Long-read sequencing reveals intra-species tolerance of substantial structural variations and new subtelomere formation in <i>C. elegans</i>

Kim, Chuna,Kim, Jun,Kim, Sunghyun,Cook, Daniel E.,Evans, Kathryn S.,Andersen, Erik C.,Lee, Junho Cold Spring Harbor Laboratory Press 2019 Genome research Vol.29 No.6

<P>Long-read sequencing technologies have contributed greatly to comparative genomics among species and can also be applied to study genomics within a species. In this study, to determine how substantial genomic changes are generated and tolerated within a species, we sequenced a <I>C. elegans</I> strain, CB4856, which is one of the most genetically divergent strains compared to the N2 reference strain. For this comparison, we used the Pacific Biosciences (PacBio) RSII platform (80×, N50 read length 11.8 kb) and generated de novo genome assembly to the level of pseudochromosomes containing 76 contigs (N50 contig = 2.8 Mb). We identified structural variations that affected as many as 2694 genes, most of which are at chromosome arms. Subtelomeric regions contained the most extensive genomic rearrangements, which even created new subtelomeres in some cases. The subtelomere structure of Chromosome VR implies that ancestral telomere damage was repaired by alternative lengthening of telomeres even in the presence of a functional telomerase gene and that a new subtelomere was formed by break-induced replication. Our study demonstrates that substantial genomic changes including structural variations and new subtelomeres can be tolerated within a species, and that these changes may accumulate genetic diversity within a species.</P>

“소나기” 수업건의

신춘애(Sin Chunae) 길림성민족사무위원회 2016 중국조선어문 Vol.203 No.-

무역전시회와 일반전시회 참가기업의 참가결정요소와 참가성과 비교분석

전동석(Dong-Suk Chuna),남경두(Kyung-Doo Namb) 한국무역연구원 2016 무역연구 Vol.12 No.2

The purpose of this study is to provide a development plan for domestic trade shows in Korea. Specifically, this study compares domestic trade exhibitions and public shows relative to the factors affecting participation and satisfaction of exhibitors. One of the most important results of the study revealed that exhibitors’ participation in trade shows was more affected by the core values provided by exhibitions such as past show results and the number of qualified buyers who can build business leads. Furthermore, the comparison study results between the two show groups also showed that on-site sales was one of the key satisfactory factors for exhibitors participating in public shows, whereas one to one business meetings between buyers and exhibitors and the number of contracts being signed during the show period was rated as the most important factor for exhibitors attending trade shows. Based on these key findings, a development plan for future domestic trade shows was discussed.

한국 영아의 애착의 질에 대한 측정도구로서의 '낯선 상황'이 가지는 문제점

정진나 경복대학 2002 京福論叢 Vol.6 No.-

애착분류체계에 대한 문화적으로 민감한 모델 구축의 필요성을 강조하기 위해 본 연구에서는 부모신념과 영아 애착행동에 있어서의 문화적 다양성을 살펴보았다. 많은 애착연구들은 미국에서 수행되었든 다른 나라에서 수행되었든 Ainsworth에 의해 개발된 '낯선 상황'에 기초하고 있다. 비교문화 연구가들은 이 낯선 상황이 Baltimore 영아들의 반응을 도출하기 위해 고안된 문화 특정적 실험실 절차로서 개발된 것이라는 점을 지적해왔다. 낯선 상황은 원래 미국 백인 중산층들에게 만연된 조건들에 맞춰서 짜여진 절차이기 때문이다. 그러므로 이 절차는 영아 양육의 문화적 조건에 대한 충분한 자연관찰 없이 다른 집단에게 무분별하게 사용되어질 수는 없다. 미국 영아들에 비해 한국 영아들은 부모와의 격리나 낯선 사람에 대한 경험이 상대적으로 부족하다. 이러한 경험부족으로 인해 낯선 상황 실험절차가 한국 영아들에게 상대적으로 지나친 스트레스를 유발시킬 수 있으며 결국 이는 애착의 질을 평가하기 위한 타당한 측정도구가 아닌 것이다. With an attempt to emphasize the need for culturally-sensitive model of attachment classification system, this review examines cultural variations in parental beliefs and attachment behaviors. Much attachment research, whether conducted in the Unite3 States or elsewhere, is based on the Strange Situation developed by Ainsworth. Cross-cultural researchers have pointed out that the Strange Situation was invented as a culture-specific laboratory procedure designed to elicit from the Baltimore infants responses. It attuned to conditions prevailing among White, middle-class Americans. Therefore, it cannot be used in other groups without the naturalistic observations of their prevailing conditions of infant care. Compared to American infants, Korean infants have relatively inexperienced with separation or strangers. As a result, the Strange Situation might be too stressful for them, and be therefore invalid.

