• Title/Summary/Keyword: IutA

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Evaluation of systemic and mucosal immune responses in mice administered with recombinant Salmonella Typhimurium expressing IutA protein

  • Oh, In-Gyeong;Choi, Minsu;Lee, John Hwa
    • Korean Journal of Veterinary Research
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    • v.53 no.3
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    • pp.163-167
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    • 2013
  • Avian pathogenic Escherichia coli (APEC) are known to cause extraintestinal disease in poultry, leading to substantial losses in the industry. IutA, iron-regulated aerobactin receptor is firmly associated with APEC. To assess the potential of IutA to induce protective immune responses, attenuated Salmonella Typhimurium strain expressing IutA was constructed and administered orally to BALB/c mice. The IutA-specific immune responses were measured with sera, vaginal and fecal samples by an enzyme-linked immunosorbent assay. We found that the Salmonella-IutA vaccine induced significantly higher immune responses as compared to the control inoculated with the attenuated S. Typhimurium containing the plasmid only. The IutA-specific immune responses were increased by second immunization at third week after initial immunization, whereas triple immunization induced lower immune responses than those induced by the double immunization. The Salmonella-IutA vaccine induced a nature of immunity biased to the Th1-type, as judged by the ratio of IutA-specific IgG isotypes (IgG2a/IgG1). Overall, these results suggest that the Salmonella-IutA vaccine appear to be suitable candidate for a vaccine against APEC.

Conformance Testing of Multi-protocol IUTs (다중계층 프로토콜의 적합성시험 방안)

  • Park, Yong-Beom;Kim, Myeong-Cheol;Kim, Jang-Gyeong
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.11
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    • pp.3086-3096
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    • 1999
  • To declare conformance of multi-protocol Implementation Under Test(IUT), every layer of the multi-protocol IUT should be tested. According to ISO9646, single-layer test method is applied to testing the highest layer of multi-protocol IUT and single-layer embedded test method is used for the layers by layer all the protocols in a multi-protocol IUT. This paper proposes a new method for testing a multi-protocol IUT. The proposed test method assumes that a multi-protocol IUT is under test and that the interfaces between the layers cannot be controlled or observed by the tester. We apply the proposed test method to TCP/IP and compare the application results with those of the existing test turns out that the proposed test method significantly reduces the number of test cases as well as the number of test events while providing the same test coverage. In addition, the proposed test method shows the capability to locate the layer that is source of failure in testing multi-protocol IUTs.

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A Model-Based Analysis of Secure Video Transmission Based on IPSec and IPv4

  • Van, Quang-Dao;Wei, Anne;Geller, Benoit;Dupeyrat, Gerard
    • ETRI Journal
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    • v.27 no.2
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    • pp.219-222
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    • 2005
  • A promising solution to protect wired Internet networks is to use the Secure Internet Protocol (IPSec); however, this has some drawbacks, particularly on the quality of service (QoS). This paper aims at evaluating the video traffic QoS in terms of end-to-end delay and packet loss rate. Based on some basic assumptions, our analysis shows that the performance with IPSec is rapidly inferior to the IPv4 performance. We thus suggest adding some QoS parameters into IPSec in order to achieve a compromise between QoS and security.

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Multicast Support in DiffServ Using Mobile Agents

  • El Hachimi, Mohamed;Abouaissa, Abdelhafid;Lorenz, Pascal
    • ETRI Journal
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    • v.27 no.1
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    • pp.13-21
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    • 2005
  • Many multicast applications, such as video-on-demand and video conferencing, desire quality of service (QoS) support from an underlying network. The differentiated services (DiffServ) approach will bring benefits for theses applications. However, difficulties arise while integrating native IP multicasting with DiffServ, such as multicast group states in the core routers and a heterogeneous QoS requirement within the same multicast group. In addition, a missing per-flow reservation in DiffServ and a dynamic join/leave in the group introduce heavier and uncontrollable traffic in a network. In this paper, we propose a distributed and stateless admission control in the edge routers. We also use a mobile agents-based approach for dynamic resource availability checking. In this approach, mobile agents act in a parallel and distributed fashion and cooperate with each other in order to construct the multicast tree satisfying the QoS requirements.

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An Approach to Scheduling Bursty Traffic

  • Farzanegan, Mahmoud Daneshvar;Saidi, Hossein;Mahdavi, Mehdi
    • ETRI Journal
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    • v.36 no.1
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    • pp.69-79
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    • 2014
  • The scheduling scheme in packet switching networks is one of the most critical features that can affect the performance of the network. Hence, many scheduling algorithms have been suggested and some indices, such as fairness and latency, have been proposed for the comparison of their performances. While the nature of Internet traffic is bursty, traditional scheduling algorithms try to smooth the traffic and serve the users based on this smoothed traffic. As a result, the fairness index mainly considers this smoothed traffic and the service rate as the main parameter to differentiate among different sessions or flows. This work uses burstiness as a differentiating factor to evaluate scheduling algorithms proposed in the literature. To achieve this goal, a new index that evaluates the performance of a scheduler with bursty traffic is introduced. Additionally, this paper introduces a new scheduler that not only uses arrival rates but also considers burstiness parameters in its scheduling algorithms.