1,274 research outputs found
FOOD STAMP PARTICIPATION AMONG LOW-INCOME HOUSEHOLDS: THEORETICAL CONSIDERATIONS OF THE IMPACT ON THE DEMAND FOR FOOD
Food Consumption/Nutrition/Food Safety,
TRADITIONAL AND NONTRADITIONAL DETERMINANTS OF HOUSEHOLD EXPENDITURES ON SELECTED FRUITS AND VEGETABLES
Nontraditional variables such as liquid assets, households management style, and psychological levels influence both the type and variety of fruits and vegetables served by Washington households. Among traditional variables, household size, education levels, and geographic area within Washington State are relatively important factors. Income and occupation are relatively weak as explanatory variables. The liquid asset levels consume a larger amount and a greater variety of fruits and vegetables.Food Consumption/Nutrition/Food Safety,
Photolytically generated aerosols in the mesosphere and thermosphere of Titan
Analysis of the Cassini Ultraviolet Imaging Spectrometer (UVIS) stellar and
solar occultations at Titan to date include 12 species: N (nitrogen),
CH (methane), CH (acetylene), CH (ethylene),
CH (ethane), CH (diacetylene), CH
(benzene), CN (dicyanodiacetylene), CN (cyanogen), HCN
(hydrogen cyanide), HCN (cyanoacetylene), and aerosols distinguished by a
structureless continuum extinction (absorption plus scattering) of photons in
the EUV. The introduction of aerosol particles, retaining the same refractive
index properties as tholin with radius 125 \AA and using Mie theory,
provides a satisfactory fit to the spectra. The derived vertical profile of
aerosol density shows distinct structure, implying a reactive generation
process reaching altitudes more than 1000 km above the surface. A photochemical
model presented here provides a reference basis for examining the chemical and
physical processes leading to the distinctive atmospheric opacity at Titan. We
find that dicyanodiacetylene is condensable at 650 km, where the
atmospheric temperature minimum is located. This species is the simplest
molecule identified to be condensable. Observations are needed to confirm the
existence and production rates of dicyanodiacetylene.Comment: A typo in Table 1 was made in the previous version. The corrected
tholin abundance is 4.6x10^11. ApJL in press. Will be published on June 1st,
or May 21 onlin
BOSS Ultracool Dwarfs I: Colors and Magnetic Activity of M and L dwarfs
We present the colors and activity of ultracool (M7-L8) dwarfs from the Tenth
Data Release of the Sloan Digital Sky Survey (SDSS). We combine previous
samples of SDSS M and L dwarfs with new data obtained from the Baryon
Oscillation Sky Survey (BOSS) to produce the BOSS Ultracool Dwarf (BUD) sample
of 11820 M7-L8 dwarfs. By combining SDSS data with photometry from the Two
Micron All Sky Survey and the Wide-Field Infrared Sky Explorer mission, we
present ultracool dwarf colors from to as a function of spectral
type, and extend the SDSS-2MASS-WISE color locus to include ultracool dwarfs.
The , , and colors provide the best indication of spectral type
for M7-L3 dwarfs. We also examine ultracool dwarf chromospheric activity
through the presence and strength of H emission. The fraction of active
dwarfs rises through the M spectral sequence until it reaches 90% at
spectral type L0. The fraction of active dwarfs then declines to 50% at
spectral type L5; no H emission is observed in the late-L dwarfs in the
BUD sample. The fraction of active L0-L5 dwarfs is much higher than previously
observed. The strength of activity declines with spectral type from M7 through
L3, after which the data do not show a clear trend. Using one-dimensional
chromosphere models, we explore the range of filling factors and chromospheric
temperature structures that are consistent with H observations of M0-L7
dwarfs. M dwarf chromospheres have a similar, smoothly varying range of
temperature and surface coverage while L dwarf chromospheres are cooler and
have smaller filling factors.Comment: 24 pages and 13 figures, submitted to AJ. A short video describing
these results can be found at https://www.youtube.com/watch?v=wwX5WkuJCU
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Methods for modifying cell contact with a surface
Described herein is a multi-functional polymeric material for use in inhibiting adhesion and immune recognition between cells and cells, cells and tissues, and tissues and tissues. One component of the polymeric material adsorbs well to cells or tissue, and the other component of the polymeric material does not adsorb well to tissues. A water-soluble polymer that does not bear charge (polynonion) is used as the non-binding component, and a water soluble polymer that is positively charged at physiological pH (polycation) is used as the tissue binding component. When the bi-functional polymeric material contacts a tissue, the tissue-binding component binds and thus immobilizes the attached non-binding component, which will then extend generally away from the tissue surface and sterically block the attachment of other tissues. The method and compositions are useful in inhibiting formation of post-surgical adhesions, protecting damaged blood vessels from thrombosis and restenosis, and decreasing the extent of metastasis of attachment-dependent tumor cells.Board of Regents, University of Texas Syste
Associations of maternal vitamin D, PTH and calcium with hypertensive disorders of pregnancy and associated adverse perinatal outcomes:Findings from the Born in Bradford cohort study
