809 research outputs found

    A large bioassay identifies Stb resistance genes that provide broad resistance against Septoria tritici blotch Disease in the UK

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    Septoria tritici blotch (STB) is one of the most damaging fungal diseases of wheat in Europe, largely due to the paucity of effective resistance genes against it in breeding materials. Currently dominant protection methods against this disease, e.g. fungicides and the disease resistance genes already deployed, are losing their effectiveness. Therefore, it is vital that other available disease resistance sources are identified, understood and deployed in a manner that maximises their effectiveness and durability. In this study, we assessed wheat genotypes containing nineteen known major STB resistance genes (Stb1 through to Stb19) or combinations thereof against a broad panel of 93 UK Zymoseptoria tritici isolates. Five infection symptom components (days post infection to the development of first symptoms and pycnidia, percentage coverage of the infected leaf area with chlorosis/necrosis and pycnidia and spore counts from spore wash) were measured and average disease levels calculated for each genotype. The different Stb genes were found to vary greatly in the levels of protection they provided, with no Z. tritici isolate found to be virulent against all tested resistance genes. Disease resistance controlled by different Stb genes was associated with different levels of chlorosis, with high levels of early chlorosis in some genotypes correlated with high resistance to fungal pycnidia development. Stb10, Stb11, Stb12, Stb16q, Stb17, and Stb19 were identified as contributing broad spectrum disease resistance, and synthetic hexaploid wheat lines were identified as particularly promising sources of broadly effective STB resistances. Wheat genotypes carrying multiple Stb genes were found to provide higher levels of resistance than expected given their historical levels of use. The knowledge obtained here will aid UK breeders in prioritising Stb genes for future breeding programmes. In addition, this study identified the most interesting Stb genes for cloning and detailed functional analysis

    Casting a wide net for innovation: The mediating effect of R&D human and social capital to unlock the value from Alliance Portfolio Diversity

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    This paper examines the performance effects associated with different alliance portfolio configurations in terms of geographical location and partner type. Based on these distinctions, we hypothesise that more diverse alliance portfolios enable firms to gain and exploit innovation opportunities. Additionally, the mediating effects of R&D human and social capital on the R&D alliance portfolio diversity-innovation performance relationship are explored. We reason that the absorptive capacity of R&D intellectual capital determines a firm’s potential gains from highly diverse alliance portfolios. Using panel data of manufacturing firms in Spain for the period 2008-2013, our results confirm the inverted U-shaped relationship between alliance portfolio diversity and firm innovation performance, implying that both insufficient and excessive alliance portfolio diversity may be detrimental to firm innovativeness. Additionally, R&D human and social capital partially mediates the R&D alliance diversity-innovation performance relationship emphasising the importance of internal capabilities to leverage the benefits of highly diverse alliance portfolios. These findings add a dynamic dimension to the conceptualisation of alliance portfolios and how firms create value by balancing explorative and exploitative alliances

    How Much DC Power Is Necessary?

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    Many proposals for future power systems for warships are extant. Anticipated improvements in capability, operating economy, and signature reduction may not be uniquely associated with these power systems. Alternatives are available for constructing variable speed drives and prime movers for ships with electric drives. These alternatives may open new design possibilities

    A large bioassay identifies Stb resistance genes that provide broad resistance against Septoria tritici blotch disease in the UK

    Get PDF
    Introduction: Septoria tritici blotch (STB) is one of the most damaging fungal diseases of wheat in Europe, largely due to the paucity of effective resistance genes against it in breeding materials. Currently dominant protection methods against this disease, e.g. fungicides and the disease resistance genes already deployed, are losing their effectiveness. Therefore, it is vital that other available disease resistance sources are identified, understood and deployed in a manner that maximises their effectiveness and durability. Methods: In this study, we assessed wheat genotypes containing nineteen known major STB resistance genes (Stb1 through to Stb19) or combinations thereof against a broad panel of 93 UK Zymoseptoria tritici isolates. Seedlings were inoculated using a cotton swab and monitored for four weeks. Four infection-related phenotypic traits were visually assessed. These were the days post infection to the development of first symptoms and pycnidia, percentage coverage of the infected leaf area with chlorosis/necrosis and percentage coverage of the infected leaf area with pycnidia. Results: The different Stb genes were found to vary greatly in the levels of protection they provided, with pycnidia coverage at four weeks differing significantly from susceptible controls for every tested genotype. Stb10, Stb11, Stb12, Stb16q, Stb17, and Stb19 were identified as contributing broad spectrum disease resistance, and synthetic hexaploid wheat lines were identified as particularly promising sources of broadly effective STB resistances. Discussion: No single Z. tritici isolate was found to be virulent against all tested resistance genes. Wheat genotypes carrying multiple Stb genes were found to provide higher levels of resistance than expected given their historical levels of use. Furthermore, it was noted that disease resistance controlled by different Stb genes was associated with different levels of chlorosis, with high levels of early chlorosis in some genotypes correlated with high resistance to fungal pycnidia development, potentially suggesting the presence of multiple resistance mechanisms. The knowledge obtained here will aid UK breeders in prioritising Stb genes for future breeding programmes, in which optimal combinations of resistance genes could be pyramided. In addition, this study identified the most interesting Stb genes for cloning and detailed functional analysis

    Understanding innovators' experiences of barriers and facilitators in implementation and diffusion of healthcare service innovations: A qualitative study

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    This article is made available through the Brunel Open Access Publishing Fund - Copyright @ 2011 Barnett et al.Background: Healthcare service innovations are considered to play a pivotal role in improving organisational efficiency and responding effectively to healthcare needs. Nevertheless, healthcare organisations encounter major difficulties in sustaining and diffusing innovations, especially those which concern the organisation and delivery of healthcare services. The purpose of the present study was to explore how healthcare innovators of process-based initiatives perceived and made sense of factors that either facilitated or obstructed the innovation implementation and diffusion. Methods: A qualitative study was designed. Fifteen primary and secondary healthcare organisations in the UK, which had received health service awards for successfully generating and implementing service innovations, were studied. In-depth, semi structured interviews were conducted with the organisational representatives who conceived and led the development process. The data were recorded, transcribed and thematically analysed. Results: Four main themes were identified in the analysis of the data: the role of evidence, the function of inter-organisational partnerships, the influence of human-based resources, and the impact of contextual factors. "Hard" evidence operated as a proof of effectiveness, a means of dissemination and a pre-requisite for the initiation of innovation. Inter-organisational partnerships and people-based resources, such as champions, were considered an integral part of the process of developing, establishing and diffusing the innovations. Finally, contextual influences, both intra-organisational and extra-organisational were seen as critical in either impeding or facilitating innovators' efforts. Conclusions: A range of factors of different combinations and co-occurrence were pointed out by the innovators as they were reflecting on their experiences of implementing, stabilising and diffusing novel service initiatives. Even though the innovations studied were of various contents and originated from diverse organisational contexts, innovators' accounts converged to the significant role of the evidential base of success, the inter-personal and inter-organisational networks, and the inner and outer context. The innovators, operating themselves as important champions and being often willing to lead constructive efforts of implementation to different contexts, can contribute to the promulgation and spread of the novelties significantly.This research was supported financially by the Multidisciplinary Assessment of Technology Centre for Healthcare (MATCH)
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