146 research outputs found

    16^{16}O spectral function from coupled-cluster theory: applications to lepton-nucleus scattering

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    We calculate the 16^{16}O spectral function by combining coupled-cluster theory with a Gaussian integral transform and by expanding the integral kernel in terms of Chebyshev polynomials to allow for a quantification of the theoretical uncertainties. We perform an analysis of the spectral function and employ it to predict lepton-nucleus scattering. Our results well describe the 16^{16}O electron scattering data in the quasi-elastic peak for momentum transfers q500|\mathbf{q}|\gtrapprox500 MeV and electron energies up to 1.2 GeV, extending therefore the so-called first principles approach to lepton-nucleus cross sections well into the relativistic regime. To prove the applicability of this method to neutrino-nucleus cross sections, we implement our 16^{16}O spectral functions in the NuWro Monte Carlo event generator and provide a comparison with recently published T2K neutrino data.Comment: 12 pages, 9 figure

    Continuous flow adsorption of phenolic compounds from olive mill wastewater with resin XAD16N: life cycle assessment, cost\u2013benefit analysis and process optimization

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    BACKGROUND: Olive mill wastewaters (OMWs) represent a major environmental concern due to their high organic load and phytotoxic activity. The selective recovery of phenolic compounds (PCs) from OMW is promising, thanks to the antioxidant and antimicrobial properties of PCs. The goal of this work was to perform a life cycle assessment (LCA) and cost\u2013benefit analysis (CBA) of a full-scale process of PC adsorption/desorption on resin Amberlite XAD16N. The industrial process was designed on the basis of laboratory tests aimed at performing a preliminary process optimization. RESULTS: Adsorption tests were conducted at different velocities in a 1.8-m column packed with XAD16N. The optimal superficial velocity and retention time (2.78 m h \u20131 and 0.56 h) allowed the attainment of satisfactory performances in terms of resin operating capacity (0.46), PC adsorption yield (0.92), PC mass fraction in the sorbed product (0.50 g PC /g VS ) and specific antioxidant activity (3\u20136 g ascorbic acid /g PC ). Six consecutive adsorption/desorption cycles, operated with the same resin load, resulted in stable process performances. The LCA indicated that the environmental impact of the process could be decreased markedly through the addition of an anaerobic digestion step for the production of irrigation-quality water and fertilizers from the dephenolized OMW. The PC market price required for the generation of a positive business case resulted relatively low (\u20ac1.7\u201313.5 kg PC\u20131 ). CONCLUSION: The results indicate that the proposed PC adsorption/desorption technology, if integrated with an anaerobic digestion step, represents a promising solution for the treatment and valorization of OMW, a major agro-industrial waste in Mediterranean countries

    On the Accuracy of Hyperspherical Harmonics Approaches to Photonuclear Reactions

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    Using the Lorentz Integral Transform (LIT) method we compare the results for the triton total photodisintegration cross section obtained using the Correlated Hyperspherical Harmonics (CHH) and the Effective Interaction Hyperspherical Harmonics (EIHH) techniques. We show that these two approaches, while rather different both conceptually and computationally, lead to results which coincide within high accuracy. The calculations which include two- and three-body forces are of the same high quality in both cases. We also discuss the comparison of the two approaches in terms of computational efficiency. These results are of major importance in view of applications to the much debated case of the four-nucleon photoabsorption.Comment: 12 pages, 3 figure

    The six-nucleon Yakubovsky equations for 6He

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    The six-nucleon problem for the bound state is formulated in the Yakubovsky scheme. Hints for a numerical implementation are provided.Comment: 25 pages, 0 figure

    Helium halo nuclei from low-momentum interactions

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    We present ground-state energies of helium halo nuclei based on chiral low-momentum interactions, using the hyperspherical-harmonics method for 6He and coupled-cluster theory for 8He, with correct asymptotics for the extended halo structure.Comment: 7 pages, 3 figures, contribution to ENAM08 conference proceedings, added results, to appear in EPJ

    Epidemiology and Outcomes of Bloodstream Infections in HIV-Patients during a 13-Year Period

