296 research outputs found
Attitudes of Whitehorse Canada Grade 12 Students towards Harm Reduction as An Intervention Strategy for Crack/Heroin Dependency
This study investigated the association between the psychological variables of conservatism, religiosity, sensation seeking, and health locus of control (HLOC) with Whitehorse Grade 12 studentsā attitudes toward harm reduction as an intervention. A total of 138 high school students in Whitehorse Yukon, Canada voluntarily filled out a questionnaire designed to meet the objectives of the study. GLM multivariate analysis of variance (MANOVA) showed that female participants reported higher levels of conservatism and religiosity than their male counterparts. Multiple regression analysis was conducted to test the impact of the psychological variables of conservatism, religiosity, sensation seeking, and HLOC on attitudes toward harm reduction as an intervention. The results indicated that only the variable of powerful others HLOC was significantly and negatively associated with the participantsā attitude toward harm reduction as an intervention. The findings were discussed in terms of the role that external HLOC, in particular, the belief that oneās life is controlled by powerful others, may play in the overall level of support for harm reduction as an intervention strategy for drug addiction
Electronic Perception Technology Applications in Food Service
Electronic Perception Technology (EPT) enables automated equipment to gain artificial sight commonly referred to as machine-visionā by employing specialty software and embedded sensors to create a āVisual input field that can be used as a front-end application for transactional behavior. The authors review this new technology and present feasible future applications to the food service industry in enhancing guest services while providing a competitive advantage
Forward and Inverse Modeling of the Emission and Transmission Spectrum of GJ 436b: Investigating Metal Enrichment, Tidal Heating, and Clouds
The Neptune-mass GJ 436b is one of the most-studied transiting exoplanets
with repeated measurements of both its thermal emission and transmission
spectra. We build on previous studies to answer outstanding questions about
this planet, including its potentially high metallicity and tidal heating of
its interior. We present new observations of GJ 436b's thermal emission at 3.6
and 4.5 micron, which reduce uncertainties in estimates of GJ 436b's flux at
those wavelengths and demonstrate consistency between Spitzer observations
spanning more than 7 years. We analyze the Spitzer thermal emission photometry
and Hubble WFC3 transmission spectrum in tandem. We use a powerful dual-pronged
modeling approach, comparing these data to both self-consistent and retrieval
models. We vary the metallicity, intrinsic luminosity from tidal heating,
disequilibrium chemistry, and heat redistribution. We also study the effect of
clouds and photochemical hazes on the spectra, but do not find strong evidence
for either. The self-consistent and retrieval modeling combine to suggest that
GJ 436b has a high atmospheric metallicity, with best fits at or above several
hundred times solar metallicity, tidal heating warming its interior with
best-fit intrinsic effective effective temperatures around 300--350 K, and
disequilibrium chemistry. High metal-enrichments (>600x solar) can only occur
from the accretion of rocky, rather than icy, material. Assuming Tint~300--350
K, we find that Q'~2x10^5--10^6, larger than Neptune's Q', and implying a long
tidal circularization timescale for the planet's orbit. We suggest that
Neptune-mass planets may be a more diverse class than previously imagined, with
metal-enhancements potentially spanning several orders of magnitude, to perhaps
over 1000x solar metallicity. High fidelity observations with instruments like
JWST will be critical for characterizing this diversity.Comment: 15 pages, 18 figures. Revised for publication in Ap
A Survey of Alkali Line Absorption in Exoplanetary Atmospheres
We obtained over 90 hours of spectroscopic observations of four exoplanetary
systems with the Hobby-Eberly Telescope (HET). Observations were taken in
transit and out of transit, and we analyzed the differenced spectra---i.e., the
transmission spectra---to inspect it for absorption at the wavelengths of the
neutral sodium (\ion{Na}{1}) doublet at and neutral
potassium (\ion{K}{1}) at . We used the transmission spectrum at
\ion{Ca}{1} ---which shows strong stellar absorption but is not an
alkali metal resonance line that we expect to show significant absorption in
these atmospheres---as a control line to examine our measurements for
systematic errors. We use an empirical Monte Carlo method to quantity these
systematic errors. In a reanalysis of the same dataset using a reduction and
analysis pipeline that was derived independently, we confirm the previously
seen \ion{Na}{1} absorption in HD 189733b at a level of
(the average value over a 12 \AA{} integration
band to be consistent with previous authors). Additionally, we tentatively
confirm the \ion{Na}{1} absorption seen in HD 209458b (independently by
multiple authors) at a level of , though the
interpretation is less clear. Furthermore, we find \ion{Na}{1} absorption of
at in HD 149026b; features apparent in
the transmission spectrum are consistent with real absorption and indicate this
may be a good target for future observations to confirm. No other results
(\ion{Na}{1} in HD 147506b and \ion{Ca}{1} and \ion{K}{1} in all four targets)
are significant to , although we observe some features that we
argue are primarily artifacts.Comment: 38 total pages (preprint format), 9 color figures, 4 tables, accepted
for publication in Ap
Ground- and Space-based Detection of the Thermal Emission Spectrum of the Transiting Hot Jupiter KELT-2Ab
