152 research outputs found

    Modeling an ontology on accessible evacuation routes for emergencies

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    Providing alert communication in emergency situations is vital to reduce the number of victims. However, this is a challenging goal for researchers and professionals due to the diverse pool of prospective users, e.g. people with disabilities as well as other vulnerable groups. Moreover, in the event of an emergency situation, many people could become vulnerable because of exceptional circumstances such as stress, an unknown environment or even visual impairment (e.g. fire causing smoke). Within this scope, a crucial activity is to notify affected people about safe places and available evacuation routes. In order to address this need, we propose to extend an ontology, called SEMA4A (Simple EMergency Alert 4 [for] All), developed in a previous work for managing knowledge about accessibility guidelines, emergency situations and communication technologies. In this paper, we introduce a semi-automatic technique for knowledge acquisition and modeling on accessible evacuation routes. We introduce a use case to show applications of the ontology and conclude with an evaluation involving several experts in evacuation procedures. © 2014 Elsevier Ltd. All rights reserved

    Noise-mitigated randomized measurements and self-calibrating shadow estimation

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    Randomized measurements are increasingly appreciated as powerful tools to estimate properties of quantum systems, e.g., in the characterization of hybrid classical-quantum computation. On many platforms they constitute natively accessible measurements, serving as the building block of prominent schemes like shadow estimation. In the real world, however, the implementation of the random gates at the core of these schemes is susceptible to various sources of noise and imperfections, strongly limiting the applicability of protocols. To attenuate the impact of this shortcoming, in this work we introduce an error-mitigated method of randomized measurements, giving rise to a robust shadow estimation procedure. On the practical side, we show that error mitigation and shadow estimation can be carried out using the same session of quantum experiments, hence ensuring that we can address and mitigate the noise affecting the randomization measurements. Mathematically, we develop a picture derived from Fourier-transforms to connect randomized benchmarking and shadow estimation. We prove rigorous performance guarantees and show the functioning using comprehensive numerics. More conceptually, we demonstrate that, if properly used, easily accessible data from randomized benchmarking schemes already provide such valuable diagnostic information to inform about the noise dynamics and to assist in quantum learning procedures.Comment: 6+20 pages, 6 figure

    Shadow estimation of gate-set properties from random sequences

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    With quantum computing devices increasing in scale and complexity, there is a growing need for tools that obtain precise diagnostic information about quantum operations. However, current quantum devices are only capable of short unstructured gate sequences followed by native measurements. We accept this limitation and turn it into a new paradigm for characterizing quantum gate-sets. A single experiment—random sequence estimation—solves a wealth of estimation problems, with all complexity moved to classical post-processing. We derive robust channel variants of shadow estimation with close-to-optimal performance guarantees and use these as a primitive for partial, compressive and full process tomography as well as the learning of Pauli noise. We discuss applications to the quantum gate engineering cycle, and propose novel methods for the optimization of quantum gates and diagnosing cross-talk

    Estimating gate-set properties from random sequences

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    With quantum computing devices increasing in scale and complexity, there is a growing need for tools that obtain precise diagnostic information about quantum operations. However, current quantum devices are only capable of short unstructured gate sequences followed by native measurements. We accept this limitation and turn it into a new paradigm for characterizing quantum gate-sets. A single experiment - random sequence estimation - solves a wealth of estimation problems, with all complexity moved to classical post-processing. We derive robust channel variants of shadow estimation with close-to-optimal performance guarantees and use these as a primitive for partial, compressive and full process tomography as well as the learning of Pauli noise. We discuss applications to the quantum gate engineering cycle, and propose novel methods for the optimization of quantum gates and diagnosing cross-talk.Comment: 10+18 pages, two figures, substantially rewritten (made more intuitive, connected better to common experimental prescriptions, equipped with stronger numerical analysis

    Distal Reoperations after Repair of Acute Type A Aortic Dissection—Incidence, Causes and Outcomes

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    Background and Aim of the Study: In patients with acute type A aortic dissection (A-AAD) whether initial repair should include also aortic arch replacement is still debated. We aimed to assess if extensive aortic repair prevents from reoperations patients with A-AAD. Methods: Outcomes after distal reoperation following repair of A-AAD (n = 285; 1977 to 2018) were analysed in 22 of 226 who underwent ascending aorta/hemiarch replacement (Group 1R) and 7 of 59 who had ascending aorta/arch replacement (Group 2R). Results: Distal reoperation was more common in Group 1R (n = 22) than in Group 2R (n = 0) (p < 0.001) while thoracic endovascular stenting was more frequent in Group 2R (7 vs 3, p < 0.001). Indications for reoperation were pseudoaneurysm at distal anastomosis (n = 4, 18%) and progression of aortic dissection (n = 18, 82%) in Group 1R. Indication for thoracic endovascular stenting was progressive aortic dissection in 3 patients of Group 1R and in 6 of Group 2R. Second reoperation was required in 2 patients from Group 1R (2%) during a mean follow-up of 5 years. Median follow-up was 4 years in Group 1R and 7 years in Group 2R (p = 0.36). Hospital mortality was 14% in Group 1R and 0% in Group 2R (p = 0.3). Actuarial survival is 68 ± 10%, and 62 ± 11% for Group 1R and 100% for Group 2R at 5 and 10 years (p = 0.076). Conclusions: Distal reoperations after A-AAD repair have an acceptable mortality. An extensive initial repair has lower rate of reoperation and better mid-term survival and should be indicated especially for young patients in experienced centers

    Surgical management and outcomes in patients with acute type A aortic dissection and cerebral malperfusion

