Time-evolving genetic networks reveal a NAC troika that negatively regulates leaf senescence in <i>Arabidopsis</i>

Kim, Hyo Jung,Park, Ji-Hwan,Kim, Jingil,Kim, Jung Ju,Hong, Sunghyun,Kim, Jeongsik,Kim, Jin Hee,Woo, Hye Ryun,Hyeon, Changbong,Lim, Pyung Ok,Nam, Hong Gil,Hwang, Daehee National Academy of Sciences 2018 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.115 No.21

<▼1><P><B>Significance</B></P><P>Leaf senescence is regulated in a complex manner, involving time-dependent interactions with developmental and environmental signals. Genetic screens have identified key regulators of senescence, particularly late-stage senescence regulators. Recently, time-course gene-expression and network analyses, mostly analyses of static networks, have predicted many senescence regulators. However, senescence is defined by time-evolving networks, involving the temporal transition of interactions among senescence regulators. Here, we present time-evolving networks of NAM/ATAF/CUC (NAC) transcription factors, central regulators of leaf senescence in <I>Arabidopsis</I>, via time-course gene-expression analysis of NACs in their mutants. These time-evolving networks revealed a unique regulatory module of NACs that controls the timely induction of senescence-promoting processes at a presenescent stage of leaf aging.</P></▼1><▼2><P>Senescence is controlled by time-evolving networks that describe the temporal transition of interactions among senescence regulators. Here, we present time-evolving networks for NAM/ATAF/CUC (NAC) transcription factors in <I>Arabidopsis</I> during leaf aging. The most evident characteristic of these time-dependent networks was a shift from positive to negative regulation among NACs at a presenescent stage. ANAC017, ANAC082, and ANAC090, referred to as a “NAC troika,” govern the positive-to-negative regulatory shift. Knockout of the NAC troika accelerated senescence and the induction of other <I>NAC</I>s, whereas overexpression of the NAC troika had the opposite effects. Transcriptome and molecular analyses revealed shared suppression of senescence-promoting processes by the NAC troika, including salicylic acid (SA) and reactive oxygen species (ROS) responses, but with predominant regulation of SA and ROS responses by ANAC090 and ANAC017, respectively. Our time-evolving networks provide a unique regulatory module of presenescent repressors that direct the timely induction of senescence-promoting processes at the presenescent stage of leaf aging.</P></▼2>

초,중,고 학생의 과학 정의적 영역 성취도 비교 분석

김수연 ( Sue Yeon Kim ),김효남 ( Hyo Nam Kim ) 한국교원대학교 초등교육연구소 2012 초등교과교육연구 Vol.16 No.-

이 연구는 초·중고 학생들의 과학 정의적 특성을 비교 분석하여 과학 정의적 영역에 대한 학생들의 특성을 알아보고, 더 나아가 초·중·고 학생들에게 바람직한 과학적 인식, 흥미, 태도를 함양하여 앞으로의 과학 교육의 내용과 방향을 제시하고자 하는데 목적이 있다. 이를 위해 2011년 2월에 초중고 학생 595을 대상으로 과학의 정의적 특성을 조사하였다. 본 연구의 결과는 과학 정의적 특성의 평균 점수가 초등학교 5학년에서 중학교2학년으로 올라가면서 통계적으로 유의하게(p<.05) 하락한 후 고등학교 1학년에서 상승하는 것으로 나타났다. 또한 남학생이 여학생보다 통계적으로 유의하게(p<.05) 높은 점수가 나타났다. 초등학교 5학년과 고등학교 1학년은 과학적 태도에서 유의미한 차이가 나타나지 않았으며, 중학교 2학년에서는 과학에 대한 인식에서 유의미한 차이가 나타나지 않고 있다. 본 연구 결과에 의하면 초등학교에서 중·고등학교로 진학하면서 과학에 대한 정의적 특성 성취 점수가 낮아지는 것을 보면 학생들에게 과학 수업에 대한 흥미와 태도를 높일 수 있도록 과학교육과정에서 내용과 방향에 대한 개선을 모색해야 할 필요가 있다. 또한 여학생의 과학에 대한 인식, 흥미, 태도를 향상 시킬 수 있는 교수-학습 과정을 모색하며 과학의 성취 수준에 대한 계속적인 분석을 통해 과학 교육의 질적 향상을 해야 한다고 생각한다. The purpose of this study was to investigate students` achievement of science affective domain. Achievement of science-related affective domain of elementary, middle, and high school students according to grades and gender was analyzed. The number of students who responded the questionnaire of science-related affective domain was 595, consisted of 172 elementary school students, 193 middle school students and 230 high school students in the same city. The students answered were 302 boys and 293 girls. The questionnaire of science-related affective domain developed by Hyo-Nam Kim and her colleagues was used. The questionnaire consisted of cognition of science, interest toward science, and scientific attitude. The reliability of the instrument was .86. The result of this study are as follows: First, the fifth graders showed the highest achievement of science-related affective domain, and the tenth graders were followed. The middle school students showed the lowest achievement of science-related affective doaim. Second, the boys showed higher achievement of science-related affective domain than girls. To maintain interest toward science and scientific attitude of students science curriculum improvement is necessary. Especially to increase girl`s and middle schoolers` achievement of science-related affective domain science teaching should consider affective domain of science education.

