• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.1
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• pp.1-7
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• 1980

In 1976, a newly released rice variety, Yushin, was planted in 300,000 ha of the 533,000 ha of cultivated total hecterage with new rice varieties. High productivity and quality were achieved by farmers around country. However, the wilting phenomena of Yushin occured in some regions where were employed poor cultural management, and flowed sewage into the paddy field from industrial factories. This study was identified some factors for the wilting phenomena of Yushin rice variety in morphological and physiological aspects. The Yushin variety showed greater internode elongation on low part of the stems that close related to lodge at heavier nitrogen levels, excessive number of spikelets per unit leaf blade weight i.e. higher sink/source ratio, and greater consumption of respiratory substrate by increased respiration rate of rice plant as compared with those of Tongil rice variety. In physilogical aspects, the Yushin variety was significantly declined root development and root activities under heavy nitrogen conditions. Yushin rice variety was decreased $K_2$O/N ratio, carbohydrate content in stem of rice plant, and physiological root activities specially in low light intensity, 50% light interception plots. Therefore, above factors were mainly promoted the wilting phenomena of Yushin rice variety.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.2
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• pp.137-145
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• 1981

Using the milled, blast infected leaves (BIL) as an inoculum source on the screening for the resistance to blast of rice plant was a simple and useful technique. The temperature with high (25^\circ C\sim 35^\circ C) and low (15^\circ C\sim 28^\circ C) and the water stressed or not, was conditioned of to the inoculation with the BIL to the test varieties in seedling stage. In low temperature, most of the varieties were more infected with blast, however the Indica-Japonica hybrids were more infected in high temperature conditions. The water stressed was more infected with blast than the not stressed. The interaction of variety with water stress was not so much as that of variety with temperature. Resistant reaction to blast (BIL) was not affected by the temperature and water stress, but the moderately resistant or susceptible one was much affected by them. Inoculum of BIL was virulent to the newly bred Indica-Japonica hybrid cultivars such as Tongil, Nopung, etc, but not virulent to the Japonica cultivars such as Nongbaek, Jinheung, etc. The discrete, mixed or variable lesions were observed mainly in the moderately resistant or susceptible cultivars such as Kanto 51, Yashiromochi, Ishikari-shiroke, etc.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.2
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• pp.236-246
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• 1997

This study was conducted to obtain the basic information of edible resources among plant species. Potentials of resource plants were important in various usages, healthy food, medicinal materials, and breeding materials. Through our investigation 609 species of resources plants were considered as edible resources. These species belong to 74 families in which Asteraceae, Poaceae, Fabaceae, and Rosaceae were major families. Brassicaceae, Liliaceae, and Asteraceae contained large numbers of edible plants because plants belonged to these families were mainly used as vegetable. But Cyperaceae and Poaceae had relatively small numbers of species in the category of edible plant because plants belonged to these families have not been used directly as vegetables, common usage of edible plant. But Poaceae have a potentials as genetic donor for resistance-breeding strategies in major cereals. Although Poaceae can not be used as food directly, Poaceae should be investigated intensely in future for improvement of major cereals or application as fodder plants. The beneficial traits of edible plants as breeding materials have not been studied yet and development of new crop from plant resources requires the information about current situation in occurrence of resources plants genetically related to current crop species. Our results do not cover all plant species in Korea but this classification and identification about edible resources will provide primary information about plant resources. The collected seeds of resource plants showed wide spectrum in germination rate among plant species. The germination rate would probably be affected by collecting times, collected stage, and stored period. The proper methods about improving germination rate have to be elucidated to propagate the resource plants.

• Development and Reproduction
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• v.22 no.1
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• pp.55-64
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• 2018

