3,780 research outputs found
Síndrome de Frey – Uma visão global do tema
ResumoIntroduçãoO Síndrome de Frey resulta de uma lesão irritativa ou mecânica das fibras vegetativas do nervo auriculotemporal. Esta lesão provoca uma regeneração aberrante das fibras parassimpáticas pós-ganglionares para os recetores das glândulas sudoríparas e vasos sanguíneos, provocando aumento da sensibilidade, eritema cutâneo e sudação durante a mastigação de alimentos.MétodosEste trabalho foi realizado com base numa pesquisa bibliográfica realizada na base de dados PubMed, utilizando a combinação de palavras (mesh terms): «Frey's syndrome» or «Auriculotemporal syndrome» or «Gustatory sweating».ResultadosNo total foram encontrados 262 artigos que foram publicados no período compreendido entre 1974-2012. Após a leitura dos resumos de cada artigo estes foram selecionados e categorizados a fim de facilitar a análise dos mesmos e excluir os menos relevantes para o estudo. Esta categorização permitiu atingir os objetivos deste trabalho que consistem em apresentar os aspetos principais relativos à Síndrome de Frey, nomeadamente a sua neuroanatomia, fisiopatologia, incidência, etiologia, diagnóstico, prevenção e tratamento.Conclusão Dos doentes submetidos a parotidectomia, apenas uma pequena percentagem apresenta queixas espontâneas sugestivas deste síndrome. Deste modo, o uso rotineiro de procedimentos preventivos deve ser considerado e devidamente ponderado, uma vez que poderão mascarar possíveis recidivas tumorais a longo prazo. Por outro lado, a primeira opção de tratamento continua a ser a injeção de toxina botulínica tipo A.AbstractIntroductionFrey's syndrome is caused by a mechanical irritative lesion of the vegetative fibers from the auriculotemporal nerve. This lesion causes an abnormal regeneration of the post-ganglionic parasympathetic fibers to the receptors sweat gland and blood vessels, causing increases sensitivity, skin erythema and sudation during meals.MethodsA literature search was performed in PubMed, using a combination of words (Mesh terms), such as «Frey's syndrome» or «syndrome Auriculotemporal» or «gustatory sweating».Results262 articles, published between 1974 and 2012, were found. Papers were selected and categorized into several groups after reading their abstracts, to facilitate their analysis and exclude the less relevant to the study. This selection led to the achievement of the objectives of this paper, presenting the most relevant aspects of Frey's syndrome, including neuroanatomy, physiopathology, incidence, etiology, diagnosis, prevention and treatment.ConclusionAmong the patients who had parotidectomies only a few mentioned spontaneously symptoms suggestive of Frey's syndrome. Therefore the routine use of preventive procedures must be previously and thoroughly considered since it may mask tumoral relapse in the long term. When treatment is needed, the first choice is, still, the injection of botulinum toxin type A
Resolving galaxies in time and space: II: Uncertainties in the spectral synthesis of datacubes
In a companion paper we have presented many products derived from the
application of the spectral synthesis code STARLIGHT to datacubes from the
CALIFA survey, including 2D maps of stellar population properties and 1D
averages in the temporal and spatial dimensions. Here we evaluate the
uncertainties in these products. Uncertainties due to noise and spectral shape
calibration errors and to the synthesis method are investigated by means of a
suite of simulations based on 1638 CALIFA spectra for NGC 2916, with
perturbations amplitudes gauged in terms of the expected errors. A separate
study was conducted to assess uncertainties related to the choice of
evolutionary synthesis models. We compare results obtained with the Bruzual &
Charlot models, a preliminary update of them, and a combination of spectra
derived from the Granada and MILES models. About 100k CALIFA spectra are used
in this comparison.
Noise and shape-related errors at the level expected for CALIFA propagate to
0.10-0.15 dex uncertainties in stellar masses, mean ages and metallicities.
