192 research outputs found
GATA-1 as a Regulator of Mast Cell Differentiation Revealed by the Phenotype of the GATA-1low Mouse Mutant
Here it is shown that the phenotype of adult mice lacking the first enhancer (DNA hypersensitive site I) and the distal promoter of the GATA-1 gene (neoÎHS or GATA-1low mutants) reveals defects in mast cell development. These include the presence of morphologically abnormal alcian blue+ mast cells and apoptotic metachromaticâ mast cell precursors in connective tissues and peritoneal lavage and numerous (60â70% of all the progenitors) âuniqueâ trilineage cells committed to erythroid, megakaryocytic, and mast pathways in the bone marrow and spleen. These abnormalities, which were mirrored by impaired mast differentiation in vitro, were reversed by retroviral-mediated expression of GATA-1 cDNA. These data indicate an essential role for GATA-1 in mast cell differentiation
On the Possibility of a Microwave Approach for Rooms and Objects Sterilization
It is well known that the heat is an enemy of both virus and microbes. Starting from this consideration we discuss the possibility of using a microwave approach for a safe and cheap sterilization of closed rooms
Os retratos de Maria Isabel e Maria Francisca de Bragança, de Nicolas-Antoine Taunay
Nicolas-Antoine Taunay, French landscape painter, produced also several portraits during his stay at the Rio de Janeiro Court. In this city, in 1816, he paints the queen Carlota Joaquina and all her daughters. In this group, two portraits have a very special way: the paintings still today catalogued as Maria Francisca and Maria Teresa, but probably being Maria Isabel and Maria Francisca de Assis - princesses that, in this year, left Brazil to marry the Spanish King Fernando VII, and his brother Carlos Maria Isidro de Bourbon. In this article, beyond to describe these portraits (and analyse the identities of the portrayed princesses), I analyse their functions in the Court society and the mains artists of this gender in Europe. I will discuss, as well, the hypothesis about the Taunay choices. In this sense, I will analyse the possible circulation of the typologies of portrait between Italy, Portugal, Spain and France, understanding these productions by Taunay and the functions occupied by these portraits in the political relations between Brazil and Europe.Nicolas-Antoine Taunay, pintor de paisagens francĂȘs, tambĂ©m realizou alguns retratos durante sua estadia na corte do Rio de Janeiro. Nessa cidade, em 1816, ele pinta a rainha Carlota Joaquina e todas as suas filhas. Nesse conjunto, dois retratos sobressaem-se de modo especial: os hoje ainda inventariados como de Maria Francisca e de Maria Teresa, mas que provavelmente sĂŁo o de Maria Isabel e o de Maria Francisca de Assis - princesas que, nesse ano, deixavam o Brasil para casar-se, respectivamente, com Fernando VII, o rei espanhol, e com seu irmĂŁo Carlos Isidro de Bourbon. Neste artigo, alĂ©m de descrevermos os retratos (e analisarmos a questĂŁo da identidade das princesas retratadas), abordamos suas funçÔes na sociedade das cortes e os principais artistas do gĂȘnero na Europa. Discutimos, tambĂ©m, as hipĂłteses que permeiam as escolhas de Taunay para sua execução. Nesse sentido, tratamos da possĂvel circulação de tipologias entre ItĂĄlia, Portugal, Espanha e França, buscando entender a forma como Taunay os realizou e as funçÔes que doravante tais retratos ocupariam nas relaçÔes entre o Brasil e a Europa.Universidade Federal de SĂŁo Paulo (UNIFESP)UNIFESPSciEL
Euclid preparation XXXIV. The effect of linear redshift-space distortions in photometric galaxy clustering and its cross-correlation with cosmic shear
Context. The cosmological surveys that are planned for the current decade will provide us with unparalleled observations of the distribution of galaxies on cosmic scales, by means of which we can probe the underlying large-scale structure (LSS) of the Universe. This will allow us to test the concordance cosmological model and its extensions. However, precision pushes us to high levels of accuracy in the theoretical modelling of the LSS observables, so that no biases are introduced into the estimation of the cosmological parameters. In particular, effects such as redshift-space distortions (RSD) can become relevant in the computation of harmonic-space power spectra even for the clustering of the photometrically selected galaxies, as has previously been shown in literature.
Aims. In this work, we investigate the contribution of linear RSD, as formulated in the Limber approximation by a previous work, in forecast cosmological analyses with the photometric galaxy sample of the Euclid survey. We aim to assess their impact and to quantify the bias on the measurement of cosmological parameters that would be caused if this effect were neglected.
Methods. We performed this task by producing mock power spectra for photometric galaxy clustering and weak lensing, as is expected to be obtained from the Euclid survey. We then used a Markov chain Monte Carlo approach to obtain the posterior distributions of cosmological parameters from these simulated observations.
