The ANTARES Optical Beacon System

ANTARES is a neutrino telescope being deployed in the Mediterranean Sea. It consists of a three dimensional array of photomultiplier tubes that can detect the Cherenkov light induced by charged particles produced in the interactions of neutrinos with the surrounding medium. High angular resolution can be achieved, in particular when a muon is produced, provided that the Cherenkov photons are detected with sufficient timing precision. Considerations of the intrinsic time uncertainties stemming from the transit time spread in the photomultiplier tubes and the mechanism of transmission of light in sea water lead to the conclusion that a relative time accuracy of the order of 0.5 ns is desirable. Accordingly, different time calibration systems have been developed for the ANTARES telescope. In this article, a system based on Optical Beacons, a set of external and well-controlled pulsed light sources located throughout the detector, is described. This calibration system takes into account the optical properties of sea water, which is used as the detection volume of the ANTARES telescope. The design, tests, construction and first results of the two types of beacons, LED and laser-based, are presented.Comment: 21 pages, 18 figures, submitted to Nucl. Instr. and Meth. Phys. Res.

Clostridium difficile infection among hospitalized HIV-infected individuals: epidemiology and risk factors: results from a case-control study (2002-2013).

BACKGROUND: HIV infection is a risk factor for Clostridium difficile infection (CDI) yet the immune deficiency predisposing to CDI is not well understood, despite an increasing incidence of CDI among such individuals. We aimed to estimate the incidence and to evaluate the risk factors of CDI among an HIV cohort in Italy. METHODS: We conducted a retrospective case-control (1:2) study. Clinical records of HIV inpatients admitted to the National Institute for Infectious Disease "L. Spallanzani", Rome, were reviewed (2002-2013). CASES: HIV inpatients with HO-HCFA CDI, and controls: HIV inpatients without CDI, were matched by gender and age. Logistic regression was used to identify risk factors associated with CDI. RESULTS: We found 79 CDI episodes (5.1 per 1000 HIV hospital admissions, 3.4 per 10000 HIV patient-days). The mean age of cases was 46 years. At univariate analysis factors associated with CDI included: antimycobacterial drug exposure, treatment for Pneumocystis pneumonia, acid suppressant exposure, previous hospitalization, antibiotic exposure, low CD4 cell count, high Charlson score, low creatinine, low albumin and low gammaglobulin level. Using multivariate analysis, lower gammaglobulin level and low serum albumin at admission were independently associated with CDI among HIV-infected patients. CONCLUSIONS: Low gammaglobulin and low albumin levels at admission are associated with an increased risk of developing CDI. A deficiency in humoral immunity appears to play a major role in the development of CDI. The potential protective role of albumin warrants further investigation

Electrospun ZnO/Poly(Vinylidene fluoride-trifluoroethylene) scaffolds for lung tissue engineering

Due to the morbidity and lethality of pulmonary diseases, new biomaterials and scaffolds are needed to support the regeneration of lung tissues, while ideally providing protective effects against inflammation and microbial aggression. In this study, we investigated the potential of nanocomposites of poly(vinylidene fluoride-co-trifluoroethylene) [P(VDF-TrFE)] incorporating zinc oxide (ZnO), in the form of electrospun fiber meshes for lung tissue engineering. We focused on their anti-inflammatory, antimicrobial, and mechanoelectrical character according to different fiber mesh textures (i.e., collected at 500 and 4000 rpm) and compositions: (0/100) and (20/80) w/w% ZnO/P(VDF-TrFE), plain and composite, respectively. The scaffolds were characterized in terms of morphological, physicochemical, mechanical, and piezoelectric properties, as well as biological response of A549 alveolar epithelial cells in presence of lung-infecting bacteria. By virtue of ZnO, the composite scaffolds showed a strong anti-inflammatory response in A549 cells, as demonstrated by a significant decrease of interleukin (IL) IL-1a, IL-6, and IL-8 expression in 6 h. In all the scaffold types, but remarkably in the aligned composite ones, transforming growth factor b (TGF-b) and the antimicrobial peptide human b defensin-2 (HBD-2) were significantly increased. The ZnO/P(VDF-TrFE) electrospun fiber meshes hindered the biofilm formation by Staphylococcus aureus and Pseudomonas aeruginosa and the cell/scaffold constructs were able to impede S. aureus adhesion and S. aureus and P. aeruginosa invasiveness, independent of the scaffold type. The data obtained suggested that the composite scaffolds showed potential for tunable mechanical properties, in the range of alveolar walls and fibers. Finally, we also showed good piezoelectricity, which is a feature found in elastic and collagen fibers, the main extracellular matrix molecules in lungs. The combination of all these properties makes ZnO/P(VDF-TrFE) fiber meshes promising for lung repair and regeneration

First results of the Instrumentation Line for the deep-sea ANTARES neutrino telescope

In 2005, the ANTARES Collaboration deployed and operated at a depth of 2500 m a so-called Mini Instrumentation Line equipped with Optical Modules (MILOM) at the ANTARES site. The various data acquired during the continuous operation from April to December 2005 of the MILOM confirm the satisfactory performance of the Optical Modules, their front-end electronics and readout system. as well as the calibration devices of the detector. The in situ measurement of the Optical Module time response yields a resolution better than 0.5 ns. The performance of the acoustic positioning system, which enables the spatial reconstruction of the ANTARES detector with a precision of about 10 cm, is verified. These results demonstrate that with the full ANTARES neutrino telescope the design angular resolution of better than 0.3 degrees can be realistically achieved