Uncertainties in A_V increase from 0.06 mag in the case of random noise to 0.16
mag for shape errors. Higher order products such as SFHs are more uncertain,
but still relatively stable. Due to the large number statistics of datacubes,
spatial averaging reduces uncertainties while preserving information on the
history and structure of stellar populations. Radial profiles of global
properties, as well as SFHs averaged over different regions are much more
stable than for individual spaxels. Uncertainties related to the choice of base
models are larger than those associated with data and method. Differences in
mean age, mass and metallicity are ~ 0.15 to 0.25 dex, and 0.1 mag in A_V.
Spectral residuals are ~ 1% on average, but with systematic features of up to
4%. The origin of these features is discussed. (Abridged)Comment: A&A, accepte
The decay Z -> neutrino antineutrino photon in the Standard Model
A complete study of the one-loop induced decay Z -> neutrino antineutrino
photon is presented within the framework of the Standard Model. The advantages
of using a nonlinear gauge are stressed. We have found that the main
contributions come from the electric dipole and the magnetic dipole transitions
of the Z gauge boson and the neutrino, respectively. We obtain a branching
ratio B=7.16E-10, which is about four orders of magnitude smaller than the
bound recentely obtained by the L3 collaboration and thus it leaves open a
window to search for new physics effects in single-photon decays of the Z
boson.Comment: REVTEX,15 pp, 5 eps figures, Approved for publication in Physical
Review
The effects of spatial resolution on Integral Field Spectrograph surveys at different redshifts. The CALIFA perspective
Over the past decade, 3D optical spectroscopy has become the preferred tool
for understanding the properties of galaxies and is now increasingly used to
carry out galaxy surveys. Low redshift surveys include SAURON, DiskMass,
ATLAS3D, PINGS and VENGA. At redshifts above 0.7, surveys such as MASSIV, SINS,
GLACE, and IMAGES have targeted the most luminous galaxies to study mainly
their kinematic properties. The on-going CALIFA survey () is the
first of a series of upcoming Integral Field Spectroscopy (IFS) surveys with
large samples representative of the entire population of galaxies. Others
include SAMI and MaNGA at lower redshift and the upcoming KMOS surveys at
higher redshift. Given the importance of spatial scales in IFS surveys, the
study of the effects of spatial resolution on the recovered parameters becomes
important. We explore the capability of the CALIFA survey and a hypothetical
higher redshift survey to reproduce the properties of a sample of objects
observed with better spatial resolution at lower redshift. Using a sample of
PINGS galaxies, we simulate observations at different redshifts. We then study
the behaviour of different parameters as the spatial resolution degrades with
increasing redshift.Comment: 20 pages, 16 figures. Accepted for publication in A&
Ionized gas kinematics of galaxies in the CALIFA survey I: Velocity fields, kinematic parameters of the dominant component, and presence of kinematically distinct gaseous systems
This work provides an overall characterization of the kinematic behavior of
the ionized gas of the galaxies included in the Calar Alto Legacy Integral
field Area (CALIFA), offering kinematic clues to potential users of this survey
for including kinematical criteria for specific studies. From the first 200
galaxies observed by CALIFA, we present the 2D kinematic view of the 177
galaxies satisfying a gas detection threshold. After removing the stellar
contribution, we used the cross-correlation technique to obtain the radial
velocity of the dominant gaseous component. The main kinematic parameters were
directly derived from the radial velocities with no assumptions on the internal
motions. Evidence of the presence of several gaseous components with different
kinematics were detected by using [OIII] profiles. Most objects in the sample
show regular velocity fields, although the ionized-gas kinematics are rarely
consistent with simple coplanar circular motions. 35% of the objects present
evidence of a displacement between the photometric and kinematic centers larger
