129 research outputs found
Uv-to-fir analysis of spitzer/irac sources in the extended groth strip i: Multi-wavelength photometry and spectral energy distributions
We present an IRAC 3.6+4.5 microns selected catalog in the Extended Groth
Strip (EGS) containing photometry from the ultraviolet to the far-infrared and
stellar parameters derived from the analysis of the multi-wavelength data. In
this paper, we describe the method used to build coherent spectral energy
distributions (SEDs) for all the sources. In a companion paper, we analyze
those SEDs to obtain robust estimations of stellar parameters such as
photometric redshifts, stellar masses, and star formation rates. The catalog
comprises 76,936 sources with [3.6]<23.75 mag (85% completeness level of the
IRAC survey in the EGS) over 0.48 square degrees. For approximately 16% of this
sample, we are able to deconvolve the IRAC data to obtain robust fluxes for the
multiple counterparts found in ground-based optical images. Typically, the SEDs
of the IRAC sources in our catalog count with more than 15 photometric data
points, spanning from the UV to the FIR. Approximately 95% and 90% of all IRAC
sources are detected in the deepest optical and near-infrared bands. Only 10%
of the sources have optical spectroscopy and redshift estimations. Almost 20%
and 2% of the sources are detected by MIPS at 24 and 70 microns, respectively.
We also cross-correlate our catalog with public X-ray and radio catalogs.
Finally, we present the Rainbow Navigator public web-interface utility designed
to browse all the data products resulting from this work, including images,
spectra, photometry, and stellar parameters.Comment: 28 pages, 12 figures, Accepted for publication in ApJ. Access the
Rainbow Database at: http://rainbowx.fis.ucm.e
The stellar mass assembly of galaxies from z=0 to z=4. Analysis of a sample selected in the rest-frame near-infrared with Spitzer
Using a sample of ~28,000 sources selected at 3.6-4.5 microns with Spitzer
observations of the HDF-N, the CDF-S, and the Lockman Hole (surveyed area: ~664
arcmin^2), we study the evolution of the stellar mass content of the Universe
at 0<z<4. We calculate stellar masses and photometric redshifts, based on
~2,000 templates built with stellar and dust emission models fitting the
UV-to-MIR SEDs of galaxies with spectroscopic redshifts. We estimate stellar
mass functions for different redshift intervals. We find that 50% of the local
stellar mass density was assembled at 0<z<1 (average SFR:0.048 M_sun/yr/Mpc^3),
and at least another 40% at 1<z<4 (average SFR: 0.074 M_sun/yr/Mpc^3). Our
results confirm and quantify the ``downsizing'' scenario of galaxy formation.
The most massive galaxies (M>10^12.0 M_sun) assembled the bulk of their stellar
content rapidly (in 1-2 Gyr) beyond z~3 in very intense star formation events
(producing high specific SFRs). Galaxies with 10^11.5<M/M_sun<10^12.0 assembled
half of their stellar mass before z~1.5, and more than 90% of their mass was
already in place at z~0.6. Galaxies with M<10^11.5 M_sun evolved more slowly
(presenting smaller specific SFRs), assembling half of their stellar mass below
z~1. About 40% of the local stellar mass density of 10^9.0<M/M_sun<10^11.0
galaxies was assembled below z~0.4, most probably through accretion of small
satellites producing little star formation. The cosmic stellar mass density at
z>2.5 is dominated by optically faint (R>25) red galaxies (Distant Red Galaxies
or BzK sources) which account for ~30% of the global population of galaxies,
but contribute at least 60% to the cosmic stellar mass density. Bluer galaxies
(e.g., Lyman Break Galaxies) are more numerous but less massive, contributing
less than 50% to the global stellar mass density at high redshift.Comment: Published in ApJ. 38 pages, 10 figures, 5 tables, 2 appendices. Some
changes to match the final published versio
Epigenetics modifications and Subclinical Atherosclerosis in Obstructive Sleep Apnea: The EPIOSA study.
Background
Obstructive sleep apnea (OSA) is associated with increased risk for cardiovascular morbidity and mortality. Epidemiological and animal models studies generate hypotheses for innovative strategies in OSA management by interferig intermediates mechanisms associated with cardiovascular complications. We have thus initiated the Epigenetics modification in Obstructive Sleep Apnea (EPIOSA) study (ClinicalTrials.gov identifier: NCT02131610).
