• Title/Summary/Keyword: OmpA

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Local call processing delay of the control network in ATM switching system (ATM 교환시스템 제어계의 자국호 처리 지연 성능평가)

  • 여환근;송광석;노승환;기장근
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.12
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    • pp.3144-3153
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    • 1996
  • ATM switching system is made up of transport network and control newrk according to its functions. The control device, basic part of control network must be developed before developing any other functions, and control device must be stable and need high reliability. Out distributed ATM switching system consists of several ALSs that provides variable local call services, and an ACS that interconnect among several ALSs. Eech ALS has CCCP that takes charage of call and connection control functions, and ACS has an OMP that takes charge of OA&M(Operation, Administration and Maintenance) functios. In this paper, we analyzed the performance evaluation of control device that manipulate subscriber's call based on ITU-T Q.2931 standard protocol messages and Interprocessor communication messages. As a result of simulation when the number of ALS is under 22, as the call arrival rate increase the processor utilization of CCCP increase rapidly than that of OMP. When the number of ALS is incremented to 22, the processor utilization of CCCP is balanced with the of OMP, and when the number of ALS exceeds 22, the processor utiliztion of OMP increase rapidly. Also if messary processing time of OMP is 1.35 times that of CCCP, processor utilizations of CCCP and OMP is equal.

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Constitutive Expression of Lipase on the Cell Surface of Escherichia coli using OmpC Anchoring Motif

  • Lee, Seung Hwan;Lee, Sang Yup
    • Korean Chemical Engineering Research
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    • v.58 no.2
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    • pp.280-285
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    • 2020
  • We have developed a constitutive display system of the Pseudomonas fluorescens SIK W1 TliA lipase on the cell surface of Escherichia coli using E. coli outer membrane protein C (OmpC) as an anchoring motif, which is an economical compared to induced system. For the constitutive expression of truncated OmpC-TliA fusion proteins, gntT104 promoter was employed. Cell growth was not affected by over expression of fusion protein during entire culture time, suggesting cell lysis was not a problem. The localization of truncated OmpC-TliA fusion protein on the cell surface was confirmed by immunofluorescence microscopy and measuring whole cell lipase activity. Constitutively displayed lipase was very stable, retaining activity enantioselectivity throughout the five repeated reactions. These results suggest that OmpC from E. coli be a useful anchoring motif for displaying enzymes on the cell surface without any inducers, and this stable surface display system can be employed for a broad range of biotechnological applications.

Comparison of the Organophosphorus Hydrolase Surface Display Using InaVN and Lpp-OmpA Systems in Escherichia coli

  • Karami, Ali;Latifi, Ali Mohamad;Khodi, Samaneh
    • Journal of Microbiology and Biotechnology
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    • v.24 no.3
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    • pp.379-385
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    • 2014
  • The purpose of this study was to compare the ability of an engineered Escherichia coli to degrade chlorpyrifos (Cp) using an organophosphorus hydrolase enzyme, encoded in both Flavobacterium sp. ATCC 27551 or Pseudomonas diminuta, by employing the Lpp-OmpA chimera and the N-terminal domain of the ice nucleation protein as anchoring motifs. Tracing of the expression location of the recombinant protein using SDS-PAGE showed the presentation of OPH by both anchors on the outer membrane. This is the first report on the presentation of OPH on the cell surface by Lpp-OmpA under the control of the T7 promoter. The results showed cell growth in the presence of Cp as the sole source of energy, without growth inhibition, and with higher whole-cell activity for both cells harboring plasmids pENVO and pELMO, at approximately 10,342.85 and 10,857.14 U/mg, respectively. Noticeably, the protein displayed by pELMO was lower than the protein displayed by pENVO. It can be concluded that Lpp-OmpA can display less protein, but more functional OPH protein. These results highlight the high potential, of both engineered bacteria, for use in the bioremediation of pesticide-contaminated sources in the environment.

