3,105 research outputs found

    Covariance matrices and the separability problem

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    We propose a unifying approach to the separability problem using covariance matrices of locally measurable observables. From a practical point of view, our approach leads to strong entanglement criteria that allow to detect the entanglement of many bound entangled states in higher dimensions and which are at the same time necessary and sufficient for two qubits. From a fundamental perspective, our approach leads to insights into the relations between several known entanglement criteria -- such as the computable cross norm and local uncertainty criteria -- as well as their limitations.Comment: 4 pages, no figures; v3: final version to appear in PR

    IgG anti-apolipoprotein A-1 antibodies in patients with systemic lupus erythematosus are associated with disease activity and corticosteroid therapy: an observational study.

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    IgG anti-apolipoprotein A-1 (IgG anti-apoA-1) antibodies are present in patients with systemic lupus erythematosus (SLE) and may link inflammatory disease activity and the increased risk of developing atherosclerosis and cardiovascular disease (CVD) in these patients. We carried out a rigorous analysis of the associations between IgG anti-apoA-1 levels and disease activity, drug therapy, serology, damage, mortality and CVD events in a large British SLE cohort

    Hydrodynamic response of rotationally supported flows in the Small Shearing Box model

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    The hydrodynamic response of the inviscid small shearing box model of a midplane section of a rotationally supported astrophysical disk is examined. An energy functional E{\cal E} is formulated for the general nonlinear problem. It is found that the fate of disturbances is related to the conservation of this quantity which, in turn, depends on the boundary conditions utilized: E{\cal E} is conserved for channel boundary conditions while it is not conserved in general for shearing box conditions. Linearized disturbances subject to channel boundary conditions have normal-modes described by Bessel Functions and are qualitatively governed by a quantity Σ\Sigma which is a measure of the ratio between the azimuthal and vertical wavelengths. Inertial oscillations ensue if Σ>1\Sigma >1 - otherwise disturbances must in general be treated as an initial value problem. We reflect upon these results and offer a speculation.Comment: 6 pages, resubmitted to Astronomy and Astrophysics, shortened with references adde

    Working in hospitality and catering in Greece and the UK: Do trade union membership and collective bargaining still matter?

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    Existing literature suggests that terms and conditions of employment are universally poor in hospitality and catering. Based on fieldwork comprising more than 70 semi-structured in-depth interviews conducted in the UK and Greece in 2018 and 2019, this article maps the field in the two countries and discusses the key parameters that structure working conditions, pay determination, and the impact of trade unionism and absence thereof. Poor working conditions and precariousness are prevalent in both contexts as expected, but surprisingly wages and other terms and conditions at least for a significant section of the hospitality workforce are comparatively better in Greece. An explanation for these findings is suggested with reference to the tradition of collective bargaining in hotels in Greece which partially survived the 2008 crisis and the legal reforms that followed. Trade unionism, despite its weakening and discrediting, has left its mark as a tradition contributing to the emergence of formal labour-based initiatives and more broadly to maintaining an openness to collectivism and collective action, more so than in the UK context. This combination of the distinct institutional and sectoral features of the Greek case and worker agency has served to ameliorate the context and content of employment for substantial sections of the hospitality workforce

    Multifunctional enzyme engineering by computational design for lignocellulosic valorization

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    Biomass- acting enzymes are vital components of biorefinery processes that aim to convert complex, lignocellulosic biomass into fuels, chemicals and materials and therefore, much effort has focused on the improvement of their characteristics (activity, stability, cost of production, etc) as well as on the discovery and development of novel enzymes. Metagenomic approaches revealed that in the Bacteroidetes phylum functionally related genes are often organized in characteristic clusters, known as Polysaccharide Utilization Loci (PUL) reflecting that biomass- acting enzymes act in synergy and that enzyme proximity is important to target complex substrates. In this study we designed a tailored made multifunctional enzyme, combining enzymes isolated from a xylan PUL (1). Computational simulations were performed to define and optimize engineered versions of a multi-domain GH10 endo- xylanase by replacing carbohydrate binding module (CBM) and grafting two new catalytic domains: either a GH43 xylosidase or a CE1 carbohydrate-esterase activities also present in the same PUL. The multifunctional enzymes were then experimentally assessed, demonstrating that chimeric GH10-GH43 had both activities and thus represents a powerful biological tool for hemicellulose deconstruction. Bastien, G., et al. (2013). Mining for hemicellulases in the fungus-growing termite Pseudacanthotermes militaris using functional metagenomics. Biotechnology for biofuels 6(1): 7

