83 research outputs found

    The Hochschild cohomology ring of a global quotient orbifold

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    We study the cup product on the Hochschild cohomology of the stack quotient [X/G] of a smooth quasi-projective variety X by a finite group G. More specifically, we construct a G-equivariant sheaf of graded algebras on X whose G-invariant global sections recover the associated graded algebra of the Hochschild cohomology of [X/G], under a natural filtration. This sheaf is an algebra over the polyvector fields T^{poly}_X on X, and is generated as a T^{poly}_X-algebra by the sum of the determinants det(N_{X^g}) of the normal bundles of the fixed loci in X. We employ our understanding of Hochschild cohomology to conclude that the analog of Kontsevich's formality theorem, for the cup product, does not hold for Deligne--Mumford stacks in general. We discuss relationships with orbifold cohomology, extending Ruan's cohomological conjectures. This employs a trivialization of the determinants in the case of a symplectic group action on a symplectic variety X, which requires (for the cup product) a nontrivial normalization missing in previous literature

    Simulation model of the water balance of a cropped soil providing different types of boundary conditions (SWATRE)

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    In the present program, SWATRE(-xtended) the following types of conditions at the bottorn of the system can be used: - groundwater level; -flux from the saturated zone (prescribed); the groundwater level is computed; - flux from the saturated zone (calculated as the s~m of the flux towards ditches and the flux of deep percolation); the groundwater level is computed; - flux from the saturated zone (calculated with a flux - groundwater level relationship); the groundwater level is computed; - pressure head of bottorn compartment; - zero flux at the bottorn (of an unsaturated soil profile); i. e, when an impermeable layer is present; - free drainage at the bottorn (unit hydraulic gradient; unsaturated soil profile)

    Airway deposition of extrafine inhaled triple therapy in patients with copd: A model approach based on functional respiratory imaging computer simulations

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    Introduction: There is a clear correlation between small airways dysfunction and poor clinical outcomes in patients with chronic obstructive pulmonary disease (COPD), and it is therefore important that inhalation therapy (both bronchodilator and anti-inflammatory) can deposit in the small airways. Two single-inhaler triple therapy (SITT) combinations are currently approved for the maintenance treatment of COPD: extrafine formulation beclomethasone dipropionate/formoterol fumarate/glycopyrronium bromide (BDP/FF/GB), and nonextrafine formulation fluticasone furoate/vilanterol/umeclidinium (FluF/VI/UMEC). This study evaluated the lung deposition of the inhaled corticosteroid (ICS), long-acting ÎČ2-agonist (LABA), and long-acting muscarinic antagonist (LAMA) components of these two SITTs. Materials and Methods: Lung deposition was estimated in-silico using functional respiratory imaging, a validated technique that uses aerosol delivery performance profiles, patients’ high-resolution computed tomography (HRCT) lung scans, and patient-derived inhalation profiles to simulate aerosol lung deposition. Results: HRCT scan data from 20 patients with COPD were included in these analyses, who had post-bronchodilator forced expiratory volume in 1 second (FEV1) ranging from 19.3% to 66.0% predicted. For intrathoracic deposition (as a percentage of the emitted dose), deposition of the ICS component was higher from BDP/FF/GB than FluF/VI/UMEC; the two triple therapies had similar performance for both the LABA component and the LAMA component. Peripheral deposition of all three components was higher with BDP/FF/GB than FluF/ VI/UMEC. Furthermore, the ratios of central to peripheral deposition for all three components of BDP/FF/GB were <1, indicating greater peripheral than central deposition (0.48 ±0.13, 0.48±0.13 and 0.49±0.13 for BDP, FF and GB, respectively; 1.96±0.84, 0.97±0.34 and 1.20±0.48 for FluF, VI and UMEC, respectively). Conclusions: Peripheral (small airways) deposition of all three components (ICS, LABA, and LAMA) was higher from BDP/FF/GB than from FluF/VI/UMEC, based on profiles from patients with moderate to very severe COPD. This is consistent with the extrafine formulation of BDP/FF/GB

    Dynamic stroma reorganization drives blood vessel dysmorphia during glioma growth

