6,167 research outputs found
The PRIMA fringe sensor unit
The Fringe Sensor Unit (FSU) is the central element of the Phase Referenced
Imaging and Micro-arcsecond Astrometry (PRIMA) dual-feed facility and provides
fringe sensing for all observation modes, comprising off-axis fringe tracking,
phase referenced imaging, and high-accuracy narrow-angle astrometry. It is
installed at the Very Large Telescope Interferometer (VLTI) and successfully
servoed the fringe tracking loop during the initial commissioning phase. Unique
among interferometric beam combiners, the FSU uses spatial phase modulation in
bulk optics to retrieve real-time estimates of fringe phase after spatial
filtering. A R=20 spectrometer across the K-band makes the retrieval of the
group delay signal possible. The FSU was integrated and aligned at the VLTI in
summer 2008. It yields phase and group delay measurements at sampling rates up
to 2 kHz, which are used to drive the fringe tracking control loop. During the
first commissioning runs, the FSU was used to track the fringes of stars with
K-band magnitudes as faint as m_K=9.0, using two VLTI Auxiliary Telescopes (AT)
and baselines of up to 96 m. Fringe tracking using two Very Large Telescope
(VLT) Unit Telescopes (UT) was demonstrated. During initial commissioning and
combining stellar light with two ATs, the FSU showed its ability to improve the
VLTI sensitivity in K-band by more than one magnitude towards fainter objects,
which is of fundamental importance to achieve the scientific objectives of
PRIMA.Comment: 19 pages, 23 figures. minor changes and language editing. this
version equals the published articl
Optimising cosmic shear surveys to measure modifications to gravity on cosmic scales
We consider how upcoming photometric large scale structure surveys can be
optimized to measure the properties of dark energy and possible cosmic scale
modifications to General Relativity in light of realistic astrophysical and
instrumental systematic uncertainities. In particular we include flexible
descriptions of intrinsic alignments, galaxy bias and photometric redshift
uncertainties in a Fisher Matrix analysis of shear, position and position-shear
correlations, including complementary cosmological constraints from the CMB. We
study the impact of survey tradeoffs in depth versus breadth, and redshift
quality. We parameterise the results in terms of the Dark Energy Task Force
figure of merit, and deviations from General Relativity through an analagous
Modified Gravity figure of merit. We find that intrinsic alignments weaken the
dependence of figure of merit on area and that, for a fixed observing time, a
fiducial Stage IV survey plateaus above roughly 10,000deg2 for DE and peaks at
about 5,000deg2 as the relative importance of IAs at low redshift penalises
wide, shallow surveys. While reducing photometric redshift scatter improves
constraining power, the dependence is shallow. The variation in constraining
power is stronger once IAs are included and is slightly more pronounced for MG
constraints than for DE. The inclusion of intrinsic alignments and galaxy
position information reduces the required prior on photometric redshift
accuracy by an order of magnitude for both the fiducial Stage III and IV
surveys, equivalent to a factor of 100 reduction in the number of spectroscopic
galaxies required to calibrate the photometric sample.Comment: 13 pages, 6 figures. Fixed an error in equation 19 which changes the
right hand panels of figures 1 and 2, and modifies conclusions on the results
for fixed observing tim
Decomposition of Spectra from Redshift Distortion Maps
We develop an optimized technique to extract density--density and
velocity--velocity spectra out of observed spectra in redshift space. The
measured spectra of the distribution of halos from redshift distorted mock map
are binned into 2--dimensional coordinates in Fourier space so as to be
decomposed into both spectra using angular projection dependence. With the
threshold limit introduced to minimize nonlinear suppression, the decomposed
velocity--velocity spectra are reasonably well measured up to scale k=0.07
h/Mpc, and the measured variances using our method are consistent with errors
predicted from a Fisher matrix analysis. The detectability is extendable to
k\sim 0.1 h/Mpc with more conservative bounds at the cost of weakened
constraint.Comment: 5 pages and 4 figures, submitted to MNRA
Constraining Interactions in Cosmology's Dark Sector
We consider the cosmological constraints on theories in which there exists a
nontrivial coupling between the dark matter sector and the sector responsible
for the acceleration of the universe, in light of the most recent supernovae,
large scale structure and cosmic microwave background data. For a variety of
models, we show that the strength of the coupling of dark matter to a
quintessence field is constrained to be less than 7% of the coupling to
gravity. We also show that long range interactions between fermionic dark
matter particles mediated by a light scalar with a Yukawa coupling are
constrained to be less than 5% of the strength of gravity at a distance scale
of 10 Mpc. We show that all of the models we consider are quantum mechanically
weakly coupled, and argue that some other models in the literature are ruled
out by quantum mechanical strong coupling.Comment: 13 pages, 5 figure
Evaluation of harmful algal bloom outreach activities
This is the final version of the article. Available from MDPI via the link in this record.With an apparent increase of harmful algal blooms (HABs) worldwide, healthcare providers, public health personnel and coastal managers are struggling to provide scientifically-based appropriately-targeted HAB outreach and education. Since 1998, the Florida Poison Information Center-Miami, with its 24 hour/365 day/year free Aquatic Toxins Hotline (1-888-232-8635) available in several languages, has received over 25,000 HAB-related calls. As part of HAB surveillance, all possible cases of HAB-related illness among callers are reported to the Florida Health Department. This pilot study evaluated an automated call processing menu system that allows callers to access bilingual HAB information, and to speak directly with a trained Poison Information Specialist. The majority (68%) of callers reported satisfaction with the information, and many provided specific suggestions for improvement. This pilot study, the first known evaluation of use