A new algorithm for electroencephalogram functional brain mapping based on an auditory-comprehension process

The main objective of this thesis is to gain insight on the dynamics of the human brain through electroencephalography (EEG) analysis, with emphasis placed on the characterization of the effects of an Auditory/Comprehension task. A thorough examination of the EEG recordings was accomplished through the use of the most common brain waves (Alpha, Beta, Delta, and Theta). Conceivably, as the EEG recordings based on these tasks become better understood, their use as a helpful tool in mapping the different functions of the brain will become more effective. The EEG data was collected from 15 patients at Miami Children\u27s Hospital using the ESI-256 system. A final evaluation of spectral arrays is performed based on comprehensive color topographic maps of the various induced brain activities. This representation allows us to bring out how different patients react under different circumstances, and to detect consequently neurological disorders such as the Attention Deficit Disorder (ADD)

Adaptive eye-gaze tracking using neural-network-based user profiles to assist people with motor disability

This study developed an adaptive real-time humancomputer interface (HCI) that serves as an assistive technology tool for people with severe motor disability. The proposed HCI design uses eye gaze as the primary computer input device. Controlling the mouse cursor with raw eye coordinates results in sporadic motion of the pointer because of the saccadic nature of the eye. Even though eye movements are subtle and completely imperceptible under normal circumstances, they considerably affect the accuracy of an eye-gaze-based HCI. The proposed HCI system is novel because it adapts to each specific user’s different and potentially changing jitter characteristics through the configuration and training of an artificial neural network (ANN) that is structured to minimize the mouse jitter. This task is based on feeding the ANN a user’s initially recorded eye-gaze behavior through a short training session. The ANN finds the relationship between the gaze coordinates and the mouse cursor position based on the multilayer perceptron model. An embedded graphical interface is used during the training session to generate user profiles that make up these unique ANN configurations. The results with 12 subjects in test 1, which involved following a moving target, showed an average jitter reduction of 35%; the results with 9 subjects in test 2, which involved following the contour of a square object, showed an average jitter reduction of 53%. For both results, the outcomes led to trajectories that were significantly smoother and apt at reaching fixed or moving targets with relative ease and within a 5% error margin or deviation from desired trajectories. The positive effects of such jitter reduction are presented graphically for visual appreciation

Exploring chemical kinetics at home in times of pandemic: Following the bleaching of food dye allura red using a smartphone

In this communication, a remote experimental activity in chemical kinetics is described, taking into account the quantification based on the optical sensor of a smartphone. The objective pursued herein is to equip students with the appropriate tools and strategies required to empirically determine the parameters of the rate law including reaction orders, rate constant (k), frequency factor (A), and activation energy (Ea). Typical results of the proposed protocol are shown and discussed in the framework of the bleaching reaction of food dye allura red (RD40) and hypochlorite, as a representative example. A graphical approach of the concentration vs time data measured under the experimental condition where [RD40] ≪ [ClO−] (isolation method) suggests a first-order kinetics with respect to the dye. In addition, the analysis of the pseudo-first-order constant (kobs) shows a firstorder relationship with respect to ClO−. In addition, using the two-point form of the Arrhenius equation, values of 3.22 × 107 s/M and 44.55 kJ/mol were obtained for A and Ea, respectively. Interestingly, all the kinetic parameters (reaction orders, k, A, and Ea) are on the same order of magnitude as those previously reported in the literature and acquired with more sophisticated and accurate equipment. This experience provides evidence that it is possible to proceed with remote experimental activities to deepen the collection and analysis of kinetic data during a pandemic.Fil: Madriz Ruiz, Lorean Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Cabrerizo, Franco Martín. Universidad Nacional de San Martin. Instituto Tecnologico de Chascomus. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - la Plata. Instituto Tecnologico de Chascomus.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vargas Balda, Ronald Eduardo. Universidad Nacional de San Martin. Instituto Tecnologico de Chascomus. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - la Plata. Instituto Tecnologico de Chascomus.; Argentin

Significance of Normalization on Anatomical MRI Measures in Predicting Alzheimer’s Disease

This study establishes a new approach for combining neuroimaging and neuropsychological measures for an optimal decisional space to classify subjects with Alzheimer’s disease (AD). This approach relies on a multivariate feature selection method with different MRI normalization techniques. Subcortical volume, cortical thickness, and surface area measures are obtained using MRIs from 189 participants (129 normal controls and 60 AD patients). Statistically significant variables were selected for each combination model to construct a multidimensional space for classification. Different normalization approaches were explored to gauge the effect on classification performance using a support vector machine classifier. Results indicate that theMini-mental state examination (MMSE) measure is most discriminative among single-measure models, while subcortical volume combined with MMSE is the most effective multivariate model for AD classification. The study demonstrates that subcortical volumes need not be normalized, whereas cortical thickness should be normalized either by intracranial volume ormean thickness, and surface area is a weak indicator of AD with and without normalization. On the significant brain regions, a nearly perfect symmetry is observed for subcortical volumes and cortical thickness, and a significant reduction in thickness is particularly seen in the temporal lobe, which is associated with brain deficits characterizing AD

