3,183 research outputs found
Predictive Effects of Gender, SES, and Body Mass Index Scores on Student Achievement
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
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 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 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 -
4.5 detection of the kSZ 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
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 3.8-4.5 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 CDM cosmology, we directly constrain (statistical error
only) at redshift , where is the fraction of matter in
baryonic form and is the free electron fraction. This is the
tightest kSZ-derived constraint reported to date on these parameters. The
consistency between the 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 Mpc
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
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 ()
by the proposed Primordial Inflation Explorer (PIXIE). Although cosmic variance
reduces the effective signal-to-noise to , 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 , 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
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A highly scalable Met Office NERC Cloud model
Large Eddy Simulation is a critical modelling tool for scien- tists investigating atmospheric flows, turbulence and cloud microphysics. Within the UK, the principal LES model used by the atmospheric research community is the Met Office Large Eddy Model (LEM). The LEM was originally devel- oped in the late 1980s using computational techniques and assumptions of the time, which means that the it does not scale beyond 512 cores. In this paper we present the Met Office NERC Cloud model, MONC, which is a re-write of the existing LEM. We discuss the software engineering and architectural decisions made in order to develop a flexible, extensible model which the community can easily customise for their own needs. The scalability of MONC is evaluated, along with numerous additional customisations made to fur- ther improve performance at large core counts. The result of this work is a model which delivers to the community signifi- cant new scientific modelling capability that takes advantage of the current and future generation HPC machine
Google Search Mastery Basics
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
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
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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