Latent inhibition as a Model of Schizophrenia: from Learning to Psychopathology

In schizophrenia, attentional processes may be altered and become the basis of another symptomatology such as delirium and hallucinations. One of the experimental approaches to the study of attentional processes employs the phenomenon of latent inhibition. Behaviourally, latent inhibition is expressed as a delay or difficulty in learning the relationship between stimuli due to prior experience of the subject with one of the inconsequential stimuli. This learning phenomenon fulfils an adaptive function that enables the organism to release attention from irrelevant stimuli. Schizophrenics do not show this latent inhibition effect due to attentional alterations, that is, they have selective attention difficulties. Clinical data coincide with results obtained from both animals and normal subjects and with data from psychopharmacological studies. Most of the studies show that the dopaminergic system plays an important role in latent inhibition and therefore would support the dopaminergic hypothesis of schizophrenia. Furthermore, latent inhibition is used as a model to evaluate the mechanisms of antipsychotic drug action, as well as for the study of the aetiology of schizophrenia. Finally, latent inhibition opens a line of research in cognitive inhibition processes in schizotypy and the possibility of studying other psychopathological disorders. The model proposed is based on experimental, neurochemical and clinical premises that make it a promising topic of future for research

Broad-band and Hα surface photometry of the central regions of nearby active galaxies - I. Observations

This is an electronic version of an article published in Monthly Notices of the Royal Astronomical Society. Sánchez-Portal, M., Díaz, A.I., Terlevich, R., Terlevich, E., Álvarez Álvarez, M. and I. Aretxaga. Broad-band and Hα surface photometry of the central regions of nearby active galaxies - I. Observations. Monthly Notices of the Royal Astronomical Society 312 (2000): 2-3

Protective actions of α-tocopherol on cell membrane lipids of paraquat-stressed human astrocytes using microarray technology, MALDI-MS and lipidomic analysis

Producción CientíficaCellular senescence is one of the main contributors to some neurodegenerative disorders. The early detection of senescent cells or their related effects is a key aspect in treating disease progression. In this functional deterioration, oxidative stress and lipid peroxidation play an important role. Endogenous antioxidant compounds, such as α-tocopherol (vitamin E), can mitigate these undesirable effects, particularly lipid peroxidation, by blocking the reaction between free radicals and unsaturated fatty acid. While the antioxidant actions of α-tocopherol have been studied in various systems, monitoring the specific effects on cell membrane lipids at scales compatible with large screenings has not yet been accomplished. Understanding the changes responsible for this protection against one of the consequences of senescence is therefore necessary. Thus, the goal of this study was to determinate the changes in the lipid environment of a Paraquat-treated human astrocytic cell line, as a cellular oxidative stress model, and the specific actions of the antioxidant, α-tocopherol, using cell membrane microarray technology, MALDI-MS and lipidomic analysis. The stress induced by Paraquat exposure significantly decreased cell viability and triggered membrane lipid changes, such as an increase in certain species of ceramides that are lipid mediators of apoptotic pathways. The pre-treatment of cells with α-tocopherol mitigated these effects, enhancing cell viability and modulating the lipid profile in Paraquat-treated astrocytes. These results demonstrate the lipid modulation effects of α-tocopherol against Paraquat-promoted oxidative stress and validate a novel analytical high-throughput method combining cell cultures, microarray technology, MALDI-MS and multivariate analysis to study antioxidant compounds against cellular senescence.Ministerio de Economía y Competitividad - (grants DIN2019-010902 y PTQ 17-09409)Ministerio de Ciencia, Innovación y Universidades/Agencia Estatal de Investigación (AEI)/10.13039/501100011033 - (grant PID2019-110911RB-I00

Precios óptimos en el transporte interurbano por carretera

La publicación del Libro Blanco [European Transport Policy for 2010 (2001)] reconoce la necesidad de fijar un precio eficiente para cualquier infraestructura de transporte, esto es, fijar un precio que iguale el coste marginal social, lo que conlleva establecer una estructura variable de precios, que dependa del tipo de vehículo y de vía, así como del momento temporal en que se analiza el tráfico. Nuestro trabajo tiene como objetivo principal la identificación y estimación de los principales componentes que integrarían un precio óptimo para el transporte interurbano por carretera en España. Utilizando datos para el año 2000 se estima dicha estructura de precios óptimos diferenciando por tipo de vehículo, y se comparan con los precios que se derivan del actual sistema impositivo sobre la carreteraprecios, transporte interurbano, externalidades, coste marginal social, congestión

