• Title/Summary/Keyword: Adaptive response

Search Result 903, Processing Time 0.026 seconds

Regulation of Abiotic Stress Response by Alternative Splicing in Plants (식물에서 선택적 스플라이싱에 의한 스트레스 반응 조절)

  • Seok, Hye-Yeon;Lee, Sun-Young;Moon, Yong-Hwan
    • Journal of Life Science
    • /
    • v.30 no.6
    • /
    • pp.570-579
    • /
    • 2020
  • Pre-mRNA splicing is a crucial step for the expression of information encoded in eukaryotic genomes. Alternative splicing occurs when splice sites are differentially recognized and more than one transcript and potentially multiple proteins are generated from the same pre-mRNA. The decision on which splice sites are selected under particular cellular conditions is determined by the interaction of proteins, globally designated as splicing factors, that guide spliceosomal components, and thereby the spliceosome, to their respective splice sites. Abiotic stresses such as heat, cold, salt, drought, and hypoxia markedly alter alternative splicing patterns in plants, and these splicing events implement changes in gene expression for adaptive responses to adverse environments. Alteration of the expression or activity of splicing factors results in alternative splicing under cold, heat, salt, or drought conditions, and alternatively spliced isoforms respond distinctly in several aspects such as expression in different tissues or degradation via nonsense-mediated decay. Spliced isoforms may vary in their subcellular localization or have different biological functions under stress conditions. Despite numerous studies, functional analyses of alternative splicing have been limited to particular abiotic stresses; the molecular mechanism of alternative splicing in abiotic stress response remains uncovered which suggests that further studies are needed in this area.

Dual BTC Image Coding technique for Full HD Display Driver (Full HD 디스플레이 드라이버를 위한 Dual BTC 영상부호화 기법)

  • Kim, Jin-Hyung;Ko, Yun-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.49 no.4
    • /
    • pp.1-9
    • /
    • 2012
  • LCD(Liquid Crystal Display) commonly used as an output device has a drawback of slow response time compared with CRT display. This drawback causes motion blur especially when an abrupt intensity change occurs in an image sequence as time goes on. To overcome the problem of slow response time overdriving technique has been used in TCON of LCD. In this technique, the previous frame data has to be compressed and stored in an external memory. Considering both chip size of TCON and computational complexity, AM-BTC has been applied to the 8bit HD display driver. However, the conventional method is not suitable for 10 bit Full HD because 10 bit Full HD data is much larger than that of 8 bit HD data. Being applied to 10 bit Full HD display driver, the conventional method increase cost by enlarging the external memory size of TCON or deteriorates image quality. In this paper, we propose dual BTC image coding technique for Full HD display driver that is an adaptive coding scheme according to morphological information of each sample block. Through experiments, it is verified that the proposed Dual BTC method performs better than the conventional method not only quantitatively but also qualitatively.

Protective Effect of Pesticide on Radiation-Induced Cell Damage in Tradescantia 4430 Stamen Hairs (자주달개비 수술털에서 방사선에 의해 유발되는 세포손상에 대한 살충제의 방어효과)

  • 김진규;김원록;이창주;장화형;이영근
    • Korean Journal of Environmental Biology
    • /
    • v.17 no.1
    • /
    • pp.21-26
    • /
    • 1999
  • To investigate the combined effect of radiation and pesticide on Tradescantia somatic cell mutations, potted plants of Tradescantia 4430 on which parathion had been sprayed evenly 24 hours before irradiation. Radiation doses were 0.3, 0.5, 1.0 and 2.0 Gy of gamma-ray. The plants irradiated only with the gamma-ray radiation were used as control groups (CT). Pink mutation frequency increased linearly proportional to the radiation dose and the peak interval of elevated mutation frequencies appeared during 7 ~ 11 days after irradiation in both CT and Pa +${\gamma}$ groups. The slope of dose -response curve in CT was 5.99 ($r^2$= 0.988), while it was 3.43 (r$x^-2$=0.981) in Pa+${\gamma}$. It seemed that parathion pretreatment had a protective effect against radiation-induced cell damages since it decreased the slope value by 43%. It is suggested that an adaptive response or radiomodification could be induced in irradiated stamen hair cells by parathion pretreatment.

