• 제목/요약/키워드: Reverse function

검색결과 506건 처리시간 0.03초

식물 유전자 연구의 최근 동향 (Current status on plant functional genomics)

  • 조용구;우희종;윤웅한;김홍식;우선희
    • Journal of Plant Biotechnology
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    • 제37권2호
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    • pp.115-124
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    • 2010
  • As the completion of genome sequencing, large collection of expression data and the great efforts in annotating plant genomes, the next challenge is to systematically assign functions to all predicted genes in the genome. Functional genome analysis of plants has entered the high-throughput stage. The generations and collections of mutants at the genome-wide level form technological platform of functional genomics. However, to identify the exact function of unknown genes it is necessary to understand each gene's role in the complex orchestration of all gene activities in the plant cell. Gene function analysis therefore necessitates the analysis of temporal and spatial gene expression patterns. The most conclusive information about changes in gene expression levels can be gained from analysis of the varying qualitative and quantitative changes of messenger RNAs, proteins and metabolites. New technologies have been developed to allow fast and highly parallel measurements of these constituents of the cell that make up gene activity. We have reviewed currently employed technologies to identify unknown functions of predicted genes including map-based cloning, insertional mutagenesis, reverse genetics, chemical mutagenesis, microarray analysis, FOX-hunting system, gene silencing mutagenesis, proteomics and chemical genomics. Recent improvements in technologies for functional genomics enable whole-genome functional analysis, and thus open new avenues for studies of the regulations and functions of unknown genes in plants.

Cloning and Characterization of ${\Delta}^1$-Pyrroline-5-Carboxylate Synthetase Genes and Identification of Point Mutants in Medicago truncatula

  • Song, Ki-Hoon;Song, Dae-Hae;Lee, Jeong-Ran;Kim, Goon-Bo;Choi, Hong-Kyu;Penmetsa, R. Varma;Nam, Young-Woo
    • 한국작물학회지
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    • 제52권4호
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    • pp.458-468
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    • 2007
  • To tolerate environmentally adverse conditions such as cold, drought, and salinity, plants often synthesize and accumulate proline in cells as compatible osmolytes. ${\Delta}^1$-Pyrroline-5-carboxylate synthetase(P5CS) catalyzes the rate-limiting step of proline biosynthesis from glutamate. Two complete genes, MtP5CS1 and MtP5CS2, were isolated from the model legume Medicago truncatula by cDNA cloning and bacterial artificial chromosome library screening. Nucleotide sequence analysis showed that both genes consisted of 20 exons and 19 introns. Alignment of the predicted amino acid sequences revealed high similarities with P5CS proteins from other plant species. The two MtP5CS genes were expressed in response to high salt and low temperature treatments. Semi-quantitative reverse transcription-polymerase chain reaction showed that MtP5CS1 was expressed earlier than MtP5CS2, indicating differential regulation of the two genes. To evaluate the reverse genetic effects of nucleotide changes on MtP5CS function, a Targeting Induced Local Lesions in Genomes approach was taken. Three mutants each were isolated for MtP5CS1 and MtP5CS2, of which a P5CS2 nonsense mutant carrying a codon change from arginine to stop was expected to bring translation to premature termination. These provide a valuable genetic resource with which to determine the function of the P5CS genes in environmental stress responses of legume crops.

Impaired Hippocampal Synaptic Plasticity and Enhanced Excitatory Transmission in a Novel Animal Model of Autism Spectrum Disorders with Telomerase Reverse Transcriptase Overexpression

  • Rhee, Jeehae;Park, Kwanghoon;Kim, Ki Chan;Shin, Chan Young;Chung, ChiHye
    • Molecules and Cells
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    • 제41권5호
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    • pp.486-494
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    • 2018
  • Recently, we have reported that animals with telomerase reverse transcriptase (TERT) overexpression exhibit reduced social interaction, decreased preference for novel social interaction and poor nest-building behaviors-symptoms that mirror those observed in human autism spectrum disorders (ASD). Overexpression of TERT also alters the excitatory/inhibitory (E/I) ratio in the medial prefrontal cortex. However, the effects of TERT overexpression on hippocampal-dependent learning and synaptic efficacy have not been investigated. In the present study, we employed electrophysiological approaches in combination with behavioral analysis to examine hippocampal function of TERT transgenic (TERT-tg) mice and FVB controls. We found that TERT overexpression results in enhanced hippocampal excitation with no changes in inhibition and significantly impairs long-term synaptic plasticity. Interestingly, the expression levels of phosphorylated CREB and phosphorylated $CaMKII{\alpha}$ were significantly decreased while the expression level of $CaMKII{\alpha}$ was slightly increased in the hippocampus of TERT-overexpressing mice. Our observations highlight the importance of TERT in normal synaptic function and behavior and provide additional information on a novel animal model of ASD associated with TERT overexpression.

