Calcineurin tax-6 regulates male ray development and counteracts with kin-29 kinase in Caenorhabditis elegans

김승현,정하나,안주홍,이선경 한국통합생물학회 2019 Animal cells and systems Vol.23 No.6

Phosphorylation is one of the critical protein modifications, which can lead to changing the activity of the proteins and regulating a variety of biological processes. Therefore, it is essential to properly maintain the phosphorylation level on proteins by balancing the activity of kinases and phosphatases. In this study, we report that calcineurin, a serine/threonine phosphatase, counteracts with a salt inducible kinase (SIK) to control male tail development in Caenorhabditis elegans. The counteracting regulation is cell lineage-dependent; the number of defective rays from T lineage in animals lacking calcineurin tax-6 is decreased by knock-down of SIK kin-29. This result is in contrast with the knock-down of bone marrow protein (BMP) receptor kinase sma-6, which slightly aggravates the T lineage defect. Also, sma-6 knock-down results in modest defect in ray 1 of V5 lineage in the absence of tax-6 activity. Finally, knock-down of a tyrosine phosphatase cdc-25.3 does not affect the defective ray phenotype of calcineurin tax-6 loss-offunction( lf) mutants. Altogether, these results suggest that balanced phosphorylation mediated by tax-6 and kin-29 is required for proper development of T lineage rays, and tax-6 and sma-6 may function in a parallel pathway in the developmental process of V5 lineage ray 1. This study emphasizes the elaborated developmental process of male ray formation, in which carefully coordinated expression of various genes is essential.

Wicking Property of Graft Material Enhanced Bone Regeneration in the Ovariectomized Rat Model

김승현,안태호,한명호,배춘식,Daniel S. Oh 한국조직공학과 재생의학회 2018 조직공학과 재생의학 Vol.15 No.4

BACKGROUND: Recruitment and homing cells into graft materials from host tissue is crucial for bone regeneration. METHODS: Highly porous, multi-level structural, hydroxyapatite bone void filler (HA-BVF) have been investigated to restore critical size bone defects. The aim was to investigate a feasibility of bone regeneration of synthetic HA-BVF compared to commercial xenograft (Bio-Oss). HA-BVF of 0.7 mm in average diameter was prepared via template coating method. Groups of animals (n = 6) were divided into two with normal (Sham) or induced osteoporotic conditions (Ovx). Subsequently, subdivided into three treated with HA-BVF as an experiment or Bio-Oss as a positive control or no treatment as a negative control (defect). The new bone formation was analyzed by micro-CT and histology. RESULTS: At 4 weeks post-surgery, new bone formation was initiated from all groups. At 8 weeks post-surgery, new bone formation in the HA-BVF groups was greater than Bio-Oss groups. Extraordinarily greater bone regeneration within the Ovx-HA group than Sham–Bio-Oss or Ovx–Bio-Oss group (p\0.05). CONCLUSION: This study suggests that the immediate wicking property of HA-BVF from host tissue activates a natural healing cascade without the addition of exogeneous factors or progenitor cells. HA-BVF may be an effective alternative for repairing bone defects under both normal and osteoporotic bone conditions.

감정평가업에 있어서 서비스 요인과 고객만족의 관계에 대한 고찰

김승현,민규식,Kim, Seung-Hyun,Min, Gu-Sik 한국전자통신학회 2012 한국전자통신학회 논문지 Vol.7 No.3

The future of appraisal industry looks negative in the reality of change of the property market and over-competition of the field. Unless Constituent members of appraisal industry cope actively with the changing circumstances the profit structure of their company will get worse and they will finally fall behind in the competition. The best policy to survive from the changing circumstances in the limited appraisal market is to provide better service and improve its structure in order to have differential competitiveness. The purpose of this study is to describe the relation between the service factors of appraisal industry and customer satisfaction for providing more effective and high quality appraisal service. 감정평가업계도 근래 부동산 시장의 장기침체와 더불어 평가시장의 축소 및 그에 따른 과당경쟁이 심화되고 있다. 감정평가업에 있어 서비스 요인은 공정성, 객관성, 충실성, 공시업무 수행능력, 연구개발 기여도 등이 있으며 평가업계는 최상의 감정평가를 통하여 고객의 만족도를 높이고 이러한 노력은 고객의 평가를 통하여 감정평가 산업이 지속적으로 발전할 수 있게 할 것이다.

