• 제목/요약/키워드: Lambda Expression

검색결과 74건 처리시간 0.025초

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

  • Suh, Joo-Won;Price, Chester
    • 미생물과산업
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    • 제14권1호
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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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Implications of Exonuclease Activity of Bacteriophage P2 Old Protein for Lambda Exclusion

  • Kim, Kwang-Ho;Park, Chan-Hee;Yeo, Hyeon-Joo;Kee, Young-Hoon;Park, Jung-Chan;Myung, Hee-Joon
    • Journal of Microbiology and Biotechnology
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    • 제10권2호
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    • pp.272-274
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    • 2000
  • Temperate bacteriophage P2 has a nonessential gene called old(overcoming lysoginization defection). In the presence of old, the growth of the host (Escherichia coli) with recBC- genotype is ingibited, and another bacteriophage, lambda, cannot superinfect. The Old protein has been shown to possess an exonuclease actibity. Three mutant P2s(old 1, old 17, old 49) which did gene was coned into expression vectors to produce hexahistidine-tagged proteins. The proteins were affinity-purified and shown to lose its exonuclease activity on both double-stranded and single-stranded DNA substrates. Thus, it was concluded that the lambda exclusion was related to Old's exonuclease activity.

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A two-stage service policy for an M/G/1 queueing system

  • Kim, Jongwoo;Song, Mi Jung;Lee, Jiyeon
    • Journal of the Korean Data and Information Science Society
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    • 제24권4호
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    • pp.941-948
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    • 2013
  • We introduce the $P^M_{{\lambda},{\tau}}$ service policy, as a generalized two-stage service policy of the $P^M_{\lambda}$ policy of Bae et al. (2002) for an M/G/1 queueing system. By using the level crossing theory and solving the corresponding integral equations, we obtain the explicit expression for the stationary distribution of the workload in the system.

Protein Kinase $C\alpha$ Is Involved in the Cell Condensation During Chondrogenesis in Vitro

  • Lim, Young-Bin;Kang, Shin-Sung;Lee, young-Sup;Sonn, Jong-Kyung
    • Animal cells and systems
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    • 제4권4호
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    • pp.361-366
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    • 2000
  • In order to investigate the role of protein kinase C (PKC) in chondrogenic differentiation, we examined the localization of PKC isoforms in a limb bud micromass culture system. PKC$\alpha$ is specifically localized in the regions which would become cartilage nodules, while PKC$\lambda/l$ and $\zeta$ display widespread distribution in the whole culture. Distribution of PKC$\alpha$ change along with promotion or inhibition of chondrogenesis by lysophosphatidylcholine or phorbol 12-myristate 13-acetate. On the other hand, localization of PKC$\lambda/l$ or $\zeta$ a was not changed by the modulation of chondrogenesis. Peanut agglutinin binding protein which is associated with cell aggregation during chondrogenesis was present in the cell condensation regions and its expression in those regions was influenced by PKC activity. Expression of fibronectin and N-cadherin in the cell condensing area were also affected by modulation of PKC activity. These results suggest involvement of PKC$\alpha$ in the cell condensation, possibly through regulating expression of fibronectin and N-cadherin.

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Development of a Simple Cell Lysis Method for Recombinant DNA Using Bacteriophage Lambda Lysis Genes

  • Jang, Bo-Yun;Jung, Yun-A;Lim, Dong-Bin
    • Journal of Microbiology
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    • 제45권6호
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    • pp.593-596
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    • 2007
  • In this study, we describe the development of a simple and efficient method for cell lysis via the insertion of a bacteriophage lambda lysis gene cluster into the pET22b expression vector in the following order; the T7 promoter, a gene for a target protein intended for production, Sam7 and R. This insertion of R and Sam7 into pET22b exerted no detrimental effects on cellular growth or the production of a target protein. The induction of the T7 promoter did not in itself result in the autolysis of cells in culture but the harvested cells were readily broken by freezing and thawing. We compared the efficiency of the cell lysis technique by freezing and thawing to that observed with sonication, and determined that both methods completely disintegrated the cells and released proteins into the solution. With our modification of pET22b, the lysis of cells became quite simple, efficient, and reliable. This strategy may prove useful for a broad variety of applications, particularly in experiments requiring extensive cell breakage, including library screening and culture condition exploration, in addition to protein purification.

