• Title/Summary/Keyword: Selective vector

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Use of .lambda.gt 11 and antibody probes to isolate genes encoding RNA polymerase subunits from bacillus subtilis

  • Suh, Joo-Won;Price, Chester
    • The Microorganisms and Industry
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    • v.14 no.1
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    • pp.17-20
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    • 1988
  • A genetic analysis of the complex Bacillus subtilis transcriptional apparatus is essential to understand the function, regulation, and interaction of the transcriptase components during growth and sporulation. This approach in Escherichia coli has uncovered fundamental mechanisms regulating gene expression Cole and Nomura, 1986; Lindahl and Zengel, 1986) and an analysis of the B. subtilis transcriptase will allow comoparison of the E.coli system to another bacterium that has evolved under different selective pressures. To this end we used antibody probes to isolate the alpha, beta, and beta' core subunit genes from a .lambda.gtill expression vector library. To address the question of function ans regulation of the minor sigma factors that confer promoter specifity on the polymerase core (Losick et al., 1986), we used the same approach to isolate the gene for the 37,000 dalton sigma factor, sigma-37.

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Detection of mass type-Breast Cancer using Homogeneity and Ranklets on Dense Mammographic Images (Homogeneity와 Ranklets를 이용한 치밀 유방에서의 종괴(mass)형 암 검출)

  • Park, Jun-Young;Chon, Min-Su;Kim, Won-Ha;Kim, Sung-Min
    • Proceedings of the KIEE Conference
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    • 2006.10c
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    • pp.148-150
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    • 2006
  • In this paper, we propose a new method for detection of mass-type breast cancer in dense mammogram. As the proposed method analyzes texture of the breast tissue using method by fusing Homogeneity and Ranklets, improve problem of traditional method. Homogeneity gives the measure of uniform density, and Ranklets determine orientation selective property at vertical, horizontal and diagonal in mass region. The proposed method is suitable to dense mammogram with tangled normal tissue and cancer tissue. SVM(Support Vector Machine) classifier is used for effective detection of mass-type breast cancer in dense mammogram.

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Study on Hybrid PWM Method under Low Switching Frequency

  • Kekang, Wei;Zheng, Trillion Q.;Wang, Ran;Wang, Chenchen
    • Journal of international Conference on Electrical Machines and Systems
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    • v.1 no.2
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    • pp.64-69
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    • 2012
  • This paper presents a hybrid pulse width modulation (PWM) method under low switching frequency conditions based on space vector PWM (SVPWM) and selective harmonic eliminated PWM (SHEPWM), which use asynchronous carrier modulation SVPWM at low frequency, and SHEPWM at high frequency, a square wave after rated conditions. A transitive strategy is proposed to realize a smooth transition of individual modes including SVPWM, SHEPWM and square waves. Experimental results confirm this hybrid modulation method and their transition are reasonable and proper.

Application of Step Length Technique To An Eigensolution Method for Non-proportionally Damped Systems (Step Length를 이용한 비비례감쇠시스템의 고유치 해석)

  • Thanh X. H;Kim, Byoung-Wan;Jung, Hyung-Jo;Lee, In-Won
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.03a
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    • pp.481-490
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    • 2003
  • This paper presents an efficient eigensolution method for non-proportionally damped systems. The proposed method is obtained by applying the accelerated Newton-Raphson technique and the orthonormal condition of the eigenvectors to the linearized form of the quadratic eigenproblem. A step length and a selective scheme are introduced to increase the convergence of the solution. The step length can be evaluated by minimizing the norm of the residual vector using the least square method. While the singularity may occur during factorizing process in other iteration methods such as the inverse iteration method and the subspace iteration method if the shift value is close to an exact eigenvalue, the proposed method guarantees the nonsingularity by introducing the orthonormal condition of the eigenvectors, which can be proved analytically. A numerical example is presented to demonstrate the effectiveness of the proposed method.

