7 research outputs found

    Readiness Potential in Parkinson's Disease: Effects of L-Dopa Therapy and Brain Transplants

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    Accurate local positioning systems usually use a network of anchor nodes at known locations to track mobile nodes based on the measurement of the time of arrival (TOA) at anchor nodes of beacon signals transmitted by the mobile nodes. To localize the mobile node either TOA processing, where the unknown transmit time is estimated along with the node location, or time difference of arrival (TDOA) processing, where the transmit time is eliminated before estimating the node location, can be used. We show that the position error bound of both these formulations are the same by analyzing the Cramér-Rao lower bound. When processing data collected in field trials, however, we observed that the TOA processing yields better localization accuracy, and explain this behavior using differential geometry-based curvature measures that show that the TDOA cost function has greater degree of non-linearity.T. Sathyan, M. Hedley, M. Mallic

    Changes in Attention to an Emotional Task after Sleep Deprivation: Neurophysiological and Behavioral Findings

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    While sleep loss is shown to have widespread effects on cognitive processes, little is known about the impact of sleep loss on emotion processes. In order to expand on previous behavioral and physiological findings on how sleep loss influences emotion processing, we administered positive, negative, and neutral affective visual stimuli to individuals after one night of sleep deprivation while simultaneously acquiring EEG event related potential (ERP) data and recording affective behavioral responses. We compared these responses to a baseline testing session. We specifically looked at the late positive potential (LPP) component of the visual ERP as an established sensitive measure of attention to emotionally-charged visual stimuli. Our results show that after sleep deprivation, the LPP no longer discriminates between emotional and non-emotional pictures; after sleep deprivation the LPP amplitude was of similar amplitude for neutral, positive, and negative pictures. This effect was driven by an increase in the LPP to neutral pictures. Our behavioral measures show that, relative to baseline testing, emotional pictures are rated as less emotional following sleep deprivation with a concomitant reduction in emotional picture-induced anxiety. We did not observe any change in cortisol concentrations after sleep deprivation before or after emotional picture exposure, suggesting that the observed changes in emotion processing are independent of potential stress effects of sleep deprivation. Combined, our findings suggest that sleep loss interferes with proper allocation of attention resources during an emotional task

    Uterine rupture during pregnancy: The URIDA (uterine rupture international data acquisition) study

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    Objective: To describe the characteristics and peripartum outcomes of patients diagnosed with uterine rupture (UR) by an observational cohort retrospective study on 270 patients. Methods: Demographic information, surgical history, symptoms, and postoperative outcome of women and neonates after UR were collected in a large database. The statistical analysis searched for correlation between UR, previous uterine interventions, fibroids, and the successive perinatal outcomes in women with previous UR. Results: Uterine rupture was significantly associated with previous uterine surgery, occurring, on average, at 36 weeks of pregnancy in women also without previous uterine surgery. UR did not rise exponentially with an increasing number of uterine operations. Fibroids were related to UR. The earliest UR occurred at 159 days after hysteroscopic myomectomy, followed by laparoscopic myomectomy (251 days) and laparotomic myomectomy (253 days). Fertility preservation was feasible in several women. Gestational age and birth weight seemed not to be affected in the subsequent pregnancy. Conclusion: Data analysis showed that previous laparoscopic and abdominal myomectomies were associated with UR in pregnancy, and hysteroscopic myomectomy was associated at earlier gestational ages. UR did not increase exponentially with an increasing number of previous scars. UR should not be considered a contraindication to future pregnancies
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