On the use of Hidden Markov Processes and auto-regressive filters to incorporate indoor bursty wireless channels into network simulation platforms

In this paper we thoroughly analyze two alternatives to replicate the bursty behavior that characterizes real indoor wireless channels within Network Simulation platforms. First, we study the performance of an improved Hidden Markov Process model, based on a time-wise configuration so as to decouple its operation from any particular traffic pattern. We compare it with the behavior of Bursty Error Model Based on an Auto-Regressive Filter, a previous proposal of ours that emulates the received Signal to Noise Ratio by means of an auto-regressive filter that captures the “memory” assessed in real measurements. We also study the performance of one of the legacy approaches intrinsically offered by most network simulation frameworks. By means of a thorough simulation campaign, we demonstrate that our two models are able to offer a much more realistic behavior, yet maintaining an affordable response in terms of computational complexity.The authors would like to express their gratitude to the Spanish government for its funding in the project “Connectivity as a Service: Access for the Internet of the Future”, COSAIF (TEC2012-38574-C02-01

On the combination of multi-cloud and network coding for cost-efficient storage in industrial applications

The adoption of both Cyber–Physical Systems (CPSs) and the Internet-of-Things (IoT) has enabled the evolution towards the so-called Industry 4.0. These technologies, together with cloud computing and artificial intelligence, foster new business opportunities. Besides, several industrial applications need immediate decision making and fog computing is emerging as a promising solution to address such requirement. In order to achieve a cost-efficient system, we propose taking advantage from spot instances, a new service offered by cloud providers, which provide resources at lower prices. The main downside of these instances is that they do not ensure service continuity and they might suffer from interruptions. An architecture that combines fog and multi-cloud deployments along with Network Coding (NC) techniques, guarantees the needed fault-tolerance for the cloud environment, and also reduces the required amount of redundant data to provide reliable services. In this paper we analyze how NC can actually help to reduce the storage cost and improve the resource efficiency for industrial applications, based on a multi-cloud infrastructure. The cost analysis has been carried out using both real AWS EC2 spot instance prices and, to complement them, prices obtained from a model based on a finite Markov chain, derived from real measurements. We have analyzed the overall system cost, depending on different parameters, showing that configurations that seek to minimize the storage yield a higher cost reduction, due to the strong impact of storage cost

EDU- SALUD. Gestión del conocimiento a través de un repositorio de objetos de Aprendizaje

Introducción: Objeto de aprendizaje (OA): recursos digitales reutilizables, con propósito educativo, constituido al menos tres componentes internos: Contenidos, actividades de aprendizaje y elementos de contextualización. Los OA son utilizados en la enseñanza y el autoaprendizaje. Edu-Salud, sitio Web de código libre, es un repositorio de OA.Objetivo: Elaborar un repositorio de OA, sustentados en web, que facilita el acceso a estos objetos mejorando el auto aprendizaje de los estudiantes de medicina, en la actividad profesional como futuro trabajador de la salud.Método. Se realizó un estudio de desarrollo en la Universidad de Ciencias Médicas de Granma, diagnosticando la utilización de los docentes y estudiantes de los OA. Se utilizaron documentos y analizaron las condiciones para la utilización de OA en la enseñanza, procesando los datos de manera  computarizada, utilizando la estadística descriptiva.Resultados: El Repositorio de OA accesible desde la red de salud donde se accede a la explicación y correcto procedimiento de contenidos médicos.Conclusiones: Se elaboró un repositorio de objetos de aprendizaje, sustentados en web, facilitando el acceso a estos, mejorando el auto aprendizaje de estudiantes, en su actividad profesional como futuro trabajador de la salud.La significación social del problema de investigación, hace necesario darle un mejor uso a las nuevas tecnologías y brindar a los usuarios de la red de salud mejores medios para el aprendizaje y visualización de procedimientos médicos

Adherence to recommendations by infectious disease consultants and its influence on outcomes of intravenous antibiotic-treated hospitalized patients

