14 research outputs found

    Exploring Cosmic Origins with CORE: Cosmological Parameters

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    We forecast the main cosmological parameter constraints achievable with theCORE space mission which is dedicated to mapping the polarisation of the CosmicMicrowave Background (CMB). CORE was recently submitted in response to ESA'sfifth call for medium-sized mission proposals (M5). Here we report the resultsfrom our pre-submission study of the impact of various instrumental options, inparticular the telescope size and sensitivity level, and review the great,transformative potential of the mission as proposed. Specifically, we assessthe impact on a broad range of fundamental parameters of our Universe as afunction of the expected CMB characteristics, with other papers in the seriesfocusing on controlling astrophysical and instrumental residual systematics. Inthis paper, we assume that only a few central CORE frequency channels areusable for our purpose, all others being devoted to the cleaning ofastrophysical contaminants. On the theoretical side, we assume LCDM as ourgeneral framework and quantify the improvement provided by CORE over thecurrent constraints from the Planck 2015 release. We also study the jointsensitivity of CORE and of future Baryon Acoustic Oscillation and Large ScaleStructure experiments like DESI and Euclid. Specific constraints on the physicsof inflation are presented in another paper of the series. In addition to thesix parameters of the base LCDM, which describe the matter content of aspatially flat universe with adiabatic and scalar primordial fluctuations frominflation, we derive the precision achievable on parameters like thosedescribing curvature, neutrino physics, extra light relics, primordial heliumabundance, dark matter annihilation, recombination physics, variation offundamental constants, dark energy, modified gravity, reionization and cosmicbirefringence. (ABRIDGED

    Implicit high-order Discontinuous Galerkin solution of turbulent flows with an Explicit Algebraic Reynolds Stress Model

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    In this work we present an implicit high-order Discontinuous Galerkin (DG) implementation of the Explicit Algebraic Reynolds Stress Model (EARSM) of Wallin and Johansson [21]. The aim is to investigate the numerical issues related to the EARSM implementation in the framework of a very high-order DG discretization and to assess the modelling capabilities of EARSM when dealing with turbulent flows of aeronautical interest. The EARSM model has been implemented in the implicit high-order DG code MIGALE [5] and employs the Îș-ω model as the two-equation underlying model. The Îș-ω model of the DG code MIGALE has been extensively tested on several problems and in this investigation it has been used without any recalibration of the model constants. The realizability constraint of our standard Îș-ω implementation has not been used with EARSM, as this model already provides realizable Reynolds stresses. Both 2d and 3d test cases of aeronautical flows, proposed within the EU IDIHOM project, are used to assess the behaviour of the EARSM in the context of high-order DG discretization of the RANS and Îș-ω equations

    Assessing the cost-effectiveness of waiting list reduction strategies for a breast radiology department: a real-life case study

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    Abstract Background A timely diagnosis is essential for improving breast cancer patients’ survival and designing targeted therapeutic plans. For this purpose, the screening timing, as well as the related waiting lists, are decisive. Nonetheless, even in economically advanced countries, breast cancer radiology centres fail in providing effective screening programs. Actually, a careful hospital governance should encourage waiting lists reduction programs, not only for improving patients care, but also for minimizing costs associated with the treatment of advanced cancers. Thus, in this work, we proposed a model to evaluate several scenarios for an optimal distribution of the resources invested in a Department of Breast Radiodiagnosis. Materials and methods Particularly, we performed a cost-benefit analysis as a technology assessment method to estimate both costs and health effects of the screening program, to maximise both benefits related to the quality of care and resources employed by the Department of Breast Radiodiagnosis of Istituto Tumori “Giovanni Paolo II” of Bari in 2019. Specifically, we determined the Quality-Adjusted Life Year (QALY) for estimating health outcomes, in terms of usefulness of two hypothetical screening strategies with respect to the current one. While the first hypothetical strategy adds one team made up of a doctor, a technician and a nurse, along with an ultrasound and a mammograph, the second one adds two afternoon teams. Results This study showed that the most cost-effective incremental ratio could be achieved by reducing current waiting lists from 32 to 16 months. Finally, our analysis revealed that this strategy would also allow to include more people in the screening programs (60,000 patients in 3 years)