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    Objective: The study objective was to evaluate the surgical results in patients with acute type A aortic dissection and cerebral malperfusion. Methods: From 2000 to 2019, 234 patients with type A aortic dissection and cerebral malperfusion were stratified into 3 groups: 50 (21%) with syncope (group 1), 152 (65%) with persistent loss of focal neurological function (group 2), and 32 (14%) with coma (group 3). Results were evaluated and compared by univariable and multivariable analyses. Results: Median age was higher in group 1, and incidence of cardiogenic shock was higher in group 3. The femoral artery was the most common cannulation site, whereas the axillary artery was used in 18% of group 1, 30% of group 2, and 25% of group 3 patients (P = .337). Antegrade cerebral perfusion was performed in more than 80% of patients, and ascending aorta/arch replacement was performed in 40% of group 1, 27% of group 2, and 31% of group 3 (P = .21). In-hospital mortality was 18% in group 1, 27% in group 2, and 56% in group 3 (P = .001). Survival at 5 years is 57.0% in group 1, 57.7% in group 2, and 38.7% in group 3 (P = .0005). On multivariable analysis, age, cardiopulmonary bypass time, and group 3 versus group 2 were independent risk factors for mortality, whereas axillary cannulation was a protective factor. Conclusions: Patients with aortic dissection and cerebral malperfusion without preoperative coma showed acceptable mortality, and those with coma had a high in-hospital mortality regardless of the type of brain protection. Overall axillary artery cannulation appeared to be a protective factor

    Chemical Composition of PM10 at Urban Sites in Naples (Italy)

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    Here, we report the chemical characterization and identiïŹcation of the possible sources of particulate matter (fraction PM10) at two different sites in Naples. PM10 concentration and its chemicalcompositionwerestudiedusingthecrustalenrichmentfactor(EF)andprincipalcomponent analysis (PCA). In all of the seasons, the PM10 levels, were signiïŹcantly higher (p 0.8) was obtained between reconstructed mass and gravimetric mass. PCA analysis explained 76% and 79% of the variance in NA01 and NA02, respectively. The emission sources were the same for both sites; but, the location of the site, the different distances from the sources and the presence and absence of vegetation proved the different concentrations and compositions of PM10

    Comparative Analysis of Prothrombin Complex Concentrate and Fresh Frozen Plasma in the Management of Perioperative Bleeding after Coronary Artery Bypass Grafting

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    Background and Aim: Recent studies suggested that prothrombin complex concentrate (PCC) might be more effective than fresh frozen plasma (FFP) to reduce red blood cell (RBC) transfusion requirement after cardiac surgery. The benefits and risks associated with the use of PCC over FFP have been investigated in this study including patients undergoing isolated coronary artery bypass grafting(CABG) from a prospective, multicenter registry. Methods: This is a comparative analysis of 416 patients who received postoperatively FFP and 119 patients who received PCC with or without FFP after isolated CABG. Results: Mixed-effects regression analyses adjusted for multiple covariates and participating centers showed that PCC significantly decreased RBC transfusion (67.2% vs. 87.5%, adjusted OR 0.319, 95%CI 0.136-0.752) and platelet transfusion requirements (11.8% vs. 45.2%, adjusted OR 0.238, 95%CI 0.097-0.566) compared with FFP. The PCC cohort received a mean of 2.7\ub13.7 (median, 2.0, IQR 4) units of RBC and the FFP cohort received a mean of 4.9\ub16.3 (median, 3.0, IQR 4) units of RBC (adjusted coefficient, -1.926, 95%CI -3.357-0.494). The use of PCC increased the risk of KDIGO acute kidney injury (41.4% vs. 28.2%, adjusted OR 2.300, 1.203-4.400), but not of KDIGO acute kidney injury stage 3 (6.0% vs. 8.0%, OR 0.850, 95%CI 0.258-2.796) when compared with the FFP cohort. Conclusions: These results suggest that the use of PCC compared with FFP may reduce the need of blood transfusion after CABG. In view of the observational nature of this study, these results shoul

    Value of Screening Asymptomatic Carotid Artery Stenosis Prior to Coronary Artery Bypass Grafting: Analysis of the E-CABG Registry

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    Background and aim: The aim of this study was to evaluate the prognostic impact of asymptomatic carotid artery stenosis(CAS) in patients undergoing isolated coronary artery bypass grafting(CABG). Methods:Patients from the multicenter, prospective E-CABG registry without history of stroke or transient ischemic attack and screened by duplex ultrasound for CAS before isolated CABG were included in this analysis. Results:Among 2813 patients screened by duplex ultrasound for asymptomatic CAS, 11.1% had a CAS of 50-59%, 6.0% of 60-69%, 3.1% of 70-79%, 1.4% of 80-89%, 0.5% of 90-99%, and 1.1% had carotid occlusion. Postoperative stroke occurred in 25 patients(0.9%). Lesions were bilateral in five patients(25%) and ipsilateral to a CAS 6550% in six patients(30%). In univariate analysis, the severity of CAS was associated with a significantly increased risk of stroke(p<0.0001). In multivariate analysis, a CAS of 90-99%(OR 12.03, 95%CI 1.34-108.23) and the presence of an occluded internal carotid artery(OR 8.783, 95%CI 1.820-42.40) were independent predictors of stroke along with urgency of the procedure, severe-massive bleeding according to the E-CABG classification and the presence of a porcelain ascending aorta. Conclusions: Among patients with asymptomatic CAS, the risk of stroke is significant only in patients with a stenosis 6590%. Since this condition has a low prevalence and when left untreated is associated with a relatively low rate of stroke, preoperative screening of asymptomatic CAS before CABG may not be justified. Instead, avoiding manipulation of diseased ascending aorta and prevention of excessive bleeding may be more effective measures to prevent stroke after CABG
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