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        검색결과 9,514

        8422.
        2009.03 KCI 등재 서비스 종료(열람 제한)
        Lactobacillus sp., Acetobacter sp. and yeast were the most dominant organisms in the EM stock culture and subculture product. Lactic acid bacteria and yeast were able to grow in the fermentation process utilizing seawater. EM treatment of higher concentrations using EM stock culture and EM clay balls (1% or 4%) contributed to an early removal of malodor and an increase of DO in the polluted sediments, indicating an odor-removing activity of EM. The EM treatment of higher concentrations (1% or 4%) somewhat appeared to modify the microbial communities within the sediments, which was confirmed by existence of a few unique fragments from the stock culture based on PCR-DGGE. It still remains to be elucidated that EM cultures were directly involved in the malodor removal and potential sediment bioremediation.
        8423.
        2009.03 KCI 등재 서비스 종료(열람 제한)
        Recently, giant embryonic rice and functional rice food are preferred by more consumers, which are attributed to the fact that the embryo has high concentrations of essential amino acids, fatty acids, and vitamins relative to other parts of rice grains. In this report, the heredity and stability of giant embryo mutations in successive generations were analyzed regarding a giant embryonic line, 'P47', induced by T-DNA insertion and a F2 population from a cross between 'P47' and 'Junam'. The mutant lines with increases of 1.5, 1.7 and 1.8 times on embryo length, width and 100-embryo weight to those of the control showed stable inheritance across three generations. The continuous frequency distributions of embryo size in the F2 population showed that the embryo size is a quantitative trait of polygene controlled. In addition, wide range of transgressive segregations of six traits affecting embryo size confirmed exchange of genetic materials and recombination between genes controlling embryo size. Five giant embryo mutant lines selected from the F2 population will be used for artificial selection and improvement of giant embryonic varieties.
        8426.
        2009.02 KCI 등재 서비스 종료(열람 제한)
        This study carried out development of a natural antimicrobial agent from Schima wallichii ssp. liukiuensis. Compound I exhibiting potent antimicrobial activity against Candida spp. was isolated from the methanol extracts of Schima wallichii ssp. liukiuensis. The structure of I identified as a sterol glycoside consisted of a trisaccharide and α1-sitosterol. Trisaccharide composed of L-rhamnose, D-galactose and D-glucose residues. The antimicrobial activity of I was selective on yeast rather than bacteria or other fungi. Compound I was demonstrated to be ineffective against toxicity to mouse liver cells where as protective to human dermal fibroblast cells at low concentrations. Thus, it is reasonable to expect a sterol glycoside (I) as a valuable alternative for synthetic antifungal.
        8427.
        2009.01 서비스 종료(열람 제한)
        The cloning of canids was succeeded in 2005, several years after the birth of Dolly the sheep and also after the cloning of numerous other laboratory and farm animal species. The delay of successful somatic cell nuclear transfer (SCNT)was due to the unique reproductive characteristics of the female dogin comparison to other domestic mammals, such as ovulation of immature canine oocyte and a requirement of 25 days for the completion of meiosis within the oviduct (Holst & Phemister, 1971). When the technology for the recovery of in vivo matured oocyte was established, the application of cloning also became possible and cloned dog offspring were obtained. This report summarizes the progress of technical procedures that are required for cloning canids and the application of this technique. The first cloned dog, Snuppy, was achieved using an in vivo-matured oocyte which was enucleated and transferred with an adult skin cell of male Afghan hound. After establishment of a criterion of well-matured oocyte for the improvement of SCNT efficiency, we obtained three cloned female Afghan hound and a toy poodle cloned from 14 year-old aged Poodle using SCNT through this factor. To date, cloned dogs appeared to be normal and those that have reached puberty have been confirmed to be fertile. Through application of canine SCNT technique, first, we demonstrated that SNCT is useful for conserving the breed of endangered animal from extinction through cloning of endangered gray wolves using inter-species SCNT and keeping the pure pedigree through the cloning of Sapsaree, a Korean natural monument. Secondly, we showed possibility of human disease model cloned dog and transgenic cloned dog production through cloning of red fluorescent protein expressing dog. Finally, SCNT can be used for the propagation of valuable genotypes for making elite seed stock and pet dog. In summary, dog cloning is a reproducible technique that offers the opportunity to preserve valuable genetics and a potential step towards the production of gene targeted transgenic cloned dogs for the study of human diseases.
        8428.
