1,071 research outputs found
The potential of Manitoba chokecherry as a source of high natural antioxidants
Consumption of fruits and vegetables is shown to be beneficial for protecting health and preventing some chronic diseases such as cancer, cardiovascular disease, and stroke. The positive health effects have been mainly due to the contributions of their natural antioxidant capacity. Chokecherry (Prunus virginiana), a unique fruit, is a member of the Rose family and native to North America. Here we demonstrate that chokecherry fruit with strong antioxidant capacity is available in Manitoba, and that its potent antioxidant potential can be developed for health benefits in value-added applications.These findings are useful for developing novel value-added antioxidant products from chokecherry because of its phytochemical profile associated with health protection and prevention of disease. The results provide evidence essential for breeding novel cultivars of fruit plants with strong natural antioxidants
Quantitative atomic spectroscopy for primary thermometry
Quantitative spectroscopy has been used to measure accurately the
Doppler-broadening of atomic transitions in Rb vapor. By using a
conventional platinum resistance thermometer and the Doppler thermometry
technique, we were able to determine with a relative uncertainty of
, and with a deviation of from the
expected value. Our experiment, using an effusive vapour, departs significantly
from other Doppler-broadened thermometry (DBT) techniques, which rely on weakly
absorbing molecules in a diffusive regime. In these circumstances, very
different systematic effects such as magnetic sensitivity and optical pumping
are dominant. Using the model developed recently by Stace and Luiten, we
estimate the perturbation due to optical pumping of the measured value
was less than . The effects of optical pumping on atomic and
molecular DBT experiments is mapped over a wide range of beam size and
saturation intensity, indicating possible avenues for improvement. We also
compare the line-broadening mechanisms, windows of operation and detection
limits of some recent DBT experiments
Iron porphyrin molecules on Cu(001): Influence of adlayers and ligands on the magnetic properties
The structural and magnetic properties of Fe octaethylporphyrin (OEP)
molecules on Cu(001) have been investigated by means of density functional
theory (DFT) methods and X-ray absorption spectroscopy. The molecules have been
adsorbed on the bare metal surface and on an oxygen-covered surface, which
shows a reconstruction. In order to allow
for a direct comparison between magnetic moments obtained from sum-rule
analysis and DFT we calculate the dipolar term , which is also
important in view of the magnetic anisotropy of the molecule. The measured
X-ray magnetic circular dichroism shows a strong dependence on the photon
incidence angle, which we could relate to a huge value of , e.g. on
Cu(001) amounts to -2.07\,\mbo{} for normal incidence leading to a
reduction of the effective spin moment . Calculations have also
been performed to study the influence of possible ligands such as Cl and O
atoms on the magnetic properties of the molecule and the interaction between
molecule and surface, because the experimental spectra display a clear
dependence on the ligand, which is used to stabilize the molecule in the gas
phase. Both types of ligands weaken the hybridization between surface and
porphyrin molecule and change the magnetic spin state of the molecule, but the
changes in the X-ray absorption are clearly related to residual Cl ligands.Comment: 17 figures, full articl
The CARMENES search for exoplanets around M dwarfs - Photospheric parameters of target stars from high-resolution spectroscopy
The new CARMENES instrument comprises two high-resolution and high-stability
spectrographs that are used to search for habitable planets around M dwarfs in
the visible and near-infrared regime via the Doppler technique. Characterising
our target sample is important for constraining the physical properties of any
planetary systems that are detected. The aim of this paper is to determine the
fundamental stellar parameters of the CARMENES M-dwarf target sample from
high-resolution spectra observed with CARMENES. We also include several M-dwarf
spectra observed with other high-resolution spectrographs, that is CAFE, FEROS,
and HRS, for completeness. We used a {chi}^2 method to derive the stellar
parameters effective temperature T_eff, surface gravity log g, and metallicity
[Fe/H] of the target stars by fitting the most recent version of the
PHOENIX-ACES models to high-resolution spectroscopic data. These stellar
atmosphere models incorporate a new equation of state to describe spectral
features of low-temperature stellar atmospheres. Since T_eff, log g, and [Fe/H]
show degeneracies, the surface gravity is determined independently using
stellar evolutionary models. We derive the stellar parameters for a total of
300 stars. The fits achieve very good agreement between the PHOENIX models and
observed spectra. We estimate that our method provides parameters with
uncertainties of {sigma} T_eff = 51 K, {sigma} log g = 0.07, and {sigma} [Fe/H]
= 0.16, and show that atmosphere models for low-mass stars have significantly
improved in the last years. Our work also provides an independent test of the
new PHOENIX-ACES models, and a comparison for other methods using
low-resolution spectra. In particular, our effective temperatures agree well
with literature values, while metallicities determined with our method exhibit
a larger spread when compared to literature results
ParkIndex: Validation and Application of a Pragmatic Measure of Park Access and Use
Composite metrics integrating park availability, features, and quality for a given address or neighborhood are lacking. The purposes of this study were to describe the validation, application, and demonstration of ParkIndex in four diverse communities. This study occurred in Fall 2018 in 128 census block groups within Seattle(WA), Brooklyn(NY), Raleigh(NC), and Greenville County(SC). All parks within a half-mile buffer were audited to calculate a composite park quality score, and select households provided data about use of proximal parks via an online, map-based survey. For each household, the number of parks, total park acreage, and average park quality score within one half-mile were calculated using GIS. Logistic regression was used to identify a parsimonious model predicting park use. ParkIndex values (representing the probability of park use) were mapped for all study areas and after scenarios involving the addition and renovation/improvement of parks. Out of 360 participants, 23.3% reported visiting a park within the past 30âŻdays. The number of parks (ORâŻ=âŻ1.36, 95% CIâŻ=âŻ1.15â1.62), total park acreage (ORâŻ=âŻ1.13, 95% CIâŻ=âŻ1.07â1.19), and average park quality score (ORâŻ=âŻ1.04, 95% CIâŻ=âŻ1.01â1.06) within one half-mile were all associated with park use. Composite ParkIndex values across the study areas ranged from 0 to 100. Hypothetical additions of or renovations to study area parks resulted in ParkIndex increases of 22.7% and 19.2%, respectively. ParkIndex has substantial value for park and urban planners, citizens, and researchers as a common metric to facilitate awareness, decision-making, and intervention planning related to park access, environmental justice, and community health
Thermobaric Effect on Melt-Textured MBaCuO (M = Y, Nd)
The effect of a short (10-30 min) thermobaric action (in the 1-5 GPa pressure
and 700-1300C temperature range) on the structure, superconductive and
mechanical properties of melt-textured-MBaCuO (M=Y, Nd) or
MT-MBCO have been studied. The existence has been established of
pressure-temperature--time conditions (2 GPa, 800C for 30 min and
900-950C for 15 min for MT-YBCO; 5 GPa, 850-900C for 15 min for
MT-NdBCO) the treatment under which allows superconductive properties of the
materials (because of the contact with zirconia and high pressure) to be
preserved or improved, mechanical characteristics increased and the materials
condensed.Comment: 2 pages (tex), 2 figures (eps), to be presented at LT2
Association of Plasma 25Ăą Hydroxyvitamin D Concentrations and Pathogenic Oral Bacteria in Postmenopausal Females
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141146/1/jper0944.pd
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