• Title/Summary/Keyword: LMV

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Characteristics of a Lettuce mosaic virus Isolate Infecting Lettuce in Korea

  • Lim, Seungmo;Zhao, Fumei;Yoo, Ran Hee;Igori, Davaajargal;Lee, Su-Heon;Lim, Hyoun-Sub;Moon, Jae Sun
    • The Plant Pathology Journal
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    • v.30 no.2
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    • pp.183-187
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    • 2014
  • Lettuce mosaic virus (LMV) causes disease of plants in the family Asteraceae, especially lettuce crops. LMV isolates have previously been clustered in three main groups, LMV-Yar, LMV-Greek and LMV-RoW. The first two groups, LMV-Yar and LMV-Greek, have similar characteristics such as no seed-borne transmission and non-resistance-breaking. The latter one, LMV-RoW, comprising a large percentage of the LMV isolates contains two large subgroups, LMV-Common and LMV-Most. To date, however, no Korean LMV isolate has been classified and characterized. In this study, LMV-Muju, the Korean LMV isolate, was isolated from lettuce showing pale green and mottle symptoms, and its complete genome sequence was determined. Classification method of LMV isolates based on nucleotide sequence divergence of the NIb-CP junction showed that LMV-Muju was categorized as LMV-Common. LMV-Muju was more similar to LMV-O (LMV-Common subgroup) than to LMV-E (LMV-RoW group but not LMV-Common subgroup) even in the amino acid domains of HC-Pro associated with pathogenicity, and in the CI and VPg regions related to ability to overcome resistance. Taken together, LMV-Muju belongs to the LMV-Common subgroup, and is expected to be a seed-borne, non-resistance-breaking isolate. According to our analysis, all other LMV isolates not previously assigned to a subgroup were also included in the LMV-RoW group.

Spatial Characteristics of Low Meteorological Visibility over Hongkong and Statistical Retrieval from Satellite Data

  • Fei, HUANG;Jun-Ping, QIAN;Zu-Qiang, CUI;Zhi-Hong, ZHENG;Zhi-Jun, WU
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.1261-1263
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    • 2003
  • Based on twelve observational stations low meteorological visibility (LMV) data during November 2002 to April 2003, the spatial distribution of LMV over Hongkong area (113.8$^{\circ}$ E-114.4$^{\circ}$ E, 22.1$^{\circ}$ N-22.4$^{\circ}$ N) is studied, using a PCA method. Optical spectrum of NOAA-16 associated with LMV shows that the significant effect factors correlated with LMV in the leading mode are the difference or rate between the visible and near-IR channels and single visible channel. A successful retrieval of LMV is done and a regression equation with a multiple correlation coefficient of 0.67 is obtained.

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One-step Multiplex RT-PCR Method for Simultaneous Detection of Seed Transmissible Bacterium and Virus Occurring on Brassicaceae Crop Seeds (십자화과 작물 종자에서 종자전염 세균 및 바이러스 동시 검출을 위한 One-step Multiplex RT-PCR 방법)

  • Jeong, Kyu-Sik;Soh, Eun-Hee
    • Research in Plant Disease
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    • v.17 no.1
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    • pp.52-58
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    • 2011
  • The aim of this research was to develop specific and sensitive PCR-based procedures for simultaneous detection of economically important plant pathogenic bacteria and seed borne virus in commercial Brassicaceae crop seeds, Xanthomonns campestris pv. campestris (Xcc) and Lettuce Mosaic Virus (LMV). Bacterial and virus diseases of Brassicaceae leaves are responsible for heavy losses. PCR with arbitral primers: selection of specific primers, performance of PCR with specific primers and determination of the threshold level for pathogens detection. To detect simultaneously the Xcc and LMV in commercial Brassicaceae crop seeds (lettuce, kohlrabi, radish, chinese cabbage and cabbage), two pairs of specific primer (LMV-F/R, Xcc-F/R) were synthesized by using primer-blast program (http://www.ncbi.nlm.nih.gov/tools/primer-blast/). The multiplex PCR for the two pathogens in Brassicaceae crop seeds could detect specifically without interference among primers and/or cDNA of other plant pathogens. The pathogen detection limit was determined at 1 ng of RNA extracted from pathogens. In the total PCR results for pathogen detection using commercial kohlrabi (10 varieties), lettuce (50 varieties), radish (20 varieties), chinese cabbage (20 varieties) and cabbage (20 varieties), LMV and Xcc were detected from 39 and 2 varieties, respectively. In the PCR result of lettuce, LMV and Xcc were simultaneously detected in 8 varieties.