Ba-ferrite의 생성 및 자기적 성질에 미치는 Bi₂O₃첨가효과

남효덕 嶺南大學校 工業技術硏究所 1982 연구보고 Vol.10 No.1

The effects of additives Bi₂O₃on the solid state reaction for the system BaCO₃-Fe₂O₃and magnetic properties of Ba-ferrites. Techniques employed were thermogravimetry, X-ray diffraction analysis, scanning electron microscopy and B-H curvetracer. It was found that small additions of Bi₂O₃lowered the optimum sintering temperature and greatly improved megnetic properties of Ba-ferrites. It is estimated that the higher remanent magnetization and coercive force is due to the slower crystal growth at the lower sintering temperature. During firing, a large part ofthe Bi₂O₃volatilized, as was established from weight loss.

UHF 대역의 휴대전화 착신기능 제한 시스템의 설계 및 제작

남효덕,김종석,김병철 嶺南大學校 工業技術硏究所 2001 工業技術硏究所論文集 Vol.29 No.2

As demands grow for restricting use of cellular phones by attendants in the public places such as conference rooms, churches, and playhouses etc., a call blocking system against UHF band cellular signals is developed for other attendants who do not want to be disturbed by the phone rings. The idea of preventing a cellular phone from ringing was developed from the fact that the system radiates interferent signals having 0.1 to 0.05 watts of CW wave, makes it possible to increase the error rates of output signal of PSK modem, and hence makes the cellular phone Impossible to receive the right call signal. The system designed in this study was set up and tested in the several public places and found itself very effective.

부분수산법에 의한 PZT 세라믹스의 제작 및 압전특성

남효덕,강성환 嶺南大學校 基礎科學硏究所 1991 基礎科學硏究 Vol.11 No.-

?? (hereafter referred as PZT) powder was prepared by partial oxalate method using ?? powder (hereafter referred as ZTO) and lead nitrate and oxalate powders. The piezoelectric properties of ceramics sintered from the resulting PZT powder at low temperatures were also studied. ZTO powder was derived by hydrothermal processing using both ZrO₂and TiO₂powders at 1100,1200 and 1300℃. The ZTO powder was then dispersed in oxalic acid followed by the addition of lead nitrate to provide intimate homegeneous mixing of lead ions around each ZTO particle. The presence of single perovskite phase of PZT powder which was calcined about 710℃ was revealed from the X-ray diffraction pattern. From particle size analysis, the average particle size produced by partial oxalate method was smaller than that by the conventional mixed oxide technique. The resulting PZT powder was sintered to dense body having the density of 7.9g/㎤ above 1100℃, which is somewhat lower than the sintering temperature by the conventional techniques. The dielectric and piezoelectric properties of PZT ceramics sintered from the powder prepared by partial oxalate method were measured, and the results showed improved properties over the conventional solid-state reaction tchnique. In particular, the powder prepared from the ZTO calcined at 1100℃ proved to be the best among the powders investigated in this study.

