The fictitious domain method and applications in wave propagation

International audienceThis paper deals with the convergence analysis of the fictitious domain method used for taking into account the Neumann boundary condition on the surface of a crack (or more generally an object) in the context of acoustic and elastic wave propagation. For both types of waves we consider the first order in time formulation of the problem known as mixed velocity-pressure formulation for acoustics and velocity-stress formulation for elastodynamics. The convergence analysis for the discrete problem depends on the mixed finite elements used. We consider here two families of mixed finite elements that are compatible with mass lumping. When using the first one which is less expensive and corresponds to the choice made in a previous paper, it is shown that the fictitious domain method does not always converge. For the second one a theoretical convergence analysis was carried out in [7] for the acoustic case. Here we present numerical results that illustrate the convergence of the method both for acoustic and elastic waves

Experimental study of depth-discharge equations and velocity patterns on vertical slot fishways

Fishways are hydraulic structures that enable fish to go through transverse obstructions to continue their upstream migrations. This paper presents the results of a scale model of a vertical slot fishway. For two different slopes, the performance of two particular designs of vertical slot fishways was studied for a wide range of discharges. Water depths were measured in the almost all the surface of pools. A linear relation between dimensionless discharge and depth of flow, and the same flow patterns for each design were found. With an acoustic Doppler velocimeter (ADV), three-dimensional velocities were measured at several levels in the entire pool to appreciate the structure of the flow. Two different regions in flow patterns were found: a direct flow region characterized for maximum velocities; and a recirculation region, defined by small velocities and horizontal eddies

Sobre el papel del sistema SOS, la recombinación y el intercambio horizontal de genes en la evolución bacteriana

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 06-11-2015El principal objetivo de esta tesis ha sido cuantificar y ampliar el conocimiento sobre los diferentes sistemas evolutivos implicados en el control de la tasa adaptativa en los seres vivos, usando para ello la bacteria modelo E. coli. La mutación, la recombinación y la transferencia horizontal de genes son los mecanismos más prominentes de la evolución bacteriana y todos ellos han sido abordados desde diferentes aproximaciones. En la primera parte de la tesis, se valoró el efecto en el incremento de la mutagénesis que producen ciertos tratamientos antibióticos y si este aumento es dependiente de la presencia de RecA, el activador del sistema SOS. Los resultados sugieren que, al menos ocho antibióticos de los trece ensayados, resultan mutagénicos, en la mayoría de los casos por un mecanismo RecA dependiente. Después se presentan los resultados relacionados con la caracterización funcional de dinF, un gen SOS que probablemente codifica una bomba de expulsión de agentes tóxicos. Se demuestró que su sobreexpresión es capaz de mitigar el estrés oxidativo celular, proteger frente a sales biliares e incluso reducir la tasa de mutación en un mutante mutT. En la tercera sección, se cuantificó la frecuencia de recombinación en una colección de cepas naturales, mediante el uso de una herramienta plasmídica construida ad hoc. Los resultados sugieren que la tasa de recombinación es muy diversa y dinámica en E. coli y que las cepas patógenas son más propensas a la recombinación que sus congéneres comensales. En la última parte, se describe un mecanismo de transferencia horizontal de genes mediado por sepiolita, un material arcilloso presente en el pienso animal. Se discuten, además, las potenciales implicaciones con respecto a la diseminación de resistencia a antibióticos y genes de virulencia en el ganadoThe main objective of this dissertation was to quantify and enlarge the knowledge about the evolutionary systems that control the adaptive rate in all living beings, using the model bacterium E. coli. In this work, we have tackled in different ways the most recognized mechanisms of bacterial evolution, namely mutation, recombination and horizontal gene transfer, In the first part of the dissertation, the increase on mutagenesis that certain antibiotic treatments produce was quantified, assessing whether this increase is dependent on RecA (the SOS response activator). Our results demonstrate that at least eight out of the thirteen antibiotics tested are mutagenic, the most part by a RecA dependent mechanism. Subsequently, the results concerning the characterization of dinF, an SOS gene that probably codes for a toxic compound efflux pump, are presented. We have demonstrated that its overexpression reduces the intracellular oxidative stress levels, protects against bile salts and is able to reduce the mutation rate of a mutT deficient strain. In the third part, the extent of recombination in natural populations of E. coli, using a plasmidic genetic tool built ad hoc was assessed. Our results suggest that recombination can be very diverse and dynamic in the species. Furthermore, pathogenic strains show greater recombinational potential than their commensal counterparts, suggesting a link between virulence and recombination. In the last section, a new horizontal gene transfer mechanism mediated by Sepiolite, a clay material commonly used in animal feed is described. We discuss the potential implications that this transfer could represent in terms of the spread of antibiotic resistance and virulence genesGran parte del trabajo aquí presentado ha sido financiado gracias a los proyectos “Optobacteria: Multianalite automatic system for the detection of drug resistant bacteria” FP7 286998 y (2014) 968889 y REIPI RD12/0015/0012, concedidos al director de esta tesis, el Prof. Jesús Blázque