Effects of Ukgansan (Yokukansan in Japanese, Yigansan in chinese) on the Locomotor Velocity and Glutamate-Induce Paroxysm in Planarian (Planarian 모델을 이용한 억간산의 항발작 효과)

  • Park, Woong;Yoo, Du Man;So, June No
    • KSBB Journal
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    • v.29 no.1
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    • pp.67-71
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    • 2014
  • Planaria were recently reported to be a simple and sensitive model to investigate the mechanistic aspect of seizure and to screen potential anticonvulsants. Using planarian model, we analyzed the pharmacological effect of ukgansan (UGS), an oriental herbal medicine containing seven medicinal herbs, on the planarian locomotor velocity (pLMV) and glutamate-induced seizure-like activity (pSLA). To test whether D. japonica is suitable for studying anti-seizure agents, we investigated the effect of glutamate on pLMV and pSLA in D. japonica. In the present study we first confirmed that pSLA in D. japonica was induced by L-glutamate. Glutamate significantly produced pSLA in a dose dependent manner, but did not affect pLMV. These glutamate-induced paroxysms were decreased by antiepileptic drug, topiramate. A similar inhibitory effect on glutamate-induced pSLA was observed after the treatment of UGS. The present results suggest that UGS and its active constituents possess useful substance inhibiting seizure in planarian and that D. japonica provides a convenient model to search active herbs containing anti-seizure activity.

Dynamic Responses Optimization of Vacuum Circuit Breaker Using Taghchi Method (실험 계획법을 이용한 진공 차단기의 동특성 최적화)

  • Jo, Jun Yeon;Ahn, Kil Young;Kim, Sung Tae;Yang, Hong Ik;Kim, Kyu Jung
    • Transactions of the KSME C: Technology and Education
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    • v.3 no.2
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    • pp.141-148
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    • 2015
  • In this study, the VCB(Vacuum Circuit Breaker) has been developed using the Recurdyn that is widely used on multibody dynamics analysis. The VCB consists of three main circuits with the VI(Vacuum Interrupter) and the main frame with the operating mechanism. This analytic model is validated by comparing the simulation results and the experimental results. Generally, in order to reliably cut off the breaking current, the opening speed of the VCB after contact separation has to be a 0.9~1.1m/s. Therefore, the study of the design parameters of the VCB is needed. To improve the opening velocity, Taguchi design method is applied to optimize the design parameters of a VCB with a lot of linkages. In addition, to evaluate the improvement of the operating characteristics, the simulation results are compared with the Recurdyn and experimental results with improved prototype sample.

Quadrature VCO as a Subharmonic Mixer

  • Oh, Nam-Jin
    • International journal of advanced smart convergence
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    • v.10 no.3
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    • pp.81-88
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    • 2021
  • This paper proposes two types of subharmonic RF receiver front-end (called LMV) where, in a single stage, quadrature voltage-controlled oscillator (QVCO) is stacked on top of a low noise amplifier. Since the QVCO itself plays the role of the single-balanced subharmonic mixer with the dc current reuse technique by stacking, the proposed topology can remove the RF mixer component in the RF front-end and thus reduce the chip size and the power consumption. Another advantage of the proposed topologies is that many challenges of the direct conversion receiver can be easily evaded with the subharmonic mixing in the QVCO itself. The intermediate frequency signal can be directly extracted at the center taps of the two inductors of the QVCO. Using a 65 nm complementary metal oxide semiconductor (CMOS) technology, the proposed subharmonic RF front-ends are designed. Oscillating at around 2.4 GHz band, the proposed subharmonic LMVs are compared in terms of phase noise, voltage conversion gain and double sideband noise figure. The subharmonic LMVs consume about 330 ㎼ dc power from a 1-V supply.

A Decomposition Algorithm for a Local Access Telecommunication Network Design Problem

  • Cho, Geon
    • Journal of the Korean Operations Research and Management Science Society
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    • v.23 no.2
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    • pp.29-46
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    • 1998
  • In this paper, we develop detailed algorithms for implementing the so-called Limited Column Generation procedure for Local Access Telecommunication Network(LATN) design problem. We formulate the problem into a tree-partitioning problem with an exponential number of variables. Its linear programming relaxation has all integral vertices, and can be solved by the Limited Column Generation procedure in just n pivots, where n is the number of nodes in the network. Prior to each pivot. an entering variable is selected by detecting the Locally Most Violated(LMV) reduced cost, which can be obtained by solving a subproblem in pseudo-polynomial time. A critical step in the Limited Column Generation is to find all the LMV reduced costs. As dual variables are updated at each pivot, the reduced costs have to be computed in an on-line fashion. An efficient implementation is developed to execute such a task so that the LATN design problem can be solved in O(n$^2$H), where H is the maximum concentrator capacity. Our computational experiments indicate that our algorithm delivers an outstanding performance. For instance, the LATN design problem with n=150 and H=1000 can be solved in approximately 67 seconds on a SUN SPARC 1000 workstation.

