Comprehensive genomic analyses with 115 plastomes from algae to seed plants: structure, gene contents, GC contents, and introns

Eun‑Chae Kwon,Jong‑Hwa Kim,Nam‑Soo Kim 한국유전학회 2020 Genes & Genomics Vol.42 No.5

Background Chloroplasts are a common character in plants. The chloroplasts in each plant lineage have shaped their own genomes, plastomes, by structural changes and transferring many genes to nuclear genomes during plant evolution. Some plastid genes have introns that are mostly group II introns. Objective This study aimed to get genomic and evolutionary insights on the plastomes from green algae to flowering plants. Methods Plastomes of 115 species from green algae, bryophytes, pteridophytes (spore bearing vascular plants), gymnosperms, and angiosperms were mined from NCBI organelle genome database. Plastome structure, gene contents and GC contents were analyzed by the in-house developed Phyton code. Intronic features including presence/absence, length, intron phases were analyzed by manually in the annotated information in NCBI. Results The canonical quadripartite structures were retained in most plastomes except of a few plastomes that had lost an invert repeat (IR). Expansion or reduction or deletion of IRs resulted in the length variation of the plastomes. The number of protein coding genes ranged from 40 to 92 with an average 79.43 ± 5.84 per plastome and gene losses were apparent in specific lineages. The number of trn genes ranged from 13 to 33 with an average 21.19 ± 2.42 per plastome. Ribosomal RNA genes, rrn, were located in the IRs so that they were present in a duplicate except of the species that had lost one of the IR. GC contents were variable from 24.9 to 51.0% with an average 38.21 ± 3.27%, indicating bias to high AT contents. Plastid introns were present in 18 protein coding genes, six trn genes, and one rrn gene. Intron losses occurred among the orthologous genes in different plant lineages. The plastid introns were long compared with the nuclear introns, which might be related with the spliceosome nuclear introns and self-splicing group II plastid introns. The trnK-UUU intron contained the maturase encoding matK gene except in the chlorophyte algae and monilophyte ferns in which the trnK-UUU was lost, but matK retained. There were many annotation artefacts in the intron positions in the NCBI database. In the analysis of intron phases, phase 0 introns were more frequent than those of phase 2 and 3 introns. Phase polymorphism was observed in the introns of clpP which was derived from nucleotide insertion. Plastid trn introns were long compared to the archaeal or eukaryotic nuclear tRNA introns. Of the six plastid trn introns, one was at the D loop and other five were at the anticodon loop. The insertion sites were conserved among the trn genes in archaea, eukaryotic nuclear and plastid tRNA genes. Conclusions Current study refurbrished the previous findings of structural variations, gene contents, and GC contents of the chloroplast genomes from green algae to flowering plants. The study also included some noble findings and discussions on the plastome introns including their length variations and phase variation. We also presented and corrected some false annotations on the introns in protein coding and tRNA genes in the genome database, which might be confirmed by the chloroplast transcriptome analysis in the future.

