293 research outputs found

    Self-similar stable processes arising from high-density limits of occupation times of particle systems

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    We extend results on time-rescaled occupation time fluctuation limits of the (d,α,β)(d,\alpha, \beta)-branching particle system (0<α2,0<β1)(0<\alpha \leq 2, 0<\beta \leq 1) with Poisson initial condition. The earlier results in the homogeneous case (i.e., with Lebesgue initial intensity measure) were obtained for dimensions d>α/βd>\alpha / \beta only, since the particle system becomes locally extinct if dα/βd\le \alpha / \beta. In this paper we show that by introducing high density of the initial Poisson configuration, limits are obtained for all dimensions, and they coincide with the previous ones if d>α/βd>\alpha/\beta. We also give high-density limits for the systems with finite intensity measures (without high density no limits exist in this case due to extinction); the results are different and harder to obtain due to the non-invariance of the measure for the particle motion. In both cases, i.e., Lebesgue and finite intensity measures, for low dimensions (d<α(1+β)/βd<\alpha(1+\beta)/\beta and d<α(2+β)/(1+β)d<\alpha(2+\beta)/(1+\beta), respectively) the limits are determined by non-L\'evy self-similar stable processes. For the corresponding high dimensions the limits are qualitatively different: S(Rd){\cal S}'(R^d)-valued L\'evy processes in the Lebesgue case, stable processes constant in time on (0,)(0,\infty) in the finite measure case. For high dimensions, the laws of all limit processes are expressed in terms of Riesz potentials. If β=1\beta=1, the limits are Gaussian. Limits are also given for particle systems without branching, which yields in particular weighted fractional Brownian motions in low dimensions. The results are obtained in the setup of weak convergence of S'(R^d)$-valued processes.Comment: 28 page

    Analysis of the vector form factors fKπ+(Q2)f^+_{K\pi}(Q^2) and fKπ(Q2)f^-_{K\pi}(Q^2) with light-cone QCD sum rules

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    In this article, we calculate the vector form factors fKπ+(Q2)f^+_{K\pi}(Q^2) and fKπ(Q2)f^-_{K\pi}(Q^2) within the framework of the light-cone QCD sum rules approach. The numerical values of the fKπ+(Q2)f^+_{K\pi}(Q^2) are compatible with the existing theoretical calculations, the central value of the fKπ+(0)f^+_{K\pi}(0), fKπ+(0)=0.97f^+_{K\pi}(0)=0.97, is in excellent agreement with the values from the chiral perturbation theory and lattice QCD. The values of the fKπ(0)|f^-_{K\pi}(0)| are very large comparing with the theoretical calculations and experimental data, and can not give any reliable predictions. At large momentum transfers with Q2>5GeV2Q^2> 5GeV^2, the form factors fKπ+(Q2)f^+_{K\pi}(Q^2) and fKπ(Q2)|f^-_{K\pi}(Q^2)| can either take up the asymptotic behavior of 1Q2\frac{1}{Q^2} or decrease more quickly than 1Q2\frac{1}{Q^2}, more experimental data are needed to select the ideal sum rules.Comment: 22 pages, 16 figures, revised version, to appear in Eur. Phys. J.

    A Systematic Literature Review of Emotion Regulation Measurement in Individuals With Autism Spectrum Disorder

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    DOI: 10.1002/aur.1426Emotion regulation (ER) difficulties are a potential common factor underlying the presentation of multiple emotional and behavioral problems in individuals with Autism Spectrum Disorder (ASD). To provide an overview of how ER has been studied in individuals with ASD, we conducted a systematic review of the past 20 years of ER research in the ASD population, using established keywords from the most comprehensive ER literature review of the typically developing population to date. Out of an initial sampling of 305 studies, 32 were eligible for review. We examined the types of methods (self-report, informant report, naturalistic observation/ behavior coding, physiological, and open-ended) and the ER constructs based on Gross and Thompson’s modal model (situation selection, situation modification, attention deployment, cognitive change, and response modulation). Studies most often assessed ER using one type of method and from a unidimensional perspective. Across the 32 studies, we documented the types of measures used and found that 38% of studies used self-report, 44% included an informant report measure, 31% included at least one naturalistic observation/behavior coding measure, 13% included at least one physiological measure, and 13% included at least one open-ended measure. Only 25% of studies used more than one method of measurement. The findings of the current review provide the field with an in-depth analysis of various ER measures and how each measure taps into an ER framework. Future research can use this model to examine ER in a multicomponent way and through multiple methods.Spectrum of Hope Autism Foundation, Canadian Institutes of Health Research, NeuroDevNet, Sinneave Family Foundation, CASDA, Autism Speaks Canada, Health Canad