Probabilistic Exclusion Based Orthogonal Matching Pursuit Algorithm for Sparse Signal Reconstruction (희소 신호의 복원을 위한 확률적 배제 기반의 직교 정합 추구 알고리듬)

  • Kim, Seehyun
    • Journal of IKEEE
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    • v.17 no.3
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    • pp.339-345
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    • 2013
  • In this paper, the probabilistic exclusion based orthogonal matching pursuit (PEOMP) algorithm for the sparse signal reconstruction is proposed. Some of recent greedy algorithms such as CoSaMP, gOMP, BAOMP improved the reconstruction performance by deleting unsuitable atoms at each iteration. They still often fail to converge to the solution because the support set could not escape from a local minimum. PEOMP helps to escape by excluding a random atom in the support set according to a well-chosen probability function. Experimental results show that PEOMP outperforms several OMP based algorithms and the $l_1$ optimization method in terms of exact reconstruction probability.

Distribution of Rickettsia spp. in Ticks from Northwestern and Southwestern Provinces, Republic of Korea

  • Jiang, Ju;Choi, Yeon-Joo;Kim, Jeoungyeon;Kim, Heung-Chul;Klein, Terry A;Chong, Sung-Tae;Richards, Allen L.;Park, Hye-Jin;Shin, Sun-Hye;Song, Dayoung;Park, Kyung-Hee;Jang, Won-Jong
    • Parasites, Hosts and Diseases
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    • v.57 no.2
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    • pp.161-166
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    • 2019
  • This study was done to characterize distribution of Rickettsia spp. in ticks in the northwestern and southwestern provinces in the Republic of Korea. A total of 2,814 ticks were collected between May and September 2009. After pooling, 284 tick DNA samples were screened for a gene of Rickettsia-specific 17-kDa protein using nested PCR (nPCR), and produced 88 nPCR positive samples. Of these positives, 75% contained 190-kDa outer membrane protein gene (ompA), 50% 120-kDa outer membrane protein gene (ompB), and 64.7% gene D (sca4). The nPCR products of ompA, ompB, and sca4 genes revealed close relatedness to Rickettsia japonica, R. heilongjiangensis, and R. monacensis. Most Rickettsia species were detected in Haemaphysalis longicornis. This tick was found a dominant vector of rickettsiae in the study regions in the Republic of Korea.

Sparse Signal Recovery with Parallel Orthogonal Matching Pursuit and Its Performances (병렬OMP 기법을 통한 성긴신호 복원과 그 성능)

  • Park, Jeonghong;Jung, Bang Chul;Kim, Jong Min;Ban, Tae Won
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.8
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    • pp.1784-1789
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    • 2013
  • In this paper, parallel orthogonal matching pursuit (POMP) is proposed to supplement the orthogonal matching pursuit (OMP) which has been widely used as a greedy algorithm for sparse signal recovery. The process of POMP is simple but effective: (1) multiple indexes maximally correlated with the observation vector are chosen at the firest iteration, (2) the conventional OMP process is carried out in parallel for each selected index, (3) the index set which yields the minimum residual is selected for reconstructing the original sparse signal. Empirical simulations show that POMP outperforms than the existing sparse signal recovery algorithms in terms of exact recovery ratio (ERR) for sparse pattern and mean-squared error (MSE) between the estimated signal and the original signal.

Display of Proteins on the Surface of Escherichia coli by C-Terminal Deletion Fusion to the Salmonella typhimurium OmpC

  • CHOI JONG-HYUN;CHOI, JONG-IL;LEE, SANG-YUP
    • Journal of Microbiology and Biotechnology
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    • v.15 no.1
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    • pp.141-146
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    • 2005
  • A new system for displaying proteins on the surface of Escherichia coli was developed using the Salmonella typhimurium outer membrane protein C (OmpC) as an anchoring motif. The C-terminal deletionfusion strategy was developed to fuse the polyhistidine peptides and green fluorescent protein (GFP) to the Cterminal of the truncated functional portion of OmpC. The polyhistidine peptides of up to 243 amino acids could besuccessfully displayed on the E. coli cell surface, which allowed recombinant E. coli to adsorb up to 34.2 μmol of Cd2+ per gram dry cell weight. The GFP could also be successfully displayed on the E. coli cell surface. These results suggest that the C-terminal deletion-fusion strategy employing the S. typhimurium OmpC as an anchoring motif provides a new efficient way for the display of large proteins on the surface of E. coli.

ePRO-OMP: A Tool for Performance/Energy PRofiler and Analyzer for OpenMP Applications (ePRO-OMP: OpenMP 응용 프로그램의 성능 및 에너지 분석 도구)

  • Lee, Young-Ho;Kim, Jihong
    • IEMEK Journal of Embedded Systems and Applications
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    • v.6 no.5
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    • pp.287-293
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    • 2011
  • As chip multiprocessors have been widely adopted in embedded systems, achieving both high performance and low power consumptions of parallel applications becomes challenging. In order to meet these requirements, it is crucial for developers to analyze the performance and energy consumption of parallel applications. In this paper, we propose a tool for profiling and optimizing the performance and energy consumption of OpenMP applications (energy PROfiler and analyzer for OpenMP: ePRO-OMP). The main advantage of ePRO-OMP is that it can analyze both the performance and energy consumption of each parallel region of an OpenMP application, which can help developers find the bottleneck of parallel applications in detail.