Development of virtual reality visualization model (VRVM) with relative spatiotemporality for visual contents in molecular toxicology education

김승현,Heo Ryoun,Chung Yeonji,Park Sunghyo,Kim Jung Min,Kwon Michelle P.,Park Gil-Hong,Kim Meyoung-Kon 대한독성 유전단백체 학회 2021 Molecular & cellular toxicology Vol.17 No.1

Background Visualizing educational contents makes learning more efficient and effective especially in the area such as molecular toxicology, which is time consuming and intellectually taxing to learn. Objective A design principle based on cognitive neuroscience was developed for spatiotemporality of information and optimized virtual reality (VR) for molecular toxicology. We modeled VR with the tricarboxylic acid (TCA) cycle, a major working mechanism of several toxic poisons such as fluoroacetate, malonate, arsenite, etc. to improve the effectiveness of education in molecular toxicology for better recall compared to traditional education methods. Results We devised an educational system and theoretical basis for virtual reality visualization model (VRVM), as integrated research in this area had been insufficient thus far. We found that VRVM has positive effects on learning and memory when teaching complex topics such as molecular toxicology in our previous study. Conclusions This study has three main components: (1) construction of VR hardware/software (HW/SW) system; (2) creation of VR space design guide; and (3) verification of VRVM spatiotemporality. Consequently, we developed VRVM for the TCA cycle of toxicological mechanism to improve the study habits of medical students in the context of molecular toxicology studies. To continuously expand this approach for future educational applications, up-to-date findings in areas such as cognitive neuroscience and psychology for studying molecular toxicology should be incorporated to strengthen concepts, logic, and physical models of visualization.

‘미래 사회 대비 국어교육 평가의 방향 탐색’에 대한 토론문

김승현 한국어교육학회(구 한국국어교육연구학회) 2019 한국어교육학회 학술발표논문집 Vol.2019 No.1

학문 목적 한국어 쓰기 평가 기준 개발을 위한 기초 연구

김승현,홍은실 반교어문학회 2019 泮橋語文硏究 Vol.0 No.53

We recognized that there is a need for writing evaluation standard in Korean for academic purpose. This study aims to establish valid writing evaluation standards through identifying evaluation factors and verifying them. Based on literature review, we defined writing for academic purpose as communicative behavior using acceptable expressions, styles and format in the academic discourse community where the writer belongs to. We implemented Delphi method 1 three rounds. On the first round, we tried to provide wide range of opinion with open-ended question to focus group and we derived 7 to 8 evaluation factors per each content, organization and expression category. We asked focus group to proceed weighted value determination on each evaluation factor under three categories on the second and the third round Delphi. Finally we established writing evaluation standard in Korean for academic purpose. 본 연구는 학문 목적 한국어 쓰기의 평가 기준에 대한 필요성에 대한 인식을 바탕으로 구체적인 평가 요소의 도출과 검증을 통해 타당성 있는 평가 기준을 마련하고자 하였다. 우선 선행 연구들을 통해 학문 목적 쓰기는 필자가 자신을 둘러싸고 있는 학문적 담화 공동체에서 수용 가능한 일정한 표현, 문제, 형식 등을 사용하여 의사소통하는 행위라고 규정하였다. 그리고 1~3차에 걸친 델파이 조사를 실시하여 학문 목적 한국어 글쓰기를 위한 평가 기준을 설정하고자 하였다. 1차는 개방형 질문으로 조사지를 구성하여 다양한 의견을 수렴하고자 하였으며, 그 결과 내용, 조직, 표현의 영역별로 각 7~8개의 평가 요소를 도출하였다. 이어지는 2~3차에 걸친 델파이 조사에서는 텍스트 유형별(설명, 논증, 자기 표현적)로 영역별 가중치 판단을 통해 각 평가 요소의 중요도를 판정하였으며, 결과 분석을 통해 학문 목적 한국어 쓰기의 평가 기준을 제안하였다.

