• Title/Summary/Keyword: natural selection

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Shade Matching Identification of in Vivo Natural Teeth and Porcelain-Fused-to-Metal Crowns (자연치와 도재관에 대한 색조선택의 동일성)

  • Cho, Hong-Kyu
    • Journal of Technologic Dentistry
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    • v.29 no.1
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    • pp.35-48
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    • 2007
  • The purpose of this study was to evaluate shade selection using conventional visual assessment in vivo natural teeth and porcelain-fused-to-metal (PFM) crown. Maxillary central incisors, lateral incisors and canines of one hundred twenty four college women were used as vivo natural teeth. Fifty one PFM crown for maxillary central incisor fabricated by dental laboratory were used as experimental materials. Using Vitapan Classical Shade Guides, shade selection of natural teeth was measured by each college woman and shade selection of PFM crown was measured by three ceramists with more than ten years career. Both natural teeth and PFM crown shade selection were measured through Shade Eye-Ex. From the shade selection comparing, following results were obtained. The results were as follows: 1. The shade matching identification of natural teeth between the shade selection using Vitapan Classical Shade Guides and the shade selection using Shade Eye-Ex was 27.4% in maxillary central incisor, 13.7% in lateral incisor and 18.5% in canine. 2. Among the shade selection of PFM crown by three ceramists, the shade evaluation of three ceramists were same only in ten cases. In twenty case, those of two ceramists were same. 3. The shade matching identification of PFM crown between the shade selection using Vitapan Classical Shade Guides and the shade selection using Shade Eye-Ex was 38.6% in average. These results suggest that the shade selection using conventional visual assessment should be dealt with care in clinic and need a credible method for shade matching color.

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Effects of Artificial and Natural Selection on Walking Behavior in Drosophila melanogaster (초파리의 보행행동에 관한 인위도태와 자연도태에 의한 유전적 효과)

  • 주종길;이현화
    • The Korean Journal of Zoology
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    • v.26 no.2
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    • pp.95-106
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    • 1983
  • Selections for rapid and slow walking behavior were carried out with the populations, drived from Oregon-R and lethal free strain of Drosophila melanogaster. The behavior was measured by means of connected test-tube apparatus. The populations responded effectively to the artificial selection, and it reached the selection plateau after 7 generations. The realized heritability for the first 10 generations was estimated to be about $9\\sim14%$ for the rapid walking behavior, and those for slow walking behavior was about $11\\sim16%$. The results of hybridization analysis between selected populations at generations 8 and 10 indicated that some polygenes showing a slow walking behavior were partially dominant over polygenes controlled rapid trait. The populations selected for rapid and slow walking behavior were relaxed after 10 generations of selection. The response to natural selection of rapid population was completely returned to their neutral states after only 5 generations. Such phenomena would be explained by the genetic homeostasis resulted from an action of natural selection. However, the slow population did not make any difference from walking scores of their original artificial selection. It seems reasonable to assume that the slow walking behavior was possibly controlled by a major gene.

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Analyzing Korean Pre-service Biology Teachers' Understanding of the Concept of Natural Selection in Comparison with Chinese, American, and German Biology Majors (중국, 미국, 독일의 생물전공자와 비교한 한국 생물예비교사의 자연선택개념 이해 수준 분석)

  • Ha, Minsu
    • Journal of The Korean Association For Science Education
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    • v.36 no.5
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    • pp.729-737
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    • 2016
  • Natural selection is the core idea of evolution that pre-service biology teachers need to understand to solve diverse biological problem. This study aims to investigate the level of Korean pre-service biology teachers' understanding of natural selection by comparing their knowledge with their Chinese, American, and German biology major undergraduate counterparts. In particular, this study focuses on two conceptual components of natural selection (i.e., ecology and genetics). This study used a total 1226 pre-service biology teachers and biology majors' data. The instrument measuring the understanding of natural selection concepts was Conceptual Inventory of Natural Selection, which consists of ten ecology concept items and ten genetics concept items. The Rasch model analysis, multivariate analysis of variance, and univariate analysis of variance were used for the statistical tests. The result reveals that the level of Korean pre-service biology teachers' understanding of natural selection were similar with Chinese undergraduates' understanding and significantly lower than American and German undergraduates.' In the first year student data, the level of genetics concept of Korean pre-service biology teachers were significantly lower than Chinese and German students. In the fourth year student data, the level of ecology concept of Korean pre-service biology teachers were significantly lower than American and German students. Based on these results, the ecology concept education and balanced natural selection concept education are discussed.

