12,918 research outputs found

    Resistance in a \u27Culture of Permission:\u27 Sociological Readings of the Correspondence with Persian Authorities in Ezra 1-7

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    The first six chapters of the book of Ezra center around an alleged correspondence between the Persian Emporer\u27s court and the local authorities of Palestine under Persian rule. Without question, these letters were crucial to the editors of Ezra-Nehemiah. But why? What does the reproduction of this alleged official correspondence mean to the final editors of Ezra-Nehemiah

    An improved estimator for non-Gaussianity in cosmic microwave background observations

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    An improved estimator for the amplitude fnl of local-type non-Gaussianity from the cosmic microwave background (CMB) bispectrum is discussed. The standard estimator is constructed to be optimal in the zero-signal (i.e., Gaussian) limit. When applied to CMB maps which have a detectable level of non-Gaussianity the standard estimator is no longer optimal, possibly limiting the sensitivity of future observations to a non-Gaussian signal. Previous studies have proposed an improved estimator by using a realization-dependent normalization. Under the approximations of a flat sky and a vanishingly thin last-scattering surface, these studies showed that the variance of this improved estimator can be significantly smaller than the variance of the standard estimator when applied to non-Gaussian CMB maps. Here this technique is generalized to the full sky and to include the full radiation transfer function, yielding expressions for the improved estimator that can be directly applied to CMB maps. The ability of this estimator to reduce the variance as compared to the standard estimator in the face of a significant non-Gaussian signal is re-assessed using the full CMB transfer function. As a result of the late time integrated Sachs-Wolfe effect, the performance of the improved estimator is degraded. If CMB maps are first cleaned of the late-time ISW effect using a tracer of foreground structure, such as a galaxy survey or a measurement of CMB weak lensing, the new estimator does remove a majority of the excess variance, allowing a higher significance detection of fnl.Comment: 21 pages, 7 figure

    Baryons still trace dark matter: probing CMB lensing maps for hidden isocurvature

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    Compensated isocurvature perturbations (CIPs) are primordial fluctuations that balance baryon and dark-matter isocurvature to leave the total matter density unperturbed. The effects of CIPs on the cosmic microwave background (CMB) anisotropies are similar to those produced by weak lensing of the CMB: smoothing of the power spectrum, and generation of non-Gaussian features. Previous work considered the CIP effects on the CMB power-spectrum but neglected to include the CIP effects on estimates of the lensing potential power spectrum (though its contribution to the non-Gaussian, connected, part of the CMB trispectrum). Here, the CIP contribution to the standard estimator for the lensing potential power-spectrum is derived, and along with the CIP contributions to the CMB power-spectrum, Planck data is used to place limits on the root-mean-square CIP fluctuations on CMB scales, Δrms2(RCMB)\Delta_{\rm rms}^2(R_{\rm CMB}). The resulting constraint of Δrms2(RCMB)<4.3×10−3\Delta_{\rm rms}^2(R_{\rm CMB}) < 4.3 \times 10^{-3} using this new technique improves on past work by a factor of ∼3\sim 3. We find that for Planck data our constraints almost reach the sensitivity of the optimal CIP estimator. The method presented here is currently the most sensitive probe of the amplitude of a scale-invariant CIP power spectrum placing an upper limit of ACIP<0.017A_{\rm CIP}< 0.017 at 95% CL. Future measurements of the large-scale CMB lensing potential power spectrum could probe CIP amplitudes as low as Δrms2(RCMB)=8×10−5\Delta_{\rm rms}^2(R_{\rm CMB}) = 8 \times 10^{-5} (ACIP=3.2×10−4A_{\rm CIP} = 3.2 \times 10^{-4}).Comment: 24 pages, 9 figures; comments welcome; v2 references correcte

    mSpace Mobile: Exploring Support for Mobile Tasks

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    In the following paper we compare two Web application interfaces, mSpace Mobile and Google Local in supporting location discovery tasks on mobile devices while stationary and while on the move. While mSpace Mobile performed well in both stationary and mobile conditions, performance in Google Local dropped significantly. We postulate that mSpace Mobile performed so well because it breaks the paradigm of the page for delivering Web content, thereby enabling new and more powerful interfaces to be used to support mobility

    mSpace: improving information access to multimedia domains with multimodal exploratory search

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    Overview of mSpace interaction approach for presenting exploratory search particularly in the audio domain by using slices, preview cues, and user-determined organization of information from high-dimensional space

    A Comparison of the Effects of Heat Stress on Milk and Component Yields and Somatic Cell Count in Holstein and Jersey Cows

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    Objective 1 was to investigate effects of heat stress and breed on milk and component yield for Holstein and Jersey cows on the same farm. Objective 2 was to determine the effects of breed on udder health as measured by somatic cell count (SCC) during times of heat stress. Data were collected from DHIA records of 142 Jersey cows and 586 Holstein cows from the University herd at Mississippi State University. During heat stress Jersey milk yield and 4% fat corrected milk (FCM) increased (P\u3c0.01). Holstein milk yield and FCM decreased during heat stress (P\u3c0.01). Heat stress affected somatic cell count (SCC) although effects varied by intensity of heat stress. Breed did not have an affect on SCC. Milk fat and protein percentages declined for both breeds in heat stress conditions. Milk fat but not milk protein of Jersey cows increased as stress increased from mild to severe
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