Viscosity solutions to second order partial differential equations on Riemannian manifolds

We prove comparison, uniqueness and existence results for viscosity solutions to a wide class of fully nonlinear second order partial differential equations $F(x, u, du, d^{2}u)=0$ defined on a finite-dimensional Riemannian manifold $M$. Finest results (with hypothesis that require the function $F$ to be degenerate elliptic, that is nonincreasing in the second order derivative variable, and uniformly continuous with respect to the variable $x$) are obtained under the assumption that $M$ has nonnegative sectional curvature, while, if one additionally requires $F$ to depend on $d^{2}u$ in a uniformly continuous manner, then comparison results are established with no restrictive assumptions on curvature.Comment: Final version: the domain of F in the equation F=0 has been changed in order to get more generality and simplicity in the definitions and assumptions, and several important misprints have been correcte

Ecotoxicología del arsénico: movilización en suelos y aguas, relevancia clínica y métodos de eliminación.

El arsénico por historia ha sido uno de los elementos más usados para envenenar. En la actualidad, también es causa de numerosas intoxicaciones, si bien se producen por contaminación en los suelos y las aguas de consumo humano. En el presente trabajo, se hace una revisión bibliográfica de artículos relacionados con la contaminación por arsénico, cuáles son los factores que determinan una mayor movilización del mismo, los efectos clínicos tras la intoxicación con arsénico, así como los métodos que se usan en la descontaminación de los territorios afectados por grandes cantidades de arsénico

Comparison of the crack pattern in accelerated corrosion tests and in finite elements simulations

In this work, the crack pattern obtained in accelerated corrosion tests is compared to the one obtained in numerical simulations for reinforced steel concrete samples. In the simulations, an expansive joint element is used to simulate the oxide layer behaviour together with finite elements with embedded adaptable cohesive crack to simulate the concrete fracture. In parallel, some samples are artificially corroded imposing constant current and after corrosion they are impregnated with resin containing fluorescein to improve the detection of the cracks. In the paper, the main features of the model and the experimental procedure are described and the crack pattern is analysed. A main crack across the concrete cover is easily seen in both cases, but also secondary cracks are observed after treating the concrete surface, in accordance with the model predictions, which gives further support to the ability of the numerical approach to simulate the real cracking processes

Extensive unfolding of the C-LytA choline-binding module by submicellar concentrations of sodium dodecyl sulphate

We have investigated the stability of the choline-binding module C-LytA against sodium dodecyl sulphate (SDS)-induced unfolding at pH 7.0 and 20 C. A major intermediate with an unfolded N-terminal region accumulates at around 0.75 mM SDS, whereas 2.0 mM SDS was sufficient for a complete unfolding. This might be the first report of a protein being extensively unfolded by submicellar concentrations of SDS, occurring through formation of detergent clusters on the protein surface. All transitions were reversible upon SDS complexation with b-cyclodextrin, allowing the calculation of thermodynamic parameters. A model for the unfolding of C-LytA by SDS is presented and compared to a previous denaturation scheme by guanidine hydrochloride

Does artistic activism change anything? Strategic and transformative effects of arts in anti-coal struggles in Oakland, CA

Altres ajuts: Acord transformatiu CRUE-CSICUnidad de excelencia María de Maeztu CEX2019-000940-MMushrooming opposition to coal mining and transportation in the United States (US) connects with both environmental justice and climate justice movements. Artistic expressions are part of the strategic toolkit of these movements. Art's capacity to foster cultural, cognitive and psychological changes is amply recognized by academics as well as by public in general. Nevertheless, the theoretical question of how art is linked to activist strategies and to socio-spatial transformations in environmental conflicts remains unexplored. This paper contributes to filling this gap by examining the emblematic struggle to stop the construction of a coal-export terminal in Oakland, CA. Our data includes 32 in-depth interviews of activists, artists and legal experts linked to the conflict surrounding this coal-export terminal. Non-participant observation and secondary data collection helped to contextualize the interviews. The results offer a timeline of the movement, a map of artistic expressions, and network analyses around the effects of environmental artistic activism. We demonstrate that creative activism has critical relevance for facilitating engagement, education and outreach of the anti- coal movement. Arts and its spatial impact benefited the movement by expanding its scale and making it more inclusive regarding demographics, including particularly women and youth of color. The use of the arts raised environmental and political awareness and enhanced public participation in decision making. The paper connects the literatures of environmental justice, environmental humanities and human geography. We contribute to the yet underdeveloped dialogue discussing the capacity of art to influence socio-ecological structures and socio-spatial dynamics in cases of environmental justice conflict

