85,714 research outputs found

    The transformation of hunger revisited: estimating available calories from the budgets of late nineteenth-century British households

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    Levels of nutrition among British worker's households in the late nineteenth century have been much debated. Trevon Logan (2006, 2009) estimated a very low average level of available calories. This paper re-examines the data and finds average levels of available calories much more in line with existing studies, more in line with what is known about energy requirements, and more in line with other aspects of the data. In sum, British households were likely to have been significantly better fed than Logan reports

    The significance of the integrated Sachs-Wolfe effect revisited

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    We revisit the state of the integrated Sachs-Wolfe (ISW) effect measurements in light of newly available data and address criticisms about the measurements which have recently been raised. We update the data set previously assembled by Giannantonio et al. to include new data releases for both the cosmic microwave background (CMB) and the large-scale structure (LSS) of the Universe. We find that our updated results are consistent with previous measurements. By fitting a single template amplitude, we now obtain a combined significance of the ISW detection at the 4.4 sigma level, which fluctuates by 0.4 sigma when alternative data cuts and analysis assumptions are considered. We also make new tests for systematic contaminations of the data, focusing in particular on the issues raised by Sawangwit et al. Amongst them, we address the rotation test, which aims at checking for possible systematics by correlating pairs of randomly rotated maps. We find results consistent with the expected data covariance, no evidence for enhanced correlation on any preferred axis of rotation, and therefore no indication of any additional systematic contamination. We publicly release the results, the covariance matrix, and the sky maps used to obtain them.Comment: 19 pages, 10 figures. MNRAS in pres

    Spectra of Modular and Small-World Matrices

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    We compute spectra of symmetric random matrices describing graphs with general modular structure and arbitrary inter- and intra-module degree distributions, subject only to the constraint of finite mean connectivities. We also evaluate spectra of a certain class of small-world matrices generated from random graphs by introducing short-cuts via additional random connectivity components. Both adjacency matrices and the associated graph Laplacians are investigated. For the Laplacians, we find Lifshitz type singular behaviour of the spectral density in a localised region of small λ|\lambda| values. In the case of modular networks, we can identify contributions local densities of state from individual modules. For small-world networks, we find that the introduction of short cuts can lead to the creation of satellite bands outside the central band of extended states, exhibiting only localised states in the band-gaps. Results for the ensemble in the thermodynamic limit are in excellent agreement with those obtained via a cavity approach for large finite single instances, and with direct diagonalisation results.Comment: 18 pages, 5 figure

    First impressions: introducing the 'Real Times' third sector case studies

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    ‘Real Times’ is the Third Sector Research Centre’s qualitative longitudinal study of third sector organisations, groups and activities. Over a three year period the study is following the fortunes, strategies, challenges and performance of a diverse set of fifteen ‘core’ case studies of third sector activity, and their relations with a number ‘complementary’ case studies. This report introduces the core case studies through summary sketches, and provides a descriptive account of the research up to the end of the first wave of fieldwork

    The imprints of the Galactic Bar on the Thick Disk with RAVE

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    We study the kinematics of a local sample of stars, located within a cylinder of 500 pc radius centered on the Sun, in the RAVE data set. We find clear asymmetries in the v R v∞ velocity distributions of thin and thick disk stars: there are more stars moving radially outward for low azimuthal velocities and more radially inward for high azimuthal velocities. Such asymmetries have been previously reported for the thin disk as being due to the Galactic bar, but this is the first time that the same type of structures are seen in the thick disk. Our findings imply that the velocities of thick-disk stars should no longer be described by Schwarzschilds, multivariate Gaussian or purely axisymmetric distributions. Furthermore, the nature of previously reported substructures in the thick disk needs to be revisited as these could be associated with dynamical resonances rather than to accretion events. It is clear that dynamical models of the Galaxy must fit the 3D velocity distributions of the disks, rather than the projected 1D, if we are to understand the Galaxy fully

    Report of the State Budget Crisis Task Force: Final Report

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    The objective of the State Budget Task Force is to inform the public of the character and gravity of the fiscal issues confronting the states and the consequences of deferring corrective actions. This report culminates three years of research, analysis, and debate. The authors encourage governments at all levels to consider its process recommendations and implement policies and programs that will lead to long-term structural adjustments

    Revisiting the WMAP - NVSS angular cross correlation. A skeptic's view

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    In the context of the study of the ISW, we revisit the angular cross correlation of WMAP CMB data with the NVSS radio survey. We compute 2-point cross functions between the two surveys in real and in Fourier space, paying particular attention on the dependence of results on the flux of NVSS radio sources, the angular scales where correlations arise and the comparison with theoretical expectations. We reproduce previous results that claim an excess of correlation in the angular correlation function (ACF), and we also find some (low significance) similarity between the CMB and radio galaxy data in the multipole range \el \in [10, 25]. However, the S/N in the ACFs increases with higher flux thresholds for NVSS sources, but drops a \sim 30 - 50% in separations of the order of a pixel size, suggesting some residual point source contribution. When restricting our analyses to multipoles \el \gt 60, we fail to find any evidence for cross correlation in the range \el \in [2,10], where according to the model predictions and our simulations \sim 50% of the S/N is supposed to arise. Also, the accumulated S/N for \el \lt 60 is below 1, far from the theoretical expectation of S/N5\sim 5. Part of this disagreement may be caused by an inaccurate modeling of the NVSS source population: as in previous works, we find a level of large scale (\el \lt 70) clustering in the NVSS catalog that seems incompatible with a high redshift population. This is unlikely to be caused by contaminants or systematics, since it is independent of flux threshold, and hence present for the brightest (>30σ\gt 30 \sigma) NVSS sources. Either our NVSS catalogs are not probing the high redshift, large scale gravitational potential wells, or there is a clear mismatch between the ISW component present in WMAP data and theoretical expectations.Comment: 16 pages, one extra figure (13 total), matches accepted version in A&
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