Results. When the linear RSD is neglected, significant biases are caused when galaxy correlations are used alone and when they are combined with cosmic shear in the so-called 3 Ă 2 pt approach. These biases can be equivalent to as much as 5Ï when an underlying ÎCDM cosmology is assumed. When the cosmological model is extended to include the equation-of-state parameters of dark energy, the extension parameters can be shifted by more than 1Ï
Euclid preparation TBD. The effect of baryons on the Halo Mass Function
The Euclid photometric survey of galaxy clusters stands as a powerful
cosmological tool, with the capacity to significantly propel our understanding
of the Universe. Despite being sub-dominant to dark matter and dark energy, the
baryonic component in our Universe holds substantial influence over the
structure and mass of galaxy clusters. This paper presents a novel model to
precisely quantify the impact of baryons on galaxy cluster virial halo masses,
using the baryon fraction within a cluster as proxy for their effect.
Constructed on the premise of quasi-adiabaticity, the model includes two
parameters calibrated using non-radiative cosmological hydrodynamical
simulations and a single large-scale simulation from the Magneticum set, which
includes the physical processes driving galaxy formation. As a main result of
our analysis, we demonstrate that this model delivers a remarkable one percent
relative accuracy in determining the virial dark matter-only equivalent mass of
galaxy clusters, starting from the corresponding total cluster mass and baryon
fraction measured in hydrodynamical simulations. Furthermore, we demonstrate
that this result is robust against changes in cosmological parameters and
against varying the numerical implementation of the sub-resolution physical
processes included in the simulations. Our work substantiates previous claims
about the impact of baryons on cluster cosmology studies. In particular, we
show how neglecting these effects would lead to biased cosmological constraints
for a Euclid-like cluster abundance analysis. Importantly, we demonstrate that
uncertainties associated with our model, arising from baryonic corrections to
cluster masses, are sub-dominant when compared to the precision with which
mass-observable relations will be calibrated using Euclid, as well as our
current understanding of the baryon fraction within galaxy clusters.Comment: 18 pages, 10 figures, 4 tables, 1 appendix, abstract abridged for
arXiv submissio
Euclid preparation. TBD. Forecast impact of super-sample covariance on 3x2pt analysis with Euclid
Deviations from Gaussianity in the distribution of the fields probed by
large-scale structure surveys generate additional terms in the data covariance
matrix, increasing the uncertainties in the measurement of the cosmological
parameters. Super-sample covariance (SSC) is among the largest of these
non-Gaussian contributions, with the potential to significantly degrade
constraints on some of the parameters of the cosmological model under study --
especially for weak lensing cosmic shear. We compute and validate the impact of
SSC on the forecast uncertainties on the cosmological parameters for the Euclid
photometric survey, obtained with a Fisher matrix analysis, both considering
the Gaussian covariance alone and adding the SSC term -- computed through the
public code PySSC. The photometric probes are considered in isolation and
combined in the `32pt' analysis. We find the SSC impact to be
non-negligible -- halving the Figure of Merit of the dark energy parameters
(, ) in the 32pt case and substantially increasing the
uncertainties on , and for cosmic shear;
photometric galaxy clustering, on the other hand, is less affected due to the
lower probe response. The relative impact of SSC does not show significant
changes under variations of the redshift binning scheme, while it is smaller
for weak lensing when marginalising over the multiplicative shear bias nuisance
parameters, which also leads to poorer constraints on the cosmological
parameters. Finally, we explore how the use of prior information on the shear
and galaxy bias changes the SSC impact. Improving shear bias priors does not
have a significant impact, while galaxy bias must be calibrated to sub-percent
level to increase the Figure of Merit by the large amount needed to achieve the
value when SSC is not included.Comment: 22 pages, 13 figure
Euclid preparation. Spectroscopy of active galactic nuclei with NISP
The statistical distribution and evolution of key properties (e.g. accretion
rate, mass, or spin) of active galactic nuclei (AGN), remain an open debate in
astrophysics. The ESA Euclid space mission, launched on July 1st 2023, promises
a breakthrough in this field. We create detailed mock catalogues of AGN
spectra, from the rest-frame near-infrared down to the ultraviolet, including
emission lines, to simulate what Euclid will observe for both obscured (type 2)
and unobscured (type 1) AGN. We concentrate on the red grisms of the NISP
instrument, which will be used for the wide-field survey, opening a new window
for spectroscopic AGN studies in the near-infrared. We quantify the efficiency
in the redshift determination as well as in retrieving the emission line flux
of the H+[NII] complex as Euclid is mainly focused on this emission
line as it is expected to be the brightest one in the probed redshift range.
