Efficient Simulation Tools (EST) for sediment transport in geomorphological shallow flows

Entre los fenómenos superficiales geofísicos y medioambientales, los flujos rápidos de mezclas de agua y sedimentos son probablemente los más exigentes y desconocidos de los procesos movidos por gravedad. El transporte de sedimentos es ubicuo en los cuerpos de agua naturales, como ríos, crecidas, costas o estuarios, además de ser el principal proceso en deslizamientos, flujos de detritos y coladas barro. En este tipo de flujos, el material fluidificado en movimiento consiste en una mezcla de agua y múltiples fases sólidas, que pueden ser de distinta naturaleza como diferentes clases de sedimento, materiales orgánicos, solutos químicos o metales pesados en lodos mineros. El modelado del transporte de sedimentos involucra una alta complejidad debido a las propiedades variables de la mezcla agua-sólidos, el acoplamiento de procesos físicos y la presencia de fenómenos multicapa. Los modelos matemáticos bidimensionales promediados en la vertical ('shallow-type') se construyen en el contexto de flujos superficiales y son aplicables a un amplio rango de estos procesos geofísicos que involucran transporte de sedimentos. Su resolución numérica en el marco de los métodos de Volúmenes Finitos (VF) está controlada por el conjunto de ecuaciones escogido, las propiedades dinámicas del sistema, el acoplamiento entre las variables del flujo y la malla computacional seleccionada. Además, la estimación de los términos fuente de masa y momento puede también afectar la robustez y precisión de la solución. La complejidad de la resolución numérica y el coste computacional de simulación crecen considerablemente con el número de ecuaciones involucradas. Además, la mayor parte de estos flujos son altamente transitorios y ocurren en terrenos irregulares con altas pendientes, requiriendo el uso de una discretización espacial no-estructurada refinada para capturar la complejidad del terreno e incrementando exponencialmente el tiempo computacional. Por tanto, el esfuerzo computacional es uno de los grandes retos para la aplicación de modelos promediados 2D en flujos realistas con grandes escalas espaciales y largas duraciones de evento. En esta tesis, modelos matemáticos superficiales 2D apropiados, algoritmos numéricos de VF robustos y precisos, y códigos eficientes de computación de alto rendimiento son combinados para desarrollar Herramientas Eficientes de Simulación (HES) para procesos medioambientales superficiales involucrando transporte de sedimentos con escalas temporales y espaciales realistas. Nuevas HES capaces de trabajar en mallas estructuradas y no-estructuradas son propuestas para el flujos de lodo/detritos con densidad variable, transporte pasivo en suspensión y transporte de fondo generalizado. Una atención especial es puesta en el acoplamiento entre las variables del sistema y en la integración de los términos fuente de masa y momento. Las propiedades de cada HES han sido cuidadosamente analizadas y sus capacidades demostradas usando tests de validación analíticos y experimentales, así como mediciones en eventos reales.Among the geophysical and environmental surface phenomena, rapid flows of water and sediment mixtures are probably the most challenging and unknown gravity-driven processes. Sediment transport is ubiquitous in environmental water bodies such as rivers, floods, coasts and estuaries, but also is the main process in wet landslides, debris flows and muddy slurries. In this kind of flows, the fluidized material in motion consists of a mixture of water and multiple solid phases which might be of different nature, such as different sediment size-classes, organic materials, chemical solutes or heavy metals in mine tailings. Modeling sediment transport involves an increasing complexity due to the variable bulk properties in the sediment-water mixture, the coupling of physical processes and the presence of multiple layers phenomena. Two-dimensional shallow-type mathematical models are built in the context of free surface flows and are applicable to a large number of these geophysical surface processes involving sediment transport. Their numerical solution in the Finite Volume (FV) framework is governed by the particular set of equations chosen, by the dynamical properties of the system, by the coupling between flow variables and by the computational grid choice. Moreover, the estimation of the mass and momentum source terms can also affect the robustness and accuracy of the solution. The complexity of the numerical resolution and the computational cost of simulation tools increase considerably with the number of equations involved. Furthermore, most of these highly unsteady flows usually occur along very steep and irregular terrains which require to use a refined non-structured spatial discretization in order to capture the terrain complexity, increasing exponentially the computational times. So that, the computational effort required is one of the biggest challenges for the application of depth-averaged 2D models to realistic large-scale long-term flows. Throughout this thesis, proper 2D shallow-type mathematical models, robust and accurate FV numerical algorithms and efficient high-performance computational codes are combined to develop Efficient Simulation Tools (EST's) for environmental surface processes involving sediment transport with realistic temporal and spatial scales. New EST's able to deal with structured and unstructured meshes are proposed for variable-density mud/debris flows, passive suspended transport and generalized bedload transport. Special attention is paid to the coupling between system variables and to the integration of mass and momentum source terms. The features of each EST have been carefully analyzed and their capabilities have been demonstrated using analytical and experimental benchmark tests, as well as observations in real events.<br /

