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Including homework and employability skills in class grades: An investigation of equitable grading outcomes in an urban high school
Historically, race and poverty have been contributing factors when considering gaps among students in their academic achievement. The purpose of this study was to determine how employability and homework scores within traditional points and percentages weighted grading models impact grades from an equity lens. This study analyzed 779 students’ semester math grades at an urban high school to see if students’ grades were inflated or deflated due to including homework and employability scores in the grade. Final grades which included homework and employability points were compared to each student’s overall summative assessment scores to determine grade inflation or deflation. The study then analyzed if including homework and employability points in the grade helped or hurt student’s grades based on race and socio-economic factors. In comparing grading results based on students\u27 socio-economic statuses, there were statistically significant differences (
Wrack enhancement of post-hurricane vegetation and geomorphological recovery in a coastal dune
Coastal ecosystems such as sand dunes, mangrove forests, and salt marshes provide natural storm protection for vulnerable shorelines. At the same time, storms erode and redistribute biological materials among coastal systems via wrack. Yet how such cross-ecosystem subsidies affect post-storm recovery is not well understood. Here, we report an experimental investigation into the effect of storm wrack on eco-geomorphological recovery of a coastal embryo dune in north-eastern Florida, USA, following hurricane Irma. We contrasted replicated 100-m2 wrack-removal and unmanipulated (control) plots, measuring vegetation and geomorphological responses over 21 months. Relative to controls, grass cover was reduced 4-fold where diverse storm wrack, including seagrass rhizomes, seaweed, and wood, was removed. Wrack removal was also associated with a reduction in mean elevation, which persisted until the end of the experiment when removal plots had a 14% lower mean elevation than control plots. These results suggest that subsides of wrack re-distributed from other ecosystem types (e.g. seagrasses, macroalgae, uplands): i) enhances the growth of certain dune-building grasses; and ii) boosts the geomorphological recovery of coastal dunes. Our study also indicates that the practice of post-storm beach cleaning to remove wrack–a practice widespread outside of protected areas–may undermine the resilience of coastal dunes and their services
A Demonstration of Spectral and Spatial Interferometry at THz Frequencies
A laboratory prototype spectral/spatial interferometer has been constructed
to demonstrate the feasibility of the double Fourier technique at Far Infrared
(FIR) wavelengths (0.15 - 1 THz). It is planned to use this demonstrator to
investigate and validate important design features and data processing methods
for future astronomical FIR interferometer instruments. In building this
prototype we have had to address several key technologies to provide an end-end
system demonstration of this double Fourier interferometer. We report on the
first results taken when viewing single slit and double slit sources at the
focus of a large collimator used to simulate real sources at infinity. The
performance of the prototype instrument for these specific field geometries is
analyzed to compare with the observed interferometric fringes and to
demonstrate image reconstruction capabilities.Comment: Accepted for publication in Applied Optic
Luminous Supernovae: Unveiling a Population Between Superluminous and Normal Core-collapse Supernovae
Stripped-envelope core-collapse supernovae can be divided into two broad
classes: the common Type Ib/c supernovae (SNe Ib/c), powered by the radioactive
decay of Ni, and the rare superluminous supernovae (SLSNe), most likely
powered by the spin-down of a magnetar central engine. Up to now, the
intermediate regime between these two populations has remained mostly
unexplored. Here, we present a comprehensive study of 40 \textit{luminous
supernovae} (LSNe), SNe with peak magnitudes of to mag, bound
by SLSNe on the bright end and by SNe Ib/c on the dim end. Spectroscopically,
LSNe appear to form a continuum between Type Ic SNe and SLSNe. Given their
intermediate nature, we model the light curves of all LSNe using a combined
magnetar plus radioactive decay model and find that they are indeed
intermediate, not only in terms of their peak luminosity and spectra, but also
in their rise times, power sources, and physical parameters. We sub-classify
LSNe into distinct groups that are either as fast-evolving as SNe Ib/c or as
slow-evolving as SLSNe, and appear to be either radioactively or magnetar
powered, respectively. Our findings indicate that LSNe are powered by either an
over-abundant production of Ni or by weak magnetar engines, and may
serve as the missing link between the two populations.Comment: 39 pages, 16 figures, submitted to Ap
