• 한국미생물·생명공학회지
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• 제17권2호
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• pp.131-135
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• 1989

Effects of the inoculum size of testing organism and pH of the plate and the concentration of agar were investigated for the selection of high kasugamycin producing mutants of Streptomyces kasugaensis ATCC 15114. For the detection of high kasugamycin-producing mutants, both concentrations of agar and test organism were optimized at the concentrations of 2% and 0.35 (A$_{550}$), respectively. The pH 7 was optimum for both growing the testing organism, Pseudomonas fluorescens IFO 12180, and for obtaining more promising mutant strains of S. kasugaensis. Under these conditions, mutants had been isolated which, tested later in liquid cultures, gave higher kasugamycin yields than that of the parent strain.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.452-455
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• 1999

We introduce an evolutionary approach to on-line learning for mobile robot control using reconfigurable hardware. We use genetic programming as an evolutionary engine. Control programs are encoded in tree structure. Genetic operators, such as node mutation, adapt the program trees based on a set of training cases. This paper discusses the advantages and constraints of the evolvable hardware approach to robot learning and describes a FPGA implementation of the presented genetic programming method.

• International Journal of Aeronautical and Space Sciences
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• 제14권4호
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• pp.341-349
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• 2013

This paper considers the optimum design of flexbeam cross-sections for a full-scale bearingless helicopter rotor, using an efficient hybrid optimization algorithm based on particle swarm optimization, and an improved genetic algorithm, with an effective constraint handling scheme for constrained nonlinear optimization. The basic operators of the genetic algorithm, of crossover and mutation, are revisited, and a new rank-based multi-parent crossover operator is utilized. The rank-based crossover operator simultaneously enhances both the local, and the global exploration. The benchmark results demonstrate remarkable improvements, in terms of efficiency and robustness, as compared to other state-of-the-art algorithms. The developed algorithm is adopted for two baseline flexbeam section designs, and optimum cross-section configurations are obtained with less function evaluations, and less computation time.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2004년도 추계학술대회
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• pp.171-178
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• 2004

This study suggests a general paradigm enhancing genetic mutability. Mutability among heterogeneous members in a genetic population has been a major problem in application of genetic programming to diverse business problems. This suggested paradigm is implemented to developing new methods from existing methods. Within the evolutionary approach taken to designing new methods, a general representation scheme of the genetic programming framework, called a kernel, is introduced. The kernel is derived from the literature of algorithms and heuristics for combinatorial optimization problems. The commonality and differences among these methods have been identified and again combined by following the genetic inheritance merging them. The kernel was tested for selected methods in combinatorial optimization. It not only duplicates the methods in the literature, it also confirms that each of the possible solutions from the genetic mutation is in a valid form, a running program. This evolutionary method suggests diverse hybrid methods in the form of complete programs through evolutionary processes. It finally summarizes its findings from genetic simulation with insight.

• 한국기계가공학회지
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• 제20권11호
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• pp.108-114
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• 2021

In this study, a multivariate function was applied to the genetic algorithm for D-type lugs currently used in shipyards to closely analyze the behavioral form of weight loss without double plates. An optimal lifting lug structure design without attachments is proposed. MATLAB R2016a was used to design features by applying multivariate functions to genetic algorithms. Furthermore, the design was achieved by deriving the optimal shapes of lugs using genetic algorithms. The shapes of the designed lugs were validated for structural bonding using the structural analysis program ANSYS 2020 R2, and a robust design of lugs with no appendages was developed.

• Biomolecules & Therapeutics
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• 제30권3호
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• pp.274-283
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• 2022

KRAS activating mutations, which are present in more than 90% of pancreatic cancers, drive tumor dependency on the RAS/mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/AKT signaling pathways. Therefore, combined targeting of RAS/MAPK and PI3K/AKT signaling pathways may be required for optimal therapeutic effect in pancreatic cancer. However, the therapeutic efficacy of combined MAPK and PI3K/AKT signaling target inhibitors is unsatisfactory in pancreatic cancer treatment, because it is often accompanied by MAPK pathway reactivation by PI3K/AKT inhibitor. Therefore, we developed an inRas37 antibody, which directly targets the intra-cellularly activated GTP-bound form of oncogenic RAS mutation and investigated its synergistic effect in the presence of the PI3K inhibitor BEZ-235 in pancreatic cancer. In this study, inRas37 remarkably increased the drug response of BEZ-235 to pancreatic cancer cells by inhibiting MAPK reactivation. Moreover, the co-treatment synergistically inhibited cell proliferation, migration, and invasion and exhibited synergistic anticancer activity by inhibiting the MAPK and PI3K pathways. The combined administration of inRas37and BEZ-235 significantly inhibited tumor growth in mouse models. Our results demonstrated that inRas37 synergistically increased the antitumor activity of BEZ-235 by inhibiting MAPK reactivation, suggesting that inRas37 and BEZ-235 co-treatment could be a potential treatment approach for pancreatic cancer patients with KRAS mutations.

• 한국임상수의학회지
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• 제32권1호
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• pp.1-4
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• 2015

개의 10번 염색체에 존재하는 Copper metabolism domain containing 1 (COMMD1) 유전자는 체내 구리 대사를 조절하는 COMMD1 단백질을 합성한다. COMMD1 유전자의 exon 2 결손변이는 단백질의 결핍을 유발하여 베들링턴 테리어 견종에서 상염색체 열성 유전질환인 구리 중독증을 일으킨다. 본 증에 이환된 개체는 담즙을 통한 구리의 배설이 저해되어 간 내에 구리가 축적된다. 본 연구에서는 국내 베들링턴 테리어 257두(수컷 109두, 암컷 148두) 혈액 시료를 사용하여 genomic DNA를 추출하였다. 유전자 결손변이의 분자생물학적 진단을 위해 다중 중합효소 연쇄반응법(multiplex PCR)을 이용하여 COMMD1 유전자의 exon 2 결손 발생 및 그 빈도를 조사하였다. 베들링턴 테리어 257두에서, 정상유전자 동협접합자가 131두(51%), 이형접합자가 108두(42%), 변이유전자 동형접합자가 18두(7%)로 확인되었다. 본 연구를 통해 한국 베들링턴 테리어 개체군의 유전변이 발생 및 그 빈도를 확인하였고, 이는 국내 베들링턴 테리어 개체군의 유전자 선택적 교배계획 설립 및 변이 유전자 확산을 예방하기 위한 기초 자료로서 의의가 있다.

