Piecewise smooth stationary Euler flows with compact support via overdetermined boundary problems

We construct new stationary weak solutions of the 3D Euler equation with compact support. The solutions, which are piecewise smooth and discontinuous across a surface, are axisymmetric with swirl. The range of solutions we find is different from, and larger than, the family of smooth stationary solutions recently obtained by Gavrilov and Constantin-La-Vicol; in particular, these solutions are not localizable. A key step in the proof is the construction of solutions to an overdetermined elliptic boundary value problem where one prescribes both Dirichlet and (nonconstant) Neumann data

Evaluación de metodologías de control higiénico de superficies alimentarias y adaptación de la PCR en tiempo real como método de control de patógenos

Consultable des del TDXTítol obtingut de la portada digitalitzadaLos programas de control de calidad microbiológica cada vez se aplican más a lo largo de la producción de la cadena alimentaria, siendo uno de ellos el programa de higienización. El propósito de los procedimientos de limpieza y desinfección es la destrucción de los microorganismos alterantes y de los patógenos de las superficies y del medio ambiente, para reducir el riesgo de la contaminación del alimento y evitando así la infección para los consumidores. Por lo tanto, para evaluar un programa de limpieza y desinfección es necesario muestrear las superficies y establecer los niveles residuales de contaminación. Existen diversos métodos para evaluar la contaminación microbiana de las superficies. Sin embargo, no hay un consenso para que un método estándar sea aceptado, debido a las ventajas y desventajas que presentan. Aún así, para la industria alimentaria, cada vez es más importante disponer de sistemas, rápidos y confiables para detectar la contaminación microbiana o incluso la presencia o ausencia de patógenos. En este estudio se usaron diferentes metodologías de control higiénico para vigilar y verificar la contaminación microbiana de superficies alimentarias. Para ello, se eligieron dos instalaciones diferentes con la finalidad de comparar las diferencias en base a los protocolos de limpieza-desinfección. Se evaluaron superficies en una industria alimentos deshidratados con un programa de higienización completo y en un supermercado con un tipo de higienización similar al empleado en el ámbito doméstico. En ambas instalaciones, los mayores recuentos se obtuvieron a partir de los discos, de acero inoxidable, adheridos a las superficies durante una semana y analizados con DEM. La DEM fue la metología más restrictiva. En la industria de alimentos deshidratados, las metodologías que seguidamente detectaron mayores recuentos fueron: la siembra del disco y el análisis de bioluminiscencia para la detección de ATP; mientras que en el supermercado fueron: el método de hisopado convencional y el análisis de bioluminiscencia para la detección de ATP. Conjuntamente, en ambas instalaciones se establecieron límites críticos estandarizados para cada metodología evaluada. En el supermercado, la presencia de patógenos como Salmonella spp., L. monocytogenes y S. aureus (coagulasa positiva) fue negativa y el recuento de enterobacterias obtenido fue muy bajo (<1 UFC/cm2). Además, se adaptó la PCR en tiempo real como método de control de patógenos (Salmonella Typhimurium y L. monocytogenes) en superficies de acero inoxidable en condiciones experimentales. La sensibilidad y eficacia de los kits iQCheck Salmonella e iQCheck Listeria monocytogenes fue demostrada utilizando caldo de soja triptona con 6 g/l de extracto de levadura (TSBYE) y Demi-Fraser (DFraser), respectivamente. Ambos medios de pre-enriquecimiento adicionados con Tween 80 como dispersante bacteriano. La sensibilidad de la PCR en tiempo real fue comparada con el método VIDAS a partir de biofilms y con el cultivo convencional (ISO) a partir de inóculos pequeños. La sensibilidad de la PCR en tiempo real fue mayor en ambos casos. La metodología propuesta podría ser una alternativa válida al método de cultivo convencional (ISO).Microbiological quality control programs are becoming more common throughout all the stages of food production; sanitation is included among these programs. The purpose of cleaning and disinfection procedures is the destruction of spoilage microbes and pathogens from surfaces and the environment, in order to minimize the risk of contamination of food and thus avoiding infection for consumers. In order to assess a program of cleaning and disinfection it is necessary to sample surfaces to detect residual levels of contamination. There are lots of methods to enumerate microbial surface contamination. Nevertheless, there is no consensus on a standard method, because all of them have advantages and disadvantages. Still, for the food industry, the availability of reliable and rapid test systems to determine microbial contamination and the presence or absence of food-borne pathogens is becoming increasingly important. In this study, different hygienic control methodologies were used to assess microbiological contamination of food surfaces. Two different installations were selected to compare the differences based on the protocols of cleaning and disinfection. The evaluation of the surfaces of installations was performed in a dehydrated food manufacturing industry which had a complete sanitation programme and in a supermarket which only used basic sanitation, comparable to household cleaning. For both installations, the highest cell counts were obtained from the stainless steel coupons adhered to the surfaces for one week and analyzed with DEM. This was the most restrictive methodology. Direct spread of stainless steel coupons and bioluminescence assay for ATP determination were the methodologies that then showed higher cell counts in the food industry tested. Whereas, the conventional swab method and bioluminescence assay for ATP determination were the ones detecting higher cell counts at the supermarket. In both locations, standardized critical limits were established for each methodology. In the supermarket, the presence of pathogens such as Salmonella spp., L. monocytogenes and S. aureus (coagulase positive) was negative and Enterobacteriaceae counts was very low (<1 UFC/cm2). Real-time PCR assay was adapted to control food-borne pathogens such as Salmonella Typhimurium and L. monocytogenes on stainless steel surfaces in laboratory conditions. The sensitivity and efficiency of iQCheck Salmonella and iQCheck Listeria monocytogenes kits was demonstrated using triptic soy broth supplemented with 6 g/l of yeast extract (TSBYE) and Demi-Fraser (DFraser), respectively. Both pre-enrichment broths contained Tween 80 as dispersing agent for bacteria. The sensitivity of real-time PCR was tested using biofilms with VIDAS and traditional cultivation method (ISO) with small inocula levels. The sensitivity of real-time PCR was higher in both cases. The tested methodology could be a valid alternative to the conventional cultivation method (ISO)