  • PDF

Digitalization of the Nuclear Steam Generator Level Control System (증기발생기 수위조절 시스템의 디지탈화)

  • Lee, Yoon-Joon;Lee, Un-Chul
    • Nuclear Engineering and Technology
    • /
    • v.25 no.1
    • /
    • pp.125-135
    • /
    • 1993
  • The safe and efficient operation of nuclear plants is recognized to be accomplished through the application of plant automation using digital technology, which is one of main targets of the next generation nuclear plants. For plant level automation, it is first required that each major subsystem be digitalized, and the steam generator water level control system is discussed in this study. The transfer functions between inputs and the level are derived by employing the thermal hydraulic model of the steam generator and are applied to the analysis of the current three-element control system. Since the control scheme in this study includes the steam generator itself as a process plant, the system order is high and the numerical instability arises in digitalizing. Together with this, the unreliability of the feedwater feedback signal at low power level leads to the proposal of a two-element control system with a proper digital controller. The digital PI controller developed for this system has the initial power adaptive gain and integration time constant. And it makes the overall system response satisfy the stability and other necessary control specifications simultaneously. Since the two-element control system using this controller depends on the initial power only, it is simple to define and it shows a similar level response behavior to that of its corresponding analog system.

  • PDF

Ginseng berry polysaccharides on inflammation-associated colon cancer: inhibiting T-cell differentiation, promoting apoptosis, and enhancing the effects of 5-fluorouracil

  • Wang, Chong-Zhi;Hou, Lifei;Wan, Jin-Yi;Yao, Haiqiang;Yuan, Jinbin;Zeng, Jinxiang;Park, Chan Woong;Kim, Su Hwan;Seo, Dae Bang;Shin, Kwang-Soon;Zhang, Chun-Feng;Chen, Lina;Zhang, Qi-Hui;Liu, Zhi;Sava-Segal, Clara;Yuan, Chun-Su
    • Journal of Ginseng Research
    • /
    • v.44 no.2
    • /
    • pp.282-290
    • /
    • 2020
  • Background: Ginseng is a commonly used herbal medicine in treating various medical conditions. Chronic gut inflammation is a recognized factor for the development of colorectal cancer (CRC). In this project, Asian ginseng berry polysaccharide preparations were used to assess their effects on CRC and related immune regulation mechanisms. Methods: Ginseng berry polysaccharide extract (GBPE) and purified ginseng berry polysaccharide portion (GBPP) were used to evaluate their activities on human HCT-116 and HT-29 CRC cell proliferation. Interleukin-8 secretion analysis was performed on HT-29 cells. Naive CD4 cell isolation and T-helper cell differentiation were performed and determined using flow cytometry for Th1 and Treg in addition to cell cycle and apoptotic investigation. Results: GBPE and GBPP significantly inhibited interleukin-8 secretion and cancer cell proliferation, inhibited CD4+IFN-γ+ cell (Th1) differentiation, and decreased CD4+FoxP3+ cell (Treg) differentiation. Compared to the GBPE, GBPP showed more potent antiinflammatory activities on the malignant cells. This is consistent with the observation that GBPP can also inhibit Th1-cell differentiation better, suggesting that it has an important role in antiinflammation, whereas Treg cells hinder the body's immune response against malignancies. Supported by cell cycle and apoptosis data, GBPE and GBPP, at various degrees, remarkably enhanced the anticancer activities of 5-fluorouracil. Conclusion: Data from this project suggested that Asian ginseng berry potentially has clinical utility in managing enteric inflammation and suppressing CRC through immunomodulation mechanisms.

Implementation of a Jitter and Glitch Removing Circuit for UHF RFID System Based on ISO/IEC 18000-6C Standard (UHF대역 RFID 수신단(리더)의 지터(비트동기) 및 글리치 제거회로 설계)

  • Kim, Sang-Hoon;Lee, Yong-Joo;Sim, Jae-Hee;Lee, Yong-Surk
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.32 no.1A
    • /
    • pp.83-90
    • /
    • 2007
  • In this paper, we propose an implementation and an algorithm of 'Jitter and Glitch Removing Circuit' for UHF RFID reader system based on ISO/IEC 18000-6C standard. We analyze the response of TI(Texas Instrument) Gen2 tag with a reader using the proposed algorithm. In ISO/IEC 18000-6C standard, a bit rate accuracy(tolerance) is up to +/-22% during tag-to-interrogator communication and +/-1% during interrogator-to-tag communication. In order to solve tolerance problems, we implement the Jitter and Glitch Removing Circuit using the concept of tolerance and tolerance-accumulation instead of PLL(DPLL, ADPLL). The main clock is 19.2MHz and the LF(Link Frequency) is determined as 40kHz to meet the local radio regulation in korea. As a result of simulations, the error-rate is zero within 15% tolerance of tag responses. And in the case of using the adaptive LF generation circuit, the error-rate varies from 0.000589 to zero between 15% and 22% tolerance of tag responses. In conclusion, the error-rate is zero between 0%-22% tolerance of tag response specified in ISO/IEC 18000-6C standard.

