292 research outputs found

    On the Noncommutativity Approach to Supersymmetry on the Lattice

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    The noncommutativity approach to SUSY on the lattice is shown to be inconsistent and a similar inconsistency is displayed for the link approach.Comment: 3 pages; talk presented by FB at "Quark Confinement and the Hadron Spectrum VII", September 2-7, 2006, Ponta Delgada, Azores, Portuga

    Noncommutativity Approach to Supersymmetry on the Lattice: SUSY Quantum Mechanics and an Inconsistency

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    It is argued that the noncommutativity approach to fully supersymmetric field theories on the lattice suffers from an inconsistency. Supersymmetric quantum mechanics is worked out in this formalism and the inconsistency is shown both in general and explicitly for that system, as well as for the Abelian super BF model.Comment: 8 pages, typo's corrected, conclusions unchange

    A Critique of the Link Approach to Exact Lattice Supersymmetry

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    We examine the link approach to constructing a lattice theory of N=2 super Yang Mills theory in two dimensions. The goal of this construction is to provide a discretization of the continuum theory which preserves all supersymmetries at non-zero lattice spacing. We show that this approach suffers from an inconsistency and argue that a maximum of just one of the supersymmetries can be implemented on the lattice.Comment: 7 page

    Multilevel governance of coastal flood risk reduction : a public finance perspective

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    Authors acknowledge funding from the European Union's Horizon 2020 research and innovation program under Grant 642018 (GREEN‐WIN project) and funding from the project INSeaPTION as part of ERA4CS, an ERA‐NET initiated by JPI Climate, and funded by BMBF (DE), MINECO (ES), NWO (NL), and ANR (FR) with co-funding by the European Union (Grant 690462).Coastal flood risk reduction (CFRR) presents a significant public funding challenge, due to its high upfront costs and long-term benefits, and this challenge will increase with future sea-level rise. The funding challenge necessarily involves multiple levels of government, due to the regional nature of CFRR public goods involved. Yet there has been little research comparing such multilevel arrangements across countries, and in particular exploring the performance of public funding arrangements for providing coastal flood risk reduction. We address this gap, applying fiscal federalism to develop a multilevel governance analysis of public decision-making and fiscal authorities for CFRR in the Netherlands, Germany, the UK and Australia. For each country, we locate key decision-making and fiscal authorities in multilevel governance arrangements, and analyse their alignment with the benefits of CFRR measures (spillovers). We find diverse coastal flood risk governance arrangements ranging from highly centralised (NL), mixed arrangements, involving regional centralisation (Germany) or partial devolvement (UK), to full decentralisation (AUS). Further, we find that in accordance with fiscal federalism, multilevel coastal flood risk governance arrangements are generally reflective of the distribution of the benefits across different levels of government, with some exceptions (Germany and UK). Finally, exploring the outlook of current arrangements under sea-level rise, we find that major fiscal redistributions may be put under pressure by rising costs likely under SLR and future coastal development. This is particularly the case for those systems which operate under hazard-based, as opposed to risk-based, coastal protection policies. Further, we find that both fully and moderately decentralised arrangements may require greater central support for alternative measures, such as retreat, in light of growing financial burdens on local governments.PostprintPeer reviewe

    Staphylococcus aureus toxin LukSF dissociates from its membrane receptor target to enable renewed ligand sequestration

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    Staphylococcus aureus Panton-Valentine leukocidin is a pore-forming toxin targeting the human C5a receptor (hC5aR), enabling this pathogen to battle the immune response by destroying phagocytes through targeted lysis. The mechanisms that contribute to rapid cell lysis are largely unexplored. Here, we show that cell lysis may be enabled by a process of toxins targeting receptor clusters and present indirect evidence for receptor recycling that allows multiple toxin pores to be formed close together. With the use of live cell single-molecule super-resolution imaging, Forster resonance energy transfer and nanoscale total internal reflection fluorescence colocalization microscopy, we visualized toxin pore formation in the presence of its natural docking ligand. We demonstrate disassociation of hC5aR from toxin complexes and simultaneous binding of new ligands. This effect may free mobile receptors to amplify hyperinflammatory reactions in early stages of microbial infections and have implications for several other similar bicomponent toxins and the design of new antibiotics.Haapasalo, K., Wollman, A. J. M., de Haas, C. J. C., van Kessel, K. P. M., van Strijp, J. A. G., Leake, M. C. Staphylococcus aureus toxin LukSF dissociates from its membrane receptor target to enable renewed ligand sequestration.Peer reviewe

    Exploring discordance between Health Literacy Questionnaire scores of people with RMDs and assessment by treating health professionals

