Detection of Antistaphylococcal and Toxic Compounds by Biological Assay Systems Developed with a Reporter Staphylococcus aureus Strain Harboring a Heat Inducible Promoter - lacZ Transcriptional Fusion

Chanda, Palas Kumar,Ganguly, Tridib,Das, Malabika,Lee, Chia Yen,Luong, Thanh T.,Sau, Subrata Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.6

Previously it was reported that promoter of groES-groEL operon of Staphylococcus aureus is induced by various cellwall active antibiotics. In order to exploit the above promoter for identifying novel antistaphylococcal drugs, we have cloned the promoter containing region ($P_g$) of groES-groEL operon of S. aureus Newman and found that the above promoter is induced by sublethal concentrations of many antibiotics including cell-wall active antibiotics. A reporter S. aureus RN4220 strain (designated SAU006) was constructed by inserting the $P_g$-lacZ transcriptional fusion into its chromosome. Agarose-based assay developed with SAU006 shows that $P_g$ in single-copy is also induced distinctly by different classes of antibiotics. Data indicate that ciprofloxacin, rifampicin, ampicillin, and cephalothin are strong inducers, whereas, tetracycline, streptomycin and vancomycin induce the above promoter weakly. Sublethal concentrations of ciprofloxacin and ampicilin even have induced $P_g$ efficiently in microtiter plate grown SAU006. Additional studies show for the first time that above promoter is also induced weakly by arsenate salt and hydrogen peroxide. Taken together, we suggest that our simple and sensitive assay systems with SAU006 could be utilized for screening and detecting not only novel antistaphylococcal compounds but also different toxic chemicals.

Merge or Move

Yoon, Sau In 대한언어학회 1998 언어학 Vol.6 No.1

Yoon, Sau-In. 1998. Merge or Move. Linguistics, 6-1, 329-352. The paper briefly reviews the structure-building mechanism and the structure-modifying mechanism in generative grammar. In the Minimalist Program developed by Chomsky (1993, 1994, 1995), the former is called Merge and the latter Move/Attract. The present research argues against the claim that Merge is always selected over Move (Chomsky 1995, Yang 1997, Yang, et al. 1998) when the two operations are equally applicable, and proposes the "local" principle called "as many features as possible" (AMFAP) for controlling the application of Merge and Move. I argue that AMFAP is superior to Collins' (1997) Chain-Formation Principle, and show that it provides a systematic explanation of English expletive and superraising constructions. (Kyungwon College).

On Global Economy Conditions

윤서인 경원전문대학 1999 論文集 Vol.21 No.-

이 논문의 목적은 최소주의 틀 구조의 원리와 조건의 비 국부적(global)본질과 관련된 문제를 토의하고 몇 가지 대안적인 국부적(local)원리를 제안하고자 하는 것이다. 촘스키(1993, 1995)에 의해서 발전된 최소주의 프로그램에는 Last Resort와 Procrastinate와 같이 비 국부적 성질을 가지고 있는 많은 원리와 조건들이 있다. 최소주의 프로그램에서는 외현적 이동을 내현적 이동보다 값이 더 드는 이동으로 보고있다. 따라서 도출(convergence)이 요구되지 않는 경우에는 외현적 작용의 적용을 피하는 것이 개념상 필요하다. 이 연구 논문에서는 도출의 비 국부적 개념과 관련된 경제 조건은 적절치 못하기 때문에 문법에서 제거되어야 한다는 것과 영어의 초 인상구조에 근거를 두고 비용이 들지 않는 병합(merge)이 비용이 많이 드는 이동(move)보다 우선되어야 한다는 논리가 반드시 그렇지는 않다는 것을 논의하고 있다. 또한 Collins (1997)의 "local" Minimality Principle이 허사의 구조를 설명할 수 있다고 하지만 초 인상구조를 설명하는데는 적절치 못함을 논의하고 촘스키(1998)의 강순환 가설(Strong Cyclic Hypothesis)이 영어의 허사와 초 인상구조를 설명할 수 있음을 밝히고 있다.

