12,107 research outputs found

    Report on the EU-US Workshop on Large Scientific Databases

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    This joint workshop was set up under the auspices of the Joint European Commission/National Science Foundation Strategy Group that met in Budapest in September 1998. The meeting derived from a joint collaboration agreement between the EC and NSF, signed by Dr. George Metakides (Director of Information Technologies for the EC) and Prof. Juris Hartmanis (Director of Computer and Information Science and Engineering at the NSF). Some themes that were identified include: digital libraries human-centered computing and virtual environments large scientific databases, and intelligent implants This report expresses the conclusions and recommendations of the Workshop on Large Scientific Databases, held in Annapolis, Maryland, USA in September 1999. The purpose of the workshop was to develop a report to the funding agencies outlining a possible solicitation to the research community, with emphasis on joint European-US work on Large Scientific Databases. Before the workshop, each participant submitted a position paper (these are available at the web site http://www.cacr.caltech.edu/euus). The results of the position papers, presentations, and group discussion are summarized in this report. There were 12 participants from Europe and 12 from the United States, and they are listed at the end of this report. The last section of this report describes possible funding mechanisms

    Isotope analysis of water by means of near-infrared dual-wavelength diode laser spectroscopy

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    A novel diode laser spectrometer was developed using dual-wavelength multiplexing, ensuring ideal conditions for high-precision and simultaneous measurements of the 2H/1H, 17O/16O, and 18O/16O isotope ratios in water. A 1.4-µm diode laser probed a H16OH/HO2H line pair near 7198 cm-1, while a similar laser observed H16OH, H17OH, and H18OH ro-vibrational lines around 7183 cm-1, or a H16OH/H18OH line pair near 7200 cm–1. The 1-σ standard deviation is 0.2‰ for 18O/16O, and 0.5‰ for the 2H/1H and 17O/16O isotope ratios. Preliminary experiments with repeated injections of a natural abundance sample point to an accuracy of about 1‰ for all three isotope ratios in natural samples.

    Phenomenological interpolation of the inclusive J/psi cross section to proton-proton collisions at 2.76 TeV and 5.5 TeV

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    We present a study of the inclusive J/psi cross section at 2.76 TeV and 5.5 TeV. The energy dependence of the cross section, rapidity and transverse momentum distributions are evaluated phenomenologically. Their knowledge is crucial as a reference for the interpretation of A-A and p-A J/psi results at the LHC. Our approach is the following: first, we estimate the energy evolution of the pt-integrated J/psi cross section at mid-rapidity; then, we evaluate the rapidity dependence; finally, we study the transverse momentum distribution trend. Whenever possible, both theory driven (based on pQCD predictions) and functional form (data driven fits) calculations are discussed. Our predictions are compared with the recently obtained results by the ALICE collaboration in pp collisions at 2.76 TeV.Comment: 23 pages, 19 figures, updated text+figures, added comparison to ALICE measurements at 2.76Te

    Absolute absorption and fluorescence measurements over a dynamic range of 106^6 with cavity-enhanced laser-induced fluorescence

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    We describe a novel experimental setup that combines the advantages of both laser-induced fluorescence and cavity ring-down techniques. The simultaneous and correlated measurement of the ring-down and fluorescence signals yields absolute absorption coefficients for the fluorescence measurement. The combined measurement is conducted with the same sample in a single, pulsed laser beam. The fluorescence measurement extends the dynamic range of a stand-alone cavity ring-down setup from typically three to at least six orders of magnitude. The presence of the cavity improves the quality of the signal, in particular the signal-to-noise ratio. The methodology, dubbed cavity-enhanced laser-induced fluorescence (CELIF), is developed and rigorously tested against the spectroscopy of 1,4-bis(phenylethynyl)benzene in a molecular beam and density measurements in a cell. We outline how the method can be utilised to determine absolute quantities: absorption cross sections, sample densities and fluorescence quantum yields.Comment: 12 pages, 6 figures, submitted to J. Chem. Phy

    A combinatorial smoothness criterion for spherical varieties

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    We suggest a combinatorial criterion for the smoothness of an arbitrary spherical variety using the classification of multiplicity-free spaces, generalizing an earlier result of Camus for spherical varieties of type AA.Comment: 14 pages, 2 table

    Resonant electron heating and molecular phonon cooling in single C60_{60} junctions

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    We study heating and heat dissipation of a single \c60 molecule in the junction of a scanning tunneling microscope (STM) by measuring the electron current required to thermally decompose the fullerene cage. The power for decomposition varies with electron energy and reflects the molecular resonance structure. When the STM tip contacts the fullerene the molecule can sustain much larger currents. Transport simulations explain these effects by molecular heating due to resonant electron-phonon coupling and molecular cooling by vibrational decay into the tip upon contact formation.Comment: Accepted in Phys. Rev. Let

    Asymptotic normalization coefficient of ^{8}B from breakup reactions and the S_{17} astrophysical factor

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    We show that asymptotic normalization coefficients (ANC) can be extracted from one nucleon breakup reactions of loosely bound nuclei at 30-300 MeV/u. In particular, the breakup of ^{8}B is described in terms of an extended Glauber model. The 8B ANC extracted for the ground state of this nucleus from breakup data at several energies and on different targets, C^2 = 0.450+/-0.039} fm^-1, leads to the astrophysical factor S_{17}(0)= 17.4+/-1.5 eVb for the key reaction for solar neutrino production 7Be(p,gamma)8B. The procedure described here is more general, providing an indirect method to determine reaction rates of astrophysical interest with beams of loosely bound radioactive nuclei.Comment: 4 pages, RevTex, 3 figures revised version to appear in Phys Rev Let

    Linguistic biomarkers for the detection of Mild Cognitive Impairment

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    A timely diagnosis of the prodromal stages of dementia remains a big challenge for healthcare systems: many assessment tools have been proposed over recent years, but the commonest screening instruments are largely unreliable for detecting subtle changes in cognition. The scientific literature contains a rising number of reports about language disturbances at the earliest stages of dementia, a clinical syndrome known as “Mild Cognitive Impairment" (MCI). Here we take advantage of these findings to develop a novel NLP method capable of identifying cognitive frailty at a very early stage by processing Italian spoken productions. This study constitutes a first step in the creation of an automatic tool for non-intrusive, low-cost dementia screening exploiting linguistic biomarkers. Our findings show that acoustic features (i.e., fluency indexes and spectral properties of the voice) are the most reliable parameters for MCI early identification. Moreover, lexical and syntactic features, grabbing the erosion of verbal abilities caused by the pathology, emerge as statistically significant and can support speech traits in the classification process
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