• 동양고전연구
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• 제54호
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• pp.155-182
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• 2014

이 논문은 "중용"의 "천명지위성(天命之謂性)"과 "시중(時中)", 그리고 "천지위만물육(天地位萬物育)"의 이슈가 진화생물학의 유전자, 자연선택, 종 다양성 문제와 대화 가능한지 그 가능성을 검토하고 있다. 이를 위해 먼저 성리학과 진화생물학의 유사점과 차이점을 살펴보고, "중용"과 진화생물학의 접점이 무엇인지 모색하고 있다. 이 논문은 세 가지 점에서 "중용"과 진화생물학 사이의 대화 가능성을 검토한다. 첫번째는 인간 본성에 대해 천명지위성과 유전자의 관점에서 대화 가능한지 살펴본다. 두 번째는 존재 이유의 타당성을 시중과 자연선택의 관점에서 살펴본다. 세 번째는 생물간 상호 유연 관계를 천지위만물육과 종 다양성이라는 관점에서 살펴본다. 첫 번째 모색의 소주제들은 <리와 기 vs 유전자와 운반체>의 구조적 연관성, <성선 vs 이기적 유전자의 이타성>의 판단기준, <인 의 예 지 vs 후성규칙>에서 '후천적 선험' 도출 가능성이다. 두 번째 모색의 소주제들은 <천리의 뒤집힘[번(?)] vs 돌연변이>, <변/화 vs 진화>의 시간관, <시중 vs 자연선택/적응>의 메타meta적 접근이다. 세 번째 모색의 소주제들은 <리일분수理一分殊 vs 부분과 전체>의 프랙탈 구조, < 일기一氣 vs 생물간 상호 유연>의 상동관계, <천지위 만물육 vs 생태계>와 치중화致中和의 과제이다. 이러한 모색과 제안들에 대한 후속연구는 "중용"을 둘러싼 성리학 연구의 지평 확대를 가져 올 수 있다.

• 환경생물
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• 제40권4호
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• pp.525-549
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• 2022

개체군은 진화적 단위이자 개체군 통계적 단위로서, 생물학적 침입의 과정은 개체군의 생태적, 진화적 동태에 기인한다. 개체군의 공간구조는 개체군 동태에 영향을 줄 수 있으며, 분산이 반드시 동반되는 생물학적 침입에 대한 연구에서는 공간구조를 고려할 필요가 있다. 메타개체군 이론은 공간구조를 가진 개체군에 대한 대표적인 접근으로, 주로 생태학 및 진화생물학 연구에 활용되고 있다. 메타개체군은 공간적 구조를 가진 개체군의 동의어로 여겨지기도 하지만, 용어의 모호한 사용을 피하기 위해서는 절멸 가능성이 고려되는 경우에 한해 정의되어야 한다는 비판이 있다. 침입 초기 단계의 개체군은 높은 절멸 가능성을 가지는 경우가 많으므로, 메타개체군 이론을 적용하기에 용이하다. 한편, 침입 초기 개체군의 생태적·유전적 특성은 분산의 영향을 크게 받기 때문에, 메타개체군 이론은 개체군 수준에서 침입성의 변화와 침입 가능성을 설명하는 강력한 도구가 될 수 있을 것으로 생각된다. 그러나, 한국에서 침입생물에 대한 생태학적 연구는 주로 종 수준의 분포 변화에 대해 이루어지고 있고, 메타개체군 개념을 적용한 경우가 드문 실정이다. 메타개체군 이론을 활용한다면, 국내 연구가 상대적으로 미진했던 개체군 단위의 침입 기작을 보다 상세히 규명할 수 있을 것으로 생각된다. 본 연구에서는 실제 침입생물에 미치는 메타개체군의 영향을 쉽게 파악하기 위해 침입생물 메타개체군이 자연적인 분산 거리를 넘어서 연결되는지 여부에 따라 장거리와 중거리 두 가지 규모로 나누는 체계를 활용할 것을 제안하였다. 메타개체군 개념에 입각한 침입생물 연구가 침입의 기작을 이해하고 장래의 침입 리스크를 예측·관리하는 데에 도움을 줄 것으로 기대한다.

• Journal of applied mathematics & informatics
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• 제18권1_2호
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• pp.311-320
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• 2005

Studies in the evolutionary biology of aging require good estimates of the age-dependent mortality rate coefficient (one of the Gompertz parameters). In this paper we introduce an alternative algorithm for estimating this parameter. And we discuss the sensitivity of the estimates to changes in the other model parameters.

