3,183 research outputs found

    Predictive Effects of Gender, SES, and Body Mass Index Scores on Student Achievement

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    The purpose of this study was to determine the predictive effects of gender, SES, and BMI scores on academic achievement as measured by the ACT Aspire Exam for sixth- and eighth-grade students in rural, Delta schools in Arkansas. A quantitative, regression strategy was used to analyze the data. Predictor variables for each one of the hypotheses were gender, SES, and BMI scores. Criterion variables were ACT Aspire mathematics achievement and ACT Aspire reading achievement for Grades 6 and 8. Four Arkansas Delta schools participated in the study. The sample included 366 individual student scores from sixth-grade and 350 individual student scores from eighth grade. The results were analyzed by examining the combination of all predictor variables on the different criterion variables. Then, each predictor variable from each model was examined individually to determine how much it contributed to the overall prediction formula. The overall model significantly predicted mathematics and reading achievement for both Grade 6 and Grade 8. Results were consistent for each of the four hypotheses. Gender and SES significantly contributed to each of the prediction models and BMI did not

    The Kinematic Sunyaev-Zel'dovich Effect with Projected Fields II: prospects, challenges, and comparison with simulations

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    The kinematic Sunyaev-Zel'dovich (kSZ) signal is a powerful probe of the cosmic baryon distribution. The kSZ signal is proportional to the integrated free electron momentum rather than the electron pressure (which sources the thermal SZ signal). Since velocities should be unbiased on large scales, the kSZ signal is an unbiased tracer of the large-scale electron distribution, and thus can be used to detect the "missing baryon" that evade most observational techniques. While most current methods for kSZ extraction rely on the availability of very accurate redshifts, we revisit a method that allows measurements even in the absence of redshift information for individual objects. It involves cross-correlating the square of an appropriately filtered cosmic microwave background (CMB) temperature map with a projected density map constructed from a sample of large-scale structure tracers. We show that this method will achieve high signal-to-noise when applied to the next generation of high-resolution CMB experiments, provided that component separation is sufficiently effective at removing foreground contamination. Considering statistical errors only, we forecast that this estimator can yield S/NS/N \approx 3, 120 and over 150 for Planck, Advanced ACTPol, and hypothetical Stage-IV CMB experiments, respectively, in combination with a galaxy catalog from WISE, and about 20% larger S/NS/N for a galaxy catalog from the proposed SPHEREx experiment. This work serves as a companion paper to the first kSZ measurement with this method, where we used CMB temperature maps constructed from Planck and WMAP data, together with galaxies from the WISE survey, to obtain a 3.8 - 4.5σ\sigma detection of the kSZ2^2 amplitude.Comment: 14 pages, 10 figures. Comments welcom

    The Kinematic Sunyaev-Zel'dovich Effect with Projected Fields: A Novel Probe of the Baryon Distribution with Planck, WMAP, and WISE Data

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    The kinematic Sunyaev-Zel'dovich (kSZ) effect --- the Doppler boosting of cosmic microwave background (CMB) photons due to Compton-scattering off free electrons with non-zero bulk velocity --- probes the abundance and distribution of baryons in the Universe. All kSZ measurements to date have explicitly required spectroscopic redshifts. Here, we implement a novel estimator for the kSZ -- large-scale structure cross-correlation based on projected fields: it does not require redshift estimates for individual objects, allowing kSZ measurements from large-scale imaging surveys. We apply this estimator to cleaned CMB temperature maps constructed from Planck and Wilkinson Microwave Anisotropy Probe data and a galaxy sample from the Wide-field Infrared Survey Explorer (WISE). We measure the kSZ effect at 3.8-4.5σ\sigma significance, depending on the use of additional WISE galaxy bias constraints. We verify that our measurements are robust to possible dust emission from the WISE galaxies. Assuming the standard Λ\LambdaCDM cosmology, we directly constrain (fb/0.158)(ffree/1.0)=1.48±0.19( {f_{b}}/{0.158} ) ( {f_{\rm free}}/{1.0} ) = 1.48 \pm 0.19 (statistical error only) at redshift z0.4z \approx 0.4, where fbf_{b} is the fraction of matter in baryonic form and ffreef_{\rm free} is the free electron fraction. This is the tightest kSZ-derived constraint reported to date on these parameters. The consistency between the fbf_{b} value found here and the values inferred from analyses of the primordial CMB and Big Bang nucleosynthesis verifies that baryons approximately trace the dark matter distribution down to \simMpc scales. While our projected-field estimator is already competitive with other kSZ approaches when applied to current datasets (because we are able to use the full-sky WISE photometric survey), it will yield enormous signal-to-noise when applied to upcoming high-resolution, multi-frequency CMB surveys.Comment: 5 pages + references, 2 figures; v2: matches PRL accepted version, results unchange

    Taking the Universe's Temperature with Spectral Distortions of the Cosmic Microwave Background

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    The cosmic microwave background (CMB) energy spectrum is a near-perfect blackbody. The standard model of cosmology predicts small spectral distortions to this form, but no such distortion of the sky-averaged CMB spectrum has yet been measured. We calculate the largest expected distortion, which arises from the inverse Compton scattering of CMB photons off hot, free electrons, known as the thermal Sunyaev-Zel'dovich (tSZ) effect. We show that the predicted signal is roughly one order of magnitude below the current bound from the COBE-FIRAS experiment, but can be detected at enormous significance (1000σ\gtrsim 1000\sigma) by the proposed Primordial Inflation Explorer (PIXIE). Although cosmic variance reduces the effective signal-to-noise to 230σ230\sigma, this measurement will still yield a sub-percent constraint on the total thermal energy of electrons in the observable universe. Furthermore, we show that PIXIE can detect subtle relativistic effects in the sky-averaged tSZ signal at 30σ30\sigma, which directly probe moments of the optical depth-weighted intracluster medium electron temperature distribution. These effects break the degeneracy between the electron density and temperature in the mean tSZ signal, allowing a direct inference of the mean baryon density at low redshift. Future spectral distortion probes will thus determine the global thermodynamic properties of ionized gas in the universe with unprecedented precision. These measurements will impose a fundamental "integral constraint" on models of galaxy formation and the injection of feedback energy over cosmic time.Comment: 4.5 pages + references, 2 figures, comments welcome; v2: references updated; v3: matches PRL accepted versio

    Google Search Mastery Basics

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    Effective Internet search skills are essential with the continually increasing amount of information available on the Web. Extension personnel are required to find information to answer client questions and to conduct research on programs. Unfortunately, many lack the skills necessary to effectively navigate the Internet and locate needed information. Basic search skills are outlined as well as application to Extension

    Google Search Mastery Techniques

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    Knowledge is no longer something we possess, it\u27s now something we access. The Internet requires highly developed skills to access and interpret information. Relevant information is not the same as specific information. Previous articles in this series outlined basic search skills and operators that improve the relevancy of search results. Knowing how to formulate a specific query that will return a specific answer is critical in the 21st century. Expanding your understanding of Google Search and applying the search techniques in this article will serve you in your consumption and dissemination of content as an Extension professional

    Senior Recital: Joel Cruickshank, saxophone

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    This recital is presented in partial fulfillment of requirements for the degree Bachelor of Music in Performance. Mr. Cruickshank studies saxophone with Sam Skelton.https://digitalcommons.kennesaw.edu/musicprograms/1515/thumbnail.jp
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