Previous studies showed that recombinant equine chorionic gonadotropin ($rec-eCG{\beta}/{\alpha}$) exhibits both follicle-stimulating hormone (FSH) and luteinizing hormone (LH)-like activities in rat LHR- and FSHR-expressing cells. In this study, we analyzed signal transduction by eelFSHR and eelLHR upon stimulation with $rec-eCG{\beta}/{\alpha}$ and native eCG. The cyclic adenosine monophosphate (cAMP) stimulation in CHO-K1 cells expressing eelLHR was determined upon exposure to different doses (0-1,450 ng/mL) of $rec-eCG{\beta}/{\alpha}$ and native eCG. The $EC_{50$ values of $rec-eCG{\beta}/{\alpha}$ and native eCG were 172.4 and 786.6 ng/mL, respectively. The activity of $rec-eCG{\beta}/{\alpha}$ was higher than that of native eCG. However, signal transduction in the CHO PathHunter Parental cells expressing eelFSHR was not enhanced by stimulation with both agonist $rec-eCG{\beta}/{\alpha}$ and native eCG. We concluded that $rec-eCG{\beta}/{\alpha}$ and native eCG were completely active in cells expressing eelLHR, similar to the activity in the mammalian cells expressing LHRs. However, $rec-eCG{\beta}/{\alpha}$ and native eCG did not invoke any signaling response in the cells expressing eelFSHR. These results suggest that eCG has a potent activity in cells expressing eelLHR. Thus, we also suggest that $rec-eCG{\beta}/{\alpha}$ can induce eel maturation by administering gonadotropic reagents (LH), such as salmon pituitary extract.

• The Journal of the Korea Contents Association
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• v.13 no.9
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• pp.305-311
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• 2013

This study analyzed the oral status after recording the images by using QLF-D with targets of 38 youth people with hearing impairment and hearing language impairment. In order to investigate the state of oral hygiene, plaque index (O'Leary index) and contents of investigation of the state of the teeth included the number of sound teeth, the number of caries teeth, dental caries experience and the number of filling teeth. The following results were obtained. First, women lacked the management on plaque and had more caries teeth compared with men. In terms of impairment classification, subjects with both hearing and language impairment lacked the management on plaque and had more caries teeth. Second, subjects who did not get an oral exam for one year had more caries teeth. Oral hygiene score was the highest with the brushing time for 3-4 minutes. The number of sound teeth was increased as the brushing time was increased. In addition, the oral hygiene management time was the highest when cleaning the teeth, gums and tongue at the same time. Third, it was shown that the satisfaction of oral health education by using the new equipment was high. As a result of this study, in order to improve the oral health level of impaired students, they shall be trained to manage their teeth by themselves and educated to increase their motivation and practice. Thus, it is thought that various approaches which are differentiated from existing methods are required to be tried.

• Microbiology and Biotechnology Letters
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• v.43 no.4
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• pp.322-329
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• 2015

The effects of water extracts of Gallus gallus var. domesticus (Yeonsan ogolgye, GD) on the activities of osteoblast differentiation and the restraint of osteoclast formation were investigated. The water extract of GD in the human osteoblast "MG-63" cell, was examined in relation to alkaline phosphatase (ALP) activity and alizarin red stains. In order to observe the effects of osteoclasts formation, we analyzed RAW 264.7 cell tartrate-resistant acid phosphatase (TRAP) activity and TRAP stains. The ALP activity of the water extract of hen and cock flesh (3 years) were 133.8% and 129.6%, respectively. The ALP activity of flesh extracts was also higher than that of the skin extracts. Concerning the effects of age, the 3 years old flesh extracts had a higher activity than that of the one year old extracts. However the activity of the 3 years old skin extracts was lower than that of the one year old extracts. For gender conditions, the ALP activity of the hen extract was higher than that of the cock. The degree bone mineralization in the three years old hen flesh exhibited the highest rate, at 124.3%, amongst all the groups. The TRAP activity of the flesh extracts of the three years old cock revealed the lowest rate, at 31.8%, compared to the control. Our results demonstrate that the water extract of GD increases bone mineralization and osteoblast differentiation activity in MG-63 cells and enhances the inhibitory activity of bone-resorption in RAW 264.7 cells. In conclusion, the water extracts of GD seem to be effective in the prevention and treatment of bone related disorders.

• Microbiology and Biotechnology Letters
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• v.42 no.1
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• pp.18-24
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• 2014

This study was conducted to investigate optimum conditions for the production of cellulose-degrading crude enzymes by an isolated marine bacterium. A marine microorganism producing an extracellular cellulose-degrading enzyme was isolated from the red seaweed, Grateloupia elliptica Holmes. The isolated bacterium was identified as Cellulophaga lytica by 16S ribosomal RNA gene sequence analysis and physiological profiling and designated as Cellulophaga lytica PKA 1005. The optimum conditions for the growth of Cellulophaga lytica PKA 1005 were pH 7, 2% NaCl, and $30^{\circ}C$ with 36 h incubation time. To obtain the crude enzyme, the culture medium of the strain was centrifuged for 30 min at $12,000{\times}g$ and $4^{\circ}C$, and the supernatant was used as crude enzyme. The optimum conditions for the production of the cellulose-degrading crude enzyme were pH 8, $35^{\circ}C$, 8% carboxyl methyl cellulose, and 60 h reaction time.