한국 대도시의 도시화 특성 : 이동, 통근자 자료 분석을 통한 도시화 단계의 실증적 검토 (Urbanization of Large Cities in Korea : Assessing Development Stages using Migration and Commuting data)

  • 권상철
    • 한국지역지리학회지
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    • 제17권5호
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    • pp.536-553
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    • 2011
  • 최근 산업도시 성장 이후 탈산업화 시대에 전개되는 새로운 도시화에 대한 논의가 포스트모던 도시, 소비도시 등으로 다양하게 전개된다. 도시화의 단계적 접근에서는 인구 변화와 이동에 기초하여 거대도시는 도시화의 후기 단계인 재도시화를 경험하고 있으며, 이러한 도시화 단계는 시차를 두고 점진적으로 하위 규모 도시에서 나타날 것으로 추정된다. 그러나 산업 재구조화는 인구 규모만으로는 포착되지 않는 새로운 도시화 특성을 유발할 것으로, 본 연구는 한국 대도시의 도시화 특성을 이동, 통근 인구 그리고 이들의 지리적, 사회적 특성에 기초하여 검토하였다. 대도시별 도시화 경험은 다르게 나타나는데, 서울은 단계적 도시화 과정을 거치지만, 다른 대도시들은 산업도시와 탈산업도시로의 전이에서 다양한 모습을 드러낸다. 특히, 지방 대도시의 경우 산업 기반의 교외화가 이루어졌으나 중심 도시의 편리한 주거, 생활 환경으로 중심 도시에 거주하며 주변으로 역통근하는 인구가 늘고 중장년층의 경제활동 가구가 대도시로 유입되며 주거 기능이 새로운 도시의 역할로 확대되는데, 이는 한국 대도시의 새로운 도시화 특성이라 하겠다.

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PLD 소자의 LASAR 부품 모델링을 통한 고장 검출 (Fault Detection through the LASAR Component modeling of PLD Devices)

  • 표대인;홍승범
    • 한국항행학회논문지
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    • 제24권4호
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    • pp.314-321
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    • 2020
  • LASAR (logic automated stimulus and response) 소프트웨어는 디지털 전자 회로 카드에 대한 로직 기능시험 및 고장검출을 위한 자동점검프로그램 개발도구이다. LASAR 소프트웨어는 소자의 논리회로 기능 및 입·출력 정의된 정보가 필요하다. 소자 정보가 없으면 정상적인 부품 모델링이 불가능하다. 따라서 본 논문에서는 소자 정보가 없는 PLD (programmable logic device) 소자를 역설계 방법을 통하여 부품 모델링을 수행한다. 개발된 LASAR 프로그램은 고장 시뮬레이션 결과와 단일 고착 고장삽입 방법을 통해 고장 검출율을 확인하였다. 고장 검출율은 기존의 제한적인 모델링은 91%, 역설계를 통한 모델링은 94%로 3% 상승하였다. 또한, EP 310 PLD 소자에 대한 입·출력핀에 대한 22가지 고착결함의 경우 100% 검출하여 양호한 성능을 확인하였다.

공기 전도형 출력을 갖는 정원창 자극형 인공중이의 출력방식 제안 (A Proposal of Output Method of Round Window Stimulation Type Middle Ear Implants using Acoustic Transmission)

  • 성기웅;이규엽;김명남;조진호
    • 한국멀티미디어학회논문지
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    • 제21권6호
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    • pp.678-684
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    • 2018
  • In order to broaden the indication of middle ear implant, research has been actively conducted on the reverse output method that stimulates the round window. However, it is very difficult to transmit the vibration output effectively because the indivisual anatomical difference of the round window niche is very large and also the visual field is not secured even by a skilled otolaryngologic surgeon. In this paper, we propose a new reverse stimulation method of middle ear implants that transmits energy to the inner ear by using air as a medium. This can compensate for the disadvantages of the conventional method of transmitting vibration energy and minimizes the energy transfer efficiency interference due to the combination of the excitation point and the output device. It was shown that forward and backward transfer characteristics were obtained by cadaveric experiments, and it was shown that it can overcome the acoustical impedance of high round window and transmit energy to inner ear. The receiver, which is the output device of the conventional hearing aids, can generate a constant volume velocity, so it can have a high output at a limited volume, such as a round window niche. So, suggested method can overcome the high acoustical impedance of the round window and deliver acoustic energy to the inner ear.

수동형 UHF RFID 인터페이스에 대한 Link budget의 재해석 및 전파 환경 요소 분석 (Passive UHF RFID Propagation Characteristics and Reconsideration of Link budget on Practical Communication Area)

  • 정진우;박경태;노형환;박준석;김형석
    • 한국정보통신설비학회:학술대회논문집
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    • 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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    • pp.469-472
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    • 2008
  • In this paper, we discuss the recent trends on the passive UHF RFID tag chip design techniques and several important system parameters. We also summarize link budget studies on both conventional and modem UHF RFID communications. The paper highlights the reverse link limited case, which has known to be the minor concern if reader continuous wave (CW) can reach the tag in sufficient level. This makes sense when the tag sensitivity is rather high (over 10-12${\mu}W$); however, since the tag chip fabrication technologies have been developed by time, the tag chip threshold levels are now less-dominant in determining link margin. If the tag limitation can be alleviated, the forward link limited case can be resolved; thus, we rather focus on the path-loss problem. Since the path-losses are still exist in both forward and reverse links, and it can be doubled while CW travels the reader-tag-reader path because forward link and reverse link are on the same distance. Consider if reader receiver sensitivity is very high in the worst case. In this case, weaken tag response (i.e., backscatters) cannot reach the level that reader receiver can process tag data; bit-error rate can be higher. Overall, backscatter levels should be high enough so that reader receiver can correctly function. After discussing link budget, we carried out practical measurements on fading effects between two circularly polarized UHF RFID antennas in a small scale area.

