7,064 research outputs found
Severe Cutaneous Dry Skin of Endocrine Origin - a Case Report
A xerose cutânea é um motivo frequente de consulta de dermatologia. O seu tratamento passa pela identificação da causa subjacente.
Os autores descrevem o caso clĂnico de um doente do sexo masculino, 49 anos, que recorre a consulta de dermatologia
por xerose cutânea severa com inĂcio há cerca de 4 meses. Referia tambĂ©m prurido intenso, xerose bucal e cansaço fácil. Dos antecedentes pessoais destacava-se tiroidectomia total há 8 meses, estando apenas medicado com cálcio, sem hormonas tiroideias. Ă€ apresentação, o doente tinha voz grave, edema palpebral, macroglossia,
xerose cutânea severa generalizada com áreas de eczema craquelé nos membros, hiperqueratose folicular dorsal,
hiperlinearidade das linhas das mãos, tonalidade cutânea palmoplantar amarelada e bradicárdia. Analiticamente, registava-se elevação das transaminases, hipercolesterolémia, hipertrigliceridémia, elevação da TSH e diminuição da T3 e T4. Salienta-se este caso pela semiologia rica de uma causa endocrinológica iatrogénica de xerose cutânea severa
ARES v2 - new features and improved performance
Aims: We present a new upgraded version of ARES. The new version includes a
series of interesting new features such as automatic radial velocity
correction, a fully automatic continuum determination, and an estimation of the
errors for the equivalent widths. Methods: The automatic correction of the
radial velocity is achieved with a simple cross-correlation function, and the
automatic continuum determination, as well as the estimation of the errors,
relies on a new approach to evaluating the spectral noise at the continuum
level. Results: ARES v2 is totally compatible with its predecessor. We show
that the fully automatic continuum determination is consistent with the
previous methods applied for this task. It also presents a significant
improvement on its performance thanks to the implementation of a parallel
computation using the OpenMP library.Comment: 4 pages, 2 Figures; accepted in A&A; ARES Webpage:
www.astro.up.pt/~sousasag/are
ARES+MOOG - a practical overview of an EW method to derive stellar parameters
The goal of this document is to describe the important practical aspects in
the use of an Equivalent Width (EW) method for the derivation of spectroscopic
stellar parameters. A general description of the fundamental steps composing
any EW method is given, together with possible differences that may be found in
different methods used in the literature. Then ARES+MOOG is then used as an
example where each step of the method is described in detail. A special focus
is given for the specific steps of this method, namely the use of a
differential analysis to define the atomic data for the adopted line list, the
automatic EW determinations, and the way to find the best parameters at the end
of the procedure. Finally, a practical tutorial is given, where we focus on
simple exercises useful to illustrate and explain the dependence of the
abundances with the assumed stellar parameters. The interdependences are
described and a clear procedure is given to find the "final" stellar
parameters.Comment: 15 pages, 4 figures, accepted for publication as a chapter in
"Determination of Atmospheric Parameters of B, A, F and G Type Stars",
Springer (2014), eds. E. Niemczura, B. Smalley, W. Pyc
TMCalc - A fast code to derive Teff and [Fe/H] for FGK stars
We present a new direct spectroscopic calibration for a fast estimation of
the stellar metallicity [Fe/H]. These calibrations were computed using a large
sample of 451 solar-type stars for which we have precise spectroscopic
parameters derived from high quality spectra. The new [Fe/H] calibration is
based on weak Fe I lines, which are expected to be less dependent on surface
gravity and microturbulence, and require only a pre-determination of the
effective temperature. This temperature can be obtained using a previously
presented line-ratio calibration. We also present a simple code that uses the
calibrations and procedures presented in these works to obtain both the
effective temperature and the [Fe/H] estimate. The code, written in C, is
freely available for the community and may be used as an extension of the ARES
code. We test these calibrations for 582 independent FGK stars. We show that
the code can be used as a precise and fast indicator of the spectroscopic
temperature and metallicity for dwarf FKG stars with effective temperatures
ranging from 4500 K to 6500 K and with [Fe/H] ranging from -0.8 dex to 0.4 dex.Comment: 10 pages, 8 Figures, published in A&
On the functional form of the metallicity-giant planet correlation
It is generally accepted that the presence of a giant planet is strongly
dependent on the stellar metallicity. A stellar mass dependence has also been
investigated, but this dependence does not seem as strong as the metallicity
dependence. Even for metallicity, however, the exact form of the correlation
has not been established. In this paper, we test several scenarios for
describing the frequency of giant planets as a function of its host parameters.
We perform this test on two volume-limited samples (from CORALIE and HARPS). By
using a Bayesian analysis, we quantitatively compared the different scenarios.