An Asynchronous P300-Based Brain-Computer Interface Web Browser for Severely Disabled People

This paper presents an electroencephalo- graphic (EEG) P300-based brain–computer interface (BCI) Internet browser. The system uses the “odd-ball” row-col paradigm for generating the P300 evoked potentials on the scalp of the user, which are immediately processed and translated into web browser commands. There were previous approaches for controlling a BCI web browser. However, to the best of our knowledge, none of them was focused on an assistive context, failing to test their applications with a suitable number of end users. In addition, all of them were synchronous applications, where it was necessary to introduce a “read-mode” command in order to avoid a continuous command selection. Thus, the aim of this study is twofold: 1) to test our web browser with a population of multiple sclerosis (MS) patients in order to assess the usefulness of our proposal to meet their daily communication needs; and 2) to overcome the aforementioned limitation by adding a threshold that discerns between control and non-control states, allowing the user to calmly read the web page without undesirable selections. The browser was tested with sixteen MS patients and five healthy volunteers. Both quantitative and qualitative metrics were obtained. MS participants reached an average accuracy of 84.14%, whereas 95.75% was achieved by control subjects. Results show that MS patients can successfully control the BCI web browser, improving their personal autonom

Improving the accessibility at home: implementation of a domotic application using a p300-based brain computer interface system

The aim of this study was to develop a Brain Computer Interface (BCI) application to control domotic devices usually present at home. Previous studies have shown that people with severe disabilities, both physical and cognitive ones, do not achieve high accuracy results using motor imagery-based BCIs. To overcome this limitation, we propose the implementation of a BCI application using P300 evoked potentials, because neither extensive training nor extremely high concentration level are required for this kind of BCIs. The implemented BCI application allows to control several devices as TV, DVD player, mini Hi-Fi system, multimedia hard drive, telephone, heater, fan and lights. Our aim is that potential users, i.e. people with severe disabilities, are able to achieve high accuracy. Therefore, this domotic BCI application is useful to increase their personal autonomy and independence, improving their quality of life.Peer Reviewe

Automated Analysis of Nocturnal Oximetry as Screening Tool for Childhood Obstructive Sleep Apnea-Hypopnea Syndrome

Producción CientíficaChildhood obstructive sleep apnea-hypopnea syndrome (OSAHS) is a highly prevalent condition that negatively affects health, performance and quality of life of infants and young children. Early detection and treatment improves neuropsychological and cognitive deficits linked with the disease. The aim of this study was to assess the performance of automated analysis of blood oxygen saturation (SpO2) recordings as a screening tool for OSAHS. As an initial step, statistical, spectral and nonlinear features were estimated to compose an initial feature set. Then, fast correlation-based filter (FCBF) was applied to search for the optimum subset. Finally, the discrimination power (OSAHS negative vs. OSAHS positive) of three pattern recognition algorithms was assessed: linear discriminant analysis (LDA), quadratic discriminant analysis (QDA) and logistic regression (LR). Three clinical cutoff points commonly used in the literature for positive diagnosis of the disease were applied: apnea-hypopnea index (AHI) of 1, 3 and 5 events per hour (e/h). Our methodology reached 88.6% accuracy (71.4% sensitivity and 100.0% specificity, 100.0% positive predictive value, and 84.0% negative predictive value) in an independent test set using QDA for a clinical cut-off point of 5 e/h. These results suggest that SpO2 nocturnal recordings may be used to develop a reliable and efficient screening tool for childhood OSAHSJunta de Castilla y León (project VA059U13

Positive airway pressure and electrical stimulation methods for obstructive sleep apnea treatment: a patent review (2005-2014)

Producción CientíficaIntroduction. Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a major health problem with significant negative effects on the health and quality of life. Continuous positive airway pressure (CPAP) is currently the primary treatment option and it is considered the most effective therapy for OSAHS. Nevertheless, comfort issues due to improper fit to patient’s changing needs and breathing gas leakage limit the patient’s adherence to treatment. Areas covered. The present patent review describes recent innovations in the treatment of OSAHS related to optimization of the positive pressure delivered to the patient, methods and systems for continuous self-adjusting pressure during inspiration and expiration phases, and techniques for electrical stimulation of nerves and muscles responsible for the airway patency. Expert opinion. In the last years, CPAP-related inventions have mainly focused on obtaining an optimal self-adjusting pressure according to patient’s needs. Despite intensive research carried out, treatment compliance is still a major issue. Hypoglossal electrical nerve stimulation could be an effective secondary treatment option when CPAP primary therapy fails. Several patents have been granted focused on selective stimulation techniques and parameter optimization of the stimulating pulse waveform. Nevertheless, there remain important issues to address, like effectiveness and adverse events due to improper stimulation.Ministerio de Economía y Competitividad (TEC2011-22987)Junta de Castilla y León (VA059U13