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손상된 역삼투막의 in-situ 힐링을 통한 막 성능 복원 (Restoration of Membrane Performance for Damaged Reverse Osmosis Membranes through in-situ Healing)

  • 윤원섭;임지원;조영주
    • 멤브레인
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    • 제29권2호
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    • pp.96-104
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    • 2019
  • 본 연구는 분리막 성능 저하로 기능을 상실한 역삼투막의 힐링을 통한 복원의 가능성을 알아보고자 하는 데에 목적이 있다. 손상된 막은 양이온고분자인 poly(styrene sulfonic acid) sodium salt (PSSA)와 음이온고분자인 polyethyleneimine(PEI)를 염석법을 이용하여 이중으로 코팅했으며 또한 소재의 순서를 바꿔 코팅을 수행했다. 그리고 농도, 시간, 이온세기 등에 따라 코팅된 역삼투막의 투과도와 배제율을 측정하여 손상된 막으로부터 복원된 정도를 알아보았다. 또한 역삼투 평막에서 복원이 우수한 조건을 가정용 정수기 모듈에 적용하여 손상된 역삼투막 모듈에 또한 대하여 복원 가능성을 알아보았다. 이로부터 PEI 30,000 ppm (IS = 0.1)/PSSA 20,000 ppm (IS = 0.7) 코팅 조건에서 역삼투막 모듈에 적용했을 때 염 배제율은 69%에서 86% (손상 전 모듈의 경우 90%)까지 복원되었다.

실행코드 비교 감정에서 주변장치 분석의 유효성 (Study on the comparison result of Machine code Program)

  • 김도현;이규대
    • 한국소프트웨어감정평가학회 논문지
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    • 제16권1호
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    • pp.37-44
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    • 2020
  • 소프트웨어의 유사성 비교는 소스코드를 대상으로 한다. 소스코드는 프로그램 언어로 표현된 개발자의 지적 저작권으로 보호된다. 문서형식으로 작성된 프로그램 소스코드는 개발자의 전문지식과 아이디어가 포함된 내용을 포함하고 있다. 소프트웨어 저작권의 불법도용을 판단하기 위한 감정 작업은 원본과 비교본의 소스 코드를 대상으로 파일의 구성과 내용을 검증하는 방법으로 수행된다. 그러나 실제적으로 피고소인 측의 불성실한 목적물 제공으로 소스코드의 일대일 비교감정이 어려운 상황이 증가하고 있다. 이 경우 실행코드에 대한 비교감정이 수행되어야 하며, 역어셈블 방법, 역공학기법, 기능실행의 시퀀스 분석 등의 간접적인 방법이 적용된다. 본 논문에서는 소스코드제공이 어려운 상황에서 시스템과 실행코드 파일을 대상하는 하는 감정 사례를 통해 간접적인 비교결과의 유효성에 대해 분석하고, 감정결과에 활용하는 방안을 제시한다.

패턴형 이온교환막을 이용한 스택의 셀 수 및 크기에 따른 역전기투석 성능 평가 (Evaluation of Reverse Electrodialysis based on the Number of Cell Pairs and Stack Size Using Patterned Ion Exchange Membrane)

  • 이동건;김한기;정남조;목영선;최지연
    • 신재생에너지
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    • 제19권2호
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    • pp.31-39
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    • 2023
  • Salinity gradient energy can be generated from a mixture of water streams with different salt concentrations by using reverse electrodialysis (RED). In this study, we evaluated the effect of stack size and number of cell pairs on the energy efficiency and specific energy of the RED process. Additionally, we studied the prementioned parameters to maximize the power density of RED. The performance of the RED stack which used a patterned ion exchange membrane, was evaluated as a function of stack size and feed flow rate. Moreover, it was noted that an increase in stack size increased the ion movement through the ion exchange membrane. Furthermore, an increase in feed flow rate led to a reduction in the concentration variation, resulting in an increase in OCV and power density. The energy efficiency and specific energy for 100 cells in the 10 × 10 cm2 stack were the highest at 12% and 0.05 kWh/m3, respectively, while the power density from 0.33 cm/s to 5 × 5 cm2 stack was the highest at 0.53 W/m2. The study showed that the RED performance can be improved by altering the size of the stack and the number of cell pairs, thereby positively affecting energy efficiency and specific energy.