39 research outputs found
Higher prevalence of X-ray selected AGN in intermediate age galaxies up to z~1
We analyse the stellar populations in the host galaxies of 53 X-ray selected
optically dull active galactic nuclei (AGN) at 0.34<z<1.07 with ultra-deep
(m=26.5) optical medium-band (R~50) photometry from the Survey for High-z
Absorption Red and Dead Sources (SHARDS). The spectral resolution of SHARDS
allows us to consistently measure the strength of the 4000 AA break, Dn(4000),
a reliable age indicator for stellar populations. We confirm that most X-ray
selected moderate-luminosity AGN (L_X<10^44 erg/s) are hosted by massive
galaxies (typically M*>10^10.5 M_sun) and that the observed fraction of
galaxies hosting an AGN increases with the stellar mass. A careful selection of
random control samples of inactive galaxies allows us to remove the stellar
mass and redshift dependencies of the AGN fraction to explore trends with
several stellar age indicators. We find no significant differences in the
distribution of the rest-frame U-V colour for AGN hosts and inactive galaxies,
in agreement with previous results. However, we find significantly shallower
4000 AA breaks in AGN hosts, indicative of younger stellar populations. With
the help of a model-independent determination of the extinction, we obtain
extinction-corrected U-V colours and light-weighted average stellar ages. We
find that AGN hosts have younger stellar populations and higher extinction
compared to inactive galaxies with the same stellar mass and at the same
redshift. We find a highly significant excess of AGN hosts with Dn(4000)~1.4
and light weighted average stellar ages of 300-500 Myr, as well as a deficit of
AGN in intrinsic red galaxies. We interpret failure in recognising these trends
in previous studies as a consequence of the balancing effect in observed
colours of the age-extinction degeneracy.Comment: Accepted for publication in MNRAS, 12 pages, 8 figures, 1 tabl
Spitzer view on the downsizing scenario of galaxy formation and the role of AGN
We present the latest results of the Spitzer Cosmological Surveys concerning the characterization of the evolution of galaxies in the last 12 Gyr (from z=4). We have analyzed the stellar mass function up to z=4 using a sample of more the 28,000 galaxies selected in the rest-frame near-infrared with Spitzer/IRAC. Our results confirm and quantify the âdownsizingâ scenario of galaxy formation. Based on the study of the specific SFRs of X-ray emitters, we discuss the role of AGN in the evolution of galaxies, arguing against the link between nuclear activity and the quenching of the star formation in massive galaxies at z<1.4
SHARDS: A global view of the star formation activity at z~0.84 and z~1.23
In this paper, we present a comprehensive analysis of star-forming galaxies
(SFGs) at intermediate redshifts (z~1). We combine the ultra-deep optical
spectro-photometric data from the Survey for High-z Absorption Red and Dead
Sources (SHARDS) with deep UV-to-FIR observations in the GOODS-N field.
Exploiting two of the 25 SHARDS medium-band filters, F687W17 and F823W17, we
select [OII] emission line galaxies at z~0.84 and z~1.23 and characterize their
physical properties. Their rest-frame equivalent widths
(EW([OII])), line fluxes, luminosities, star formation rates
(SFRs) and dust attenuation properties are investigated. The evolution of the
EW([OII]) closely follows the SFR density evolution of the
universe, with a trend of EW([OII])(1+z) up to
redshift z~1, followed by a possible flattening. The SF properties of the
galaxies selected on the basis of their [OII] emission are compared with
complementary samples of SFGs selected by their MIR and FIR emission, and also
with a general mass-selected sample of galaxies at the same redshifts. We
demonstrate observationally that the UVJ diagram (or, similarly, a cut in the
specific SFR) is only partially able to distinguish the quiescent galaxies from
the SFGs. The SFR-M relation is investigated for the different samples,
yelding a logarithmic slope ~1, in good agreement with previous results. The
dust attenuations derived from different SFR indicators (UV(1600), UV(2800),
[OII], IR) are compared and show clear trends with respect to both the stellar
mass and total SFR, with more massive and highly star-forming galaxies being
affected by stronger dust attenuation.Comment: Replaced to match the accepted version (24 pages, 1 table, 17
figures). Published in ApJ, 812, 155 (2015):
http://stacks.iop.org/0004-637X/812/15
CSVS, a crowdsourcing database of the Spanish population genetic variability
The knowledge of the genetic variability of the local
population is of utmost importance in personalized
medicine and has been revealed as a critical
factor for the discovery of new disease variants.