• 한국초등과학교육학회지:초등과학교육
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• 제25권4호
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• pp.352-362
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• 2006

학생들의 개념이 정규 교육 과정에서 배우기 이전의 경험에 의해 선개념이 형성하게 되며 선개념중 오개념들은 과학적 개념을 습득하는 것을 방해한다. 생물학에서 중요한 진화 개념은 특히 오개념이 많은 개념 중 하나이다. 진화에 대한 오개념의 형성 과정에서 TV만화와 아동 과학 도서의 영향이 있을 것으로 판단하여 분석해 보았다. TV 만화의 영향을 확인하기 위하여 TV 만화 속에 등장하는 캐릭터를 활용하여 검사지를 제작하고 초등학생 146명, 중학생 161명, 고등학생 156명에겐 투입하여 분석하고 아동 과학 도서는 16권의 책을 수집하여 진화적 설명이 어떤 형태로 되어 있는지 분석하였다. 연구 결과 아동은 TV 만화 속에서 진화라고 부르는 '성장', '변태' 과정을 진화로 알고 있었다. 그리고 진화의 의미로 '자라면서 변하는 것'의 응답이 매우 높았으며 이는 TV 만화의 영향을 해석된다. 일부 아동 과학 도서에서는 돌연변이, 자연 선택과 같은 개념을 포함시킨 도서도 있었지만 대부분의 아동 과학 도서에서는 진화적 설명으로 목적론적 설명, 내부 의지적 설명, 용불용설적 설명의 형태를 많이 사용하였다. 이는 진화 개념에서 학생들이 많은 오개념을 가지게 된 이유로 TV 만화와 아동 과학 도서 등을 통하여 유입된 잘못된 개념이 원인일 수 있다는 주장을 뒷받침한다. 그리고 TV 만화와 아동 과학 도서에 대한 검정 과정의 필요성을 인식하게 해준다.

• Journal of Veterinary Science
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• 제24권4호
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• pp.51.1-51.17
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• 2023

Background: To date, various genotypes of infectious bronchitis virus (IBV) have co-circulated and in Korea, GI-15 and GI-19 lineages were prevailing. The spike protein, particularly S1 subunit, is responsible for receptor binding, contains hypervariable regions and is also responsible for the emerging of novel variants. Objective: This study aims to investigate the putative major amino acid substitutions for the variants in GI-19. Methods: The S1 sequence data of IBV isolated from 1986 to 2021 in Korea (n = 188) were analyzed. Sequence alignments were carried out using Multiple alignment using Fast Fourier Transform of Geneious prime. The phylogenetic tree was generated using MEGA-11 (ver. 11.0.10) and Bayesian analysis was performed by BEAST v1.10.4. Selective pressure was analyzed via online server Datamonkey. Highlights and visualization of putative critical amino acid were conducted by using PyMol software (version 2.3). Results: Most (93.5%) belonged to the GI-19 lineage in Korea, and the GI-19 lineage was further divided into seven subgroups: KM91-like (Clade A and B), K40/09-like, QX-like (I-IV). Positive selection was identified at nine and six residues in S1 for KM91-like and QX-like IBVs, respectively. In addition, several positive selection sites of S1-NTD were indicated to have mutations at common locations even when new clades were generated. They were all located on the lateral surface of the quaternary structure of the S1 subunits in close proximity to the receptor-binding motif (RBM), putative RBM motif and neutralizing antigenic sites in S1. Conclusions: Our results suggest RBM surrounding sites in the S1 subunit of IBV are highly susceptible to mutation by selective pressure during evolution.

• Molecules and Cells
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• 제39권8호
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• pp.594-602
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• 2016

Alkyl hydroperoxide reductase subunit C from Pseudomonas aeruginosa PAO1 (PaAhpC) is a member of the 2-Cys peroxiredoxin family. Here, we examined the peroxidase and molecular chaperone functions of PaAhpC using a site-directed mutagenesis approach by substitution of Ser and Thr residues with Cys at positions 78 and 105 located between two catalytic cysteines. Substitution of Ser with Cys at position 78 enhanced the chaperone activity of the mutant (S78C-PaAhpC) by approximately 9-fold compared with that of the wild-type protein (WT-PaAhpC). This increased activity may have been associated with the proportionate increase in the high-molecular-weight (HMW) fraction and enhanced hydrophobicity of S78C-PaAhpC. Homology modeling revealed that mutation of $Ser^{78}$ to $Cys^{78}$ resulted in a more compact decameric structure than that observed in WT-PaAhpC and decreased the atomic distance between the two neighboring sulfur atoms of $Cys^{78}$ in the dimer-dimer interface of S78C-PaAhpC, which could be responsible for the enhanced hydrophobic interaction at the dimer-dimer interface. Furthermore, complementation assays showed that S78C-PaAhpC exhibited greatly improved the heat tolerance, resulting in enhanced1 survival under thermal stress. Thus, addition of Cys at position 78 in PaAhpC modulated the functional shifting of this protein from a peroxidase to a chaperone.