1,860 research outputs found

    Improving parsing of spontaneous speech with the help of prosodic boundaries

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    Parsing can be improved in automatic speech understanding if prosodic boundary marking is taken into account, because syntactic boundaries are often marked by prosodic means. Because large databases are needed for the training of statistical models for prosodic boundaries, we developed a labeling scheme for syntactic-prosodic boundaries within the German VERBMOBIL project (automatic speech-to-speech translation). We compare the results of classifiers (multi-layer perceptrons and language models) trained on these syntactic-prosodic boundary labels with classifiers trained on perceptual-prosodic and purely syntactic labels. Recognition rates of up to 96% were achieved. The turns that we need to parse consist of 20 words on the average and frequently contain sequences of partial sentence equivalents due to restarts, ellipsis, etc. For this material, the boundary scores computed by our classifiers can successfully be integrated into the syntactic parsing of word graphs; currently, they improve the parse time by 92% and reduce the number of parse trees by 96%. This is achieved by introducing a special Prosodic Syntactic Clause Boundary symbol (PSCB) into our grammar and guiding the search for the best word chain with the prosodic boundary scores

    Localization of a 64-kDa phosphoprotein in the lumen between the outer and inner envelopes of pea chloroplasts

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    The identification and localization of a marker protein for the intermembrane space between the outer and inner chloroplast envelopes is described. This 64-kDa protein is very rapidly labeled by [γ-32P]ATP at very low (30 nM) ATP concentrations and the phosphoryl group exhibits a high turnover rate. It was possible to establish the presence of the 64-kDa protein in this plastid compartment by using different chloroplast envelope separation and isolation techniques. In addition comparison of labeling kinetics by intact and hypotonically lysed pea chloroplasts support the localization of the 64-kDa protein in the intermembrane space. The 64-kDa protein was present and could be labeled in mixed envelope membranes isolated from hypotonically lysed plastids. Mixed envelope membranes incorporated high amounts of 32P from [γ-32P]ATP into the 64-kDa protein, whereas separated outer and inner envelope membranes did not show significant phosphorylation of this protein. Water/Triton X-114 phase partitioning demonstrated that the 64-kDa protein is a hydrophilic polypeptide. These findings suggest that the 64-kDa protein is a soluble protein trapped in the space between the inner and outer envelope membranes. After sonication of mixed envelope membranes, the 64-kDa protein was no longer present in the membrane fraction, but could be found in the supernatant after a 110000 × g centrifugation

    Analytic models and forward scattering from accelerator to cosmic-ray energies

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    Analytic models for hadron-hadron scattering are characterized by analytical parametrizations for the forward amplitudes and the use of dispersion relation techniques to study the total cross section σtot\sigma_{tot} and the ρ\rho parameter. In this paper we investigate four aspects related to the application of the model to pppp and pˉp\bar{p}p scattering, from accelerator to cosmic-ray energies: 1) the effect of different estimations for σtot\sigma_{tot} from cosmic-ray experiments; 2) the differences between individual and global (simultaneous) fits to σtot\sigma_{tot} and ρ\rho; 3) the role of the subtraction constant in the dispersion relations; 4) the effect of distinct asymptotic inputs from different analytic models. This is done by using as a framework the single Pomeron and the maximal Odderon parametrizations for the total cross section. Our main conclusions are the following: 1) Despite the small influence from different cosmic-ray estimations, the results allow us to extract an upper bound for the soft pomeron intercept: 1+ϵ=1.0941 + \epsilon = 1.094; 2) although global fits present good statistical results, in general, this procedure constrains the rise of σtot\sigma_{tot}; 3) the subtraction constant as a free parameter affects the fit results at both low and high energies; 4) independently of the cosmic-ray information used and the subtraction constant, global fits with the odderon parametrization predict that, above s70\sqrt s \approx 70 GeV, ρpp(s)\rho_{pp}(s) becomes greater than ρpˉp(s)\rho_{\bar{p}p}(s), and this result is in complete agreement with all the data presently available. In particular, we infer ρpp=0.134±0.005\rho_{pp} = 0.134 \pm 0.005 at s=200\sqrt s = 200 GeV and 0.151±0.0070.151 \pm 0.007 at 500 GeV (BNL RHIC energies).Comment: 16 pages, 7 figures, aps-revtex, wording changes, corrected typos, to appear in Physical Review