• Microbiology and Biotechnology Letters
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• v.42 no.2
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• pp.139-144
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• 2014

This study examined the efficacies of Cynanchum wilfordii and Phlomis umbrosa extracts on serum insulin like growth factor-I (IGF-I) and bone growth by raising rats in vivo. C. wilfordii and P. umbrosa extracts significantly increased serum IGF-I by 42% and 22% than the control, respectively. Treatment with ${\alpha}$-amylase when manufacturing these extracts remarkably increased the concentration of IGF-I by 63% and 36% above the control, respectively. This meant that these extracts, especially ${\alpha}$-amylase treated extracts, maintained a higher level of IGF-I secretion in the treated groups. In addition, increases of 6% in femur length were found after 8 weeks of oral administration with these extracts. These results indicate that C. wilfordii and P. umbrosa extracts have beneficial effects on bone growth via IGF-I.

• Journal of Microbiology and Biotechnology
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• v.18 no.7
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• pp.1290-1297
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• 2008

To investigate the diversities of Accumulibacter phosphatis and its polyhydroxyalkanoate (PHA) synthase gene (phaC) in enhanced biological phosphorus removal (EBPR) sludge, an acetate-fed sequencing batch reactor was operated. Analysis of microbial communities using fluorescence in situ hybridization and 16S rRNA gene clone libraries showed that the population of Accumulibacter phosphatis in the EBPR sludge comprised more than 50% of total bacteria, and was clearly divided into two subgroups with about 97.5% sequence identity of the 16S rRNA genes. PAO phaC primers targeting the phaC genes of Accumulibacter phosphatis were designed and applied to retrieve fragments of putative phaC homologs of Accumulibacter phosphatis from EBPR sludge. PAO phaC primers targeting $G_{1PAO},\;G_{2PAO},\;and\;G_{3PAO}$ groups produced PCR amplicons successfully; the resulting sequences of the phaC gene homologs were diverse, and were distantly related to metagenomic phaC sequences of Accumulibacter phosphatis with 75-98% DNA sequence identities. Degenerate NPAO (non-PAO) phaC primers targeting phaC genes of non-Accumulibacter phosphatis bacteria were also designed and applied to the EBPR sludge. Twenty-four phaC homologs retrieved from NPAO phaC primers were different from the phaC gene homologs derived from Accumulibacter phosphatis, which suggests that the PAO phaC primers were specific for the amplification of phaC gene homologs of Accumulibacter phosphatis, and the putative phaC gene homologs by PAO phaC primers were derived from Accumulibacter phosphatis in the EBPR sludge. Among 24 phaC homologs, a phaC homolog (GINPAO-2), which was dominant in the NPAO phaC clone library, showed the strongest signal in slot hybridization and shared approximately 60% nucleotide identity with the $G_{4PAO}$ group of Accumulibacter phosphatis, which suggests that GINPAO-2 might be derived from Accumulibacter phosphatis. In conclusion, analyses of the 16S rRNA and phaC genes showed that Accumulibacter phosphatis might be phylogenetically and metabolically diverse.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.3
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• pp.189-194
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• 2012

In this study, a 3-stage biological aerated filter (BAF) system was proposed to enhance nitrogen removal in the treatment of low carbon to nitrogen ratio (C/N ratio) municipal wastewater. Laboratory experiments were conducted to evaluate the effects of dynamic-flow at the HRT of 6 h. Results of the long-term operation of 3-stage BAF systems showed that the dynamic-flow enabled the total nitrogen removal (T-N) removal efficiency of the system to be about 7 % higher than that of non-dynamic-flow system in treating domestic wastewater due to the more efficient use of organic substrates. The overall $NH_4$-N removal performance was stable during the operational period due to the unique system configuration where independent nitrification occurred. It was concluded that the 3-stage BAF system proposed in this study provided excellent performance in the removal of nitrogen by employing dynamic-flow and three columns functioning as sorption, denitrification and nitrification, respectively.