2,940 research outputs found
Clinical and magnetic resonance imaging features of idiopathic oculomotor neuropathy in 14 dogs: Canine Idiopathic Oculomotor Neuropathy
Ophthalmoplegia/ophthalmoparesis (internal, external, or both) has been reported in dogs secondary to neoplasia affecting the oculomotor nerve and is usually given a poor prognosis. The purpose of this retrospective study was to describe the clinical findings, magnetic resonance imaging (MRI) findings, management, outcome, and follow-up in a group of canine cases with idiopathic oculomotor neuropathy. Inclusion criteria included cases with ophthalmoplegia/ophthalmoparesis (internal, external or both) as sole neuroophthalmologic signs, complete ophthalmic and neurologic examination, head MRI, and a minimum follow-up period of 1 year. Dogs with progressive neurological signs not related to oculomotor neuropathy were excluded. Fourteen cases met the inclusion criteria. All cases were unilaterally affected. Magnetic resonance imaging showed equivocal enlargement of the oculomotor nerve in three cases, mild enlargement in five, and marked enlargement in six. Contrast enhancement was present in 12 cases, being marked in six. When present, the contrast enhancement was focal in eight cases and diffuse in four. The median follow-up time was 25 months. External ophthalmoparesis improved in seven cases, five cases under no treatment and two under systemic corticosteroid therapy. The clinical signs in the other seven cases remained unchanged. Idiopathic oculomotor neuropathy should be included as a differential diagnosis in dogs presenting with unilateral ophthalmoplegia/ophthalmoparesis (internal, external, or both) with the absence of other neurologic and ophthalmic signs, and with the MRI findings restricted to the oculomotor nerve. Idiopathic oculomotor neuropathy has a good prognosis as the clinical signs do not deteriorate and they can improve without treatment
Accuracy of stellar parameters of exoplanet-host stars determined from asteroseismology
In the context of the space-based mission CoRoT, devoted to asteroseismology
and search for planet transits, we analyse the accuracy of fundamental stellar
parameters (mass, radius, luminosity) that can be obtained from
asteroseismological data.} Our work is motivated by the large uncertainties on
planetary radius determination of transiting planets which are mainly due to
uncertainties on the stellar parameters. Our goal is to analyse uncertainties
of fundamental stellar parameters for a given accuracy of oscillation frequency
determination. We generate grids of equilibrium models of stars and compute
their pulsation spectra based on a linear nonadiabatic stability analysis.
Using differents methods of comparison of oscillation mode spectra, we derive
uncertainties on fundamental stellar parameters and analyse the effect of
varying the number of considered modes.} The limits obtained depend strongly on
the adapted method to compare spectra. We find a degeneracy in the stellar
parameter solutions, up to a few % in mass (from less than 1% to more than 7%
depending on the method used and the number of considered modes), luminosity
(from 2% to more than 10%) or radius (from less than 1% to 3%), for a given
pulsation spectrum.Comment: 7 pages, 9 figure
The Identity of Anthomyia melania Dufour, 1839 (Diptera: Fanniidae).
Anthomyia melania Dufour, 1839, und Homalomyia ciliata Stein, 1895, werden für Synonyme gehalten. Es erfolgt eine Redeskription dieser Art.Nomenklatorische Handlungenmelania (Dufour, 1839) (Fannia), Lectotype; comb. n. hitherto Anthomyia melaniaciliata Stein, 1895 (Homalomyia), syn. n. of Fannia melania (Dufour, 1839)Anthomyia melania Dufour, 1839, and Homalomyia ciliata Stein, 1895, are shown to be synonyms, and the species is redescribed.Nomenclatural Actsmelania (Dufour, 1839) (Fannia), Lectotype; comb. n. hitherto Anthomyia melaniaciliata Stein, 1895 (Homalomyia), syn. n. of Fannia melania (Dufour, 1839
A transiting planet among 23 new near-threshold candidates from the OGLE survey - OGLE-TR-182
By re-processing the data of the second season of the OGLE survey for
planetary transits and adding new mesurements on the same fields gathered in
subsequent years with the OGLE telescope, we have identified 23 new transit
candidates, recorded as OGLE-TR-178 to OGLE-TR-200. We studied the nature of
these objects with the FLAMES/UVES multi-fiber spectrograph on the VLT. One of
the candidates, OGLE-TR-182, was confirmed as a transiting gas giant planet on
a 4-day orbit. We characterised it with further observations using the FORS1
camera and UVES spectrograph on the VLT. OGLE-TR-182b is a typical ``hot
Jupiter'' with an orbital period of 3.98 days, a mass of 1.01 +- 0.15 MJup and
a radius of 1.13 (+0.24-0.08) RJup. Confirming this transiting planet required
a large investment in telescope time with the best instruments available, and
we comment on the difficulty of the confirmation process for transiting planets
in the OGLE survey. We delienate the zone were confirmation is difficult or
impossible, and discuss the implications for the Corot space mission in its
quest for transiting telluric planets.Comment: 7 pages, submitted to Astronomy and Astrophysic
Surface Brightness and Stellar Populations at the Outer Edge of the Large Magellanic Cloud: No Stellar Halo Yet
We present a high quality CMD for a 36'x 36' field located 8 degrees (7 kpc)
from the LMC center, as well as a precise determination of the LMC surface
brightness derived from the resolved stellar population out to this large
galactocentric radius. This deep CMD shows for the first time the detailed age
distribution at this position, where the surface brightness is V=26.5 mag/sq".
