• Title, Summary, Keyword: REC

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Characterization of Streptococcus pneumoniae recP and rec-8 Genes (폐염균 recP와 rec-8 유전자의 비교)

  • Kim, Seung-Hwan;Kim, Soo-Nam;Rhee, Dong-Kwon
    • YAKHAK HOEJI
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    • v.36 no.6
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    • pp.582-590
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    • 1992
  • S. pneumoniae recP mutant was compared with rec-8 mutant to identify whether they are the same gene or not by determining sensitivity to DNA damaging agents. recP and rec-8 mutant have almost same sensitivity to UV, ethylmethane sulfonate, and methylmethane sulfonate, suggesting that recP has the same function as the rec-8 gene in DNA repair.

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Eco-System: REC Price Prediction Simulation in Cloud Computing Environment (Eco-System: 클라우드 컴퓨팅환경에서 REC 가격예측 시뮬레이션)

  • Cho, Kyucheol
    • Journal of the Korea Society for Simulation
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    • v.23 no.4
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    • pp.1-8
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    • 2014
  • Cloud computing helps big data processing to make various information using IT resources. The government has to start the RPS(Renewable Portfolio Standard) and induce the production of electricity using renewable energy equipment. And the government manages system to gather big data that is distributed geographically. The companies can purchase the REC(Renewable Energy Certificate) to other electricity generation companies to fill shortage among their duty from the system. Because of the RPS use voluntary competitive market in REC trade and the prices have the large variation, RPS is necessary to predict the equitable REC price using RPS big data. This paper proposed REC price prediction method base on fuzzy logic using the price trend and trading condition infra in REC market, that is modeled in cloud computing environment. Cloud computing helps to analyze correlation and variables that act on REC price within RPS big data and the analysis can be predict REC price by simulation. Fuzzy logic presents balanced REC average trading prices using the trading quantity and price. The model presents REC average trading price using the trading quantity and price and the method helps induce well-converged price in the long run in cloud computing environment.

Study on Optimal Trading Method of REC by Solar Power Generation (태양광 REC 최적 거래 방식에 관한 연구)

  • Nam, Youngsik;Lee, Jaehyung
    • Environmental and Resource Economics Review
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    • v.29 no.1
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    • pp.91-111
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    • 2020
  • While the renewable energy portfolio standard (RPS) is in place to expand the scale of renewable energy generation, the power producer can obtain the renewable energy credit (REC) and use it as an incentive to operate the facility. RECs secured by solar power generation can be traded through spot market or fixed price contracts, and, in the spot market trading, power producers are exposed to the uncertainty of REC spot price. In this study, real option analysis is conducted to analyze the optimal threshold of REC spot price for the conversion of REC trading method by power producer considering the uncertainty of REC spot price. We calculated the optimal threshold of REC spot price that can convert the trading method of REC from spot market to fixed price contract. In conclusion, the spot market trading is a rational trading method when considering the uncertainty of REC price, but the fixed price bidding is a rational trading method when not considering the uncertainty of REC price.

Analysis of Double Stranded DNA-dependent Activities of Deinococcus radiodurans RecA Protein

  • Kim, Jong-Il
    • Journal of Microbiology
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    • v.44 no.5
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    • pp.508-514
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    • 2006
  • In this study, the double-stranded DNA-dependent activities of Deinococcus radiodurans RecA protein (Dr RecA) were characterized. The interactions of the Dr RecA protein with double-stranded DNA were determined, especially dsDNA-dependent ATP hydrolysis by the Dr RecA protein and the DNA strand exchange reaction, in which multiple branch points exist on a single RecA protein-DNA complex. A nucleotide cofactor (ATP or dATP ) was required for the Dr RecA protein binding to duplex DNA. In the presence of dATP, the nucleation step in the binding process occurred more rapidly than in the presence of ATP. Salts inhibited the binding of the Dr RecA protein to double-stranded DNA. Double-stranded DNA-dependent ATPase activities showed a different sensitivity to anion species. Glutamate had only a minimal effect on the double-stranded DNA-dependent ATPase activities, up to a concentration of 0.7 M. In the competition experiment for Dr RecA protein binding, the Dr RecA protein manifested a higher affinity to double-stranded DNA than was observed for single-stranded DNA.

