Encoding cortical dynamics in sparse features.

Distributed cortical solutions of magnetoencephalography (MEG) and electroencephalography (EEG) exhibit complex spatial and temporal dynamics. The extraction of patterns of interest and dynamic features from these cortical signals has so far relied on the expertise of investigators. There is a definite need in both clinical and neuroscience research for a method that will extract critical features from high-dimensional neuroimaging data in an automatic fashion. We have previously demonstrated the use of optical flow techniques for evaluating the kinematic properties of motion field projected on non-flat manifolds like in a cortical surface. We have further extended this framework to automatically detect features in the optical flow vector field by using the modified and extended 2-Riemannian Helmholtz-Hodge decomposition (HHD). Here, we applied these mathematical models on simulation and MEG data recorded from a healthy individual during a somatosensory experiment and an epilepsy pediatric patient during sleep. We tested whether our technique can automatically extract salient dynamical features of cortical activity. Simulation results indicated that we can precisely reproduce the simulated cortical dynamics with HHD; encode them in sparse features and represent the propagation of brain activity between distinct cortical areas. Using HHD, we decoded the somatosensory N20 component into two HHD features and represented the dynamics of brain activity as a traveling source between two primary somatosensory regions. In the epilepsy patient, we displayed the propagation of the epileptic activity around the margins of a brain lesion. Our findings indicate that HHD measures computed from cortical dynamics can: (i) quantitatively access the cortical dynamics in both healthy and disease brain in terms of sparse features and dynamic brain activity propagation between distinct cortical areas, and (ii) facilitate a reproducible, automated analysis of experimental and clinical MEG/EEG source imaging data

Estudio comparativo sobre el logro de competencias educativas en la asignatura de estudios sociales en el segundo ciclo de educación básica y el abordaje didáctico pedagógico en el sistema integrado n° 13 del Municipio de Santa Ana, del Departamento de Santa Ana

A lo largo de la historia de la enseñanza de las Ciencias Sociales y en particular los Estudios Sociales, este último expresado en el currículo nacional, busca ofrecer en el alumnado una visión amplia de la sociedad donde vive, su origen y evolución histórica, el papel que juega en el marco de la geografía y en los diferentes sucesos del mundo. Por tanto, resulta importante hacer un estudio sobre el accionar didáctico, la metodología, los recursos que emplea y el desarrollo de los contenido

Somatosensory cortex functional connectivity abnormalities in autism show opposite trends, depending on direction and spatial scale

Functional connectivity is abnormal in autism, but the nature of these abnormalities remains elusive. Different studies, mostly using functional magnetic resonance imaging, have found increased, decreased, or even mixed pattern functional connectivity abnormalities in autism, but no unifying framework has emerged to date. We measured functional connectivity in individuals with autism and in controls using magnetoencephalography, which allowed us to resolve both the directionality (feedforward versus feedback) and spatial scale (local or long-range) of functional connectivity. Specifically, we measured the cortical response and functional connectivity during a passive 25-Hz vibrotactile stimulation in the somatosensory cortex of 20 typically developing individuals and 15 individuals with autism, all males and right-handed, aged 8-18, and the mu-rhythm during resting state in a subset of these participants (12 per group, same age range). Two major significant group differences emerged in the response to the vibrotactile stimulus. First, the 50-Hz phase locking component of the cortical response, generated locally in the primary (S1) and secondary (S2) somatosensory cortex, was reduced in the autism group (P < 0.003, corrected). Second, feedforward functional connectivity between S1 and S2 was increased in the autism group (P < 0.004, corrected). During resting state, there was no group difference in the mu-α rhythm. In contrast, the mu-β rhythm, which has been associated with feedback connectivity, was significantly reduced in the autism group (P < 0.04, corrected). Furthermore, the strength of the mu-β was correlated to the relative strength of 50 Hz component of the response to the vibrotactile stimulus (r = 0.78, P < 0.00005), indicating a shared aetiology for these seemingly unrelated abnormalities. These magnetoencephalography-derived measures were correlated with two different behavioural sensory processing scores (P < 0.01 and P < 0.02 for the autism group, P < 0.01 and P < 0.0001 for the typical group), with autism severity (P < 0.03), and with diagnosis (89% accuracy). A biophysically realistic computational model using data driven feedforward and feedback parameters replicated the magnetoencephalography data faithfully. The direct observation of both abnormally increased and abnormally decreased functional connectivity in autism occurring simultaneously in different functional connectivity streams, offers a potential unifying framework for the unexplained discrepancies in current findings. Given that cortical feedback, whether local or long-range, is intrinsically non-linear, while cortical feedforward is generally linear relative to the stimulus, the present results suggest decreased non-linearity alongside an increased veridical component of the cortical response in autism

Altered Onset Response Dynamics in Somatosensory Processing in Autism Spectrum Disorder.