At a radius R=474' the main sequence is well populated from the oldest turnoff
at I=21.5 to the 2.5 Gyr turnoff at I=19.5. Beyond this radius, a relatively
strong gradient in the density of stars with ages in the 2.5-4 Gyr range is
apparent. There are some stars brighter and bluer than the main population,
quite uniformly distributed over the whole area surveyed, which are well
matched by a 1.5 Gyr isochrone and may be indicative of a relatively recent
star formation, or merger, event. The surface brightness profile of the LMC
remains exponential to this large galactocentric radius and shows no evidence
of disk truncation. Combining the information on surface brightness and stellar
population we conclude that the LMC disk extends (and dominates over a possible
stellar halo) out to a distance of at least 7 kpc. These results confirm that
the absence of blue stars in the relatively shallow off-center CMDs of dIrr
galaxies is not necessarily evidence for an exclusively old stellar population
resembling the halo of the Milky Way.Comment: ApJLett, in press 13 pages including 3 color figure
OGLE-TR-211 - a new transiting inflated hot Jupiter from the OGLE survey and ESO LP666 spectroscopic follow-up program
We present results of the photometric campaign for planetary and
low-luminosity object transits conducted by the OGLE survey in 2005 season
(Campaign #5). About twenty most promising candidates discovered in these data
were subsequently verified spectroscopically with the VLT/FLAMES spectrograph.
One of the candidates, OGLE-TR-211, reveals clear changes of radial velocity
with small amplitude of 82 m/sec, varying in phase with photometric transit
ephemeris. Thus, we confirm the planetary nature of the OGLE-TR-211 system.
Follow-up precise photometry of OGLE-TR-211 with VLT/FORS together with radial
velocity spectroscopy supplemented with high resolution, high S/N VLT/UVES
spectra allowed us to derive parameters of the planet and host star.
OGLE-TR-211b is a hot Jupiter orbiting a F7-8 spectral type dwarf star with the
period of 3.68 days. The mass of the planet is equal to 1.03+/-0.20 M_Jup while
its radius 1.36+0.18-0.09 R_Jup. The radius is about 20% larger than the
typical radius of hot Jupiters of similar mass. OGLE-TR-211b is, then, another
example of inflated hot Jupiters - a small group of seven exoplanets with large
radii and unusually small densities - objects being a challenge to the current
models of exoplanets.Comment: 6 pages. Submitted to Astronomy and Astrophysic
The `666' collaboration on OGLE transits: I. Accurate radius of the planets OGLE-TR-10b and OGLE-TR-56b with VLT deconvolution photometry
Transiting planets are essential to study the structure and evolution of
extra-solar planets. For that purpose, it is important to measure precisely the
radius of these planets. Here we report new high-accuracy photometry of the
transits of OGLE-TR-10 and OGLE-TR-56 with VLT/FORS1. One transit of each
object was covered in Bessel V and R filters, and treated with the
deconvolution-based photometry algorithm DECPHOT, to ensure accurate
millimagnitude light curves. Together with earlier spectroscopic measurements,
the data imply a radius of 1.22 +0.12-0.07 R_J for OGLE-TR-10b and 1.30 +- 0.05
R_J for OGLE-TR-56b. A re-analysis of the original OGLE photometry resolves an
earlier discrepancy about the radius of OGLE-TR-10. The transit of OGLE-TR-56
is almost grazing, so that small systematics in the photometry can cause large
changes in the derived radius. Our study confirms both planets as inflated hot
Jupiters, with large radii comparable to that of HD 209458 and at least two
other recently discovered transiting gas giants.Comment: Fundamental updates compared to previous version; accepted for
publication in Astronomy & Astrophysic
A phenomenological representation of iridescent colors in butterfly wings
The representation of the color of butterflies has always
been a challenge to artis