We describe the detection of water vapor in the atmosphere of the transiting
hot Jupiter KELT-2Ab by treating the star-planet system as a spectroscopic
binary with high-resolution, ground-based spectroscopy. We resolve the signal
of the planet's motion with deep combined flux observations of the star and the
planet. In total, six epochs of Keck NIRSPEC -band observations were
obtained, and the full data set was subjected to a cross correlation analysis
with a grid of self-consistent atmospheric models. We measure a radial
projection of the Keplerian velocity, , of 148 7 km s,
consistent with transit measurements, and detect water vapor at 3.8. We
combine NIRSPEC -band data with IRAC secondary eclipse data to
further probe the metallicity and carbon-to-oxygen ratio of KELT-2Ab's
atmosphere. While the NIRSPEC analysis provides few extra constraints on the
data, it does provide roughly the same constraints on metallicity and
carbon-to-oxygen ratio. This bodes well for future investigations of the
atmospheres of non-transiting hot Jupiters.Comment: accepted to A
The Confounding Effects of Particle Size and Substrate Bulk Density on \u3cem\u3ePhanerochaete chrysosporium\u3c/em\u3e Pretreatment on \u3cem\u3ePanicum virgatum\u3c/em\u3e
Phanerochaete chrysosporium treatment is less effective as a biological pretreatment on feedstock with larger particle sizes. We hypothesized that the improved effectiveness of the pretreatment when smaller particle sizes are used may be due to the inherently higher bulk density with smaller particle sizes. The effects of substrate bulk density and particle size on the efficacy of P. chrysosporium pretreatment of switchgrass (Panicum virgatum) was tested experimentally. Phanerochaete chrysosporium was grown on senesced switchgrass (2 different particle sizes) with various bulk densities. In all treatments, the fungal-pretreated samples released more glucose during enzymatic saccharification than the control sample. Substrate bulk density was a statistically significant factor in explaining the variation in the amount of glucose released per gram of substrate used. However, the particle size was not found to be a significant factor. On-farm switchgrass pretreatment may not require particle size reduction if the switchgrass is supplied in high-density bales
Characterization and validation of an intra-fraction motion management system for masked-based radiosurgery
NIMBUS: The Near-Infrared Multi-Band Ultraprecise Spectroimager for SOFIA
We present a new and innovative near-infrared multi-band ultraprecise
spectroimager (NIMBUS) for SOFIA. This design is capable of characterizing a
large sample of extrasolar planet atmospheres by measuring elemental and
molecular abundances during primary transit and occultation. This wide-field
spectroimager would also provide new insights into Trans-Neptunian Objects
(TNO), Solar System occultations, brown dwarf atmospheres, carbon chemistry in
globular clusters, chemical gradients in nearby galaxies, and galaxy
photometric redshifts. NIMBUS would be the premier ultraprecise spectroimager
by taking advantage of the SOFIA observatory and state of the art infrared
technologies.
This optical design splits the beam into eight separate spectral bandpasses,
centered around key molecular bands from 1 to 4 microns. Each spectral channel
has a wide field of view for simultaneous observations of a reference star that
can decorrelate time-variable atmospheric and optical assembly effects,
allowing the instrument to achieve ultraprecise calibration for imaging and
photometry for a wide variety of astrophysical sources. NIMBUS produces the
same data products as a low-resolution integral field spectrograph over a large
spectral bandpass, but this design obviates many of the problems that preclude
high-precision measurements with traditional slit and integral field
spectrographs. This instrument concept is currently not funded for development.Comment: 14 pages, 9 figures, SPIE Astronomical Telescopes and Instrumentation
201
A spatial judgement task to determine background emotional state in laboratory rats (Rattus norvegicus)
Humans experiencing different background emotional states display contrasting cognitive (e.g. judgement) biases when responding to ambiguous stimuli. We have proposed that such biases may be used as indicators of animal emotional state. Here, we use a spatial judgement task, in which animals are trained to expect food in one location and not another, to determine whether rats in relatively positive or negative emotional states respond differently to ambiguous stimuli of intermediate spatial location. We housed 24 rats with environmental enrichment for seven weeks. Enrichment was removed for half the animals prior to the start of training (āUā: unenriched) to induce a relatively negative emotional state, whilst being left in place for the remaining rats (āEā: enriched). After six training days, the rats successfully discriminated between the rewarded and unrewarded locations in terms of an increased latency to arrive at the unrewarded location, with no housing treatment difference. The subjects then received three days of testing in which three ambiguous āprobeā locations, intermediate between the rewarded and unrewarded locations, were introduced. There was no difference between the treatments in the ratsā judgement of two out of the three probe locations, the exception being when the ambiguous probe was positioned closest to the unrewarded location. This result suggests that rats housed without enrichment, and in an assumed relatively negative emotional state, respond differently to an ambiguous stimulus compared to rats housed with enrichment, providing evidence that cognitive biases may be used to assess animal emotional state in a spatial judgement task
- ā¦