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    OBJECTIVES: We studied discordance between health literacy of people with rheumatic and musculoskeletal diseases (RMDs) and assessment of health literacy by their treating health professionals, and explored whether discordance is associated with the patients' socioeconomic background. METHODS: Patients with rheumatoid arthritis (RA), spondyloarthritis (SpA), or gout from three Dutch outpatient rheumatology clinics completed the nine-domain Health Literacy Questionnaire (HLQ). Treating health professionals assessed their patients on each HLQ domain. Discordance per domain was defined as a ≥ 2-point difference on a 0-10 scale (except if both scores were below three or above seven), leading to three categories: "negative discordance" (i.e. professional scored lower), "probably the same", or "positive discordance" (i.e. professional scored higher). We used multivariable multilevel multinomial regression models with patients clustered by health professionals to test associations with socioeconomic factors (age, gender, education level, migration background, employment, disability for work, living alone). RESULTS: We observed considerable discordance (21-40% of patients) across HLQ domains. Most discordance occurred for "Critically appraising information" (40.5%, domain 5). Comparatively, positive discordance occurred more frequently. Negative discordance was more frequently and strongly associated with socioeconomic factors, specifically lower education level and non-Western migration background (for five HLQ domains). Associations between socioeconomic factors and positive discordance were less consistent. CONCLUSION: Frequent discordance between patients' scores and professionals' estimations indicates there may be hidden challenges in communication and care, which differ between socioeconomic groups. Successfully addressing patients' health literacy needs cannot solely depend on health professionals' estimations but will require measurement and dialogue

    Adjuvant capecitabine-containing chemotherapy benefit and homologous recombination deficiency in early-stage triple-negative breast cancer patients

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    Background The addition of adjuvant capecitabine to standard chemotherapy of early-stage triple-negative breast cancer (TNBC) patients has improved survival in a few randomised trials and in meta-analyses. However, many patients did not benefit. We evaluated the BRCA1-like DNA copy number signature, indicative of homologous recombination deficiency, as a predictive biomarker for capecitabine benefit in the TNBC subgroup of the FinXX trial. Methods Early-stage TNBC patients were randomised between adjuvant capecitabine-containing (TX + CEX: capecitabine-docetaxel, followed by cyclophosphamide-epirubicin-capecitabine) and conventional chemotherapy (T + CEF: docetaxel, followed by cyclophosphamide-epirubicin-fluorouracil). Tumour BRCA1-like status was determined on low-coverage, whole genome next-generation sequencing data using an established DNA comparative genomic hybridisation algorithm. Results For 129/202 (63.9%) patients the BRCA1-like status could be determined, mostly due to lack of tissue. During a median follow-up of 10.7 years, 35 recurrences and 32 deaths occurred. Addition of capecitabine appears to improve recurrence-free survival more among 61 (47.3%) patients with non-BRCA1-like tumours (HR 0.23, 95% CI 0.08-0.70) compared to 68 (52.7%) patients with BRCA1-like tumours (HR 0.66, 95% CI 0.24-1.81) (P-interaction = 0.17). Conclusion Based on our data, patients with non-BRCA1-like TNBC appear to benefit from the addition of capecitabine to adjuvant chemotherapy. Patients with BRCA1-like TNBC may also benefit. Additional research is needed to define the subgroup within BRCA1-like TNBC patients who may not benefit from adjuvant capecitabine.Peer reviewe

    Masses, Radii, and Cloud Properties of the HR 8799 Planets

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    The near-infrared colors of the planets directly imaged around the A star HR 8799 are much redder than most field brown dwarfs of the same effective temperature. Previous theoretical studies of these objects have concluded that the atmospheres of planets b, c, and d are unusually cloudy or have unusual cloud properties. Some studies have also found that the inferred radii of some or all of the planets disagree with expectations of standard giant planet evolution models. Here we compare the available data to the predictions of our own set of atmospheric and evolution models that have been extensively tested against observations of field L and T dwarfs, including the reddest L dwarfs. Unlike some previous studies we require mutually consistent choices for effective temperature, gravity, cloud properties, and planetary radius. This procedure thus yields plausible values for the masses, effective temperatures, and cloud properties of all three planets. We find that the cloud properties of the HR 8799 planets are not unusual but rather follow previously recognized trends, including a gravity dependence on the temperature of the L to T spectral transition--some reasons for which we discuss. We find the inferred mass of planet b is highly sensitive to whether or not we include the H and K band spectrum in our analysis. Solutions for planets c and d are consistent with the generally accepted constraints on the age of the primary star and orbital dynamics. We also confirm that, like in L and T dwarfs and solar system giant planets, non-equilibrium chemistry driven by atmospheric mixing is also important for these objects. Given the preponderance of data suggesting that the L to T spectral type transition is gravity dependent, we present an exploratory evolution calculation that accounts for this effect. Finally we recompute the the bolometric luminosity of all three planets.Comment: 52 pages, 12 figures, Astrophysical Journal, in press. v2 features minor editorial updates and correction