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Production of Transgenic Melon from the Cultures of Cotyledonary-Node Explant Using Agrobacterium-Mediated Transformation (Agrobacterium 공동 배양을 통한 자엽절 절편 배양으로부터 멜론 형질전환체 생산)

  • Cho Mi-Ae;Song Yun-Mi;Park Yun-Ok;Ko Suck-Min;Min Sung-Ran;Liu Jang-Ryol;Lee Jun-Haeng;Choi Pil-Son
    • Journal of Plant Biotechnology
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    • v.32 no.4
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    • pp.257-262
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    • 2005
  • Agrobacterium tumefaciens-mediated cotyledonary-node explants transformation was used to produce transgenic melon. Cotyledonary-node explants of melon (Cucumis melo L. cv. Super VIP) were co-cultivated with Agrobacterium strains (LBA4404, GV3101, EHA101) containing the binary vector (pPTN289) carrying with CaMV 35S promoter-gus gene as reporter gene and NOS promoter-bar gene conferring resistance to glufosinate (herbicide Basta) as selective agent, and the binary vector (pPTN290) carrying with Ubiquitin promoter-GUS gene and NOS promoter-nptll gene conferring resistance to paromomycin as selective agent, respectively. The maximum transformation efficiency (0.12%) was only obtained from the cotyledonary-node explants co-cultivated with EHA101 strain (pPTN289) on selection medium with 5 mg/L glufosinate and not produced a transgenic melon from the cotyledon or cotyledonary-node co-cultivated with other strains. Finally, five plants transformed showed the resistance in glufosinate antibiotic and the GUS positive response in leaf ($T_0$), flower ($T_0$), seeds ($T_1$) and plantlet ($T_1$). Southern blot analysis revealed that the gus gene integrated into each genome of transgenic melon.

Connectivity of the GAODV Routing Protocol (GAODV 라우팅 프로토콜의 연결성)

  • Choi, Youngchol
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.7
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    • pp.1306-1312
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    • 2017
  • The route request (RREQ) packet is selectively re-broadcasted in the routing protocols that improve the broadcast storm problem of the ad-hoc on-demand routing protocol (AODV). However, in a low node density scenario, the connectivity of these selective rebroadcast schemes becomes less than that of the AODV. In order to clarify the requirements of these selective re-broadcast routing protocols, it is necessary to investigate the relationship between the node density and the connectivity. In this paper, we drive a probability to preserve the connectivity of the GAODV at an intermediate rebroadcast node. In addition, we present an intuitive method to approximate the end-to-end connectivity of the GAODV. We draw the required node density to guarantee the connectivity of 0.9 and 0.99 through computer simulations, and verify the validity of the derived theoritical connectivity by comparing with the simulation results.

Feature Extraction to Detect Hoax Articles (낚시성 인터넷 신문기사 검출을 위한 특징 추출)

  • Heo, Seong-Wan;Sohn, Kyung-Ah
    • Journal of KIISE
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    • v.43 no.11
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    • pp.1210-1215
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    • 2016
  • Readership of online newspapers has grown with the proliferation of smart devices. However, fierce competition between Internet newspaper companies has resulted in a large increase in the number of hoax articles. Hoax articles are those where the title does not convey the content of the main story, and this gives readers the wrong information about the contents. We note that the hoax articles have certain characteristics, such as unnecessary celebrity quotations, mismatch in the title and content, or incomplete sentences. Based on these, we extract and validate features to identify hoax articles. We build a large-scale training dataset by analyzing text keywords in replies to articles and thus extracted five effective features. We evaluate the performance of the support vector machine classifier on the extracted features, and a 92% accuracy is observed in our validation set. In addition, we also present a selective bigram model to measure the consistency between the title and content, which can be effectively used to analyze short texts in general.