Here, we present the Collaborative Spanish
Variability Server (CSVS), which currently contains
more than 2000 genomes and exomes of unrelated Spanish individuals. This database has been generated
in a collaborative crowdsourcing effort collecting
sequencing data produced by local genomic
projects and for other purposes. Sequences have
been grouped by ICD10 upper categories. A web interface
allows querying the database removing one
or more ICD10 categories. In this way, aggregated
counts of allele frequencies of the pseudo-control
Spanish population can be obtained for diseases belonging
to the category removed. Interestingly, in addition
to pseudo-control studies, some population
studies can be made, as, for example, prevalence of
pharmacogenomic variants, etc. In addition, this genomic
data has been used to define the first Spanish
Genome Reference Panel (SGRP1.0) for imputation.
This is the first local repository of variability entirely
produced by a crowdsourcing effort and constitutes
an example for future initiatives to characterize local
variabilityworldwide. CSVS is also part of the GA4GH
Beacon network.Spanish Ministry of Economy and Competitiveness
SAF2017-88908-R
PT17/0009/0006
PI19/00321
CIBERER ACCI-06/07/0036
PI14-948
PI171659Regional Government of Madrid, RAREGenomicsCM
B2017/BMD3721
B2017/BMD-3721European Union (EU)European Union (EU)
676559University Chair UAM-IIS-FJD of Genomic MedicineRamon Areces Foundatio
SHARDS: stellar populations and star formation histories of a mass-selected sample of 0.65 < z < 1.1 galaxies
We report on results from the analysis of a stellar mass-selected (logâ(M*/Mâ) â„ 9.0) sample of 1644 galaxies at 0.65 11, in agreement with downsizing scenarios
Dietary diversity and nutritional adequacy among an older Spanish population with metabolic syndrome in the PREDIMED-Plus study: a cross-sectional analysis
Dietary guidelines emphasize the importance of a varied diet to provide an adequate nutrient intake. However, an older age is often associated with consumption of monotonous diets that can be nutritionally inadequate, increasing the risk for the development or progression of diet-related chronic diseases, such as metabolic syndrome (MetS). To assess the association between dietary diversity (DD) and nutrient intake adequacy and to identify demographic variables associated with DD, we cross-sectionally analyzed baseline data from the PREDIMED-Plus trial: 6587 Spanish adults aged 55-75 years, with overweight/obesity who also had MetS. An energy-adjusted dietary diversity score (DDS) was calculated using a 143-item validated semi-quantitative food frequency questionnaire (FFQ). Nutrient inadequacy was defined as an intake below 2/3 of the dietary reference intake (DRI) forat least four of 17 nutrients proposed by the Institute of Medicine (IOM). Logistic regression models were used to evaluate the association between DDS and the risk of nutritionally inadequate intakes. In the higher DDS quartile there were more women and less current smokers. Compared with subjects in the highest DDS quartile, those in the lowest DDS quartile had a higher risk of inadequate nutrient intake: odds ratio (OR) = 28.56 (95% confidence interval (CI) 20.80-39.21). When we estimated food varietyfor each of the food groups, participants in the lowest quartile had a higher risk of inadequate nutrient intake for the groups of vegetables, OR = 14.03 (95% CI 10.55-18.65), fruits OR = 11.62 (95% CI 6.81-19.81), dairy products OR = 6.54 (95% CI 4.64-9.22) and protein foods OR = 6.60 (95% CI 1.96-22.24). As DDS decreased, the risk of inadequate nutrients intake rose. Given the impact of nutrient intake adequacy on the prevention of non-communicable diseases, health policies should focus on the promotion of a healthy varied diet, specifically promoting the intake of vegetables and fruit among population groups with lower DDS such as men, smokers or widow(er)s
A crowdsourcing database for the copy-number variation of the Spanish population
Background: Despite being a very common type of genetic variation, the distribution of copy-number variations (CNVs) in the population is still poorly understood. The knowledge of the genetic variability, especially at the level of the local population, is a critical factor for distinguishing pathogenic from non-pathogenic variation in the discovery of new disease variants. Results: Here, we present the SPAnish Copy Number Alterations Collaborative Server (SPACNACS), which currently contains copy number variation profiles obtained from more than 400 genomes and exomes of unrelated Spanish individuals. By means of a collaborative crowdsourcing effort whole genome and whole exome sequencing data, produced by local genomic projects and for other purposes, is continuously collected. Once checked both, the Spanish ancestry and the lack of kinship with other individuals in the SPACNACS, the CNVs are inferred for these sequences and they are used to populate the database. A web interface allows querying the database with different filters that include ICD10 upper categories. This allows discarding samples from the disease under study and obtaining pseudo-control CNV profiles from the local population. We also show here additional studies on the local impact of CNVs in some phenotypes and on pharmacogenomic variants. SPACNACS can be accessed at: http://csvs.clinbioinfosspa.es/spacnacs/. Conclusion: SPACNACS facilitates disease gene discovery by providing detailed information of the local variability of the population and exemplifies how to reuse genomic data produced for other purposes to build a local reference database
Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2
The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality
A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)
Meeting abstrac