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    Glioma growth and progression are characterized by abundant development of blood vessels that are highly aberrant and poorly functional, with detrimental consequences for drug delivery efficacy. The mechanisms driving this vessel dysmorphia during tumor progression are poorly understood. Using longitudinal intravital imaging in a mouse glioma model, we identify that dynamic sprouting and functional morphogenesis of a highly branched vessel network characterize the initial tumor growth, dramatically changing to vessel expansion, leakage, and loss of branching complexity in the later stages. This vascular phenotype transition was accompanied by recruitment of predominantly pro-inflammatory M1-like macrophages in the early stages, followed by in situ repolarization to M2-like macrophages, which produced VEGF-A and relocate to perivascular areas. A similar enrichment and perivascular accumulation of M2 versus M1 macrophages correlated with vessel dilation and malignancy in human glioma samples of different WHO malignancy grade. Targeting macrophages using anti-CSF1 treatment restored normal blood vessel patterning and function. Combination treatment with chemotherapy showed survival benefit, suggesting that targeting macrophages as the key driver of blood vessel dysmorphia in glioma progression presents opportunities to improve efficacy of chemotherapeutic agents. We propose that vessel dysfunction is not simply a general feature of tumor vessel formation, but rather an emergent property resulting from a dynamic and functional reorganization of the tumor stroma and its angiogenic influences

    Contextualising adverse events of special interest to characterise the baseline incidence rates in 24 million patients with COVID-19 across 26 databases: a multinational retrospective cohort study

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    BACKGROUND: Adverse events of special interest (AESIs) were pre-specified to be monitored for the COVID-19 vaccines. Some AESIs are not only associated with the vaccines, but with COVID-19. Our aim was to characterise the incidence rates of AESIs following SARS-CoV-2 infection in patients and compare these to historical rates in the general population. METHODS: A multi-national cohort study with data from primary care, electronic health records, and insurance claims mapped to a common data model. This study's evidence was collected between Jan 1, 2017 and the conclusion of each database (which ranged from Jul 2020 to May 2022). The 16 pre-specified prevalent AESIs were: acute myocardial infarction, anaphylaxis, appendicitis, Bell's palsy, deep vein thrombosis, disseminated intravascular coagulation, encephalomyelitis, Guillain- Barré syndrome, haemorrhagic stroke, non-haemorrhagic stroke, immune thrombocytopenia, myocarditis/pericarditis, narcolepsy, pulmonary embolism, transverse myelitis, and thrombosis with thrombocytopenia. Age-sex standardised incidence rate ratios (SIR) were estimated to compare post-COVID-19 to pre-pandemic rates in each of the databases. FINDINGS: Substantial heterogeneity by age was seen for AESI rates, with some clearly increasing with age but others following the opposite trend. Similarly, differences were also observed across databases for same health outcome and age-sex strata. All studied AESIs appeared consistently more common in the post-COVID-19 compared to the historical cohorts, with related meta-analytic SIRs ranging from 1.32 (1.05 to 1.66) for narcolepsy to 11.70 (10.10 to 13.70) for pulmonary embolism. INTERPRETATION: Our findings suggest all AESIs are more common after COVID-19 than in the general population. Thromboembolic events were particularly common, and over 10-fold more so. More research is needed to contextualise post-COVID-19 complications in the longer term. FUNDING: None

    Modeling the productivity of agricultural crops in response to water and nitrogen availability

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    Interception of photosynthetical active radiation, water and nitrogen uptake are the most important processes governing crop growth and production. Each of these processes is handled in a general way, and based on experimental evidence the main features are depicted. Light interception by a crop canopy determines the potential growth rate, provided the water and nitrogen uptake rates are optimal. Reasons for yield reductions in response to water and nitrogen shortage are clarified. During the growing period, the availability of growth factors can vary widely.Dynamic simulation models are a valuable tool in studying the quantitative aspects of crop growth processes. The way in which potential growth processes are modeled is presented. As water and nitrogen shortages put restrictions on the potential growth, these effects are modeled by their impact on relevant physiological processes. Finally, attention is paid to the practical use of simulation models with respect to agricultural crop productivity.status: publishe
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