6,396 research outputs found
Instantaneous Three-dimensional Thermal Structure of the South Polar Vortex of Venus
The Venus thermal radiation spectrum exhibits the signature of
absorption bands. By means of inversion techniques, those bands enable the
retrieval of atmospheric temperature profiles. We have analyzed VIRTIS-M-IR
night-side data obtaining high-resolution thermal maps of Venus south polar
region between 55 and 85 km altitudes for three dynamical configurations of the
vortex. The cold collar is clearly distinguishable at km altitude
level, and it is more than 15 K colder than the pole on average. The South
Polar Vortex appears as a vertically extended hot region close to the pole and
squeezed by the cold collar between altitudes 55 and 67 km but spreading
equatorward at about 74 km. Both the instantaneous temperature maps and their
zonal averages show that the top altitude limit of the thermal signature of the
vortex is at km altitude, at least on the night-side of the planet.
The upper part of the atmosphere (67 - 85 km) is more homogeneous and has
long-scale horizontal temperature differences of about 25 K over horizontal
distances of km. The lower part (55 - 67 km) shows more fine-scale
structure, creating the vortex' morphology, with thermal differences of up to
about 50 K over km horizontal distances. We also study the vertical
stability of different atmospheric layers within the 55 - 85 km altitude range
for the three vortex configurations. It is always positive, but the cold collar
is the most vertically stable structure at polar latitudes, while the vortex
and sub-polar latitudes show lower stability values. Furthermore, the hot
filaments present within the vortex exhibit lower stability values than their
surroundings. The layer between 62 and 67 km resulted to be the most stable.
These results are in good agreement with conclusions from previous radio
occultation analyses
The Role of IL-33 in Host Response to Candida albicans
Background. Interleukin (IL) 33 is a recently identified pleiotropic cytokine that influences the activity of multiple cell types and orchestrates complex innate and adaptive immune responses. Methods. We performed an extensive review of the literature published between 2005 and 2013 on IL-33 and related cytokines, their functions, and their regulation of the immune system following Candida albicans colonization. Our literature review included cross-references from retrieved articles and specific data from our own studies. Results. IL-33 (IL-1F11) is a recently identified member of the IL-1 family of cytokines. Accumulating evidence suggests a pivotal role of the IL-33/ST2 axis in host immune defense against fungal pathogens, including C. albicans. IL-33 induces a Th2-type inflammatory response and activates both innate and adaptive immunity. Studies in animal models have shown that Th2 inflammatory responses have a beneficial role in immunity against gastrointestinal and systemic infections by Candida spp. Conclusions. This review summarizes the most important clinical studies and case reports describing the beneficial role of IL-33 in immunity and host defense mechanisms against pathogenic fungi. The finding that the IL-33/ST2 axis is involved in therapeutic target has implications for the prevention and treatment of inflammatory diseases, including acute or chronic candidiasis
A study of central galaxy rotation with stellar mass and environment
© 2017. The American Astronomical Society. All rights reserved. We present a pilot analysis of the influence of galaxy stellar mass and cluster environment on the probability of slow rotation in 22 central galaxies at mean redshift z = 0.07. This includes new integral-field observations of five central galaxies selected from the Sloan Digital Sky Survey, observed with the SPIRAL integral-field spectrograph on the Anglo-Australian Telescope. The composite sample presented here spans a wide range of stellar masses, 10.9 < log(M∗/M⊙)lt; 12.0, and are embedded in halos ranging from groups to clusters, 12.9 < log(M 200 Ṁ) < 15.6. We find a mean probability of slow rotation in our sample of P(SR) = 54 ± 7%. Our results show an increasing probability of slow rotation in central galaxies with increasing stellar mass. However, when we examine the dependence of slow rotation on host cluster halo mass, we do not see a significant relationship. We also explore the influence of cluster dominance on slow rotation in central galaxies. Clusters with low dominance are associated with dynamically younger systems. We find that cluster dominance has no significant effect on the probability of slow rotation in central galaxies. These results conflict with a paradigm in which halo mass alone predetermines central galaxy properties
A chaotic long-lived vortex at Venus southern pole
Polar vortices are common in the atmospheres of rapidly rotating planets
[1-4]. On Earth and Mars they are tied to the surface and their existence
follows the seasonal insolation cycle [1-3]. Venus is a slowly rotating planet