        2008.12 KCI 등재 서비스 종료(열람 제한)
        Freshly harvested seed of Chinese milk vetch (Astragalus sinicus L.; CMV) was strongly dormant because of hardseedness. Seeds of freshly harvested germinated only 8% while clipping the seed coat completely overcome the innate dormancy, which indicates inhibition of germination of the seed is mainly due to seed coat (87%). The dormant (intact) hard seeds did not imbibe water whereas the non-dormant (clipped) seeds took up rapidly. In natural environment condition, the hard seed coat dormancy was broken only after 5 months after seed harvest. To break such a strong seed coat dormancy, the chemical and heat treatments were effective. Concentrated sulfuric acid was more effective than dry heat and hot water treatments. Hot water treatment improved germination but the germination percentage was less than 41%. Treatments increased germination due to its effect on the seed coat integrity. A scanning electron microscope reveled that disruption of seed coat layers and subsequent development of numerous crack in the hilum region of the seed and on the seed coat surface of concentrated sulfuric acid treatment and formation of cracks in the dry heat treatments, respectively, were observed in the seed coat surface, which served as water entry points.
        8429.
        2008.12 KCI 등재 서비스 종료(열람 제한)
        The cultivation of green manure crop is considered as a good management practice by increasing soil organic matter and fertility levels. This experiment was conducted to improve the soil environment under rice-based cropping system at paddy soil (fine loamy, mixed, nonacid, mesic, family of Aeric Fluventic Haplaquepts) in National Institute of Crop Science (NICS), Korea in 2006 to 2007. The variation of soil temperature in green manure plots was lower than without green manure (control) during spring season (April to May). The temperature variation of no tillage plot (broadcast before rice harvest) was the lowest among treatments. After green manure cropping, the soil bulk density and porosity ratio were improved at the top soil. The production of green manure was the highest athairy vetch and barley mixture plot by partial tillage. However, mixture treatment had no improvement on soil organic matter. After rice cropping with green manure application, soil quality was improved such as soil physical properties except mixture treatment. Therefore, we suggest that soil quality should be improved by green manure cultivation under rice-based cropping system.
        8430.
        2008.12 KCI 등재 서비스 종료(열람 제한)
        2003년에 이상적으로 많이 발생하여 벼에 심각한 피해를 가져온 혹명나방의 재배방법별, 엽록소 함량별 피해실태를 조사하여 피해에 따른 수량반응, 미질변화 등을 구명하고자 조사한 결과는 다음과 같다. 1. 혹명나방의 피해가 심할수록 벼의 등숙비율, 천립중의 감소와 복백립 등 미숙립의 증가에 따른 완전미 비율이 감소되어 완전미 수량이 피해가 심한 곳에서 36% 감소되었다. 2. 혹명나방의 피해가 심할수록 쌀의 외관상 품위가 떨어질 뿐만 아니라 단백질함량이 높아져 식미치는 감소되어 미질이 급격히 저하되었다. 3. 질소질 비료의 시용량이 증가할수록 혹명나방에 의한 피해는 증가하였으며, 특히 주남벼의 경우 질소량이 증가할수록 피해가 급증하였다. 4. 질소 시비량이 추천 시비량인 11 kg/10a를 초과시 피해엽율이 60% 이상으로 급증하였고, 60% 이상 피해를 입은 엽의 비율도 25%이상으로 늘어나 수량 감수 요인으로 작용하였다.
        8431.
        2008.12 KCI 등재 서비스 종료(열람 제한)
        Sensing performances of evanescent field absorption (EFA) hetero-core fiber sensor has been presented based on EFA by changing the length and the core diameter of the single mode fiber. Experimental results have demonstrated a good feature in their relationship between the length and the core diameter of the single mode fiber. The sensor consists of 2 fiber optics which have the same cladding diameter of 125μm However one fiber optic used is single mode and has varying core diameter ranging from 3.3 to 5.6μm. The other fiber is multimode type and has a thicker fixed core diameter of 62.5μm. The 2 fiber optics are thermally spliced together. Experiments conducted to measure the resonance wavelength were carried out over a range of refractive index, to find the optimum sensing length Experiments show that core diameter of the single mode fiber and sensing length offects the linearity and sensitivity.
        8432.
        2008.12 KCI 등재 서비스 종료(열람 제한)
        We have proposed and demonstrated an gas-flow sensor using optical fiber bragg grating(FEG). The flow sensor has no electronics and no mechanical parts in its sensing part and the structure is th11s simple and immune to electromagnetic interference(EMI). The FEG sensor was consisted qf the sensing element and a coil heater. The metal coil was used to supply the current to the FEG. While some currents supply to the coil, the refractive index of the FEG under the coil is changed and thus the wavelength shift of fiber optic sensor was induced In this work, the wavelength shift according to flow-rate was experimentally studied and was used to evaluate the gas flow-rate in a gas tube. As a result, it was possible to measure the flow-rate in a linear range from 5 to 20l/min with a resolution of approximately 1l/min at the applied currents of 100 mA and 120 mA. The measured sensitivities were 15.3 pm/l/min for 100 mA and 20.2 pm/l/min for 120 mA.
        8433.