Novel Approaches To Fight Streptococcus pneumoniae

Streptococcus pneumoniae affects millions of people worldwide. It is responsible for a wide spectrum of serious illnesses such as pneumonia, meningitis and bacteraemia. The highest rate of pneumococcal disease (and the highest mortality) occurs in young children, as well as in the elderly and the immunocompromised patients. Identification of S. pneumoniae in diagnostic procedures may significantly improve thanks to the descripion of new PCR-derived techniques. Vaccination based on the polysaccharidic capsule, together with benzylpenicillin-derived drugs, constitute the current choices to tackle pneumococcal diseases. However, the wide serotype diversity of S. pneumoniae and the emergence of antibiotic-resistant strains is fostering the development of new methods to fight this microorganism. In this sense, patents documenting the use of novel antibiotics of the fluoroquinolone or tetracycline families have recently been described. Moreover, surface-associated proteins are receiving an increasingly special attention, as they are synthesized by most pneumococcal strains and play an important role in virulence. New patented protein-based vaccines take into consideration these polypeptides. In this article we present the main relevant characteristics of this pathogen and review the most recent methods that have been patented for the prevention, diagnostic and treatment of the pneumococcal diseases

Determination of the bilinear stress-crack opening curve for normal- and high-strength concrete

An improved version of the method proposed to ACI committee 446 and to RILEM TC 187-SOC to determine the fracture parameters of concrete is applied in this study to several mixtures of normal and high-strength concretes. The results are processed with a C++ program developed by the authors to automatise the mathematical operations required to obtain the bilinear softening curve of concrete from the experimental results. Numerical simulations of the tests are also carried out using finite elements with an embedded cohesive crack. The comparison between numerical and experimental results confirms that the experimental and numerical procedures are appropiate for normalstrength concretes and high-strength concretes

Sarcopenia and Malnutrition in the Elderly

Sarcopenia and malnutrition are both commonly occurring conditions in elderly population. As understood today, sarcopenia is a syndrome characterised by progressive and generalised loss of skeletal muscle mass, physical performance and/or strength, whereas malnutrition has been defined as a condition of an imbalance of energy, protein and other nutrients that can cause measurable negative effects. In many populations, malnutrition and sarcopenia are present simultaneously, and they appear clinically through a combination of decreased body weight and nutrient intake, along with a decrease in muscle mass and function. Moreover, malnutrition is one of the key pathophysiological causes of sarcopenia. Both entities result in numerous and substantial negative outcomes to the patients and the healthcare system, including decreased quality of life and functionality and increased healthcare costs, hospitalisation rates, morbidity and mortality. Early identification of sarcopenia would be of great clinical relevance because the loss of muscle mass and strength with ageing can be largely reversed by proper exercise and nutritional intervention. Clinicians should integrate nutritional assessment with sarcopenia screening for optimal evaluation of these two interrelated issues to help improve clinical outcomes

Pautas espaciales en la variabilidad de las precipitaciones españolas

This paper shows a study in depth of the rainfall geographical variability in Spain and Gibraltar. Data used in the analysis were not row but percentage of the deviation from mean, so that periods of high and low precipitation were considered. Two methods were essayed: hierarchical cluster and a grouping of rainfall gauges according to Pearson´s correlation coefficient. The second one was preferred as results from it were geographically significant. The hierarchical cluster was most affected by the structure of data base, with many years of data lack, and it gaves rise to geographical unsatisfactory results. Finally a rainfall regionalization defined fourteen regions represented in three maps, ending with cartography of the fit of each rain gauge series to the mean polygonal line using the determination coefficient (r2).En este artículo se profundiza en el análisis de la variabilidad geográfica de las precipitaciones en España y Gibraltar. No se utilizan los valores crudos de precipitación, sino los porcentajes de variación con respecto a su media aritmética, lo que pone de relieve los períodos de menor y mayor variación pluviométrica. Se han ensayado básicamente dos metodologías: el «cluster» jerárquico y la agrupación de observatorios basándose en el coeficiente de correlación de Pearson. Se opta por este último método, pues arroja mejores resultados. En cambio, el «cluster», muy afectado por la estructura de la base de datos, con muchos años en los que no todas las estaciones registran valores de precipitación, construye unos conglomerados poco significativos geográficamente. Como resultado final, se establece una regionalización pluviométrica en la que se distinguen catorce áreas, reflejándose el proceso regionalizador en tres mapas. Además, se incluye un último resultado cartográfico que muestra el ajuste de las series de precipitación de cada estación con respecto a la poligonal media, mediante el valor del coeficiente de determinación (r2)

A concise review of nanomaterials for drug delivery and release

This review provides an updated vision about the recent developments in the field of drug vectorization using functional nanoparticles and other nanovectors. From a large number of these nanotechnology-based drug delivery systems that emerge nearly every week, only a tiny fraction reaches a pre-clinical or clinical phase study. In this report, we intend to provide contextual information about those nanocarriers and release methods that have shown the best outcomes at in vitro and in vivo experiments, highlighting those with proven therapeutic efficiency in humans. From silica-based porous nanoparticles to liposomes or polymeric nanoparticles, each one of these nanosystems has its advantages and drawbacks. We describe and discuss briefly those approaches that, in our criterion, have provided significant advancements over existing therapies at the in vivo level. This work also provides a general view of those commercially available nanovectors and their specific area of therapeutic action