but it is also known to have vortices at both poles at the edge of a
superrotating atmosphere [5-8]. However, their nature and long-term properties
have not been constrained so far impeding precise modeling. Here we report
cloud motions at two altitude levels (about 42 km and 63 km above the surface)
using infrared images from the VIRTIS instrument onboard Venus Express that
show that the south polar vortex is a permanent but erratic and unpredictable
feature. We find that the centers of rotation of the vortex at these levels
rarely coincide and both wander erratically around the pole with speeds of up
to 16 m s-1. The cloud morphology and vorticity patches are uncorrelated and
change continuously developing transient areas of small vertical motions. Venus
south polar vortex is a continuously evolving structure immersed in a
baroclinic environment laying at altitude levels that have variable vertical
and meridional wind shears, extending at least 20 km in height through a
quasi-convective turbulent region
Mirror matter admixtures and isospin breaking in the \Delta I=1/2 rule in \Omega^- two body non-leptonic decays
We discuss a description of \Omega^- two body non-leptonic decays based on
possible, albeit tiny, admixtures of mirror matter in ordinary hadrons. The
\Delta I=1/2 rule enhancement is obtained as a result of isospin symmetry and,
more importantly, the rather large observed deviations from this rule result
from small isospin breaking. This analysis lends support to the possibility
that the enhancement phenomenon observed in low energy weak interactions may be
systematically described by mirror matter admixtures in ordinary hadrons.Comment: Changed conten
Minimax Current Density Coil Design
'Coil design' is an inverse problem in which arrangements of wire are
designed to generate a prescribed magnetic field when energized with electric
current. The design of gradient and shim coils for magnetic resonance imaging
(MRI) are important examples of coil design. The magnetic fields that these
coils generate are usually required to be both strong and accurate. Other
electromagnetic properties of the coils, such as inductance, may be considered
in the design process, which becomes an optimization problem. The maximum
current density is additionally optimized in this work and the resultant coils
are investigated for performance and practicality. Coils with minimax current
density were found to exhibit maximally spread wires and may help disperse
localized regions of Joule heating. They also produce the highest possible
magnetic field strength per unit current for any given surface and wire size.
Three different flavours of boundary element method that employ different basis
functions (triangular elements with uniform current, cylindrical elements with
sinusoidal current and conic section elements with sinusoidal-uniform current)
were used with this approach to illustrate its generality.Comment: 24 pages, 6 figures, 2 tables. To appear in Journal of Physics D:
Applied Physic
Imprints of galaxy evolution on H ii regions Memory of the past uncovered by the CALIFA survey
H ii regions in galaxies are the sites of star formation and thus particular
places to understand the build-up of stellar mass in the universe. The line
ratios of this ionized gas are frequently used to characterize the ionization
conditions. We use the Hii regions catalogue from the CALIFA survey (~5000 H ii
regions), to explore their distribution across the classical [OIII]/Hbeta vs.
[NII]/Halpha diagnostic diagram, and how it depends on the oxygen abundance,
ionization parameter, electron density, and dust attenuation. We compared the
line ratios with predictions from photoionization models. Finally, we explore
the dependences on the properties of the host galaxies, the location within
those galaxies and the properties of the underlying stellar population. We
found that the location within the BPT diagrams is not totally predicted by
photoionization models. Indeed, it depends on the properties of the host
galaxies, their galactocentric distances and the properties of the underlying
stellar population. These results indicate that although H ii regions are short
lived events, they are affected by the total underlying stellar population. One
may say that H ii regions keep a memory of the stellar evolution and chemical
enrichment that have left an imprint on the both the ionizing stellar
population and the ionized gasComment: 18 pages, 8 figures, accepted for publishing in A&
A randomized phase II trial of platinum salts in basal-like breast cancer patients in the neoadjuvant setting. Results from the GEICAM/2006-03, multicenter study
Este artículo ha sido publicado en Breast Cancer Research and Treatment
Siguiendo las instruciones y dado que la revista dice que el artículo fue publicado tal cual se envió, hacemos un postprint copiando dicho texto enviado por la revista en un documento Word y luego convertido a PDF para así respetar el contenido, y sin dar acceso a los "extras" de la versión publicada.