Materiales con propiedades de transporte iónico controladas por intercalación de compuestos oxietilénicos en filosilicatos

Depto. de Química InorgánicaFac. de Ciencias QuímicasTRUEpu

El valor de la universidad

En este extracto del discurso de de apertura del curso 2018-2019 se exponen los retos de la universidad española hoy y se sugieren algunas medidas para afrontarlos

Autoanticuerpos frente a proteínas de la vía alternativa del complemento en enfermedades renales

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Medicina. Fecha de lectura: 13-09-2016La activación del sistema del complemento interviene en el desarrollo de algunas patologías renales en mayor o menor grado. En el caso de las glomerulopatías C3 (C3G) y del síndrome hemolítico urémico atípico (SHUa), alteraciones en la vía alternativa están directamente implicadas en su patogénesis. Estas alteraciones pueden ser congénitas o adquiridas, en forma de autoanticuerpos dirigidos frente a los diversos componentes y reguladores de la vía alternativa. La primera parte de esta tesis se centra en los autoanticuerpos frente al factor H (FH), principal regulador de la vía alternativa. Los autoanticuerpos anti-FH en el SHUa impiden el reconocimiento y la unión de esta proteína a las membranas celulares para regular la activación del complemento en su superficie, siendo éste su principal mecanismo patogénico. Aunque su implicación en la patología está establecida, se sabe poco de las características individuales de estos autoanticuerpos y de su evolución a lo largo del tiempo. Aquí se presenta un estudio detallado de una serie de 19 pacientes con SHUa y autoanticuerpos anti-FH, en muestras obtenidas en algunos casos a lo largo de más de 8 años. Sobre el papel que tienen los anticuerpos anti-FH en las C3G existen menos datos, debido a su menor frecuencia y a que, en ocasiones, aparecen junto a otros autoanticuerpos. Aquí se presenta un caso de una paciente con enfermedad por depósitos densos y autoanticuerpos anti-FH, en la que tras realizar diversos estudios, se determinó que este autoanticuerpo era el causante de la enfermedad renal. Por último, se describen los estudios que se han llevado a cabo en pacientes con lupus eritematoso sistémico (LES), en cuanto a la frecuencia de aparición y la especificidad de estos anticuerpos anti-FH. La segunda parte de la tesis se enfoca en el estudio de autoanticuerpos frente a otras proteínas de la vía alternativa del complemento, en este caso, factor B, factor I, C3 y properdina. Se ha analizado su prevalencia en cohortes de SHUa, C3G y LES; se han estudiado sus efectos en una paciente con nefritis lúpica, en la que se comprobó que estos autoanticuerpos eran capaces de activar la vía alternativa, contribuyendo a su enfermedad.Complement system activation plays an important role in several renal pathologies, including C3 glomerulopathies (C3G) and atypical hemolytic uremic syndrome (aHUS), in which alternative pathway alterations are directly implicated in their pathogenesis. Inherited and acquired factors leading to complement dysregulation have been reported, the latter as autoantibodies directed against alternative pathway components or regulators. The first part of this thesis focuses in autoantibodies against complement factor H (FH), an important alternative pathway regulator. Anti-FH autoantibodies in aHUS block FH’s attachment to endothelial cells and, by doing so, inhibit complement regulation on surfaces. Although the pathogenic role of the autoantibodies is established, little is known about their molecular characteristics and changes over time. Here, a detailed characterization of autoantibodies from 19 aHUS patients is presented, including serial samples from 14 of them, with follow-up times over 8 years in some cases. Despite the fact that anti-FH autoantibodies in C3G were described earlier than in association with aHUS, data about their role in this pathology is limited, because of their low frequency and their simultaneous presence with other autoantibodies in some cases. Here, a patient with dense deposit disease and anti-FH autoantibodies is described. After functional analysis of these autoantibodies, it can be concluded that they are the pathogenic cause of the disease. Finally, studies of frequency and specificity of anti-FH autoantibodies in systemic lupus erytematosus (SLE) patients are presented. The second part of this thesis focuses in autoantibodies directed against other complement alternative pathway proteins, specifically anti-factor B, factor I, C3 and properdin. Frequencies of these autoantibodies in aHUS, C3G and SLE have been analyzed. Autoantibodies recognizing these proteins have been studied in one patient with lupus nephritis, concluding that they cause alternative pathway activation and contribute to the disease

Materiales con propiedades de transporte iónico controladas por intercalación de compuestos oxietilénicos en filosilicatos

Depto. de Química InorgánicaFac. de Ciencias QuímicasTRUEpu

Movement Lawyering During a Crisis: How the Legal System Exploits the Labor of Activists and Undermines Movements

