Discrete/finite element modelling of rock cutting with a TBM disc cutter

The final publication is available at Springer via http://dx.doi.org/10.1007/s00603-016-1133-7This paper presents advanced computer simulation of rock cutting process typical for excavation works in civil engineering. Theoretical formulation of the hybrid discrete/finite element model has been presented. The discrete and finite element methods have been used in different subdomains of a rock sample according to expected material behaviour, the part which is fractured and damaged during cutting is discretized with the discrete elements while the other part is treated as a continuous body and it is modelled using the finite element method. In this way, an optimum model is created, enabling a proper representation of the physical phenomena during cutting and efficient numerical computation. The model has been applied to simulation of the laboratory test of rock cutting with a single TBM (tunnel boring machine) disc cutter. The micromechanical parameters have been determined using the dimensionless relationships between micro- and macroscopic parameters. A number of numerical simulations of the LCM test in the unrelieved and relieved cutting modes have been performed. Numerical results have been compared with available data from in-situ measurements in a real TBM as well as with the theoretical predictions showing quite a good agreement. The numerical model has provided a new insight into the cutting mechanism enabling us to investigate the stress and pressure distribution at the tool–rock interaction. Sensitivity analysis of rock cutting performed for different parameters including disc geometry, cutting velocity, disc penetration and spacing has shown that the presented numerical model is a suitable tool for the design and optimization of rock cutting process.Peer ReviewedPostprint (published version

Modulatory effects mediated by metabotropic glutamate receptor 5 on lateral geniculate nucleus relay cells

[Abstract] Glutamate is thought to be the excitatory neurotransmitter in the lateral geniculate nucleus (LGN) of the cat, mediating visual transmission from the retina via ionotropic receptors of both d,l-α-amino-3-hydroxy-5-α-methyl-4-isoxazolepropionate and N-methyl-d-aspartate subtypes. Moreover, glutamate also exerts an important modulatory influence on LGN cells, where metabotropic glutamate receptors (mGluRs) seem to play a crucial role. Here we show in anesthetized adult cats that iontophoretic application of the specific mGluR5 antagonist 2-methyl-6-(phenylethynyl)-pyridine (MPEP) produced two, distinctly different, effects on LGN neurons. Visual responses to flashing spots and drifting gratings were attenuated (decreased by an average of 59%) in 13 of 23 of the cells but augmented (increased by an average of 60%) in 10 of 23 of the cells. Further, in each case when the specific mGluR5 agonist (R,S)-2-chloro-5-hydroxyphenylglycine was applied, the effects obtained were the opposite to those of MPEP. Data obtained in a second group of experiments to determine a possible interaction between mGluR5 blockade by MPEP and glutamate ionotropic receptors show that, in the majority of neurons (11 of 15, 73%), the MPEP-mediated effects seem to be independent of N-methyl-d-aspartate and d,l-α-amino-3-hydroxy-5-α-methyl-4-isoxazolepropionate receptor activity. Our results demonstrate a physiological role for mGluR5 in controlling retinal input and show, in vivo, a more intricate scenario than previously suggested, highlighting the complexity of metabotropic receptor interactions with excitatory and inhibitory elements in the thalamus.Ministerio de Ciencia y Tecnología; BFI2002-320

Synergistic effects of applying static magnetic fields and diazepam to improve EEG abnormalities in the pilocarpine epilepsy rat model

[Abstract] The lithium-pilocarpine rat model is a well-known model of temporal epilepsy. Recently we found that transcranial static magnetic stimulation (tSMS) delay and reduce the signs of EEG in this model. We aim to test the effect of combining the therapeutic action of tSMS and diazepam, a drug used to treat status epilepticus. We induce epilepsy in 12 Sprague-Dawley rats. Animals were classified as "magnet" when a magnetic neodymium cylinder was placed over the skull or "control" when a stainless-steel replica was used. Diazepam was injected 60-min after the second doses of pilocarpine injection. We found a reduction in the number of spikes/minute for magnet condition compared with sham condition, reaching significance at 60 min after diazepam injection. The Root-Mean-Square shown a significant reduction in magnet animals compared with those receiving diazepam (Tukey's-test 30 and 60 min after diazepam injection, p < 0.01; 40 and 50 min after diazepam injection, p < 0.05). Furthermore, the power spectrum analysis shown a reduction in delta, theta, alpha and beta bands, on the diazepam + magnet animals compared to the diazepam + sham group. Analysis of high-frequency oscillations revealed an increased in the ripples due to pilocarpine being reduced by diazepam. Our results demonstrate that application of tSMS previously to diazepam potentiates the effect of the drug by reducing the electroencephalographic pattern associated with epileptiform discharges. We suggest a new synergistic cooperation between pharmacology and neuromodulation as a future treatment for epilepsy.Instituto de Salud Carlos III; PI21/00151Xunta de Galicia; ED431C 2022/0

Tecnología y creatividad en la mejora de la docencia universitaria

Este artículo presenta una propuesta de transformación de la formación continua basada en redes sociales a partir de la exploración de la noción de creatividad aplicada de Herrán, con la que analizar las prácticas de enseñanza en educación superior. Se trata de un proceso de formación seguido de otro de investigación – acción con ayuda de las TIC, un ciclo de 3 pasos para repensar la práctica. Los docentes participantes modificaron sus programaciones incluyendo creatividad, desarrollaron proyectos de este tenor con sus estudiantes y lo compartieron en una red con otros docentes. De resultas de todo ello, se extrajeron algunas fortalezas y debilidades del proceso, y lecciones para reformularlo.This article presents a proposal to transform continuing education based on social networks from the exploration of the Herrán´s notion of creativity applied, with which to analyze teaching practices in higher education. This is a process of training followed by another action - research with the help of ICT, a cycle of 3 steps to rethink the practice. The participating teachers changed their schedules including creativity, develop projects in this vein with his students and shared on a network with other teachers. As a result of this, we extracted some strengths and weaknesses of the process, and lessons for redrafting.Este artigo apresenta uma proposta de transformação da formação contínua baseada em redes sociais a partir da exploração da noção de criatividade aplicada de Herrán, com a que analisar as práticas de ensino em educação superior. Trata-se de um processo de formação seguido de outro de investigação – ação com ajuda das TICs, um ciclo de 3 passos para repensar a prática. Os docentes participantes modificaram suas programações incluindo criatividade, desenvolveram projetos deste tenor com seus estudantes e o compartilharam numa rede com outros docentes. De resultas de tudo isso, extraíram-se algumas fortalezas e debilidades do processo, e lições para reformularlo

