817 research outputs found

    Elliptic CMB Sky

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    The ellipticity of the anisotropy spots of the Cosmic Microwave Background measured by the Wilkinson Microwave Anisotropy Probe (WMAP) has been studied. We find an average ellipticity of about 2, confirming with a far larger statistics similar results found first for the COBE-DMR CMB maps, and then for the BOOMERanG CMB maps. There are no preferred directions for the obliquity of the anisotropy spots. The average ellipticity is independent of temperature threshold and is present on scales both smaller and larger than the horizon at the last scattering. The measured ellipticity characteristics are consistent with being the effect of geodesics mixing occurring in an hyperbolic Universe, and can mark the emergence of CMB ellipticity as a new observable constant describing the Universe. There is no way of simulating this effect. Therefore we cannot exclude that the observed behavior of the measured ellipticity can result from a trivial topology in the popular flat Λ\Lambda-CDM model, or from a non-trivial topology.Comment: 10 pages, 5 figures, the version to appear in Mod.Phys.Lett.

    The Common Core Writing Standards: A Descriptive Study of Content and Alignment with A Sample of Former State Standards

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    Many students do not meet expected standards of writing performance, despite the need for writing competence in and out of school. As policy instruments, writing content standards have an impact on what is taught and how students perform. This study reports findings from an evaluation of the content of a sample of seven diverse states’ current writing standards compared to content of the Common Core State Standards for writing and language (CCSS-WL). Standards were evaluated for breadth of content coverage (range), how often content was referenced (frequency), the degree of emphasis placed on varied content elements (balance), and the degree of overlap between one set of standards and another (alignment). The study addressed two research questions: (1) What is the nature of the CCSS-WL and the sample states’ standards for writing with respect to content breadth, frequency, and balance? (2) To what degree do the states\u27 writing standards align with the CCSS-WL? Results indicated that CCSS-WL are succinct and balanced, with breadth of coverage in some aspects of writing but not others. The seven states’ standards represented varying degrees of breadth, frequency, and balance with few patterns across states. None of the states’ standards had strong alignment with CCSS-WL, indicating a potential mismatch between prior curricular materials and instructional methods developed with former standards as guides to help students meet grade-level writing expectations in the new CCSS

    WMAP confirming the ellipticity in BOOMERanG and COBE CMB maps

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    The recent study of BOOMERanG 150 GHz Cosmic Microwave Background (CMB) radiation maps have detected ellipticity of the temperature anisotropy spots independent on the temperature threshold. The effect has been found for spots up to several degrees in size, where the biases of the ellipticity estimator and of the noise are small. To check the effect, now we have studied, with the same algorithm and in the same sky region, the WMAP maps. We find ellipticity of the same average value also in WMAP maps, despite of the different sensitivity of the two experiments to low multipoles. Large spot elongations had been detected also for the COBE-DMR maps. If this effect is due to geodesic mixing and hence due to non precisely zero curvature of the hyperbolic Universe, it can be linked to the origin of WMAP low multipoles anomaly.Comment: More explanations and two references adde

    Is there a common origin for the WMAP low multipole and for the ellipticity in BOOMERanG CMB maps?

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    We have measured the ellipticity of several degree scale anisotropies in the BOOMERanG maps of the Cosmic Microwave Background (CMB) at 150 GHz. The average ellipticity is around 2.6-2.7. The biases of the estimator of the ellipticity and for the noise are small in this case. Large spot elongation had been detected also for COBE-DMR maps. If this effect is due to geodesic mixing, it would indicate a non precisely zero curvature of the Universe which is among the discussed reasons of the WMAP low multipole anomaly. Both effects are related to the diameter of the Universe: the geodesics mixing through hyperbolic geometry, low multipoles through boundary conditions.This common reason can also be related with the origin of the the cosmological constant: the modes of vacuum fluctuations conditioned by the boundary conditions lead to a value of the cosmological constant being in remarkable agreement with the supernovae observations.Comment: Added: two co-authors and a comment on the possible relation of the discussed CMB properties with the origin of the observed value of the cosmological constan