Methods/design
EPIOSA is a prospective cohort study aiming to recruit 350 participants of caucasian ethnicity and free of other chronic or inflammatory diseases: 300 patients with prevalent OSA and 50 non-OSA subjects. All of them will be follow-up for at least 5 years. Recruitment and study visits are performed in single University-based sleep clinic using standard operating procedures. At baseline and at each one year follow-up examination, patients are subjected to a core phenotyping protocol. This includes a standardized questionnaire and physical examination to determine incident comorbidities and health resources utilization, with a primary focus on cardiovascular events. Confirmatory outcomes information is requested from patient records and the regional Department of Health Services. Every year, OSA status will be assessed by full sleep study and blood samples will be obtained for immediate standard biochemistry, hematology, inflammatory cytokines and cytometry analysis. For biobanking, aliquots of serum, plasma, urine, mRNA and DNA are also obtained. Bilateral carotid echography will be performed to assess subclinical atherosclerosis and atherosclerosis progression. OSA patients are treated according with national guidelines.
Discussion
EPIOSA will enable the prospective evaluation of inflammatory and epigenetics mechanism involved in cardiovascular complication of treated and non-treated patients with OSA compared with non OSA subjects
UV-to-FIR analysis of Spitzer/IRAC sources in the Extended Groth Strip II: Photometric redshifts, Stellar masses and Star formation rates
Based on the ultraviolet to far-infrared photometry already compiled and
presented in a companion paper (Barro et al. 2011a, Paper I), we present a
detailed SED analysis of nearly 80,000 IRAC 3.6+4.5 micron selected galaxies in
the Extended Groth Strip. We estimate photometric redshifts, stellar masses,
and star formation rates separately for each galaxy in this large sample. The
catalog includes 76,936 sources with [3.6] < 23.75 (85% completeness level of
the IRAC survey) over 0.48 square degrees. The typical photometric redshift
accuracy is Delta z/(1+z)=0.034, with a catastrophic outlier fraction of just
2%. We quantify the systematics introduced by the use of different stellar
population synthesis libraries and IMFs in the calculation of stellar masses.
We find systematic offsets ranging from 0.1 to 0.4 dex, with a typical scatter
of 0.3 dex. We also provide UV- and IR-based SFRs for all sample galaxies,
based on several sets of dust emission templates and SFR indicators. We
evaluate the systematic differences and goodness of the different SFR
estimations using the deep FIDEL 70 micron data available in the EGS. Typical
random uncertainties of the IR-bases SFRs are a factor of two, with
non-negligible systematic effects at z1.5 observed when only MIPS 24
micron data is available. All data products (SEDs, postage stamps from imaging
data, and different estimations of the photometric redshifts, stellar masses,
and SFRs of each galaxy) described in this and the companion paper are publicly
available, and they can be accessed through our the web-interface utility
Rainbow-navigatorComment: 39 pages, 22 figures, Accepted for publication in ApJ. Access the
Rainbow Database at: http://rainbowx.fis.ucm.e
ECLIM-SEHOP, a new platform to set up and develop international academic clinical trials for childhood cancer and blood disorders in Spain
Introduction: Cancer and blood disorders in children are rare. The progressive improvement in survival over the last decades largely relies on the development of international academic clinical trials that gather the sufcient number of patients globally to elaborate solid conclusions and drive changes in clinical practice. The participation of Spain into large international academic trials has traditionally lagged behind of other European countries, mainly due to the burden of administrative tasks to open new studies, lack of fnancial support and limited research infrastructure in our hospitals. Methods: The objective of ECLIM-SEHOP platform (Ensayos ClĂnicos Internacionales MulticĂ©ntricos-SEHOP) is to overcome these difculties and position Spain among the European countries leading the advances in cancer and blood disorders, facilitate the access of our patients to novel diagnostic and therapeutic approaches and, most importantly, continue to improve survival and reducing long-term sequelae. ECLIM-SEHOP provides to the Spanish clinical investigators with the necessary infrastructural support to open and implement academic clinical trials and registries. Results: In less than 3 years from its inception, the platform has provided support to 20 clinical trials and 8 observational studies, including 8 trials and 4 observational studies where the platform performs all trial-related tasks (integral support: trial setup, monitoring, etc.) with more than 150 patients recruited since 2017 to these studies. In this manuscript, we provide baseline metrics for academic clinical trial performance that permit future comparisons. Conclusions: ECLIM-SEHOP facilitates Spanish children and adolescents diagnosed with cancer and blood disorders to access state-of-the-art diagnostic and therapeutic strategies
