Elements bàsics de l'àlgebra lineal. Problemes per a la ciència de dades

Postprint (published version

Diseño e implementación de un sistema de control por voz

El presente proyecto final de carrera consiste en el diseño e implementación de un sistema de reconocimiento de voz con una interfaz amigable que permita al usuario un manejo sencillo del sistema, Este sistema tiene como objetivo proporcionar una ayuda a las personas con alguna disminución física. El software elegido para la implementación del sistema el entorno de programación Matlab utilizando las librerias de tratamiento de señales y adquisición de datos. Las razones por las cuales se ha escogido Matlab son las ventajas que presenta respecto a otros entornos algunas de estas ventajas pueden ser: potencia de cálculos, posibilidad de programar una interfaz gráfica fácilmente que permita al usuario ejecutar el programa que sea necesario que tenga conocimientos de programación, etc... Para llevar a cabo la implementación del sistema se han tenido en cuenta las dos principales tecnicas que se utilizan para el reconocimiento del habla que son: reconocimiento utilizando Redes Neuronales artificiales y reconocimento utilizando Modelos Ocultos de Markov

Estimation of wall shear stress using 4D flow cardiovascular MRI and computational fluid dynamics

Electronic version of an article published as Journal of mechanics in medicine and biology, 0, 1750046 (2016), 16 pages. DOI:10.1142/S0219519417500464 © World Scientific Publishing CompanyIn the last few years, wall shear stress (WSS) has arisen as a new diagnostic indicator in patients with arterial disease. There is a substantial evidence that the WSS plays a significant role, together with hemodynamic indicators, in initiation and progression of the vascular diseases. Estimation of WSS values, therefore, may be of clinical significance and the methods employed for its measurement are crucial for clinical community. Recently, four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) has been widely used in a number of applications for visualization and quantification of blood flow, and although the sensitivity to blood flow measurement has increased, it is not yet able to provide an accurate three-dimensional (3D) WSS distribution. The aim of this work is to evaluate the aortic blood flow features and the associated WSS by the combination of 4D flow cardiovascular magnetic resonance (4D CMR) and computational fluid dynamics technique. In particular, in this work, we used the 4D CMR to obtain the spatial domain and the boundary conditions needed to estimate the WSS within the entire thoracic aorta using computational fluid dynamics. Similar WSS distributions were found for cases simulated. A sensitivity analysis was done to check the accuracy of the method. 4D CMR begins to be a reliable tool to estimate the WSS within the entire thoracic aorta using computational fluid dynamics. The combination of both techniques may provide the ideal tool to help tackle these and other problems related to wall shear estimation.Peer ReviewedPostprint (author's final draft

Rapid spectrofluorometric screening of poly-hydroxyalkanoate-producing bacteria from microbial mats

Microbial mat ecosystems are characterized by both seasonal and diel fluctuations in several physicochemical variables, so that resident microorganisms must frequently adapt to the changing conditions of their environment. It has been pointed out that, under stress conditions, bacterial cells with higher contents of poly-hydroxyalkanoates (PHA) survive longer than those with lower PHA content. In the present study, PHA-producing strains from Ebro Delta microbial mats were selected using the Nile red dying technique and the relative accumulation of PHA was monitored during further laboratory cultivation. The number of heterotrophic isolates in trypticase soy agar (TSA) was ca. 107 colony-forming units/g microbial mat. Of these, 100 randomly chosen colonies were replicated on mineral salt agar limited in nitrogen, and Nile red was added to the medium to detect PHA. Orange fluorescence, produced upon binding of the dye to polymer granules in the cell, was detected in approximately 10% of the replicated heterotrophic isolates. The kinetics of PHA accumulation in Pseudomonas putida, and P. oleovorans were compared with those of several of the environmental isolates spectrofluorometry. PHA accumulation, measured as relative fluorescence intensity, resulted in a steady-state concentration after 48 h of incubation in all strains assayed. At 72 h, the maximum fluorescence intensity of each strain incubated with glucose and fructose was usually similar. MAT-28 strain accumulated more PHA than the other isolates. The results show that data obtained from environmental isolates can highly improve studies based on modeling-simulation programs, and that microbial mats constitute an excellent source for the isolation of PHA-producing strains with industrial applications. [Int Microbiol 2006; 9(2):95-102

La construcción mediática de la comunidad política: la prensa en la transición española a la democracia

El artículo analiza el comportamiento y las actitudes adoptadas por la prensa española durante el primer periodo de la transición a la democracia (noviembre de 1975-diciembre de 1978), momento en el que se realizaron los cambios políticos e institucionales más relevantes del proceso. Desde diversas perspectivas se explica el papel que jugaron los principales periódicos, así como las razones que les llevaron al consenso en los temas fundamentales de discusión pública. De esta forma, se constata cómo los medios de comunicación colaboraron de forma decisiva en la construcción de una nueva comunidad política democrática. A través de varios ejemplos de diarios, tomados uno por uno y en conjunto, se explican las especiales características de este interesante caso de colaboración entre poder político y periodismo, incluyendo algunas excepciones como la prensa de extrema derecha y los sectores nacionalistas vascos

Numerical study of the aerodynamics of sound sources in a bass-reflex port

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.The aim of this paper is to study the aerodynamics phenomena of a bass-reflex port that causes noise in the audible frequency range. After discarding structural and mechanical vibration issues, the hypothesis considered is that vortex shedding is the source of the noise. Experimental and numerical evidences of the vortex, an analysis of its noise and the similarities between real and simulated performance are presented. The numerically simulated cases with the original geometry are excited at different frequencies and with modifications of the port geometry. Likewise, the internal performance of an enclosure with a closed port was simulated. The simulations have been performed with axisymmetrical geometries using the open-source OpenFOAM® toolbox. Moreover, experimental measurements were carried out. First, acoustic signal experiments were done to analyse the response of the bass-reflex ports. Secondly, a structure vibration measurement was conducted in order to exclude the cabinet structure vibration as a source of the noise in question. A good agreement was found between numerical and experimental results, especially in the frequency band of the detected noise, i.e. the 1000–1500 Hz range. Despite no remarkable improvement being made with the geometry changes explored, the presented CFD approach has proved a useful and cost-effective tool to address this kind of phenomenon.Peer ReviewedPostprint (published version

Experiences of simulation use in industrial projects

This paper presents experiences obtained from our involvement in the development of industrial simulation projects. Some important, common questions are covered, such as the need to define model behavior using a conceptual model, the problem of choosing the appropriate tool to code the model, and the validation and verification process required. As we will see, the scope of applicability of simulation is broad and the tools are therefore diverse. A clear understanding of the objectives of the simulation, the client’s aims and the resources at our disposal are key issues that often determine the success of a simulation project.Peer ReviewedPostprint (published version

Characterization of CTX-M-14 and CTX-M-15 producing Escherichia coli strains causing neonatal sepsis

Neonatal sepsis is a disease affecting newborns ≤1 month of age with clinical symptoms and positive blood cultures. The number of Escherichia coli strains causing neonatal sepsis resistant to the antibiotics used in the treatment is increasing. In this study, two E. coli strains causing sepsis in neonates of mothers infected with an E. coli strain harboring extended spectrum beta-lactamases were characterized. The blaCTX-M-15 and the blaCTX-M-14 genes were found in an IncFIA and nontypeable transferable plasmids, respectively. In addition, these highly virulent strains belonged to ST705 and ST156 clonal groups, respectively. The presence of strains, which are highly virulent and resistant to ampicillin, gentamicin, and cephalosporins, makes a change in empirical treatment necessary as well as an increase in the surveillance of these infections