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Dihydroceramide was Highly Elevated by the Fumonisin B1 and Desipramine in Sphingomonas chungbukensis

  • Burenjargal, Munkhtsatsral;Lee, Youn-Sun;Yoo, Jae-Myung;Choi, Mi-Hwa;Ji, So-Young;Lee, Yong-Moon;Kim, Young-Chang;Oh, Sei-Kwan;Yun, Yeo-Pyo;Yoo, Hwan-Soo
    • Biomolecules & Therapeutics
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    • v.16 no.2
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    • pp.100-105
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    • 2008
  • The sphingolipid metabolites act as lipid mediator for cell proliferation and apoptosis in mammalian cells. In bacteria, sphingolipid metabolism remains unknown. The purpose of this study was to investigate whether sphingolipid metabolism is potential target for fumonisin $B_1$($FB_1$) and desipramine in Sphingomonas chungbukensis, Gram-negative bacteria, by comparing the intracellular contents of bacterial sphingolipids with ones of HIT-T15 ${\beta}$-cells, hamster pancreatic cells. The concentrations of ceramide and dihydroceramide were 18.0 ${\pm}$ 12.0 and 0.025 ${\pm}$ 0.018 nmol/mg protein, respectively, in HIT-T15 cells. However, the concentrations of ceramide and dihydroceramide in the bacterial culture were 2.0 ${\pm}$ 1.2 and 10.6 ${\pm}$ 5.5 nmol/mg protein, respectively. $FB_1$ decreased the level of ceramide from 18.0 to 3.8 nmol/mg protein in HIT-T15 ${\beta}$-cells. However, dihydroceramide content in $FB_1$-treated HIT-T15 cells was slightly decreased compared with the control culture. When S. chungbukensis was treated with either $FB_1$ or desipramine, dihydroceramide level was increased by 5- and 4-fold, respectively, compared with the control bacteria. These results indicate that $FB_1$ and desipramine may act as an activator in bacterial sphingolipid biosynthetic pathway, and bacterial sphingolipid metabolism pathway appears to be different from the pathway of mammalian cells.

Research on Event Mechanism for Reducing Power Overheads in Cache Memory Synchronization (캐시 메모리 동기화 전력 감소를 위한 이벤트 메커니즘에 대한 연구)

  • Pak, Young-Jin;Jeong, Ha-Young;Lee, Yong-Surk
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.48 no.3
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    • pp.69-75
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    • 2011
  • In this paper, we propose an anycast event driven synchronization mechanism to reduce power overheads. Our proposed mechanism can reduce unnecessary polling operations on SHI(Snoop Hit Invalidate) or SHR(Snoop Hit Read) states. It prevents waisting bandwidth and reduces power overheads on polling operation. Also it decreases transition power of state change compared to broadcast model. Simulation results indicated that the proposed architecture had about 15.3% of power decrease compared to spin-lock model and about 4.7% of power decrease compared to broadcast model. Overall results indicated that proposed synchronization mechanism could increase power efficiency of multi-core system by reducing power overheads.

Design of Push Agent Model Using Dual Cache for Increasing Hit-Ratio of Data Search (데이터 검색의 적중률 향상을 위한 이중 캐시의 푸시 에이전트 모델 설계)

  • Kim Kwang-jong;Ko Hyun;Kim Young-ja;Lee Yon-sik
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.6 s.38
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    • pp.153-166
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    • 2005
  • Existing single cache structure has shown difference of hit-ratio according to individually replacement strategy However. It needs new improved cache structure for reducing network traffic and providing advanced hit-ratio. Therefore, this Paper design push agent model using dual cache for increasing hit-ratio by reducing server overload and network traffic by repetition request of persistent and identical information. In this model proposes dual cache structure to do achievement replace gradual cache using by two caches storage space for reducing server overload and network traffic. Also, we show new cache replace techniques and algorithms which executes data update and delete based on replace strategy of Log(Size) +LRU, LFU and PLC for effectiveness of data search in cache. And through an experiment, it evaluates Performance of dual cache push agent model.

