1,308 research outputs found
Findings From Surveys on Adventism, Politics and Social Issues
AHSRA Presentation Proposal
Abstract: The relationships between Adventism and the social political world has implications for the mission of the church and its involvement in the social issues of our time. Researches present an analysis of research conducted over several decades which explore the relationship of Adventism, politics and social issues
Non-parametric analysis of the rest-frame UV sizes and morphological disturbance amongst L* galaxies at 4<z<8
We present the results of a study investigating the sizes and morphologies of
redshift 4 < z < 8 galaxies in the CANDELS GOODS-S, HUDF and HUDF parallel
fields. Based on non-parametric measurements and incorporating a careful
treatment of measurement biases, we quantify the typical size of galaxies at
each redshift as the peak of the log-normal size distribution, rather than the
arithmetic mean size. Parameterizing the evolution of galaxy half-light radius
as , we find at bright
UV-luminosities () and at faint
luminosities (). Furthermore, simulations based on
artificially redshifting our z~4 galaxy sample show that we cannot reject the
null hypothesis of no size evolution. We show that this result is caused by a
combination of the size-dependent completeness of high-redshift galaxy samples
and the underestimation of the sizes of the largest galaxies at a given epoch.
To explore the evolution of galaxy morphology we first compare asymmetry
measurements to those from a large sample of simulated single S\'ersic
profiles, in order to robustly categorise galaxies as either `smooth' or
`disturbed'. Comparing the disturbed fraction amongst bright () galaxies at each redshift to that obtained by artificially redshifting
our z~4 galaxy sample, while carefully matching the size and UV-luminosity
distributions, we find no clear evidence for evolution in galaxy morphology
over the redshift interval 4 < z < 8. Therefore, based on our results, a bright
() galaxy at z~6 is no more likely to be measured as
`disturbed' than a comparable galaxy at z~4, given the current observational
constraints.Comment: 29 pages, 25 figures, 4 tables, published in MNRA
New Constraints on Cosmic Reionization from the 2012 Hubble Ultra Deep Field Campaign
Understanding cosmic reionization requires the identification and
characterization of early sources of hydrogen-ionizing photons. The 2012 Hubble
Ultra Deep Field (UDF12) campaign has acquired the deepest infrared images with
the Wide Field Camera 3 aboard Hubble Space Telescope and, for the first time,
systematically explored the galaxy population deep into the era when cosmic
microwave background (CMB) data indicates reionization was underway. The UDF12
campaign thus provides the best constraints to date on the abundance,
luminosity distribution, and spectral properties of early star-forming
galaxies. We synthesize the new UDF12 results with the most recent constraints
from CMB observations to infer redshift-dependent ultraviolet (UV) luminosity
densities, reionization histories, and electron scattering optical depth
evolution consistent with the available data. Under reasonable assumptions
about the escape fraction of hydrogen ionizing photons and the intergalactic
medium clumping factor, we find that to fully reionize the universe by redshift
z~6 the population of star-forming galaxies at redshifts z~7-9 likely must
extend in luminosity below the UDF12 limits to absolute UV magnitudes of
M_UV\sim -13 or fainter. Moreover, low levels of star formation extending to
redshifts z~15-25, as suggested by the normal UV colors of z\simeq7-8 galaxies
and the smooth decline in abundance with redshift observed by UDF12 to
z\simeq10, are additionally likely required to reproduce the optical depth to
electron scattering inferred from CMB observations.Comment: Version accepted by ApJ (originally submitted Jan 5, 2013). The UDF12
website can be found at http://udf12.arizona.ed
Multihospital Outbreak of Clostridium difficile Infection, Cleveland, Ohio, USA
To determine whether a multihospital Clostridium difficile outbreak was associated with epidemic strains and whether use of particular fluoroquinolones was associated with increased infection rates, we cultured feces from C. difficile–infected patients. Use of fluoroquionolones with enhanced antianaerobic activity was not associated with increased infection rates
10 simple rules to create a serious game, illustrated with examples from structural biology
Serious scientific games are games whose purpose is not only fun. In the
field of science, the serious goals include crucial activities for scientists:
outreach, teaching and research. The number of serious games is increasing
rapidly, in particular citizen science games, games that allow people to
produce and/or analyze scientific data. Interestingly, it is possible to build
a set of rules providing a guideline to create or improve serious games. We
present arguments gathered from our own experience ( Phylo , DocMolecules ,
HiRE-RNA contest and Pangu) as well as examples from the growing literature on
scientific serious games
The scattering of muons in low Z materials
This paper presents the measurement of the scattering of 172 MeV/c muons in
assorted materials, including liquid hydrogen, motivated by the need to
understand ionisation cooling for muon acceleration.
Data are compared with predictions from the Geant 4 simulation code and this
simulation is used to deconvolute detector effects. The scattering
distributions obtained are compared with the Moliere theory of multiple
scattering and, in the case of liquid hydrogen, with ELMS. With the exception
of ELMS, none of the models are found to provide a good description of the
data. The results suggest that ionisation cooling will work better than would
be predicted by Geant 4.7.0p01.Comment: pdfeTeX V 3.141592-1.21a-2.2, 30 pages with 22 figure
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