Modeling long term Enhanced in situ Biodenitrification and induced heterogeneity in column experiments under different feeding strategies

Enhanced In situ Biodenitrification (EIB) is a capable technology for nitrate removal in subsurface water resources. Optimizing the performance of EIB implies devising an appropriate feeding strategy involving two design parameters: carbon injection frequency and C:N ratio of the organic substrate nitrate mixture. Here we model data on the spatial and temporal evolution of nitrate (up to 1.2 mM), organic carbon (ethanol), and biomass measured during a 342 day-long laboratory column experiment (published in Vidal-Gavilan et al., 2014). Effective porosity was 3% lower and dispersivity had a sevenfold increase at the end of the experiment as compared to those at the beginning. These changes in transport parameters were attributed to the development of a biofilm. A reactive transport model explored the EIB performance in response to daily and weekly feeding strategies. The latter resulted in significant temporal variation in nitrate and ethanol concentrations at the outlet of the column. On the contrary, a daily feeding strategy resulted in quite stable and low concentrations at the outlet and complete denitrification. At intermediate times (six months of experiment), it was possible to reduce the carbon load and consequently the C:N ratio (from 2.5 to 1), partly because biomass decay acted as endogenous carbon to respiration, keeping the denitrification rates, and partly due to the induced dispersivity caused by the well developed biofilm, resulting in enhancement of mixing between the ethanol and nitrate and the corresponding improvement of denitrification rates. The inclusion of a dual-domain model improved the fit at the last days of the experiment as well as in the tracer test performed at day 342, demonstrating a potential transition to anomalous transport that may be caused by the development of biofilm. This modeling work is a step forward to devising optimal injection conditions and substrate rates to enhance EIB performance by minimizing the overall supply of electron donor, and thus the cost of the remediation strategy.Peer ReviewedPostprint (author's final draft

Estimación por intervalos

Presentación de estimación por intervalos y cálculo del tamaño muestral en poblaciones infinitasParcialmente financiado por el PIE13-02

Cuestionario de estimación por intervalos

Parcialmente financiado por el PIE13-02

Cuestionario de estimación puntual

Parcialmente financiado por el PIE13-02

Cuestionario de distribuciones en el muestreo

Parcialmente financiado por el PIE13-02

Análisis de eficiencia productiva de revistas de economía cuantitativa a través del análisis de fronteraestocástica utilizando datos de pane

The main goal of a scientific journal is to diffuse new knowledge. The number of citations received by a journal can be considered as a measure of this objective and, in turn, as a measure of productivity in relation to the production process in which the journals are involved. In order to assess this production process, in this paper econometric models using data panel are employed to obtain measures of efficiency for those journals belonging simultaneously to the areas of ¿economics¿ and ¿social science, mathematical methods¿ in the Web of Science database. This efficiency is measured in terms of the distance between the actual production of the journals and their estimated maximum achievable number of citations based on their available resourcesEl principal objetivo de una revista científica es difundir nuevo conocimiento. El número de citas recibidas por una revista se puede considerar como una medida de este objetivo y, a su vez, como una medida de productividad en relación al proceso de producción en el que las revistas están involucradas. Para evaluar este proceso de producción, en este artículo se emplean modelos econométricos que usan datos de panel para obtener medidas de eficiencia para aquellas revistas que pertenecen simultáneamente a las áreas ¿economics¿ y ¿social science, mathematical methods¿ en la base de datos Web of Science. Esta eficiencia se mide en términos de la distancia entre la producción real de las revistas y su número de citas máximo alcanzable estimado en base a sus recursos disponibles.Universidad Pablo de Olavid

Fibrous dysplasia of the temporal bone secondary to ear surgery: A case report

Introduction: In this report, we describe the clinical course, diagnostic features and management of a patient with fibrous dysplasia of the temporal bone 7 years after middle ear surgery on the same side. Case presentation: A 16-year-old Caucasian girl presented to our hospital with a growing bone lesion in the roof of the left temporal bone. She had undergone a previous tympanoplasty at 7 years of age because of a cholesteatoma. At the time of that first surgery, no radiological or histological signs indicated a bone disorder. A computed tomographic scan of the temporal bone showed a lesion with rarefaction areas and lytic images inside that affected the roof of the cavity to the tegmen tympani without alterations in the inner ear. A surgical revision of the ear cavity was performed by resecting the lesion and regularizing the cavity. The histopathologic study confirmed fibrous dysplasia. The patient progressed satisfactorily after surgery with no evidence of recurrence. Conclusion: To the best of our knowledge, this is the first report of fibrous dysplasia of the temporal bone secondary to ear surger

The Molecular Biology of Vestibular Schwannomas and Its Association with Hearing Loss: A Review

Hearing loss is the most common symptom in patients with vestibular schwannoma (VS). In the past, compressive mechanisms caused by the tumoral mass and its growth have been regarded as the most likely causes of the hearing loss associated with VS. Interestingly, new evidence proposes molecular mechanisms as an explanation for such hearing loss. Among the molecular mechanisms proposed are methylation of TP73, negative expression of cyclin D1, expression of B7-H1, increased expression of the platelet-derived growth factor A, underexpression of PEX5L, RAD54B, and PSMAL, and overexpression of CEA. Many molecular mechanisms are involved in vestibular schwannoma development; we review some of these mechanisms with special emphasis on hearing loss associated with vestibular schwannoma

Estimación puntual

Presentación de las propiedades de los estimadoresParcialmente financiado por el PIE13-02

Distribuciones en el muestreo. Introducción a la inferencia estadística.

Presentación de los conceptos introductorios a la inferencia estadísticaParcialmente financiado por el PIE13-02