492 research outputs found
Resolving the nucleus of Centaurus A at mid-IR wavelengths
We have observed Centaurus A with the MID-infrared Interferometric instrument
(MIDI) at the Very Large Telescope Interferometer (VLTI) at resolutions of 7 -
15 mas (at 12.5 micron) and filled gaps in the (u,v) coverage in comparison to
earlier measurements. We are now able to describe the nuclear emission in terms
of geometric components and derive their parameters by fitting models to the
interferometric data. With simple geometrical models, the best fit is achieved
for an elongated disk with flat intensity profile with diameter 76 +/- 9 mas x
35 +/- 2 mas (1.41 +/- 0.17 pc x 0.65 +/- 0.03 pc) whose major axis is oriented
at a position angle (PA) of 10.1 +/- 2.2 degrees east of north. A point source
contributes 47 +/- 11 % of the nuclear emission at 12.5 micron. There is also
evidence that neither such a uniform nor a Gaussian disk are good fits to the
data. This indicates that we are resolving more complicated small-scale
structure in AGNs with MIDI, as has been seen in Seyfert galaxies previously
observed with MIDI. The PA and inferred inclination i = 62.6 +2.1/-2.6 degrees
of the dust emission are compared with observations of gas and dust at larger
scales.Comment: Accepted for the PASA special issue on Centaurus
One-step facial feminization surgery: The importance of a custom-made preoperative planning and patient satisfaction assessment
Background: The availability of more accurate techniques used for transgender surgery has resulted in an increased number of patients requesting facial feminization surgery (FFS). The aim of this study was to present the FFS pre-operative planning of the authors’ male-to-female transsexual patients using photo-editing software, computer-aided design (CAD), modeling, and three-dimensional (3D) printing. Material and Methods: Twenty-five patients underwent FFS between November 2015 and May 2018. They were retrospectively included in this study, and their records were analyzed. Patients’ 3D facial models were printed and used for an accurate preoperative planning and shown to the patients. To assess patient satisfaction, the preoperative, six-month, and one-year postoperative scores obtained using Satisfaction With Life Scale (SWLS) and Subjective Happiness Scale (SHS) were compared. The scores following a normal distribution obtained for each patient were compared using a paired t-test. Results: The 3D model preparation mean time was 145±13.2 min. A total of 114 surgical procedures were carried out. The mean operative time was 420±23 min. Patients experienced no postoperative complication. All patients were very satisfied after surgery, with a significant difference between pre- and postoperative scores (p = 0.002; p = 0.03). Conclusion: With use of 3D modeling, surgeons are nearing a custom-made surgery era, especially required for complex procedures such as FFS. We suggest using 3D technology for a more accurate preoperative planning
13. Expérience d’une unité de chirurgie reconstructrice pour les résections pariétales étendues en chirurgie carcinologique mammaire
Improving the surface brightness-color relation for early-type stars using optical interferometry
The aim of this work is to improve the SBC relation for early-type stars in
the color domain, using optical interferometry.
