the drinking water safety.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.4
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• pp.262-268
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• 2014

The management of soil chemical properties is very important to sustainable agriculture of many horticultural crops, including cucumber. This study was conducted to find the optimal soil properties of environmentally friendly agriculture in controlled horticulture. Soil chemical properties of 267 samples were collected from soil in Chungnam Province. The average of pH, EC, OM, available $P_2O_5$, exchangeable K, Ca, and Mg was 6.1, $5.38dS\;m^{-1}$, $34g\;kg^{-1}$, $1,321mg\;kg^{-1}$, $1.50cmol_c\;kg{-1}$, $10.3cmol_c\;kg{-1}$, and $3.4cmol_c\;kg{-1}$, respectively. The organic matter content in silty clay loam was significantly higher than in the other soil textures, whereas the pH, EC, exchangeable K, and Mg in loamy fine sand showed significantly lower among soil textures. The EC value and exchangeable Mg concentration were highest in mountain foot-slope soils. The frequency distribution within optimum range of soil chemical properties was 26.2%, 30.3%, 2.3%, 3.8%, 3.4%, and 6.7% for pH, OM, available $P_2O_5$, exchangeable K, Ca, and Mg, respectively. Especially, excessive portion of available $P_2O_5$ and exchangeable Ca were 94.0% and 94.4%, respectively. The EC value and organic matter content of soil samples were positive correlation with all chemical properties except soil pH. In principle component analysis of chemical properties in soil samples, the percentage of variance explained by PC 1 was 52.2%, while PC 2 explained 21.3% of the variance, for a cumulative total of 73.5%. In conclusion, these results are considered to improve soil nutrient management for sustainable controlled horticulture.

• Korean Journal of Ecology and Environment
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• v.42 no.2
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• pp.212-220
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• 2009

In this study, we analyzed fish compositions and ecological characteristics such as trophic guilds and tolerance guilds in association with water quality characteristics in Masan Reservoir during November 2008. Total number of species were 12 species (6 families) and the dominant species were Zacco platypus, Hemiculter eigenmanni, and Pseudorasbora parva. We found three Korean endemic species and one exotic species, Carassius cuvieri. According to the analysis of ecological indicator characteristics, relative proportion of tolerant and omnivore species was 98% of the total indicating that probably, the fauna was influenced by physical habitat disturbance and physicochemical degradations. Fish distribution analysis along with littoral zone showed that the most fishes (${\sim}$95%) were observed in the littoral zone where emerged macrophytes were well developed. Also, substrate analysis indicated that the most species were found near silt area (11 species, 91.7%), so that the significant differences were found between the substrate types. Analysis of water quality indicated that concentrations of total phosphorus (TP) and chlorophyll-a (ChI-a) as a lake trophic indicator were judged as eutrophic states, respectively and COD as an indicator of organic matter pollution averaged 10.9 mg $L^{-1}$. Based on the water quality, this system were influenced by the nutrient enrichments and organic matter. The degradations of water quality in Masan Reservoir resulted in trophic compositions of fish (increase of omnivore species) and the dominance of tolerant fish. This Monitoring data may contribute changes of fish fauna and compositions in relation to habitat modifications and chemical water quality degradations in the future.

• Journal of Nutrition and Health
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• v.26 no.4
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• pp.390-404
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• 1993

The purpose of this paper is to determine the percentage of body fat by measurement of skin-fold thickness of the triceps and the subscapular area to investigate the relationship between the daily energy intake and expenditure among obese women and nonobese women based on the percentage of body fat and age. This survey included 422 females in Cheju. 1) The age distribution of the 422 females surveyed was : 26.8% were in their 20's, 20.6% in their 30's, 21.3% in their 40's, 19.0% in their 50's and 12.3% were above 60 years of age. The 422 females consisted consisted of 78% housewives, 12.8% college student and 9.2% single working women. 2) The average height and weight of the surveyed women were respecitively 159.0$\pm$4.2cm and 56.0$\pm$7.2kg, the percentage of body fat of the surveyed women was 24.8$\pm$9.8%, and the BMI of those surveyed was 22.7$\pm$2.7. If higher than 30% body fat was defined as being obese, 15.6% of the surveyed women were assessed to be obese. 3) Total daily food consumption and energy intake of the group of women aged 60 and older was significantly small. Food consumption and nutrient intake of obese women was greater than that of the nonobese group, but not significant. Carbohydrate intake of the obese group in their 40's was significantly higher than the nonobese group. Total food consumption, energy and carbohydrate intake of the obese group in their 50's was significantly higher than the nonobese group. Vegetable intake of the obese group in their 60's and older was significantly higher than the nonobese group. 4) The total time of physiological activity of women aged 60 and older was significantly higher than for the other age groups and the total work time was significantly lower. The total work time of women in their 20's was not lower than the other groups. Considering the low energy expenditure of physical activity for women in their 20's, they appeared to have light activity. However, there was not a significant difference in the physical activity time among middle aged women groups(from 30 to 50). The entire energy expenditure of the obese group was greater than the nonobese group. However, the energy expenditure per body weight in the obese group was significantly less than that of the nonobese group in terms of the basal metabolic rate in consideration of the fat free mass. 5) There was a positive correlation between the percentage of body fat and the factors of age, sleeping time, total time of physiological activity, housework time, time spent watching TV, energy expenditure, energy intake, carbohydrate and cereal consumption. On the other hand, the percentage of body fat was negatively correlated with energy expenditure per body weight based on the basal metabolic rate in consideration of the free mass.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.238-238
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• 2015

