12,814 research outputs found

    Learning Optimal Deep Projection of 18^{18}F-FDG PET Imaging for Early Differential Diagnosis of Parkinsonian Syndromes

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    Several diseases of parkinsonian syndromes present similar symptoms at early stage and no objective widely used diagnostic methods have been approved until now. Positron emission tomography (PET) with 18^{18}F-FDG was shown to be able to assess early neuronal dysfunction of synucleinopathies and tauopathies. Tensor factorization (TF) based approaches have been applied to identify characteristic metabolic patterns for differential diagnosis. However, these conventional dimension-reduction strategies assume linear or multi-linear relationships inside data, and are therefore insufficient to distinguish nonlinear metabolic differences between various parkinsonian syndromes. In this paper, we propose a Deep Projection Neural Network (DPNN) to identify characteristic metabolic pattern for early differential diagnosis of parkinsonian syndromes. We draw our inspiration from the existing TF methods. The network consists of a (i) compression part: which uses a deep network to learn optimal 2D projections of 3D scans, and a (ii) classification part: which maps the 2D projections to labels. The compression part can be pre-trained using surplus unlabelled datasets. Also, as the classification part operates on these 2D projections, it can be trained end-to-end effectively with limited labelled data, in contrast to 3D approaches. We show that DPNN is more effective in comparison to existing state-of-the-art and plausible baselines.Comment: 8 pages, 3 figures, conference, MICCAI DLMIA, 201

    Ages and Masses of 0.64 million Red Giant Branch stars from the LAMOST Galactic Spectroscopic Survey

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    We present a catalog of stellar age and mass estimates for a sample of 640\,986 red giant branch (RGB) stars of the Galactic disk from the LAMOST Galactic Spectroscopic Survey (DR4). The RGB stars are distinguished from the red clump stars utilizing period spacing derived from the spectra with a machine learning method based on kernel principal component analysis (KPCA). Cross-validation suggests our method is capable of distinguishing RC from RGB stars with only 2 per cent contamination rate for stars with signal-to-noise ratio (SNR) higher than 50. The age and mass of these RGB stars are determined from their LAMOST spectra with KPCA method by taking the LAMOST - KeplerKepler giant stars having asteroseismic parameters and the LAMOST-TGAS sub-giant stars based on isochrones as training sets. Examinations suggest that the age and mass estimates of our RGB sample stars with SNR >> 30 have a median error of 30 per cent and 10 per cent, respectively. Stellar ages are found to exhibit positive vertical and negative radial gradients across the disk, and the age structure of the disk is strongly flared across the whole disk of 6<R<136<R<13\,kpc. The data set demonstrates good correlations among stellar age, [Fe/H] and [α\alpha/Fe]. There are two separate sequences in the [Fe/H] -- [α\alpha/Fe] plane: a high--α\alpha sequence with stars older than \sim\,8\,Gyr and a low--α\alpha sequence composed of stars with ages covering the whole range of possible ages of stars. We also examine relations between age and kinematic parameters derived from the Gaia DR2 parallax and proper motions. Both the median value and dispersion of the orbital eccentricity are found to increase with age. The vertical angular momentum is found to fairly smoothly decrease with age from 2 to 12\,Gyr, with a rate of about -50\,kpc\,km\,s1^{-1}\,Gyr1^{-1}. A full table of the catalog is public available online.Comment: 16 pages, 22 figures,accepted by MNRA

    Simulation of Light Antinucleus-Nucleus Interactions

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    Creations of light anti-nuclei (anti-deuterium, anti-tritium, anti-He3 and anti-He4) are observed by collaborations at the LHC and RHIC accelerators. Some cosmic ray experiments are aimed to find the anti-nuclei in cosmic rays. To support the experimental studies of the anti-nuclei a Monte Carlo simulation of anti-nuclei interactions with matter is implemented in the Geant4 toolkit. The implementation combines practically all known theoretical approaches to the problem of antinucleon-nucleon interactions.Comment: 8 pages, 5 figure

    Induced magnetization in La0.7_{0.7}Sr0.3_{0.3}MnO3_3/BiFeO3_3 superlattices

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    Using polarized neutron reflectometry (PNR), we observe an induced magnetization of 75±\pm 25 kA/m at 10 K in a La0.7_{0.7}Sr0.3_{0.3}MnO3_3 (LSMO)/BiFeO3_3 superlattice extending from the interface through several atomic layers of the BiFeO3_3 (BFO). The induced magnetization in BFO is explained by density functional theory, where the size of bandgap of BFO plays an important role. Considering a classical exchange field between the LSMO and BFO layers, we further show that magnetization is expected to extend throughout the BFO, which provides a theoretical explanation for the results of the neutron scattering experiment.Comment: 5 pages, 4 figures, with Supplemental Materials. To appear in Physical Review Letter

    W3 Is a New Wax Locus That Is Essential for Biosynthesis of beta-Diketone, Development of Glaucousness, and Reduction of Cuticle Permeability in Common Wheat

