155 research outputs found

    The development of the N1 and N2 components in auditory oddball paradigms: a systematic review with narrative analysis and suggested normative values

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    Auditory event-related potentials (AERPs) are widely used in diverse fields of today’s neuroscience, concerning auditory processing, speech perception, language acquisition, neurodevelopment, attention and cognition in normal aging, gender, developmental, neurologic and psychiatric disorders. However, its transposition to clinical practice has remained minimal. Mainly due to scarce literature on normative data across age, wide spectrumof results, variety of auditory stimuli used and to different neuropsychological meanings of AERPs components between authors. One of the most prominent AERP components studied in last decades was N1, which reflects auditory detection and discrimination. Subsequently, N2 indicates attention allocation and phonological analysis. The simultaneous analysis of N1 and N2 elicited by feasible novelty experimental paradigms, such as auditory oddball, seems an objective method to assess central auditory processing. The aim of this systematic review was to bring forward normative values for auditory oddball N1 and N2 components across age. EBSCO, PubMed, Web of Knowledge and Google Scholarwere systematically searched for studies that elicited N1 and/or N2 by auditory oddball paradigm. A total of 2,764 papers were initially identified in the database, of which 19 resulted from hand search and additional references, between 1988 and 2013, last 25 years. A final total of 68 studiesmet the eligibility criteria with a total of 2,406 participants from control groups for N1 (age range 6.6–85 years; mean 34.42) and 1,507 for N2 (age range 9–85 years; mean 36.13). Polynomial regression analysis revealed thatN1latency decreases with aging at Fz and Cz,N1 amplitude at Cz decreases from childhood to adolescence and stabilizes after 30–40 years and at Fz the decrement finishes by 60 years and highly increases after this age. Regarding N2, latency did not covary with age but amplitude showed a significant decrement for both Cz and Fz. Results suggested reliable normative values for Cz and Fz electrode locations; however, changes in brain development and components topography over age should be considered in clinical practice

    Auditory event-related potentials in children with benign epilepsy with centro-temporal spikes

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    Benign focal epilepsy in childhood with centro-temporal spikes (BECTS) is one of the most common forms of idiopathic epilepsy, with onset from age 3 to 14 years. Although the prognosis for children with BECTS is excellent, some studies have revealed neuropsychological deficits in many domains, including language. Auditory event-related potentials (AERPs) reflect activation of different neuronal populations and are suggested to contribute to the evaluation of auditory discrimination (N1), attention allocation and phonological categorization (N2), and echoic memory (mismatch negativity – MMN). The scarce existing literature about this theme motivated the present study, which aims to investigate and document the existing AERP changes in a group of children with BECTS. AERPs were recorded, during the day, to pure and vocal tones and in a conventional auditory oddball paradigm in five children with BECTS (aged 8–12; mean = 10 years; male = 5) and in six gender and age-matched controls. Results revealed high amplitude of AERPs for the group of children with BECTS with a slight latency delay more pronounced in fronto-central electrodes. Children with BECTS may have abnormal central auditory processing, reflected by electrophysiological measures such as AERPs. In advance, AERPs seem a good tool to detect and reliably reveal cortical excitability in children with typical BECTS

    Bio-inspired vortex lift for enhanced manoeuvrability

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    Inspired by highly manoeuvrable species of birds like the peregrine falcon and the swift, static and dynamic computational fluid dynamics (CFD) simulations were conducted to investigate vortex lift in unsteady flows. The configuration corresponds to a 50◦ sweep delta wing with sharp leading edge at Re= 5.0×104. CFD simulations were performed using a Direct Numerical Simulation (DNS) approach with a Lattice-Boltzmann Method as well as Unsteady Reynolds Averaged Navier-Stokes (URANS) simulations. Aerodynamic forces as well as the overall structure of the leading edge vortices were compared with existing literature. The evolution of the flow structures was studied when the wing performs a pitching manoeuvre from 0◦ to 20◦ angle of attack. Close agreement between both methods was found for the static and pitching lift curves, with the URANS solver presenting substantial limitations to capture complex unsteady phenomena such as the vortex breakdown. A time lag was observed in the flow dynamics during the manoeuvre, with the vortex breakdown delayed during pitch-up resulting in an improved aerodynamics performance, but more present and intense when pitching down. A sinusoidal motion was tested with the URANS solver and compared with the linear ramp case, showing performance advantages as well as higher similarity to real manoeuvres

    InSAR Meteorology: High-Resolution Geodetic Data Can Increase Atmospheric Predictability

