Artificial neural networks as emulators of process-based models to analyse bathing water quality in estuaries

This study aims to provide a method for developing artificial neural networks in estuaries as emulators ofprocess-based models to analyse bathing water quality and its variability over time and space. Themethodology forecasts the concentration of faecal indicator organisms, integrating the accuracy andreliability offield measurements, the spatial and temporal resolution of process-based modelling, andthe decrease in computational costs by artificial neural networks whilst preserving the accuracy of re-sults. Thus, the overall approach integrates a coupled hydrodynamic-bacteriological model previouslycalibrated withfield data at the bathing sites into a low-order emulator by using artificial neural net-works, which are trained by the process-based model outputs. The application of the method to the EoEstuary, located on the northwestern coast of Spain, demonstrated that artificial neural networks areviable surrogates of highly nonlinear process-based models and highly variable forcings. The resultsshowed that the process-based model and the neural networks conveniently reproduced the measure-ments ofEscherichia coli(E. coli) concentrations, indicating a slightly betterfit for the process-basedmodel (R2¼0.87) than for the neural networks (R2¼0.83). This application also highlighted that dur-ing the model setup of both predictive tools, the computational time of the process-based approach was0.78 times lower than that of the artificial neural networks (ANNs) approach due to the additional timespent on ANN development. Conversely, the computational costs of forecasting are considerably reducedby the neural networks compared with the process-based model, with a decrease in hours of 25, 600,3900, and 31633 times for forecasting 1 h, 1 day, 1 month, and 1 bathing season, respectively. Therefore,the longer the forecasting period, the greater the reduction in computational time by artificial neuralnetworks

Estudio de las zonas de acumulación de basuras marinas en el estuario del Pas (Cantabria)

Este trabajo ha sido financiado por la Fundación Biodiversidad del Ministerio de Agricultura y Pesca, Alimentación y Medio Ambiente del Gobierno de España, en el marco del proyecto “Clean LICs

Regulation of cell death receptor S-nitrosylation and apoptotic signaling by Sorafenib in hepatoblastoma cells

Nitric oxide (NO) plays a relevant role during cell death regulation in tumor cells. The overexpression of nitric oxide synthase type III (NOS-3) induces oxidative and nitrosative stress, p53 and cell death receptor expression and apoptosis in hepatoblastoma cells. S-nitrosylation of cell death receptor modulates apoptosis. Sorafenib is the unique recommended molecular-targeted drug for the treatment of patients with advanced hepatocellular carcinoma. The present study was addressed to elucidate the potential role of NO during Sorafenib-induced cell death in HepG2 cells. We determined the intra- and extracellular NO concentration, cell death receptor expression and their S-nitrosylation modifications, and apoptotic signaling in Sorafenib-treated HepG2 cells. The effect of NO donors on above parameters has also been determined. Sorafenib induced apoptosis in HepG2 cells. However, low concentration of the drug (10nM) increased cell death receptor expression, as well as caspase-8 and -9 activation, but without activation of downstream apoptotic markers. In contrast, Sorafenib (10 µM) reduced upstream apoptotic parameters but increased caspase-3 activation and DNA fragmentation in HepG2 cells. The shift of cell death signaling pathway was associated with a reduction of S-nitrosylation of cell death receptors in Sorafenib-treated cells. The administration of NO donors increased S-nitrosylation of cell death receptors and overall induction of cell death markers in control and Sorafenib-treated cells. In conclusion, Sorafenib induced alteration of cell death receptor S-nitrosylation status which may have a relevant repercussion on cell death signaling in hepatoblastoma cells.Instituto de Salud Carlos III PI13/00021Ministerio de Economía y Competitividad BFU2012-32056Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía BIO-0216Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía CTS-6264Consejería de Salud, Junta de Andalucía PI13/ 0002

Development of a methodology to allocate mixing zones of industrial discharges in estuaries

