176 research outputs found

    Success Factors of International Education and Training Networks

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    In the last decade, several international education and training networks have been established in the nuclear field, striving to support – in general terms – the availability of qualified human resources in nuclear facilities (including research centers). Re-cently, several cooperation agreements have been signed between different net-works with the aim to further boost the impact and effectiveness of their work. The networks have become active in different geographical regions of the world, and their creation has been supported by different international organizations. Consequently, for stakeholders in the nuclear field it is increasingly difficult to receive an overview, and to differentiate substantially between the education and training impacts on their own human resource issues. In order to present an overview and a clearer view on existing education and training networks, and to assess the potential benefits of their work for concerned stakehold-ers, this paper presents 2 examples (European Nuclear Education Network / ENEN, European Fusion Education Network / FuseNet), comparing their history, their target groups and their members, their mission and objectives, their activities and working mechanisms, as well as their information and communication (web sites). The objective is to develop criteria and in particular success factors that may provide guidance for further development of international education and training networks

    Analyses of instability events in the Peach Bottom-2 BWR using thermal-hydraulic and 3D neutron kinetic coupled codes technique

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    Boiling water reactor (BWR) instabilities may occur when, starting from a stable operating condition, changes in system parameters bring the reactor towards an unstable region. In order to design more stable and safer core configurations, experimental and theoretical studies about BWR stability have been performed to characterise the phenomenon and to predict the conditions for its occurrence. In this work, contributions to the study of BWR instability phenomena are presented. The RELAP5/MOD3.3 thermal-hydraulic (TH) system code and the PARCS-2.4 3D neutron kinetic (NK) code were coupled to simulate BWR transients. Different algorithms were used to calculate the decay ratio (DR) and the natural frequency (NF) from the power oscillation predicted by the transient calculations as two typical parameters used to provide a quantitative description of instabilities. The validation of the code model set up for the Peach Bottom Unit 2 BWR plant is performed against low-flow stability tests (LFSTs). The four series of LFST have been performed during the first quarter of 1977 at the end of cycle 2 in Pennsylvania. The tests were intended to measure the reactor core stability margins at the limiting conditions used in design and safety analyses

    Nucleosome eviction from MHC class II promoters controls positioning of the transcription start site

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    Nucleosome depletion at transcription start sites (TSS) has been documented genome-wide in multiple eukaryotic organisms. However, the mechanisms that mediate this nucleosome depletion and its functional impact on transcription remain largely unknown. We have studied these issues at human MHC class II (MHCII) genes. Activation-induced nucleosome free regions (NFR) encompassing the TSS were observed at all MHCII genes. Nucleosome depletion was exceptionally strong, attaining over 250-fold, at the promoter of the prototypical HLA-DRA gene. The NFR was induced primarily by the transcription factor complex that assembles on the conserved promoter-proximal enhancer situated upstream of the TSS. Functional analyses performed in the context of native chromatin demonstrated that displacing the NFR without altering the sequence of the core promoter induced a shift in the position of the TSS. The NFR thus appears to play a critical role in transcription initiation because it directs correct TSS positioning in vivo. Our results provide support for a novel mechanism in transcription initiation whereby the position of the TSS is controlled by nucleosome eviction rather than by promoter sequenc

    Assessing Nitrogen Limitation in Inoculated Soybean in Southern Brazil

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    Core Ideas Soybean yield did not respond to low starter fertilizer N rates in soils with high organic matter content. Nitrogen limitation tended to be greater in low compared with medium-high yield levels. Nitrogen limitation is potentially related to lower contribution of N coming from biological nitrogen fixation (BNF) and mineralization. Overcoming potential N limitation in soybean [Glycine max (L.) Merr.] is a critical factor for sustaining plant nutrient demand and improving productivity. Following this rationale, a set of studies were executed in southern Brazil with the goals of quantifying yield response to early season fertilizer N rates (up to 40 kg ha−1), “starter N fertilization,” and to understand if soybean seed yields are limited by N (testing a non-limiting N scenario) when grown in soils with medium to high organic matter content. The main key outcomes of this research were: (i) starter N fertilization did not increase yields compared with non-fertilized soybean, potentially highlighting the absence of an early season N limitation; and (ii) N limitation was observed when soybean yields were compared with non-limiting N scenario and it tended to be greater in low compared with medium-high yield levels, potentially connected with co-limitations on both N sources (N2 fixation and mineralization) to satisfy soybean N demand. Producing soybean in a sustainable manner implies focus on production practices to conserve and, potentially, to increase soil organic matter on a long-term basis. Furthermore, it requires enhancing the biological N2 fixation process for satisfying the large plant N demand for achieving high soybean yields. Future research should be focused on understanding factors governing biological N2 fixation and N mineralization processes in soybean grown in soils with medium-high organic matter content.Fil: Ambrosini, VĂ­tor Gabriel. Universidade Federal do Rio Grande do Sul; BrasilFil: Vieira Fontoura, Sandra Mara. Fundação AgrĂĄria de Pesquisa AgropecuĂĄria; BrasilFil: Paulo de Moraes, Renato. Fundação AgrĂĄria de Pesquisa AgropecuĂĄria; BrasilFil: Carciochi, Walter Daniel. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Mar del Plata; ArgentinaFil: Ciampitti, Ignacio Antonio. Kansas State University; Estados UnidosFil: Bayer, CimĂ©lio. Universidade Federal do Rio Grande do Sul; Brasi

    THE EUROPEAN NUCLEAR EDUCATION NETWORK AND ITS ACTIONS IN FAVOUR OF EDUCATION, TRAINING, INFORMATION AND TRANSFER OF EXPERTISE

