• Korean Journal Plant Pathology
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• v.14 no.2
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• pp.136-144
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• 1998

Many cloves of native cultivated garlics in Korea were found to be infested by mites when observed with stereo-microscope. The mite was identified by light and scanning electron microscopic observation as Aceria tulipae. Surveying viruses from the vegetatively propagated garlic, highly flexuous, filamentous particles (700∼800 nm) were detected in Aceria tulipae, local lesions of Chenopodium murale after sap transmissions, mosaic garlic leaves inoculated with mite-borne virus by transmission of Aceria tulipae and naturally infected garlic leaves. The mite-borne virus isolated did not react with antisera of aphid-borne potyviruses (LYSV-G, LYSV-L, WoYSV) or carlavirus (GLV), but reacted with antisera of garlic mite-borne viruses (GV-C, GMbMV). In ultratin sections of mite-borne virus infected garlic tissues, aggregates of virus particles and membrane proliferations were found in the parenchyma cells, but cytoplasmic cylindrical inclusions were not observed. Heavily mite-infested plants showed streaking and malformation due to mite feeding. The mite-borne virus was identified as garlic mite-borne mosaic virus (GMbMV), the mite-borne genus Rymovirus of the Potyviridae by mite transmission, morphology of virus particles, serological relationships, host range, distribution pattern of virus particles and inclusion bodies in the infected cells. The results demonstrate that mite-borne virus is one of the major viruses infecting native cultivated garlic plants showing mosaic or streak symptoms in Korea.

• Korean Journal Plant Pathology
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• v.13 no.2
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• pp.73-78
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• 1997

A virus was purified from Korean cactus (Chamaeaereus silverstrii f. Variegata Hort) showing necrotic spots and its biophysicochemical properties were examined. The typical necrotic spots were observed on healthy looking cactus inoculated with the purified virus and the various symptoms from necrotic spots to systemic were observed on 17 species of test plats used, which suggests that the purified virus has the normal infectivity and wide host range. Ultraviolet absorption scanning analysis revealed that the viral preparation had the typical curve with shoulder at 290 nm and its ratio of absorbances at 260 nm to 280 nm and extinction coefficient was 1.156 and 2.86, respectively. The virus represented one distinct and homogeneous band and molecular weight of viral coat protein was determined to 17, 000 Dalton by SDS-PAGE. The virus revealed rod-shaped virion (325$\times$20 nm) by electron microscopy. Based on these results, it has been thought that the virus purified in this study is the pathogenic agents causing necrotic spot symptom on Korean cacuts and one of the member of tobamovirus family.

• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.2
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• pp.177-181
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• 2000

Spilarctia obliqua(Wlk.) is a serious pest of mulberry which is naturally affected by its nucleopolyhedrosis virus (SoNPV) in field conditions. The polyhedral occlusion bodies (POB's) were hexahedron under scanning and transmission electron microscope and measured 0.42${\mu}{\textrm}{m}$ to 0.67 ${\mu}{\textrm}{m}$ in diameter. The symptoms of NPV infected S. obliqua larvae resembled with that of other NPVs' infected lepidopterous larvae. The pathogenicity and potentiality of this virus against S. obliqua was tested in the laboratory conditions and the results showed 100% mortality in larvae inoculated with SoNPV at 6.23${\times}10^5$ POBs/ml. Therefore, SoNPV appears to have a high potential as a microbial biocontrol agent against S. obliqua larvae.

• Research in Plant Disease
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• v.10 no.1
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• pp.44-47
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• 2004

Soil transmission ratio of Cucumber green mottle mosaic virus (CGMMV) was 0.2 to 3.5 ％ in watermelon growing fields naturally infested with the virus. Biological activities of CGMMV lost after 17 months in moist well-aerated soil but still continued more than 33 months in waterlogged soil. To inhibit the virus infection through soil, the roots of watermelon seedlings were soaked in 10％ solution of skim milk prior to transplanting. The seedlings treated with skim milk solution were not infected, while 5.0 to 7.6％ out of control seedlings were infected. The roots treated with skim milk were coated with membrane around the roots under scanning electron microscope.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.11
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• pp.861-869
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• 2013

We consider an information system where viruses arrive according to a Poisson process with rate ${\lambda}$. The information system has two types of anti-virus operation policies including 'real-time scan' and 'batch scan.' In the real-time scan policy, a virus is assumed to be scanned immediately after its arrival. Consequently, the real-time scan policy assumes infinite number of anti-viruses. We assume that the time for scanning and curing a virus follows a general distribution. In the batch scan policy, a system manager operates an anti-virus every deterministic time interval and scan and cure all the viruses remaining in the system simultaneously. In this paper we suggest a probability model for the operation of anti-virus software. We derive a condition under which the operating policy is achieved. Some numerical examples with various cost structure are given to illustrate the results.

• International Journal of Computer Science & Network Security
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• v.23 no.7
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• pp.202-209
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• 2023

Android malware is now on the rise, because of the rising interest in the Android operating system. Machine learning models may be used to classify unknown Android malware utilizing characteristics gathered from the dynamic and static analysis of an Android applications. Anti-virus software simply searches for the signs of the virus instance in a specific programme to detect it while scanning. Anti-virus software that competes with it keeps these in large databases and examines each file for all existing virus and malware signatures. The proposed model aims to provide a machine learning method that depend on the malware detection method for Android inability to detect malware apps and improve phone users' security and privacy. This system tracks numerous permission-based characteristics and events collected from Android apps and analyses them using a classifier model to determine whether the program is good ware or malware. This method used the machine learning techniques KNN-SVM, DBN, and GRU in which help to find the accuracy which gives the different values like KNN gives 87.20 percents accuracy, SVM gives 91.40 accuracy, Naive Bayes gives 85.10 and DBN-GRU Gives 97.90. Furthermore, in this paper, we simply employ standard machine learning techniques; but, in future work, we will attempt to improve those machine learning algorithms in order to develop a better detection algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.11
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• pp.5642-5670
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• 2017