There are demands for water environmental analysis of discharge processes in paddy fields, however, it is not fully understood in nutrients discharge process for watershed modeling. As hydrological processes both surface and ground water and agricultural water managements are so complex in paddy fields, the development of lowland paddy fields watershed model is more difficult than upland watershed model. In this research, the improvement of SWAT (Soil and Water Assessment Tool) model for a paddy watershed was conducted. First, modification of surface inundated process was developed in improved pot hole option. Those modification was evaluated by monitoring data. Second, the monitoring data in river and drainage channel in lowland paddy fields from 2012 to 2014 were analyzed to understand discharge characteristics. As a case study, Imbanuma basin, Japan, was chosen as typical land and water use in Asian countries. In this basin, lowland paddy fields are irrigated from river water using small pumps that were located in distribution within the watershed. Daily hydrological fluctuation was too complex to estimate. Then, to understand surface and ground water discharge characteristics in irrigation (Apr-Aug) and non-irrigation (Sep-Mar) period, the water and material balance analysis was conducted. The analysis was composed two parts, watershed and river channel blocks. As results of model simulation, output was satisfactory in NSE, but uncertainty was large. It would be coming from discharge process in return water. The river water and ground water in paddy fields were exchanged each other in 5.7% and 10.8% to river discharge in irrigation and non-irrigation periods, respectively. Through this exchange, nutrient loads were exchanged between river and paddy fields components. It suggested that discharge from paddy fields was not only responded to rainfall but dynamically related with river water table. In general, hydrological models is assumed that a discharge process is one way from watershed to river. However, in lowland paddy fields, discharge process is dynamically changed. This function of paddy fields showed that flood was mitigated and temporally held as storage in ground water. Then, it showed that water quality was changed in mitigated function in the water exchange process in lowland paddy fields. In future, it was expected that hydrological models for lowland paddy fields would be developed with this mitigation function.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.6
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• pp.588-592
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• 2015

Soil testing is one of the major strategies for establishing sustainable agricultural practice as it analyzes nutrient contents of soil and determines the amount of nutrients required for crop growth. Soil testing for the field cultivating regional major crops in Korea has been conducting by National Academy of Agricultural Science (NAAS), provincial agricultural research & extension services and agriculture technology centers since 2000. 1,006,227 soil samples were analyzed and uploaded on Korean soil information system (http://soil.rda.go.kr) from 2003 to 2013. Soil pH has changed from 6.1 to 6.2. Organic matter (OM), available (Avail.) phosphate and exchangeable (Exch.) K have decreased from 24 to $23gkg^{-1}$, 541 to $399mgkg^{-1}$ and 0.90 to $0.72cmol_ckg^{-1}$ between 2003 and 2013, respectively. Especially, Exch. Ca contents decreased to $5.7cmol_ckg^{-1}$ in 2009 and increased to $6.2cmol_ckg^{-1}$ in 2013. Ratios of optimal ranges for cropping were 48% for pH, 22% for OM, 26% for Avail. phosphate, and 23, 16, 22% for Exch. K, Ca and Mg in 2013. Ratios of optimal ranges for pH increased and low ranges for OM, Avail. phosphate and Exch. K increased. Frequency distribution was 64% for pH 5.5~7.0, 65% for OM $10{\sim}30gkg^{-1}$, 48% for Avail. phosphate under $300mgkg^{-1}$ and 23, 29, 22% for Exch. K 0.2~0.6, Ca 4.0~6.0 and Mg $1.0{\sim}1.5cmol_ckg^{-1}$.