Identification and Characterization of Human Genes Targeted by Natural Selection

  • Ryu, Ha-Jung;Kim, Young-Joo;Park, Young-Kyu;Kim, Jae-Jung;Park, Mi-Young;Seo, Eul-Ju;Yoo, Han-Wook;Park, In-Sook;Oh, Berm-Seok;Lee, Jong-Keuk
    • Genomics & Informatics
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    • v.6 no.4
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    • pp.173-180
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    • 2008
  • The human genome has evolved as a consequence of evolutionary forces, such as natural selection. In this study, we investigated natural selection on the human genes by comparing the numbers of nonsynonymous (NS) and synonymous (S) mutations in individual genes. We initially collected all coding SNP data of all human genes from the public dbSNP. Among the human genes, we selected 3 different selection groups of genes: positively selected genes (NS/S${\geq}$3), negatively selected genes (NS/S${\leq}$1/3) and neutral selection genes (0.9

Natural Selection in Artificial Intelligence: Exploring Consequences and the Imperative for Safety Regulations

  • Seokki Cha
    • Asian Journal of Innovation and Policy
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    • v.12 no.2
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    • pp.261-267
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    • 2023
  • In the paper of 'Natural Selection Favors AIs over Humans,' Dan Hendrycks applies principles of Darwinian evolution to forecast potential trajectories of AI development. He proposes that competitive pressures within corporate and military realms could lead to AI replacing human roles and exhibiting self-interested behaviors. However, such claims carry the risk of oversimplifying the complex issues of competition and natural selection without clear criteria for judging whether AI is selfish or altruistic, necessitating a more in-depth analysis and critique. Other studies, such as ''The Threat of AI and Our Response: The AI Charter of Ethics in South Korea,' offer diverse opinions on the natural selection of artificial intelligence, examining major threats that may arise from AI, including AI's value judgment and malicious use, and emphasizing the need for immediate discussions on social solutions. Such contemplation is not merely a technical issue but also significant from an ethical standpoint, requiring thoughtful consideration of how the development of AI harmonizes with human welfare and values. It is also essential to emphasize the importance of cooperation between artificial intelligence and humans. Hendrycks's work, while speculative, is supported by historical observations of inevitable evolution given the right conditions, and it prompts deep contemplation of these issues, setting the stage for future research focused on AI safety, regulation, and ethical considerations.

Introduction to a Novel Optimization Method : Artificial Immune Systems (새로운 최적화 기법 소개 : 인공면역시스템)

  • Yang, Byung-Hak
    • IE interfaces
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    • v.20 no.4
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    • pp.458-468
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    • 2007
  • Artificial immune systems (AIS) are one of natural computing inspired by the natural immune system. The fault detection, the pattern recognition, the system control and the optimization are major application area of artificial immune systems. This paper gives a concept of artificial immune systems and useful techniques as like the clonal selection, the immune network theory and the negative selection. A concise survey on the optimization problem based on artificial immune systems is generated. The overall performance of artificial immune systems for the optimization problem is discussed.

Identifying Copy Number Variants under Selection in Geographically Structured Populations Based on F-statistics

  • Song, Hae-Hiang;Hu, Hae-Jin;Seok, In-Hae;Chung, Yeun-Jun
    • Genomics & Informatics
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    • v.10 no.2
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    • pp.81-87
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    • 2012
  • Large-scale copy number variants (CNVs) in the human provide the raw material for delineating population differences, as natural selection may have affected at least some of the CNVs thus far discovered. Although the examination of relatively large numbers of specific ethnic groups has recently started in regard to inter-ethnic group differences in CNVs, identifying and understanding particular instances of natural selection have not been performed. The traditional $F_{ST}$ measure, obtained from differences in allele frequencies between populations, has been used to identify CNVs loci subject to geographically varying selection. Here, we review advances and the application of multinomial-Dirichlet likelihood methods of inference for identifying genome regions that have been subject to natural selection with the $F_{ST}$ estimates. The contents of presentation are not new; however, this review clarifies how the application of the methods to CNV data, which remains largely unexplored, is possible. A hierarchical Bayesian method, which is implemented via Markov Chain Monte Carlo, estimates locus-specific $F_{ST}$ and can identify outlying CNVs loci with large values of FST. By applying this Bayesian method to the publicly available CNV data, we identified the CNV loci that show signals of natural selection, which may elucidate the genetic basis of human disease and diversity.