Utility of AdaBoost to Detect Sleep Apnea-Hypopnea Syndrome From Single-Channel Airflow

Producción CientíficaThe purpose of this study is to evaluate the usefulness of the boosting algorithm AdaBoost (AB) in the context of the sleep apnea-hypopnea syndrome (SAHS) diagnosis. Methods: We characterize SAHS in single-channel airflow (AF) signals from 317 subjects by the extraction of spectral and non-linear features. Relevancy and redundancy analyses are conducted through the fast correlation-based filter (FCBF) to derive the optimum set of features among them. These are used to feed classifiers based on linear discriminant analysis (LDA) and classification and regression trees (CART). LDA and CART models are sequentially obtained through AB, which combines their performances to reach higher diagnostic ability than each of them separately. Results: Our AB-LDA and AB-CART approaches showed high diagnostic performance when determining SAHS and its severity. The assessment of different apnea-hypopnea index cutoffs using an independent test set derived into high accuracy: 86.5% (5 events/h), 86.5% (10 events/h), 81.0% (15 events/h), and 83.3% (30 events/h). These results widely outperformed those from logistic regression and a conventional event-detection algorithm applied to the same database. Conclusion: Our results suggest that AB applied to data from single-channel AF can be useful to determine SAHS and its severity. Significance: SAHS detection might be simplified through the only use of single-channel AF data.Ministerio de Economía y Competitividad (project TEC2011-22987)Junta de Castilla y León (project VA059U13

Proyecto de inversión de pulidora digital para empresa dedicada a la transformación de lentes ópticos del municipio de San Salvador.

Uno de los sectores que en la actualidad proporciona muchas oportunidades de desarrollo a la economía nacional son los laboratorios ópticos, y que a su vez al ser desarrollado de una manera eficiente por las empresas que se dedican a este servicio aumentan sus posibilidades de negocios y ofrecer productos como lentes oftalmológicos, lentes de contacto, monturas y gafas de sol entre otros. A la vez que se generan beneficios económicos se colabora con el bienestar en la salud visual de la población salvadoreña del cual puede observarse que pueden suplirse necesidades básicas oftalmológicas a través de la transformación de lentes ópticos y mejorar la calidad de vida de las personas. Las empresas dedicadas a la transformación de lentes ópticos a través de la propuesta del proyecto de inversión para adquisición de la maquina pulidora, pretende mejorar los procesos productivos y aumentar la rentabilidad de la entidad. Este panorama vuelve necesario llevar a cabo un proyecto de inversión que ayude a estas empresas adoptar un nuevo proceso para la transformación de lentes ópticos, y así aprovechar los beneficios económicos que se espera obtener. El objetivo de esta investigación es la elaboración de un proyecto de inversión para la adquisición de pulidora digital para empresas dedicadas a la transformación de lentes ópticos, en la cual se muestra un panorama sobre los diversos aspectos que lo integran y como los ayudaría a incrementar sus utilidades. ii De acuerdo a las fuentes de financiamiento investigadas y propuestas a la entidad, la empresa solicito que la propuesta de proyecto de inversión de adquisición de pulidora digital sea a través de préstamo bancario con una institución autorizada por la superintendencia del sistema financiero Para alcanzar el logro de este objetivo se detalló la metodología de la investigación donde se explica el enfoque cualitativo y método hipotético-inductivo que parte de lo particular a lo general, tipo de investigación se aplica es el analítico descriptivo a desarrollar donde se identifica el problema sus causas y efectos, a través de la propuesta de adquisición maquina pulidora de lentes ópticos con la proyección de Estados Financieros y el análisis de los indicadores de financieros que se evaluaron y de las respuestas obtenidas a través de la recolección y el análisis de información. Durante la investigación se utilizó la encuesta como recolección de información, al obtener las respuestas de la guía de preguntas dirigidas al gerente financiero, se elaboró un diagnóstico del cual se desarrolla las conclusiones y recomendaciones de la investigación. En base a los resultados se identifica la necesidad de elaborar esta propuesta de proyecto de inversión de la adquisición de maquinaria pulidora para la elaboración de lentes ópticos