• Journal of fish pathology
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• v.6 no.1
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• pp.57-64
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• 1993

The properties and DNA structures of R plasmids differ depending on the species of the fish-pathogens Aeromonas hydrophila, A. salmonicida, Edwardsiella tarda, Enterococcus seriolicida, Pasteurella piscicida and Vibrio anguillarum. However, some R plasmids with the same resistance markers in similar DNA structures were found in A. hydrophila and E. tarda, as well as in A. hydrophila and A. salmonicida. R plasmids from V. anguillarum were classified into three groups according to their DNA structures. The first group was detected before 1977, the second from 1980 to 1983, and the third from 1989 to 1991. R plasmids have been retained within P. piscieida having the same DNA structures and detected at various locations and times. E. seriolicida strains carrying the same R plasmids, which were encoded with resistance to macrolide antibiotics(MLs), lincomycin(LIM), and TC, and to MLs, LIM, and CP. were distributed in yellowtail farms in various districts. The chloramphenicol-resistance(cat) gene of the R plasmids of P. piscicida was classified as CAT type I. The cat of the R plasmids of E, tarda. A. salmonicida was classified as type II. The cat of R plasmids of V. anguillarum was classified into two types. One type detected before 1977, was classified as CAT IV and the other type, detected after 1980, was classified as CAT II. Tetracycline-resistance (tet) V. anguillarum, isolated before 1977 and after 1981, was classified as Tet B and Tet G, respectively. The class D tet gene was widely distributed in R plasmids from fish-pathogens A. hydrophila, E. tarda, P. piscicida, and also V. anguillarum isolated after 1989.

• Journal of fish pathology
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• v.35 no.1
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• pp.47-56
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• 2022

Lincomycin as one of the lincosamides antibiotics have been mainly used in human and livestock fields, but have not been used in aquaculture. In this study, the distribution of minimum inhibitory concentration (MIC) values against lincomycin and the detection of the macrolide-lincosamide-streptogramin (MLS) resistance gene were confirmed in bacterial pathogens isolated from cultured olive flounder (Paralichthys olivaceus). Of the 107 strains isolated from Jeju, 36 strains of Gram-positive bacteria and 71 strains of Gram-negative bacteria were identified. Most of Streptococcus spp. was found to have a MIC value of less than or equal to 0.5 ㎍/mL, and Edwardsiella piscicida was found to have a MIC value higher than 1,024 ㎍/mL. V. harveyi and V. alginolyticus mostly showed MIC values of 256 ㎍/mL, but V. scophthalmi displayed values of 8~64 ㎍/mL. In the detection of MLS resistance gene, erm(B) was detected in 9 strains of Streptococcus spp., and erm(A) was confirmed in one strain.

• Korean Journal of Microbiology
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• v.47 no.3
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• pp.200-208
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• 2011

Most problematic antibiotic resistance mechanism for MLS (macrolide-lincosamide-streptogramn B) antibiotics encountered in clinical practice is mono- or dimethylation of specific adenine residue at 2058 (E. coli coordinate) of 23S rRNA which is performed by Erm (erythromycin ribosome resistance) protein through which bacterial ribosomes reduce the affinity to the antibiotics and become resistant to them. ErmSF is one of the four gene products produced by Streptomyces fradiae to be resistant to its own antibiotic, tylosin. Unlike other Erm proteins, ErmSF harbors idiosyncratic long N-terminal end region (NTER) 25% of which is comprised of arginine well known to interact with RNA. Furthermore, NTER was found to be important because when it was truncated, most of the enzyme activity was lost. Based on these facts, capability of NTER peptide to inhibit the enzymatic activity of ErmSF was sought. For this, expression system for two different proteins to be expressed in one cell was developed. In this system, two plasmids, pET23b and pACYC184 have unique replication origins to be compatible with each other in a cell. And expression system harboring promoter, ribosome binding site and transcription termination signal is identical but disparate amount of protein could be expressed according to the copy number of each vector, 15 for pACYC and 40 for pET23b. Expression of NTER peptide in pET23b together with ErmSF in pACYC 184 in E. coli successfully gave more amounts of NTER than ErmSF but no inhibitory effects were observed suggesting that there should be dynamicity in interaction between ErmSF and rRNA rather than simple and fixed binding to each other in methylation of 23S rRNA by ErmSF.

• Korean Journal of Microbiology
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• v.42 no.3
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• pp.165-171
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• 2006

ERM proteins transfer the methyl group to $A_{2058}$ in 23S rRNA to confer the resistance to MLS (macrolide-lincosamide-streptogramin B) antibiotics on microorganism ranging from antibiotic producers to pathogens. To define the functional role of peptide segment encompassing amino acid residues 1 to 25 in NTER (N-terminal end region) of ErmSF, one of the ERM proteins, DNA fragment encoding mutant protein deprived of that peptide was cloned and overexpressed in E. coli to obtain a purified soluble form protein to the apparent homogeneity in the yield of 12.65 mg per liter of culture. The in vitro activity of mutant protein was found to be 85% compared to wild type ErmSF, suggesting that this peptide interact with substrate to affect the enzyme activity. This diminished activity of mutant protein caused the delayed expression of antibiotic resistance in vivo, that at fIrst cells expressing mutant protein showed the retarded growth due to the antibiotic action but with time cells inhibited by antibiotic gradually recovered the viability to exert the resistance to the same extent as those with wild type protein.

