• Title/Summary/Keyword: Challenge-response

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Responses of Arabidopsis thaliana to Challenge by Pseudomonas syringae

  • Kim, Min Gab;Kim, Sun Young;Kim, Woe Yeon;Mackey, David;Lee, Sang Yeol
    • Molecules and Cells
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    • v.25 no.3
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    • pp.323-331
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    • 2008
  • Plants are continually exposed to a variety of potentially pathogenic microbes, and the interactions between plants and pathogenic invaders determine the outcome, disease or disease resistance. To defend themselves, plants have developed a sophisticated immune system. Unlike animals, however, they do not have specialized immune cells and, thus all plant cells appear to have the innate ability to recognize pathogens and turn on an appropriate defense response. Using genetic, genomic and biochemical methods, tremendous advances have been made in understanding how plants recognize pathogens and mount effective defenses. The primary immune response is induced by microbe-associated molecular patterns (MAMPs). MAMP receptors recognize the presence of probable pathogens and evoke defense. In the co-evolution of plant-microbe interactions, pathogens gained the ability to make and deliver effector proteins to suppress MAMP-induced defense responses. In response to effector proteins, plants acquired R-proteins to directly or indirectly monitor the presence of effector proteins and activate an effective defense response. In this review we will describe and discuss the plant immune responses induced by two types of elicitors, PAMPs and effector proteins.

Enhancement of Anti-tumor Immunity by Administration of Macrolepiota procera Extracts (큰갓버섯 추출물의 종양면역 증진 효과)

  • Han, Kyung-Hoon;Kim, Doh-Hee;Song, Kwan-Yong;Lee, Kye-Heui;Kang, Tae-Bong;Yoon, Taek-Joon
    • Korean Journal of Pharmacognosy
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    • v.43 no.1
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    • pp.32-38
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    • 2012
  • To examine the potentiation of Macrolepiota procera extracts (MPE-4) to act as adjuvant enhancing the tumor specific anti-tumor immune response, tumor vaccine prepared by boiling (HK vaccine) admixed with MPE-4 and immunized in mice. Vaccination of mice with HK vaccine in combination with MPE-4 resulted in higher inhibition in tumor metastasis compared with the mice of HK vaccine alone treatment against live syngeneic tumor cell challenge. The splenocytes from mice immunized HK vaccine mixed with MPE-4 was able to elicit a stronger cytotoxic T lymphocyte (CTL) response as compared with HK vaccine alone. In addition, the splenocytes from MPE-4 admixed HK vaccine immunized mice secreted a higher concentration of Th1 type cytokine such as IFN-${\gamma}$, and GM-CSF. Furthermore, the adoptive transfer of splenocytes from mice immunized HK vaccine and MPE-4 led to a more robust anti-tumour response than the HK vaccine alone. Overall, these results indicate that MPE-4 is a good candidate adjuvant of anti-tumor immune response.

Performance Improvement of Acoustic Echo Cancellers Using Delayless Subband Adaptive Filters And Fast Affine Projection Algorithm

  • Ahn, Kyung-Seung
    • The Journal of the Acoustical Society of Korea
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    • v.17 no.2E
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    • pp.3-9
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    • 1998
  • Since the introduction of hands-free phone set and teleconferencing system, acoustic echo cancellation has been a challenge for engineers. Recently many researches have shown that the best solution for the acoustic echo compensation problem is represented by an adaptive filter which iteratively tries to identify the unknown impulse response of the system from loudspeaker to microphone. In this paper, we apply the delayless subband adaptive filters and fast affine projection algorithm for the identification of room impulse response. Simulation results show 3∼8 dB more enhanced performance than conventional fullband adaptive filters or subband adaptive filters. In addition, fast affine projection algorithm shows better convergence speed at the expense of the low computational complexity than conventional LMS algorithm.

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IL-33 Priming Enhances Peritoneal Macrophage Activity in Response to Candida albicans

  • Tran, Vuvi G.;Cho, Hong R.;Kwon, Byungsuk
    • IMMUNE NETWORK
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    • v.14 no.4
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    • pp.201-206
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    • 2014
  • IL-33 is a member of the IL-1 cytokine family and plays a role in the host defense against bacteria, viruses, and fungi. In this study, we investigated the function of IL-33 and its receptor in in vitro macrophage responses to Candida albicans. Our results demonstrate that pre-sensitization of isolated peritoneal macrophages with IL-33 enhanced their pro-inflammatory cytokine production and phagocytic activity in response to C. albicans. These macrophage activities were entirely dependent on the ST2-MyD88 signaling pathway. In addition, pre-sensitization with IL-33 also increased ROS production and the subsequent killing ability of macrophages following C. albicans challenge. These results indicate that IL-33 may increase anti-fungal activity against Candida through macrophage-mediated resistance mechanisms.

Alanine Aminotransferase in Amphioxus: Presence, Localization and Up-regulation after Acute Lipopolysaccharide Exposure

  • Lun, Li-Min;Zhang, Shi-Cui;Liang, Yu-Jun
    • BMB Reports
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    • v.39 no.5
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    • pp.511-515
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    • 2006
  • Alanine aminotransferase (AAT) is mainly synthesized in the liver, and its level in mammalian serum is elevated after acute phase induction. Here we demonstrated that sheep anti-human AAT antibody cross-reacted with amphioxus humoral fluids as well as human serum; and the concentration of AAT in the humoral fluids in amphioxus increased after the acute challenge with lipopolysaccharide, while the level of total proteins remains unchanged. These suggest the presence of the same acute phase response pattern in amphioxus, as observed in some mammalian species. Immunohistochemically, AAT was localized in the hepatic diverticulum, ovary and testis. It appears that the hepatic diverticulum in amphioxus is functionally homologous to the vertebrate liver in respect of AAT synthesis, supporting the hypothesis that the vertebrate liver evolved from the hepatic diverticulum of an amphioxus-like ancestor during early chordate evolution.