The Prediction of the Expected Current Selection Coefficient of Single Nucleotide Polymorphism Associated with Holstein Milk Yield, Fat and Protein Contents

  • Lee, Young-Sup;Shin, Donghyun;Lee, Wonseok;Taye, Mengistie;Cho, Kwanghyun;Park, Kyoung-Do;Kim, Heebal
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.1
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    • pp.36-42
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    • 2016
  • Milk-related traits (milk yield, fat and protein) have been crucial to selection of Holstein. It is essential to find the current selection trends of Holstein. Despite this, uncovering the current trends of selection have been ignored in previous studies. We suggest a new formula to detect the current selection trends based on single nucleotide polymorphisms (SNP). This suggestion is based on the best linear unbiased prediction (BLUP) and the Fisher's fundamental theorem of natural selection both of which are trait-dependent. Fisher's theorem links the additive genetic variance to the selection coefficient. For Holstein milk production traits, we estimated the additive genetic variance using SNP effect from BLUP and selection coefficients based on genetic variance to search highly selective SNPs. Through these processes, we identified significantly selective SNPs. The number of genes containing highly selective SNPs with p-value <0.01 (nearly top 1% SNPs) in all traits and p-value <0.001 (nearly top 0.1%) in any traits was 14. They are phosphodiesterase 4B (PDE4B), serine/threonine kinase 40 (STK40), collagen, type XI, alpha 1 (COL11A1), ephrin-A1 (EFNA1), netrin 4 (NTN4), neuron specific gene family member 1 (NSG1), estrogen receptor 1 (ESR1), neurexin 3 (NRXN3), spectrin, beta, non-erythrocytic 1 (SPTBN1), ADP-ribosylation factor interacting protein 1 (ARFIP1), mutL homolog 1 (MLH1), transmembrane channel-like 7 (TMC7), carboxypeptidase X, member 2 (CPXM2) and ADAM metallopeptidase domain 12 (ADAM12). These genes may be important for future artificial selection trends. Also, we found that the SNP effect predicted from BLUP was the key factor to determine the expected current selection coefficient of SNP. Under Hardy-Weinberg equilibrium of SNP markers in current generation, the selection coefficient is equivalent to $2^*SNP$ effect.

Artificial and Natural Selection for Phototactic Behavior in Drosophila melanogaster (초파리의 走光性行動에 대한 人爲淘汰와 自然淘汰)

  • Choo, Jong-Kil
    • The Korean Journal of Zoology
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    • v.20 no.1
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    • pp.1-8
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    • 1977
  • Several hundred flies of Drosophila melanogaster collected in Anyang City were selected for positive, negative and neutral directions during 15 generations. The population responded effectively to the artificial selection. The realized heritability estimated for the first 10 generations was $2 \\sim 4%$ per generation in the positive and negative phototaxis. The results of diallel crosses among selected populations indicated that some polygenes showing a negative phototaxis were partially dominant over polygenes controlled the positive phototaxis, and the dominant effect became greater in later generations. The populations selected for positive and negative phototaxis were relaxed after 15 generations of selection, and their phototactic responses were completely returned to their original states. Such phenomena would be explained by the genetic homeostasis resulted from an action of natural selection. It seems reasonable to assume that the phototactic neutrality of a natural population was maintained as an adaptive trait under natural environment.

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A STUDY ON THE SELECTION OF ARTIFICIAL TEETH FOR THE EDENTULOUS PATIENTS IN KOREANS (한국인 무치악환자의 인공치아선택방법에 관한 연구)

  • Kim, Sung-Hun;Shin, Sang-Wan
    • The Journal of Korean Academy of Prosthodontics
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    • v.34 no.3
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    • pp.457-463
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    • 1996
  • An esthetically pleasing result in denture service is dependent upon several consideration. Esthetic considerations for the edentulous patient include tooth size, shape, arrangement, positioning, gingival contour, age, sex, personality differences, and ethnic type. Especially, the form of anterior artificial teeth is an important factor on the esthetics. The selection of artificaial teeth requires understanding and knowledge on physical and biologic factors and has to meet the indivisul esthetics and functional needs of each patient. However, the selection of artificial teeth is based on the large degree of subjective judgement of the dentist, Therefore, this is one of the most unscientific processes. Many attempts have been made to find a guideline for the selection of artificial teeth. Temperamental theory by White and Hall utillized with the physical characteristics such as body size, body form, color of eyes and hair, and disposition. SPA theory by Frush and Fisher utilized with the basis of sex, personalities, and age of the indivisual. There has not been provided for a guideline and study on the selection of artificial teeth for Koreans yet. This study was aimed to evaluate the William's typal matching theory in Koreans. 1. The facial forms of korean adult were ovoid(46.3%), square(36.7%) and tapered(17.0%) form. 2. The anatomic forms of natural maxillary incisors were ovoid(45.3%), tapered(31.3%), square(23.3%) form. 3. The forms of face and natural maxillary incisors were ovoid(21.9%), squared(11%), tapered(6.3%). 4. The natural maxillary incisors were similar in form to the facial form only in 39%. There was no correlation between the form of the face and the form of natural maxillary central inisors in Koreans. 5. Artificaial teeth which was selected according to the typal matching theory did not represent the form of the natural teeth in 61 per cents of the fatal, but it felt that they harmonized with the form of the patient's face and produced good results.

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