Designing fuzzy systems for optimal parameters of TMDs to reduce seismic response of tall buildings

  • Ramezani, Meysam;Bathaei, Akbar;Zahrai, Seyed Mehdi
    • Smart Structures and Systems
    • /
    • v.20 no.1
    • /
    • pp.61-74
    • /
    • 2017
  • One of the most reliable and simplest tools for structural vibration control in civil engineering is Tuned Mass Damper, TMD. Provided that the frequency and damping parameters of these dampers are tuned appropriately, they can reduce the vibrations of the structure through their generated inertia forces, as they vibrate continuously. To achieve the optimal parameters of TMD, many different methods have been provided so far. In old approaches, some formulas have been offered based on simplifying models and their applied loadings while novel procedures need to model structures completely in order to obtain TMD parameters. In this paper, with regard to the nonlinear decision-making of fuzzy systems and their enough ability to cope with different unreliability, a method is proposed. Furthermore, by taking advantage of both old and new methods a fuzzy system is designed to be operational and reduce uncertainties related to models and applied loads. To design fuzzy system, it is required to gain data on structures and optimum parameters of TMDs corresponding to these structures. This information is obtained through modeling MDOF systems with various numbers of stories subjected to far and near field earthquakes. The design of the fuzzy systems is performed by three methods: look-up table, the data space grid-partitioning, and clustering. After that, rule weights of Mamdani fuzzy system using the look-up table are optimized through genetic algorithm and rule weights of Sugeno fuzzy system designed based on grid-partitioning methods and clustering data are optimized through ANFIS (Adaptive Neuro-Fuzzy Inference System). By comparing these methods, it is observed that the fuzzy system technique based on data clustering has an efficient function to predict the optimal parameters of TMDs. In this method, average of errors in estimating frequency and damping ratio is close to zero. Also, standard deviation of frequency errors and damping ratio errors decrease by 78% and 4.1% respectively in comparison with the look-up table method. While, this reductions compared to the grid partitioning method are 2.2% and 1.8% respectively. In this research, TMD parameters are estimated for a 15-degree of freedom structure based on designed fuzzy system and are compared to parameters obtained from the genetic algorithm and empirical relations. The progress up to 1.9% and 2% under far-field earthquakes and 0.4% and 2.2% under near-field earthquakes is obtained in decreasing respectively roof maximum displacement and its RMS ratio through fuzzy system method compared to those obtained by empirical relations.

Effects of Short-term Acute Heat Stress on Physiological Responses and Heat Shock Proteins of Hanwoo Steer (Korean Cattle)

  • Baek, Youl-Chang;Kim, Minseok;Jeong, Jin-Young;Oh, Young-Kyoon;Lee, Sung-Dae;Lee, Yoo-Kyung;Ji, Sang-Yun;Choi, Hyuck
    • Journal of Animal Reproduction and Biotechnology
    • /
    • v.34 no.3
    • /
    • pp.173-182
    • /
    • 2019
  • This study was performed to evaluate the effect of heat stress on the status of physiological responses, blood parameter, serum T3 and cortisol, and heat shock proteins (HSP 27, 70, and 90) of Hanwoo cattle. Six Hanwoo steers (242.8 ± 7.2 kg of BW) were housed in the climate-controlled respiration chambers. The experiment consisted of 7 days (control; 0 day) at thermoneutral (air temperature (Ta) of 15℃ and relative humidity (RH) of 60%; temperature-humidity index (THI) = 64), and by 3 and 6 days (treatment groups) at heat stress (Ta of 35℃ and RH of 60%; THI = 87). Body temperature of each parts (frank, rump, perineum and foot) and rectal temperature elevated in heat stress groups (3 days and 6 days) than the control group (0 day). Respiration rates increased in 3 days and 6 days (88.5 ± 0.96 bpm and 86.3 ± 0.63 bpm, respectively) from 0 days (39.5 ± 0.65 bpm). Feed intake significantly decreased in heat stress groups (3 days and 6 days, 3.7 ± 0.14 kg and 4.0 ± 0.15 kg, respectively) than the control group (0 day, 5.0 ± 0.00 kg). In addition, final BW significantly decreased in heat stress groups (3 days and 6 days, 211.8 ± 4.75 kg and 215.5 ± 3.50 kg, respectively) than the control group (0 day, 240.0 ± 25.00 kg). However, heat stress has no significant effect on blood parameter, serum T3 and cortisol. Nevertheless, heat stress increased HSPs mRNA expression in liver tissue, and serum concentration of HSPs. Despite Hanwoo cattle may have high adaptive ability to heat stress, our results suggested that heat stress directly effect on body temperature and respiration rate as well as serum and tissue HSPs. Therefore, we are recommended that HSPs could be the most appropriate indicators of Hanwoo cattle response to heat stress.

