• Korean Journal of Plant Resources
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• v.21 no.2
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• pp.111-116
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• 2008

This study was carried out to induce plant regeneration via multiple shoot formation from sucker explants of Rubus fruticosus L. ${\times}$ R. parvifolius L. To induce adventitious shoots, the sucker explants were sterilized in 1.2% sodium hypochlorite (NaOCl) solution, and then were cultured on the full and 1/2 MS solid medium supplemented with BA (0.1, 0.5, 1.0, $2.0mg{\cdot}L^{-1}$). After 4 weeks of culture, the highest frequency (83.3%) of shoot formation from sucker explants was obtained from the full MS medium with $1.0mg{\cdot}L^{-1}$ BA. The highest shoot number (3.7) per explant was obtained from the full MS medium with $0.5mg{\cdot}L^{-1}$ BA. After 12 weeks of culture, the number of shoots (15.4) per explant was increased. The highest frequency (95%) of root formation was obtained from the 1/2 MS medium, when the explant with shoot were cultured on the full, 1/2 and 1/4 MS medium. The survival rate of the plantlets after transfer to plastic pots containing sand, soil, and vermiculite (1.1:1, vol.) was 95%. The results indicate that multiple shoot procedure can be applied for an efficient mass propagation of Rubus fruticosus L. ${\times}$ R. parvifolius L.

• Horticultural Science & Technology
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• v.30 no.2
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• pp.152-157
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• 2012

We investigated the effect of 1-methylcyclopropene (1-MCP) on ethylene production induced by simulated transport stress in $Begonia$ ${\times}$ $hiemalis$ 'Blitz' and 'Carnival' to improve the display life in potted plants. The simulated transportation conditions were imposed for 4 days in simulated export containers with darkness, vibration with continuous shaking ($150{\pm}20$ rpm) on a rotary lab shaker, and low temperature ($12^{\circ}C$). Plants were treated with 1-MCP at three concentrations (5, 25, or 125 $nL{\cdot}L^{-1}$) and for three different periods (0, 6, or 12 hours) before undergoing the simulated transport stress treatments. Treatment with 25 or 125 $nL{\cdot}L^{-1}$ 1-MCP inhibited the abscission of open flowers by more than 40% as compared to the untreated plants. One week after the treatments, the ethylene production decreased in the plants treated with 125 $nL{\cdot}L^{-1}$ 1-MCP for 'Blitz' and 25 $nL{\cdot}L^{-1}$ for 'Carnival'. Ethylene production was correlated with concentration and duration of 1-MCP treatment in 'Blitz', but not in 'Carnival'. To reduce flower abscission and ethylene production, thus improve the display life when plants are exposed to transportation stress, we recommend pre-treatment with 1-MCP before packaging, using concentrations and durations specific to each cultivar, 125 $nL{\cdot}L^{-1}$ for 6 h and 25 $nL{\cdot}L^{-1}$ for 12 hours for 'Blitz' and 'Carnival', respectively.

• Korean Journal of Plant Tissue Culture
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• v.27 no.3
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• pp.169-173
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• 2000

A 1,183bp cDNA, AmA1, encoding the seed storage protein of Amaranthus hypochondriacus was isolated by reverse transcriptase-polymerase chain reaction (RT-PCR) and characterized. AmA1 gene was subcloned into plant binary vector under Cauliflower Mosaic Virus (CaMV) 35S promoter and nopaline synthase terminator (3'NOS). The recombinant binary vector was used to transform Nicotiana tabacum using Agrobacterium tumefacien -mediated transformation procedure. Shoots were induced on MS medium with 0.1 mg/L NAA, 1.0 mg/L BA, 100 mg/L kanamycin and 250 mg/L cefotaxime. Transgenic plants were selected on rooting medium based on MS medium containing 200 mg/L kanamycin and 250 mg/L cefotaxime without phytoregulators. The presence of AmA1 gene in the transgenic plants was confirmed by PCR followed by DNA hybridization. The expression of AmA1 gene in the transgenic plant was observed by RT-PCR method.

