• Title/Summary/Keyword: q-gram

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Estimation of Substring Selectivity in Biological Sequence Database (생물학 서열 데이타베이스에서 부분 문자열의 선적도 추정)

  • 배진욱;이석호
    • Journal of KIISE:Databases
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    • v.30 no.2
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    • pp.168-175
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    • 2003
  • Until now, substring selectivities have been estimated by two steps. First step is to build up a count-suffix tree, which has statistical information about substrings, and second step is to estimate substring selectivity using it. However, it's actually impossible to build up a count-suffix tree from biological sequences because their lengths are too long. So, this paper proposes a novel data structure, count q-gram tree, consisting of fixed length substrings. The Count q-gram tree retains the exact counts of all substrings whose lengths are equal to or less than q and this tree is generated in 0(N) time and in site not subject to total length of all sequences, N. This paper also presents an estimation technique, k-MO. k-MO can choose overlapping length of splitted substrings from a query string, and this choice will affect accuracy of selectivity and query processing time. Experiments show k-MO can estimate very accurately.

A Series of IncQ-Based Reporter Plasmids for Use in a Range of Gram-Negative Genera

  • O'Sullivan, Laura E.;Nickerson, Cheryl A.;Wilson, James W.
    • Journal of Microbiology and Biotechnology
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    • v.20 no.5
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    • pp.871-874
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    • 2010
  • Many studies require expression analysis of the same gene/promoter across a range of bacterial genera. However, there is currently a lack of availability of reporters based on the broad-host-range IncQ replicon, which is compatible with a popular improved IncP transfer system that is self-transfer defective. We report IncQ lacZ reporter plasmids with features including (1) compatibility with IncP, IncW, and pBHR/pBBR replicons, (2) a variety of antibiotic markers (Sp-r, Sm-r, Km-r, Cm-r), (3) convenient mobilization via a novel self-transfer-defective IncP conjugation system, and (4) GenBank DNA sequences. Utility is demonstrated using three different promoters in different Gram-negative genera.

An Efficient String Similarity Search Technique based on Generating Inverted Lists of Variable-Length Grams (가변길이 그램의 역리스트 생성을 이용한 효율적인 유사 문자열 검색 기법)

  • Kim, Jongik
    • Journal of KIISE
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    • v.43 no.11
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    • pp.1275-1280
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    • 2016
  • Existing techniques for string similarity search first generate a set of candidate strings and then verify the candidates. The efficiency of string similarity search is highly dependent on candidate generation methods. State of the art techniques select fixed length q-grams from a query string and generate candidates using inverted lists of the selected q-grams. In this paper, we propose a technique to generate candidates using variable length grams of a query string and develop a dynamic programming algorithm that selects an optimal combination of variable length grams from a query string. Experimental results show that the proposed technique improves the performance of string similarity search compared with the existing techniques.

Isolation and Identification of a Photosynthetic Bacterium Containing $Q_{10}$ ($Q_{10}$ 함유 광합성세균의 분리 및 동정)

  • Jeong, Soo Kyoung;Kim, Joong Kyun
    • Journal of Marine Bioscience and Biotechnology
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    • v.2 no.2
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    • pp.120-122
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    • 2007
  • A $Q_{10}$-producing photosynthetic bacterium was isolated from the silt at Nakdong river. The isolate had 1.55 mg of $Q_{10}$ per gram of dry cell. By the 16s-rDNA sequence analysis, the isolate was found to be Rhodobacter sphaeroids with 100% similarity (Genbank Accession No.=AM696701).

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Mining Regular Expression Rules based on q-grams

  • Lee, Inbok
    • Smart Media Journal
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    • v.8 no.3
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    • pp.17-22
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    • 2019
  • Signature-based intrusion systems use intrusion detection rules for detecting intrusion. However, writing intrusion detection rules is difficult and requires considerable knowledge of various fields. Attackers may modify previous attempts to escape intrusion detection rules. In this paper, we deal with the problem of detecting modified attacks based on previous intrusion detection rules. We show a simple method of reporting approximate occurrences of at least one of the network intrusion detection rules, based on q-grams and the longest increasing subsequences. Experimental results showed that our approach could detect modified attacks, modeled with edit operations.

Antibacterial Activity and Cream Stability of Quercus salicina Blume Extract (참가시나무 추출물의 항균 활성 및 크림 안정성 평가)

  • Gu, Hyun A;Kim, Hae Soo;Park, Soo Nam
    • Microbiology and Biotechnology Letters
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    • v.42 no.2
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    • pp.145-151
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    • 2014
  • The antibacterial effect of Quercus salicina Blume extract was investigated and then the stability of a cream containing it best performing fraction, the ethyl acetate fraction, was evaluated. The antibacterial effect was evaluated on the skin microorganisms Staphylococcus aureus, Bacillus subtilis, Propionibacterium acnes, Escherichia coli, and Pseudomonas aeruginosa. Among the Q. salicina Blume extract fractions, the ethyl acetate fraction demonstrated the lowest minimum inhibitory concentration against S. aureus (1,200 ${\mu}g/ml$), B. subtilis (2,500 ${\mu}g/ml$), P. acnes (1,200 ${\mu}g/ml$) and P. aeruginosa (312 ${\mu}g/ml$). Therefore, a cream containing 0.25% ethyl acetate fraction of Q. salicina Blume extract was prepared and evaluated for stability. The pH, viscosity, and absorbance of the cream were measured under various temperatures (4, 20, 37, $45^{\circ}C$) and sun light during a 12 week period. The changes in viscosity, absorbance and pH of the cream did not change significantly during the term of the experiment when compared with a placebo cream. In addition, any change in color or odor of the cream was not observed during the 12 weeks. These results indicate that the ethyl acetate fraction of Q. salicina Blume extract has a high antibacterial effect and is stable as a cream. There is therefore some potential for its use in cosmetic materials.