Spectroscopic redshifts are measured for 83% of the simulated AGN in the
interval where the H+[NII] is visible (0.89<z<1.83 at a line flux
erg s cm, encompassing the peak of AGN activity at
) within the spectral coverage of the red grism. Outside this
redshift range, the measurement efficiency decreases significantly. Overall, a
spectroscopic redshift is correctly determined for ~90% of type 2 AGN down to
an emission line flux of erg s cm, and for type 1
AGN down to erg s cm. Recovered black hole mass
values show a small offset with respect to the input values ~10%, but the
agreement is good overall. With such a high spectroscopic coverage at z<2, we
will be able to measure AGN demography, scaling relations, and clustering from
the epoch of the peak of AGN activity down to the present-day Universe for
hundreds of thousand AGN with homogeneous spectroscopic information.Comment: 29 pages, 23 figures. Submitted to A&A, revised versio
Euclid preparation. Measuring detailed galaxy morphologies for Euclid with Machine Learning
The Euclid mission is expected to image millions of galaxies with high
resolution, providing an extensive dataset to study galaxy evolution. We
investigate the application of deep learning to predict the detailed
morphologies of galaxies in Euclid using Zoobot a convolutional neural network
pretrained with 450000 galaxies from the Galaxy Zoo project. We adapted Zoobot
for emulated Euclid images, generated based on Hubble Space Telescope COSMOS
images, and with labels provided by volunteers in the Galaxy Zoo: Hubble
project. We demonstrate that the trained Zoobot model successfully measures
detailed morphology for emulated Euclid images. It effectively predicts whether
a galaxy has features and identifies and characterises various features such as
spiral arms, clumps, bars, disks, and central bulges. When compared to
volunteer classifications Zoobot achieves mean vote fraction deviations of less
than 12% and an accuracy above 91% for the confident volunteer classifications
across most morphology types. However, the performance varies depending on the
specific morphological class. For the global classes such as disk or smooth
galaxies, the mean deviations are less than 10%, with only 1000 training
galaxies necessary to reach this performance. For more detailed structures and
complex tasks like detecting and counting spiral arms or clumps, the deviations
are slightly higher, around 12% with 60000 galaxies used for training. In order
to enhance the performance on complex morphologies, we anticipate that a larger
pool of labelled galaxies is needed, which could be obtained using
crowdsourcing. Finally, our findings imply that the model can be effectively
adapted to new morphological labels. We demonstrate this adaptability by
applying Zoobot to peculiar galaxies. In summary, our trained Zoobot CNN can
readily predict morphological catalogues for Euclid images.Comment: 27 pages, 26 figures, 5 tables, submitted to A&
Euclid Preparation. XXXVII. Galaxy colour selections with Euclid and ground photometry for cluster weak-lensing analyses
We derived galaxy colour selections from Euclid and ground-based photometry,
aiming to accurately define background galaxy samples in cluster weak-lensing
analyses. Given any set of photometric bands, we developed a method for the
calibration of optimal galaxy colour selections that maximises the selection
completeness, given a threshold on purity. We calibrated galaxy selections
using simulated ground-based and Euclid
photometry. Both selections produce a purity higher than 97%. The
selection completeness ranges from 30% to 84% in the lens redshift range
. With the full
selection, the completeness improves by up to percentage points, and the
range extends up to . The calibrated colour
selections are stable to changes in the sample limiting magnitudes and
redshift, and the selection based on bands provides excellent results on
real external datasets. The selection is also purer at high redshift and
more complete at low redshift compared to colour selections found in the
literature. We find excellent agreement in terms of purity and completeness
between the analysis of an independent, simulated Euclid galaxy catalogue and
our calibration sample, except for galaxies at high redshifts, for which we
obtain up to 50 percent points higher completeness. The combination of colour
and photo- selections applied to simulated Euclid data yields up to 95%
completeness, while the purity decreases down to 92% at high . We
show that the calibrated colour selections provide robust results even when
observations from a single band are missing from the ground-based data.
Finally, we show that colour selections do not disrupt the shear calibration
for stage III surveys.Comment: 20 pages, 13 figures. Published by A&
Euclid preparation: XXXVIII. Spectroscopy of active galactic nuclei with NISP
The statistical distribution and evolution of key properties of active galactic nuclei (AGN), such as their accretion rate, mass, and spin, remains a subject of open debate in astrophysics. The ESA Euclid space mission, launched on July 1 2023, promises a breakthrough in this field. We create detailed mock catalogues of AGN spectra from the rest-frame near-infrared down to the ultraviolet -including emission lines -to simulate what Euclid will observe for both obscured (type 2) and unobscured (type 1) AGN. We concentrate on the red grisms of the NISP instrument, which will be used for the wide-field survey, opening a new window for spectroscopic AGN studies in the near-infrared. We quantify the efficiency in the redshift determination as well as in retrieving the emission line flux of the Hα+[N II] complex, as Euclid is mainly focused on this emission line, given that it is expected to be the brightest one in the probed redshift range. Spectroscopic redshifts are measured for 83% of the simulated AGN in the interval where the Hα is visible (i.e. 0.89 < z < 1.83 at a line flux of > 2 Ă 10-16 erg s-1 cm-2, encompassing the peak of AGN activity at z â 1 - 1.5) within the spectral coverage of the red grism. Outside this redshift range, the measurement efficiency decreases significantly. Overall, a spectroscopic redshift iscorrectly determined for about 90% of type 2 AGN down to an emission line flux of roughly 3 Ă 10-16 erg s-1 cm-2, and for type 1 AGN down to 8.5 Ă 10-16 erg s-1 cm-2. Recovered values for black hole mass show a small offset with respect to the input values by about 10%, but the agreement is good overall. With such a high spectroscopic coverage at z < 2, we will be able to measure AGN demography, scaling relations, and clustering from the epoch of the peak of AGN activity down to the present-day Universe for hundreds of thousands of AGN with homogeneous spectroscopic information
- âŠ