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.10-11
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• 2003

완전 광 레이블 스위칭 기술은 차세대 광 인터넷에서 요구되는 투명성과 낮은 latency를 주기 위한 핵심기술이다. 패킷 스위칭 시스템은 각 노드에서 레이블을 이용해 패킷을 교환하는 방식으로 각 라우터에서는 이전 라우터에서 전달해 은 레이블을 분석하고 그 레이블 신호에 따라서 목적지로 포워딩 시키게 된다. 레이블을 교환하는 기술은 MLS 또는 완전 광 레이블 스위칭 (Optical label Switching： OLS) 네트웍에서 scalability를 구현하기 위한 핵심 기술이 된다. (중략)

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.3 s.96
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• pp.320-328
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• 2005

Last target of architectural acoustics is that people wish to convey voice effectively from the space adaptively in use purpose in building. But, how exactly through space sound (sound source) that wish to deliver from indoor can be passed method to do quantification and evaluate quantity of sound by method to serve indoor architectural acoustics estimation summer period and methods to estimate definition propose. This Study searches special quality of sound source about MLS signal that is occurred short-answer sound source (pistol sound source) and nondirectional speaker among indoor sound estimation method, and measure and analyzed reverberation time (RT60), definition (C80, D50) by regulation of each ISO 3382 in age place (classroom, hall, gymnasium). Analysis result and sound factor among could know that d of two sound sources converges in measurement error extent about reverberation time (RT60) of analysis incidental and sound factors and value shows change irregularly about sound factor of D50, C80, pistol sound source judged there is problem. Also, could know that problem is happened in deflection except reverberation time is in deflection analysis with wave that measure each in fixed distance in branch. Finally, when differ size of sound source and measure about change of sound pressure level in case measure sound pressure level giving difference about 10 dB, sound factor could know that there is no different effect.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.1
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• pp.33-37
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• 2013

The properties of LTCC green sheets formed by the MLS-22 powder of NEG Inc. were investigated for acrylic binders with different PVB and Tg in the variation of temperature. The elongation of the green sheets showed large variation depending on the temperature, and was rapidly decreased near the Tg of the sheets. With the increase of the ratio of plasticizer/binder (P/B), large elongation of the sheets was observed due to the decrease of the Tg. In the stacking process of the multilayer ceramic, the optimal control of the temperature is highly required depending on the Tg of the binder and the ratio of P/Buniform coating.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.9
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• pp.1947-1954
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• 2011

There are various attacks such as tampering, bypassing and spoofing which are caused with system-wide vulnerabilities of Windows operating system. The underlying operating system is responsible for protecting application-space mechanisms against such attacks. This paper provides the implementation of mandatory access control known as multi-level security (MLS) rating with TCSEC-B1 level on th kernel of Windows$^{TM}$. By adding especially the protection feature against tampering memory of processes to the security kernel, this implementation meets the responsibility against system-wide vulnerabilities.

• The Journal of the Acoustical Society of Korea
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• v.25 no.3E
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• pp.95-100
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• 2006

The present study presents the design procedures and the acoustic properties of the main hall of Ansan Cultural Arts Center in Korea which has opened in 2004. The acoustic design values are compared with the measured acoustic properties of the completed multi-purpose hall. Acoustic design criteria were suggested in the design stage through the 3-dimentional computer simulations. The acoustic parameters including SPL, RT, C80, $D_{50}$M, RASTI were measured in the hall after completed. Acoustic measurements were carried out in the 40 measurement points using MLS sound source signal in 4 different sound source points. The results show the even distribution of sound levels within the 2.0dB of difference among all seats. The reverberation time of 1.66sec was measured which is similar to the objective value of 1.65 sec in empty states. It was also found that average C80 values lie in the objective extents of C80 from -1 to 3dB and average D50 value of 54 was measured. Thus, it is concluded that the hall can be used as a multi-purpose hall with a suitable acoustic conditions.

• Korean Journal of Microbiology
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• v.37 no.4
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• pp.253-258
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• 2001

A Bacillus circulans KCTC3004 $\beta$-1,3-glucanase gene contained in a recombinant plasmid pLM460 derived from subcloning the original recombinant plasmid pLM530 was trasferred into a new shuttle vector plasmid pLMS1180 by ligating linearized DNAs of pLM460 and pUB110. B. subtilis RM125 and B. megaterium ATCC14945 transformed with pLMS1180 produced the $\beta$-1,3-glucanase substantially. Most of the enzyme was produced during the exponential growth period. The maxium activities of the $\beta$-1,3-glucanase produced by the Bacillus transformants were compared with that of the B. circulans gene donor strain. The B. subtilis RM125 (pLM1180) enzyme showed the activity 14 times higher than that of the gene donor cells, followed by the B. megaterium ATCC14945 (pLMS 1180) enzyme with activity 5 times higher than that of the gene donor cells. While E. coli secreted about 7% of the produced enzyme, B. subtilis excreted the enzyme into the medium wholly and B. megaterium about 97% of the total product. The SDS-PAGE of this enzyme produced in E. coli (pLMS1180), B subtilis (pLMS1180) or B. megaterium (pLMS1180) indicated a molecular weight of 38,000. The enzymes overproduced in three different host cells hydrolyzed laminarin to produce mainly laminaribiose, laminaritriose, and laminarioligosaccharides. The plasmid pLMS1180 was stable in B. megaterium, E. coli, but was unstable in B. subtilis.