서답형 문항 분석을 통한 국어과 평가 방안 개선 연구

김승현,이상일 한국국어교육학회 2015 새국어교육 Vol.0 No.105

This study aims to analyze student responses to constructed response items of Korean language in NAEA and to draw implications for enhancing curriculum, and teaching and learning for Korean language education. Analysis target items are two constructed response items, one item each from middle school and high school Korean language in the 2013 NAEA. First of all, answers for constructed response items written by students from sample-based testing schools were classified by type. Utilizing the distribution curve of frequency and rate per achievement score, the characteristics of each type were analyzed in relation to the achievement level. The results showed that it is hard to separately evaluate student’s capability related to the achievement level of the domain being tested. It is also indicated that the characteristics and the difficulty level of texts have a great influence on how students solve problems. Even Proficient level students lack a basic understanding of grammar and have hard time expressing their thoughts;Basic and Below-basic students showed high non-response rate. 본 연구는 국가수준 학업성취도 평가의 국어과 서답형 문항에 대한 학생 반응을 유형별, 성취수준별로 분석하여 국어과 교수․학습 및 교육과정 개선, 서답형 평가 방법 개선을 위한 시사점을 도출하고자 하였다. 분석 대상으로는 중학교와 고등학교 국어과 서답형 문항을 각각 1개씩 선정하였으며, 먼저 표집학교 학생이 작성한 답안의 반응 양상을 유형화하고 빈도를 조사한 후, 각 유형의 성취도 점수별 빈도 분포 및 비율 분포 곡선을 활용하여 성취수준과 연계한 분석을 실시하였다. 연구 결과 현행 국어과 서답형 문항은 성취기준과 관련한 학생들의 역량을 온전히 평가하지 못하고 있으며, 제시되는 텍스트의 성격과 난이도가 문제 해결 과정에 미치는 영향력이 큰 것으로 나타났다. 보통학력 학생들은 국어지식에 대한 이해 및 자신의 생각을 표현하는 능력이 미흡했고, 기초학력 이하 학생들은 상대적으로 무응답 비율이 높았다. 이러한 결과를 바탕으로 출제 영역의 성취기준에 관한 학생들의 역량을 평가할 수 있는 문항 설계, 성취기준 달성에 도움이 되는 적합한 자료의 제시 등 문항 출제상의 개선점을 제안하였고, 국어지식 함양 및 표현 능력 향상을 위한 교수․학습 강화의 필요성을 제기하였다.

Which ideas are more likely to be implemented in online user innovation communities? An empirical analysis

김승현 ELSEVIER SCIENCE BV 2016 DECISION SUPPORT SYSTEMS Vol.84 No.-

가수분해 산물 분포를 이용한 급속혼화강도가 화학적 인 제거 효율에 미치는 영향의 규명

김승현,윤동수,문병현 대한상하수도학회 2011 상하수도학회지 Vol.25 No.3

Mechanism of rapid mixing effect on chemical phosphorus removal is evaluated in this study. Assuming that chemical phosphorus removalis unaffected by mixing time, only rapid mixing intensity is evaluated. In order to find out the mechanism, it is hypothesized that rapid mixing affects the Al hydrolysis speciation, and that formation of more monomeric species (Ala) results in better removal of phosphorus. According to a ferron assay, more Ala formed at higher mixing intensity than at lower intensity. Subsequent experiments revealed that better phosphorus removal was obtained at higher intensity than at lower intensity, in terms of the molar ratio of Aladded/Premoved. The proposed hypothesis was proved in this study. Chemical phosphorus removal is affected by rapid mixing intensity due to its effect on the Al hydrolysis speciation.

Intramolecualr cyclization of a dipyrromethane by an electrophilic aromatic substitution reaction producing a new chiral compound

김승현,김성국 한국자기공명학회 2018 Journal of the Korean Magnetic Resonance Society Vol.22 No.4

Dipyrromethane 2 functionalized with 3-chloropropyl group on the meso carbon undergoes an unusual intramolecular electrophilic aromatic substitution reaction in the presence of NaN3 instead of a simple nucleophilic substitution reaction. As a result, a new chiral dipyrromethane 1 was synthesized. In this reaction, the β-carbon of the pyrrole ring functions as a nucleophile while the carbon next to the chlorine atom acts as an electrophile. Interestingly, this reaction progresses even in the absence of an acid catalyst. Compound 1 was fully characterized by 1H-1H and 1H-13C COSY NMR spectroscopic analyses and the high resolution EI mass spectrometry.