Deontología del maestro/a de Educación Infantil: Desarrollo de valores humanos con técnicas cooperativas

Los maestros/as de educación infantil entre sus funciones deben priorizar la transmisión de valores prosociales y los principios fundamentales de los Derechos Humanos. Son aprendizajes imprescindibles para la convivencia en comunidad. Principios éticos y valores que respetan la existencia de otros, bien relativos bien universales; se reconoce la existencia de contravalores, conocerlos para evitarlos. Se propone establecer un programa para el descubrimiento de valores que se desarrolle de forma compartida entre maestros/as y familiares muy cercanos. Las técnicas y actividades colaborativas son las más adecuadas, porque realizan entrenamiento de actitudes y comportamientos facilitadores de la convivencia. El objetivo es trabajar, a razón de un valor al mes: Honestidad, Diálogo, Tolerancia, Solidaridad, Justicia, Libertad, Ecología, Responsabilidad y Paz. El código ético propio de la profesión del maestro/a de edades infantiles supone una responsabilidad social, por cuanto se fija la base axiológica y moral de los futuros ciudadanos/as, futuros profesionales.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Quasi-Regression Monte-Carlo Method for Semi-Linear PDEs and BSDEs

[Abstract] In this work we design a novel and efficient quasi-regression Monte Carlo algorithm in order to approximate the solution of discrete time backward stochastic differential equations (BSDEs), and we analyze the convergence of the proposed method. With the challenge of tackling problems in high dimensions we propose suitable projections of the solution and efficient parallelizations of the algorithm taking advantage of powerful many core processors such as graphics processing units (GPUs)