Abnormalities in cortical connectivity and evoked responses have been extensively documented in autism spectrum disorder (ASD). However, specific signatures of these cortical abnormalities remain elusive, with data pointing toward abnormal patterns of both increased and reduced response amplitudes and functional connectivity. We have previously proposed, using magnetoencephalography (MEG) data, that apparent inconsistencies in prior studies could be reconciled if functional connectivity in ASD was reduced in the feedback (top-down) direction, but increased in the feedforward (bottom-up) direction. Here, we continue this line of investigation by assessing abnormalities restricted to the onset, feedforward inputs driven, component of the response to vibrotactile stimuli in somatosensory cortex in ASD. Using a novel method that measures the spatio-temporal divergence of cortical activation, we found that relative to typically developing participants, the ASD group was characterized by an increase in the initial onset component of the cortical response, and a faster spread of local activity. Given the early time window, the results could be interpreted as increased thalamocortical feedforward connectivity in ASD, and offer a plausible mechanism for the previously observed increased response variability in ASD, as well as for the commonly observed behaviorally measured tactile processing abnormalities associated with the disorder

Prevalencia de síndrome de anticuerpos antifosfolípidos en pacientes con preeclampsia severa de Enero 2019 a Diciembre 2020

La preeclampsia es morbilidad asociada al embarazo por la cual se presentan resultados adversos que incrementa la morbimortalidad materna y neonatal, uno de los factores de riesgo en pacientes que desarrollan esta afección es el síndrome de anticuerpos antifosfolípidos (SAAF), que engloba trastornos trombóticos y predispone a perdidas gestacionales y aumenta el porcentaje de desarrollar preeclampsia con características de gravedad. De 307 casos de preeclampsia severa de pacientes que consultaron o fueron referidas a Hospital 1ro de Mayo, al menos 27% padecían de alguna morbilidad médica y de estas el 8 % correspondían a SAAF. Lo anterior nos lleva a conocer la evolución clínica de la enfermedad en relación a SAAF como edad gestacional de presentación, otros factores de riesgo maternos y morbimortalidad neonatal asociadas. Investigamos 307 casos de cuadros de preeclampsia severa atendidos en el Hospital 1ro de Mayo entre 2019-2020, se identificaron antecedentes clínicos de relevancia, partos previos, complicaciones presentadas al momento del parto y se cruzaron datos obstétricos relacionados a la edad de presentación y morbimortalidad materna y neonatal para determinar la incidencia de SAAF y preeclampsia severa y lograr identificar edad gestacional de aparecimiento de la enfermedad así como los resultados adversos más frecuentes esperados. La Preeclampsia severa se presentó en su mayoría (82%) en pacientes cuya edad reproductiva no se relaciona directamente con el aparecimiento de preeclampsia severa, de estas solo el 2 % contaba con diagnóstico de SAAF al momento de la presentación, el 48.9% de las pacientes no lograron llegar a un parto de termino debido a finalización prematura por preeclampsia severa. La complicación más frecuente fue relacionadas a hemorragia posparto en 51%, las relacionadas a preeclampsia en un 25.5% como eclampsia (54.5%) y síndrome de HELLP 27.2% e insuficiencia renal aguada en un 18.1%. El resto 23.9 % con causas infecciosas como corioamnionitis, neumonía y sepsis. El 66.7 % de las pacientes con diagnóstico de síndrome antifosfolípidos no presente otra complicación asociada al parto, y el 33.3% presento muerte perinatal. En el Hospital 1ro de Mayo la tasa de mortalidad materna por preeclampsia severa asociada a SAAF es baja sin embargo la mortalidad neonatal si presenta una tasa de letalidad elevada cuando los dos cuadros clínicos se presentan juntos. Es más frecuente la prevalencia de otras morbilidades medicas como hipertensión arterial o la enfermedad renal crónica que SAAF en pacientes con preeclampsia las cuales incrementan el riesgo de presentar la enfermedad a una edad estacional más temprana