• KSBB Journal
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• v.22 no.4
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• pp.201-206
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• 2007

The demand of L-arabinose has been increased recently because of its advantages including clinical effect. L-arabinose can be produced from dilute acid hydrolysis of agricultural wastes. In this study, optimum conditions of L-arabinose production using dilute acid hydrolysis of agricultural wastes and nutshells were determined. Among the tested various agricultural wastes and nutshells, corn fiber was selected as the best raw material for the production of arabinose. The highest arabinose production was achieved an acid hydrolysis of corn fiber for 1 h at 130$^{\circ}C$ with 0.4% sulfuric acid. Above optimal conditions, it was obtained 20.1 g/L glucose, 10.1 g/L xylose, 7.8 g/L arabinose and 1.8 g/L galactose from 90 g/L of corn fiber. For the purification of arabinose, it was carried out to remove all of sugars except arabinose by the Candida tropicalis cultivation of acid hydrolyzate and an organic contaminants such as pigments by the active carbon treatment of fermentation broth. Moreover, experiments were carried out to eliminate an ions by exchange chromatography. Finally, we obtained 3.1 g of partially purified L-arabinose powder with about 40% yield by evaporation and vacuum drying.

• Bulletin of the Society of Naval Architects of Korea
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• v.7 no.1
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• pp.37-44
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• 1970

The plate under shear loading umformly distributed on the end portions of its side boundary was considered. Infinite hyperbolic serieses and Fourier serieses were combined as a stress function and from which exact solutions for the 15 cases for the parameters of b/L=0.25, 0.5, 1.0 and l/L=0.2, 0.4, 0.6, 0.8, 1.0 are obtained. In each cases the first 5 terms of the infinite series at the 36 points as shown in Fig. 3. The results are presented in Fig. 4-1, 4-2, and 4-3. The conclusions are as follows: 1) The stresses ${\sigma}_x$ increase very slightly as $\chi$ increases in the range of 0<x<L-l 2) When the parameters satisfy the conditions b/L<0.25 and l/L<0.2, the stresses in the region of 0<x<L-l can be obtained by replacing the uniform shear loading by the equivalent uniform shear loading by the equivalent uniform tensile force and pure bending moment at x=l. 3) The stress ${\sigma}_y$ is negligible throughout the region. 4) When the parameter b/L varies, the stresses ${\sigma}_x$ and u vary as L/b, while strain $\upsilon$ varies as $(L/b)^2$.

• KSBB Journal
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• v.17 no.2
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• pp.162-168
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• 2002

Human ferritin H- and L-chain genes(hfH and hfL) were cloned into the yeast shuttle vector YEp352 with various promoters, and the vectors constructed were used to transform Saccharomyces cerevisiae 2805. Three different promoters fused to hfH and hfL were used: galactokinase 1 (GAL1) promoter, glyceraldehyde-3-phosphate dehydrogenase(GPD) promoter and alcohol dehydrogenase 1(ADH1 ) promoter. SDS-polyacrylamide gel electrophoresis and Western blotting analyses displayed expression of the introduced hfH and hfL. In the production of both ferritin H and L subunits GAL1 promoter was more effective than GPD promoter or ADH1 promoter. Ferritin H and L subunits produced in S. cerevisiae were spontaneously assembled into its holoproteins as proven on native polyacrylamide gels. Both recombinant H and L-chain ferritins were catalytically active in forming iron core. When the cells were cultured in the medium containing 10 mM ferric citrate, the cell-associated concentration of iron was 174.9 $\mu\textrm{g}$ Per gram(dry cell weight) for the recombinant yeast YG-L and 148.8 $\mu\textrm{g}$ Per gram(dry cell weight) for the recombinant yeast YG-L but was 49.4 $\mu\textrm{g}$ Per gram(dry cell weight) in the wild type, indicating that the iron contents of yeast is improved by heterologous expression of human ferritin H-chain or L-chain genes.

• Journal of Plant Biotechnology
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• v.32 no.2
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• pp.123-128
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• 2005

