53 research outputs found

    Co-diseño de un sistema de detección de señales de tráfico con SDSoC

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    La visión artificial es una disciplina científica muy estudiada hoy en día y uno de los campos más prometedores para el futuro. Una de las áreas donde cada vez está más introducida es en el ámbito automovilístico, siendo uno de los pilares fundamentales del coche autónomo. En este trabajo se pretende aplicar la visión artificial para crear un detector de señales de tráfico. Se hará un co-diseño HW/SW con la idea de combinar todos los beneficios de un SO que corre en un microprocesador con los de la capacidad de procesamiento en paralelo de una FPGA. Esto se desarrollará con la herramienta SDSoC de Xilinx y se implementará sobre una plataforma Zedboard. Se analizará también el rendimiento obtenido en velocidad al emplear sistemas heterogéneos en este tipo de aplicaciones y la eficiencia de las técnicas de visión artificial implementadas.Computer vision is a scientific discipline that is very studied nowadays and one of the most promising sectors for the future. One of the areas where it is increasingly introduced is in the automobile field, being one of the fundamental parts of the autonomous car. In this dissertation, the intention is to apply computer visión to the creation of a road signs detector. We will do a HW/SW co-design with the idea of combining all the benefits of an OS running on a microprocessor with those of the parallel processing capacity of an FPGA. This will be developed with the Xilinx SDSoC tool and it will be implemented on a Zedboard platform. It will also analyze the performance obtained in speed using heterogeneous systems in this type of applications and the efficiency of the artificial vision techniques implemented.Universidad de Sevilla. Grado en Ingeniería de las Tecnologías de Telecomunicació

    Event-related potentials associated to N-back test performance in schizophrenia

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    Producción CientíficaMapping of Event-Related Potentials (ERP) associated with auditory and visual odd-ball paradigms has shown consistent differences between healthy controls and schizophrenia patients. It may be hypothesized that higher task attentional/cognitive demand will result in larger differences in these paradigms, which may help understanding the substrates of cognitive deficits in this syndrome. To this aim, we performed an EEG study comparing the effects of increasing the attentional/cognitive load of an auditory N-back task on the Event-Related Potential in 50 subjects with schizophrenia (11 first episodes) and 35 healthy controls. We considered a post-target window of 1000 ms to explore possible between groups differences in N100, P300, and Late Slow Wave (LSW), and compared these components between 0-back (‘lower attentional/cognitive load) and 1-back (‘higher attentional/cognitive load’) conditions. Our results showed that N100 and LSW amplitude increase from 0- to 1-back condition was significantly larger in healthy controls compared to schizophrenia patients. Furthermore, LSW amplitude difference between 0- and 1-back conditions positively correlated with performance in the behavioral cognitive assessment. Taken together, these results support that higher task attentional/cognitive load (0-back vs. 1-back condition) increase N100 amplitude differences and reveal new findings related to the LSW component in schizophrenia.Junta de Castilla y León (project VA057P17)Instituto de Salud Carlos III (project PI18/00178

    Diffusion tensor imaging in orthostatic tremor: a tract-based spatial statistics study.

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    Objective: The pathogenesis of orthostatic tremor (OT) is unknown. We investigated OT-related white matter changes and their correlations with scores from a neuropsychological testing battery. Methods: Diffusion tensor imaging measures were compared between 14 OT patients and 14 age- and educationmatched healthy controls, using whole-brain tract-based spatial statistics analysis. Correlations between altered diffusion metrics and cognitive performance in OT group were assessed. Results: In all cognitive domains (attention, executive function, visuospatial ability, verbal memory, visual memory, and language), OT patients’ cognitive performance was significantly worse than that of healthy controls. OT patients demonstrated altered diffusivity metrics not only in the posterior lobe of the cerebellum (left cerebellar lobule VI) and in its efferent cerebellar fibers (left superior cerebellar peduncle), but also in medial lemniscus bilaterally (pontine tegmentum), anterior limb of the internal capsule bilaterally, right posterior limb of the internal capsule, left anterior corona radiata, right insula, and the splenium of corpus callosum. No relationship was found between diffusion measures and disease duration in OT patients. Diffusion white matter changes, mainly those located in right anterior limb of the internal capsule, were correlated with poor performance on tests of executive function, visuospatial ability, verbal memory, and visual memory in OT patients. Interpretation: White matter changes were preferentially located in the cerebellum, its efferent pathways, as well as in the pontine tegmentum and key components of the frontal–thalamic–cerebellar circuit. Further work needs to be done to understand the evolution of these white matter changes and their functional consequences.post-print404 K