Exploring Chemical Kinetics at Home in Times of Pandemic: Following the Bleaching of Food Dye Allura Red Using a Smartphone

In this communication, a remote experimental activity in chemical kinetics is described, taking into account the quantification based on the optical sensor of a smartphone. The objective pursued herein is to equip students with the appropriate tools and strategies required to empirically determine the parameters of the rate law including reaction orders, rate constant (k), frequency factor (A), and activation energy (Eₐ). Typical results of the proposed protocol are shown and discussed in the framework of the bleaching reaction of food dye allura red (RD40) and hypochlorite, as a representative example. A graphical approach of the concentration vs time data measured under the experimental condition where [RD40] ≪ [ClO⁻] (isolation method) suggests a first-order kinetics with respect to the dye. In addition, the analysis of the pseudo-first-order constant (kobs) shows a first-order relationship with respect to ClO⁻. In addition, using the two-point form of the Arrhenius equation, values of 3.22 × 10⁷ s/M and 44.55 kJ/mol were obtained for A and Eₐ, respectively. Interestingly, all the kinetic parameters (reaction orders, k, A, and Eₐ) are on the same order of magnitude as those previously reported in the literature and acquired with more sophisticated and accurate equipment. This experience provides evidence that it is possible to proceed with remote experimental activities to deepen the collection and analysis of kinetic data during a pandemic.Facultad de Ciencias ExactasInstituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Mejorando la seguridad del paciente: los medicamentos en la bandeja de anestesia.

Medication errors in anesthesia remain a serious cause of iatrogenic damage. We present a study in which the potential safety impact of the use of a tray with color codes for the preparation and storage of anesthetic drugs is evaluated.Los errores de medicación en anestesia, siguen siendo una causa grave de daño iatrogénico. Presentamos un estudio en el que se evalúa el potencial impacto de seguridad del uso de una bandeja con códigos de colores para la preparación y el almacenamiento de medicamentos anestésicos

A practical guideline for intracranial volume estimation in patients with Alzheimer’s disease

Background Intracranial volume (ICV) is an important normalization measure used in morphometric analyses to correct for head size in studies of Alzheimer Disease (AD). Inaccurate ICV estimation could introduce bias in the outcome. The current study provides a decision aid in defining protocols for ICV estimation in patients with Alzheimer disease in terms of sampling frequencies that can be optimally used on the volumetric MRI data, and the type of software most suitable for use in estimating the ICV measure. Methods Two groups of 22 subjects are considered, including adult controls (AC) and patients with Alzheimer Disease (AD). Reference measurements were calculated for each subject by manually tracing intracranial cavity by the means of visual inspection. The reliability of reference measurements were assured through intra- and inter- variation analyses. Three publicly well-known software packages (Freesurfer, FSL, and SPM) were examined in their ability to automatically estimate ICV across the groups. Results Analysis of the results supported the significant effect of estimation method, gender, cognitive condition of the subject and the interaction among method and cognitive condition factors in the measured ICV. Results on sub-sampling studies with a 95% confidence showed that in order to keep the accuracy of the interleaved slice sampling protocol above 99%, the sampling period cannot exceed 20 millimeters for AC and 15 millimeters for AD. Freesurfer showed promising estimates for both adult groups. However SPM showed more consistency in its ICV estimation over the different phases of the study. Conclusions This study emphasized the importance in selecting the appropriate protocol, the choice of the sampling period in the manual estimation of ICV and selection of suitable software for the automated estimation of ICV. The current study serves as an initial framework for establishing an appropriate protocol in both manual and automatic ICV estimations with different subject populations

A probabilistic approach for pediatric epilepsy diagnosis using brain functional connectivity networks

Background The lives of half a million children in the United States are severely affected due to the alterations in their functional and mental abilities which epilepsy causes. This study aims to introduce a novel decision support system for the diagnosis of pediatric epilepsy based on scalp EEG data in a clinical environment. Methods A new time varying approach for constructing functional connectivity networks (FCNs) of 18 subjects (7 subjects from pediatric control (PC) group and 11 subjects from pediatric epilepsy (PE) group) is implemented by moving a window with overlap to split the EEG signals into a total of 445 multi-channel EEG segments (91 for PC and 354 for PE) and finding the hypothetical functional connectivity strengths among EEG channels. FCNs are then mapped into the form of undirected graphs and subjected to extraction of graph theory based features. An unsupervised labeling technique based on Gaussian mixtures model (GMM) is then used to delineate the pediatric epilepsy group from the control group. Results The study results show the existence of a statistically significant difference (p \u3c 0.0001) between the mean FCNs of PC and PE groups. The system was able to diagnose pediatric epilepsy subjects with the accuracy of 88.8% with 81.8% sensitivity and 100% specificity purely based on exploration of associations among brain cortical regions and without a priori knowledge of diagnosis. Conclusions The current study created the potential of diagnosing epilepsy without need for long EEG recording session and time-consuming visual inspection as conventionally employed

