• Title/Summary/Keyword: quiescent

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Fluridone affects quiescent centre division in the Arabidopsis thaliana root stem cell niche

  • Han, Woong;Zhang, Hanma;Wang, Myeong-Hyeon
    • BMB Reports
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    • v.43 no.12
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    • pp.813-817
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    • 2010
  • Plants undergo cell division throughout their life in order to maintain their growth. It is well known that root and shoot tip of plants possess meristems, which contain quiescent cells. Fluridone (1-methyl-3-phenyl-5-(3-trifluromethyl (phenyl))-4-(1H)-pyridinone) is an established inhibitor of both ABA and carotenoid biosynthesis. However, the other functions of fluridone remain undiscovered. In this report, we provide experimental evidence that fluridone plays a role in the division of the quiescent centre of the Arabidopsis root meristem. This study examined the effects of exogenous fluridone and ABA on the development of the stem cell niche in Arabidopsis root. We show that fluridone promoted the division of stem cells in the quiescent centre, whereas exogenous ABA suppressed quiescent centre division. Furthermore, we established a novel regulatory function for fluridone by demonstrating that it plays an important role in postembryonic development.

The Motion of Plasma in an Excited Quiescent Filament

  • Song, Dong-Uk;Chae, Jong-Chul
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.48.2-48.2
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    • 2010
  • Quiescent filaments are bigger, more stable, and longer lived than active region filaments. So, the shape of a quiescent filament changes little during its lifetime and a fast motion of plasma rarely occurs. But when it is dynamically influenced by external phenomena, a rapid motion of plasma may temporarily occur. By analyzing the motion of plasma we can infer some of the magnetic structure permeating such an excited quiescent filament. We analyzed the H$\alpha$ images of a quiescent filament in the northern hemisphere that was observed at Big Bear Solar Observatory on 2004 August 2, and found that: 1) the filament was excited by a flare that occurred in a remote active region located in the southern hemisphere, 2) By this excitation, a part of the filament moved vertically upward and horizontally out of main body, and then it stayed there without much motion. Then after it moved vertically downward and horizontally to the main body, 3) the final position of plasma, however, was not the same as the initial position, being about 14Mm above it. We suggest that the filament was initially in a more or less static equilibrium. The excitation of the filament broke the initial equilibrium, and then brought about a new one that is different from the original one. Since the filament should have magnetic field, it is likely that both the equilibria may have been maintained by diplike magnetic structures. Furthermore, the transition from one equilibrium to another as we inferred should have accompanied a permanent change of magnetic configuration as well.

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Improvement of Power Consumption of Automatic Quiescent Power Cut-off Receptacle by Developing Latch Relay (래치릴레이 개발 및 적용을 통한 대기전력 자동 차단 콘센트의 효율 개선방안 고찰)

  • Kim, Ju-Chul;Lee, Joon-Ho;Kim, Jin-Tai;Kim, Sun-Gu;Lee, Sang-Joong
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.10
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    • pp.75-79
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    • 2013
  • The automatic quiescent power cut-off receptacles(QPCR from now on) have achieved a noticeable energy saving so far. The government is preparing a new code for wider promotion of the QPCRs. This paper presents a new QPCR that adopts the latch relay instead of the conventional coil-operated relay. Measurement results of the prototype have shown up to 0.22W improvement of quiescent power compared with existing products.

Study on Nucleo-Cytoplasmic Interaction by Somatic Cell Nuclear Transfer in Bovine (소 체내포 핵이식에 의한 핵-세포질 상호작용에 관한 연구)

  • 정희태;최종엽;박춘근;김정익;민동미
    • Journal of Embryo Transfer
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    • v.15 no.1
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    • pp.23-31
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    • 2000
  • This study was conducted to investigate the effects of quiescent treatment of donor cells and activation treatment time of recipient cytoplasm on nuclear remodeling and in vitro development of somatic cell-cloned bovine embryos. Serum starved, confluent and nonquiescent cycling adult skin cells were teansferred into enucleated oocytes. Nuclear transfer oocytes were activated at 30 min, 1 and 2 hrs after electrofusion. Some nuclear transfer embryos(23% to 35%) extruded a polar body, which was not affected by quiescent treatment of donor cells and activiation time of recipient cytoplasm. About 68% of nuclear transfer embryos fused with a serum starved cells has a chromatin clump, but which was not different from embryos fused with confluent(51%) and nonquiescent(47%) cells. The proportion of embryos with a single chromatin clump was sightly increased when nuclear transfer embryos were activated within 30 min after fusion(69%) compared to those were activated at 1 and 2 hrs after fusion, but there was not significantly different. Development rates to the blastocyst stage were 8.6% and 15.9% when serum starved and confluent cells were transferred, which were higher than that of control group. Developmental rate to the blastocyst stage was higher in embryos were activated within 30 min after fusion (17.3%) compared to those of embryos were activated at 1 and 2 hrs after fusion (P<0.05). From the present result, it is suggested that quiescent treatment of donor cells and activation time of recipient cytoplasm can affect the in vitro development. Quiescent plasm activation within 30 min after fusion could increase the number of embryos with a normal chromation structure, which results in increased in vitro development.