BACKGROUND: Consultation to infectious diseases specialists (ID), although not always performed by treating physicians, is part of hospital's daily practice. This study analyses adherence by treating physicians to written ID recommendations (inserted in clinical records) and its effect on outcome in hospitalized antibiotic-treated patients in a tertiary hospital in Spain. METHODS: A prospective, randomized, one-year study was performed. Patients receiving intravenous antimicrobial therapy prescribed by treating physicians for 3 days were identified and randomised to intervention (insertion of written ID recommendations in clinical records) or non-intervention. Appropriateness of empirical treatments (by treating physicians) was classified as adequate, inadequate or unnecessary. In the intervention group, adherence to recommendations was classified as complete, partial or non-adherence. RESULTS: A total of 1173 patients were included, 602 in the non-intervention and 571 in the intervention group [199 (34.9%) showing complete adherence, 141 (24.7%) partial adherence and 231 (40.5%) non-adherence to recommendations]. In the multivariate analysis for adherence (R2 Cox=0.065, p=0.009), non-adherence was associated with prolonged antibiotic prophylaxis (p=0.004; OR=0.37, 95%CI=0.19-0.72). In the multivariate analysis for clinical failure (R2 Cox=0.126, p<0.001), Charlson index (p<0.001; OR=1.19, 95%CI=1.10-1.28), malnutrition (p=0.006; OR=2.00, 95%CI=1.22-3.26), nosocomial infection (p<0.001; OR=4.12, 95%CI=2.27-7.48) and length of hospitalization (p<0.001; OR=1.01, 95%CI=1.01-1.02) were positively associated with failure, while complete adherence (p=0.001; OR=0.35, 95%CI=0.19-0.64) and adequate initial treatment (p=0.010; OR=0.39, 95%CI=0.19-0.80) were negatively associated. CONCLUSIONS: Adherence to ID recommendations by treating physicians was associated with favorable outcome, in turn associated with shortened length of hospitalization. This may have important health-economic benefits and stimulates further investigation. TRIAL REGISTRATION: Current Controlled Trials ISRCTN83234896. http://www.controlled-trials.com/isrctn/sample_documentation.asp

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

Angioplastía de circunfleja en paciente con doble arteria descendente anterior tipo IV: Propuesta para actualizar la clasificación de Spindola-Franco

La anatomía normal de las arterias coronarias incluye una serie de variantes respecto a su origen, distribución y recorrido, que hacen que no existan 2 pacientes con coronarias exactamente iguales. La arteria descendente anterior puede tener variantes anatómicas que no afectan el aporte normal de sangre al territorio miocárdico correspondiente. En nuestros 25 años de trabajo y más de 11,000 coronariografías realizadas, sólo habíamos encontrado un paciente con un doble sistema, tipo IV, de la arteria descendente anterior. En este artículo mostramos el caso de una paciente con la anomalía coronaria descrita que presentaba, además, una estenosis severa de la arteria circunfleja que fue tratada exitosamente por vía percutánea. También, se propone una actualización de la clasificación de Spindola-Franco, donde se mantienen los 4 tipos originales y se añaden 7 variantes anatómicas o subtipos

Comportamiento químico de cenizas volantes activadas mediante DRX y FTIR

El presente trabajo establece los comportamientos usuales de los materiales geopoliméricos, usando Difracción de Rayos X (DRX) y Espectroscopía de Infrarrojo (FTIR). Los resultados obtenidos muestran que el geopolímero contiene estructura amorfa pero a su vez diferentes fases cristalinas, principalmente zeolitas, las cuales se relacionan directamente con el activador alcalino utilizado, además los enlaces químicos que aparecen en las bandas de FTIR corresponden a moléculas presentes en los compuestos cristalinos que se manifiestan en los resultados de DRX. Por otro lado se afirma que la ceniza volante fue correctamente activada, debido a la presencia del gel de aluminosilicato sódico hidratado (N-A-S-H) indicada en los espectros de FTIRThis work establishing the behavior of geopolymeric materials using X-ray diffraction (DRX) and Infrared Spectroscopy (FTIR). The results show that the geopolymer containing amorphous structure but turn different crystalline phases, mainly zeolites, which are directly related to the alkaline activator, also the chemical bonds that appear in the FTIR bands correspond to molecules present in the compounds crystalline manifested in the XRD results. Furthermore is stated that the fly ash was correctly activated due to the presence of sodium aluminosilicate gel (N-A-S-H) indicated in FTIR spectra.Peer ReviewedPostprint (published version

Comportamiento químico de cenizas volantes activadas mediante DRX y FTIR

El presente trabajo establece los comportamientos usuales de los materiales geopoliméricos, usando Difracción de Rayos X (DRX) y Espectroscopía de Infrarrojo (FTIR). Los resultados obtenidos muestran que el geopolímero contiene estructura amorfa pero a su vez diferentes fases cristalinas, principalmente zeolitas, las cuales se relacionan directamente con el activador alcalino utilizado, además los enlaces químicos que aparecen en las bandas de FTIR corresponden a moléculas presentes en los compuestos cristalinos que se manifiestan en los resultados de DRX. Por otro lado se afirma que la ceniza volante fue correctamente activada, debido a la presencia del gel de aluminosilicato sódico hidratado (N-A-S-H) indicada en los espectros de FTIRThis work establishing the behavior of geopolymeric materials using X-ray diffraction (DRX) and Infrared Spectroscopy (FTIR). The results show that the geopolymer containing amorphous structure but turn different crystalline phases, mainly zeolites, which are directly related to the alkaline activator, also the chemical bonds that appear in the FTIR bands correspond to molecules present in the compounds crystalline manifested in the XRD results. Furthermore is stated that the fly ash was correctly activated due to the presence of sodium aluminosilicate gel (N-A-S-H) indicated in FTIR spectra.Peer Reviewe