    A NEW STANDARDIZATION 1 OF THE BELLS TEST: AN ITALIAN MULTI-CENTER NORMATIVE STUDY

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    Objective: The Bells Test is a cancellation task that is widely used for the diagnosis of unilateral spatial neglect (USN). With the aim of fostering more reliable use of this instrument, we set out to develop new norms adjusted for the possible influence of age, gender and education. We worked on the original version of the test. Method: Normative data were collected from 401 healthy participants aged between 20 and 80 years. Individual factors that could affect performance (i.e. gender, age, years of education) were considered. We computed several indices on the Bells Test including an asymmetry score, an accuracy score and execution time. Multiple regression analyses (for time measures) and generalized linear models (for accuracy measures) were used to check for the influence of individual predictors of performance on the Bells Test. Results: Data indicated a significant influence of age on the accuracy score and execution time variables and a marginally significant effect of education on the accuracy score variable. Wherever appropriate, cut-offs are provided for the three dependent scores on the Bells Test corrected for age and education. Conclusions: Based on a large normative sample, the present study provides new normative data on the Bells Test, which could lead to its reliable use in the diagnosis of USN

    Using the Oxford Cognitive Screen to Detect Cognitive Impairment in Stroke Patients: A Comparison with the Mini-Mental State Examination

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    BackgroundThe Oxford Cognitive Screen (OCS) was recently developed with the aim of describing the cognitive deficits after stroke. The scale consists of 10 tasks encompassing five cognitive domains: attention and executive function, language, memory, number processing, and praxis. OCS was devised to be inclusive and un-confounded by aphasia and neglect. As such, it may have a greater potential to be informative on stroke cognitive deficits of widely used instruments, such as the Mini-Mental State Examination (MMSE) or the Montreal Cognitive Assessment, which were originally devised for demented patients.ObjectiveThe present study compared the OCS with the MMSE with regards to their ability to detect cognitive impairments post-stroke. We further aimed to examine performance on the OCS as a function of subtypes of cerebral infarction and clinical severity.Methods325 first stroke patients were consecutively enrolled in the study over a 9-month period. The OCS and MMSE, as well as the Bamford classification and NIHSS, were given according to standard procedures.ResultsAbout a third of patients (35.3%) had a performance lower than the cutoff (<22) on the MMSE, whereas 91.6% were impaired in at least one OCS domain, indicating higher incidences of impairment for the OCS. More than 80% of patients showed an impairment in two or more cognitive domains of the OCS. Using the MMSE as a standard of clinical practice, the comparative sensitivity of OCS was 100%. Out of the 208 patients with normal MMSE performance 180 showed impaired performance in at least one domain of the OCS. The discrepancy between OCS and MMSE was particularly strong for patients with milder strokes. As for subtypes of cerebral infarction, fewer patients demonstrated widespread impairments in the OCS in the Posterior Circulation Infarcts category than in the other categories.ConclusionOverall, the results showed a much higher incidence of cognitive impairment with the OCS than with the MMSE and demonstrated no false negatives for OCS vs MMSE. It is concluded that OCS is a sensitive screen tool for cognitive deficits after stroke. In particular, the OCS detects high incidences of stroke-specific cognitive impairments, not detected by the MMSE, demonstrating the importance of cognitive profiling

    Sex-Related Differences and Factors Associated with Peri-Procedural and 1 Year Mortality in Chronic Limb-Threatening Ischemia Patients from the CLIMATE Italian Registry