    The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment

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    The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since July 2014. This paper describes the second data release from this phase, and the fourteenth from SDSS overall (making this, Data Release Fourteen or DR14). This release makes public data taken by SDSS-IV in its first two years of operation (July 2014-2016). Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey (eBOSS); the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data driven machine learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS website (www.sdss.org) has been updated for this release, and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020, and will be followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14 happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov 2017 (this is the "post-print" and "post-proofs" version; minor corrections only from v1, and most of errors found in proofs corrected

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Optical Constants of Ices Important to Planetary Science From Laboratory Reflectance Spectroscopy

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    Laboratory-derived optical constants are essential for identifying ices and measuring their relative abundances on Solar System objects. Almost all optical constants of ices important to planetary science come from experiments with transmission geometries. Here, we describe our new experimental setup and the modification of an iterative algorithm in the literature to measure the optical constants of ices from experiments with reflectance geometries. We apply our techniques to CH4 ice and H2O ice samples and find good agreement between our values and those in the literature, except for one CH4 band in the literature that likely suffers from saturation. The work we present here demonstrates that labs with reflectance geometries can generate optical constants essential for the proper analysis of near- and mid-infrared spectra of outer Solar System objects such as those obtained with the James Webb Space Telescope

    Optical Constants of Ices Important to Planetary Science From Laboratory Reflectance Spectroscopy

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    Laboratory-derived optical constants are essential for identifying ices and measuring their relative abundances on Solar System objects. Almost all optical constants of ices important to planetary science come from experiments with transmission geometries. Here, we describe our new experimental setup and the modification of an iterative algorithm in the literature to measure the optical constants of ices from experiments with reflectance geometries. We apply our techniques to CH4 ice and H2O ice samples and find good agreement between our values and those in the literature, except for one CH4 band in the literature that likely suffers from saturation. The work we present here demonstrates that labs with reflectance geometries can generate optical constants essential for the proper analysis of near- and mid-infrared spectra of outer Solar System objects such as those obtained with the James Webb Space Telescope

    The Magnitude of Global Marine Species Diversity

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    Background: The question of how many marine species exist is important because it provides a metric for how much we do and do not know about life in the oceans. We have compiled the first register of the marine species of the world and used this baseline to estimate how many more species, partitioned among all major eukaryotic groups, may be discovered. Results: There are ∼226,000 eukaryotic marine species described. More species were described in the past decade (∼20,000) than in any previous one. The number of authors describing new species has been increasing at a faster rate than the number of new species described in the past six decades. We report that there are ∼170,000 synonyms, that 58,000–72,000 species are collected but not yet described, and that 482,000–741,000 more species have yet to be sampled. Molecular methods may add tens of thousands of cryptic species. Thus, there may be 0.7–1.0 million marine species. Past rates of description of new species indicate there may be 0.5 ± 0.2 million marine species. On average 37% (median 31%) of species in over 100 recent field studies around the world might be new to science. Conclusions: Currently, between one-third and two-thirds of marine species may be undescribed, and previous estimates of there being well over one million marine species appear highly unlikely. More species than ever before are being described annually by an increasing number of authors. If the current trend continues, most species will be discovered this century

    Measurement of the tau lepton lifetime

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    Limit on Bs0B^0_s oscillation using a jet charge method

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    A lower limit is set on the B_{s}^{0} meson oscillation parameter \Delta m_{s} using data collected from 1991 to 1994 by the ALEPH detector. Events with a high transverse momentum lepton and a reconstructed secondary vertex are used. The high transverse momentum leptons are produced mainly by b hadron decays, and the sign of the lepton indicates the particle/antiparticle final state in decays of neutral B mesons. The initial state is determined by a jet charge technique using both sides of the event. A maximum likelihood method is used to set a lower limit of \, \Delta m_{s}. The 95\% confidence level lower limit on \Delta m_s ranges between 5.2 and 6.5(\hbar/c^{2})~ps^{-1} when the fraction of b quarks from Z^0 decays that form B_{s}^{0} mesons is varied from 8\% to 16\%. Assuming that the B_{s}^{0} fraction is 12\%, the lower limit would be \Delta m_{s} 6.1(\hbar/c^{2})~ps^{-1} at 95\% confidence level. For x_s = \Delta m_s \, \tau_{B_s}, this limit also gives x_s 8.8 using the B_{s}^{0} lifetime of \tau_{B_s} = 1.55 \pm 0.11~ps and shifting the central value of \tau_{B_s} down by 1\sigma
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