Observations of eight B- and A-type stars were secured with the VEGA/CHARA
instrument in the visible. The derived uniform disk angular diameters were
converted into limb darkened angular diameters and included in a larger sample
of 24 stars, already observed by interferometry, in order to derive a revised
empirical relation for O, B, A spectral type stars with a V-K color index
ranging from -1 to 0. We also took the opportunity to check the consistency of
the SBC relation up to using 100 additional measurements. We
determined the uniform disk angular diameter for the eight following stars:
Ori, Per, Cyg, Her, Aql, Peg,
Lyr, and Cyg with V-K color ranging from -0.70 to 0.02 and
typical precision of about . Using our total sample of 132 stars with
colors index ranging from about to , we provide a revised SBC
relation. For late-type stars (), the results are consistent
with previous studies. For early-type stars (), our new
VEGA/CHARA measurements combined with a careful selection of the stars
(rejecting stars with environment or stars with a strong variability), allows
us to reach an unprecedented precision of about 0.16 magnitude or
in terms of angular diameter.Comment: 13 pages, 5 figures, accepted for publication in A&
Understanding the impact of diet and nutrition on symptoms of Tourette Syndrome: A Scoping Review
This document is the accepted manuscript version. The final, definitive version of this paper has been published in Journal of Child Health Care, December 2017, published by SAGE Publishing, doi:https://doi.org/10.1177/1367493517748373.Anecdotal reports frequently suggest some dietary involvement in the maintenance of tics in children with Tourette syndrome (TS). This scoping review aimed to (1) understand the possible influence of diet as a trigger of tics and (2) map out the existing studies documenting dietary interventions in children with TS. Current evidence suggests no single diet to benefit individuals with TS. However, reports from parents of children with TS suggest that certain allergens in food may exacerbate tic-related symptoms. For example, an increase in tics has been related to the consumption of caffeine and refined sugar. Moreover, oligoantigenic diets and sugar-free diets have been identified as significantly reducing tics. More research is urgently needed to develop more accurate guidance for parents and children with TS, as many have reported using dietary and nutritional supplements, despite the lack of evidence detailing any benefits, side effects and recommended doses.Peer reviewedFinal Accepted Versio
Spectral and spatial imaging of the Be+sdO binary phi Persei
The rapidly rotating Be star phi Persei was spun up by mass and angular
momentum transfer from a now stripped-down, hot subdwarf companion. Here we
present the first high angular resolution images of phi Persei made possible by
new capabilities in longbaseline interferometry at near-IR and visible
wavelengths. We observed phi Persei with the MIRC and VEGA instruments of the
CHARA Array. Additional MIRC-only observations were performed to track the
orbital motion of the companion, and these were fit together with new and
existing radial velocity measurements of both stars to derive the complete
orbital elements and distance. The hot subdwarf companion is clearly detected
in the near-IR data at each epoch of observation with a flux contribution of
1.5% in the H band, and restricted fits indicate that its flux contribution
rises to 3.3% in the visible. A new binary orbital solution is determined by
combining the astrometric and radial velocity measurements. The derived stellar
masses are 9.6+-0.3Msol and 1.2+-0.2Msol for the Be primary and subdwarf
secondary, respectively. The inferred distance (186 +- 3 pc), kinematical
properties, and evolutionary state are consistent with membership of phi Persei
in the alpha Per cluster. From the cluster age we deduce significant
constraints on the initial masses and evolutionary mass transfer processes that
transformed the phi Persei binary system. The interferometric data place strong
constraints on the Be disk elongation, orientation, and kinematics, and the
disk angular momentum vector is coaligned with and has the same sense of
rotation as the orbital angular momentum vector. The VEGA visible continuum
data indicate an elongated shape for the Be star itself, due to the combined
effects of rapid rotation, partial obscuration of the photosphere by the
circumstellar disk, and flux from the bright inner disk.Comment: 16 pages, 6 figures, 1 Anne
LITpro: a model fitting software for optical interferometry
9 pagesInternational audienceLITpro is a software for fitting models on data obtained from various stellar optical interferometers, like the VLTI. As a baseline, for modeling the object, it provides a set of elementary geometrical and center-to-limb darkening functions, all combinable together. But it is also designed to make very easy the implementation of more specific models with their own parameters, to be able to use models closer to astrophysical considerations. So LITpro only requires the modeling functions to compute the Fourier transform of the object at given spatial frequencies, and wavelengths and time if needed. From this, LITpro computes all the necessary quantities as needed (e.g. visibilities, spectral energy distribution, partial derivatives of the model, map of the object model). The fitting engine, especially designed for this kind of optimization, is based on a modified Levenberg-Marquardt algorithm and has been successfully tested on real data in a prototype version. It includes a Trust Region Method, minimizing a heterogeneous non-linear and non-convex criterion and allows the user to set boundaries on free parameters. From a robust local minimization algorithm and a starting points strategy, a global optimization solution is effectively achieved. Tools have been developped to help users to find the global minimum. LITpro is also designed for performing fitting on heterogeneous data. It will be shown, on an example, how it fits simultaneously interferometric data and spectral energy distribution, with some benefits on the reliability of the solution and a better estimation of errors and correlations on the parameters. That is indeed necessary since present interferometric data are generally multi-wavelengths
- …