동맥내막절제술과 동맥내 스텐트 삽입술을 이용한 청색지증후군 치험 2예 : 2 Cases Report

권정남,박동은,채권묵,노병석,소병준 대한혈관외과학회 2003 Vascular Specialist International Vol.19 No.1

인지갈등 상황 제시유형에 따른 고등학생들의 역학 개념 변화

이채은,이경호,김지나,권재술 한국교원대학교 과학교육연구소 2001 청람과학교육연구논총 Vol.11 No.1

학생들의 개념 변화를 촉진하기 위하여 인지갈등상황을 제시하는 것이 필요하다는 주장이 여러 연구자들에 의하여 제기 되어왔다. 본 연구자들은 문헌 분석을 통하여 인지갈등을 유발할 수 있는 상황은 크게 세가지로 구분할 수 있었다. 이 연구의 목적은 이들 세가지 상황이 학생들의 과학개념 변화에 미치는 영향의 차이를 알아보는 것이었다. 연구 대상으로 참여한 학생은 경기도 소재의 인문 고등학교 2학년 72명이다. 갈등상황으로 체험을 제시할 때 직접 실험할 수 있는 인원의 한계성 때문에 한 반에 26명씩 선정하였다. 먼저 역학의 중요 개념에 대한 여섯 가지 문항을 이용하여 학생들의 사전 개념을 조사한 후, 갈등상황을 현상, 논리, 체험 등 3가지로 나누어 제시하고 수업을 한 다음 사후 검사를 실시하였다. 개념 변화의 지속성을 보기 위해서 1주일 후와 1개월 후에 같은 문항으로 검사를 실시하였다. 이 검사 결과를 바탕으로 각 문항별 응답 유형을 분석하여 학생들의 개념이 과학적으로 변화하였는지 조사하였다. 연구결과, 각 문항에서 과학적 개념으로 변화하는 학생 수는 체험 제시 집단이 다른 두 집단에 비하여 많았으며 그 다음은 현상제시 집단이었다. 제시 특성별로 보면, 근운동을 통한 강한 체험이 가능한 문항에서는 체험제시의 효과가 높게 나타났으며 다른 문항들에서도 체험이나 시각적으로 명확하게 관찰이 가능한 정도에 따라 논리제시에 비하여 체험제시와 현상제시가 개념 변화에 효과적인 것으로 나타났다. 따라서 학생들의 과학개념 변화를 위해서는 개념 특성에 맞는 적절한 갈등상황을 제시해야 한다고 본다. 또한, 효과적인 개념 변화를 위해 갈등상황을 제시할 때, 모든 문항에 대해 현상이나 논리, 체험제시 중 어느 하나가 더 효과적이라고 구별하기보다는 문항의 종류와 갈등상황 제시의 특성, 학습자의 상태 등을 고려하여 제시해야 한다고 본다. Researchers on conceptual change have been proposed that confronting a cognitive conflict situation would be important for a student to change his/her preexisting conception. There have been reported that there are three different methods of producing a cognitive conflict situation; the first is logical argument(LC), the second is demonstration of an actual phenomenon(DC), and the third is kinesthetic conflict which is a kind of physical experience(EC). In this study, the researcher tried to find out the differences in the conceptual changes by the three different conflict situations. Seventy two high school students were chosen in a high school in Kyungkido, Korea. The students were tested four times; pretest, posttest, one week delayed posttest, and one month delayed posttest. Six different test situations on mechanics were developed for this study. Test item for each situation was developed. Each item consisted of a multiple choice question and explanation of the choice. The result showed a clear differences among the three conflict groups. In general, kinesthetic conflict which is a kind of physical experience(EC) was proved to be the most efficient strategy for the conceptual change; however, logical argument(LC) seemed to be the least efficient. However, the effectiveness was not uniform from situation to situation. Results of some items showed that even the LC was quite good for the conceptual change. Therefore, it seems to be important to develope appropriate method for the target concept.

인장물성 평가를 위한 연속압입시험법의 실험조건 최적화

전은채,박주승,권동일 대한금속재료학회 2002 대한금속·재료학회지 Vol.41 No.2

The continuous indentation test, which measures indentation depth with applied load, has been used to evaluate the tensile properties whose accuracy can vary depending on such experimental conditions as maximum depth ratio, indenter radius, number of unloadings and unloading ratio. In this study, Taguchi method, one of the designs of experiment, was applied to quantify the effects of the experimental conditions effectively. Using a signal-to-noise ratio calculated from the error in the indentation tensile properties, the optimum values of the experimental conditions were presented. The indentation tensile properties from the load-depth curves with the optimum conditions showed better accuracy than those with existing conditions.

압입유동특성 평가를 위한 진변형률 정의에 관한 고찰

전은채,백민경,김성훈,박주승,권동일 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.12

Continuous indentation test is getting more used to derive indentation flow curve. The overall deriving algorithm is relatively well-established, the details of the algorithm are, however, still argued. One of the arguments is the definition of true strain which constitutes the indentation flow curve. In this study, work-hardening exponent was adopted for determining what definition is appropriate to obtain accurate indentation flow curve since work-hardening exponent is affected by only the definition of true strain not by other constants. The effect of calibrating contact depth was eliminated using finite element analysis. Finally, the definition based on tangent function was determined to be proper for deriving the indentation flow curve. (Received September 8, 2004)

