451 research outputs found

    Abstract computation in schizophrenia detection through artificial neural network based systems

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    Schizophrenia stands for a long-lasting state of mental uncertainty that may bring to an end the relation among behavior, thought, and emotion; that is, it may lead to unreliable perception, not suitable actions and feelings, and a sense of mental fragmentation. Indeed, its diagnosis is done over a large period of time; continuos signs of the disturbance persist for at least 6 (six) months. Once detected, the psychiatrist diagnosis is made through the clinical interview and a series of psychic tests, addressed mainly to avoid the diagnosis of other mental states or diseases. Undeniably, the main problem with identifying schizophrenia is the difficulty to distinguish its symptoms from those associated to different untidiness or roles. Therefore, this work will focus on the development of a diagnostic support system, in terms of its knowledge representation and reasoning procedures, based on a blended of Logic Programming and Artificial Neural Networks approaches to computing, taking advantage of a novel approach to knowledge representation and reasoning, which aims to solve the problems associated in the handling (i.e., to stand for and reason) of defective information.This work is funded by National Funds through the FCT, Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) within projects PEstOE/EEI/UI0752/2014 and PEst-OE/QUI/UI0619/2012

    Improving the PCR protocol to amplify a repetitive DNA sequence

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    Although PCR-based techniques have become an essential tool in the field of molecular and genetic research, the amplification of repetitive DNA sequences is limited. This is due to the truncated nature of the amplified sequences, which are also prone to errors during DNA polymerase-based amplification. The complex structure of repetitive DNA can form hairpin loops, which promote dissociation of the polymerase from the template, impairing complete amplification, and leading to the formation of incomplete fragments that serve as megaprimers. These megaprimers anneal with other sequences, generating unexpected fragments in each PCR cycle. Our gene model, MaSp1, is 1037-bp long, with 68% GC content, and its amino acid sequence is characterized by poly-alanine-glycine motifs, which represent the repetitive codon consensus. We describe the amplification of the MaSp1 gene through minor changes in the PCR program. The results show that a denaturation temperature of 98°C is the key determinant in the amplification of the MaSp1 partial gene sequence

    Applications of infrared thermography in sports. A review

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    La termografía infrarroja (TI) registra el calor irradiado de un cuerpo, que es emitido en un rango del espectro electromagnético que la visión humana no es capaz de identificar. La respuesta térmica depende de una serie de ajustes fisiológicos específicos como la homeostasis corporal y salud del deportista, lo cual permite establecer interesantes aplicaciones en el deporte. El objetivo de este trabajo ha sido revisar la literatura en torno a las aplicaciones de la TI en el ámbito del deporte, y proponer las características óptimas del registro en relación al evaluado, las condiciones ambientales y la cámara utilizada. Concluimos que la principal contribución de la TI en el ámbito del deporte es ayudar a identificar signos de lesión antes de que la lesión se produzca, permitiéndonos actuar de manera preventiva durante el proceso de entrenamientoInfrared thermography (IRT) records the radiant heat of a body, which is emitted in the range of the electromagnetic spectrum that human vision is not able to identify. The thermal response depends on a number of specific physiological adjustments as body homeostasis and athlete’s health, which allow us to establishing interesting applications in sport. The aim of this study was to review the literature on IRT applications in sports, and to propose the optimal characteristics of the register in terms of the subject, the environmental conditions and the camera used. We conclude that the main contribution of IRT in the field of sport is to help identify signs of injury before it occurs, allowing us to act proactively along the training proces

    Supplements of carbohydrates long during exercise: Effects on the electrolytes and glucose

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    Objetivo: Identificar si la forma de presentación de los suplementos de carbohidratos (SC) influye en la respuesta de la concentración plasmática de electrólitos y glucosa durante un ejercicio de larga duración. Doce hombres realizaron cuatro pruebas de 90 min en cicloergometro (55-60%VO2máx), seguidas por 6 km a máxima velocidad, consumiendo SC en diferentes presentaciones (líquido, gel o sólido) y un día únicamente consumían agua. Se analizaron las concentraciones de sodio, potasio y glucosa en sangre antes del ejercicio, cada 30 minutos de prueba, y tras los 6 km. No hubo diferencia significativa en la respuesta de los electrolitos durante todo estudio. Hubo diferencias significativas (p<0,05) en la glucosa cuando se consumieron SC independientemente de su presentación frente al consumo exclusivo de agua. Se concluye que la forma de presentación de los SC no influye en la concentración de glucosa en sangre durante el ejercicio de larga duraciónObjective: To identify if the format of carbohydrate supplements (CS) influence the response of the plasmatic concentration of electrolytes and glucose during long duration exercise. Twelve men performed four tests of 90 min on a cycle ergometer (55-60% VO2max), followed by 6 km at maximum speed, consuming CS in different forms (liquid, gel or solid) and one day just consuming water. It was analyzed the concentrations of sodium, potassium and blood glucose before exercise, every 30 minutes of test, and after 6 km. There was no significant difference in the response of electrolytes during the study. However, the glucose showed significant differences (p <0.05) when it was consumed CS regardless of their form, whenever just water was consumed. In this way is possible to conclude, that the format of the SC does not affect the blood glucose concentration during long duration exercis

    Flexible n-i-p thin film silicon solar cells on polyimide foils with textured ZnO:Ga back reflector