PRODUCCIÓN Y COMERCIALIZACIÓN DE LA MOJARRA TILAPIA COMO OPCIÓN DE DESARROLLO LOCAL: EL CASO DE: LA COMUNIDAD DE TABASQUILLO 2DA SECCIÓN, MUNICIPIO DE CENTLA, TABASCO, MÉXICO

La pobreza extrema en México, principalmente, aunque no de manera exclusiva, es un fenómeno rural; aunque sólo una cuarta parte de la población mexicana vive en zonas rurales, cerca de dos terceras partes de la población en pobreza extrema habita en estas comunidades, donde en su mayoría viven grupos indígenas que históricamente han sido aislados. Estas comunidades en su mayoría todavía dependen de la agricultura de consumo, sin embargo, cada vez las unidades naturales de producción han sido olvidadas por las nuevas generaciones de campesinos jóvenes. Los proyectos productivos acuícolas pueden ser la opción de acuerdo a la vocación territorial. El caso específico se basa en la ranchería Tabasquillo 2da, Sección, municipio de Centla, Tabasco, México, población clasificada por el INEGI como de alta marginación, es parte integrante de la reserva de la biosfera Pantanos de Centla, declarada por la UNESCO, patrimonio cultural de la humanidad; es en estas zonas rodeadas de riquezas naturales, abundante vegetación y agua dulce paradójicamente habitan población con índices de pobreza extrema. La acuacultura sustentable, es una actividad que ha ido en crecimiento en los últimos años, específicamente el cultivo, engorda y comercialización de la mojarra tilapia,especie que es adaptable al medio cálido húmedo de Tabasco. Se presenta un proyecto basado en la cría de esta especie, como opción de desarrollo local de la comunidad del caso

Luminescent and Scintillating Properties of Lanthanum Fluoride Nanocrystals in Response to Gamma/Neutron Irradiation: Codoping with Ce Activator, Yb Wavelength Shifter, and Gd Neutron Captor

A novel concept for detection and spectroscopy of gamma rays, and detection of thermal neutrons based on codoped lanthanum fluoride nanocrystals containing gadolinium is presented.The trends of colloidal synthesis of the mentioned material, LaF3 co-doped with Ce as the activator, Yb as the wavelength-shifter and Gd as the neutron captor, is reported. Nanocrystals of the mentioned material were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), optical absorption, and photoluminescence spectroscopy. Gamma detection and its potential spectroscopy feature have been confirmed. The neutron detection capability has been confirmed by experiments performed using a 252Cf neutron source.Comment: 5 figures, 16 page

Universal temporal features of rankings in competitive sports and games

Many complex phenomena, from the selection of traits in biological systems to hierarchy formation in social and economic entities, show signs of competition and heterogeneous performance in the temporal evolution of their components, which may eventually lead to stratified structures such as the wealth distribution worldwide. However, it is still unclear whether the road to hierarchical complexity is determined by the particularities of each phenomena, or if there are universal mechanisms of stratification common to many systems. Human sports and games, with their (varied but simplified) rules of competition and measures of performance, serve as an ideal test bed to look for universal features of hierarchy formation. With this goal in mind, we analyse here the behaviour of players and team rankings over time for several sports and games. Even though, for a given time, the distribution of performance ranks varies across activities, we find statistical regularities in the dynamics of ranks. Specifically the rank diversity, a measure of the number of elements occupying a given rank over a length of time, has the same functional form in sports and games as in languages, another system where competition is determined by the use or disuse of grammatical structures. Our results support the notion that hierarchical phenomena may be driven by the same underlying mechanisms of rank formation, regardless of the nature of their components. Moreover, such regularities can in principle be used to predict lifetimes of rank occupancy, thus increasing our ability to forecast stratification in the presence of competition

The role of muscle disuse in muscular and cardiovascular fitness: A systematic review and meta‐regression