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HIT PV Module Performance Research for an Improvement of Long-term Reliability: A Review

  • Park, Hyeong Sik;Jeong, Jae-Seong;Park, Chang Kyun;Lim, Kyung Jin;Shin, Won Seok;Kim, Yong Jun;Kang, Jun Young;Kim, Young Kuk;Park, No Chang;Nam, Sang-Hun;Boo, Jin-Hyo;Yi, Junsin
    • Current Photovoltaic Research
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    • v.5 no.2
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    • pp.47-54
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    • 2017
  • We report finding ways to improve the long-term reliability of PV module including the heterostructure with the intrinsic thin layer (HIT) solar cell. We point out the stability of the products of Panasonic HIT cell. We account for a brief description of the module manufacturing process to investigate the issues of each process and analyze the causes. We carried out the silicon PV module of the glass to glass type under the damp heat test around 1000 hours. However, it degraded around 7% of PV module power after 300 hours exposure in comparison with the initial status (Initial: 12.7 Watt). We investigated possible cause and solutions for the module performance to develop the long-term reliability.

Fuzzy Relevance-based Transcoding for Differentiated Streaming Media Service in the Proxy System (프록시 시스템에서 차별화된 스트리밍 미디어 서비스를 위한 퍼지 적합도 기반 트랜스 코딩)

  • Lee, Chong-Deuk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.6
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    • pp.2785-2792
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    • 2011
  • Such problems as delay, congestion, and crosstalk in the proxy system degrade not only QoS (Quality of Service) but responsiveness and reliability of the streaming media service. To solve this problem this paper proposed a FRTP (Fuzzy Relevance-based Transcoding Proxy) mechanism. The proposed FRTP mechanism analyzes fuzzy similarity for partitioned segment versions of media objects to create a FRTG (Fuzzy Relevance-based Transcoding Graph). Created FRTG determines the transcoding for partitioned media object segment versions. Determined transcoding improves DSR (Delay Saving Ratios), CHPR (Cache Hit Precision Ratio), and CHRR (Cache Hit Recall Ratio). The proposed mechanism is simulated to evaluate such performance parameters as DSR, CHPR, and CHRR. Simulation results shows that the proposed mechanism outperforms in DSR, CHPR and CHRR compared with the other existing mechanisms.

A Genetically Engineered Pseudomonas fluorescens Strain Possesses Dual Activity Against Phytopathogenic Fungi and Insects

  • Lu, Wenwei;Zhang, Weiqiong;Bai, Yan;Fu, Yingying;Chen, Jun;Geng, Xiaolu;Wang, Yujing;Xiao, Ming
    • Journal of Microbiology and Biotechnology
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    • v.20 no.2
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    • pp.281-286
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    • 2010
  • A Pseudomonas fluorescens strain was isolated and found to show antagonistic activity against phytopathogenic fungi and to possess a gene responsible for production of antibiotic 2,4-diacetylphloroglucinol. For the extension of biocontrol range, a gene for an Androetonus australis Hector insect toxin 1 (AaHIT1), one of the most known toxic insect-selective peptides, was designed and synthesized according to the preferred codon usage of Pseudomonas fluorescens, cloned, and transformed into the strain by pSUP106 vector, a broad-host-range plasmid. Bioassays indicated that the engineered strain was able to produce AaHIT1 with insecticidal activity, and at the same time retain the activity against plant pathogen. The experiments for nonplanted soil and rhizosphere colonization showed that, similar to the population of the wild-type strain, that of the engineered strain remained relatively constant in the first 10 days, and the subsequent 50 days, suggesting that AaHIT1 expression in the bacterial cell does not substantially impair its long-term colonization. It is first reported that a Pseudomonas fluorescens strain expressing an active scorpion neurotoxin has dual activity against phytopathogenic fungi and insects, making at attractive for agronomic applications.

Hot Spot Prediction Method for Improving the Performance of Consistent Hashing Shared Web Caching System (컨시스턴스 해슁을 이용한 분산 웹 캐싱 시스템의 성능 향상을 위한 Hot Spot 예측 방법)

  • 정성칠;정길도
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.5B
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    • pp.498-507
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    • 2004
  • The fast and Precise service for the users request is the most important in the World Wide Web. However, the lest service is difficult due to the rapid increase of the Internet users recently. The Shared Web Caching (SWC) is one of the methods solving this problem. The performance of SWC is highly depend on the hit rate and the hit rate is effected by the memory size, processing speed of the server, load balancing and so on. The conventional load balancing is usually based on the state history of system, but the prediction of the state of the system can be used for the load balancing that will further improve the hit rate. In this study, a Hot Spot Prediction Method (HSPM) has been suggested to improve the throughputs of the proxy. The predicted hot spots, which is the item most frequently requested, should be predicted beforehand. The result show that the suggested method is better than the consistent hashing in the point of the load balancing and the hit rate.