We confirm that giant planet frequency is indeed a function of metallicity.
However, there is no statistical difference between a constant or an
exponential function for stars with subsolar metallicities contrary to what has
been previously stated in the literature. The dependence on stellar mass could
neither be confirmed nor be discarded.Comment: 5 pages, 2 figures, accepted in A&
Leg Ulcers in Antiphospholipid Syndrome Secondary to Systemic Lupus Erythematosus Treated with Intravenous Immunoglobulin
BACKGROUND: Despite encouraging reports on the efficacy of intravenous immunoglobulin (IVIg) in antiphospholipid syndrome, the clinical value of this treatment is not well established, and most of the data are based on case reports and small series of patients.
OBSERVATION: We describe the significant improvement of leg ulcers with IVIg in a 61-year-old female, with diabetes mellitus, venous peripherical insufficiency and secondary antiphospholipid syndrome to systemic lupus erythematosus.
CONCLUSIONS: This case illustrates a rare cause of leg ulcers and documents that IVIg may be an effective adjuvant treatment in the management of selected patients with antiphospholipid syndrome when conventional strategies using subcutaneous heparin and low-dose aspirin are insufficient
Overabundance of alpha-elements in exoplanet host stars
We present the results for a chemical abundance analysis between
planet-hosting and stars without planets for 12 refractory elements for a total
of 1111 nearby FGK dwarf stars observed within the context of the HARPS GTO
programs. Of these stars, 109 are known to harbour high-mass planetary
companions and 26 stars are hosting exclusively Neptunians and super-Earths. We
found that the [X/Fe] ratios for Mg, Al, Si, Sc, and Ti both for giant and
low-mass planet hosts are systematically higher than those of comparison stars
at low metallicities ([Fe/H] < from -0.2 to 0.1 dex depending on the element).
The most evident discrepancy between planet-hosting and stars without planets
is observed for Mg. Our data suggest that the planet incidence is greater among
the thick disk population than among the thin disk for mettallicities bellow
-0.3 dex. After examining the [alpha/Fe] trends of the planet host and non-host
samples we conclude that a certain chemical composition, and not the Galactic
birth place of the stars, is the determinating factor for that. The inspection
of the Galactic orbital parameters and kinematics of the planet-hosting stars
shows that Neptunian hosts tend to belong to the "thicker" disk compared to
their high-mass planet-hosting counterparts.We also found that Neptunian hosts
follow the distribution of high-alpha stars in the UW vs V velocities space,
but they are more enhanced in Mg than high-alpha stars without planetary
companions. Our results indicate that some metals other than iron may also have
an important contribution to planet formation if the amount of iron is low.
These results may provide strong constraints for the models of planet
formation, especially for planets with low mass.Comment: 10 pages, 8 figures, 3 tables, accepted for publication in Astronomy
& Astrophysic
Chemical abundances of 1111 FGK stars from the HARPS GTO planet search program.Galactic stellar populations and planets
We performed a uniform and detailed abundance analysis of 12 refractory
elements (Na, Mg, Al, Si, Ca, Ti, Cr, Ni, Co, Sc, Mn and V) for a sample of
1111 FGK dwarf stars from the HARPS GTO planet search program. 109 of these
stars are known to harbour giant planetary companions and 26 stars are hosting
exclusively Neptunians and super-Earths. The main goals of this paper are i) to
investigate whether there are any differences between the elemental abundance
trends for stars of different stellar populations; ii) to characterise the
planet host and non-host samples in term of their [X/H]. The extensive study of
this sample, focused on the abundance differences between stars with and
without planets will be presented in a parallel paper. The equivalent widths of
spectral lines are automatically measured from HARPS spectra with the ARES
code. The abundances of the chemical elements are determined using a LTE
abundance analysis relative to the Sun, with the 2010 revised version of the
spectral synthesis code MOOG and a grid of Kurucz ATLAS9 atmospheres. To
separate the Galactic stellar populations we applied both a purely kinematical
approach and a chemical method. We found that the chemically separated (based
on the Mg, Si, and Ti abundances) thin and thick discs are also chemically
disjunct for Al, Sc, Co and Ca. Some bifurcation might also exist for Na, V,
Ni, and Mn, but there is no clear boundary of their [X/Fe] ratios. We confirm
that an overabundance in giant-planet host stars is clear for all the studied
elements.We also confirm that stars hosting only Neptunian-like planets may be
easier to detect around stars with similar metallicities as non-planet hosts,
although for some elements (particulary alpha-elements) the lower limit of
[X/H] are very abrupt.Comment: 14 pages, 12 figures, 6 tables. accepted for publication in Astronomy
& Astrophysic
- …