• Title/Summary/Keyword: human evolution

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A Cross-Sectional Study of Students' Conceptions on Evolution and Characteristics of Concept Formation about It in Terms of the Subjects: Human, Animals and Plants (설명대상에 따른 학생들의 진화 개념과 진화 개념 형성의 특성에 관한 횡단 연구)

  • Ha, Min-Su;Lee, Jun-Ki;Cha, Hee-Young
    • Journal of The Korean Association For Science Education
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    • v.26 no.7
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    • pp.813-825
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    • 2006
  • The purpose of this study was to identify students' conceptions and their conceptualization traits in terms of the explanation of subjects: human, animals, and plants. A questionnaire was specially developed to make sure students' conceptions of evolution, students' explanation patterns with the five evolutionary explanations: creationism, internal will explanation, theological explanations, use and disuse explanation and natural selection after mutation and perceived ideas of evolution in terms of the genetic characters of human, animals and plants. 1,540 elementary, middle and high school students participated in responding to the questions. The data was collected and analyzed cross-sectionally by age. Results showed that students' evolutionary explanations were different among each subject: human, animals and plants. Students had concentrated with more 'theological explanations' than 'internal will explanation' and 'use and disuse explanation' about plant evolution. 'Natural selection after mutation explanation' was less represented in explaining human characters. This result showed that the anthropocentric thoughts had influenced students' evolution conceptions. Accordingly, as student's age, 'theological explanation' and 'internal will explanation' became least used in explaining the theory of creation. 'Use and disuse explanation' attained more representation in their explanation. In addition, the diversity of students' evolutionary explanations was getting less attention as age increases. Among youngers, 'theological explanation', 'internal will explanation' and 'use and disuse explanation' showed an even number of responses. The elders responded with more 'use and disuse explanation'. This result let us infer that 'use and disuse explanation' was strongly adhered to by student cognitive structures. Many students recognized that evolution was a kind of scientific hypothesis with little evidence. They have had a little interest in evolution and conceptualized it through informal educational sources. This study mentions that to teach evolution more effectively, teachers should make 'use and disuse explanation' adhere strongly to students' cognitive structure.

Comparative Genomics of T-complex protein 10 like in Humans and Chimpanzees

  • Kim, Il-Chul;Kim, Dae-Soo;Kim, Dae-Won;Choi, Sang-Haeng;Choi, Han-Ho;Chae, Sung-Hwa;Park, Hong-Seog
    • Genomics & Informatics
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    • v.3 no.2
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    • pp.61-65
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    • 2005
  • Comparing 231 genes on chimpanzee chromosome 22 with their orthologous on human chromosome 21, we have found that 15 orthologs have indels within their coding sequences. It was rather surprising that significant number of genes have changed by indel, despite the shorter time since their divergence and led us hypothesize that indels and structural changes may represent one of the major mechanism of proteome evolution in the higher primates. Human T-complex protein 10 like (TCP 10L) is a representative having indel within its coding sequence. Gene structure of human TCP10L compared with chimpanzee TCP10L gene showed 16 base pair difference in genomic DNA. As a result of the indel, frame shift mutation occurs in coding sequence (CDS) and human TCP10L express longer polypeptide of 21 amino acid residues than that of chimpanzee. Our prediction found that the indel may affect to dramatic change of secondary protein structure between human and chimpanzee TCP10L. Especially, the structural changes in the C-terminal region of TCP10L protein may affect on the interacting potential to other proteins rather than DNA binding function of the protein. Through these changes, TCP10L might influence gene expression profiles in liver and testis and subsequently influence the physiological changes required in primate evolution.

The Liquid and Viral Barrier Properties of Reusable and Disposable Surgical Gowns (수술가운의 방수성과 방균성에 관한 연구)