    Severe Hemoperitoneum after Patient Self-Induced Fecal Evacuation

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    An increasing incidence of rectal injuries following patient self-induced harmful acts, aimed to sexual or laxatives porpouses, is a fact reported in literature (El-Ashaal et al., 2008). We herein report a case of severe hemoperitoneum related to a middle and upper rectal third seromuscolar tear caused by a self-induced fecal evacuation by means of an arrow with a covered cork tip. An urgent intestinal diversion by means of a Hartmann's operation was performed. The clinical case is presented in relation to the literature debate, regarding the issue of primary repair or resection and anastomosis versus fecal diversion for penetrating rectal injuries (Fabian, 2002; Cleary et al., 2006; Office of the Surgeon General, 1943; Busic et al., 2002). In conclusion, the importance of avoiding an anastomotic breakdown in a patient undergoing a hemorrhagic shock is highlighted

    Deep Learning-based Traffic Prediction for Network Optimization

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    In recent years, researchers realized that the analysis of traffic datasets can reveal valuable information for the management of mobile and metro-core networks. That is getting more and more true with the increase in the use of social media and Internet applications on mobile devices. In this work, we focus on deep learning methods to make prediction of traffic matrices that allow us to proactively optimize the resource allocations of optical backbone networks. Recurrent Neural Networks (RNNs) are designed for sequence prediction problems and they achieved great results in the past years in tasks like speech recognition, handwriting recognition and prediction of time series data. We investigated a particular type of RNN, the Gated Recurrent Units (GRU), able to achieve great accuracy (<7.4 of mean absolute error). Then, we used the predictions to dynamically and proactively allocate the resources of an optical network. Comparing numerical results of static vs dynamic allocation based on predictions, we can estimate a saving of 66.3% of the available capacity in the network, managing unexpected traffic peaks

    The trispectrum of the Cosmic Microwave Background on sub-degree angular scales: an analysis of the BOOMERanG data

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    The trispectrum of the cosmic microwave background can be used to assess the level of non-Gaussianity on cosmological scales. It probes the fourth order moment, as a function of angular scale, of the probability distribution function of fluctuations and has been shown to be sensitive to primordial non-gaussianity, secondary anisotropies (such as the Ostriker-Vishniac effect) and systematic effects (such as astrophysical foregrounds). In this paper we develop a formalism for estimating the trispectrum from high resolution sky maps which incorporates the impact of finite sky coverage. This leads to a series of operations applied to the data set to minimize the effects of contamination due to the Gaussian component and correlations between estimates at different scales. To illustrate the effect of the estimation process, we apply our procedure to the BOOMERanG data set and show that it is consistent with Gaussianity. This work presents the first estimation of the CMB trispectrum on sub-degree scales.Comment: 14 pages, submitted to MNRA

    Improved Measurement of the Angular Power Spectrum of Temperature Anisotropy in the CMB from Two New Analyses of BOOMERANG Observations

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    We report the most complete analysis to date of observations of the Cosmic Microwave Background (CMB) obtained during the 1998 flight of BOOMERANG. We use two quite different methods to determine the angular power spectrum of the CMB in 20 bands centered at l = 50 to 1000, applying them to 50% more data than has previously been analyzed. The power spectra produced by the two methods are in good agreement with each other, and constitute the most sensitive measurements to date over the range 300 < l < 1000. The increased precision of the power spectrum yields more precise determinations of several cosmological parameters than previous analyses of BOOMERANG data. The results continue to support an inflationary paradigm for the origin of the universe, being well fit by a 13.5 Gyr old, flat universe composed of approximately 5% baryonic matter, 30% cold dark matter, and 65% dark energy, with a scale invariant initial density perturbations.Comment: 26 pages, 15 figures. Higher resolution figures available at http://cmb.phys.cwru.edu/boomerang/ Correction to numbers posted for MADCAP C_l's in Table 2. Correct numbers were used in figures and parameter extractio
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