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A decomposition algorithm for local access telecommunication network design problem

  • Cho, Geon
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1995.04a
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    • pp.54-68
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    • 1995
  • In this paper, we develop detailed algorithms for implementing the so-called Limited Column Generation procedure for Local Access Telecommunication Network (LATN) Design problem. We formulate the problem into a tree-partitioning problem with an exponential number of variables. Its linear programming relaxation has all integral vertices, and can be solved by the Limited Column. Generation procedure in just n pivots, where n is the number of nodes in the network. Prior to each pivot, an entering variable is selected by detecting the Locally Most Violated (LMV) reduced cost, which can be obtained by solving a subproblem in pseudo-polynomial time. A critical step in the Limited Column Generation is to find all the LMV reduced costs. As dual variables are updated at each pivot, the reduced costs have to be computed in an on-line fashion. An efficient implementation is developed to execute such a task so that the LATN Design problem can be solved in O(n$^{2}$H), where H is the maximum concentrator capacity. Our computational experiments indicate that our algorithm delivers an outstanding performance. For instance, the LATN Design problem with n = 150 and H = 1000 can be solved in approximately 67 seconds on a SUN SPARC 1000 workstation.

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Single-balanced Direct Conversion Quadrature Receiver with Self-oscillating LMV

  • Nam-Jin Oh
    • International Journal of Internet, Broadcasting and Communication
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    • v.15 no.3
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    • pp.122-128
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    • 2023
  • This paper proposes two kinds of single-balanced direct conversion quadrature receivers using selfoscillating LMVs in which the voltage-controlled oscillator (VCO) itself operates as a mixer while generating an oscillation. The two LMVs are complementary coupled and series coupled to generate the quadrature oscillating signals, respectively. Using a 65 nm CMOS technology, the proposed quadrature receivers are designed and simulated. Oscillating at around 2.4 GHz frequency, the complementary coupled quadrature receiver achieves the phase noise of -28 dBc/Hz at 1KHz offset and -109 dBc/Hz at 1 MHz offset frequency. The other series coupled receiver achieves the phase noise of -31 dBc/Hz at 1KHz offset and -109 dBc/Hz at 1 MHz offset frequency. The simulated voltage conversion gain of the two single-balanced receivers is 37 dB and 45 dB, respectively. The double-sideband noise figure of the two receivers is 5.3 dB at 1 MHz offset. The quadrature receivers consume about 440 μW dc power from a 1.0-V supply.

Long Term Effects of Lamivudine and Adefovir dipivoxil in Chronic Hepatitis B Patients on the Development of Hepatocellular Carcinoma (만성 B형간질환에서 HBV백신 및 항바이러스치료가 간세포암종 발생에 미치는 효과)

  • Lee, Heon-Ju
    • Journal of Yeungnam Medical Science
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    • v.25 no.1
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    • pp.1-18
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    • 2008
  • Although Lamivudine and adefovir dipivoxil are efficacious drugs for preventing hepatocellular carcinoma (HCC) in chronic hepatitis B patients, their efficacy is far from completely satisfactory. The risk of liver cirrhosis and HCC begins to increase at an HBV DNA level of $10^4$ copies/ml. Even with latent or past HBV infection, episomal covalently closed circular DNA(cccDNA) plays a key rolein the persistence, relapse and resistance of HBV in its natural course or during therapy. The annual incidence of HCC in YUMC is 1.8% and 4.7% patients/year in the antiviral treatment and control groups, respectively. The ability to achieve a high rate of sustained HBV suppression with low risk of drug resistance is the ultimate goal in the treatment of chronic HBV infection. The efficacy of universal immunization with striking reductions in the prevalence of HBV in localized countries needs to be spread worldwide. With hepatitis B immunization and effective antiviral therapy, global control of HBV infection and HBV-related complications, including HCC, are possible by the end of the first half of the $21^{st}$ century.

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