754 research outputs found

    Empleo de isótopos ambientales para discernir la contaminación salina de la cuenca del río Llobregat

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    La formación geológica salina de la comarca del Bages(Barcelona) y su explotación minera en diferentes puntos de la cuenca del Llobregat, influyen en la salinización de los ríos Cardener y Llobregat. La cuenca potásica catalana presenta dos peculiaridades: la formación salina tiene un afloramiento en Cardona, y en algunas zonas las capas de mineral se encuentran cerca de la superficie pero sin aflorar. La geología del terreno puede influir en la salinidad de las aguas de la cuenca por contacto directo con los materiales salinos. La actividad minera de Cardona (cerrada en 1990), Suria,Balsareny y Sallent, genera en la producción del mineral un residuo salino que se acumula en el exterior de las minas formándose las escombreras salinas o «runams». Sus salessolubles se disuelven con la lluvia, y pueden llegar a las aguas superficiales y aguas subterráneas del entorno. El objetivo de este trabajo es evaluar las aportaciones salinas a la cuenca del río Llobregat, separando las de origen natural y las de procedencia antrópica, utilizando la composición isotópica del azufre y del oxigeno del sulfato disuelto en sus aguas. También se cuantifica el origen natural y antrópico de los cloruros que se aportan

    Deducción y generación de modelos de cardinalidad finita

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    Presentamos un procedimiento de tablas semánticas distinto de las estándar en el tratamiento dado a las sentencias de la clase δ, proponiendo modificaciones de esta regla que eviten la generación de ramas infinitas. Las nuevas tablas se revelan útiles para el estudio de lenguajes lógico-formales con semántica finitaria, en particular como procedimiento para definir modelos finitos de sentencias satisfacibles. Mostramos también la aplicabilidad de estos resultados al análisis de la ambigüedad y otros fenómenos en la interpretación del discurso

    Solar drying in the vineyard: a sustainable technology for the recovery of nutrients from winery organic waste

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    The present study describes a pilot-scale experimental validation of a forced-convection greenhouse solar dryer, combined with a biofilter, for controlled atmospheric emissions. This set-up was applied to the dewatering of sewage sludge from a biological plant that treated process wastewater in a commercial Mediterranean winery. Experiments were performed after the harvest, from September onwards, during the peak generation of sludge. The average drying rate during the first 10 days of operation ranged from 1.17 to 2.24 kg m−2 d−1, depending on the measurement method, during which the water content of the sludge was reduced from 90% down to 67%. Biofiltration was quite inefficient against greenhouse gases (methane and dinitrous oxide), and direct emissions during the drying process were on average 57 g CO2-eq m−2 d−1. Ammonia and volatile organic compounds were removed with average efficiencies of 71% and 35%, but ammonia losses through volatilization represented less than 2% of the initial nitrogen content. The sludge was dried further during November, to the lowest possible water content of 14%. Both the intermediate and final sludge dried materials were characterized for their agronomical value as organic fertilizers.info:eu-repo/semantics/acceptedVersio

    Utilidad de la reconstrucción tridimensional con tomografía computarizada en Traumatología y Ortopedia

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    La reconstrucción tridimensional es una nuev a técnica diagnóstica introducida en cirugía ortopédica y traumatología. Está indicada en algunas fracturas de acetábulo, columna y pelvis porque facilita una visión desde diferente s ángulos y en determinadas lesiones congénitas donde es imprescindible una correcta evaluación preoperatoria. Presentamo s dos paciente s con fracturas acetabulares, otro con lesión me - tastásica en columna lumbar y otro con hipoplasia del arco neural de cuarta vértebra lumbar. La reconstrucción tridimensional fue útil para el definitivo diagnóstico en los cuatro pacientes.Three dimensional images is a new technique introduced in orthopaedic surgery and traumatology. It's indicated for some fractures of the acetabulum, spine or pelvic girdle becaus e supply a vision from differents angles and in determinated congenital damage s who is indispensable an accurate evaluation before the surgery. We presented two patients with acetabular fractures, other with a metastasi c tumour in lumbar spine and anothe r with a hipoplasti c neural arch in a lumbar vertebra. The thre e dimensional reconstruction was useful for the definitive diagnostic in the four patients

    Vibrational dynamics of polyatomic molecules in solution: Assignment, time evolution and mixing of instantaneous normal modes

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    Intramolecular vibrational dynamics of polyatomic molecules in solution can be addressed through normal mode analysis based on either equilibrium normal modes (ENMs) or instantaneous normal modes (INMs). While the former offers a straightforward way of examining experimental spectra, the latter provides a decoupled short-time description of the vibrational motions of the molecule. In order to reconcile both representations, a realistic assignment of the INMs in terms of the ENMs is needed. In this paper, we describe a novel method to assign the INMs using the ENMs as templates, which provides a unique relationship between the two sets of normal modes. The method is based specifically on the use of the so-called Min-Cost or Min-Sum algorithm, duly adapted to our problem, to maximize the overlaps between the two sets of modes. The identification of the INMs as the system evolves with time then allows us to quantify the vibrational energy stored in each INM and so monitor the flows of intramolecular vibrational energy within the solute molecule. We also discuss the degree of mixing of the INMs and characterize the way they change with time by means of the corresponding autocorrelation functions. The usefulness of the method is illustrated by carrying out equilibrium molecular dynamics (MD) simulations of the deuterated N-methylacetamide (NMAD) molecule in D2O solution.Fil: Kalstein, Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Centro de Est.e Investigación. Prog.simulación de Proc.moleculares de Relevancia; ArgentinaFil: Fernández Alberti, Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Centro de Est.e Investigación. Prog.simulación de Proc.moleculares de Relevancia; ArgentinaFil: Bastida, Adolfo. Universidad de Murcia; EspañaFil: Soler, Miguel Angel. Universidad de Murcia; EspañaFil: Farag, Marwa H.. Universidad de Murcia; EspañaFil: Zúñiga, J.. Universidad de Murcia; EspañaFil: Requena, Alberto. Universidad de Murcia; Españ