Antivirus is an important issue to the security of virtual machine (VM). According to where the antivirus system resides, the existing approaches can be categorized into three classes: internal approach, external approach and hybrid approach. However, for the internal approach, it is susceptible to attacks and may cause antivirus storm and rollback vulnerability problems. On the other hand, for the external approach, the antivirus systems built upon virtual machine introspection (VMI) technology cannot find and prohibit viruses promptly. Although the hybrid approach performs virus scanning out of the virtual machine, it is still vulnerable to attacks since it completely depends on the agent and hooks to deliver events in the guest operating system. To solve the aforementioned problems, based on in-memory signature scanning, we propose an agentless runtime antivirus system VirtAV, which scans each piece of binary codes to execute in guest VMs on the VMM side to detect and prevent viruses. As an external approach, VirtAV does not rely on any hooks or agents in the guest OS, and exposes no attack surface to the outside world, so it guarantees the security of itself to the greatest extent. In addition, it solves the antivirus storm problem and the rollback vulnerability problem in virtualization environment. We implemented a prototype based on Qemu/KVM hypervisor and ClamAV antivirus engine. Experimental results demonstrate that VirtAV is able to detect both user-level and kernel-level virus programs inside Windows and Linux guest, no matter whether they are packed or not. From the performance aspect, the overhead of VirtAV on guest performance is acceptable. Especially, VirtAV has little impact on the performance of common desktop applications, such as video playing, web browsing and Microsoft Office series.

• Journal of Microbiology and Biotechnology
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• v.26 no.1
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• pp.151-159
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• 2016

Nanoparticles have wide-scale applications in various areas, including medicine, chemistry, electronics, and energy generation. Several physical, biological, and chemical methods have been used for synthesis of silver nanoparticles. Green synthesis of silver nanoparticles using plants provide advantages over other methods as it is easy, efficient, and eco-friendly. Nanoparticles have been extensively studied as potential antimicrobials to target pathogenic and multidrug-resistant microorganisms. Their applications recently extended to development of antivirals to inhibit viral infections. In this study, we synthesized silver nanoparticles using Cinnamomum cassia (Cinnamon) and evaluated their activity against highly pathogenic avian influenza virus subtype H7N3. The synthesized nanoparticles were characterized using UVVis absorption spectroscopy, scanning electron microscopy, and Fourier transform infrared spectroscopy. Cinnamon bark extract and its nanoparticles were tested against H7N3 influenza A virus in Vero cells and the viability of cells was determined by tetrazolium dye (MTT) assay. The silver nanoparticles derived from Cinnamon extract enhanced the antiviral activity and were found to be effective in both treatments, when incubated with the virus prior to infection and introduced to cells after infection. In order to establish the safety profile, Cinnamon and its corresponding nanoparticles were tested for their cytotoxic effects in Vero cells. The tested concentrations of extract and nanoparticles (up to 500 μg/ml) were found non-toxic to Vero cells. The biosynthesized nanoparticles may, hence, be a promising approach to provide treatment against influenza virus infections.

• Korean Journal of Veterinary Research
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• v.32 no.1
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• pp.83-90
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• 1992

Monoclonal antibodies against structural proteins of bovine viral diarrhea virus(BVDV) were derived by classical hybridoma techniques. These antibodies were characterized by serum neutralization, immunoblotting and immunoprecipitation. The neutralizing monoclonal antibody reacted with the 56kd to 54kd(M.W.) viral protein in western blotting and immunoprecipitation analysis. Although there was no neutralizing activity, another monoclanal antibody reacted with the 45kd protein by immunoprecipitation and with both the 45kd and 36kd proteins in immunoblotting analysis. respectively. Densitometer scanning of purified BVDV and the immunopreipitation of whole virus particles with neutralizing monoclonal antibody revealed the presence of more than twelve viral polypeptides. Although no possible precursor form of protein was identified with the neutralizing monoclonal antibody. the presence of intact virion was detected in the infected cell supernatant immediatelty after pulse labeling, indicating rapid translational processing as well as packaging of the virus. The partial peptide mapping of 45kd and 36kd proteins with Staphylococcus aureus V 8 protease showed that these two proteins are related.

• BMB Reports
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• v.38 no.3
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• pp.354-359
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• 2005

Open reading frame 29 (ha29) is a gene specific for Helicoverpa armigera single-nucleocapsid nucleopolyhedrovirus (HearSNPV). Sequence analyses showed that the transcription factor Tfb2 motif, bromodomain and Half-A-TPR (HAT) repeat were present at aa 66-82, 4-76, 55-90 of the Ha29 protein respectively. The product of Ha29 was detected in HearSNPV-infected HzAM1 cells at 3 h post-infection. Western blot analysis using a polyclonal antibody produced by immunizing a rabbit with purified GST-Ha29 fusion protein indicates that Ha29 is an early gene. The size of Ha29 product in infected HzAM1 cells was about 25 kDa, which was larger than the presumed size of 20.4 kDa. Tunicamycin treatment of HearSNPV-infected HzAM1 cells suggested that the Ha29 protein is N-glycosylated. Fluorescent confocal laser scanning microscope examination, and Western blot analysis of purified budded virus (BVs), occlusion-derived virus (ODVs), cell nuclear and cytoplasmic fraction, showed that the Ha29 protein was localized in the nucleus. Our results suggested that ha29 of HearSNPV encodes a non-structurally functional protein that may be associated with virus gene transcription in Helicoverpa hosts.