A series of experiments were performed to establish regeneration system through friable embryogenic callus (FFC) of Lilium longiflorum 'Nellie White'. Only hard and regular callus was induced from bulb scales on medium containing 2.0 mg/L dicamba and $30{\sim}90$ g/L sucrose. The induced hard callus was subcultured on medium with 2.0 mg/L dicamba and 30 g/L sucrose, and used as a material for induction of FEC. In order to induce FEC, induced hard and regular callus was chopped into $1{\sim}2\;mm$ segments, and re-cultured on medium with 2.0 mg/L dicamba and 90 g/L sucrose. FEC was induced from chopped hard calli by the subcultures of two months interval. The induction rate of FEC was enhanced when hard callus was subcultured on same medium. FEC was proliferated more than 5 times on medium with $1.0{\sim}2.0\;mg/L$ dicamba and 90 g/L sucrose. Bulblet differentiation from FEC was very favorable on MS medium supplemented with 0.1 mg/L BA, 1.0 mg/L NAA and 30 g/L maltose, but many differentiated bulblets were changed to vitrificated ones. The differentiation of normal bulblets was most effective on medium containing $0.5{\sim}1.0\%$ activated charcoal and 30 g/L sucrose.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10a
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• pp.545-547
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• 2000

본 논문은 영역별 근접 그래프(geographic nearest neighbor graph)와 레인지 트리(range tree)를 이용하여 평면 위의 n 개의 점에 대한 L$\infty$(L1) 거리(metric) 상의 디루니 삼각분할(Delaunay triangulation)을 구축하는 방법을 소개한다. 이 방법은 L$\infty$(L1) 거리상에서 디루니 삼각분할에 있는 각 삼각형의 최소한 한 선분이 영역별 근접 그래프에 포함됨을 이용하여 레인지 트리 방법으로 디루니 삼각분할을 구축한다. 본 방법은 O(nlogn)의 순차계산 시간에 L$\infty$(L1) 디루니 삼각분할을 구축하며, CREW-PRAM (Concurrent Read Exclusive Write Programmable Random Access Machine)에서 O(n)의 프로세서로 O(logn)의 병렬처리 시간에 L$\infty$(L1) 디루니 삼각분할을 구축한다. 또한, 이 방법은 직선간의 교차점 계산 대신 거리비교를 하기 때문에 수치오차가 적고 구현이 용이하다.

• Journal of Bio-Environment Control
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• v.11 no.2
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• pp.74-80
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• 2002

The effect of the foliar application of amino acid mixture on the growth of melon (Cucumis melo L.) seedlings was investigated. The amino acid treatments were initiated at the first (Ll) or second (L2) fully expanded leaf stage. The concentrations of amino acid mixture used were 0,10, 20, and 30 mg . L$^{-1}$ . At Ll stage, the fresh and dry weights of shoot were high in the amino acid treatments. Plant height was the highest in 30 mg . L$^{-1}$ at the third sampling of Ll. At L2 stage, shoot fresh weight was the greatest when the concentration of amino acid mixture was 30 mg.L$^{-1}$ at the third sampling. Plant height was the highest in 30 mg L$^{-1}$ at the second and third samplings. At the third sampling of Ll stage the amino acid mixture affected leaf length and leaf width of the first true leaf. At the third sampling of L2 stage leaf length was not significantly dirtferent between treatments, while leaf width was greater in amino acid treatments. At the second and third samplings of Ll stage the amino acid mixture had effect on leaf length and leaf width of the second true leafs which were not significantly different between treatments at L2 stage. Leaf length and leaf width of the third true leaf were affected by amino acid treatments. In conclusion, when the first true leaf expanded\ulcorner three foliar applications of 20-30 mg . L$^{-1}$ amino acid mixture can stimulate the growth of melon seedlings. If the amino acid mixture is sprayed at the second true leaf stage, two foliar applications of 30 mg . L$^{-1}$ amino acid mixture can improve the growth of melon seedlings.

• Microbiology and Biotechnology Letters
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• v.30 no.1
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• pp.63-67
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• 2002

Bifidobacterium strain was isolated from the feces of brast fed infants. The isolated strain was identified as Bifidobacterium longum by 16S rRNA sequence analysis and named as Bifidobacterium SH2. The MRS medium was modified to obtain high density cells of Bifidobacterium SH2. The optimal medium was determined to be 50 g/L lactose, 10 g/L beef extract, 10 g/L peptone, 5 g/L yeast extract, 7 g/L sodium acetate, 2 g/L ammonium citrate, 2 g/L disodium phosphate,1 g/L tween 80, 0.2 g/L MnSO$_4$ and 0.5 g/L L-cysteine. The pH and temperature were optimized as 5.0 and $37^{\circ}C$, respectively. Through out the optimization of medium composition and culture conditions, the dry cell weight and viable cell count were 2.5 times and 1.8 times higer than those in MRS medium, respectively.