    Anti-glomerular Basement Membrane Glomerulonephritis: A Study in Real Life

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    Glomerulonephritis; Kidney survival; Plasma exchangeGlomerulonefritis; Supervivència renal; Intercanvi de plasmaGlomerulonefritis; Supervivencia renal; Intercambio de plasmaIntroduction: Anti-glomerular basement membrane (anti-GBM) disease is a severe entity with few therapeutic options including plasma exchange and immunosuppressive agents. The aim of this study was to analyze the clinical and pathological features that predict the evolution of end-stage kidney disease (ESKD) and the kidney survival in a cohort of patients with anti-GBM disease with renal involvement in real life. Methods: A retrospective multicentre observational study including 72 patients from 18 nephrology departments with biopsy-proven anti-GBM disease from 1999 to 2019 was performed. Progression to ESKD in relation to clinical and histological variables was evaluated. Results: Creatinine at admission was 8.6 (± 4) mg/dL and 61 patients (84.7%) required dialysis. Sixty-five patients (90.3%) underwent plasma exchange. Twenty-two patients (30.6%) presented pulmonary hemorrhage. Kidney survival was worse in patients with creatinine levels > 4.7 mg/dL (3 vs. 44% p 50% crescents (6 vs. 49%; p = 0.03). Dialysis dependence at admission and creatinine levels > 4.7 mg/dL remained independent significant predictors of ESKD in the multivariable analysis [HR (hazard ratio) 3.13 (1.25–7.84); HR 3 (1.01–9.14); p 4.7 mg/dL and 50.5% crescents had an area under the curve (AUC) of 0.9 (95% CI 0.82–0.97; p < 0.001) and 0.77 (95% CI 0.56–0.98; p = 0.008), respectively. Kidney survival at 1 and 2 years was 13.5 and 11%, respectively. Patient survival at 5 years was 81%. Conclusion: In real life, patients with severe anti-GBM disease (creatinine > 4.7 mg/dL and > 50% crescents) remained with devastating renal prognosis despite plasma exchange and immunosuppressive treatment. New therapies for the treatment of this rare renal disease are urgently needed

    Extracellular Vesicles, the Road toward the Improvement of ART Outcomes

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    Nowadays, farm animal industries use assisted reproductive technologies (ART) as a tool to manage herds’ reproductive outcomes, for a fast dissemination of genetic improvement as well as to bypass subfertility issues. ART comprise at least one of the following procedures: collection and handling of oocytes, sperm, and embryos in in vitro conditions. Therefore, in these conditions, the interaction with the oviductal environment of gametes and early embryos during fertilization and the first stages of embryo development is lost. As a result, embryos obtained in in vitro fertilization (IVF) have less quality in comparison with those obtained in vivo, and have lower chances to implant and develop into viable offspring. In addition, media currently used for IVF are very similar to those empirically developed more than five decades ago. Recently, the importance of extracellular vesicles (EVs) in the fertility process has flourished. EVs are recognized as effective intercellular vehicles for communication as they deliver their cargo of proteins, lipids, and genetic material. Thus, during their transit through the female reproductive tract both gametes, oocyte and spermatozoa (that previously encountered EVs produced by male reproductive tract) interact with EVs produced by the female reproductive tract, passing them important information that contributes to a successful fertilization and embryo development. This fact highlights that the reproductive tract EVs cargo has an important role in reproductive events, which is missing in current ART media. This review aims to recapitulate recent advances in EVs functions on the fertilization process, highlighting the latest proposals with an applied approach to enhance ART outcome through EV utilization as an additive to the media of current ART procedures

    Model Hessian for accelerating first-principles structure optimizations

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    We present two methods to accelerate first-principles structural relaxations, both based on the dynamical matrix obtained from a universal model of springs for bond stretching and bending. Despite its simplicity, the normal modes of this model Hessian represent excellent internal coordinates for molecules and solids irrespective of coordination, capturing not only the long-wavelength acoustic modes of large systems, but also the short-wavelength low-frequency modes that appear in complex systems. In the first method, the model Hessian is used to precondition a conjugate gradients minimization, thereby drastically reducing the effective spectral width and thus obtaining a substantial improvement of convergence. The same Hessian is used in the second method as a starting point of a quasi-Newton algorithm (Broyden's method and modifications thereof), reducing the number of steps needed to find the correct Hessian. Results for both methods are presented for geometry optimizations of clusters, slabs, and biomolecules, with speed-up factors between 2 and 8.Comment: 5 pages, 3 figures submites to Phys. Rev.
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