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A Study of LCCA and LCA to Evaluate Feasibility for Introducing Smart Quiescent Power Control System into Office Building (LCCA 및 LCA 분석을 이용한 오피스 빌딩에 지능형 대기전력 제어시스템 도입의 타당성 분석에 관한 연구)

  • Quan, Junlong;Lee, Seok-Jung;Choi, Hye-Mi;Kim, Kyung-Hwan;Kim, Ju-Hyung
    • Journal of the Korea Institute of Building Construction
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    • v.16 no.2
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    • pp.141-149
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    • 2016
  • Recently, in an attempt to overcome the defects of quiescent power shutdown system, smart quiescent power control system has been developed. However, due to its higher investment costs, feasibility evaluation must be conducted. While LCCA (Life Cycle Cost Analysis) model is useful to estimate net savings of alternatives that differ with respect to initial costs and operating costs, the environmental burdens are not considered. On the contrary, LCA (Life Cycle Assessment) model is suitable to assess environmental impacts associated with the stages of a product's life but it does not consider costs. In this study, a comprehensive analysis on the economic and environmental impacts of smart quiescent power control system is conducted by using LCCA and LCA model. In addition, sensitivity analysis is carried out to quantify accuracy of estimates.

Practical Fault Coverage of Supply Current Testing for Open Fault in TTL Combinational Circuits

  • Mushiaki, Yukiko;Hashzume, Masaki;Yotsuyanagi, Hiroyuki;Tamesada, Takeomi
    • Proceedings of the IEEK Conference
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    • 2000.07a
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    • pp.383-386
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    • 2000
  • There are some variations in quiescent supply current or TTL SSIs. Thus, some variations in quiescent supply current of logic circuits made of TTL SSIs will be generated. The variations make it difficult to apply supply current test methods to tests of TTL circuits. In this paper, in order to examine the applicability to R circuits, fault coverages of a supply current test method for open faults in some ISCAS-85 benchmark circuits are evaluated, Which are made of TTL LS-type SSIs. The experimental results shows that if SSIs are used for implementation having the variation of quiescent supply current within 1%, supply current test methods are applicable for the tests.

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Flame Propagation Characteristics of Propane-Air Premixed Mixtures (프로판-공기 예혼합기의 화염전파 과정에 관한 연구)

  • Bae, Choong-Sik
    • Journal of the Korean Society of Combustion
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    • v.1 no.2
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    • pp.21-29
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    • 1996
  • Flame propagation characteristics of propane-air mixtures were experimentally investigated in constant-volume combustion chambers. Flame propagation process was observed as a function of mixture strength, initial mixture temperature and initial mixture pressure in quiescent mixtures. A cylindrical combustion chamber and a spherical combustion chamber contain a pair of parallel windows through which optical access into the chamber can be provided. Laser two beam deflection method was adopted to measure the local flame propagation, which gave information on the flame size and flame propagation speed. Pressure development was also measured by a piezoelectric pressure transducer to characterize combustion in quiescent mixtures. Burning velocity was calculated from flame propagation and pressure measurements. The effect of flow on flame propagation was also investigated under flowing mixture conditions. Laser two beam method was found to be feasible in measuring flame propagation of quiescent mixtures. Flame was observed to propagate faster with higher initial mixture temperature and lower initial pressure. Combustion duration was shortened in the highly turbulent flowing mixtures.

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Low Power and High Slew-Rate OP-AMP for Large Size and High Resolution TFT-LCD Applications (대면적, 고해상도 TFT-LCD 구동용 저소비전력, High Slew Rate OP-AMP)

  • 최진철;김성중;성유창;권오경
    • Proceedings of the IEEK Conference
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    • 2003.07b
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    • pp.903-906
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    • 2003
  • In this paper, we proposed high slew-rate and low-power OP-AMP of the data driver for TFT-LCDs. Proposed OP-AMP contains newly developed rail-to-rail class-AB input circuit which enables the low-quiescent current and high slew-rate OP-AMP. The slew-rate and the quiescent current of the proposed OP-AMP are 31.2V/$\mu$sec and 5$\mu$A, respectively.

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Star-formation Properties of High-redshift (z~1) Galaxy Clusters Connected to the Large-scale Structure

  • Lee, Seong-Kook;Im, Myungshin;Hyun, Minhee;Park, Bomi;Kim, Jae-woo;Kim, Dohyung;Kim, Yongjung
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.40.2-40.2
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    • 2017
  • At local, majority of galaxies in the dense environment, such as galaxy cluster, are red and quiescent with little star-formation (SF) activity. However, a different picture emerges as we go to high redshift: (1) there exist non-negligible fraction of galaxies still forming stars actively even in dense environment, and (2) there is a significant cluster-by-cluster variation in the SF properties, such as quiescent galaxy fraction. In this presentation, we show the results of our study about the variation of quiescent galaxy fraction among high-redshift (z~1) galaxy clusters, based on the multi-object spectroscopic (MOS) observation with IMACS on the Magellan telescope. Our main result is that galaxy clusters which are connected with significant large-scale structure (LSS), well beyond the cluster scale, are more active in their SF activity, i.e., the quiescent galaxy fraction for these clusters is lower compared to the clusters which are detached from LSS.

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