Isogeometric Shape Design Sensitivity Analysis of Mindlin Plates (민들린 평판의 아이소-지오메트릭 형상 설계민감도 해석)

  • Lee, Seung-Wook;Cho, Seonho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.4
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    • pp.255-262
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    • 2013
  • In this paper, a shape design sensitivity analysis(DSA) method is presented for Mindlin plates using an isogeometric approach. The isogeometric method possesses desirable advantages; the representation of exact geometry and the higher order inter-element continuity, which lead to the fast convergence of solution as well as accurate sensitivity results. Unlike the finite element methods using linear shape functions, the isogeometric method considers the exact normal vector and curvature of the CAD geometry, taking advantages of higher order NURBS basis functions. A selective reduced integration(SRI) technique is incorporated to overcome the difficulty of 'shear locking' phenomenon. This simple technique is surprisingly helpful for the accuracy of the isogeometric shape sensitivity without complicated formulation. Through the numerical examples of plate bending problems, the accuracy of the proposed isogeometric analysis method is compared with that of finite element one. Also, the isogeometric shape sensitivity turns out to be very accurate when compared with finite difference sensitivity.

Isolation of Human and Mouse Orthologue HPRT Genes by Transformation-Associated Recombination (TAR) cloning (TAR cloning 법에 의한 인간 및 마우스의 상동성 HPRT 유전자의 분리)

  • Do, Eun-Ju;Kim, Jae-Woo;Chung, Chung-Nam;Park, In-Ho;Leem, Sun-Hee
    • Journal of Life Science
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    • v.16 no.6
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    • pp.1036-1043
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    • 2006
  • The transformation-associated recombination (TAR) cloning technique allows selective isolation of chromosome regions or genes from complex genome. The procedure requires knowledge of relatively small genomic sequences that reside adjacent to the chromosome region of interest. This method involves homologous recombination during spheroplast transformation between genomic DNA and a TAR vector that has 5' and 3' gene targeting sequences (hooks). To examine whether TAR cloning can be applied to the isolation of gene homologues, we chose the HPRT genes from human and mouse genome. As results, the yield of positive clones for HPRT gene from human and mouse genome when using a TAR vector containing mHPRT hook or hHPRT hook was almost same level. Analysis of the gap regions in mHPRT revealed that they contain abnormalities that could result in instability of the sequences. In conclusion, we were able to use the TAR cloning technology to isolate gene homologue (orthologue) from nonidentical genome. Moreover, the use of the TAR cloning system may accelerate work on closing the remaining gaps in mammalian genome to achieve the goal of annotation of all mammalian genes.

Overproduction of Sodium Gluconate Using the Recombinant Aspergillus niger (재조합 Aspergillus niger에 의한 글루콘산나트륨의 산업적 생산)

  • 이선희;이현철;김대혁;양문식;정봉우
    • KSBB Journal
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    • v.13 no.2
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    • pp.214-219
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    • 1998
  • Polymerase chain reaction(PCR) was conducted to obtain the gene encoding glucose oxidase(GOD) from Aspergillus niger(ATCC 2110) and the DNA sequence determined was coincided with published GOD sequence from A. niger. Recombinant transforming vector containing GOD and hygromycin B(hyg.B) resistant gene(hph) was constructed and used for further transformation of A. niger ATCC 2110. Selectivity of hyg.B against A. niger differed depending on which media were used i.e., nutrient-rich media such as potato dextrose agar(PDA) and complete medium(CM) showed only 50% growth inhibition at 400 $\mu$m ml$^-1$ of hyg.B while the minimal media inhibited mycelial growth completely at 200 $\mu$m ml$^-1$ of hyg.B. Twenty to sixty putative transformants were isolated from the hyg.B-containing minimal top agar, transferred successively onto alternating selective and nonselective media for a mitotic stability of hyg.B resistance and, then, single-spored. Among the stable transformants, the transformant(GOD1-6) grown by flask culture showed the considerable increase of extracellular GOD activity, which was estimated to the degree of 50% - 100% comparing to that of wild type. Transformation of tGOD1-6 was resulted from integration of the vectors into heterologous as well as homologous regions of the A. niger genome. Southern blot analysis revealed that there were two independent integrations of vector into fungal genome and one into the GOD gene due to homologous recombination. In addition, GOD activity and sodium gluconate production when tGOD1-6 was fed-batch fermented were enhanced 11 fold and 2.25 fold, respectively, compared to that of the wild type.

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