ts, whatever the medium
involved. These colors are highly complex to reproduce, even with the use of computer generated images. This
article introduces a new algorithm developed to simulate and generate the iridescent colors that are found on the
wings of particular butterflies. The model presented here
is based on the scientific description of the butterfly
Morpho menelaus
. Wing color is determined by interference, diffraction, absorption and reflection of light on
microscopic wing's structures. The color varies dependi
ng on a combination of the following parameters: view
angle, incidence and characteristics of the light source, and surrounding medium. This algorithm which tends to
real-time imaging required by computer graphics artis
ts still renders images with a fairly high degree of
accuracy
Houseflies of the Tristan da Cunha Islands: new records, including the first for Fannia albitarsis Stein, 1911 (Diptera: Fanniidae, Muscidae).
In der Arbeit werden historische und aktuelle Funde von Hausfliegen der Familien Fanniidae und Muscidae auf den Inseln der Tristan da Cunha-Gruppe im Südatlantik zusammengefaßt und diskutiert. Das aktuelle Material wurde 2005 auf den nördlichen Inseln, Tristan da Cunha und Nightingale, gesammelt. Insgesamt sind fünf Arten in vier Gattungen nachgewiesen, einschließlich der Erstnachweise von Fannia albitarsis Stein, 1911 innerhalb des Archipels und von Muscina stabulans (Fallén, 1817) auf der Insel Nightingale. Die korrekte taxonomische Einordnung von Coenosia trina Wiedemann, 1830 wird diskutiert. Auf die offensichtlich starke Verbreitung dieser Art und den möglichen negativen Einfluss auf die heimische Fauna wird ebenfalls hingewiesen.StichwörterDiptera, Muscidae, Fanniidae, Housefly, Lesser Housefly, Stable fly, Tristan da Cunha, Nightingale, Gough, Inaccessible, Island, South Atlantic.Information about the Fanniidae and Muscidae Houseflies of the south Atlantic island group of Tristan da Cunha, from the earliest records to the most recent findings, is presented and discussed. In total, five species belonging to four genera are recorded. This includes the finding for the first time of Fannia albitarsis Stein, 1911 in the archipelago and Muscina stabulans (Fallén, 1817) on Nightingale Island. Based on material collected in 2005 from the two northern islands, Tristan da Cunha and Nightingale, records and notes are given on four species. A discussion of the correct taxonomic rank of Coenosia trina Wiedemann, 1830 is given. The apparent proliferation of this species, and the possible implications that this may have on endemics, is noted.KeywordsDiptera, Muscidae, Fanniidae, Housefly, Lesser Housefly, Stable fly, Tristan da Cunha, Nightingale, Gough, Inaccessible, Island, South Atlantic
The spin-orbit angle of the transiting hot jupiter CoRoT-1b
We measure the angle between the planetary orbit and the stellar rotation
axis in the transiting planetary system CoRoT-1, with new HIRES/Keck and
FORS/VLT high-accuracy photometry. The data indicate a highly tilted system,
with a projected spin-orbit angle lambda = 77 +- 11 degrees. Systematic
uncertainties in the radial velocity data could cause the actual errors to be
larger by an unknown amount, and this result needs to be confirmed with further
high-accuracy spectroscopic transit measurements.
Spin-orbit alignment has now been measured in a dozen extra-solar planetary
systems, and several show strong misalignment. The first three misaligned
planets were all much more massive than Jupiter and followed eccentric orbits.
CoRoT-1, however, is a jovian-mass close-in planet on a circular orbit. If its
strong misalignment is confirmed, it would break this pattern. The high
occurence of misaligned systems for several types of planets and orbits favours
planet-planet scattering as a mechanism to bring gas giants on very close
orbits.Comment: to appear in in MNRAS letters [5 pages
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