Decoupling the World Wide Web From Linked Lists in I/O Automata
E-business must work. After years of structured research into information retrieval systems, we argue the emulation of checksums. We propose new stable technology, which we call ILIUM
The Dust in M31
We have analysed Herschel observations of M31, using the PPMAP procedure. The
resolution of PPMAP images is sufficient (31 pc on M31) that we can analyse
far-IR dust emission on the scale of Giant Molecular Clouds. By comparing PPMAP
estimates of the far-IR emission optical depth at 300 microns (tau_300), and
the near-IR extinction optical depth at 1.1 microns (tau_1.1) obtained from the
reddening of RGB stars, we show that the ratio R_OBS.tau = tau_1.1/tau_300
falls in the range 500 to 1500. Such low values are incompatible with many
commonly used theoretical dust models, which predict values of R_MODEL.kappa =
kappa_1.1/kappa_300 (where kappa is the dust opacity coefficient) in the range
2500 to 4000. That is, unless a large fraction, at least 60%, of the dust
emitting at 300 microns is in such compact sources that they are unlikely to
intercept the lines of sight to a distributed population like RGB stars. This
is not a new result: variants obtained using different observations and/or
different wavelengths have already been reported by other studies. We present
two analytic arguments for why it is unlikely that at least 60% of the emitting
dust is in sufficiently compact sources. Therefore it may be necessary to
explore the possibility that the discrepancy between observed values of
R_OBS.tau and theoretical values of R_MODEL.kappa is due to limitations in
existing dust models. PPMAP also allows us to derive optical-depth weighted
mean values for the emissivity index, beta = - dln(kappa_lambda)/dln(lambda),
and the dust temperature, T, denoted betabar and Tbar. We show that, in M31,
R_OBS.tau is anti-correlated with betabar according to R_OBS.tau =
2042(+/-24)-557(+/-10)betabar. If confirmed, this provides a challenging
constraint on the nature of interstellar dust in M31.Comment: 17 pages, 8 figures, 3 table
SN 2016iet: The Pulsational or Pair Instability Explosion of a Low Metallicity Massive CO Core Embedded in a Dense Hydrogen-Poor Circumstellar Medium
We present optical photometry and spectroscopy of SN 2016iet, an
unprecedented Type I supernova (SN) at with no obvious analog in the
existing literature. The peculiar light curve has two roughly equal brightness
peaks ( mag) separated by 100 days, and a subsequent slow decline
by 5 mag in 650 rest-frame days. The spectra are dominated by emission lines of
calcium and oxygen, with a width of only km s, superposed on a
strong blue continuum in the first year, and with a large ratio of at late times. There is no clear evidence
for hydrogen or helium associated with the SN at any phase. We model the light
curves with several potential energy sources: radioactive decay, central
engine, and circumstellar medium (CSM) interaction. Regardless of the model,
the inferred progenitor mass near the end of its life (i.e., CO core mass) is
M and up to M, placing the event in the
regime of pulsational pair instability supernovae (PPISNe) or pair instability
supernovae (PISNe). The models of CSM interaction provide the most consistent
explanation for the light curves and spectra, and require a CSM mass of
M ejected in the final decade before explosion. We further
find that SN 2016iet is located at an unusually large offset ( kpc) from
its low metallicity dwarf host galaxy ( Z, M), supporting the PPISN/PISN interpretation. In the final
spectrum, we detect narrow H emission at the SN location, likely due to
a dim underlying galaxy host or an H II region. Despite the overall consistency
of the SN and its unusual environment with PPISNe and PISNe, we find that the
inferred properties of SN\,2016iet challenge existing models of such events.Comment: 26 Pages, 17 Figures, Submitted to Ap
The Effects of Supplementing Wet Distillers Grains Mixed With Wheat Straw to Growing Steers
A growing study compared feeding wet distillers grains, dried distillers grains, and a mix of 66% wet distillers grains and 33% wheat straw as supplements to a forage-based diet. Steers were supplemented 0, 2, 4, or 6 lb distillers grains/head daily. Wet distillers grains and dried distillers grains produced higher final body weight and dry matter intake compared to the mix. Increasing levels of distillers grains increased performance in forage based diets and wet grains mixed with straw reduced forage intake
The Effects of Supplementing Wet Distillers Grains Mixed With Wheat Straw to Growing Steers
A growing study compared feeding wet distillers grains, dried distillers grains, and a mix of 66% wet distillers grains and 33% wheat straw as supplements to a forage-based diet. Steers were supplemented 0, 2, 4, or 6 lb distillers grains/head daily. Wet distillers grains and dried distillers grains produced higher final body weight and dry matter intake compared to the mix. Increasing levels of distillers grains increased performance in forage based diets and wet grains mixed with straw reduced forage intake
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