    Willing and Able: A General Model of Organizational Responses to Normative Pressures

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    We develop a conceptual understanding of when and how organizations respond to normative pressures. More precisely, we examine two main factors underlying the willingness and ability of organizations to respond to an issue: (1) issue salience, and (2) the cost-benefit analysis of resource mobilization. We suggest that decision-makers’ interpretation of issue salience in conjunction with their perception of the costs and benefits of taking action to address the issue generates five potential responses: symbolic compliance and symbolic conformity, substantive compliance and substantive conformity, and inaction. We extend the baseline model by examining a number of boundary conditions. By focusing on the willingness and ability of organizations to respond to normative pressures, and by adopting the issue as the unit of analysis, our model helps explain intra- as well as inter-organizational response heterogeneity to institutional complexity. We contribute to the institutional research tradition and offer useful implications for managerial practice, from strategic management to policy making

    Dedicated versus mainstreaming approaches in local climate plans in Europe

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    Cities are gaining prominence committing to respond to the threat of climate change, e.g., by developing local climate plans or strategies. However, little is known regarding the approaches and processes of plan development and implementation, or the success and effectiveness of proposed measures. Mainstreaming is regarded as one approach associated with (implementation) success, but the extent of integration of local climate policies and plans in ongoing sectoral and/or development planning is unclear. This paper analyses 885 cities across the 28 European countries to create a first reference baseline on the degree of climate mainstreaming in local climate plans. This will help to compare the benefits of mainstreaming versus dedicated climate plans, looking at policy effectiveness and ultimately delivery of much needed climate change efforts at the city level. All core cities of the European Urban Audit sample were analyzed, and their local climate plans classified as dedicated or mainstreamed in other local policy initiatives. It was found that the degree of mainstreaming is low for mitigation (9% of reviewed cities; 12% of the identified plans) and somewhat higher for adaptation (10% of cities; 29% of plans). In particular horizontal mainstreaming is a major effort for local authorities; an effort that does not necessarily pay off in terms of success of action implementation. This study concludes that climate change issues in local municipalities are best tackled by either, developing a dedicated local climate plan in parallel to a mainstreamed plan or by subsequently developing first the dedicated and later a mainstreaming plan (joint or subsequent “dual track approach”). Cities that currently provide dedicated local climate plans (66% of cities for mitigation; 26% of cities for adaptation) may follow-up with a mainstreaming approach. This promises effective implementation of tangible climate actions as well as subsequent diffusion of climate issues into other local sector policies. The development of only broad sustainability or resilience strategies is seen as critical.We thank the many council representatives that supported the datacollection. Special thanks to Birgit Georgi who helped in setting up this large net work of researchers across the EU-28. We also thank the EU COST Action TU 0902 (ledbyRichardDawson) that established the core research network and the positive engagement and interaction of th emembers of this group. OH is Fellow of the Tyndall Centre for Climate Change Research and was funded by the UK EPSRC LC Transforms: Low Carbon Transitions of Fleet Operations in Metropolitan Sites Project (grant number EP/N010612/1). EKL was supported by the Ministry of Education, Youth and Sports, Czechia, within the National Sustainability Program I (NPU I) (grant number LO1415). DG ac-knowledges support by the Ministry of Education, University and Research (MIUR), Italy ("Departments of Excellence" grant L. 232/2016). HO was supported by the Ministry of Education and Research, Estonia (grantnumberIUT34-17). MO acknowledges funding from the Ministry of Economy and Competitiveness (MINECO), Spain (grant number IJCI-2016-28835). SS acknowledges that CENSE's research is partially funded by the Science Foundation, Portugal (grant number UID/AMB/04085/2019). The paper reflects only the views of the authors. The European Union, the European Environment Agency or other supporting bodies are not liable for any use that may be made of the information that is provided in this manuscript
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