Numerical simulation of shaking table tests on 3D reinforced concrete structures

  • Bayhan, Beyhan
    • Structural Engineering and Mechanics
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    • v.48 no.2
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    • pp.151-171
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    • 2013
  • The current paper presents the numerical blind prediction of nonlinear seismic response of two full-scale, three dimensional, one-story reinforced concrete structures subjected to bidirectional earthquake simulations on shaking table. Simulations were carried out at the laboratories of LNEC (Laboratorio Nacional de Engenharia Civil) in Lisbon, Portugal. The study was motivated by participation in the blind prediction contest of shaking table tests, organized by the challenge committee of the 15th World Conference on Earthquake Engineering. The test specimens, geometrically identical, designed for low and high ductility levels, were subjected to subsequent earthquake motions of increasing intensity. Three dimensional nonlinear analytical models were implemented and subjected to the input base motions. Reasonably accurate reproduction of the measured displacement response was obtained through appropriate modeling. The goodness of fit between analytical and measured results depended on the details of the analytical models.

Dynamic Shock Simulation of Head-gimbal Assembly in Micro MO Drives (초소형 광자기 드라이브용 HGA의 동적 충격 시뮬레이션)

  • 오우석;홍어진;박노철;양현석;박영필
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.189-194
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    • 2004
  • As a disk drive becomes widely used in portable environments, one of the important requirements is durability under severe environmental condition, especially, resistance to mechanical shock. An important challenge in the disk recording is to improve disk drive robustness in shock environments. If the system comes In contact with outer shock disturbance, the system gets critical damage in head-gimbal assembly or disk. This paper describes analysis of a HGA(head-gimbal assembly) in micro MO drives to shock loading during both non-operating state and operating state. A finite element model which consists of the disk, suspension, slider and air bearing was used to find structural response of micro MO drives. In the operational case. the air bearing is approximated with four linear elastic springs. The commercially available finite element solver, ANSYS/LS-DYNA, is used to simulate the shock response of the HGA in micro MO drives. In this paper, the mechanical robustness of the suspension is simuiated considering the shock responses of the HGA.

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EDISON Co-rotational Plane beam-Dynamic tip load를 이용한 가진주파수 변화에 따른 외팔보의 자유단 진동 연구

  • Park, Cheol-U;Ju, Hyeon-Sik
    • Proceeding of EDISON Challenge
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    • 2015.03a
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    • pp.246-250
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    • 2015
  • In this paper, Timoshenko and Euler-Bernoulli beam theories(EB-beam) are used, and Fast Fourier Transformation(FFT) analysis is then employed to extract their natural frequencies using both analytical approach and Co-rotational plane beam(CR-beam) EDISON program. EB-beam is used to analyze a spring-mass system with a single degree of freedom. Sinusoidal force with various frequencies and constant magnitude are applied to tip of each beam. After the oscillatory tip response is observed in EB-beam, it decreases and finally converges to the so-called 'steady-state.' The decreasing rate of the tip deflection with respect to time is reduced when the forcing frequency is increased. Although the tip deflection is found to be independent of the excitation frequency, it turns out that time to reach the steady state response is dependent on the forcing frequency.

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Enhancing Gas Response Characteristics of Mixed Metal Oxide Gas Sensors

  • Balamurugan, Chandran;Song, Sun-Ju;Kim, Ho-Sung
    • Journal of the Korean Ceramic Society
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    • v.55 no.1
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    • pp.1-20
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    • 2018
  • Semiconducting nanomaterials have attracted considerable interest in recent years due to their high sensitivity, selectivity, and fast response time. In addition, for portable applications, they have low power consumption, lightweight, simple in operation, a low maintenance cost. Furthermore, it is easy to manufacture microelectronic sensor structures with metallic oxide sensitive thin layers. The use of semiconducting metal oxides to develop highly sensitive chemiresistive sensing systems remains an important scientific challenge in the field of gas sensing. According to the sensing mechanisms of gas sensors, the overall sensor conductance is determined by surface reactions and the charge transfer processes between the adsorbed species and the sensing material. The primary goal of the present study is to explore the possibility of using semiconducting mixed metal oxide nanostructure as a potential sensor material for selective gases.

Quality Adaptation of Intra-only Coded Video Transmission over Wireless Networks

  • Shu Tang;Yuanhong Deng;Peng Yang
    • Journal of Information Processing Systems
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    • v.19 no.6
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    • pp.817-829
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    • 2023
  • Variable wireless channel is a big challenge for real-time video applications, and the rate adaptation of realtime video streaming becomes a hot topic. Intra-video coding is important for high-quality video communication and industrial video applications. In this paper, we proposed a novel adaptive scheme for real-time video transmission with intra-only coding over a wireless network. The key idea of this scheme is to estimate the instantaneous remaining capacity of the network to adjust the quality of the next several video frames, which not only can keep low queuing delay and ensure video quality, but also can respond to bandwidth changes quickly. We compare our scheme with three different schemes in the video transmission system. The experimental results show that our scheme has higher bandwidth utilization and faster bandwidth change response, while maintaining low queuing delay.