There is increasing recognition that the ableist trope “Justice is Blind” is a decades-long gaslighting of the American public, a distraction from the reality that our entire judicial system has always had a strict adherence to white supremacy. In the United States, the highest court continues to erode civil rights protections that were hard fought by Black Americans, many whose lives were taken during the journey. The legislature has codified laws that simultaneously extract wealth from communities of color and criminalize poverty. And the legal profession is one of the least diverse of any professional industry. Impartiality of legal systems, theory, and praxis is an illusion that we cannot afford to buy-into within our work toward a society with equitable distribution of resources and equal access to wellness and joy. This article aims to highlight how the inequities embedded within the legal system are exacerbated during public crises, and used to exploit the work of Black, indigenous, and other activists of color. The article will shed light on the ways in which traditional litigation strategies, resource allocation, and long-established ethics standards have undermined the work toward liberating historically oppressed communities in the United States. We will provide examples within the movement to defend Black lives, the movement to free our children from cages, and within the hurried push to release people from institutions in the height of the COVID-19 threat. The article will also discuss specific strategies that movement lawyers have successfully employed to shift power away from white supremacist institutions and into the communities with whom we are fighting alongside. We conclude with a call for lawyers and legal workers to think critically about how they leverage power structures within the legal field to work in tandem with movements during a crisis

Spatial variability in the soil water content of a Mediterranean agroforestry system with high soil heterogeneity

Variability of soil water content is known to increase with the size of spatial domain in which measurements are taken. At field scale, heterogeneity in soil, vegetation, topography, water input volume and management affects, among other factors, hydrologic plot behaviour under different mean soil water contents. The present work studies how the spatial variability of soil water content (SWC) is affected by soil type (texture, percentage of stones and the combination of them) in a timber-orientated plantation of cherry tree (Prunus avium) under Mediterranean climatic conditions. The experimental design is a randomized block one with 3 blocks * 4 treatments, based on two factors: irrigation (6 plots irrigated versus 6 plots not irrigated) and soil management (6 plots tillaged versus 6 plots not tillaged). SWC is continuously measured at 25, 50 and 100 cm depth with FDR sensors, located at two positions in each treatment: under tree influence and 2.5 m apart. This study presents the results of the monitoring during 2012 of the 24 sensors located at the 25 cm depth. In each of the measurement point, texture and percentage of stones were measured. Sandy-loam, sandy-clay-loam and loam textures were found together with a percentage of stones ranging from 20 to 70 %. The results indicated that the relationship between the daily mean SWC and its standard deviation, a common procedure used to study spatial variability, changed with texture, percentage of stones and the estimation of field capacity from the combination of both. Temporal stability analysis of SWC showed a clear pattern related to field capacity, with the measurement points of the sandy-loam texture and the high percentage of stones showing the maximun negative diference with the global mean. The high range in the mean relative difference observed ( 75 %), could indicate that the studied plot may be considered as a good field-laboratory to extrapolate results at higher spatial scales. Furthermore, the pattern in the temporal stability of tree growth was clearly related to that one in SWC. Nevertheless, the treatments that represent the mean conditions in growth were not exactly the same than those in SWC, which could be attributable to other characteristics than soil

Los medios digitales y el sindicato de trabajadoras de hogar de la mano de Casa de la mujer Trabajadora - Sintrahin

Es importante mencionar que siempre que se habla de trabajo doméstico se asocia a una mujer y sus diversos roles que deben ejercer ante su familia, sociedad o su entorno laboral y de cómo sus derechos han sido vulnerados desde hace muchos años sin ser valorada su posición en un hogar o en una sociedad, es importante mencionar que en Colombia el 96% de los empleos son ejercidos por mujeres en actividades domésticas y mucho de este % no tienen las condiciones necesarias para ejercerlas es importante llegar a todas la mujeres en diferentes lugares de Colombia aunque por las diversas condiciones es un poco difícil, de tal manera la Casa de la Mujer Trabajadora en especial Sintrahin por medio de campañas digitales en Facebook e Instagram generan alcance en donde pueden llegar a los diversos lugares y en especial conocer las infidencias de sus propias vivencias y de la mano de la dirección de ejecución de proyectos y orientación. Es importante dado lo anteriormente mencionado que la organización también genere estrategias específicas de comunicación para poder generar un engagement mucho más efectivo y el crecimiento de las redes sea más viral.It is important to mention that whenever we talk about domestic work, it is associated with a woman and her various roles that she must perform before her family, society or her work environment and how her rights have been violated for many years without her position being valued in a home or in a society, it is important to mention that in Colombia 96% of jobs are held by women in domestic activities and much of this % do not have the necessary conditions to exercise them, it is important to reach all women in different parts of Colombia although due to the various conditions it is a bit difficult, in such a way the House of Working Women, especially Sintrahin, through digital campaigns on Facebook and Instagram, generate reach where they can reach various places and especially learn about the infidelity of their own experiences and hand in hand with the management of project execution and guidance. Given the aforementioned, it is important that the organization also generate specific communication strategies in order to generate much more effective engagement and the growth of the networks to be more viral