RESUMEN: El objetivo del presente trabajo es proporcionar una metodología escalonada con un grupo de herramientas numéricas seleccionadas y/o desarrolladas con el fin de establecer dónde se requiere una zona de mezcla y determinar su tamaño y aceptabilidad con un nivel de detalle apropiado de acuerdo a su relevancia para cada vertido industrial descargado por boca única situado en un estuario. Esta propuesta puede ser aplicada tanto por los Estados miembros como las industrias a la hora de delimitar zonas de mezcla según lo establecido en la Directiva 2008/105/EC y la Directiva 2013/39/EU. La estructura de la tesis se organiza en seis capítulos de la siguiente manera: • Capítulo 1 Introducción. En este capítulo se introduce al lector los contenidos de todos los demás capítulos de la tesis. En primer lugar, se presentan las motivaciones para llevar a cabo la investigación, explicando su importancia y las razones que llevaron al desarrollo de esta tesis. En segundo lugar, se presenta el objetivo general de la tesis y, por último, se explica su estructura. • Capítulo 2. Estado del Arte. Con el objetivo general en mente, se lleva a cabo una revisión de la literatura con el fin de evaluar los diferentes enfoques metodológicos utilizados en la práctica diaria en todo el mundo, de exponer los temas de actualidad en estuarios (hidrodinámica y mezcla) y, por último, de revisar las herramientas numéricas disponibles utilizadas para estudiar la hidrodinámica y de mezcla de vertidos en estuarios. Esta revisión destaca los puntos fuertes y las deficiencias encontradas en los enfoques actuales y permite la definición de los objetivos específicos de la presente obra. • Capítulo 3. Metodología general. En este capítulo, se describe la metodología escalonada desarrollada mediante el uso de cinco pasos. En el Paso 1, se recopila la información requerida sobre el área de estudio y las descargas de sustancias tóxicas. El Paso 2 identifica la relevancia del vertido en la zona de estudio. A continuación, el Paso 3 evalúa el efecto generado por los vertidos y delimita las zonas de mezcla a partir de un cálculo simplificado, que tiene en cuenta unas condiciones fijas de los forzamientos. El Paso 4 evalúa el efecto generado por las descargas y delimita las zonas de mezcla durante el año más seco de acuerdo con el caudal del río. Finalmente, en el Paso 5, se 'reevalua' el efecto generado por las descargas y se ‘redelimitan’ las zonas de mezcla con base en el caso real de dilución y teniendo en cuenta la variabilidad de los forzamientos ambientales. • Capítulo 4. Herramientas numéricas. En este capítulo, se presenta una revisión de los modelos numéricos usados y de todas las herramientas matemáticas de desarrollo propio que permiten la integración, la transferencia, la comunicación y la representación gráfica de la información requerida y obtenida a lo largo de la metodología expuesta. • Capítulo 5. Resultados: Aplicación en el estuario de Suances. En este capítulo, se ilustra la implementación/aplicación en el estuario de Suances de la metodología desarrollada en el capítulo 3, usando las herramientas numéricas propuestas y descritas en el capítulo 4. • Capítulo 6. Conclusiones y futuras líneas de investigación. Al final del documento, se detallan las conclusiones del presente trabajo junto con algunas propuestas para futuros temas de investigación que pueden complementar el presente estudio y la metodología desarrollada. Por último, se listan todas las aportaciones realizadas por esta tesis.ABSTRACT: The main objective of the present study is to make a step forward in the assessment of mixing zones of single-port industrial discharges in estuaries by developing and implementing a stepped methodology according to the significance of the considered discharge. Thereby, this methodology establishes where a mixing zone is required and determines its size and acceptability for each point discharge based on numerical models and mathematical tools. Thus, in this thesis a “Stepped Approach” has been developed to document the policy decision tree (methodology) that may be adopted by Member States and/or Industries when setting Mixing Zones (MZs) under Directive 2008/105/EC and Directive 2013/39/EU. The structure of the thesis is organized in six chapters as follows: • Chapter 1. Introduction. This chapter has introduced the reader in all other chapters of the thesis. Firstly, the motivations for research, explaining their importance and the reasons that led to the development of this thesis, are displayed. Secondly, the general aim of the thesis is presented and, finally, the organization of this thesis is explained. • Chapter 2. State of the Art. With the general aim in mind, a literature review is carried out in this chapter in order to evaluate the different methodological approaches used in daily practice around the globe, to state the contemporary issues in estuarine physics (hydrodynamics and mixing) and, finally, to gather the available numerical tools used to study estuarine hydrodynamics and mixing. This review highlights the strengths and deficiencies found in current approaches and allows the definition of the final objectives of the present work. • Chapter 3. Overall Methodology. In this chapter, the developed methodology, involving five steps, has been described. In Step 1, we collect the required information about the study area and the toxicant discharges. Step 2 identifies the significance of the discharge or discharges in the study zone. Next, Step 3 evaluates the effect generated by discharges and delimitates MZs from a simplified calculation that takes into account fixed conditions. Step 4 evaluates the effect generated by discharges and delimitates MZs during the driest year according to the river flow. Finally, in Step 5, we ’reevaluate’ the effect generated by discharges and ’redelimitate’ MZs according to a real case of dilution taking into account the variability of the environmental forcings. • Chapter 4. Numerical Tools. In this chapter, a review of the used numerical models and all the self-developed mathematical tools for integrating, transferring, communicating and plotting the required and obtained information along the overall methodology is presented. • Chapter 5. Results: Application to Suances Estuary. The implementation/application to Suances Estuary of the developed methodology in Chapter 3, using the proposed numerical tools described in Chapter 4, is presented. • Chapter 6. Conclusions and Future Research Topics. At the end of the document the conclusions of the present work are presented together with some proposals for future research topics that may complement the present study and the proposed methodology. Lastly, all the contributions made by this thesis were itemized