Optimization of the hydrolytic-acidogenic anaerobic digestion stage (55ºC) of sewage sludge : influence of pH and solid content

In conventional single-stage anaerobic digestion processes, hydrolysis is regarded as the rate-limiting step in the degradation of complex organic compounds, such as sewage sludge. Two-stage systems have been proposed to enhance this process. However, so far it is not clear which are the best conditions for a two-stage anaerobic digestion process of sewage sludge, in terms of temperature and hydraulic retention time of each stage. The aim of this work was to determine the optimal conditions for the hydrolytic-acidogenic stage treating real sludge with a high concentration of total solids (40-50 g L⁻¹) and volatile solids (25-30 g L⁻¹), named high concentration sludge. The variables considered for this first stage were: hydraulic retention time (1-4 days) and temperature (55 and 65 °C). Maximum volatile fatty acids generation was obtained at 4 days and 3 days hydraulic retention time for 55 °C and 65 °C, respectively. Consequently, 4 days hydraulic retention time and temperature of 55 °C were set as the working conditions for the hydrolytic-acidogenic stage treating high concentration sludge. The results obtained when operating with high concentration sludge were compared with a low concentration sludge consisting of 17-28 g L⁻¹ total solids and 13-21 g L⁻¹ volatile solids. The effect of decreasing the influent sludge pH, when working at the optimal conditions established, was also evaluated

Increasing biogas production by thermal (70ºC) sludge pre-treatment prior to thermophilic anaerobic digestion

The objective of this work was to investigate the effect of a low temperature pre-treatment (70 °C) on the efficiency of thermophilic anaerobic digestion of primary and secondary waste sludge. Firstly, effect of sludge pre-treatment time (9, 24, 48 and 72 h) was evaluated by the increase in volatile dissolved solids (VDSs), volatile fatty acids (VFAs) and biogas production in thermophilic batch tests. Secondly, semi-continuous process performance was studied in a lab-scale reactor (5 L) working at 55 °C and 10 days solid retention time. The 70 °C pre-treatment showed an initial solubilization effect (increasing VDS by almost 10 times after 9 h), followed by a progressive generation of VFA (from 0 to nearly 5 g L⁻¹ after 72 h). Biogas production increased up to 30% both in batch tests and in semi-continuous experiments. Our results suggest that a short period (9 h) low temperature pre-treatment should be enough to enhance methane production through thermophilic anaerobic digestion of sludge

Inequality and Spatial Convergence in the Mexico City Metropolitan Area, 1989-2010

The analysis of inequality and polarization patterns between by regions of a national economy is central to ascertain their possibilities of future economic development. In this work we study such patterns in municipalities and boroughs of Mexico City Metropolitan Area (Zona Metropolitana de la Ciudad de Mexico, ZMCM). The evolution of inequality and polarization in this important area of Mexico is studied with new proposals of measurement using spatially conditioned indexes and through a dynamic transition analysis. The results confirm that the territorial inequality has grown among the municipalities and boroughs that integrate the ZMCM. Moreover, this phenomenon coincides with an increase of the polarization characterized by the formation of four subgroups or convergence clubs

Vendaje funcional de tobillo

El vendaje funcional es una técnica que intenta mantener, estabilizar, suplir y reforzar unas estructuras biológicas o anatómicas bien definidas. La utilización del vendaje funcional va destinada a permitir la práctica deportiva a pesar de la presencia de una lesión músculo-ligamentosa o para prevenir la aparición de la misma. Esto explica que los vendajes sean un método terapéutico para limitar de forma selectiva un solo grado de libertad de movimiento, lo que permite al deportista continuar su práctica deportiva. Existen dos tipos de vendajes, los adhesivos son los que se asocian con la técnica del vendaje funcional ya que se realizan con mayor frecuencia, y no adhesivos, que son menos específicos y más elásticos, por lo que se relacionan menos con la práctica deportiva