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    In thin film silicon solar cells on opaque substrates in n-i-p deposition sequence where the textured transparent conductive oxide (TCO) layer serves as a back reflector, one can independently optimize the morphology of the TCO layer without compromise on transparency and conductivity of this layer and further adjust the electro-optical properties of the back contact by using additional layers on top of the textured TCO. In the present work, we use this strategy to obtain textured back reflectors for solar cells in n-i-p deposition sequence on non-transparent flexible plastic foils. Gallium doped ZnO (ZnO:Ga) films were deposited on polyimide substrates by DC magnetron sputtering at a temperature of 200 °C. A wet-chemical etching step was performed by dipping the ZnO:Ga covered foil into a diluted HCl solution. The textured ZnO:Ga is then coated with a highly reflective Ag/ZnO double layer. On this back reflector, we develop thin film silicon solar cells with a microcrystalline silicon absorber layer. The current density for the cell with the textured ZnO:Ga layer is ~ 23 mA/cm2, 4 mA/cm2 higher than the one without such layer, and a maximum efficiency of 7.5% is obtained for a 1 cm2 cell.Fundação para a Ciência e a Tecnologia (FCT

    Piezoresistive silicon thin film sensor array for biomedical applications

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    N-type hydrogenated nanocrystalline silicon thin film piezoresistors, with gauge factor −28, were deposited on rugged and flexible polyimide foils by Hot-wire chemical vapor deposition using a tantalum filament heated to 1750 °C. The piezoresistive response under cyclic quasi-static and dynamical (up to 100 Hz) load conditions is reported. Test structures, consisting of microresistors having lateral dimensions in the range from 50 to 100 μm and thickness of 120 nm were defined in an array by reactive ion etching. Metallic pads, forming ohmic contacts to the sensing elements, were defined by a lift-off process. A readout circuit for the array consisting in a mutiplexer on each row and column of the matrix is proposed. The digital data will be processed, interpreted and stored internally by an ultra low-power micro controller, also responsible for the communication of two-way wireless data, e.g. from inside to outside the human body.© 2011 Elsevier B.V. All rights reservedFundação para a Ciência e a Tecnologia (FCT

    One session of fMRI-Neurofeedback training on motor imagery modulates whole-brain effective connectivity and dynamical complexity

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    In the past decade, several studies have shown that Neurofeedback (NFB) by functional magnetic resonance imaging can alter the functional coupling of targeted and non-targeted areas. However, the causal mechanisms underlying these changes remain uncertain. Here, we applied a whole-brain dynamical model to estimate Effective Connectivity (EC) profiles of resting-state data acquired before and immediately after a single-session NFB training for 17 participants who underwent motor imagery NFB training and 16 healthy controls who received sham feedback. Within-group and between-group classification analyses revealed that only for the NFB group it was possible to accurately discriminate between the 2 resting-state sessions. NFB training-related signatures were reflected in a support network of direct connections between areas involved in reward processing and implicit learning, together with regions belonging to the somatomotor, control, attention, and default mode networks, identified through a recursive-feature elimination procedure. By applying a data-driven approach to explore NFB-induced changes in spatiotemporal dynamics, we demonstrated that these regions also showed decreased switching between different brain states (i.e. metastability) only following real NFB training. Overall, our findings contribute to the understanding of NFB impact on the whole brain's structure and function by shedding light on the direct connections between brain areas affected by NFB training

    Deposition of silicon nitride thin films by hot-wire CVD at 100ºC and 250ºC

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    Silicon nitride thin films for use as passivation layers in solar cells and organic electronics or as gate dielectrics in thin-film transistors were deposited by the Hot-wire chemical vapor deposition technique at a high deposition rate (1-3 Ǻ/s) and at low substrate temperature. Films were deposited using NH3/SiH4 flow rate ratios between 1 and 70 and substrate temperatures of 100º C and 250ºC. For NH3/SiH4 ratios between 40 and 70, highly transparent (T ~ 90%), dense films (2.56 - 2.74 g/cm3) with good dielectric properties and refractive index between 1.93 and 2.08 were deposited on glass substrates. Etch rates in BHF of 2.7 Ǻ/s and 10 MV cm−1.Fundação para a Ciência e Tecnologia (FCT) - FCT/CNRS programa com o contracto no. 20798, bolsa de investigaçao e projecto PTDC-CTM-66558-200

    A simulation algorithm for optimization of mixture design applied to the assignment of weights in a goal programming problem

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    Ferreira, Ana Cristina, e outros (2023) - International conference on technology management and operations. - Lisboa : Universidade Lusíada Editora. - ISBN 978-898-640-273-0.Experimental design approaches are essential for improving products and processes, and their use is often decisive in achieving a successful target result. Thus, mixture design is a method for designing experiments which considers that the result does not depend on the total amount but on the proportions of the components. Mixture design techniques are often applied to problems in food, beverage, pharmaceutical health, and cement-based materials, among others, and one may also use them to help solve multi-objective problems when the weights of the objective function components can interfere with the optimization process. Therefore, given the relevance of studies on mixture planning and the increasing use of methods and techniques to consider uncertainty, the objective of this study is to propose an approach to deal with uncertainties in the coefficients of polynomial objective functions for the optimization of mixture design problem considering optimization via Monte Carlo Simulation. Computational tests were made using R software with instances from a literature study on a waste paper recycling logistics problem where the assignment of model weights is part of the process. Comparing the results to those obtained using the General Algebraic Modeling System language and CPLEX solver, they showed that considering uncertainty in the coefficients of objective function assisted in minimizing the difference between the obtained results, allowing for improvement in the representation of several scenarios. The developed approach also provided solution possibilities to help choose the best weights to optimize goal programming problems
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