Intelligent non-colorimetric indicators for the perishable supply chain by non-wovens with photo-programmed thermal response

Spoiled perishable products, such as food and drugs exposed to inappropriate temperature, cause million illnesses every year. Risks range from intoxication due to pathogen-contaminated edibles, to suboptimal potency of temperature-sensitive vaccines. High-performance and low-cost indicators are needed, based on conformable materials whose properties change continuously and irreversibly depending on the experienced time-temperature profile. However, these systems can be limited by unclear reading, especially for colour-blind people, and are often difficult to be encoded with a tailored response to detect excess temperature over varying temporal profiles. Here we report on optically-programmed, non-colorimetric indicators based on nano-textured non-wovens encoded by their cross-linking degree. This combination allows a desired time-temperature response to be achieved, to address different perishable products. The devices operate by visual contrast with ambient light, which is explained by backscattering calculations for the complex fibrous material. Optical nanomaterials with photo-encoded thermal properties might establish new design rules for intelligent labels

Discapacidad y Accesibilidad. Reflexiones sobre las barreras en tiempos de distanciamiento social

A partir del aislamiento social de carácter obligatorio dispuesto para todos los habitan-tes del país con el fin de evitar el contagio por el COVID-19 y preservar la vida de las personas como objetivo prioritario, se instala un cambio radical en la rutina en todas las instancias de la vida diaria y, también, en lo personal.En este sentido, las demandas vinculadas a la accesibilidad física, comunicacional, tecnológica, entre otras, así como la perspectiva social de la discapacidad que alude a la generación de apoyos y acciones para remover barreras, hoy resultan indispensables ante el análisis crítico de cómo se transita la pandemia. ¿Qué escenarios vislumbramos en esta coyuntura particular? ¿Qué medidas y políticas podemos identificar en torno al colectivo de personas con discapacidad? ¿Cómo intervienen las organizaciones de las personas con discapacidad en la gestación de estas políticas?Nos interesa problematizar estas ideas tanto en el ámbito educativo como social en general, dando cuenta de las acciones, iniciativas, omisiones y experiencias que hemos observado en este tiempo de transitar la pandemia. También, expondremos algunas de las líneas de trabajo que como Programa de Discapacidad y Accesibilidad de la Facultad de Filosofía y Letras de la Universidad de Buenos Aires hemos llevado adelante.Fil: Fullana, María Florencia. Universidad de Buenos Aires. Facultad de Filosofía y Letras; ArgentinaFil: Gallone, Clara. Universidad de Buenos Aires. Facultad de Filosofía y Letras; ArgentinaFil: Heredia, Marina. Universidad de Buenos Aires. Facultad de Filosofía y Letras; ArgentinaFil: Liceda, Patricia. Universidad de Buenos Aires. Facultad de Filosofía y Letras; ArgentinaFil: Levin, Axel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto de Investigaciones Sociales de América Latina. - Facultad Latinoamericana de Ciencias Sociales. Instituto de Investigaciones Sociales de América Latina; Argentina. Universidad de Buenos Aires; ArgentinaFil: Reznik, Lía B.. Universidad de Buenos Aires. Facultad de Filosofía y Letras; ArgentinaFil: Rusler, Veronica. Universidad de Buenos Aires. Facultad de Filosofía y Letras; Argentin

Impact of concomitant aortic valve replacement in patients with mild-to-moderate aortic valve regurgitation undergoing left ventricular assist device implantation: EUROMACS analysis

Introduction: Left ventricular assist device (LVAD) therapy may lead to an aortic regurgitation, limiting left ventricular unloading and causing adverse events. Whether concomitant aortic valve replacement may improve outcomes in patients with preoperative mild-to-moderate aortic regurgitation remains unclear. Methods: A retrospective propensity score-matched analysis of adult patients with preoperative mild-to-moderate aortic regurgitation undergoing durable LVAD implantation between 01/01/2011 and 30/11/2021 was performed. Patients undergoing concomitant valve surgery other than biological aortic valve replacement were excluded, resulting in 77 with concomitant biological aortic valve replacement and 385 without. Results: Following 1:1 propensity score matching, two groups of 55 patients with and without biological aortic valve replacement were obtained, (mean age 59 ± 11 years, 92% male, 59.1% HeartWare). Aortic regurgitation was mild in 72.7% and 76.4% and moderate in 27.3% and 23.6% in non-replacement and replacement cohorts respectively. The 30-day survival was 89.1% vs. 85.5% (p = 0.59), 1-year survival 69.1% vs. 56.4% (p = 0.19), and 2-year survival 61.8% vs. 47.3% (p = 0.10) in the non-replacement and replacement groups, respectively. After a mean follow-up of 1.2 years, non-replacement patients had a higher incidence of pump thrombosis (11 [20%] vs. 3 [5.5%], p = 0.022) and fewer major bleedings (2 [3.6%] vs. 11 [20%], p = 0.008). Conclusion: Compared with those treated conservatively, patients with mild-to-moderate aortic regurgitation undergoing concomitant aortic valve replacement during LVAD implantation have a similar survival up to 2 years on support. Patients with concomitant valve replacement had a higher risk of bleeding complications but fewer pump thromboses