비한정 기술의 중의성에 관하여

윤서인,이원빈 경원전문대학 2000 論文集 Vol.22 No.-

The aim of this paper is to present a unified approach to the indefinite descriptions in English in the relevant theoretic framework proposed by Sperber and Wilson (1986, 1995). As several linguists have pointed out, the indefinite descriptions are interpreted in two ways: attributive and referential meaning. However, this attributive-referential distinction is not adequate to explain the ambiguous reading of indefinite descriptions. We adopt the notion of looseness of speaking in the relevance theory of Sperber and Wilson, and show the appropriate account of the ambiguity of indefinite descriptions.

Studies on Synonymous Codon and Amino Acid Usage Biases in the Broad-Host Range Bacteriophage KVP40

Sau Keya,Gupta Sanjib Kumar,Sau Subrata,Mandal Subhas Chandra,Ghosh Tapash Chandra The Microbiological Society of Korea 2007 The journal of microbiology Vol.45 No.1

In this study, the relative synonymous codon and amino acid usage biases of the broad-host range phage, KVP40, were investigated in an attempt to understand the structure and function of its proteins/protein-coding genes, as well as the role of its tRNAs. Synonymous codons in KVP40 were determined to be AT-rich at the third codon positions, and their variations are dictated principally by both mutational bias and translational selection. Further analysis revealed that the RSCU of KVP40 is distinct from that of its Vibrio hosts, V. cholerae and V. parahaemolyticus. Interestingly, the expression of the putative highly expressed genes of KVP40 appear to be preferentially influenced by the abundant host tRNA species, whereas the tRNAs expressed by KVP40 may be required for the efficient synthesis of all its proteins in a diverse array of hosts. The data generated in this study also revealed that KVP40 proteins are rich in low molecular weight amino acid residues, and that these variations are influenced primarily by hydropathy, mean molecular weight, aromaticity, and cysteine content.

Studies on Synonymous Codon and Amino Acid Usage Biases in the Broad-Host Range Bacteriophage KVP40

Keya Sau,Sanjib Kumar Gupta,Subrata Sau,Subhas Chandra Mandal,Tapash Chandra Ghosh 한국미생물학회 2007 The journal of microbiology Vol.45 No.1

In this study, the relative synonymous codon and amino acid usage biases of the broad-host range phage, KVP40, were investigated in an attempt to understand the structure and function of its proteins/proteincoding genes, as well as the role of its tRNAs. Synonymous codons in KVP40 were determined to be ATrich at the third codon positions, and their variations are dictated principally by both mutational bias and translational selection. Further analysis revealed that the RSCU of KVP40 is distinct from that of its Vibrio hosts, V. cholerae and V. parahaemolyticus. Interestingly, the expression of the putative highly expressed genes of KVP40 appear to be preferentially influenced by the abundant host tRNA species, whereas the tRNAs expressed by KVP40 may be required for the efficient synthesis of all its proteins in a diverse array of hosts. The data generated in this study also revealed that KVP40 proteins are rich in low molecular weight amino acid residues, and that these variations are influenced primarily by hydropathy, mean molecular weight, aromaticity, and cysteine content.

Cloning and Sequencing Analysis of the Repressor Gene of Temperate Mycobacteriophage L1

Sau, Subrata,Chattoraj, Partho,Ganguly, Tridib,Lee, Chia Yen,Mandal, Nitai Chandra Korean Society for Biochemistry and Molecular Biol 2004 Journal of biochemistry and molecular biology Vol.37 No.2

The wild-type and temperature-sensitive (ts) repressor genes were cloned from the temperate mycobacteriophage L1 and its mutant L1cIts391, respectively. A sequencing analysis revealed that the $131^{st}$ proline residue of the wild-type repressor was changed to leucine in the ts mutant repressor. The 100% identity that was discovered between the two DNA regions of phages L1 and L5, carrying the same sets of genes including their repressor genes, strengthened the speculation that L1 is a minor variant of phage L5 or vice versa. A comparative analysis of the repressor proteins of different mycobacteriophages suggests that the mycobacteriophage-specific repressor proteins constitute a new family of repressors, which were possibly evolved from a common ancestor. Alignment of the mycobacteriophage-specific repressor proteins showed at least 7 blocks (designated I-VII) that carried 3-8 identical amino acid residues. The amino acid residues of blocks V, VI, and some residues downstream to block VI are crucial for the function of the L1 (or L5) repressor. Blocks I and II possibly form the turn and helix 2 regions of the HTH motif of the repressor. Block IV in the L1 repressor is part of the most charged region encompassing amino acid residues 72-92, which flanks the putative N-terminal basic (residues 1-71) and C-terminal acidic (residues 93-183) domains of L1 repressor.

