| 1. |
- Ekman, M., et al.
(författare)
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Tool qualification for safety related systems
- 2014
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Ingår i: Ada User Journal. - 1381-6551. ; 35, s. 47-54
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Tidskriftsartikel (refereegranskat)abstract
- Tools used in the development of safety related software applications need to be qualified as safe. That is, the tools cannot be allowed to introduce hazardous faults into the application, e.g., a compiler shall not generate dangerous code due to failure of the compiler. In many cases laws and regulations require the product development of safety related applications to comply with industry sector specific safety standards. Examples of such standards include EN50129/50128 for railway applications, ISO/EN13849 for machines with moving parts, DO-178B/C for avionics, or IS026262 for cars. These standards require the use of a rigorous development and maintenance process. The standards are also mainly intended to be used when developing systems from scratch. However, most development and test tools are not developed from scratch according to the rigorous processes of these standards. In order to address this issue, some of the standards provide means for qualifying existing tools as a more lightweight and pragmatic alternative to a regular certification process. In this paper we analyze the concept of these qualification approaches. The result of the analysis in our contribution includes a set of approaches that can be applied individually or as a combination in order to reduce the effort needed for qualifying tools. As a running example we use one of the most flexible but at the same time dangerous, even prohibited, maintenance techniques available: dynamic instrumentation of executing code. With this example, we describe how exceptions in these standards can be utilized in order to qualify a dynamic instrumentation tool with a minimal effort, without following the process of tool certification as defined by the standards.
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| 3. |
- Lebens, Michael, 1956, et al.
(författare)
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Construction of novel vaccine strains of Vibrio cholerae co-expressing the Inaba and Ogawa serotype antigens
- 2011
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Ingår i: Vaccine. - : Elsevier BV. - 0264-410X .- 1873-2518. ; 29:43, s. 7505-7513
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Tidskriftsartikel (refereegranskat)abstract
- The approach of inducing protective immunity against cholera by oral vaccination with killed whole Vibrio cholerae cells is effective, but the complexity of current cholera vaccines makes them difficult and relatively expensive to manufacture, especially if recombinant cholera toxin B subunit is included in the formulation. In an effort to simplify the composition of a new generation of oral cholera vaccines we have generated a novel non-toxigenic candidate vaccine strain of V. cholerae O1 that stably expresses both the Ogawa and Inaba serotype antigens on its surface. This was done by introducing a functional wbeT gene without a functional promoter into the chromosome of an O1 Inaba strain. The resulting low levels of expression of the wbeT gene product allowed for the desired partial serotype switching. This strain (MS1342) can potentially replace the three virulent strains used in currently manufactured cholera vaccines. Oral immunization of mice with formalin-killed MS1342 bacteria gave rise to Ogawa-specific, Inaba-specific and cross-reactive serum antibodies that were detectable both by lipopolysaccharide (LPS)-specific ELISAs and as vibriocidal antibodies that are considered to predict protective efficacy. These responses as well as intestinal mucosal IgA anti-LPS antibody responses were fully comparable with those obtained by immunization with the internationally licensed oral cholera vaccine Dukoral ®. We propose that such a strain may form the basis of a single strain killed whole cell cholera vaccine protecting against cholera caused by either the Inaba or Ogawa serotype of V. cholerae O1.
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