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    AbstractThe present study assesses the added value of high‐resolution maps of precipitable water vapor, computed from synthetic aperture radar interferograms , in short‐range atmospheric predictability. A large set of images, in different weather conditions, produced by Sentinel‐1A in a very well monitored region near the Appalachian Mountains, are assimilated by the Weather Research and Forecast (WRF) model. Results covering more than 2 years of operation indicate a consistent improvement of the water vapor predictability up to a range comparable with the transit time of the air mass in the synthetic aperture radar interferograms footprint, an overall improvement in the forecast of different precipitation events, and better representation of the spatial distribution of precipitation. This result highlights the significant potential for increasing short‐range atmospheric predictability from improved high‐resolution precipitable water vapor initial data, which can be obtained from new high‐resolution all‐weather microwave sensors

    eHealth Eurocampus: An innovative educational framework to train qualified professionals in the emerging ehealth sector

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    The aim of this paper is to present the results of an initiative called the eHealth Eurocampus (http://ehealtheurocampus.eu), whose main goal is to define a framework to prepare professionals for the eHealth work environment. To do so, three main activities have been organized: develop eHealth learning materials, international intensive study programs for both health science and IT students and international training seminars for researches and professors. The eHealth Eurocampus project is an EU-funded Erasmus+ Strategic Partnership for higher education (September-2016 / August-2019) which aims at preparing qualified professionals able to cope with the challenge of “fostering a spirit of innovation in eHealth in Europe as the way forward to ensure better health and better and safer care for EU citizens, a more skilled workforce, more efficient and sustainable health and care systems, new business opportunities” (EC eHealth Action Plan 2012-2020). The consortium of the eHealth Eurocampus project along with the participants of the designed activities have created an original eHealth teaching-learning framework where university professors, students, researchers, and clinicians are able to share their experiences and knowledge with the aim of improving the skills of graduates in order to improve their employability. These are the organized activities and the topics that have been covered: - eHealth learning materials. Five courses of 6 ECTS each have been developed in the following topics: innovation and entrepreneurship, IT for a longer independent life, robotics for health care, graphics and medical imaging and eHealth applications and tools. - Intensive study programs. Three international summer schools for both health and IT students have been organized with an interdisciplinary approach. The first one deal with innovation and entrepreneurship in eHealth. The second one is focused on applications and tools for longer independent life. And robotics, graphics and medical imaging are covered in the third one. The summer schools have proven to be the best testbed for the learning materials and for innovative teaching methodologies in interdisciplinary context. - Training seminars. When you face the training of qualified eHealth professionals it is critical to have good educators. Two training seminars have been organized with the goal of share experiences and knowledge among practitioners, university teachers and researches of the health and IT fields. The topics covered in the seminars are eHealth Teaching Challenges and Accessibility, Inclusion, and Rehabilitation using IT, respectively. In this paper, we will introduce in detail the different activities carried out, the results and conclusions of this teaching-learning framework and how the different stakeholders would take advantage of it.Postprint (author's final draft

    Grape Resveratrol Increases Serum Adiponectin and Downregulates Inflammatory Genes in Peripheral Blood Mononuclear Cells: A Triple-Blind, Placebo-Controlled, One-Year Clinical Trial in Patients with Stable Coronary Artery Disease

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    This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.[Purpose] The grape and wine polyphenol resveratrol exerts cardiovascular benefits but evidence from randomized human clinical trials is very limited. We investigated dose-depending effects of a resveratrol-containing grape supplement on stable patients with coronary artery disease (CAD) treated according to currently accepted guidelines for secondary prevention of cardiovascular disease.[Methods] In a triple-blind, randomized, placebo-controlled, one-year follow-up, 3-arm pilot clinical trial, 75 stable-CAD patients received 350 mg/day of placebo, resveratrol-containing grape extract (grape phenolics plus 8 mg resveratrol) or conventional grape extract lacking resveratrol during 6 months, and a double dose for the following 6 months. Changes in circulating inflammatory and fibrinolytic biomarkers were analyzed. Moreover, the transcriptional profiling of inflammatory genes in peripheral blood mononuclear cells (PBMCs) was explored using microarrays and functional gene expression analysis.[Results] After 1 year, in contrast to the placebo and conventional grape extract groups, the resveratrol-containing grape extract group showed an increase of the anti-inflammatory serum adiponectin (9.6 %, p = 0.01) and a decrease of the thrombogenic plasminogen activator inhibitor type 1 (PAI-1) (−18.6 %, p = 0.05). In addition, 6 key inflammation-related transcription factors were predicted to be significantly activated or inhibited, with 27 extracellular-space acting genes involved in inflammation, cell migration and T-cell interaction signals presenting downregulation (p < 0.05) in PBMCs. No adverse effects were detected in relation to the study products.[Conclusions] Chronic daily consumption of a resveratrol-containing grape nutraceutical could exert cardiovascular benefits in stable-CAD patients treated according to current evidence-based standards, by increasing serum adiponectin, preventing PAI-1 increase and inhibiting atherothrombotic signals in PBMCs.This study was supported by public funds: Projects CICYT-BFU2007-60576 and Consolider-Ingenio 2010 (CSD2007-00063, Fun-C-Food) from the Spanish Ministry of Science and Innovation (MICINN) and GERM-06-04486 (Fundación Séneca, Murcia, Spain). Dr. Tomé-Carneiro received a FPI grant from MICINN and Dr. Larrosa received a JAE-DOC contract from the Consejo Superior de Investigaciones Científicas (CSIC, Spain).Peer reviewe