Efficacy and safety of preoperative preparation with Lugol''s iodine solution in euthyroid patients with Gravesâ disease (LIGRADIS Trial): Study protocol for a multicenter randomized trial
Background: Currently, both the American Thyroid Association and the European Thyroid Association recommend preoperative preparation with Lugol''s Solution (LS) for patients undergoing thyroidectomy for Gravesâ Disease (GD), but their recommendations are based on low-quality evidence. The LIGRADIS trial aims to provide evidence either to support or refute the systematic use of LS in euthyroid patients undergoing thyroidectomy for GD. Methods: A multicenter randomized controlled trial will be performed. Patients =18 years of age, diagnosed with GD, treated with antithyroid drugs, euthyroid and proposed for total thyroidectomy will be eligible for inclusion. Exclusion criteria will be prior thyroid or parathyroid surgery, hyperparathyroidism that requires associated parathyroidectomy, thyroid cancer that requires adding a lymph node dissection, iodine allergy, consumption of lithium or amiodarone, medically unfit patients (ASA-IV), breastfeeding women, preoperative vocal cord palsy and planned endoscopic, video-assisted or remote access surgery. Between January 2020 and January 2022, 270 patients will be randomized for either receiving or not preoperative preparation with LS. Researchers will be blinded to treatment assignment. The primary outcome will be the rate of postoperative complications: hypoparathyroidism, recurrent laryngeal nerve injury, hematoma, surgical site infection or death. Secondary outcomes will be intraoperative events (Thyroidectomy Difficulty Scale score, blood loss, recurrent laryngeal nerve neuromonitoring signal loss), operative time, postoperative length of stay, hospital readmissions, permanent complications and adverse events associated to LS. Conclusions: There is no conclusive evidence supporting the benefits of preoperative treatment with LS in this setting. This trial aims to provide new insights into future Clinical Practice Guidelines recommendations. Trial registration: ClinicalTrials.gov identifier: NCT03980132. © 202
Evolution of the observed Ly-alpha luminosity function from z = 6.5 to z = 7.7: evidence for the epoch of reionization ?
Aims. Ly-alpha emitters (LAEs) can be detected out to very high redshifts
during the epoch of reionization. The evolution of the LAE luminosity function
with redshift is a direct probe of the Ly-alpha transmission of the
intergalactic medium (IGM), and therefore of the IGM neutral-hydrogen fraction.
Measuring the Ly-alpha luminosity function (LF) of LAEs at redshift z = 7.7
therefore allows us to constrain the ionizing state of the Universe at this
redshift.
Methods. We observed three 7.5'x7.5' fields with the HAWK-I instrument at the
VLT with a narrow band filter centred at 1.06 m and targeting LAEs at
redshift z ~ 7.7. The fields were chosen for the availability of
multiwavelength data. One field is a galaxy cluster, the Bullet Cluster, which
allowed us to use gravitational amplification to probe luminosities that are
fainter than in the field. The two other fields are subareas of the GOODS
Chandra Deep Field South and CFHTLS-D4 deep field. We selected z=7.7 LAE
candidates from a variety of colour criteria, in particular from the absence of
detection in the optical bands.
Results. We do not find any LAE candidates at z = 7.7 in ~2.4 x 10^4 Mpc^3
down to a narrow band AB magnitude of ~ 26, which allows us to infer robust
constraints on the Ly-alpha LAE luminosity function at this redshift.
Conclusions. The predicted mean number of objects at z = 6.5, derived from
somewhat different LFs of Hu et al. (2010), Ouchi et al. (2010), and Kashikawa
et al. (2011) are 2.5, 13.7, and 11.6, respectively. Depending on which of
these LFs we refer to, we exclude a scenario with no evolution from z = 6.5 to
z = 7.7 at 85% confidence without requiring a strong change in the IGM Ly-alpha
transmission, or at 99% confidence with a significant quenching of the IGM
Ly-alpha transmission, possibly from a strong increase in the high
neutral-hydrogen fraction between these two redshifts.Comment: 14 pages, 6 figures, accepted for publication in A&A. Added
references, minor changes applied in text and figures after the first referee
repor
Activation of NF-kB Pathway by Virus Infection Requires Rb Expression
The retinoblastoma protein Rb is a tumor suppressor involved in cell cycle control, differentiation, and inhibition of oncogenic transformation. Besides these roles, additional functions in the control of immune response have been suggested. In the present study we investigated the consequences of loss of Rb in viral infection. Here we show that virus replication is increased by the absence of Rb, and that Rb is required for the activation of the NF-kB pathway in response to virus infection. These results reveal a novel role for tumor suppressor Rb in viral infection surveillance and further extend the concept of a link between tumor suppressors and antiviral activity
MEGARA developments at LICA-UCM
LICA-UCM is the brand new laboratory for scientific advanced instrumentation (Laboratorio de Investigacion Cientifica Avanzada) at Universidad Complutense de Madrid where MEGARA integration will take place
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