Transcriptomic Analysis of Cellular Senescence: One Step Closer to Senescence Atlas

Kim, Sohee,Kim, Chuna Korean Society for Molecular and Cellular Biology 2021 Molecules and cells Vol.44 No.3

Senescent cells that gradually accumulate during aging are one of the leading causes of aging. While senolytics can improve aging in humans as well as mice by specifically eliminating senescent cells, the effect of the senolytics varies in different cell types, suggesting variations in senescence. Various factors can induce cellular senescence, and the rate of accumulation of senescent cells differ depending on the organ. In addition, since the heterogeneity is due to the spatiotemporal context of senescent cells, in vivo studies are needed to increase the understanding of senescent cells. Since current methods are often unable to distinguish senescent cells from other cells, efforts are being made to find markers commonly expressed in senescent cells using bulk RNA-sequencing. Moreover, single-cell RNA (scRNA) sequencing, which analyzes the transcripts of each cell, has been utilized to understand the in vivo characteristics of the rare senescent cells. Recently, transcriptomic cell atlases for each organ using this technology have been published in various species. Novel senescent cells that do not express previously established marker genes have been discovered in some organs. However, there is still insufficient information on senescent cells due to the limited throughput of the scRNA sequencing technology. Therefore, it is necessary to improve the throughput of the scRNA sequencing technology or develop a way to enrich the rare senescent cells. The in vivo senescent cell atlas that is established using rapidly developing single-cell technologies will contribute to the precise rejuvenation by specifically removing senescent cells in each tissue and individual.

Aminolysis of 2,4-Dinitrophenyl 2-Furoate and 2-Thiophenecarboxylate: Effect of Modification of Nonleaving Group from Furoyl to Thiophenecarbonyl on Reactivity and Mechanism

엄익환,Se-Won Min,Sun-Mee Chuna 대한화학회 2008 Bulletin of the Korean Chemical Society Vol.29 No.7

Second-order rate constants have been determined spectrophotometrically for reactions of 2,4-dinitrophenyl 2- thiophenecarboxylate (2) with a series of alicyclic secondary amines in 80 mol % H2O/20 mol % DMSO at 25.0 ± 0.1 oC. The Brønsted-type plot exhibits a downward curvature, i.e., the slope decreases from 0.74 to 0.34 as the amine basicity increases. The pKa at the center of the Brønsted curvature, defined as pKa o, has been determined to be 9.1. Comparison of the Brønsted-type plot for the reactions of 2 with that for the corresponding reactions of 2,4-dinitrophenyl 2-furoate (1) suggests that reactions of 1 and 2 proceed through a common mechanism, although 2 is less reactive than 1. The curved Brønsted-type plot has been interpreted as a change in RDS of a stepwise mechanism. The replacement of the O atom in the furoyl ring by an S atom (1 → 2) does not alter the reaction mechanism but causes a decrease in reactivity. Dissection of the apparent second-order rate constants into the microscopic rate constants has revealed that the k2/k–1 ratio is not influenced upon changing the nonleaving group from furoyl to thiophenecarbonyl. However, k1 has been calculated to be smaller for the reactions of 2 than for the corresponding reactions of 1, indicating that the C=O bond in the thiophenecarboxylate 2 is less electrophilic than that in the furoate 1. The smaller k1 for the reactions of 2 is fully responsible for the fact that 2 is less reactive than 1.

Aminolysis of 2,4-Dinitrophenyl 2-Furoate and 2-Thiophenecarboxylate: Effect of Modification of Nonleaving Group from Furoyl to Thiophenecarbonyl on Reactivity and Mechanism

Um, Ik-Hwan,Min, Se-Won,Chuna, Sun-Mee Korean Chemical Society 2008 Bulletin of the Korean Chemical Society Vol.29 No.7

Second-order rate constants have been determined spectrophotometrically for reactions of 2,4-dinitrophenyl 2- thiophenecarboxylate (2) with a series of alicyclic secondary amines in 80 mol % $H_2O$/20 mol % DMSO at 25.0 ${\pm}$ 0.1 ${^{\circ}C}$. The Brønsted-type plot exhibits a downward curvature, i.e., the slope decreases from 0.74 to 0.34 as the amine basicity increases. The $pK_a$ at the center of the Brønsted curvature, defined as $pK_a^o$, has been determined to be 9.1. Comparison of the Brønsted-type plot for the reactions of 2 with that for the corresponding reactions of 2,4-dinitrophenyl 2-furoate (1) suggests that reactions of 1 and 2 proceed through a common mechanism, although 2 is less reactive than 1. The curved Brønsted-type plot has been interpreted as a change in RDS of a stepwise mechanism. The replacement of the O atom in the furoyl ring by an S atom (1 $\rightarrow$ 2) does not alter the reaction mechanism but causes a decrease in reactivity. Dissection of the apparent second-order rate constants into the microscopic rate constants has revealed that the $k_2/k_{-1}$ ratio is not influenced upon changing the nonleaving group from furoyl to thiophenecarbonyl. However, $k_1$ has been calculated to be smaller for the reactions of 2 than for the corresponding reactions of 1, indicating that the C=O bond in the thiophenecarboxylate 2 is less electrophilic than that in the furoate 1. The smaller k1 for the reactions of 2 is fully responsible for the fact that 2 is less reactive than 1.