  • Song, Min Kyu;McCullough, Elizabeth A.
    • Journal of the Korean Society of Clothing and Textiles
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    • v.17 no.1
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    • pp.37-47
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    • 1993
  • 최근에 치명적인 바이러스, 특히 에이즈를 이르키는 Human Immunodificiency Virus (HIV), 또는 간에 심각한 병을 이르키는 Hepatitis B Virus (HBV)와 같은 무서운 바이러스가 환자의 피나 분비물을 통하여 의사에게 전염되는 사례가 늘어감에 따라 이제는 환자의 피나 분비물의 침투를 막기 위해 방수성과 방균성을 가진 수술복 착용이 절대적으로 필요하게 되었다. 따라서 본 연구의 목적은 1. 수술가운을 만드는 5가지 대표적인 직물의 방수성과 방균성을 측정하고 2. 세탁시 표백제의 사용유무가 그 직물의 방수성과 방균성에 미치는 영향을 알아보고 3. 반복세탁이 그 직물의 방수성과 방균성에 미치는 영향을 알아 보는데 있다. 이 실험을 위해 3가지 재사용 수술가운과 (Gore-tex$^R$, membrane reinforced; Compel$^{TM}$, fabric reinforced; Acep$^{TM}$, non-reinforced) 두 가지 일회용 가운 (Evolution$^R$ gown, fabric reinforced; Evolution$^R$ Specialty, film reinforced)이 사용되었다. 표백제를 사용한 세탁이 직물의 방수성과 방균성에 미치는 영향을 알아보기 위해 재사용 가운을 세탁, 건조, 살균을 하였다. 세탁과 살균의 빈도수는 1, 20, 40, 50, 60, 70, 80번 이였다. 방수성 측정방법으로 1. Impact Penetration test (AATCC 42-1985), 2. Elbow Lean test, 3. Synthetic Blood Resistance test (ASTM F 23. 40. 01)가 사용되었고 방균성 측정방법으로 Viral Resistance test (ASTM F 23. 40. 02)가 사용되었다. 실험 결과는 다음과 같다. 1. Gore-Tex$^R$ 가운과 Evolution$^R$ Specialty 가운은 방수성과 방균성의 성질을 가졌다. 그러나 표백제를 사용하여 70번 세탁한 Gore-Tex$^R$ 가운은 membrane의 구조가 파괴되어서 방균성을 상실했다. 2. Evolution$^R$ 가운, Acep$^{TM}$ 가운과 Compel$^{TM}$ 가운은 오직 Impact Penetration test만 통과했다. 즉 이 직물들은 큰 압력의 가함이 없는 splash resistance만 가지고있다. 그러나 Acep$^{TM}$ 가운과 Compel$^{TM}$ 가운은 20번과 60번 세탁 후 각각 그들의 splash resistance 마져도 상실했다.

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Distinct Repressive Properties of the Mammalian and Fish Orphan Nuclear Receptors SHP and DAX-1

  • Park, Yun-Yong;Teyssier, Catherine;Vanacker, Jean-Marc;Choi, Hueng-Sik
    • Molecules and Cells
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    • v.23 no.3
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    • pp.331-339
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    • 2007
  • It has been suggested that the structure and function of nuclear receptors are evolutionally conserved. Here, we compare the molecular functions of the nile tilapia (Oreochromis niloticus) small heterodimer partner (nSHP/NR0B2) and the Dosage-sensitive sex reversal AHC critical region on X chromosome gene 1 (nDAX-1/NR0B1) with those of human SHP and DAX-1 (hSHP and hDAX-1, respectively). We found that, upon transient cotransfection of human cells, nDAX-1 repressed the activity of tilapia SF-1 (nSF-1) but not that of human SF-1, although the physical interaction with human SF-1 was retained. Similarly, nSHP repressed the activity of nSF-1, whereas hSHP did not, pointing to divergent evolution of SHP/SF-1 in fish and human. We thus propose that the repressive functions of SHP and DAX-1 have been conserved in fish and mammals although with different transcriptional targets and mechanisms. These differences provide new insights into the physiological diversification of atypical orphan nuclear receptors during vertebrate evolution.

Post-Humans in the SF Narrative and Their Potential as the New Subject (SF서사에서 나타나는 포스트휴먼과 새로운 주체로서의 가능성)

  • Choo, Hye-Jin
    • The Journal of the Korea Contents Association
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    • v.20 no.12
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    • pp.95-102
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    • 2020
  • The purpose of this study is to seek a new understanding of human beings by examining, through the various types of futuristic humans in SF narratives, the changes of human condition and identity, raised by the discussion on the posthuman today. The rapid development of science and technology blurs the line between humans and machines, predicting the birth of the 'new human posterior to the human'. The advancement of technology enables the production of 'human beyond the biological human' through the combination of humans and machines, and humans are becoming more mechanized. On the other hand, machines are gradually developing to the stage of resembling not just the exterior body structure, but the thinking abilities and emotions of human beings. However, by colliding with the traditional view of human beings, artificial changes to the human condition as a result of cutting-edge technology demand a new perspective on the meaning of a new being and changes in human conditions. Therefore, the study examines how human conditions and perceptions have changed in accordance with the evolution of science and technology, and then explores the direction of co-evolution between humans and machines through the various types of futuristic humans that appear in the SF narratives, as well as the potential of futuristic humans as the new subject.