than the original spaxel radii. Only 17% of the objects in the sample exhibit
kinematic lopsidedness when comparing receding and approaching sides of the
velocity fields, but most of them are interacting galaxies exhibiting nuclear
activity. Early-type galaxies in the sample present clear photometric-kinematic
misaligments. There is evidence of asymmetries in the emission line profiles
suggesting the presence of kinematically distinct gaseous components at
different distances from the nucleus. This work constitutes the first
determination of the ionized gas kinematics of the galaxies observed in the
CALIFA survey. The derived velocity fields, the reported kinematic
peculiarities and the identification of the presence of several gaseous
components might be used as additional criteria for selecting galaxies for
specific studies.Comment: 38 pages, 16 figures, 4 tables. Paper accepted for publication in A&
Very light CP-odd scalar in the Two-Higgs-Doublet Model
We show that a general two-Higgs-doublet model (THDM) with a very light
CP-odd scalar (A) can be compatible with the rho parameter, Br(b --> s\gamma),
R_b, A_b, (g-2) of muon, Br(Upsilon --> A gamma), and the direct search via the
Yukawa process at LEP. For its mass around 0.2 GeV, the muon (g-2) and
Br(Upsilon --> A \gamma) data require tan(beta) to be about 1. Consequently, A
can behave like a fermiophobic CP-odd scalar and predominantly decay into a
photon pair ("gamma gamma"), which registers in detectors of high energy
collider experiments as a single photon signature when the momentum of A is
large. We compute the partial decay width of Z --> A A A and the production
rate of f \bar{f} --> Z A A --> Z +"gamma gamma", f^' {\bar f} --> W^{\pm} A A
--> W^\pm + "gamma gamma" and f \bar f --> H^+ H^- --> W^+ W^- A A --> W^+ W^-
+ "gamma gamma" at high energy colliders such as LEP, Tevatron, LHC, and future
Linear Colliders. Other production mechanisms of a light A, such as gg --> h
--> AA --> "gamma gamma", are also discussed.Comment: Some improvementes, references updated, 3 new figures, one new
appendix, abstract and conclusions unchaged. Version to appear in Physical
Review
CALIFA, the Calar Alto Legacy Integral Field Area survey: I. Survey presentation
We present here the Calar Alto Legacy Integral Field Area (CALIFA) survey,
which has been designed to provide a first step in this direction.We summarize
the survey goals and design, including sample selection and observational
strategy.We also showcase the data taken during the first observing runs
(June/July 2010) and outline the reduction pipeline, quality control schemes
and general characteristics of the reduced data. This survey is obtaining
spatially resolved spectroscopic information of a diameter selected sample of
galaxies in the Local Universe (0.005< z <0.03). CALIFA has been
designed to allow the building of two-dimensional maps of the following
quantities: (a) stellar populations: ages and metallicities; (b) ionized gas:
distribution, excitation mechanism and chemical abundances; and (c) kinematic
properties: both from stellar and ionized gas components. CALIFA uses the PPAK
Integral Field Unit (IFU), with a hexagonal field-of-view of
\sim1.3\sq\arcmin', with a 100% covering factor by adopting a three-pointing
dithering scheme. The optical wavelength range is covered from 3700 to 7000
{\AA}, using two overlapping setups (V500 and V1200), with different
resolutions: R\sim850 and R\sim1650, respectively. CALIFA is a legacy survey,
intended for the community. The reduced data will be released, once the quality
has been guaranteed. The analyzed data fulfill the expectations of the original
observing proposal, on the basis of a set of quality checks and exploratory
analysis.
We conclude from this first look at the data that CALIFA will be an important
resource for archaeological studies of galaxies in the Local Universe.Comment: 32 pages, 29 figures, Accepted for publishing in Astronomy and
Astrophysic
The Pierre Auger Observatory III: Other Astrophysical Observations
Astrophysical observations of ultra-high-energy cosmic rays with the Pierre
Auger ObservatoryComment: Contributions to the 32nd International Cosmic Ray Conference,
Beijing, China, August 201
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