259 research outputs found

    Quantitative EEG parameters correlate with the progression of human prion diseases

    Get PDF
    BACKGROUND: Prion diseases are universally fatal and often rapidly progressive neurodegenerative diseases. EEG has long been used in the diagnosis of sporadic Creutzfeldt-Jakob disease; however, the characteristic waveforms do not occur in all types of prion diseases. Here, we re-evaluate the utility of EEG by focusing on the development of biomarkers. We test whether abnormal quantitative EEG parameters can be used to measure disease progression in prion diseases or predict disease onset in healthy individuals at risk of disease. METHODS: In the National Prion Monitoring Cohort study, we did quantitative encephalography on 301 occasions in 29 healthy controls and 67 patients with prion disease. The patients had either inherited prion disease or sporadic Creutzfeldt-Jakob disease. We computed the main background frequency, the α and θ power and the α/θ power ratio, then averaged these within 5 electrode groups. These measurements were then compared among participant groups and correlated with functional and cognitive scores cross-sectionally and longitudinally. RESULTS: We found lower main background frequency, α power and α/θ power ratio and higher θ power in patients compared to control participants. The main background frequency, the power in the α band and the α/θ power ratio also differed in a consistent way among the patient groups. Moreover, the main background frequency and the α/θ power ratio correlated significantly with functional and cognitive scores. Longitudinally, change in these parameters also showed significant correlation with the change in clinical and cognitive scores. CONCLUSIONS: Our findings support the use of quantitative EEG to follow the progression of prion disease, with potential to help evaluate the treatment effects in future clinical-trials

    Radiative corrections to polarization observables in elastic electron-deuteron scattering in leptonic variables

    Full text link
    The model--independent QED radiative corrections to polarization observables in elastic scattering of unpolarized and longitudinally--polarized electron beam by the deuteron target have been calculated in leptonic variables. The experimental setup when the deuteron target is arbitrarily polarized is considered and the procedure for applying derived results to the vector or tensor polarization of the recoil deuteron is discussed. The basis of the calculations consists of the account for all essential Feynman diagrams which results in the form of the Drell-Yan representation for the cross-section and use of the covariant parametrization of the deuteron polarization state. The numerical estimates of the radiative corrections are given for the case when event selection allows the undetected particles (photons and electron-positron pairs) and the restriction on the lost invariant mass is used.Comment: 43 pages,3 figures. To be published in ZhTEF. revised 14.02.2012. arXiv admin note: text overlap with arXiv:nucl-ex/0002003 by other author

    Simultaneous wavelength and orbital angular momentum demultiplexing using tunable MEMS-based Fabry-Perot filter

    Get PDF
    In this paper, we experimentally demonstrate simultaneous wavelength and orbital angular momentum (OAM) multiplexing/demultiplexing of 10 Gbit/s data streams using a new on-chip micro-component – tunable MEMS-based Fabry-Perot filter integrated with a spiral phase plate. In the experiment, two wavelengths, each of them carrying two channels with zero and nonzero OAMs, form four independent information channels. In case of spacing between wavelength channels of 0.8 nm and intensity modulation, power penalties relative to the transmission of one channel do not exceed 1.45, 0.79 and 0.46 dB at the harddecision forward-error correction (HD-FEC) bit-error-rate (BER) limit 3.8 × 10¯³ when multiplexing a Gaussian beam and OAM beams of azimuthal orders 1, 2 and 3 respectively. In case of phase modulation, power penalties do not exceed 1.77, 0.54 and 0.79 dB respectively. At the 0.4 nm wavelength grid, maximum power penalties at the HD-FEC BER threshold relative to the 0.8 nm wavelength spacing read 0.83, 0.84 and 1.15 dB when multiplexing a Gaussian beam and OAM beams of 1st, 2nd and 3rd orders respectively. The novelty and impact of the proposed filter design is in providing practical, integrable, cheap, and reliable transformation of OAM states simultaneously with the selection of a particular wavelength in wavelength division multiplexing (WDM). The proposed on-chip device can be useful in future high-capacity optical communications with spatial- and wavelengthdivision multiplexing, especially for short-range communication links and optical interconnects

    Identificación de las prioridades nacionales de investigación en COVID-19 (SARS-CoV-2) y otros virus respiratorios con potencial pandémico: Descripción del proceso peruano

    Get PDF
    Research priorities are a fundamental component of national health research systems. In the year 2021, the National Institute of Health led the process of identifying the "national research priorities in COVID-19 (SARS-CoV-2) and other respiratory viruses with pandemic potential: Preparing for the next pandemic, 2022-2026”. The process was developed following the previous methodology for identification of research priorities used by the Instituto Nacional de Salud (Perú), which was to be adapted to a virtual environment, with four phases. Six strategic objectives to be achieved were formulated and served as an umbrella for the identification of national priorities, a total of 21 research priorities were identified. It is recommended that a plan for the implementation of research priorities be formulated and executed and that the Ministry of Health, through its different instances, take the necessary steps to obtain and allocate resources to the generation of evidence within the framework of priorities.Las prioridades de investigación son un componente fundamental de los sistemas nacionales de investigación en salud. En el año 2021, el Instituto Nacional de Salud lideró el proceso de identificación de las “prioridades nacionales de investigación en COVID-19 (SARS-CoV-2) y otros virus respiratorios con potencial pandémico: Preparándonos para la siguiente pandemia, 2022-2026”. El proceso siguió la metodología previamente utilizada por el Instituto Nacional de Salud (Perú) para la identificación de prioridades de identificación, la que se tuvo que adaptar a un entorno totalmente virtual, con cuatro fases. Se formularon seis objetivos estratégicos a alcanzar y que sirvieron de paraguas para la identificación de las prioridades nacionales, se identificaron en total 21 prioridades de investigación. Se recomienda se formule y ejecute un plan de implementación de las prioridades de investigación y que el Ministerio de Salud a través de sus diferentes instancias realice las gestiones necesarias para conseguir y destinar recursos a la generación de evidencia en el marco de las prioridades
    corecore