The Effect of Surface Environment on the Machanism of Metal Cutting (1st Report)

Sau, Nam Saup,Kim, Tae Young,Yang, Gyun Eui 전북대학교 공업기술연구소 1983 工學硏究 Vol.14 No.-

금속절삭에 있어서 표면환경이 금속절삭 기구에 미치는 영향을 사실적으로 고찰하였다. Rehbinder가 정의한 표면효과라고 하는 것은 표면활성제를 금속표면에 흡착시키고 가공물을 절삭하면 기계적 강도가 저하된다는 것이다. 본 논문에서는 가공면조도에 있어서 도포한 표면 활성제의 효과를 관찰하기 위하여 Al재의 밀링 실험을 실시하였고 또한 동의 이차원 저속절삭에 있어 Chip 생성기구에 대한 magic ink의 영향을 관찰하였다. 본 실험 조건하에서 milling 실험과 이차원 절삭에서 실험한 결과는 다음과 같다. 1) milling 절삭과 이차원 절삭에서 생성 Chip의 자유표면 위에 절삭유로서 magic ink, 다른 표면활성첨가재를 사용함으로서 표면조도의 차이가 절삭된 표면 위에 copied patterm을 이루게 되었다. 2) milling 실험에 의해서 copied pattern이 이동되었고 이동된 거리는 milling cutter edge의 접촉 길이와 근사적으로 같았다. 3) 생성 Chip의 자유표면 위에 magic ink를 도포함으로서 절삭저항과 chip 두께가 감소하였다. 4) 전단면 위의 전단응력은 변화되지 않았지만 전단변형율은 magic ink를 도포함으로 절삭력과 chip 두깨의 변화에 관계없이 감소되었다.

Spanwise bifurcations beneath the bluff-body instability modes

Sau, Amalendu,Peng, Y. F.,Hwang, R. R. American Institute of Physics 2016 Physics of fluids Vol.28 No.6

A Study on Characteristics of Surface in Peripheral Milling

Sau, Nam Saup,Yang, Gyun Eui 전북대학교 공업기술연구소 1982 工學硏究 Vol.12 No.-

원주에 절삭력이 붙은 밀렁카터로 공작물을 가공할 때 가공면의 조도 기하학적 형상 가공조건(직경, 치수, 각, 절삭속도, Feed, 가공재, 절삭유 등)의 영향을 받는다. 상향절삭과 하향절삭에 대해서도 각각 조도가 다르게 나타난다. Ralph Lacey는 아무런 이론적 해석없이 단순히 실험만을 하야 상향절삭에서의 가공물의 조도가 하향절삭의 경우에서 보다 적게 나타났음을 보고하였으며 M. E. Martellotti는 상향절삭과 하향절삭에 있어서 밀링카터와 가공물간의 운동을 기하학적으로 해석하였을 뿐이다. 본 연구에서는 실험치를 이론치와 비교 및 검토하였다. Table 1에서와 같이 절삭속도와 Feed만을 변화시키며 다른 조건은 상수로 취급하여 실험을 하였다. 본 실험에서 얻은 실험치와 이론적인 값을 비교하여 다음의 결론을 얻었다. 1. 상향절삭의 경우에는 구성인선 없이 시작되나 하향의 경우에는 구성인선을 갖고 시작되어 상향절삭이 보다 매끄러운 표면을 형성한다. 2. 실제조도는 이론치보다 크게 나타난다. 3. 절삭속도가 크면 조도는 향상된다. 4. 조도는 Feed에 거의 비례하여 크게 나타난다.