We aimed to assess the effects of muscle disuse on muscle strength (MS), muscle mass (MM) and cardiovascular fitness. Databases were scrutinized to identify human studies assessing the effects of muscle disuse on both (1) MM and (2) maximal oxygen uptake (VO2max) and/or MS. Random-effects meta-analysis and meta-regression with initial physical fitness and length of the protocol as a priori determined moderators were performed. We quantitatively analyzed 51 different studies, and the level of significance was set at p < 0.05. Data from the participants in 14 studies showed a decline in both VO2max (SMD: −0.93; 95% CI: −1.27 to −0.58) and MM (SMD: −0.34; 95% CI: −0.57 to −0.10). Data from 47 studies showed a decline in strength (−0.88; 95% CI: −1.04 to −0.73) and mass (SMD: −0.47; 95% CI: −0.58 to −0.36). MS loss was twice as high as MM loss, but differences existed between anatomical regions. Notably, meta-regression analysis revealed that initial MS was inversely associated with MS decline. VO2max and MS decline to a higher extent than MM during muscle disuse. We reported a more profound strength loss in subjects with high muscular strength. This is physiologically relevant for athletes because their required muscular strength can profoundly decline during a period of muscle disuse. It should however be noted that a period of muscle disuse can have devastating consequences in old subjects with low muscular strength.ERDF, Grant PID2022‐140453OB‐I00MICIU/AEI/10.13039/501100011033, Grant PID2022-140453OB-I0

Heterogeneous resource management in energy hubs with self-consumption: Contributions and application example

The energy hub concept and modeling methodology are widely employed tools for solving resource conversionand storage scheduling problems. For instance, industrial clusters might benefit from determining the suitabletime to operate their facilities and to sell electricity to the public power grid, according to legal, economic orenvironmental factors. In this paper, novel elements are introduced in order to more accurately represent realplants and to reduce the amount of decision variables. The major innovation is to consider devices consuming aresource which is not related to the quantity of output produced, by attaching binary decision variables tocertain energy hub outputs. Secondly, a path vector is defined to take into account the flows of resources withinthe system instead of employing a variable for each branch between the components. The third innovationconsists of an additional vector to express the amount of output resources sold from the energy hub, includingconstraints for those resources which are exported and imported through the same medium. An extended energyhub model is first proposed and then applied to a real plant example, including multiple and heterogeneousresources and performing a comparison between days with different demands, weather conditions and electricityprices. The results obtained in the selected scenarios demonstrate a logical operation scheduling, and thereforevalidate the proposed approach

Distributed energy production, control and management: a review of terminology and common approaches

[EN] Over the last few decades, lines of research related to distributed generation and energy management have given rise to the introduction of novel terms referring to continuous production systems and their optimal design, scheduling, control, or modelling. Although some of those ones emerged in the field of power grid analysis and operation, and their later extension towards other energy sources, all they share some common features and hence can be studied from a holistic perspective. In this paper, a review of different ongoing approaches is performed, aimed at offering a global and straightforward view of the stateof-the-art concepts to readers. In order to do so, the most remarkable elements that can be found in publications employed terminology, context, research purpose, mathematical treatment, optimisation strategies, and tools are first defined and characteri-sed. This helped to analyse and classify, in tabular form, some articles selected according to the impact of the journal, their number of cites and the use of certain terms that emerged in the ambit of distributed energy sistems, in order to find possible research gaps in this topic in relation the usual simulation, control, and optimisation techniques. The main conclusions evidence a scarce realisation of applied testing in real-world facilities and a broad neglect of environmental criteria, when it comes to designing and operating this kind of systems.[ES] Durante las últimas décadas, las líneas de investigación relacionadas con la producción distribuida y la gestión energética han dado lugar a la introducción de términos nuevos que aluden a sistemas de producción continuos y su diseño óptimo, planificación, control o modelado. Aunque algunos de estos se han originado en el campo del análisis y operación de la red eléctrica, y su posterior extensión a otras fuentes de energía, todos comparten algunos rasgos comunes que permiten su análisis desde una perspectiva holística. En este artículo, se lleva a cabo una revisión de diferentes enfoques actuales con el objetivo de ofrecer una visión global y sencilla del estado actual de estos conceptos a los lectores. Para ello, se definen primeramente los elementos más significativos presentes en las publicaciones: terminología empleada, contexto, propósito, tratamiento matemático, estrategias de optimización y herramientas. Esto ha servido para realizar una clasificación, en forma de tabla, de artículos más representativos de entre los disponibles en la literatura, así como un análisis comparativo, a fin de dilucidar posibles nichos de investigación en este tema. Las principales concusiones ponen de manifiesto una escasa realización de experimentos en instalaciones reales y una generalizada omisión de criterios medioambientales, cuando se trata del diseño y operación de este tipo de sistemas.Este trabajo ha sido financiado con el Proyecto R+D+i del Plan Nacional DPI2017-85007-R del Ministerio de Ciencia, Innovación y Universidades y Fondos FEDER.Ramos-Teodoro, J.; Rodríguez, F. (2022). Producción, control y gestión distribuida de energía: una revisión de terminología y enfoques habituales. Revista Iberoamericana de Automática e Informática industrial. 19(3):233-253. https://doi.org/10.4995/riai.2022.16497OJS23325319