Abstract Vitamin D and parathyroid hormone (PTH) regulate mineral metabolism and are required to maintain calcium levels. Vitamin D deficiency is common, particularly during pregnancy, and has been associated with hypertensive disorders of pregnancy. We sought to determine whether maternal 25(OH)D, PTH and calcium concentrations at 26 weeks gestation are associated with adverse outcomes of pregnancy and establish whether these differ by ethnicity. This study included 476 White British and 534 Pakistani origin mother-offspring pairs from the Born in Bradford cohort study. We used multinomial or logistic regression to explore the association between vitamin D, PTH and calcium with gestational hypertension (GH), pre-eclampsia (PE), caesarean section (CS), preterm birth (PTB) and small for gestational age (SGA). Pakistani women had lower 25(OH)D (median 13.0 vs 36.0 nmol/L), higher PTH (median 7.7 vs 3.3 pmol/L) and similar calcium concentrations compared to White British women. In Pakistani women, higher concentrations of 25(OH)D were associated with a 60% increased odds of GH, and a 37% reduced odds of SGA; PTH was associated with a 45% reduction in the odds of GH. In White British women, each 1 SD increase in calcium concentration was associated with a 34% increase in developing GH but a 33% reduction in the odds of PTB. Associations with PE and CS were consistent with the null. In conclusion, there are ethnic differences in the associations of 25(OH)D, PTH and calcium with important perinatal outcomes. Future research would benefit from examining the associations of 25(OH)D, PTH and calcium together with a range of perinatal outcomes in order to assess the risk-benefit action of each
Exploring the Local Milky Way: M Dwarfs as Tracers of Galactic Populations
We have assembled a spectroscopic sample of low-mass dwarfs observed as part
of the Sloan Digital Sky Survey along one Galactic sightline, designed to
investigate the observable properties of the thin and thick disks. This sample
of ~7400 K and M stars also has measured ugriz photometry, proper motions, and
radial velocities. We have computed UVW space motion distributions, and
investigate their structure with respect to vertical distance from the Galactic
Plane. We place constraints on the velocity dispersions of the thin and thick
disks, using two-component Gaussian fits. We also compare these kinematic
distributions to a leading Galactic model. Finally, we investigate other
possible observable differences between the thin and thick disks, such as
color, active fraction and metallicity.Comment: 11 pages, 12 figures, Accepted by A
Study design considerations for the Standardized Treatment of Pulmonary Exacerbations 2 (STOP2): A trial to compare intravenous antibiotic treatment durations in CF
BACKGROUND:
Pulmonary exacerbations (PEx) in cystic fibrosis (CF) are common and contribute to morbidity and mortality. Duration of IV antibiotic therapy to treat PEx varies widely in the US, and there are few data to guide treatment decisions.
METHODS:
We combined a survey of CF stakeholders with retrospective analyses of a recent observational study of CF PEx to design a multicenter, randomized, prospective study comparing the efficacy and safety of different durations of IV antibiotics for PEx to meet the needs of people with CF and their caregivers.
RESULTS:
IV antibiotic duration was cited as the most important PEx research question by responding CF physicians and top concern among surveyed CF patients/caregivers. During PEx, forced expiratory volume in 1s (FEV1% predicted) and symptom responses at 7-10days of IV antibiotics identified two distinct groups: early robust responders (ERR) who subsequently experienced greater FEV1 improvements compared to non-ERR (NERR). In addition to greater FEV1 and symptom responses, only 14% of ERR patients were treated with IV antibiotics for >15days, compared with 45% of NERR patients.
CONCLUSIONS:
A divergent trial design that evaluates subjects' interim improvement in FEV1 and symptoms to tailor randomization to IV treatment duration (10 vs. 14days for ERR, 14 vs. 21days for NERR) may alleviate physician and patient concerns about excess or inadequate treatment. Such a study has the potential to provide evidence necessary to standardize IV antibiotic duration in CF PEx care -a first step to conducting PEx research of other treatment features
Computer-aided assessment of diagnostic images for epidemiological research
<p>Abstract</p> <p>Background</p> <p>Diagnostic images are often assessed for clinical outcomes using subjective methods, which are limited by the skill of the reviewer. Computer-aided diagnosis (CAD) algorithms that assist reviewers in their decisions concerning outcomes have been developed to increase sensitivity and specificity in the clinical setting. However, these systems have not been well utilized in research settings to improve the measurement of clinical endpoints. Reductions in bias through their use could have important implications for etiologic research.</p> <p>Methods</p> <p>Using the example of cortical cataract detection, we developed an algorithm for assisting a reviewer in evaluating digital images for the presence and severity of lesions. Available image processing and statistical methods that were easily implementable were used as the basis for the CAD algorithm. The performance of the system was compared to the subjective assessment of five reviewers using 60 simulated images. Cortical cataract severity scores from 0 to 16 were assigned to the images by the reviewers and the CAD system, with each image assessed twice to obtain a measure of variability. Image characteristics that affected reviewer bias were also assessed by systematically varying the appearance of the simulated images.</p> <p>Results</p> <p>The algorithm yielded severity scores with smaller bias on images where cataract severity was mild to moderate (approximately ≤ 6/16<sup><it>ths</it></sup>). On high severity images, the bias of the CAD system exceeded that of the reviewers. The variability of the CAD system was zero on repeated images but ranged from 0.48 to 1.22 for the reviewers. The direction and magnitude of the bias exhibited by the reviewers was a function of the number of cataract opacities, the shape and the contrast of the lesions in the simulated images.</p> <p>Conclusion</p> <p>CAD systems are feasible to implement with available software and can be valuable when medical images contain exposure or outcome information for etiologic research. Our results indicate that such systems have the potential to decrease bias and discriminate very small changes in disease severity. Simulated images are a tool that can be used to assess performance of a CAD system when a gold standard is not available.</p
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