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    The European Nuclear Education Network (ENEN) Association is a non-profit organization established by the consortium of the EU 5th Framework Programme (FP) “ENEN” project in 2003. The ENEN Association started as a network of universities and research centers involved in education and training in nuclear engineering in EU countries and is presently involved in the challenging role of coordinating E&T in the nuclear fields in Europe. The main objective of ENEN is, in fact, the preservation and further development of expertise in the nuclear fields by higher education and training. Its members are now universities, research centers and industrial bodies established in European Countries; in addition, MoUs have been signed with several institutions and networks beyond the borders of European Union, thus reaching the number of more than 60 members. The objective of this paper is to provide an up to date view of the actions and plans of the Association in pursuing its missions

    Infrastructure and international cooperation in research and knowledge transfer: supporting access to key infrastructures and pan-European research − lessons learned

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    Access to research infrastructures has been supported by the European Commission under different financial schemes. During the 6th EURATOM Framework Programme the instrument introduced by the European Commission were the Integrated Infrastructure Initiatives (I-3). Moreover, funding schemes to support Education and Training for students and professional developments were defined also. The main difference between these two funding schemes is that I-3 are topic-driven projects with access to infrastructure components, while the Education and Training related projects have a mobility component that is applied for the different research topics. The outcome of projects as TALISMAN (I-3), EFNUDAT/NUDAME (I-3), GENTLE (mobility), ENEN-plus (mobility), NUGENIA-plus (mobility within TA of NUGENIA) and ESNII-plus (I-3 similar) will be shortly presented as well as the future European Commission plans in the field of access to research infrastructure

    Education, training and mobility: towards a common effort to assure a future workforce in Europe and abroad

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    The paper highlights the main features of some Euratom projects, which have been running recently in support to education, training and mobility in the nuclear fields. The described projects address various critical aspects of nuclear knowledge management, aiming at maintaining the wealth of nuclear expertise in Europe in an environment characterised by decreased attractiveness of nuclear careers. In an effort to broaden the cooperation and to further extend the opportunities for mobility, some projects ran in parallel with similar initiatives undertaken beyond the European borders. The lesson learnt in terms of successes achieved and critical aspects revealed by the different actions are finally discussed also considering recent recommendations and assessed scenarios by the European Commission for the decarbonisation of the energy sector

    Strange Quark Matter and Compact Stars

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    Astrophysicists distinguish between three different types of compact stars. These are white dwarfs, neutron stars, and black holes. The former contain matter in one of the densest forms found in the Universe which, together with the unprecedented progress in observational astronomy, make such stars superb astrophysical laboratories for a broad range of most striking physical phenomena. These range from nuclear processes on the stellar surface to processes in electron degenerate matter at subnuclear densities to boson condensates and the existence of new states of baryonic matter--like color superconducting quark matter--at supernuclear densities. More than that, according to the strange matter hypothesis strange quark matter could be more stable than nuclear matter, in which case neutron stars should be largely composed of pure quark matter possibly enveloped in thin nuclear crusts. Another remarkable implication of the hypothesis is the possible existence of a new class of white dwarfs. This article aims at giving an overview of all these striking physical possibilities, with an emphasis on the astrophysical phenomenology of strange quark matter. Possible observational signatures associated with the theoretically proposed states of matter inside compact stars are discussed as well. They will provide most valuable information about the phase diagram of superdense nuclear matter at high baryon number density but low temperature, which is not accessible to relativistic heavy ion collision experiments.Comment: 58 figures, to appear in "Progress in Particle and Nuclear Physics"; References added for sections 1,2,3,5; Equation (116) corrected; Figs. 1 and 58 update

    Nucleosome eviction from MHC class II promoters controls positioning of the transcription start site

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    Nucleosome depletion at transcription start sites (TSS) has been documented genome-wide in multiple eukaryotic organisms. However, the mechanisms that mediate this nucleosome depletion and its functional impact on transcription remain largely unknown. We have studied these issues at human MHC class II (MHCII) genes. Activation-induced nucleosome free regions (NFR) encompassing the TSS were observed at all MHCII genes. Nucleosome depletion was exceptionally strong, attaining over 250-fold, at the promoter of the prototypical HLA-DRA gene. The NFR was induced primarily by the transcription factor complex that assembles on the conserved promoter-proximal enhancer situated upstream of the TSS. Functional analyses performed in the context of native chromatin demonstrated that displacing the NFR without altering the sequence of the core promoter induced a shift in the position of the TSS. The NFR thus appears to play a critical role in transcription initiation because it directs correct TSS positioning in vivo. Our results provide support for a novel mechanism in transcription initiation whereby the position of the TSS is controlled by nucleosome eviction rather than by promoter sequence

    The impact of alliance management capabilities on alliance attributes and performance: A literature review

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    The literature on alliances has identified a variety of inter-firm antecedents of performance, including information and knowledge sharing between partners, shared partner understanding, and a focus on collective objectives. Recent studies have focused on alliance management capabilities (AMC) - firms' abilities to capture, share, store and apply alliance management knowledge - as an important antecedent of performance. This paper reviews 90 studies on AMC and makes two important contributions to the literature. First, the review provides an overview of and classification scheme for the different types of AMC to better organise the diverse empirical findings that have been presented in the literature. The novel classification distinguishes between general and partner-specific AMC and between AMC stored within the firm and within the alliance. Second, consistent with the dynamic capabilities perspective, this paper offers a more detailed understanding of why AMC improve performance, by highlighting the intermediate impact of AMC on alliance attributes. In particular, the review demonstrates how the different categories of AMC influence alliances in terms of information and knowledge-sharing between partners, shared partner understanding and the pursuit of collective goals. The review also demonstrates that these attributes improve performance. The authors note promising avenues for future empirical research that involve combining the classification scheme with research on the impact of AMC on alliance attributes and performance
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