    Analysis of the functional EEG network in an Ecuadorian schizophrenia sample

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    Background and objectives Higher mental functions depend on global functional coordination of the brain. Our aim was to study the baseline condition and modulation of functional networks in a previously unevaluated clinical population, compare the results with a population from another country, and analyze their relationship with cognitive functioning. Methods We evaluated the functioning of brain networks by EEG in 24 patients with schizophrenia and 32 healthy Ecuadorian controls. EEG recordings were made at rest and while performing a P300 task. Small world (SW), Path Length (PL), clustering coefficient (CLC) and connective strength (CS) values were calculated in both conditions. The values obtained were compared between groups, with the results of Spanish patients, and the relationship between the connective parameters and the cognitive performance of the participants was analyzed. Results Higher PL, CLC and CS values were identified in patients diagnosed with schizophrenia compared to controls (in basal condition) and lower SW values in this same condition. Ecuadorian patients obtained higher values than Spanish patients in the PL and CLC parameters and lower values for the SW parameter, despite these differences, the pattern of alteration in both samples followed the same trend. Finally, the alteration of CS, SW, CLC and PL parameters at baseline was related to cognitive performance. Conclusion The connective alterations identified in Ecuadorian schizophrenic patients are consistent with those found in another sample with different genetic, environmental and cultural conditions. In addition, these alterations were associated with worse performance in different cognitive domains

    Cognitive and Neuropsychiatric Features of Orthostatic Tremor: A Case-Control Comparison.

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    Introduction Evidence suggests that the cerebellum could play a role in the pathophysiology of orthostatic tremor. The link between orthostatic tremor and the cerebellum is of interest, especially in light of the role the cerebellum plays in cognition, and it raises the possibility that orthostatic tremor patients could have cognitive deficits consistent with cerebellar dysfunction. Our aim was to examine whether orthostatic tremor patients had cognitive deficits and distinct personality profiles when compared with matched controls. Methods Sixteen consecutive orthostatic tremor patients (65.7 ± 13.3 years) and 32 healthy matched controls underwent a neuropsychological battery and the Personality Assessment Inventory. In linear regression models, the dependent variable was each one of the neuropsychological test scores or the Personality Assessment Inventory subscales and the independent variable was orthostatic tremor vs. control. Results Adjusted for age in years, sex, years of education, comorbidity index, current smoker, and depressive symptoms, diagnosis (orthostatic tremor vs. healthy control) was associated with poor performance on tests of executive function, visuospatial ability, verbal memory, visual memory, and language tests, and on a number of the Personality Assessment Inventory subscales (somatic concerns, anxiety related disorders, depression, and antisocial features). Older-onset OT (> 60 years) patients had poorer scores on cognitive and personality testing compared with their younger-onset OT counterparts. Conclusion Orthostatic tremor patients have deficits in specific aspects of neuropsychological functioning, particularly those thought to rely on the integrity of the prefrontal cortex, which suggests involvement of frontocerebellar circuits. Cognitive impairment and personality disturbances could be disease-associated nonmotor manifestations of orthostatic tremor.pre-print426 K

    Viabilidad de uso del polvo de vidrio como fundente en la elaboración de baldosas de gres porcelánico