A small recA analog in streptococcus pneumoniae that is not induced during competence for genetic transformation (폐염균에서 작은 RecA 유사체의 검출 및 형질전환 때의 비유도성 확인)

  • ;Morrison, Donald A.
    • Korean Journal of Microbiology
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    • v.27 no.2
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    • pp.162-167
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    • 1989
  • Western blot analysis of lysates of Streptococcus pneumoniae revealed a single polypeptide species that cross-reacted with E. coli RecA antiserum. The apparent molecular weight of this putative RecA protein analog (RecAsp) was 24, 000 smaller than any other known RecA analogue. The RecAsp protein was present at the same level in competent and non-competent cells.

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Characterization of Single Stranded DNA-Dependent ATPase Activities of Deinococcus radiodurans RecA Protein (Deinococcus radiodurans RecA 단백질의 외가닥 DNA-의존성 ATPase 활성 분석)

  • Kim, Jong-Il
    • Korean Journal of Microbiology
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    • v.43 no.4
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    • pp.250-255
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    • 2007
  • The RecA protein of Deinococcus radiodurans is essential for the extreme radiation resistance of this organism. The central steps involved in recombinational DNA repair require DNA-dependent ATP hydrolysis by recA protein. Key feature of RecA protein-mediated activities is the interactions with ssDNA and dsDNA. The ssDNA is the site where RecA protein filament formation nucleates and where initiation of DNA strand exchange takes place. The effect of sequence heterogeneity of ssDNA was examined in this experiment. The rate of homopolymeric synthetic ssDNA-dependent ATP hydrolysis was constant or nearly so over a broader range of pHs. For poly(dT)-dependent ATP or dATP hydrolysis, rates were generally faster, with a broader optimum between pH 7.0 and 8.0. Activities of RecA protein were affected by the ionic environment. The ATPase activity was shown to have different sensitivity to anionic species. The presence of glutamate seemed to slimulate the hydrolytic activity. Dr RecA protein was shown to require $Mg^{2+}$ ion greater than 2 mM for binding to etheno ssDNA and the binding stoichiometry of 3 nucleotide for RecA protein monomer.

Effects of Browning Reaction Products on DNA Damage (효소적 갈변 생성물의 DNA 손상에 대한 효과)

  • Lee, Ji-Eun;Kim, An-Keun
    • Korean Journal of Pharmacognosy
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    • v.31 no.2
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    • pp.240-244
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    • 2000
  • Antimutagenicity profiles of the enzymatic browning reaction products(EBRP) were investigated. The rec-assay with Bacillus subtilis strains $H17(rec^+)$ and $M45(rec^-)$ was carried out using their spores. The biological activities were evaluated for seven different enzymatic browning reaction products, which resulted from the reactions of seven polyphenols with polyphenol oxidase isolated from Ginkgo biloba leaves. In the spore $rec^-$ assay, most of the polyphenolic compounds tested were positive, whereas their enzymatic browning reaction products were tested negative. The mutagenicity of enzymic browning mixtures of the polyphenols and the enzymes obtained from Ginkgo biloba leaves showed negative results in the mutagenicity test using Bacillus subtilis strains $H17(rec^+)$ and $M45(rec^-)$. In the case where polyphenol oxidase inhibitors were added in the enzymatic reaction mixtures with polyphenols, the polyphenols showed mutagenic effect in the spore $rec^-$ assay. This suggests that the activity of polyphenol oxidase is decreased.

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Effect of Cobaltous Chloride on the Repair of UV-induced DNA Damage (UV에 의해 손상된 DNA 회복에 미치는 cobaltous chloride의 효과)

  • Kim, Kug-Chan;Kim, Yung-Jin;Lee, Kang-Suk
    • Journal of Radiation Protection and Research
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    • v.20 no.2
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    • pp.71-78
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    • 1995
  • To develop methods to reduce radiation risk and apply such knowledge to improvement of radiation protection, the effects of cobaltous chloride known as bioantimutagen on the function of E. coli RecA protein involved in the repair of DNA damage were examined. The results demonstrated two distinct effects of cobaltous chloride on the RecA protein function necessary for the strand exchange reaction. Cobaltous chloride enhanced the ability of RecA protein to displace SSB protein from single-stranded DNA and the duplex DNA-dependent ATPase activity. RecA protein was preferentially bound with UV-irradiated supercoiled DNA as compared with nonirradiated DNA The binding of RecA protein to UV-irradiated supercoiled DNA was enhanced in a dose-dependent manner. It is likely that studies on the factors affecting repair efficiency and the DNA repair proteins may provide information on the repair of ionizing radiation-induced DNA damage and the mechanism for DNA radioprotection.