Modelos de gestión en nutrición clínica. Puntos débiles y puntos fuertes

En el VIº Foro de Debate Abbott-SENPE se establece una discusión multidisciplinar y multiprofesional para buscar el o los modelos de gestión clínica que consideramos más adecuados para la Unidades de Nutrición Clínica y Dietética (UNCyD) en España. Se valoran los puntos débiles y fuertes así como las oportunidades de los actuales sistemas y se concluye en la observación de una cierta disparidad vinculada no solo a las comunidades autónomas sino también a los diferentes tipos de hospital. Se propone, desde SENPE, la creación de un grupo de trabajo que ayude a la normalización de los modelos y a potenciar la cultura del Cuadro de Mandos Integral y de Gestión del Cambio.At the 6th Abbott-SENPE Debate Forum a multidisciplinary and multiprofessional discussion was established in order to seek for the model or the models of clinical management most appropriate for Clinical Nutrition and Dietetics Units (CNAD) in Spain. The weaknesses and strengths as well as opportunities for the current systems were assessed concluding that a certain degree of disparity was observed not only due to regional differences but also to different hospital types. It was proposed, from SENPE, the creation of a working group helping to standardize the models and promote the culture of Integral Control and Change Management

Photoelectrochemistry in nanostructured systems: a discussion from their natural limitations

Luego de reconocer que la respuesta fotoelectroquímica depende de la yuxtaposición de fenómenos de transferencia y de recombinación de las cargas fotogeneradas, y que dichos procesos representan límites naturales al comportamiento experimental, se discuten algunos aspectos fisicoquímicos que determinan el desempeño de una interfase semiconductor | electrolito, considerando específicamente la situación de un fotoánodo nanoestructurado. Setomó como caso de estudio la relación entre la respuesta experimental de transferencia electrónica y la recombinación en nanotubos de TiO2, presentando estos una modificación en la relación de fases anatasa y rutilo. Mediante el análisis de la respuesta potenciodinámica a elevados sobrepotenciales en relación a la teoría de Gärtner, además de la cuantificación del tiempo de vida de portadores debido al decaimiento fotoluminiscente a circuito abierto, resultó posible ilustrar la relación cualitativa entre la cinética de transferencia de carga y la desactivación radiativa, procesos que, siendo opuestos, determinan la respuesta fotoelectroquímica de estos fotoánodos nanoestructurados.ABSTRACTThe physicochemical aspects behind the performance of a semiconductor electrolyte interphase are discussed, addressing the fact that the photoelectrochemical response depends on the juxtaposition of two fundamental phenomena: charge-carriers transfer and recombination. Such phenomena define the natural limits of the experimental behavior. Considering TiO2 nanotubes as a special case of study to illustrate the photoelectrochemical behavior of nanostructured electrodes, the analysis of the potentiodynamic response at high overpotentials in relation to Gärtner´s theory shows how the incorporation of a different phase (rutile into anatase) can modulate the experimental response. The quantification of the lifetime of carriers with to photoluminescent decays at open circuit illustrates how the relationship between the kinetics of charge transfer and recombination determines the natural limitations of nanostructured photoanodes performance.The physicochemical aspects behind the performance of a semiconductor | electrolyte interphase are discussed, addressing the fact that the photoelectrochemical response depends on the juxtaposition of two fundamental phenomena: charge-carriers transfer and recombination. Such phenomena define the natural limits of the experimental behavior. Considering TiO2 nanotubes as a special case of study to illustrate the photoelectrochemical behavior of nanostructured electrodes, the analysis of the potentiodynamic response at high overpotentials in relation to Gärtner's theory shows how the incorporation of a different phase (rutile into anatase) can modulate the experimental response. The quantification of the lifetime of carriers with to photoluminescent decays at open circuit illustrates how the relationship between the kinetics of charge transfer and recombination determines the natural limitations of nanostructured photoanodes performance.Fil: Leon, Dalia. Universidad Simon Bolivar.; VenezuelaFil: Torres, Daniel. Universidad Simon Bolivar.; VenezuelaFil: Maimone, Alberto. Universidad Simon Bolivar.; VenezuelaFil: Cabrerizo, Franco Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Madriz Ruiz, Lorean Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Vargas Balda, Ronald Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentin