66 research outputs found

    Perceptions of Electoral Fairness and Voter Turnout

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    Previous research has established a link between turnout and the extent to which voters are faced with a “meaningful” partisan choice in elections; this study extends the logic of this argument to perceptions of the “meaningfulness” of electoral conduct. It hypothesizes that perceptions of electoral integrity are positively related to turnout. The empirical analysis to test this hypothesis is based on aggregate-level data from 31 countries, combined with survey results from Module 1 of the Comparative Study of Electoral Systems survey project, which includes new and established democracies. Multilevel modeling is employed to control for a variety of individual- and election-level variables that have been found in previous research to influence turnout. The results of the analysis show that perceptions of electoral integrity are indeed positively associated with propensity to vote. </jats:p

    Preliminary results for RR Lyrae stars and Classical Cepheids from the Vista Magellanic Cloud (VMC) Survey

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    The Vista Magellanic Cloud (VMC, PI M.R. Cioni) survey is collecting KSK_S-band time series photometry of the system formed by the two Magellanic Clouds (MC) and the "bridge" that connects them. These data are used to build KSK_S-band light curves of the MC RR Lyrae stars and Classical Cepheids and determine absolute distances and the 3D geometry of the whole system using the KK-band period luminosity (PLKSPLK_S), the period - luminosity - color (PLCPLC) and the Wesenhiet relations applicable to these types of variables. As an example of the survey potential we present results from the VMC observations of two fields centered respectively on the South Ecliptic Pole and the 30 Doradus star forming region of the Large Magellanic Cloud. The VMC KSK_S-band light curves of the RR Lyrae stars in these two regions have very good photometric quality with typical errors for the individual data points in the range of ∌\sim 0.02 to 0.05 mag. The Cepheids have excellent light curves (typical errors of ∌\sim 0.01 mag). The average KSK_S magnitudes derived for both types of variables were used to derive PLKSPLK_S relations that are in general good agreement within the errors with the literature data, and show a smaller scatter than previous studies.Comment: 7 pages, 6 figure. Accepted for publication in Astrophysics and Space Science. Following a presentation at the conference "The Fundamental Cosmic Distance Scale: State of the Art and the Gaia Perspective", Naples, May 201

    Upgraded photon calorimeter with integrating readout for Hall A Compton Polarimeter at Jefferson Lab

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    The photon arm of the Compton polarimeter in Hall A of Jefferson Lab has been upgraded to allow for electron beam polarization measurements with better than 1% accuracy. The data acquisition system (DAQ) now includes an integrating mode, which eliminates several systematic uncertainties inherent in the original counting-DAQ setup. The photon calorimeter has been replaced with a Ce-doped GSO crystal, which has a bright output and fast response, and works well for measurements using the new integrating method at electron beam energies from 1 to 6 GeV.Comment: 16 pages, 15 figure

    The Large Scale Structure in the Universe: From Power-Laws to Acoustic Peaks

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    The most popular tools for analysing the large scale distribution of galaxies are second-order spatial statistics such as the two-point correlation function or its Fourier transform, the power spectrum. In this review, we explain how our knowledge of cosmic structures, encapsulated by these statistical descriptors, has evolved since their first use when applied on the early galaxy catalogues to the present generation of wide and deep redshift surveys, incorporating the most challenging discovery in the study of the galaxy distribution: the detection of Baryon Acoustic Oscillations.Comment: 20 pages, 12 figures, to appear in "Data Analysis in Cosmology", Lecture Notes in Physics, 2008, eds. V. J. Martinez, E. Saar, E. Martinez-Gonzalez, and M.J. Pons-Borderia, Springer-Verla

    Early above- and below-ground responses of subboreal conifer seedlings to various levels of deciduous canopy removal

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    We examined the growth of understory conifers, following partial or complete deciduous canopy removal, in a field study established in two regions in Canada. In central British Columbia, we studied the responses of three species (Pseudotsuga menziesii var. glauca (Beissn.) Franco, Picea glauca (Moench) Voss x Picea engelmannii Parry ex Engelm., and Abies lasiocarpa (Hook.) Nutt.), and in northwestern Quebec, we studied one species (Abies balsamea (L.) Mill.). Stem and root diameter and height growth were measured 5 years before and 3 years after harvesting. Both root and stem diameter growth increased sharply following release but seedlings showed greater root growth, suggesting that in the short term, improvement in soil resource capture and transport, and presumably stability, may be more important than an increase in stem diameter and height growth. Response was strongly size dependent, which appears to reflect greater demand for soil resources as well as higher light levels and greater tree vigour before release for taller individuals. Growth ratios could not explain the faster response generally attributed to true fir species or the unusual swift response of spruces. Good prerelease vigour of spruces, presumably favoured by deciduous canopies, could explain their rapid response to release

    Cosmology with clusters of galaxies

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    In this Chapter I review the role that galaxy clusters play as tools to constrain cosmological parameters. I will concentrate mostly on the application of the mass function of galaxy clusters, while other methods, such as that based on the baryon fraction, are covered by other Chapters of the book. Since most of the cosmological applications of galaxy clusters rely on precise measurements of their masses, a substantial part of my Lectures concentrates on the different methods that have been applied so far to weight galaxy clusters. I provide in Section 2 a short introduction to the basics of cosmic structure formation. In Section 3 I describe the Press--Schechter (PS) formalism to derive the cosmological mass function, then discussing extensions of the PS approach and the most recent calibrations from N--body simulations. In Section 4 I review the methods to build samples of galaxy clusters at different wavelengths. Section 5 is devoted to the discussion of different methods to derive cluster masses. In Section 6 I describe the cosmological constraints, which have been obtained so far by tracing the cluster mass function with a variety of methods. Finally, I describe in Section 7 the future perspectives for cosmology with galaxy clusters and the challenges for clusters to keep playing an important role in the era of precision cosmology.Comment: 49 pages, 19 figures, Lectures for 2005 Guillermo Haro Summer School on Clusters, to appear in "Lecture notes in Physics" (Springer

    Para-infectious brain injury in COVID-19 persists at follow-up despite attenuated cytokine and autoantibody responses

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    To understand neurological complications of COVID-19 better both acutely and for recovery, we measured markers of brain injury, inflammatory mediators, and autoantibodies in 203 hospitalised participants; 111 with acute sera (1–11 days post-admission) and 92 convalescent sera (56 with COVID-19-associated neurological diagnoses). Here we show that compared to 60 uninfected controls, tTau, GFAP, NfL, and UCH-L1 are increased with COVID-19 infection at acute timepoints and NfL and GFAP are significantly higher in participants with neurological complications. Inflammatory mediators (IL-6, IL-12p40, HGF, M-CSF, CCL2, and IL-1RA) are associated with both altered consciousness and markers of brain injury. Autoantibodies are more common in COVID-19 than controls and some (including against MYL7, UCH-L1, and GRIN3B) are more frequent with altered consciousness. Additionally, convalescent participants with neurological complications show elevated GFAP and NfL, unrelated to attenuated systemic inflammatory mediators and to autoantibody responses. Overall, neurological complications of COVID-19 are associated with evidence of neuroglial injury in both acute and late disease and these correlate with dysregulated innate and adaptive immune responses acutely

    A survey of rich clusters of galaxies

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    Available from British Library Document Supply Centre- DSC:D171979 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo
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