Comparación de algunos esquemas de volúmenes finitos y de elementos finitos

En este trabajo se comparan dos esquemas numéricos aplicados a la ecuación general del transporte. Se presenta un'esquema lineal de Volúmenes Finitos con función de control lineal a trozos, acoplado con una 8 discretización temporal, y mediante un análisis de Fourier se analiza la estabilidad del esquema para las distintas frecuencias. Se concluye que para ciertos valores de 8, el dominio de estabilidad en un plano Peclet- Courant es más amplio que el correspondiente de Elementos Finitos lineales y que existen zonas del plano Peclet-Courant en las que Volúmenes Finitos tiene un mejor comportamiento. Para ambos tipos de esquemas se evalúa sobre ejemplos modelo la norma infinito; la norma 2 relativa y la norma 1 relativa del vector diferencia entre la solución exacta y la solución aproximada en la aplicación de cada esquema a la resolución de dichos ejemplos que poseen solución analítica conocida.Peer Reviewe

La construcción del Espacio Europeo de Educación Superior y la innovación educativa en la universidad

In the present article, we put forth a reflection about the roll that the renewal of teaching methods used in the learning process for University Degrees must play, within the European Space for Higher Education framework development. We illustrate this, with the activities carried out at the Universidad Politécnica de Madrid during the last four years.En el presente artículo se realiza una reflexión sobre el papel que debe jugar la renovación de los métodos docentes utilizados en el proceso formativo de titulados universitarios en el marco de la construcción del Espacio Europeo de Educación Superior. Lo anterior se ilustra con las actividades que se han venido desarrollando en la Universidad Politécnica de Madrid durante los últimos cuatro años

La gestión del conocimiento en la Universidad Politécnica de Madrid

Based on the uniqueness of its origin and creation, the Polytechnic University of Madrid has developed procedures to identify, manage and share the intellectual assets of its members. The main goal is to exploit its knowledge resources to reach a better position in an increasingly competitive context, with the expectation of attracting good students, getting greater research resources and achieving a higher international standing. This article describes the main activities and achievements that have been developed along different points of view. First, we have to consider the educational resources such as: efforts to improve the integration of new students, the development of generic skills or the implementation of virtual and remote laboratories accessible through the Internet. Second, there are those related to the management of spaces and organizational structures such as: the creation of Educational Innovation Teams or the development of innovation policies. Third, we present the information systems such as: the DataWare- House or the data collected from the application of questionnaires to the staff or the students. Finally and especially, we can’t forget the people as an irreplaceable element in the process of knowledge management. We have tried to maintain a comprehensive approach combining the ability to manage information and resources with the ability of humans to create and innovate.Partiendo de una situación singular en lo referente a su origen y creación, la Universidad Politécnica de Madrid ha desarrollado procedimientos para identificar, ordenar y compartir los activos intelectuales de sus miembros con el fin de explotar sus recursos de conocimiento y competir en un entorno universitario cada vez más competitivo en la captación de buenos estudiantes, recursos de investigación y posición internacional. En este artículo se describen las principales actuaciones y logros que se han desarrollado desde el punto de vista de los recursos educativos (integración de los nuevos estudiantes, desarrollo de competencias genéricas, plataformas experimentales a través de la red y recursos en abierto), espacios y estructura organizativa (Grupos de Innovación Educativa y políticas asociadas), sistemas de información (DataWareHouse y estudios basados en cuestionarios) y especialmente las personas como elemento insustituible en el proceso de gestión del conocimiento. Todo ello con un planteamiento integral que busca la combinación sinérgica de la capacidad de gestión de la información y recursos con la capacidad creativa e innovadora de los seres humanos

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients

Background: Mortality due to COVID-19 is high, especially in patients requiring mechanical ventilation. The purpose of the study is to investigate associations between mortality and variables measured during the first three days of mechanical ventilation in patients with COVID-19 intubated at ICU admission. Methods: Multicenter, observational, cohort study includes consecutive patients with COVID-19 admitted to 44 Spanish ICUs between February 25 and July 31, 2020, who required intubation at ICU admission and mechanical ventilation for more than three days. We collected demographic and clinical data prior to admission; information about clinical evolution at days 1 and 3 of mechanical ventilation; and outcomes. Results: Of the 2,095 patients with COVID-19 admitted to the ICU, 1,118 (53.3%) were intubated at day 1 and remained under mechanical ventilation at day three. From days 1 to 3, PaO2/FiO2 increased from 115.6 [80.0-171.2] to 180.0 [135.4-227.9] mmHg and the ventilatory ratio from 1.73 [1.33-2.25] to 1.96 [1.61-2.40]. In-hospital mortality was 38.7%. A higher increase between ICU admission and day 3 in the ventilatory ratio (OR 1.04 [CI 1.01-1.07], p = 0.030) and creatinine levels (OR 1.05 [CI 1.01-1.09], p = 0.005) and a lower increase in platelet counts (OR 0.96 [CI 0.93-1.00], p = 0.037) were independently associated with a higher risk of death. No association between mortality and the PaO2/FiO2 variation was observed (OR 0.99 [CI 0.95 to 1.02], p = 0.47). Conclusions: Higher ventilatory ratio and its increase at day 3 is associated with mortality in patients with COVID-19 receiving mechanical ventilation at ICU admission. No association was found in the PaO2/FiO2 variation