Directed Evolution of Soluble α-1,2-Fucosyltransferase Using Kanamycin Resistance Protein as a Phenotypic Reporter for Efficient Production of 2'-Fucosyllactose

  • Jonghyeok Shin;Seungjoo Kim;Wonbeom Park;Kyoung Chan Jin;Sun-Ki Kim;Dae-Hyuk Kweon
    • Journal of Microbiology and Biotechnology
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    • v.32 no.11
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    • pp.1471-1478
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    • 2022
  • 2'-Fucosyllactose (2'-FL), the most abundant fucosylated oligosaccharide in human milk, has multiple beneficial effects on human health. However, its biosynthesis by metabolically engineered Escherichia coli is often hampered owing to the insolubility and instability of α-1,2-fucosyltransferase (the rate-limiting enzyme). In this study, we aimed to enhance 2'-FL production by increasing the expression of soluble α-1,2-fucosyltransferase from Helicobacter pylori (FucT2). Because structural information regarding FucT2 has not been unveiled, we decided to improve the expression of soluble FucT2 in E. coli via directed evolution using a protein solubility biosensor that links protein solubility to antimicrobial resistance. For such a system to be viable, the activity of kanamycin resistance protein (KanR) should be dependent on FucT2 solubility. KanR was fused to the C-terminus of mutant libraries of FucT2, which were generated using a combination of error-prone PCR and DNA shuffling. Notably, one round of the directed evolution process, which consisted of mutant library generation and selection based on kanamycin resistance, resulted in a significant increase in the expression level of soluble FucT2. As a result, a batch fermentation with the ΔL M15 pBCGW strain, expressing the FucT2 mutant (F#1-5) isolated from the first round of the directed evolution process, resulted in the production of 0.31 g/l 2'-FL with a yield of 0.22 g 2'-FL/g lactose, showing 1.72- and 1.51-fold increase in the titer and yield, respectively, compared to those of the control strain. The simple and powerful method developed in this study could be applied to enhance the solubility of other unstable enzymes.

MitGEN: Single Nucleotide Polymorphism DB Browser for Human Mitochondrial Genome

  • Park, Hyun Seok;Lee, Seung Uk
    • Genomics & Informatics
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    • v.2 no.3
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    • pp.147-148
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    • 2004
  • Recently completed mitochondrial genome databses from public resources provide us with a better understanding of individual mitochondrial genomes for population genomics. By determining the substitution rate of the genomic sequences, it is plausible to derive dates on the phylogenetic tree and build a chronology of events in the evolution of human species. MitGEN is specially designed as a mitochondrial genome browser for analyzing, comparing and visualizing single nucleotide polymorphism for human mitochondrial genomes between human races for comparative genomics. It is a standalone application and is available free for non-commercial work.

Human Y Chromosome: Structure, Function and Evolution (인간 Y 염색체: 구조, 기능 그리고 진화)

  • 홍경원;허재원;김희수
    • Journal of Life Science
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    • v.13 no.6
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    • pp.958-969
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    • 2003
  • The human Y chromosome is strictly paternally inherited and does not X-Y crossing over during male meiosis in most of its length. Although this region came to be known as the non-recombining region Y (NRY), it was renamed as male-specific region Y (MSY) due to abundant recombination. The MSY is a mosaic of heterochromatic sequences and three classes of euchromatic sequences: X-transposed, X-degenerated and ampliconic. The X-transposed sequences exhibit 99% identity to the X chromosomal sequences. The X-degenerate sequences are remnants of ancient autosomes from which the modem X and Y chromosomes evolved. Eight palindromes of the ampliconic comprise one-quarter of the euchromatic DNA of the male-specific region of the human Y chromosome. They contain many testis-specific genes and typically exhibit 99.97% intra-palindromic (arm-to-arm) sequence identity. The arms of these palindromes must have subsequently engaged in gene conversion, driving the pair arms to evolve it concert. Averages of approximately 600 nucleotides per newborn male have undergone Y-Y gene conversion, which has had an important role in the evolution of multi-copy testis gene families in the MSY.

A Comparison between Korean and American College Students' Evolution Concepts based on the History of Evolutionary Ideas (진화개념의 역사에 근거한 한국과 미국 대학생의 진화개념 수준 비교)

  • Ha, Minsu
    • Journal of The Korean Association For Science Education
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    • v.37 no.4
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    • pp.659-668
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    • 2017
  • This study was conducted to identify whether there is a significant difference in the developmental stages of the evolution concept depending on the major and the country. For this study, college students (both biology major and non-biology major) in Korea and the United States answered evolution concept assessment developed by Ha (2007). The data were analyzed based on the method of developed by Ha (2016). As a result of this study, Cronbach alpha for internal consistency reliability and MNSQ indices for item response fitness of the ordered multiple choice method providing 0 to 4 point scores to creationism, teleology, intentionality, use/disuse, and natural selection respectively, satisfied the benchmark. The level of Korean college students' evolution concepts was located in use/disuse and the level of USA college students' evolution concepts was located in teleology. No interaction effect was found between the difference of conceptual progressions of evolution concept by major and country and evolution contexts (human, animal, and plant). There was a significant relationship between developmental stages of evolution concept and their religiosity. Based on the results of this study, we discuss developmental characteristics of evolutionary concepts.