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A Yeast MRE3/REC114 Gene is Essential for Normal Cell Growth and Meiotic Recombination

  • Leem, Sun-Hee
    • Journal of Microbiology
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    • v.37 no.4
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    • pp.248-255
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    • 1999
  • We have analyzed the MRE3/REC114 gene of Saccharomyces cerevisiae, previously detected in isolation of mutants defective in meiotic recombination. We cloned the MRE3/REC114 gene by complementation of the meiotic recombination defect and it has been mapped to chormosome XIII. The DNA sequence analysis revealed that the MRE3 gene is identical to the REC114 gene. The upstream region of the MRE3/REC114 gene contains a T_4C site, a URS (upstream repression sequence) and a TR (T-rich) box-like sequence, which reside upstream of many meiotic genes. Coincidentally, northern blot analysis indicated that the three sizes of MRE3/REC114 transcripts, 3.4, 1.4 and 1.2 kb, are induced in meiosis. A less abundant transcript of 1.4 kb is detected in both mitotic and meiotic cells, suggesting that it is needed in mitosis as well as meiosis. To examine the role of the MRE3/REC114 gene, we constructed mre3 disruption mutants. Strains carrying an insertion or null deletion of the MRE3/REC114 gene showed slow growth in nutrient medium and the doubling time of these cells increased approximately by 2-fond compared to the wild-type strain. Moreover, the deletion mutant (${\delta}$mre3) displayed no meiotically induced recombination and no viable spores. The mre3/rec114 spore lethality can be suppressed by spo13, a mutation that causes cells to bypass reductional division. The double-stranded breaks (DSBs) which are involved in initiation of meiotic recombination were not detected in the analysis of meiotic chromosomal DNA from the mre3/rec114 disruptant. From these results we suggest that the MRE3/REC114 gene product is essential in normal growth and in early meiotic stages involved in meiotic recombination.

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Influence of Electronic-cigarette Smoke on Cardiac Autonomic Nerve Responses in Comparison with Conventional-cigarette Smoke (전자담배흡연이 심장자율신경조절에 미치는 반응: 궐련담배와의 비교 검증)

  • Kim, Choun Sub;Kim, Maeng Kyu
    • Journal of Life Science
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    • v.28 no.5
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    • pp.587-596
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    • 2018
  • This study aims to observe changes in heart-rate variability (HRV) indices induced by e-cigarette and conventional-cigarette smoking and to compare the differences in acute cardiac autonomic regulation. All participants (n=41) were exposed to both e-cigarette smoke (ES) and conventional cigarette smoke (CS) in a randomized crossover trial. HRV analysis was performed during each smoking session based on a recorded r-r interval 10 minutes before smoking and at specified recovery periods (REC1, 0-5 min; REC2, 5-10 min; REC3, 10-15 min; REC4, 15-20 min; REC5, 20-25 min; and REC6, 25-30 min). ES led to a significantly increased cardiac sympathetic index (LF/HF ratio) compared with the baseline, and it shifted the sympathovagal balance toward sympathetic predominance, including reduction in the complexity of the interbeat interval (SampEn). In REC1 after ES, only decreases of parasympathetic indices such as rMSSD, pNN50, HF, and SD1 were indicated. CS sessions produced not only an increased LF/HF ratio during smoking and recovery periods (REC1 and REC4) but also enhanced sympathetic predominance on autonomic balance during smoking and recovery periods (REC1, REC2, and REC4). In the CS trials, parasympathetic indices of time and non-linear analysis (rMSSD, pNN50, and SD1) were decreased during smoking and in REC1 to REC5. SampEn was also reduced during smoking and REC1 to REC4. Acute sympathoexcitatory effects induced by e-cigarette use produced statistically significant results. Parasympathetic withdrawal after smoking suggests that e-cigarettes may cause increased cardiovascular risk.