Orientia tsutsugamushi Infection Induces $CD4^+$ T Cell Activation via Human Dendritic Cell Activity

  • Chu, Hyuk;Park, Sung-Moo;Cheon, In Su;Park, Mi-Yeoun;Shim, Byoung-Shik;Gil, Byoung-Cheol;Jeung, Woon Hee;Hwang, Kyu-Jam;Song, Ki-Duk;Hong, Kee-Jong;Song, Manki;Jeong, Hang-Jin;Han, Seung Hyun;Yun, Cheol-Heui
    • Journal of Microbiology and Biotechnology
    • /
    • v.23 no.8
    • /
    • pp.1159-1166
    • /
    • 2013
  • Orientia tsutsugamushi, a gram-negative bacterium, causes severe acute febrile illness in humans. Despite this danger, the route of infection, infectivity, and protective mechanisms of the host's immune response to O. tsutsugamushi are unclear. Dendritic cells (DCs) are one of the most important cell types in bridging the innate and adaptive immune responses. In this study, we observed that O. tsutsugamushi infects and replicates in monocyte-derived DCs (MODCs). During infection and replication, the expressions of the cytokines IL-12 and TNF-${\alpha}$, as well as the co-stimulatory molecules CD80, CD83, CD86, and CD40, were increased in MODCs. When O. tsutsugamushi-treated MODCs were co-cultured with autologous $CD4^+$ T cells, they enhanced production of IFN-${\gamma}$, a major Th1 cytokine. Collectively, our results show that O. tsutsugamushi can replicate in MODCs and can simultaneously induce MODC maturation and increase proinflammatory cytokine levels in MODCs that subsequently activate $CD4^+$ T cells.

Implementation of the Agent using Universal On-line Q-learning by Balancing Exploration and Exploitation in Reinforcement Learning (강화 학습에서의 탐색과 이용의 균형을 통한 범용적 온라인 Q-학습이 적용된 에이전트의 구현)

  • 박찬건;양성봉
    • Journal of KIISE:Software and Applications
    • /
    • v.30 no.7_8
    • /
    • pp.672-680
    • /
    • 2003
  • A shopbot is a software agent whose goal is to maximize buyer´s satisfaction through automatically gathering the price and quality information of goods as well as the services from on-line sellers. In the response to shopbots´ activities, sellers on the Internet need the agents called pricebots that can help them maximize their own profits. In this paper we adopts Q-learning, one of the model-free reinforcement learning methods as a price-setting algorithm of pricebots. A Q-learned agent increases profitability and eliminates the cyclic price wars when compared with the agents using the myoptimal (myopically optimal) pricing strategy Q-teaming needs to select a sequence of state-action fairs for the convergence of Q-teaming. When the uniform random method in selecting state-action pairs is used, the number of accesses to the Q-tables to obtain the optimal Q-values is quite large. Therefore, it is not appropriate for universal on-line learning in a real world environment. This phenomenon occurs because the uniform random selection reflects the uncertainty of exploitation for the optimal policy. In this paper, we propose a Mixed Nonstationary Policy (MNP), which consists of both the auxiliary Markov process and the original Markov process. MNP tries to keep balance of exploration and exploitation in reinforcement learning. Our experiment results show that the Q-learning agent using MNP converges to the optimal Q-values about 2.6 time faster than the uniform random selection on the average.