2,728 research outputs found
Induction of mammary neoplasms in the ACI rat by 430-keV neutrons, X-rays, and diethylstilbestrol
Symptoms and Self-Care in Old Age
Self-care has recently come to be recognized as the predominant form of response to illness among the general population, but little is known regarding beliefs and practices of the aged. In this study, beliefs regarding the appropriate response to 53 common symptoms were investigated and contrasted to actual responses. Various forms of self-care were seen as appropriate responses to symptoms ranging from minor to potentially serious. Preference for self-care responses appears to be related to perceived severity of symptoms and the perceived effectiveness of available self-care responses.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66474/2/10.1177_073346488600500207.pd
Evaluation of the soil moisture prediction accuracy of a space radar using simulation techniques
Image simulation techniques were employed to generate synthetic aperture radar images of a 17.7 km x 19.3 km test site located east of Lawrence, Kansas. The simulations were performed for a space SAR at an orbital altitude of 600 km, with the following sensor parameters: frequency = 4.75 GHz, polarization = HH, and angle of incidence range = 7 deg to 22 deg from nadir. Three sets of images were produced corresponding to three different spatial resolutions; 20 m x 20 m with 12 looks, 100 m x 100 m with 23 looks, and 1 km x 1 km with 1000 looks. Each set consisted of images for four different soil moisture distributions across the test site. Results indicate that, for the agricultural portion of the test site, the soil moisture in about 90% of the pixels can be predicted with an accuracy of = + or - 20% of field capacity. Among the three spatial resolutions, the 1 km x 1 km resolution gave the best results for most cases, however, for very dry soil conditions, the 100 m x 100 m resolution was slightly superior
Using Astrometry to Deblend Microlensing Events
We discuss the prospect of deblending microlensing events by observing
astrometric shifts of the lensed stars. Since microlensing searches are
generally performed in very crowded fields, it is expected that stars will be
confusion limited rather than limited by photon statistics. By performing
simulations of events in crowded fields, we find that if we assume a dark lens
and that the lensed star obeys a power law luminosity function, , over half the simulated events show a measurable astrometric
shift. Our simulations included 20000 stars in a Nyquist
sampled CCD frame. For , we found that 58% of the events were
significantly blended , and of those, 73% had a
large astrometric shift . Likewise, for , we found
that 85% of the events were significantly blended, and that 85% of those had
large shifts. Moreover, the shift is weakly correlated to the degree of
blending, suggesting that it may be possible not only to detect the existence
of a blend, but also to deblend events statistically using shift information.Comment: 24 pages, 7 postscript Figure
Mixed Dark Matter from Axino Distribution
We study the possibility of mixed dark matter obtained through the phase
space distribution of a single particle. An example is offered in the context
of SUSY models with a Peccei-Quinn symmetry. Axinos in the 100 keV range can
naturally have both thermal and non-thermal components. The latter one arises
from the lightest neutralino decays and derelativizes at z ~ 10^4.Comment: Figures added, references fixed. Version accepted for publication on
Phys. Rev. D. LaTeX. 9 pages, 3 figures, uses epsfig.st
Independent study demonstrates amyloid probability score accurately indicates amyloid pathology
BACKGROUND: The amyloid probability score (APS) is the model read-out of the analytically validated mass spectrometry-based PrecivityAD
PURPOSE: This study aimed to provide additional independent evidence that the pre-established APS algorithm, along with its cutoff values, discriminates between amyloid positive and negative individuals.
METHODS: The diagnostic performance of the PrecivityAD test was analyzed in a cohort of 200 nonrandomly selected Australian Imaging, Biomarker & Lifestyle Flagship Study of Aging (AIBL) study participants, who were either cognitively impaired or healthy controls, and for whom a blood sample and amyloid PET imaging were available.
RESULTS: In a subset of the dataset aligned with the Intended Use population (patients aged 60 and older with CDR ≥0.5), the pre-established APS algorithm predicted amyloid PET with a sensitivity of 84.9% (CI: 72.9-92.1%) and specificity of 96% (CI: 80.5-99.3%), exclusive of 13 individuals for whom the test was inconclusive.
INTERPRETATION: The study shows individuals with a high APS are more likely than those with a low APS to have abnormal amounts of amyloid plaques and be on an amyloid accumulation trajectory, a dynamic and evolving process characteristic of progressive AD pathology. Exploratory data suggest APS retains its diagnostic performance in healthy individuals, supporting further screening studies in the cognitively unimpaired
BEAMS: separating the wheat from the chaff in supernova analysis
We introduce Bayesian Estimation Applied to Multiple Species (BEAMS), an
algorithm designed to deal with parameter estimation when using contaminated
data. We present the algorithm and demonstrate how it works with the help of a
Gaussian simulation. We then apply it to supernova data from the Sloan Digital
Sky Survey (SDSS), showing how the resulting confidence contours of the
cosmological parameters shrink significantly.Comment: 23 pages, 9 figures. Chapter 4 in "Astrostatistical Challenges for
the New Astronomy" (Joseph M. Hilbe, ed., Springer, New York, forthcoming in
2012), the inaugural volume for the Springer Series in Astrostatistic
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