and satisfaction with HAB educational outreach materials, demonstrated that the automated system provided useful HAB-related information for the majority of callers, and decreased the routine informational call workload for the Poison Information Specialists, allowing them to focus on callers needing immediate assistance and their healthcare providers. These results will lead to improvement of this valuable HAB outreach, education and surveillance tool. Formal evaluation is recommended for future HAB outreach and educational materials.The funding for this study was provided by the Florida Department of Health and the Centers for Disease Control and Prevention (CDC) and Florida Harmful Algal Bloom Taskforce, as well as the National Science Foundation and National Institute of Environmental Health Sciences Oceans and Human Health Center at the University of Miami Rosenstiel School (NSF 0CE0432368; NIEHS 1 P50 ES12736), the former National Institute of Environmental Health Sciences Marine and Freshwater Biomedical Sciences Center at the University of Miami Rosenstiel School (NIEHS P30ES05705), and the National Institute of Environmental Health Sciences Red Tide POI (P01 ES 10594)
Defining and cataloging exoplanets: The exoplanet.eu database
We describe an online database for extra-solar planetary-mass candidates,
updated regularly as new data are available. We first discuss criteria for the
inclusion of objects in the catalog: "definition" of a planet and several
aspects of the confidence level of planet candidates. {\bf We are led to point
out the conflict between sharpness of belonging or not to a catalogue and
fuzziness of the confidence level.} We then describe the different tables of
extra-solar planetary systems, including unconfirmed candidates (which will
ultimately be confirmed, or not, by direct imaging). It also provides online
tools: histogrammes of planet and host star data, cross-correlations between
these parameters and some VO services. Future evolutions of the database are
presented.Comment: Accepted in Astronomy and Astrophysics (revised version
Vagal sensory neurons drive mucous cell metaplasia
Summary:
Airway sensory neuron-produced Substance P heightens allergy-induced goblet cell hyperplasia and hypersecretion of Muc5AC, electrically silencing these overreactive neurons reduced these components of lung type 2 allergic inflammatory response
Augmentative Approaches in Family‐Based Treatment for Adolescents with Restrictive Eating Disorders: A Systematic Review
ObjectiveTo systematically review the literature reporting outcomes of augmentative family‐based treatment (FBT) interventions for adolescents with restrictive eating disorders (EDs).MethodArticles were identified through a systematic search of five electronic databases (PsycINFO, MEDLINE, EMBASE, CINAHL, Cochrane Database).ResultsThirty articles were included, reporting on FBT augmentations featuring adjunctive treatment components, modified treatment structure and/or content with adherence to FBT principles, and adaptations allowing FBT delivery in different settings. All reported significant improvements in weight and/or ED symptoms at end‐of‐treatment, although few compared augmentative and standard FBT interventions and good quality follow‐up data was generally lacking.ConclusionsThere is early evidence for the effectiveness of augmentative FBT‐based approaches in facilitating weight and/or ED symptom improvements for adolescents with restrictive EDs. There remains a lack of robust evidence demonstrating superior effects of such approaches over standard FBT, and further controlled studies are required to expand on the current evidence. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142429/1/erv2577.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142429/2/erv2577_am.pd
Morphological and physiological changes in tetrahymena pyriformis for the in vitro cytotoxicity assessment of triton X-100
Non-ionic surfactants such as Triton X-100 have been widely used in industrial processing and in cleaning products for almost 50
years, being effective and economic emulsifying, wetting agents, dispersants and solubilizers. Cleaning products containing these
surfactants are disposed of mainly by discharge into wastewater, which receives biological treatment in wastewater treatment systems.
However, surface-active agents interact with eukaryotic cell membranes leading to biological damage at high concentrations.
Tetrahymena pyriformis was used here as model organism to assess the effects of Triton X-100 through a series of in vitro cytotoxicity
tests. Growth rates and morphological changes were, by their simplicity and reproducibility, the simplest toxicological
assays. Cytoskeleton analysis seemed to be related with phagocytosis rate. Viability was evaluated by two different tests. Calcein
AM/EthD-1 was used to assess T. pyriformis membrane damage during the 48-h experiment. The colorimetric MTT assay proved
to be highly sensitive even at very short periods of Triton X-100 exposure. Tests performed in this study included simple and fast
bioassays that provide overall information on the morphological and physiological state of cells exposed to different non-lytic and
lytic concentrations of Triton X-100.Fundação para a Ciência e a Tecnologia (FCT) - PRAXIS XXI/BD/20328/99 - Instituto de Biotecnologia e Química Fina (IBQF).
Fundação de Amparo à Pesquisa do Estado de SP (FAPESP).
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).
Revista de Atualização Médica ( RAM)
Penetration of Josephson vortices and measurement of the c-axis penetration depth in : Interplay of Josephson coupling, surface barrier and defects
The first penetration field H_{J}(T) of Josephson vortices is measured
through the onset of microwave absorption in the locked state, in slightly
overdoped single crystals (T_{c} ~ 84
K). The magnitude of H_{J}(T) is too large to be accounted for by the first
thermodynamic critical field H_{c1}(T). We discuss the possibility of a
Bean-Livingston barrier, also supported by irreversible behavior upon flux
exit, and the role of defects, which relates H_{J}(T) to the c-axis penetration
depth . The temperature dependence of the latter, determined by
a cavity perturbation technique and a theoretical estimate of the
defect-limited penetration field are used to deduce from H_{J}(T) the absolute
value of .Comment: 9 pages, 6 figure
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