• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.12
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• pp.4725-4747
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• 2020

Software defined networking (SDN) is considered to be one of the most promising paradigms in the future. To solve the scalability and performance problem that a single and centralized controller suffers from, the distributed multi-controller architecture is adopted, thus forms multi-domain SDN. In a multi-domain SDN network, it is of great importance to ensure a reliable control plane. In this paper, we focus on the reliability problem of multi-domain SDN against controller failure from perspectives of backup controller deployment and controller replication. We firstly propose a placement algorithm for backup controllers, which considers both the reliability and the cost factors. Then a controller replication mechanism based on shared data storage is proposed to solve the inconsistency between the active and standby controllers. We also propose a shared data storage layout method that considers both reliability and performance. Besides, a fault recovery and repair process is designed based on the controller backup and shared data storage mechanism. Simulations show that our approach can recover and repair controller failure. Evaluation results also show that the proposed backup controller placement approach is more effective than other methods.

• The Plant Pathology Journal
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• v.36 no.3
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• pp.280-288
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• 2020

RNA interference (RNAi) has attracted attention as a promising approach to control plant viruses in their insect vectors. In the present study, to suppress replication of the rice stripe virus (RSV) in its vector, Laodelphax striatellus, using RNAi, dsRNAs against L. striatellus genes that are strongly upregulated upon RSV infection were delivered through a rice leaf-mediated method. RNAi-based silencing of peroxiredoxin, cathepsin B, and cytochrome P450 resulted in significant down regulation of the NS3 gene of RSV, achieving a transcriptional reduction greater than 73.6% at a concentration of 100 ng/μl and, possibly compromising viral replication. L. striatellus genes might play crucial roles in the transmission of RSV; transcriptional silencing of these genes could suppress viral replication in L. striatellus. These results suggest effective RNAi-based approaches for controlling RSV and provide insight into RSV-L. striatellus interactions.

• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.56.2-56.2
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• 2007

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• BMB Reports
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• v.29 no.1
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• pp.63-67
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• 1996

In order to elucidate the molecular mechanism of plasmid incompatibility of broad host-range plasmid R1162, the plasmid-encoded replication protein RepIB was purified and tested for binding to the 20 bp direct repeat (DR) DNA sequence which is reiterated 3 and 1/2 times within the replicative origin of the plasmid. The RepIB protein specifically binds to the DR DNA. Point mutations in the DR which affect expression of plasmid incompatibility also coordinately affect binding. These results indicate that the incompatibility of broad host-range plasmid R1162 is exerted by the DR DNA by titrating the essential replication protein RepIB.

• BMB Reports
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• v.33 no.2
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• pp.155-161
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• 2000

The saccharomyces cerevisiae Rad27, a structure-specific endonuclease for the okazaski fragment maturation has been known to interact genetically and biochemically with Dna2, an essential enzyme for DNA replication. In an attempt to define the significance of the interaction between the two enzymes, we expressed and purified both Dna2 and Rad27 proteins. In this report, Rad27 could not form a complex with Dna2 in the three different analyses. The analyses included glycerol gradient sedimentation, protein-column chromatography, and coinfection of baculoviruses followed by affinity purification. This is in striking contrast to the previous results that used crude extracts. These results suggest that the interaction between the two proteins is not sufficiently stable or indirect, and thus requires an additional protein(s) in order for Rad27 and Dna2 to form a stable physical complex. This result is consistent with our genetic findings that Schizosaccharomyces pombe Dna2 is capable of interacting with several proteins that include two subunits of polymerase $\delta$, DNA ligase I, as well as Fen-1. In addition, we found that the N-terminal modification of Rad27 abolished its enzymatic activity. Thus, as suspected, we found that on the basis of the structure determination, N-terminal methionine indeed plays an important role in the nucleolytic cleavage reaction.

• YAKHAK HOEJI
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• v.32 no.4
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• pp.239-244
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• 1988

Transcriptional rate of lactate dehydrogenase A-gene(LDH-A) during the prereplicative phase of regenerating rat liver was determined by in vitro run-off transcription assay. The results show that the transcription rate of LDH A-gene increases between 12 hours and 15 hours peaking at 13 hours after partial hepatectomy of rat liver. The increased rate of LDH A-gene transcription was interfered after DL-propranolol treatment intraperitoneally injected twice at 1 hour and 8 hours after partial hepatectomy indicating that the transcriptional control of LDH A-gene expression may be mediated by beta adrenergic receptor and cAMP as a second messenger. And also was it shown that the temporally increased rate of LDH A-gene transcription was maximum one hour after the second cAMP-surge which is known to play an important role for the initiation of DNA replication during regeneration of rat liver. And the transcriptional rate of LDH A-gene was decreased to the basal level at the time period when the hepatocytes proliferate rapidly suggesting that the induced LDH Aisozyme may be required for the initiation of DNA replication during regeneration of rat liver. These data may be supporting for the hypothesis suggesting that the induced LDH A-isozyme during the pre-replicative phase of regenerating rat liver may play bifunctional roles as a glycolytic enzyme and a helix destablizing protein as well.