역전사효소(逆轉寫酵素) 유전자(遺傳子)의 cloning 에 관(關)한 연구(硏究) (Cloning of Reverse Transcriptase Gene of Avian Sarcoma Virus)

  • 김용웅;김광식;서용택
    • Applied Biological Chemistry
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    • 제31권3호
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    • pp.219-225
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    • 1988
  • Avian Sarcoma Virus의 plasmid DNA중(中)의 역 이사효소의 유전자(遺傳子)를 온도의존성(溫度依存性) 발현(發現) vector인 pPL-lambda에 cloning하여 온도(溫度)에 민감한 phage ${\lambda}$의 repressor인 cI857 gene을 갖고 있는 bacteriophage lysogen인 N4830에 transformation시켰다. transformant를 pL promoter의 발현(發現)을 억제(抑制)하는 저온(低溫)$(28^{\circ}C)$에서 배양(培養)시킨 뒤, 이 repressor를 억제(抑制)하여 transcription을 촉진(促進)하게 하는 고온(高溫)$(42^{\circ}C)$에서 배양(培養)시킨 다음 균체(菌體)를 회수(回收)하여 RNA를 추출(抽出)하고 분석(分析)을 한 결과(結果) 도입(導入)된 역전사 효소 유전자(遺傳子)의 전사(轉寫)가 고온(高溫)에서 증대(增大)되었다.

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[ $P_{\lambda,;,T}^M-policy$ ] of a finite dam with both continuous and Jumpwise inputs

  • Lim Kyung Eun;Baek Jee Seon;Lee Eui Yong
    • 한국통계학회:학술대회논문집
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    • 한국통계학회 2004년도 학술발표논문집
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    • pp.123-128
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    • 2004
  • A finite dam under $P_{\lambda,;,T}^M-policy$ is considered, where the input of water is formed by a Wiener process subject to random jumps arriving according to a Poisson process. Explicit expression is deduced for the stationary distribution of the level of water. And the long-run average cost per unit time is obtained after assigning costs to the changes of release rate, a reward to each unit of output, and a penalty which is a function of the level of water in the reservoir.

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스테레오 비젼에 의한 생체표면 3차원 복원의 최적화 연구 (A Study on the Optimization for Three Dimensional Reconstruction of Bio Surface Using by Stereo Vision)

  • 이경채;이언석
    • 전기학회논문지
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    • 제66권1호
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    • pp.107-113
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    • 2017
  • Unlike regular images, there is no ground truth for bio surface images. Result of biosurface imaging is not only significantly affected by the environment and the condition of the bio surface, it requires more detailed expression than regular images. Therefore, unlike algorithms tested on regular images, studies on bio surface images requires a highly precise optimization process. We aim to optimize the graph cut algorithm, known to be the most outstanding among the stereo visions, by considering baseline, lambda, and disparity range. Optimal results were in the range of 1~10 for lambda. The disparity ranged from -30 to -50, indicating an optimal value in a slightly higher range. Furthermore, we verified the tested optimization data using SIFT.

역가우스분포에 대한 적합도 평가를 위한 그래프 방법 (A Graphical Method to Assess Goodness-of-Fit for Inverse Gaussian Distribution)

  • 최병진
    • 응용통계연구
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    • 제26권1호
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    • pp.37-47
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    • 2013
  • Q-Q 플롯은 자료에 대한 분포적 가정을 평가하기 위해서 사용되는 편리하고 효과적인 그래프 방법이다. Q-Q 플롯은 자료의 분포와 이론적 분포를 비교하기 위한 확률플롯으로 자료에서의 분위수와 이에 대응하는 이론적 분위수를 각각 수직축과 수평축으로 해서 그린 산점도의 형태를 취한다. 본 논문에서는 확률변수 X가 위치모수 ${\mu}$와 척도수 ${\lambda}$를 가지는 역가우스분포를 따르면, 변환된 확률변수 $Y={\mid}\sqrt{\lambda}(X-{\mu})/{\mu}\sqrt{X}{\mid}$는 평균이 0이고 분산이 1인 표준반접정규분포를 하게 되는 분포적 결과를 활용하여 역가우스분포 Q-Q 플롯의 구축방법을 소개한다. 역가우스분포와 다른 분포를 따르는 자료를 대상으로 그린 Q-Q 플롯에서 나타나는 점들의 형태를 알아보고자 모의실험을 수행하고 그 결과를 제시한다. 실제 자료에 대한 사례분석을 통해 제안한 Q-Q 플롯의 유용성을 보인다.