    Assessing quality of hepato-pancreato-biliary surgery: nationwide benchmarking

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    Background: Clinical auditing is a powerful tool to evaluate and improve healthcare. Deviations from the expected quality of care are identified by benchmarking the results of individual hospitals using national averages. This study aimed to evaluate the use of quality indicators for benchmarking hepato-pancreato-biliary (HPB) surgery and when outlier hospitals could be identified. Methods: A population-based study used data from two nationwide Dutch HPB audits (DHBA and DPCA) from 2014 to 2021. Sample size calculations determined the threshold (in percentage points) to identify centres as statistical outliers, based on current volume requirements (annual minimum of 20 resections) on a two-year period (2020–2021), covering mortality rate, failure to rescue (FTR), major morbidity rate and textbook/ideal outcome (TO) for minor liver resection (LR), major LR, pancreaticoduodenectomy (PD) and distal pancreatectomy (DP). Results: In total, 10 963 and 7365 patients who underwent liver and pancreatic resection respectively were included. Benchmark and corresponding range of mortality rates were 0.6% (0 −3.2%) and 3.3% (0–16.7%) for minor and major LR, and 2.7% (0–7.0%) and 0.6% (0–4.2%) for PD and DP respectively. FTR rates were 5.4% (0–33.3%), 14.2% (0–100%), 7.5% (1.6%–28.5%) and 3.1% (0–14.9%). For major morbidity rate, corresponding rates were 9.8% (0–20.5%), 28.1% (0–47.1%), 36% (15.8%–58.3%) and 22.3% (5.2%–46.1%). For TO, corresponding rates were 73.6% (61.3%–94.4%), 54.1% (35.3–100), 46.8% (25.3%–59.4%) and 63.3% (30.7%–84.6%). Mortality rate thresholds indicating a significant outlier were 8.6% and 15.4% for minor and major LR and 14.2% and 8.6% for PD and DP. For FTR, these thresholds were 17.9%, 31.6%, 22.9% and 15.0%. For major morbidity rate, these thresholds were 26.1%, 49.7%, 57.9% and 52.9% respectively. For TO, lower thresholds were 52.5%, 32.5%, 25.8% and 41.4% respectively. Higher hospital volumes decrease thresholds to detect outliers. Conclusion: Current event rates and minimum volume requirements per hospital are too low to detect any meaningful between hospital differences in mortality rate and FTR. Major morbidity rate and TO are better candidates to use for benchmarking

    Assessing quality of hepato-pancreato-biliary surgery: nationwide benchmarking

    Get PDF
    Background: Clinical auditing is a powerful tool to evaluate and improve healthcare. Deviations from the expected quality of care are identified by benchmarking the results of individual hospitals using national averages. This study aimed to evaluate the use of quality indicators for benchmarking hepato-pancreato-biliary (HPB) surgery and when outlier hospitals could be identified. Methods: A population-based study used data from two nationwide Dutch HPB audits (DHBA and DPCA) from 2014 to 2021. Sample size calculations determined the threshold (in percentage points) to identify centres as statistical outliers, based on current volume requirements (annual minimum of 20 resections) on a two-year period (2020–2021), covering mortality rate, failure to rescue (FTR), major morbidity rate and textbook/ideal outcome (TO) for minor liver resection (LR), major LR, pancreaticoduodenectomy (PD) and distal pancreatectomy (DP). Results: In total, 10 963 and 7365 patients who underwent liver and pancreatic resection respectively were included. Benchmark and corresponding range of mortality rates were 0.6% (0 −3.2%) and 3.3% (0–16.7%) for minor and major LR, and 2.7% (0–7.0%) and 0.6% (0–4.2%) for PD and DP respectively. FTR rates were 5.4% (0–33.3%), 14.2% (0–100%), 7.5% (1.6%–28.5%) and 3.1% (0–14.9%). For major morbidity rate, corresponding rates were 9.8% (0–20.5%), 28.1% (0–47.1%), 36% (15.8%–58.3%) and 22.3% (5.2%–46.1%). For TO, corresponding rates were 73.6% (61.3%–94.4%), 54.1% (35.3–100), 46.8% (25.3%–59.4%) and 63.3% (30.7%–84.6%). Mortality rate thresholds indicating a significant outlier were 8.6% and 15.4% for minor and major LR and 14.2% and 8.6% for PD and DP. For FTR, these thresholds were 17.9%, 31.6%, 22.9% and 15.0%. For major morbidity rate, these thresholds were 26.1%, 49.7%, 57.9% and 52.9% respectively. For TO, lower thresholds were 52.5%, 32.5%, 25.8% and 41.4% respectively. Higher hospital volumes decrease thresholds to detect outliers. Conclusion: Current event rates and minimum volume requirements per hospital are too low to detect any meaningful between hospital differences in mortality rate and FTR. Major morbidity rate and TO are better candidates to use for benchmarking
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