327 research outputs found
Multiplex analysis of osteoarthritic synovial fluid: a comparison of Luminex & Mesoscale discovery
High speed fundus photography or optical coherence tomography angiography - which one is better for non-invasive capillary perfusion maps and velocity measurements?
Detection of Metal-Rich, Cool-Warm Gas in the Outskirts of Galaxy Clusters
We present an ultraviolet quasar absorption line analysis of metal lines
associated with three strong intervening H I absorbers (with (H I)
10 cm) detected in the outskirts of Sunyaev-Zel'dovich (SZ)
effect-selected galaxy clusters (), within
clustocentric impact parameters of .
Discovered in a recent set of targeted far-UV /COS spectroscopic
observations, these absorbers have the highest H I column densities ever
observed in the outskirts of galaxy clusters, and are also rich in metal
absorption lines. Photoionization models yield single phase solutions for the
three absorbers with gas densities of cm
and metallicities of [X/H] -1.0 (from one-tenth solar to near-solar). The
widths of detected absorption lines suggest gas temperatures of
K. The inferred densities (temperatures) are significantly higher (lower)
compared to the X-ray emitting intracluster medium in cluster cores. The
absorbers are tracing a cool phase of the intracluster gas in the cluster
outskirts, either associated with gas stripped from cluster galaxies via
outflows, tidal streams or ram-pressure forces, or denser regions within the
intracluster medium that were uniformly chemically enriched from an earlier
epoch of enhanced supernova and AGN feedback.Comment: 13 pages, 6 figures, 2 tables. Accepted for publication in MNRA
Whale shark Rhincodon typus landed at Cooperage landing centre, Bombay
On 16-03-1993 a female Whale shark,
which got entangled in a monofilament gill net (14
cm mesh size) was landed alive at Cooperage
landing centre, Bombay at 1000 hrs and died at
about 1400 hrs
Mid-Infrared interferometry of dust around massive evolved stars
We report long-baseline interferometric measurements of circumstellar dust
around massive evolved stars with the MIDI instrument on the Very Large
Telescope Interferometer and provide spectrally dispersed visibilities in the
8-13 micron wavelength band. We also present diffraction-limited observations
at 10.7 micron on the Keck Telescope with baselines up to 8.7 m which explore
larger scale structure. We have resolved the dust shells around the late type
WC stars WR 106 and WR 95, and the enigmatic NaSt1 (formerly WR 122), suspected
to have recently evolved from a Luminous Blue Variable (LBV) stage. For AG Car,
the protoypical LBV in our sample, we marginally resolve structure close to the
star, distinct from the well-studied detached nebula. The dust shells around
the two WC stars show fairly constant size in the 8-13 micron MIDI band, with
gaussian half-widths of ~ 25 to 40 mas. The compact dust we detect around NaSt1
and AG Car favors recent or ongoing dust formation.
Using the measured visibilities, we build spherically symmetric radiative
transfer models of the WC dust shells which enable detailed comparison with
existing SED-based models. Our results indicate that the inner radii of the
shells are within a few tens of AU from the stars. In addition, our models
favor grain size distributions with large (~ 1 micron) dust grains. This
proximity of the inner dust to the hot central star emphasizes the difficulty
faced by current theories in forming dust in the hostile environment around WR
stars. Although we detect no direct evidence for binarity for these objects,
dust production in a colliding-wind interface in a binary system is a feasible
mechanism in WR systems under these conditions.Comment: 21 pages, 4 tables, 13 figures. Accepted for publication in the
Astrophysical Journa
Solar Contamination in Extreme-precision Radial-velocity Measurements: Deleterious Effects and Prospects for Mitigation
Solar contamination, due to moonlight and atmospheric scattering of sunlight, can cause systematic errors in stellar radial velocity (RV) measurements that significantly detract from the ~10 cm s−1 sensitivity required for the detection and characterization of terrestrial exoplanets in or near habitable zones of Sun-like stars. The addition of low-level spectral contamination at variable effective velocity offsets introduces systematic noise when measuring velocities using classical mask-based or template-based cross-correlation techniques. Here we present simulations estimating the range of RV measurement error induced by uncorrected scattered sunlight contamination. We explore potential correction techniques, using both simultaneous spectrometer sky fibers and broadband imaging via coherent fiber imaging bundles, that could reliably reduce this source of error to below the photon-noise limit of typical stellar observations. We discuss the limitations of these simulations, the underlying assumptions, and mitigation mechanisms. We also present and discuss the components designed and built into the NEID (NN-EXPLORE Exoplanet Investigations with Doppler spectroscopy) precision RV instrument for the WIYN 3.5 m telescope, to serve as an ongoing resource for the community to explore and evaluate correction techniques. We emphasize that while "bright time" has been traditionally adequate for RV science, the goal of 10 cm s−1 precision on the most interesting exoplanetary systems may necessitate access to darker skies for these next-generation instruments
A note on the recurring heavy catch of ‘Ghol’, Protonibea diacanthus by dol net at Bassien koliwada, Maharasthtra.
Protonibea diacanthus, locally known as‘Ghol’ is one of the most commercially important fishes of northwest coast of India. The swim bladder of ‘Ghol’ fetches a very high market price as it is considered as one of the best qualities.On 28-10-06 catch of 8820 Kg of ‘Ghol was landed at Bassien koliwada by a dol net boat with an OAL of 15 m fitted with 90 HP engine
Comparison of Pittsburgh compound B and florbetapir in cross-sectional and longitudinal studies.
IntroductionQuantitative in vivo measurement of brain amyloid burden is important for both research and clinical purposes. However, the existence of multiple imaging tracers presents challenges to the interpretation of such measurements. This study presents a direct comparison of Pittsburgh compound B-based and florbetapir-based amyloid imaging in the same participants from two independent cohorts using a crossover design.MethodsPittsburgh compound B and florbetapir amyloid PET imaging data from three different cohorts were analyzed using previously established pipelines to obtain global amyloid burden measurements. These measurements were converted to the Centiloid scale to allow fair comparison between the two tracers. The mean and inter-individual variability of the two tracers were compared using multivariate linear models both cross-sectionally and longitudinally.ResultsGlobal amyloid burden measured using the two tracers were strongly correlated in both cohorts. However, higher variability was observed when florbetapir was used as the imaging tracer. The variability may be partially caused by white matter signal as partial volume correction reduces the variability and improves the correlations between the two tracers. Amyloid burden measured using both tracers was found to be in association with clinical and psychometric measurements. Longitudinal comparison of the two tracers was also performed in similar but separate cohorts whose baseline amyloid load was considered elevated (i.e., amyloid positive). No significant difference was detected in the average annualized rate of change measurements made with these two tracers.DiscussionAlthough the amyloid burden measurements were quite similar using these two tracers as expected, difference was observable even after conversion into the Centiloid scale. Further investigation is warranted to identify optimal strategies to harmonize amyloid imaging data acquired using different tracers
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