옥소화합물 CTR의 제작 및 그 전기적 특성

남효덕 嶺南大學校 工業技術硏究所 1981 연구보고 Vol.9 No.2

(Ag ₁-??Cu??)₂Cdl₄(0 ≤x≤1) critical temperatue resistances (CTR) were fabricated by sintering the mixture of Cul, AgI and CdI₂ at 260℃ for one hour. The electerical characteristics of the CTR were also investigated. The x-dependent critical temperature for the CTR was between 30 and 60℃ and Φ value of the fabricated CTR was about 3.4 for x=0.5 sample.

안드로이드 기반 소셜 네트워크 서비스를 지원하는 '슈게더' 설계 및 구현

정효남,손예진,황준 서울여자대학교 컴퓨터과학연구소 2011 정보기술논문지 Vol.9 No.-

최근 페이스북, 트위터 그리고 카카오톡과 같은 SNS (Social Network Service)는 많으 사람들에게 인기를 얻고 있다. 사용자들은 SNS를 통해 자신의 일상을 다른 사람들에게 가시화하고, 오프라인에서 서로 모르는 사람과 친구 관계를 맺으며 서로의 생각이나 정보 등을 실시간으로 공유한다. 또한 SNS을 통해 연구 설문조사가 이루어지기도 하고, 기업은 마케팅, PR활동 그리고 고객 관리까지 SNS을 이용하고 있다. 본 논문에서는 SNS가 가진 장단점을 면밀히 분석하여 구글의 개방형 모바일 플랫폼인 안드로이드기반의 소셜 네트워크 애플리케이션, '슈게더'를 제작하였다. '슈게더'애플리케이션을 이용해 서울여대 학생들은 모르고 지냈던 사람들과의 관계 형성을 할 수 있으며, 교내에서 본인의 관심사를 타인과 함께 나눌 수 있는 효과를 기대할 수 있다.

수강 등록 데이터의 빈출 패턴을 이용한 학업 진척도 및 상태 분석을 위한 시퀀스 데이터 마이닝

정효남·전성희·황준 서울여자대학교 컴퓨터과학연구소 2014 정보기술논문지 Vol.12 No.-

유한요소법과 경계요소법을 이용한 음향트랜스듀서의 음향방사 특성 해석

남효덕,서희돈,고영준,장호경 嶺南大學校 工業技術硏究所 2001 工業技術硏究所論文集 Vol.29 No.2

The acoustic characteristics of the acoustic transducer was simulated by using the finite element method(FEM) and boundary element method(BEM). After meshing the inside closed boundary of the acoustic transducer, pressure gradients, isobaric lines, directivity characteristics and acoustic impedances were calculated by using the FEM and characteristics of 3-D free field sound pressure, directivity characteristics and radiation efficiency were simulated by using the BEM. It was shown that the usefulness of the design and the fabrication for the acoustic transducer from the results.

Mn을 첨가한 (Pb₁_xSrx) (Zr₁_zTiz)O₃계 압전세라믹스의 전기적 특성

남효덕,김응수 嶺南大學校 工業技術硏究所 1988 연구보고 Vol.16 No.2

(Pb₁_x Srx) (Zr?? Tj??)O₃piezoelectric ceramics were fabricated by the ordinary firing method at the temperature range of 1180~1240℃. The effects of the additive MnCO₃and substituent SrCO₃on the sintering and the electrical properties were investigated. The experimental results indicated that the specimens containing 5mol% SrCO₃and 0.6wt% MnCO₃, sintered at 1220℃, showed the best piezoectrical and dielectrical characteristics. Electromechanical coupling coefficient (kp) increased while the Curie temperature(Tc) decreased with increasing of SrCO₃ amount. Additive MnCO₃was shown to contribute to improve mechanical quality factor(Qm), which is one of important characteristics of piezoelectric ceramics.