아버지의 결혼만족도 및 양육태도와 유아의 사회적 능력간의 관계

우정희,이미숙,전춘애 대한가정학회 2003 Family and Environment Research Vol.41 No.12

This study investigated the relationship between fathers marital satisfaction, child rearing attitude and children s social competence. The subjects of this study were 274 fathers of 4 - 5 year old children who enrolled in kindergartens located in Seoul and metropolitan areas. Data was analyzed using the following methods: frequency, percentage, mean, Pearson s correlation andpis, multiple regression Mi and Cronbach's a. As a result of thii study, it was revealed that there were a significant relationship between the marital satisfaction and child rearing attitude of fathers and the social competence of children. However, this study showed that the child rearing attitude rather than the marital satisfaction of fathers was the more influential on the social competence of children.

Components-dependent magnetic switching of CoFeB and CoFeSiB magnetic tunnel junction

T. X. Wang,D. K. Kim,B. S. Chuna,Y. K. Kima 한국자기학회 2007 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Two kinds of amorphous Co-rich magnetic amorphous films of CoFeB and CoFeSiB of different compositions were prepared by magnetron sputtering and applied as ferromagnetic electrodes in magnetic tunnel junctions (MTJs). The spin polarization of CoFeB is rather sensitive to its composition, but not necessarily to magnetic switching behavior. The switching fields were around 30 Oe for Co contents ranging from 60 to 85 at. %). On the contrary, the switching behavior of CoFeSiB was very sensitive to its Co content (5 to 20 Oe as Co content increased from 71 to 81 at. %), with tunneling magneto-resistance (TMR) ratio saturated when Co surpass 74 at. %. Comparatively, CoFeSiB can be a good candidate for future high density spin memory devices to reduce the switching field or critical current with its excellent adjustable soft magnetic behavior and high spin polarization by properly adjust the contents of metalloid elements Si and B. The Landau-Lifshitz-Gilbert micromagnetics simulation was employed to investigate the size dependenceof MTJs with magnetically soft CoFeSiB free layer with ellipsoidal cells with sizes from 1 μm to 60 nm, using the magnetic parameters extracted from the experiment. The switching field needed was smaller compared to that of the Co [1] and CoFe [2] junctions but slightly larger than that of the NiFe [3] junction at corresponding sizes reported. Above-mentioned features associated with amorphous CoFeSiB junction appear attractive for MRAM applications.

온도 및 하중 영향을 고려한 임피던스 기반 조류발전용 재킷 구조물의 장기 건전성 모니터링

민지영(Min,Jiyoung),김유청(Kim,Yucheong),윤정방(Yun,Chuna-Bang),이진학(Yi,Jin-Hak) 대한토목학회 2011 대한토목학회논문집 A Vol.31 No.5A

일반적으로 해양개발을 위하여 사용되는 재킷식 해양 구조물은 염분, 조류, 파도, 바람 등 극심한 환경적 요인에 의해 육상 시설물에 비해 열악한 환경에 노출되어 있으나, 이러한 구조물의 구조적 안전성 및 성능 확보를 위한 모니터링 시스템의 적용사례는 그다지 많지 않다. 임피던스 기반의 구조물 건전성 모니터링은 구조물의 국부적인 손상을 모니터링하는 기술로서 최근 실 구조물에의 적용에 대한 연구가 국내외에서 활발하게 이루어지고 있으나, 온도, 하중 등의 환경적 요인에 의한 영향을 최소화하고 손상에 의한 특성만을 효과적으로 추출하는 기술은 미흡한 상태이다. 따라서 본 연구에서는 재킷식 조류발전 지지구조물의 축소모형을 제작하여 온도와 정적 하중이 변하는 환경 하에서 임피던스 기반의 국부적 손상 모니터링에 관한 연구를 수행하였다. 환경에 의한 영향을 보상하기 위하여 기존의 손상지수에 대해 주성분 분석을 수행하였으며 환경 변화에 민감하게 반응하는 주성분을 선택하여 제거하였다. 이 후 손상지수를 모니터링한 결과, 제안된 주성분 분석 기반 접근법이 환경 영향 하에서의 장기 모니터링에 유효하게 사용될 수 있음을 확인하였다. Jacket-type offshore structures are always exposed to severe environmental conditions such as salt, high speed of current, wave, and wind compared with other onshore structures. In spite of the importance of maintaining the structural integrity for offshore structure, there are few cases to apply structural health monitoring (SHM) system in practice. The impedance-based SHM is a kind of local SHM techniques and to date, numerous techniques and algorithms have been proposed for local SHM of real-scale structures. How-damage features from impedance signals. In this study, the impedance-based SHM was carried out on a 1 /20-scaled model of an Uldolmok current power plant structure under changes in temperature and transverse loadings. Principal component analysis (PCA) was applied using conventional damage index to eliminate principal components sensitive to environmental change. It was found that the proposed PCA-base approach is an effective tool for long-term SHM under significant environmental changes.