• YAKHAK HOEJI
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• v.55 no.1
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• pp.75-79
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• 2011

The replication competent adenoviral vector (AV), AdLPCDIRESE1A was generated and reported previously to have cytotoxic effects in some cell lines. In AdLPCDIRESE1A, the expression of cytosine deaminse (CD) and E1A genes are under the control of tumor-specific L-plastin promoter. CD enzyme can deaminate the nontoxic prodrug 5-fluorocytosine (5-FC) to the toxic 5-fluorouracil (5-FU). E1A gene is essential for viral replication. Primary liver cancer, most of which is hepatocellular carcinoma (HCC), is the third common leading cancer in Korea. Thus, we have conducted in vitro preclinical study to evaluate effectiveness of AdLPCDIRESE1A on HCC. The efficacy of cytotoxicity was measured by generation of cytopathic effect (CPE) and cell counting. We infected HepG2 cells with various MOI of vector alone or concurrent with 5-FC. Exposure of cells to AdLPCDIRESE1A generated a significant cytotoxic effect as compared to the control. Almost 83% of the cell had manifested the characteristic cytotoxic effect on day 9 after infection of cells with 10 MOI of vector. We also observed the additive cytotoxic effects when AdLPCDIRESE1A vector had been coadministrated with 5-FC. The results suggest that the use of AdLPCDIRESE1A/5FC may be value in treatment of liver cancer. Further animal studies are needed for clinical trial.

• The Plant Pathology Journal
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• v.27 no.1
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• pp.53-58
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• 2011

Systemic acquired resistance is a form of inducible resistance that is triggered in systemic healthy tissues of local-infected plants. Several candidate signaling molecules emerged in the past two years, including the methylated derivatives of well-known defense hormones salicylic acid (SA) and jasmonic acid (JA). In our present study, the symptom on Cucumber mosaic virus (CMV) infected Arabidopsis leaves in 0.1 mM SA or 0.06 mM JA pre-treated plants was lighter (less reactive oxygen species accumulation and less oxidative damages) than that of the control group. JA followed by SA (JA${\rightarrow}$SA) had the highest inhibitory efficiency to CMV replication, higher than JA and SA simultaneous co-pretreatment (JA+SA), and higher than a JA or a SA single pretreatment. The crosstalk between the two hormones was further investigated at the transcriptional levels of pathogenesis-related genes. The time-course measurement showed JA might play a more important role in the interaction between JA and SA.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.640-642
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• 1998

When resampling an image to a new set of coordinates, there is often a noticeable loss in image quality. The interpolation kernel determines the quality of interpolation. In this paper, We think two interpolation methods: cubic-spline method, neural net method, at first study given interpolation method using spline and then present new interpolation methon using SOFM and LAM(neural net method), finally compare the performance of several interpolation methods including replication, bilinear, spline and new methods.

• Journal of Sericultural and Entomological Science
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• v.25 no.2
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• pp.37-43
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• 1984

The prevalence of the infectious flacherie virus (FV) disease causes a severe damage to cocoon yield and various methods to control the disease have been studied. In this regard, guanidine hydrochloride (GH), one of the guanidine derivatives known as the most inhibitory agent against the replication of picorna virus, was applied to silkworms per os with mulberry leaves and the results were as follows. 1. The application of GH below 0.01% of the chemical concentration did not give any damage to silkworm larvae. 2. The transmission of the virus disease by introducing the FV infected larvae to the healthy larvae group was proportioned to the number of infected larvae. When l% of infected larvae was introduced to the rearing tray of healthy larvae, the pupation rate was 70.7%(79) and it was 38.4% (43) to 5% of infected larvae introduced, while the control of non-mixed with infected larvae gave 89.2% (100) of pupation rate. The cocoon yield from 10,000 larvae also showed the same tendency as the pupation rate. 3. The inhibitory effect of GH against the replication of FV showed ten times in treatment of 0,01% of the chemical agent compared to the non-treatment. 4. The successive application of GH after virus inoculation to silkworm larvae led to the most effective on the inhibition of the virus replication. 5. The immediate application of GH after the virus inoculation also gave the best effect on the inhibition of the virus replication in silkworm larvae. 6. The effect of GH on the inactivation of FV in vitro was not observed.