        2008.12 KCI 등재 서비스 종료(열람 제한)
        In the sea various methods have been conducted to capture wave energy which include the use of pendulums, pneumatic devices, etc. Floating devices, such as a cavity resonance device take advantages of both the water motion and the wave induced motions of the floating body itself. The wave energy converter is known commercially as the WAGB(Wave Activated Generator Buoy) and is used in some commercially available buoys to power navigation aids such as lights and horns. This wave energy converter consists of a circular flotation body which contains a vertical water column that has free communication with the sea. A theoretical analysis of this power generated by a pneumatic type wave energy converter is performed and the results obtained from the analysis are used for a real wave energy converter buoy. This paper is shown to have an optimum value for which maximum power is obtained at a given resonant wave period Also, the length of the internal water column corresponds to that of the water mass in the water column. If designed properly, wave energy converter can take advantage not only of the cavity resonance, but also qf the heaving motion of the buoy. Finally, simulation is performed with a LabVIEW program and the simulation results are applied to a wave energy simulator for modifying design data for a wave energy converter.
        8435.
        2008.12 KCI 등재 서비스 종료(열람 제한)
        8436.
        2008.12 KCI 등재 서비스 종료(열람 제한)
        Sustainable development is a key issue in the 21st Century and ecotourism is an alternative area of sustainable development. Ecotourism marketing is also a part of societal marketing which emphasizes social contributions. This study investigated the factors which affected ecotourist satisfaction and behavioral intentions. The sample for this study was composed of 212 ecotourists who visited the Upo area. This is one of the most well-known educational ecotourism sites in Korea and it has been registered at the Ramsar Convention for the conservation of wetlands since 1998. This study demonstrated that expectation factors did not significantly influence satisfaction. Second, the performance factors of physical attributes, eco-interpretation, eco-experience, and usability did significantly influence satisfaction. Third, the expectation factor of accessibility was significantly related to disconfirmation. Fourth, all performance factors significantly influenced disconfirmation. Fifth, it was found that disconfirmation significantly influenced satisfaction. Finally, satisfaction significantly influenced the intention to revisit and recommend the site to others. Managerial implications and future studies are discussed.
        8438.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        We evaluated the anti-allergic effect of black colored rice (Oryza sativa L.) and its main constituents, cyanidin 3 glucoside (C3G) and cyanidin (Cy) on scratching behavior in mice. The black rice extract (BRE) and its constituts inhibited the scratching behavior induced by compound 48/80 and histamin. To understand the role of intestinal microflora in the anti-allergic effect of C3G, which was suspected to play a key role in depressing scratching behavior, C3G was incubated with human fecal bacteria. Protocatechuic acid (PCA) was found within the 30 min and its concetration sharply increased. Vanillic acid (VA) was also detected in the incubated sample mixture. The anti-allergic effect of these compounds, C3G, Cy, PCA and VA, were investigated. PCA and Cy potentely reduced scratching behavior in mice induced by compound 48/80 and histamin. These findings enable us to conclude that intestinal bacterial metabolites, PCA and VA, produced by intestinal micro flora contributed to suppressing the scratching behavior induced by compound 48/80 and histamin.
        8439.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        Iris nertschinsk has been used generally as a decorative plant. However, it has been almost used as a medicine for therapy on various human diseases. In this study, we demonstrate the anti-tumor effect of Iris nertschinsk on human breast cancer cells. Firstly, we found that Iris nertschinsk dose-dependently induced cell death in human breast cancer cell lines, MCF7 and MDA-MB231. Moreover, phosphorylation of p53 was induced after Iris nertschinsk treatment in MCF7 cells, which has a functional p53, but not in MDA-MB231 cells, which has a dysfunctional p53. We next examined whether Iris nertschinsk induces caspase-dependent cell death. Caspase-7 was cleaved after Iris nertschinsk treatment in MCF7 cells. Interestingly, either caspase-3 or caspase-7 was cleaved in MDA-MB231 cells that p53 had been phosphorylated by Iris nertschinsk treatment, indicating that Iris nertschinsk induces apoptosis through the cleavage of caspase-3, -7 in human breast cancer cell lines, MCF7 and MDA-MB231, but related to the status of p53. Therefore, these results suggest that Iris nertschinsk could be used as a treatment for human breast cancer. This research is supported by National Institute of Agricultural Biotechnology research grant.
        8440.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to develop the EEG (Euchromatin Enriched Genomic) DNA library of wheat, barley, rye and oat. Mcr A and Mcr BC system in DH5 alpha bacteria cell line and Kuemkangmil, Olbori, Olhomil and Olgwiri were used for materials in our experiments. EEG colonies have been constructed by using junk DNA exclusion. We analyzed the genetic information of the colonies using blast searches of NCBI and GRAMENE web sites. One hundred eighty-four, 65, 79 and 119 STS primer pairs were developed using sequencing data of selected colonies in Kuemkangmil, Olbori, Olhomil and Olgwiri respectively. Twenty-eight and forty-two percent of designed primer pair showed polymorphism using six endoucleases in Kuemkangmil, Olbori, Olhomil and Olgwiri germplasm respectively. These primers could be useful for specific allele tagging in mapping populations and germplasm and for the study of functional genomics of wheat, barley, rye and oat.