중학교 화학 분야의 개념 연구에 대한 문제점 분석

朴恩姬,姜대勳,白盛惠,朴國泰,金惠敬,蔡禹기,權鈞 한국교원대학교 과학교육연구소 1999 청람과학교육연구논총 Vol.9 No.1

중학교 화학 분야의 오개념 조사에 사용된 설문지의 문제점을 밝혀, 학생들의 정확한 오개념 조사를 위한 바탕을 마련하고자 한다. 기존의 중학교 화학 분야에 대한 오개념 조사 설문지가 연구 대상 학생들에게 잘못 사용되고 있었으며, 문항 내용 자체에도 오류가 있었음을 지적하고자 하는 것이다. 선행 연구들의 분석 결과들이 오개념이 아니라 무개념임을 확인하기 위하여 중학교 1학년 학생 182명을 대상으로 두 종류의 설문지 A와 B를 투입하여 조사하였다. 설문지 A는 오개념 연구를 위해 선행 연구들에서 사용한 문항들로 이루어진 것으로, 이를 투입한 결과를 선행 연구들의 결과들과 비교하기 위한 것이다. 그리고 설문지 B는 설문지 A에서 응답한 학생들의 구체적인 생각을 알아보기 위하여 새롭게 개발한 것이다. 설문지 A를 통해 얻은 결과와 선행 연구들에서 얻은 결과들을 비교할 때, 전반적으로 일관성이 없게 나타났으며, 중학교 1학년 학생들의 주관식 정답률이 객관식 정답률에 비해 매우 낮게 나타나는 공통점은 있었으나, 문항 자체의 오류들이 발견되었다. 설문지 B를 통해 학생들의 생각을 알아본 결과, 설문지 A에서 과학적 개념과 오개념으로 분류된 학생들 중에서 무개념으로 판단된 경우가 많았다. This study was to clarify the problems of questionnaires related to misconception researches of middle school chemistry and to prepare a ground for the correct misconception research for students. For these purposes, the questionnaires of the misconception researches related to chemistry in middle school were analyzed, and the mistakes of the questions which were used in 7th grade students were found, based on a definition of misconceptions in this study. Also, the errors in contents of the questionnaires were indicated. The results of the analysis revealed that most of the 7th grade students did not have misconceptions contrary to some of the previous researches conclusions. They only had no conceptions related to the contents. In order to support this analysis, two different questionnaire sets (questionnaire set A and B) for 182 7th grade students were used. After obtaining similar results to those of the previous researches by the questionnaire set A, the students' thoughts were examined by the questionnaire set B. From the results of this study, the correct answer rates of subjective questions were very low compared with those of objective questions in the questionnaire set A for 7th grade students. It was hard to find consistency among the results of the researches using the questionnaire set A. And many contents of the questions consisted of the questionnaire set A were not consisted with a definition of misconceptions. There were errors in the contents of the questions, too. The students classified as the having-science-concepts group and the having-misconceptions group by the questionnaire set A were classified as the having-no-concepts group by the questionnaire set B.

압입하중-변위곡선의 정량적 해석을 통한 가공경화지수의 평가

全銀埰,安政勳,權東一 대한금속재료학회 2001 대한금속·재료학회지 Vol.39 No.12

Continuous indentation test with ball indenter has been studied for years because of its convenience and simpleness. Especially, the test is expected to supersede tensile test. Among tensile properties work-hardening exponents of various steels were evaluated by the test. We newly defined true stress and true strain with contact depth and indentation load. Finite element analysis shows that the contact depth is affected by elastic deflection and pile-up/sink-in. Therefore, the contact depth was calculated with taken both elastic deflection and pile-up/sink-in into account. The work-hardening exponents derived in this study show good agreement to those from tensile test.

성인 IgA 신병증의 임상적 고찰

김영학,권용은,허경무,윤채중,김종인,김건영,배학연,정종훈 조선의대 1998 The Medical Journal of Chosun University Vol.23 No.1

Characterization of Molecular and Enzymatic Properties of Three Cholinesterases from Cimex lectularius

Chae Eun Hwang,Keon Mook Seong,Deok Ho Kwon,Young Ho Kim,Jae Young Choi,Yeon Ho Je,Si Hyeock Lee 한국응용곤충학회 2012 한국응용곤충학회 학술대회논문집 Vol.2012 No.05

We analyzed molecular and enzymatic properties of three cholinesterases (ChEs; ClAChE1, ClAChE2 and ClSChE) from Cimex lectularius. The ClAChE1 and ClAChE2 were generally present as a membrane-anchored dimeric insoluble form in the brain and ganglia. In the case of ClSChE, monomeric and dimeric soluble forms were observed. To investigate enzymatic properties, three ChEs were functionally expressed using baculovirus expression system. ClAChE1 revealed a significantly higher activity than ClAChE2 to acetylthiocholine iodide (ATChI) substrate. Kinetic analysis using two choline substrates (ATChI and butyrylthiocholine iodide) demonstrated that ClAChE2 had higher catalytic efficiency but lower substrate specificity than ClAChE1. Inhibition assay was conducted by using three inhibitors (BW284C51, eserine, Iso-OMPA) and two insecticides (chlorpyrifos-methyl and carbaryl). Two ClAChEs revealed high sensitivities to BW284C51, eserine, chlorpyrifos-methyl and carbaryl, but were not sensitive to Iso-OMPA. This inhibition profile confirmed that both ClAChEs are categorized as ChEs. Interestingly, the salivary specific cholinesterase did not show any measurable activities to choline substrates, confirming its non-synaptic function in C. lectularius

친환경 요소를 표현한 영남대 국제교류센터 리모델링

권은채(Kwon, Eun-Chae),이종민(Lee, Jong-Min) 한국실내디자인학회 2018 한국실내디자인학회 학술대회논문집 Vol.20 No.3

In March 2018, the 4th grade building design studio (5), which is the first semester of the 4th grade, conducted a project to revitalize the international exchange center located in Youngnam University through eco-friendly construction. In line with European countries that are leading global environmental policy, fine dust has raised the issue of the environment recently, resulting in a gradual shift in perception and increasing interest among Koreans and government. Various alternatives are being sought to cope with this, and existing architectures that are directly linked to the destruction of ecosystem in the architectural field are also working to solve the problem. Therefore, an important part of this design has been applied in a variety of ways. We observed and analyzed the current status of students using the Center for International Exchange at Youngnam University and the operational patterns of the school"s side and found problems. Through this project, the Center for International Exchange was able to offer an alternative plan to make the center a place where Korean students and foreign students can actively interact.