    Azimuthal Asymmetry in the Risetime of the Surface Detector Signals of the Pierre Auger Observatory

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    The azimuthal asymmetry in the risetime of signals in Auger surface detector stations is a source of information on shower development. The azimuthal asymmetry is due to a combination of the longitudinal evolution of the shower and geometrical effects related to the angles of incidence of the particles into the detectors. The magnitude of the effect depends upon the zenith angle and state of development of the shower and thus provides a novel observable, (secθ)max, sensitive to the mass composition of cosmic rays above 3×1018  eV. By comparing measurements with predictions from shower simulations, we find for both of our adopted models of hadronic physics (QGSJETII-04 and EPOS-LHC) an indication that the mean cosmic-ray mass increases slowly with energy, as has been inferred from other studies. However, the mass estimates are dependent on the shower model and on the range of distance from the shower core selected. Thus the method has uncovered further deficiencies in our understanding of shower modeling that must be resolved before the mass composition can be inferred from (secθ)max.Peer Reviewe

    Testing Hadronic Interactions at Ultrahigh Energies with Air Showers Measured by the Pierre Auger Observatory

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    Ultrahigh energy cosmic ray air showers probe particle physics at energies beyond the reach of accelerators. Here we introduce a new method to test hadronic interaction models without relying on the absolute energy calibration, and apply it to events with primary energy 6-16 EeV (E_CM = 110-170 TeV), whose longitudinal development and lateral distribution were simultaneously measured by the Pierre Auger Observatory. The average hadronic shower is 1.33 +- 0.16 (1.61 +- 0.21) times larger than predicted using the leading LHC-tuned models EPOS-LHC (QGSJetII-04), with a corresponding excess of muons.Peer Reviewe

    Antennas for the Detection of Radio Emission Pulses from Cosmic-Ray

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    The Pierre Auger Observatory is exploring the potential of the radio detection technique to study extensive air showers induced by ultra-high energy cosmic rays. The Auger Engineering Radio Array (AERA) addresses both technological and scientific aspects of the radio technique. A first phase of AERA has been operating since September 2010 with detector stations observing radio signals at frequencies between 30 and 80 MHz. In this paper we present comparative studies to identify and optimize the antenna design for the final configuration of AERA consisting of 160 individual radio detector stations. The transient nature of the air shower signal requires a detailed description of the antenna sensor. As the ultra-wideband reception of pulses is not widely discussed in antenna literature, we review the relevant antenna characteristics and enhance theoretical considerations towards the impulse response of antennas including polarization effects and multiple signal reflections. On the basis of the vector effective length we study the transient response characteristics of three candidate antennas in the time domain. Observing the variation of the continuous galactic background intensity we rank the antennas with respect to the noise level added to the galactic signal.Peer Reviewe

    Nanosecond-level time synchronization of autonomous radio detector stations for extensive air showers

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    To exploit the full potential of radio measurements of cosmic-ray air showers at MHz frequencies, a detector timing synchronization within 1 ns is needed. Large distributed radio detector arrays such as the Auger Engineering Radio Array (AERA) rely on timing via the Global Positioning System (GPS) for the synchronization of individual detector station clocks. Unfortunately, GPS timing is expected to have an accuracy no better than about 5 ns. In practice, in particular in AERA, the GPS clocks exhibit drifts on the order of tens of ns. We developed a technique to correct for the GPS drifts, and an independent method is used to cross-check that indeed we reach a nanosecond-scale timing accuracy by this correction. First, we operate a ``beacon transmitter'' which emits defined sine waves detected by AERA antennas recorded within the physics data. The relative phasing of these sine waves can be used to correct for GPS clock drifts. In addition to this, we observe radio pulses emitted by commercial airplanes, the position of which we determine in real time from Automatic Dependent Surveillance Broadcasts intercepted with a software-defined radio. From the known source location and the measured arrival times of the pulses we determine relative timing offsets between radio detector stations. We demonstrate with a combined analysis that the two methods give a consistent timing calibration with an accuracy of 2 ns or better. Consequently, the beacon method alone can be used in the future to continuously determine and correct for GPS clock drifts in each individual event measured by AERA.Peer Reviewe
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