Antimicrobial Activities of LB20304a, a New Quinolone Antibiotic

  • Kwak, Jin-Hwan;Kim, Mu-Yong;Paek, Kyoung-Sook;Kwon, Oh-Hun;Lee, Kyung-Won;Kim, In-Chull
    • Biomolecules & Therapeutics
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    • v.4 no.4
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    • pp.378-384
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    • 1996
  • In vitro activities of LB20304a were compared with those of grepafloxacin (OPC-17116), Q-35, ciprofloxacin, and sparfloxacin against 380 clinical isolates collected from general hospitals in 1996. LB 20304a was the most active agent against gram-positive strains including staphylococci, streptococci and enterococci. LB20304a was also very active against gram-negative bacteria and its activity was comparable to that of ciprofloxacin but better than those of grepafloxacin, Q-35 and sparfloxacin. The therapeutic effect of LB20304a was superior to those of sparfloxacin and ciprofloxacin against systemic infection by methicillin-resistant Staphylococcus aureus K283 (MRSA) in neutropenic mice. Against urinary tract infection induced by Escherichia coli 851E in mice, LB20304a was more active than sparfloxacin and ciprofloxacin. However, LB 20304a was slightly less active than that of ciprofloxacin against urinary tract infection by Pseudomonas aeruginosa 1912E, but better than that of sparfloxacin.

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Antioxidant Properties of Lentinula edodes after Sawdust Bag Cultivation with Different Oak Substrates (참나무 수종별 톱밥재배에 따른 표고의 항산화 특성)

  • Seo, Sooyoung;Park, Youngae;Jang, Yeongseon;Ka, Kang-Hyeon
    • The Korean Journal of Mycology
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    • v.45 no.2
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    • pp.121-131
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    • 2017
  • We evaluated the antioxidant properties of Lentinula edodes upon sawdust bag cultivation with 5 oak substrates: Quercus acutissima, Q. mongolica, Q. serrata, Q. aliena, and Q. variabilis. We found that the optimal extraction conditions were 70% (v/v) methanol shaken at 150 rpm at $25^{\circ}C$ and 150 rpm for 24 h. The methanolic extracts from L. edodes contained high phenolic and flavonoid contents, they also exhibited stronger antioxidant activities. The total phenolic contents and total flavonoid contents of the mushroom extracts ranged from 2.37 to 3.12 milligrams of gallic acid equivalents per gram of dried mushroom (mg GAE/g) and 0.48 to 0.48 milligrams of quercetin equivalents per gram of dried mushroom (mg QE/g), respectively. In addition, the mushroom extracts exhibited 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (15.8% to 89.4%) at 2 to 10 mg/mL, ferric reducing antioxidant power (0.153 to 0.425) at 5 to 20 mg/mL, and reducing power (0.078 to 0.359) at 5 to 20 mg/mL, respectively. Q. aliena more effectively increased total phenolic contents, total flavonoid contents, and antioxidant activities than the other oak substrates.

THE EXISTENCE THEOREM OF ORTHOGONAL MATRICES WITH p NONZERO ENTRIES

  • CHEON, GI-SANG;LEE, SANG-GU;SONG, SEOK-ZUN
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.4 no.1
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    • pp.109-119
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    • 2000
  • It was shown that if Q is a fully indecomposable $n{\times}n$ orthogonal matrix then Q has at least 4n-4 nonzero entries in 1993. In this paper, we show that for each integer p with $4n-4{\leq}p{\leq}n^2$, there exist a fully indecomposable $n{\times}n$ orthogonal matrix with exactly p nonzero entries. Furthermore, we obtain a method of construction of a fully indecomposable $n{\times}n$ orthogonal matrix which has exactly 4n-4 nonzero entries. This is a part of the study in sparse matrices.

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Whole genome sequence analysis of Ligilactobacillus agilis C7 isolated from pig feces revealed three bacteriocin gene clusters

  • Jeong Min, Yoo;Remilyn M., Mendoza;In-Chan, Hwang;Dae-Kyung, Kang
    • Journal of Animal Science and Technology
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    • v.64 no.5
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    • pp.1008-1011
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    • 2022
  • We here report the whole genome sequence of Ligilactobacillus agilis C7 with anti-listerial activity, which was isolated from pig feces. The genome size of L. agilis C7 (~ 3.0 Mb) is relatively larger compared with other L. agilis strains. L. agilis C7 carries three bacteriocin gene clusters encoding garvicin Q, salivaricin A, and Blp family class II bacteriocin. Garvicin Q and salivaricin A are reported to be active against Listeria monocytogenes and Micrococcus luteus, respectively, as well as against other Gram-positive bacteria. Meanwhile, the bacteriocin encoded in the blp cassette was shown to be active against pneumococci, mediating intraspecies competition. This report highlights the potential of L. agilis C7 for the production of bacteriocins inhibiting pathogenic bacteria.