Brucella melitensis omp31 Mutant Is Attenuated and Confers Protection Against Virulent Brucella melitensis Challenge in BALB/c Mice

  • Verdiguel-Fernandez, L;Oropeza-Navarro, R;Ortiz, Adolfo;Robles-Pesina, MG;Ramirez-Lezama, J;Castaneda-Ramirez, A;Verdugo-Rodriguez, A
    • Journal of Microbiology and Biotechnology
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    • v.30 no.4
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    • pp.497-504
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    • 2020
  • For control of brucellosis in small ruminants, attenuated B. melitensis Rev1 is used but it can be virulent for animals and human. Based on these aspects, it is essential to identify potential immunogens to avoid these problems in prevention of brucellosis. The majority of OMPs in the Omp25/31 family have been studied because these proteins are relevant in maintaining the integrity of the outer membrane but their implication in the virulence of the different species of this genus is not clearly described. Therefore, in this work we studied the role of Omp31 on virulence by determining the residual virulence and detecting lesions in spleen and testis of mice inoculated with the B. melitensis LVM31 mutant strain. In addition, we evaluated the conferred protection in mice immunized with the mutant strain against the challenge with the B. melitensis Bm133 virulent strain. Our results showed that the mutation of omp31 caused a decrease in splenic colonization without generating apparent lesions or histopathological changes apparent in both organs in comparison with the control strains and that the mutant strain conferred similar protection as the B. melitensis Rev1 vaccine strain against the challenge with B. melitensis Bm133 virulent strain. These results allow us to conclude that Omp31 plays an important role on the virulence of B. melitensis in the murine model, and due to the attenuation shown by the strain, it could be considered a vaccine candidate for the prevention of goat brucellosis.

Effect of Omeprazole on Membrane P-Type ATPase and Peptide Transport in Helicobacter pylori

  • KI, MI-RAN;SOON-KYU YUN;SE-YOUNG HWANG
    • Journal of Microbiology and Biotechnology
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    • v.9 no.3
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    • pp.235-242
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    • 1999
  • We investigated the growth-inhibitory mechanism of Helicobacter pylori by omeprazole (OMP) and its activated sulfenamide (OAS). Using dithiothreitol (DTT) and 5,5'-dithio-bis[2-nitrobenzoic acid] (DTNB; Ellman's reagent), we first determined the relationship between the binding capacity of these compounds to H. pylori membrane and its significance to membrane P-type ATPase activity. After incubation of the intact H. pylori cells with either OMP or OAS, the residual quantity of free SH-groups on the cell membrane was measured, and, the resulting values were plotted as a function of time. From this experiment, we found that there was a considerable difference in the membrane-binding rates between OMP and OAS. At neutral pH, the disulfide bond formation on H. pylori membrane was completed within 2 min of incubation of the intact cells with OAS. By OMP, however, it was gradually formed, exceeding 10 min of incubation for completion, whereby, the extent of P-type ATPase inhibition appeared to be proportional to the disulfide forming rate. From this data, it was suggested that the disulfide formation might directly affect enzyme activity. Since OMP per se cannot yield a disulfide bond with cysteine, it is predicted that the enzyme inactivation must be caused by the OAS form. Accordingly, we postulated that, under the neutral pH, OMP could be converted to OAS in the course of transport. By extrapolating the inhibitory slopes, we could evaluate K₁ values, relating to their minimal inhibitory concentrations (MICs) for H. pylori growth. In these MIC ranges, H. pylori uptake or vesicular export of nutrients such as peptides were totally prohibited, but their effect in Escherichia coli were negligible. From these observations, we strongly suggest that the P-type ATPase activity is essential for the survival of H. pylori cells in particular.

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