345 research outputs found

    Enhanced transmission of slit arrays in an extremely thin metallic film

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    Horizontal resonances of slit arrays are studied. They can lead to an enhanced transmission that cannot be explained using the single-mode approximation. A new type of cavity resonance is found when the slits are narrow for a wavelength very close to the period. It can be excited for very low thicknesses. Optimization shows these structures could constitute interesting monochromatic filters

    Acoustic, psychophysical, and neuroimaging measurements of the effectiveness of active cancellation during auditory functional magnetic resonance imaging

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    Functional magnetic resonance imaging (fMRI) is one of the principal neuroimaging techniques for studying human audition, but it generates an intense background sound which hinders listening performance and confounds measures of the auditory response. This paper reports the perceptual effects of an active noise control (ANC) system that operates in the electromagnetically hostile and physically compact neuroimaging environment to provide significant noise reduction, without interfering with image quality. Cancellation was first evaluated at 600 Hz, corresponding to the dominant peak in the power spectrum of the background sound and at which cancellation is maximally effective. Microphone measurements at the ear demonstrated 35 dB of acoustic attenuation [from 93 to 58 dB sound pressure level (SPL)], while masked detection thresholds improved by 20 dB (from 74 to 54 dB SPL). Considerable perceptual benefits were also obtained across other frequencies, including those corresponding to dips in the spectrum of the background sound. Cancellation also improved the statistical detection of sound-related cortical activation, especially for sounds presented at low intensities. These results confirm that ANC offers substantial benefits for fMRI research

    Pulsar Timing with the Parkes Radio Telescope for the Fermi Mission

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    We report here on two years of timing of 168 pulsars using the Parkes radio telescope. The vast majority of these pulsars have spin-down luminosities in excess of 10^34 erg/s and are prime target candidates to be detected in gamma-rays by the Fermi Gamma-Ray Space Telescope. We provide the ephemerides for the ten pulsars being timed at Parkes which have been detected by Fermi in its first year of operation. These ephemerides, in conjunction with the publicly available photon list, can be used to generate gamma-ray profiles from the Fermi archive. We will make the ephemerides of any pulsars of interest available to the community upon request. In addition to the timing ephemerides, we present the parameters for 14 glitches which have occurred in 13 pulsars, seven of which have no previously known glitch history. The Parkes timing programme, in conjunction with Fermi observations, is expected to continue for at least the next four years.Comment: Accepted for publication in PASA.12 page

    Структурные изменения в системе гемостаза у больных меланомой кожи на ранней стадии ее развития

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    Мета дослідження – оцінка показників системи гемостазу у 27 хворих на меланому шкіри. Виявлено подовження активованого часткового тромбопластинового часу, подовження часткового тромбопластинового часу, подовження часу рекальцифікації, зниження рівня антитромбіну III, підвищення рівня розчинних фібрін-мономерних комплексів. Таким чином, мають місце серйозні структурні зміни системного гемостазу - гіпокоагуляція і гіперфібриноліз. Діагностика та корекція цих змін допоможе поліпшити клінічний перебіг і прогноз захворювання.A research aim is an estimation of indexes of the system of hemostasis at 27 patients by the melanoma of skin. Lengthening of the activated partial tromboplastin time, lengthening of partial tromboplastin time, lengthening of time of recalcification, decline of level of antithrombin of III, increase of level of soluble fibrinmonomers complexes is educed. Thus, the serious structural changes in the system of hemostasis - incoagulability and hyperfibrinolysis take place. Diagnostics and correction of these changes will help to improve a clinical flow and prognosis of disease

    600 MW FUSED SALT HOMOGENEOUS REACTOR POWER PLANT. Reactor Design and Feasibility Study

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    This report is a study of the feasibility of using a fused salt fuel reactor in a central station electric generating plant

    Infection-mediated priming of phagocytes protects against lethal secondary Aspergillus fumigatus challenge

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    Phagocytes restrict the germination of Aspergillus fumigatus conidia and prevent the establishment of invasive pulmonary aspergillosis in immunecompetent mice. Here we report that immunecompetent mice recovering from a primary A. fumigatus challenge are protected against a secondary lethal challenge. Using RAGγc knock-out mice we show that this protection is independent of T, B and NK cells. In protected mice, lung phagocytes are recruited more rapidly and are more efficient in conidial phagocytosis and killing. Protection was also associated with an enhanced expression of CXCR2 and Dectin-1 on bone marrow phagocytes. We also show that protective lung cytokine and chemokine responses are induced more rapidly and with enhanced dynamics in protected mice. Our findings support the hypothesis that following a first encounter with a non-lethal dose of A. fumigatus conidia, the innate immune system is primed and can mediate protection against a secondary lethal infection

    The Parkes Observatory Pulsar Data Archive

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    The Parkes pulsar data archive currently provides access to 144044 data files obtained from observations carried out at the Parkes observatory since the year 1991. Around 10^5 files are from surveys of the sky, the remainder are observations of 775 individual pulsars and their corresponding calibration signals. Survey observations are included from the Parkes 70cm and the Swinburne Intermediate Latitude surveys. Individual pulsar observations are included from young pulsar timing projects, the Parkes Pulsar Timing Array and from the PULSE@Parkes outreach program. The data files and access methods are compatible with Virtual Observatory protocols. This paper describes the data currently stored in the archive and presents ways in which these data can be searched and downloaded.Comment: Accepted by PAS
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