Clustering COVID-19 ARDS patients through the first days of ICU admission. An analysis of the CIBERESUCICOVID Cohort

Background Acute respiratory distress syndrome (ARDS) can be classified into sub-phenotypes according to different inflammatory/clinical status. Prognostic enrichment was achieved by grouping patients into hypoinflammatory or hyperinflammatory sub-phenotypes, even though the time of analysis may change the classification according to treatment response or disease evolution. We aimed to evaluate when patients can be clustered in more than 1 group, and how they may change the clustering of patients using data of baseline or day 3, and the prognosis of patients according to their evolution by changing or not the cluster.Methods Multicenter, observational prospective, and retrospective study of patients admitted due to ARDS related to COVID-19 infection in Spain. Patients were grouped according to a clustering mixed-type data algorithm (k-prototypes) using continuous and categorical readily available variables at baseline and day 3.Results Of 6205 patients, 3743 (60%) were included in the study. According to silhouette analysis, patients were grouped in two clusters. At baseline, 1402 (37%) patients were included in cluster 1 and 2341(63%) in cluster 2. On day 3, 1557(42%) patients were included in cluster 1 and 2086 (57%) in cluster 2. The patients included in cluster 2 were older and more frequently hypertensive and had a higher prevalence of shock, organ dysfunction, inflammatory biomarkers, and worst respiratory indexes at both time points. The 90-day mortality was higher in cluster 2 at both clustering processes (43.8% [n = 1025] versus 27.3% [n = 383] at baseline, and 49% [n = 1023] versus 20.6% [n = 321] on day 3). Four hundred and fifty-eight (33%) patients clustered in the first group were clustered in the second group on day 3. In contrast, 638 (27%) patients clustered in the second group were clustered in the first group on day 3.Conclusions During the first days, patients can be clustered into two groups and the process of clustering patients may change as they continue to evolve. This means that despite a vast majority of patients remaining in the same cluster, a minority reaching 33% of patients analyzed may be re-categorized into different clusters based on their progress. Such changes can significantly impact their prognosis

Comparación de algunos esquemas de volúmenes finitos y de elementos finitos

En este trabajo se comparan dos esquemas numéricos aplicados a la ecuación general del transporte. Se presenta un'esquema lineal de Volúmenes Finitos con función de control lineal a trozos, acoplado con una 8 discretización temporal, y mediante un análisis de Fourier se analiza la estabilidad del esquema para las distintas frecuencias. Se concluye que para ciertos valores de 8, el dominio de estabilidad en un plano Peclet- Courant es más amplio que el correspondiente de Elementos Finitos lineales y que existen zonas del plano Peclet-Courant en las que Volúmenes Finitos tiene un mejor comportamiento. Para ambos tipos de esquemas se evalúa sobre ejemplos modelo la norma infinito; la norma 2 relativa y la norma 1 relativa del vector diferencia entre la solución exacta y la solución aproximada en la aplicación de cada esquema a la resolución de dichos ejemplos que poseen solución analítica conocida.Peer Reviewe

Arbuscular mycorrhizal root colonization and soil P availability are positively related to agrodiversity in Mexican maize polycultures

In Los Tuxtlas, Mexico, the local Popoluca people maintain the traditional management of their maize agroecosystems. However, it is not known whether the loss of agrodiversity over recent decades has affected mycorrhizal populations, nutrient availability, and crop productivity. This study utilized linear mixed effect models to analyze the relationship between agrodiversity (three, six, and greater than or equal to eight cultivated species) and (a) arbuscular mycorrhizal fungi (AMF) inoculum potential, measured as the most probable number (MPN) of propagules and colonization level, (b) nutrient availability, and (c) aboveground maize productivity. We also investigated the relationship between soil nutrient content and inoculum potential. Soil samples were taken before planting, and during flowering, in the 2009 maize cycle. We found that AMF colonization level of maize roots and P availability increased with planted species richness, but that this effect only occurred at the flowering sampling date. Plots with a higher MPN of propagules presented increased C and NO3 − contents and lower C/N ratio than those with lower MPN of propagules, regardless of agrodiversity. Soils that produced the highest maize root colonization level also featured high P availability and N content. We conclude that decreased agrodiversity in these traditional systems does not significantly affect the soil MPN of propagules, but may have a negative impact on the ability of the mycorrhizal community to colonize maize roots, as well as reducing the availability of P, which is often the most limiting nutrient in tropical soils