    Survival probability for exclusive central diffractive production of colorless states at the LHC

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    In this paper we discuss the survival probability for exclusive central diffractive production of a colorless small size system at the LHC. This process has a clear signature of two large rapidity gaps. Using the eikonal approach for the description of soft interactions, we predict the value of the survival probability to be about 5~6% for single channel models, while for a two channel model the survival probability is about 3%. The dependence of the survival probability factor (damping factor) on the transverse momenta of the recoiled protons is discussed, and we suggest it be measured at the Tevatron so as to minimize the possible ambiguity in the calculation of survival probability at the LHC.Comment: 33 pages, 26 figure

    Effects of thermal fluctuation and the receptor-receptor interaction in bacterial chemotactic signalling and adaptation

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    Bacterial chemotaxis is controlled by the conformational changes of the receptors, in response to the change of the ambient chemical concentration. In a statistical mechanical approach, the signalling due to the conformational changes is a thermodynamic average quantity, dependent on the temperature and the total energy of the system, including both ligand-receptor interaction and receptor-receptor interaction. This physical theory suggests to biology a new understanding of cooperation in ligand binding and receptor signalling problems. How much experimental support of this approach can be obtained from the currently available data? What are the parameter values? What is the practical information for experiments? Here we make comparisons between the theory and recent experimental results. Although currently comparisons can only be semi-quantitative or qualitative, consistency is clearly shown. The theory also helps to sort a variety of data.Comment: 26 pages, revtex. Journal version. Analysis on another set of data on adaptation time is adde

    Dust in Spiral Galaxies: Comparing Emission and Absorption to Constrain Small-Scale and Very Cold Structures

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    The detailed distribution of dust in the disks of spiral galaxies is important to understanding the radiative transfer within disks, and to measuring overall dust masses if significant quantities of dust are either very opaque or very cold. We address this issue by comparing measures of dust absorption, using the galaxy-overlap technique in the optical, with measures of the dust grains' thermal emission from 50-2000 micron using ISOPHOT on board ISO and SCUBA at the JCMT. We examine three spiral galaxies projected partially in front of E/S0 galaxies --- AM1316-241, NGC 5545, and NGC 5091 (for NGC 5091 we have only optical and ISO data). Adopting an empirical exponential model for the dust distribution, we compare column densities and dust masses derived from the absorption and emission techniques. This comparison is sensitive to the amount of dust mass in small, opaque structures, which would not contribute strongly to area-weighted absorption measures, and to very cold dust, which would contribute to optical absorption but provide only a small fraction of the sub-mm emission. In AM1316-241, we find global dust masses of 2-5 x 10^7 M_solar, both techniques agreeing at the 50% level. NGC 5545 has about half this dust mass. The concordance of dust masses is well within the errors expected from our knowledge of the radial distribution of dust, and argues against any dominant part of the dust mass being so cold or opaque. The 50-2000 micron data are well fitted by modified Planck functions with an emissivity law beta=-2, at 21 +/- 2 K. We also present 12 micron ISOCAM observations of these pairs.Comparison of H-alpha and 12 micron images of NGC 5545 indicate that ISOCAM images are reliable tracers of star formation.Comment: 16 pages, 4 tables, 8 figures, in press for October Astronomical Journa