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    This article presents the results of a research on the use of glass powder as substitute of feldspar for manufacturing stoneware tiles. Mixtures were prepared in which glass powder substituted feldspar in two different percentages (25 wt% and 50 wt%). Specimens of the obtained mixtures were molded, dried and sintered. Physical (apparent density, porousness, absorption, among others) and mechanical properties (flexion resistance) of standard sintered bodies (V0) were compared to the sintered bodies in which the melting material was substituted in the formulation by glass powder in percentages of 25% and 50% (V25 and V50). It was found that the glass powder addition in the formulations caused decrease in flexion resistance and increase in water absorption values. However, the melting action of glass powder reduced the sintering temperature in regards with the standard mixture in 150 °C for substitutions of 50% and 25%, respectively. By using Scanning Electron Microscopy (SEM) needles of primary mullite and secondary mullite (elongated needles) in a vitreous phase were identified.En este artículo se presentan los resultados de una investigación sobre el uso del polvo de vidrio como remplazo del feldespato en la fabricación de gres porcelánico. Se prepararon mezclas en donde el polvo de vidrio sustituyó al feldespato en dos volúmenes distintos (25% y 50%). Especímenes de las pastas obtenidas fueron moldeados, secados y cocidos. Las propiedades físicas (densidad aparente, porosidad, absorción, entre otras) y mecánicas (resistencia a flexión) de los especímenes cocidos estándar (V0) se compararon con las de especímenes cocidos en donde el material fundente fue sustituido en la formulación por polvo de vidrio en porcentajes de 25% y 50% (V25 y V50). Se encontró que la adición de polvo de vidrio en las formulaciones ocasionaba disminución en la resistencia a la flexión e incremento en los valores de absorción de agua. Sin embargo, la acción fundente del polvo de vidrio disminuyó la temperatura de sinterización respecto a la mezcla estándar en 150 °C para remplazos de 50% y 25%, respectivamente. Mediante MEB se evidenció en la microestructura de las piezas cocidas (V0, V25 y V50) la presencia de cristales de mullita primaria, adyacentes a cristales de mullita secundaria (agujas elongadas)

    In vivo neurometabolic profiling in orthostatic tremor

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    The pathogenesis of orthostatic tremor (OT) remains unclear, although some evidence points to dysfunction in the brainstem or cerebellum. We used single voxel proton magnetic resonance spectroscopy (1H-MRS) (3 T) to investigate whether neurochemical changes underlie abnormal cerebellar or cortical function in OT. Fourteen OT patients and 14 healthy controls underwent 1H-MRS studies with voxels placed in midparietal gray matter and cerebellum (vermis and central white matter). Spectral analysis was analyzed using the software package LCModel (version 6.3). The absolute metabolite concentrations and ratios of total N-acetylaspartate + N-acetylaspartyl glutamate (NAA), choline-containing compounds, myoinositol, and glutamate + glutamine to creatine were calculated. In midparietal gray matter spectra, we found a significant decrease in the absolute concentration of NAA in OT patients versus healthy controls (7.76 ± 0.25 vs 8.11 ± 0.45, P = 0.017). A similar decrease in NAA was seen in the cerebellar vermis (7.33 ± 0.61 vs 8.55 ± 1.54, P = 0.014) and cerebellar white matter (8.54 ± 0.79 vs 9.95 ± 1.57, P = 0.010). No differences in the other metabolites or their ratios were observed. Reductions in both cerebral cortical and cerebellar NAA suggest that there is neuronal damage or loss in OT, raising the intriguing question as to whether OT is a neurodegenerative disease. Along with clinical history and electrophysio0logical examination, 1H-MRS could serve as a useful diagnostic aid for OT

    Resting state functional MRI reveals abnormal network connectivity in orthostatic tremor.

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    Very little is known about the pathogenesis of orthostatic tremor (OT). We have observed that OT patientsmight have deficits in specific aspects of neuropsychological function, particularly those thought to rely on the integrity of the prefrontal cortex, which suggests a possible involvement of frontocerebellar circuits. We examined whether resting-state functional magnetic resonance imaging (fMRI) might provide further insights into the pathogenesis on OT. Resting-state fMRI data in 13 OT patients (11 women and 2 men) and 13 matched healthy controls were analyzed using independent component analysis, in combination with a “dual-regression” technique, to identify group differences in several resting-state networks (RSNs). All participants also underwent neuropsychological testing during the same session. Relative to healthy controls, OT patients showed increased connectivity in RSNs involved in cognitive processes (default mode network [DMN] and frontoparietal networks), and decreased connectivity in the cerebellumand sensorimotor networks.Changes in network integrity were associated not onlywith duration (DMN and medial visual network), but also with cognitive function. Moreover, in at least 2 networks (DMN and medial visual network), increased connectivity was associated with worse performance on different cognitive domains (attention, executive function, visuospatial ability, visual memory, and language). In this exploratory study, we observed selective impairments ofRSNs inOT patients. This and other future resting-state fMRI studiesmight provide a novelmethod to understand the pathophysiological mechanisms of motor and nonmotor features of OT.post-print571 K
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