Esta versión tiene Licencia Creative Commons CC-BY-NC-NDAbstract Chemotherapy remains as the only systemic treatment option available for basal-like breast cancer (BC) patients. Preclinical models and several phase II studies suggested that platinum salts are active drugs in this BC subtype though there is no randomized study supporting this hypothesis. This study investigates if the addition of carboplatin to a combination of an alkylating agent together with anthracyclines and taxanes is able to increase the efficacy in the neoadjuvant treatment context. Patients with operable breast cancer and immunophenotypically defined basal-like disease (ER-/PR-/HER2- and cytokeratin 5/6?
or EGFR?) were recruited. Patients were randomized to receive EC (epirubicin 90 mg/m2 plus cyclophosphamide
600 mg/m2 for 4 cycles) followed either by D (docetaxel 100 mg/m2 9 4 cycles; EC–D) or DCb (docetaxel 75 mg/
m2 plus carboplatin AUC 6 9 4 cycles; EC–DCb). The primary end point was pathological complete response
(pCR) in the breast following the Miller and Payne criteria. Ninety-four patients were randomized (46 EC–D, 48 EC–
DCb). pCR rate in the breast was seen in 16 patients (35 %) with EC–D and 14 patients (30 %) with EC–DCb
(P value = 0.61). pCR in the breast and axilla was seen in 30 % of patients in both arms. The overall clinical response
rate was 70 % (95 % CI 56–83) in the EC–D arm and 77 % (95 % CI 65–87) in the EC–DCb arm. Grade 3/4 toxicity
was similar in both arms. The addition of carboplatin to conventional chemotherapy with EC–D in basal-like breast
cancer patients did not improve the efficacy probably because they had already received an alkylating agent.
These findings should be taken into consideration when developing new agents for this disease.This trial was partially supported by Pfizer S.L.U
The Mass-Metallicity relation explored with CALIFA: I. Is there a dependence on the star formation rate?
We present the results on the study of the global and local M-Z relation
based on the first data available from the CALIFA survey (150 galaxies). This
survey provides integral field spectroscopy of the complete optical extent of
each galaxy (up to 2-3 effective radii), with enough resolution to separate
individual HII regions and/or aggregations. Nearly 3000 individual HII
regions have been detected. The spectra cover the wavelength range between
[OII]3727 and [SII]6731, with a sufficient signal-to-noise to derive the oxygen
abundance and star-formation rate associated with each region. In addition, we
have computed the integrated and spatially resolved stellar masses (and surface
densities), based on SDSS photometric data. We explore the relations between
the stellar mass, oxygen abundance and star-formation rate using this dataset.
We derive a tight relation between the integrated stellar mass and the
gas-phase abundance, with a dispersion smaller than the one already reported in
the literature (0.07 dex). Indeed, this
dispersion is only slightly larger than the typical error derived for our
oxygen abundances. However, we do not find any secondary relation with the
star-formation rate, other than the one induced due to the primary relation of
this quantity with the stellar mass. We confirm the result using the 3000
individual HII regions, for the corresponding local relations.
Our results agree with the scenario in which gas recycling in galaxies, both
locally and globally, is much faster than other typical timescales, like that
of gas accretion by inflow and/or metal loss due to outflows. In essence,
late-type/disk dominated galaxies seem to be in a quasi-steady situation, with
a behavior similar to the one expected from an instantaneous
recycling/closed-box model.Comment: 19 Pages, 8 figures, Accepted for Publishing in Astronomy and
Astrophysics (A&A
Analysis of Fine Motor Skills in Essential Tremor: Combining Neuroimaging and Handwriting Biomarkers for Early Management
Essential tremor (ET) is a highly prevalent neurological disorder characterized by action-induced tremors involving the hand, voice, head, and/or face. Importantly, hand tremor is present in nearly all forms of ET, resulting in impaired fine motor skills and diminished quality of life. To advance early diagnostic approaches for ET, automated handwriting tasks and magnetic resonance imaging (MRI) offer an opportunity to develop early essential clinical biomarkers. In this study, we present a novel approach for the early clinical diagnosis and monitoring of ET based on integrating handwriting and neuroimaging analysis. We demonstrate how the analysis of fine motor skills, as measured by an automated Archimedes’ spiral task, is correlated with neuroimaging biomarkers for ET. Together, we present a novel modeling approach that can serve as a complementary and promising support tool for the clinical diagnosis of ET and a large range of tremors.This work was supported in part by the Universidad del País Vasco/Euskal Herriko Unibertsitatea, the University of Cambridge, PPG 17/51 and GIU 092/19, the Basque government (Saiotek SA-2010/00028, ELEKIN, Engineering and Society and Bioengineering Research Groups, GIC18/136, and ELKARTEK 18/99, 20/81), ‘‘Ministerio de Ciencia e Innovación’’ (SAF201677758R), FEDER funds, DomusVi Foundation (FP18/76), and the government of Gipuzkoa (HELENA, SABRINA, DG18/14-23, DG19/29, DG20/25 projects). This work is also based upon the work from COST Actions CA18106 and CA15225, supported by COST (European Cooperation in Science and Technology)
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