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    No data on antibiotic resistance in bloodstream infection (BSI) in people living with HIV (PLWH) exist. The objective of this study was to describe BSI epidemiology in PLWH focusing on multidrug resistant (MDR) organisms. A retrospective, single-center, observational study was conducted including all positive blood isolates in PLWH from 2004 to 2017. Univariable and multivariable GEE models using binomial distribution family were created to evaluate the association between MDR and mortality risk. In total, 263 episodes (299 isolates) from 164 patients were analyzed; 126 (48%) BSI were community-acquired, 137 (52%) hospital-acquired. At diagnosis, 34.7% of the patients had virological failure, median CD4 count was 207/μL. Thirty- and 90-day mortality rates were 24.2% and 32.4%, respectively. Thirty- and 90-day mortality rates for MDR isolates were 33.3% and 46.9%, respectively (p < 0.05). Enterobacteriaceae were the most prevalent microorganisms (29.8%), followed by Coagulase-negative staphylococci (21.4%), and S. aureus (12.7%). In BSI due to MDR organisms, carbapenem-resistant K. pneumoniae and methicillin-resistant S. aureus were associated with mortality after adjustment for age, although this correlation was not confirmed after further adjustment for CD4 < 200/μL. In conclusion, BSI in PLWH is still a major problem in the combination antiretroviral treatment era and it is related to a poor viro-immunological status, posing the question of whether it should be considered as an AIDS-defining event

    Diseño y prueba de un robot móvil con tres niveles de complejidad para la experimentación en robótica

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    Un robot móvil (llamado UV-BOT), fue diseñado en la Universidad del Valle para la experimentación en robótica y puede ser usado por personas con o sin conocimiento en robótica. UV-BOT es un robot diferencial y para uso en interiores; cuenta con sensores de proximidad, detección de luz, localización y comunicaciones, y su velocidad es controlada mediante dos controladores PI, uno en cada rueda. El firmware del robot fue diseñado usando un micro-núcleo de tiempo real conocido como FreeRTOS, que soporta tres niveles de complejidad, los cuales poseen un conjunto de funcionalidades desde el punto de vista de percepción, movilidad, comuno en la Universidad del Valle para la experimentación en robótica y puede ser usado por personas con o sin conocimiento en robótica. UV-BOT es un robot diferencial y para uso en interiores; cuenta con sensores de proximidad, detección de luz, localización y comunicaciones, y su velocidad es controlada mediante dos controladores PI, uno en cada rueda. El firmware del robot fue diseñado usando un micro-núcleo de tiempo real conocido como FreeRTOS, que soporta tres niveles de complejidad, los cuales poseen un conjunto de funcionalidades desde el punto de vista de percepción, movilidad, comunicación, programación y disponibilidad de demos. Estas funcionalidades son empleadas por la interfaz de usuario para programar el robot gráficamente (nivel básico), usando XML (nivel intermedio) o C (nivel avanzado). En su nivel avanzado, el robot soporta la programación orientada a comportamientos. Estos comportamientos fueron utilizados para realizar las pruebas de desempeño del robot móvil. Como resultado de estas pruebas, se encontró que el sistema de localización de UVBOT muestra una incertidumbre promedio de 17 cm. Los comportamientos de retorno (por posición y luz) y evasión de obstáculos muestran errores promedio de 15 y 12 cm, respectivamente. De este modo, con UV-BOT se pueden implementar exitosamente tareas básicas en robótica cooperativa

    Metabolic-Associated Fatty Liver Disease Is Highly Prevalent in the Postacute COVID Syndrome.

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    Background: A proposal has recently been advanced to change the traditional definition of nonalcoholic fatty liver disease to metabolic-associated fatty liver disease (MAFLD), to reflect the cluster of metabolic abnormalities that may be more closely associated with cardiovascular risk. Long coronavirus disease 2019 (COVID-19) is a smoldering inflammatory condition, characterized by several symptom clusters. This study aims to determine the prevalence of MAFLD in patients with postacute COVID syndrome (PACS) and its association with other PACS-cluster phenotypes. Methods: We included 235 patients observed at a single university outpatient clinic. The diagnosis of PACS was based on ≥1 cluster of symptoms: respiratory, neurocognitive, musculoskeletal, psychological, sensory, and dermatological. The outcome was prevalence of MAFLD detected by transient elastography during the first postdischarge follow-up outpatient visit. The prevalence of MAFLD at the time of hospital admission was calculated retrospectively using the hepatic steatosis index. Results: Of 235 patients, 162 (69%) were men (median age 61). The prevalence of MAFLD was 55.3% at follow-up and 37.3% on admission (P &lt; .001). Insulin resistance (odds ratio [OR] = 1.5; 95% confidence interval [CI], 1.14-1.96), body mass index (OR = 1.14; 95% CI, 1.04-1.24), and the metabolic syndrome (OR = 2.54; 95% CI, 1.13-5.68) were independent predictors of MAFLD. The number of PACS clusters was inversely associated with MAFLD (OR = 0.86; 95% CI, .76-0.97). Thirty-one patients (13.2%) had MAFLD with no other associated PACS clusters. All correlations between MAFLD and other PACS clusters were weak. Conclusions: Metabolic-associated fatty liver disease was highly prevalent after hospital discharge and may represent a specific PACS-cluster phenotype, with potential long-term metabolic and cardiovascular health implications
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