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    Background: Identifying sex-related differences/variables associated with 30 day/1 year mortality in patients with chronic limb-threatening ischemia (CLTI). Methods: Multicenter/retrospective/observational study. A database was sent to all the Italian vascular surgeries to collect all the patients operated on for CLTI in 2019. Acute lower-limb ischemia and neuropathic-diabetic foot are not included. Follow-up: One year. Data on demographics/comorbidities, treatments/outcomes, and 30 day/1 year mortality were investigated. Results: Information on 2399 cases (69.8% men) from 36/143 (25.2%) centers. Median (IQR) age: 73 (66-80) and 79 (71-85) years for men/women, respectively (p < 0.0001). Women were more likely to be over 75 (63.2% vs. 40.1%, p = 0.0001). More men smokers (73.7% vs. 42.2%, p < 0.0001), are on hemodialysis (10.1% vs. 6.7%, p = 0.006), affected by diabetes (61.9% vs. 52.8%, p < 0.0001), dyslipidemia (69.3% vs. 61.3%, p < 0.0001), hypertension (91.8% vs. 88.5%, p = 0.011), coronaropathy (43.9% vs. 29.4%, p < 0.0001), bronchopneumopathy (37.1% vs. 25.6%, p < 0.0001), underwent more open/hybrid surgeries (37.9% vs. 28.8%, p < 0.0001), and minor amputations (22% vs. 13.7%, p < 0.0001). More women underwent endovascular revascularizations (61.6% vs. 55.2%, p = 0.004), major amputations (9.6% vs. 6.9%, p = 0.024), and obtained limb-salvage if with limited gangrene (50.8% vs. 44.9%, p = 0.017). Age > 75 (HR = 3.63, p = 0.003) is associated with 30 day mortality. Age > 75 (HR = 2.14, p < 0.0001), nephropathy (HR = 1.54, p < 0.0001), coronaropathy (HR = 1.26, p = 0.036), and infection/necrosis of the foot (dry, HR = 1.42, p = 0.040; wet, HR = 2.04, p < 0.0001) are associated with 1 year mortality. No sex-linked difference in mortality statistics. Conclusion: Women exhibit fewer comorbidities but are struck by CLTI when over 75, a factor associated with short- and mid-term mortality, explaining why mortality does not statistically differ between the sexes

    Exploring cosmic origins with CORE: Gravitational lensing of the CMB

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    International audienceLensing of the cosmic microwave background (CMB) is now a well-developed probe of the clustering of the large-scale mass distribution over a broad range of redshifts. By exploiting the non-Gaussian imprints of lensing in the polarization of the CMB, the CORE mission will allow production of a clean map of the lensing deflections over nearly the full-sky. The number of high-S/N modes in this map will exceed current CMB lensing maps by a factor of 40, and the measurement will be sample-variance limited on all scales where linear theory is valid. Here, we summarise this mission product and discuss the science that will follow from its power spectrum and the cross-correlation with other clustering data. For example, the summed mass of neutrinos will be determined to an accuracy of 17 meV combining CORE lensing and CMB two-point information with contemporaneous measurements of the baryon acoustic oscillation feature in the clustering of galaxies, three times smaller than the minimum total mass allowed by neutrino oscillation measurements. Lensing has applications across many other science goals of CORE, including the search for B-mode polarization from primordial gravitational waves. Here, lens-induced B-modes will dominate over instrument noise, limiting constraints on the power spectrum amplitude of primordial gravitational waves. With lensing reconstructed by CORE, one can "delens" the observed polarization internally, reducing the lensing B-mode power by 60 %. This can be improved to 70 % by combining lensing and measurements of the cosmic infrared background from CORE, leading to an improvement of a factor of 2.5 in the error on the amplitude of primordial gravitational waves compared to no delensing (in the null hypothesis of no primordial B-modes). Lensing measurements from CORE will allow calibration of the halo masses of the tens of thousands of galaxy clusters that it will find, with constraints dominated by the clean polarization-based estimators. The 19 frequency channels proposed for CORE will allow accurate removal of Galactic emission from CMB maps. We present initial findings that show that residual Galactic foreground contamination will not be a significant source of bias for lensing power spectrum measurements with CORE
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