    Personhood, consciousness, and god : how to be a proper pantheist

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    © Springer Nature B.V. 2018In this paper I develop a theory of personhood which leaves open the possibility of construing the universe as a person. If successful, it removes one bar to endorsing pantheism. I do this by examining a rising school of thought on personhood, on which persons, or selves, are understood as identical to episodes of consciousness. Through a critique of this experiential approach to personhood, I develop a theory of self as constituted of qualitative mental contents, but where these contents are also capable of unconscious existence. On this theory, though we can be conscious of our selves, consciousness turns out to be inessential to personhood. This move, I then argue, provides resources for responding to the pantheist’s problem of God’s person.Peer reviewedFinal Accepted Versio

    NS1 Specific CD8(+) T-Cells with Effector Function and TRBV11 Dominance in a Patient with Parvovirus B19 Associated Inflammatory Cardiomyopathy

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    Background: Parvovirus B19 (B19V) is the most commonly detected virus in endomyocardial biopsies (EMBs) from patients with inflammatory cardiomyopathy (DCMi). Despite the importance of T-cells in antiviral defense, little is known about the role of B19V specific T-cells in this entity. Methodology and Principal Findings: An exceptionally high B19V viral load in EMBs (115,091 viral copies/mg nucleic acids), peripheral blood mononuclear cells (PBMCs) and serum was measured in a DCMi patient at initial presentation, suggesting B19V viremia. The B19V viral load in EMBs had decreased substantially 6 and 12 months afterwards, and was not traceable in PBMCs and the serum at these times. Using pools of overlapping peptides spanning the whole B19V proteome, strong CD8(+) T-cell responses were elicited to the 10-amico-acid peptides SALKLAIYKA (19.7% of all CD8(+) cells) and QSALKLAIYK (10%) and additional weaker responses to GLCPHCINVG (0.71%) and LLHTDFEQVM (0.06%). Real-time RT-PCR of IFN gamma secretion-assay-enriched T-cells responding to the peptides, SALKLAIYKA and GLCPHCINVG, revealed a disproportionately high T-cell receptor Vbeta (TRBV) 11 expression in this population. Furthermore, dominant expression of type-1 (IFN gamma, IL2, IL27 and Tbet) and of cytotoxic T-cell markers (Perforin and Granzyme B) was found, whereas gene expression indicating type-2 (IL4, GATA3) and regulatory T-cells (FoxP3) was low. Conclusions: Our results indicate that B19V Ag-specific CD8(+) T-cells with effector function are involved in B19V associated DCMi. In particular, a dominant role of TRBV11 and type-1/CTL effector cells in the T-cell mediated antiviral immune response is suggested. The persistence of B19V in the endomyocardium is a likely antigen source for the maintenance of CD8(+) T-cell responses to the identified epitopes

    SPITZER SAGE Observations of Large Magellanic Cloud Planetary Nebulae

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    We present IRAC and MIPS images and photometry of a sample of previously known planetary nebulae (PNe) from the SAGE survey of the Large Magellanic Cloud (LMC) performed with the Spitzer Space Telescope. Of the 233 known PNe in the survey field, 185 objects were detected in at least two of the IRAC bands, and 161 detected in the MIPS 24 micron images. Color-color and color-magnitude diagrams are presented using several combinations of IRAC, MIPS, and 2MASS magnitudes. The location of an individual PN in the color-color diagrams is seen to depend on the relative contributions of the spectral components which include molecular hydrogen, polycyclic aromatic hydrocarbons (PAHs), infrared forbidden line emission from the ionized gas, warm dust continuum, and emission directly from the central star. The sample of LMC PNe is compared to a number of Galactic PNe and found to not significantly differ in their position in color-color space. We also explore the potential value of IR PNe luminosity functions (LFs) in the LMC. IRAC LFs appear to follow the same functional form as the well-established [O III] LFs although there are several PNe with observed IR magnitudes brighter than the cut-offs in these LFs.Comment: 18 pages, 10 figures, 3 tables, to be published in the Astronomical Journal. Additional online data available at http://www.cfa.harvard.edu/irac/publications
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