Psychophysiological studies of unattended information processing

[Abstract] The article describes the general methods and some of the results obtained in the Psychophysiology Laboratory of the University of La Coruña. The paper covers our research on the Simon effect and accessory effect, although it is not a review of the literature. The research strategy we followed is built around the use of lateralized motor potentials recorded from scalp. These measures allow observing the way responses are selected and when they are selected, providing an invaluable tool to study response interference and to split reaction time into two halves. The research on the Simon effect concludes that interference during response selection is critical in the Simon effect but it is dubious whether this process should be considered as automatic and stimulus-driven, as is widely accepted. The experiments with the accessory effect indicate that facilitation is produced before response selection is over, which ends a long controversy about the locus of the accessory effect.[Resumen] El artículo describe el método y algunos de los resultados obtenidos en el laboratorio de Psicofisiología de la Universidad de La Coruña. El trabajo abarca nuestra investigación sobre el efecto Simon y sobre el efecto accesorio, aunque no es una revisión del corpus teórico. La estrategia de investigación seguida en estos experimentos se basa en la utilización de potenciales motores lateralizados que se registran sobre cuero cabelludo. Estas medidas permiten observar cómo y cuándo se seleccionan las respuestas, proporcionando una valiosísima herramienta para estudiar la interferencia de respuesta y para partir el tiempo de reacción en dos mitades. Nuestra investigación sobre el efecto Simon concluye que la interferencia durante la selección de respuesta es crucial en el efecto Simon, pero no está tan claro si este proceso debe considerarse automático y guiado por el estímulo, como defienden la mayoría de las teorías actuales. Los experimentos con el efecto accesorio indican que la facilitación se produce antes de que termine la selección de respuesta, lo que acaba con una larga controversia acerca del locus del efecto accesorio

Evaluación de la asignatura de Fisiología de Sistemas a través del Cuestionario de Incidencias Críticas

[Resumen] El Espacio Europeo de Educación Superior (EEES) es el marco de referencia actual sobre el que trabajan las diferentes universidades que pertenecen a la Unión Europea. Dentro de este escenario se pone a disposición del alumnado una metodología más participativa, centrada en el desarrollo de habilidades y conocimiento. En este contexto se vuelve necesario que los profesores realicemos una evaluación crítica sobre nuestra actual actividad docente. Para conseguirlo es necesario conocer la opinión de nuestros estudiantes. Por ello, al finalizar el segundo cuatrimestre del curso 2017-2018, dentro del Grado en Podología (Facultad de Enfermería y Podología) y para la asignatura de Fisiología de Sistemas, hemos llevado a cabo un estudio piloto empleando el Cuestionario de Incidencias Críticas (Bará y Valero, 2003). En el cuestionario, compuesto de dos preguntas abiertas, se solicita al estudiantado que describa la incidencia crítica más positiva y más negativa que ha ocurrido durante el transcurso de la materia. Una vez obtenidos y analizados los resultados por la responsable de la materia, se compartieron las respuestas con el alumnado con el objetivo de hacerles saber que sus comentarios se tienen en cuenta, así como para tomar medidas oportunas de cara a resolver las incidencias más negativas. Como conclusión podemos decir que la aplicación del Cuestionario de Incidencias Críticas ha servido para conocer la opinión que nuestros estudiantes tienen sobre la materia, así como para detectar los puntos de mejora que se deben aplicar a la misma, lo que sin duda influirá en la calidad de nuestra docenci

Procesamiento visual temprano durante la rivalidad binocular

[Resumen] La tesis presentada se centro en estudiar los correlatos neurales de la conciencia visual empleando para ello tecnicas no invasivas electricas (potenciales evocados visuales, VEPs) y opticas durante la rivalidad binocular. En los experimentos de rivalidad binocular dos imágenes diferentes se presentan a cada ojo, causando dos interpretaciones perceptuales alternativas. Debido a que los cambios en la percepcion ocurren a pesar de que el estimulo visual es constante, el paradigma de rivalidad binocular ofrece una excelente oportunidad para estudiar los correlatos neurales de la conciencia visual. Los resultados con los VEPs revelaron un potencial, que se extiende desde los 100 hasta los 300 ms, relacionado con el estado de rivalidad. A este potencial se denomino RRP (Rivaly-Related Potencial, RRP). El temprano comienzo del RRP, distribucion y polaridad sugirio que este potencial podria originarse en el cortex visual primario o V1. El origen del RRP se investigo empleando una tecnica optica conocida con el nombre de EROS (Event-Related Optical Signal). En esta tecnica se injecta luz cerca del infrarrojo (NIR) en el craneo y se miden los cambios en la dispersion de la luz producidos por la estimulacion sensorial. La ventaja de esta tecnica optica es que posee una mayor resolucion espacial que la señal de EEG(electroencefalografia). Con estimulos foveales se encontro que la actividad en V1 no varia con el estado perceptual del sujeto