• Molecules and Cells
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• 제26권3호
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• pp.228-235
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• 2008

Thiol-dependent redox systems are involved in regulation of diverse biological processes, such as response to stress, signal transduction, and protein folding. The thiol-based redox control is provided by mechanistically similar, but structurally distinct families of enzymes known as thiol oxidoreductases. Many such enzymes have been characterized, but identities and functions of the entire sets of thiol oxidoreductases in organisms are not known. Extreme sequence and structural divergence makes identification of these proteins difficult. Thiol oxidoreductases contain a redox-active cysteine residue, or its functional analog selenocysteine, in their active sites. Here, we describe computational methods for in silico prediction of thiol oxidoreductases in nucleotide and protein sequence databases and identification of their redox-active cysteines. We discuss different functional categories of cysteine residues, describe methods for discrimination between catalytic and noncatalytic and between redox and non-redox cysteine residues and highlight unique properties of the redox-active cysteines based on evolutionary conservation, secondary and three-dimensional structures, and sporadic replacement of cysteines with catalytically superior selenocysteine residues.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제9권2호
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• pp.83-89
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• 2005

In this paper a new algorithm of learning and evolving artificial neural networks using gene expression programming (GEP) is presented. Compared with other traditional algorithms, this new algorithm has more advantages in self-learning and self-organizing, and can find optimal solutions of artificial neural networks more efficiently and elegantly. Simulation experiments show that the algorithm of evolving weights or thresholds can easily find the perfect architecture of artificial neural networks, and obviously improves previous traditional evolving methods of artificial neural networks because the GEP algorithm imitates the evolution of the natural neural system of biology according to genotype schemes of biology to crossover and mutate the genes or chromosomes to generate the next generation, and the optimal architecture of artificial neural networks with evolved weights or thresholds is finally achieved.

• Journal of Plant Biotechnology
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• 제44권1호
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• pp.1-11
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• 2017

Evolutionary studies conducted on NAC (NAM, ATAF1&2, and CUC2) genes for all major groups of land plants, indicate the presence of the NAC subfamilies, even in the early land plants. The varied roles played by NAC proteins in plant growth and development range from the formation of shoot apical meristem, floral organ development, reproduction, lateral shoot development, and defense responses to biotic and abiotic stresses. Considering the value and importance of solanaceous crops, the study of NAC proteins in these plants needs to be intensified. This will help to identify and functionally characterize their promoters, which will subsequently aid in engineering plants with improved performance under stressful conditions. In this review, the functionally characterized NAC transcription factors specific to tomato, potato, tobacco, chili pepper and eggplant (aubergine) are summarized, clearly indicating their biological functions in the defense mechanism of the plants, against biotic and abiotic stresses.

• 환경생물
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• 제22권4호
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• pp.479-486
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• 2004

Phytoestrogens display estrogen-like activity because of their structural similarity to human estrogens and exhibit high affinity binding for the estrogen receptors (ERs). The prevalence of phytoestrogens in our diets and the biological effects that they may cause need to be fully examined. ER is the ancestral receptor from which all other steroid receptors have evolved. Although phytoestrogens serve specific signaling functions between the plants and insects, fungi, and bacteria, many chemical signals are often misinterpreted as estrogenic signals in non-target organisms such as vertebrates. There are no ERs in plants or in their most common partners, insects. However, Rhizobium soil bacteria have NodD proteins which is an intended target of phytoestrogen signaling and share genetic homology with the ER. These two evolutionarily distant receptors both recognize and respond to a shared group of chemical signals and ligands, including both agonists and antagonists. This review briefly summarizes estrogen and estrogen receptors, kinds of important phytoestrogens, their health effects as well as some of the evolutionary aspects of mechanism by which phytoestrogen mimics the endogenous ER signaling in our body.

• BMB Reports
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• 제42권6호
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• pp.356-360
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• 2009

In the present study we have examined human-mouse homologous intronless disease and non-disease genes alongside their extent of sequence conservation, tissue expression, domain and gene ontology composition to get an idea regarding evolutionary and functional attributes. We show that selection has significantly discriminated between the two groups and the disease associated genes in particular exhibit lower $K_{a}$ and $K_{a}/K_{s}$ while $K_{s}$ although smaller is not significantly different. Our analyses suggest that majority of disease related intronless human genes have homology limited to eukaryotic genomes and their expression is localized. Also we observed that different classes of intronless disease related genes have experienced diverse selective pressures and are enriched for higher level functionality that is essentially needed for developmental processes in complex organisms. It is expected that these insights will enhance our understanding of the nature of these genes and also improve our ability to identify disease related intronless genes.

• Animal cells and systems
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• 제1권4호
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• pp.619-627
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• 1997

Maintenance of polymorphism in a two-locus system with two alleles under stabilizing selection has been tested by Monte-Carlo simulation. The effect of each allele was additive. Only gene x environment interactions and degree of genetic linkage between loci were considered. There were no other evolutionary forces acting except stabilizing selection. Fixation rates were influenced by the extent of environmental change and the degree of genetic linkage. In most cases, stabilizing selection depleted genetic variability when two loci have a lower degree of linkage (10 cM). When two loci are closely linked (0.1 cM), however, stabilizing selection promoted balanced heterozygotes in changing environments. Thus, environment-dependent selection and recombination rate are important parameters which should be incorporated into mechanisms of maintenance of genetic variability.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제25권4호
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• pp.312-326
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• 2021

The prey-predator model is one of the most influential mathematical models in ecology and evolutionary biology. In this study, we considered a modified prey-predator model, which describes the rate of change for each species. The effects of modifications to the classical prey-predator model are investigated here. The conditions required for the existence of the first integral and the stability of the fixed points are studied. In particular, it is shown that the first integral exists only for a subset of the model parameters, and the phase portraits around the fixed points exhibit physically relevant phenomena over a wide range of the parameter space. The results show that adding coupling terms to the classical model widely expands the dynamics with great potential for applicability in real-world phenomena.