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    Citation: Zhang, Z. Z., Wei, W. J., Zhu, H. L., Challa, G. S., Bi, C. L., Trick, H. N., & Li, W. L. (2015). W3 Is a New Wax Locus That Is Essential for Biosynthesis of beta-Diketone, Development of Glaucousness, and Reduction of Cuticle Permeability in Common Wheat. Plos One, 10(10), 21. doi:10.1371/journal.pone.0140524The cuticle plays important roles in plant development, growth and defense against biotic and abiotic attacks. Crystallized epicuticular wax, the outermost layer of cuticle, is visible as white-bluish glaucousness. In crops like barley and wheat, glaucousness is trait of adaption to the dry and hot cultivation conditions, and hentriacontane-14,16-dione (beta-diketone) and its hydroxy derivatives are the major and unique components of cuticular wax in the upper parts of adult plants. But their biosynthetic pathway and physiological role largely remain unknown. In the present research, we identified a novel wax mutant in wheat cultivar Bobwhite. The mutation is not allelic to the known wax production gene loci W1 and W2, and designated as W3 accordingly. Genetic analysis localized W3 on chromosome arm 2BS. The w3 mutation reduced 99% of beta-diketones, which account for 63.3% of the total wax load of the wild-type. W3 is necessary for beta-diketone synthesis, but has a different effect on beta-diketone hydroxylation because the hydroxy-beta-diketones to beta-diketone ratio increased 11-fold in the w3 mutant. Loss of beta-diketones caused failure to form glaucousness and significant increase of cuticle permeability in terms of water loss and chlorophyll efflux in the w3 mutant. Transcription of 23 cuticle genes from five functional groups was altered in the w3 mutant, 19 down-regulated and four up-regulated, suggesting a possibility that W3 encodes a transcription regulator coordinating expression of cuticle genes. Biosynthesis of beta-diketones in wheat and their implications in glaucousness formation and drought and heat tolerance were discussed.Citation: Zhang, Z., . . . & Wanlong, Li. (2015). W3 Is a New Wax Locus That Is Essential for Biosynthesis of β-Diketone, Development of Glaucousness, and Reduction of Cuticle Permeability in Common Wheat. PLoS One, 10(10), 1-21. https://doi.org/10.1371/journal.pone.014052

    Degenerate Rotating Black Holes, Chiral CFTs and Fermi Surfaces I - Analytic Results for Quasinormal Modes

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    In this work we discuss charged rotating black holes in AdS5×S5AdS_5 \times S^5 that degenerate to extremal black holes with zero entropy. These black holes have scaling properties between charge and angular momentum similar to those of Fermi surface operators in a subsector of N=4\mathcal{N}=4 SYM. We add a massless uncharged scalar to the five dimensional supergravity theory, such that it still forms a consistent truncation of the type IIB ten dimensional supergravity and analyze its quasinormal modes. Separating the equation of motion to a radial and angular part, we proceed to solve the radial equation using the asymptotic matching expansion method applied to a Heun equation with two nearby singularities. We use the continued fraction method for the angular Heun equation and obtain numerical results for the quasinormal modes. In the case of the supersymmetric black hole we present some analytic results for the decay rates of the scalar perturbations. The spectrum of quasinormal modes obtained is similar to that of a chiral 1+1 CFT, which is consistent with the conjectured field-theoretic dual. In addition, some of the modes can be found analytically.Comment: 41 pages, 1 figure, LaTeX; v2: typos corrected, references adde

    Optical conductivity of the nonsuperconducting cuprate La(8-x)Sr(x)Cu(8)O(20)

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    La(8-x)Sr(x)Cu(8)O(20) is a non-superconducting cuprate, which exhibits a doubling of the elementary cell along the c axis. Its optical conductivity sigma (omega) has been first measured here, down to 20 K, in two single crystals with x = 1.56 and x = 2.24. Along c, sigma (omega) shows, in both samples, bands due to strongly bound charges, thus confirming that the cell doubling is due to charge ordering. In the ab plane, in addition to the Drude term one observes an infrared peak at 0.1 eV and a midinfrared band at 0.7 eV. The 0.1 eV peak hardens considerably below 200 K, in correspondence of an anomalous increase in the sample dc resistivity, in agreement with its polaronic origin. This study allows one to establish relevant similarities and differences with respect to the spectrum of the ab plane of the superconducting cuprates.Comment: Revised version submitted to Phys. Rev. B, including the elimination of Fig. 1 and changes to Figs. 4 and

    Urban energy consumption and CO2 emissions in Beijing: current and future

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    This paper calculates the energy consumption and CO2 emissions of Beijing over 2005–2011 in light of the Beijing’s energy balance table and the carbon emission coefficients of IPCC. Furthermore, based on a series of energy conservation planning program issued in Beijing, the Long-range Energy Alternatives Planning System (LEAP)-BJ model is developed to study the energy consumption and CO2 emissions of Beijing’s six end-use sectors and the energy conversion sector over 2012–2030 under the BAU scenario and POL scenario. Some results are found in this research: (1) During 2005–2011, the energy consumption kept increasing, while the total CO2 emissions fluctuated obviously in 2008 and 2011. The energy structure and the industrial structure have been optimized to a certain extent. (2) If the policies are completely implemented, the POL scenario is projected to save 21.36 and 35.37 % of the total energy consumption and CO2 emissions than the BAU scenario during 2012 and 2030. (3) The POL scenario presents a more optimized energy structure compared with the BAU scenario, with the decrease of coal consumption and the increase of natural gas consumption. (4) The commerce and service sector and the energy conversion sector will become the largest contributor to energy consumption and CO2 emissions, respectively. The transport sector and the industrial sector are the two most potential sectors in energy savings and carbon reduction. In terms of subscenarios, the energy conservation in transport (TEC) is the most effective one. (5) The macroparameters, such as the GDP growth rate and the industrial structure, have great influence on the urban energy consumption and carbon emissions
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