8,925 research outputs found
Stellar populations of galaxies in the ALHAMBRA survey up to . I. MUFFIT: A Multi-Filter Fitting code for stellar population diagnostics
We present MUFFIT, a new generic code optimized to retrieve the main stellar
population parameters of galaxies in photometric multi-filter surveys, and we
check its reliability and feasibility with real galaxy data from the ALHAMBRA
survey. Making use of an error-weighted -test, we compare the
multi-filter fluxes of galaxies with the synthetic photometry of mixtures of
two single stellar populations at different redshifts and extinctions, to
provide through a Monte Carlo method the most likely range of stellar
population parameters (mainly ages and metallicities), extinctions, redshifts,
and stellar masses. To improve the diagnostic reliability, MUFFIT identifies
and removes from the analysis those bands that are significantly affected by
emission lines. We highlight that the retrieved age-metallicity locus for a
sample of early-type galaxies in ALHAMBRA at different stellar
mass bins are in very good agreement with the ones from SDSS spectroscopic
diagnostics. Moreover, a one-to-one comparison between the redshifts, ages,
metallicities, and stellar masses derived spectroscopically for SDSS and by
MUFFIT for ALHAMBRA reveals good qualitative agreements in all the parameters.
In addition, and using as input the results from photometric-redshift codes,
MUFFIT improves the photometric-redshift accuracy by -, and it
also detects nebular emissions in galaxies, providing physical information
about their strengths. Our results show the potential of multi-filter galaxy
data to conduct reliable stellar population studies with the appropiate
analysis techniques, as MUFFIT.Comment: 31 pages, 18 figures, accepted for publication in A&
The ALHAMBRA Survey: Bayesian Photometric Redshifts with 23 bands for 3 squared degrees
The ALHAMBRA (Advance Large Homogeneous Area Medium Band Redshift
Astronomical) survey has observed 8 different regions of the sky, including
sections of the COSMOS, DEEP2, ELAIS, GOODS-N, SDSS and Groth fields using a
new photometric system with 20 contiguous ~ filters covering the
optical range, combining them with deep imaging. The observations,
carried out with the Calar Alto 3.5m telescope using the wide field (0.25 sq.
deg FOV) optical camera LAICA and the NIR instrument Omega-2000, correspond to
~700hrs on-target science images. The photometric system was designed to
maximize the effective depth of the survey in terms of accurate spectral-type
and photo-zs estimation along with the capability of identification of
relatively faint emission lines. Here we present multicolor photometry and
photo-zs for ~438k galaxies, detected in synthetic F814W images, complete down
to I~24.5 AB, taking into account realistic noise estimates, and correcting by
PSF and aperture effects with the ColorPro software. The photometric ZP have
been calibrated using stellar transformation equations and refined internally,
using a new technique based on the highly robust photometric redshifts measured
for emission line galaxies. We calculate photometric redshifts with the BPZ2
code, which includes new empirically calibrated templates and priors. Our
photo-zs have a precision of for I<22.5 and 1.4% for
22.5<I<24.5. Precisions of less than 0.5% are reached for the brighter
spectroscopic sample, showing the potential of medium-band photometric surveys.
The global shows a mean redshift =0.56 for I=0.86 for
I<24.5 AB. The data presented here covers an effective area of 2.79 sq. deg,
split into 14 strips of 58.5'x15.5' and represents ~32 hrs of on-target.Comment: The catalog data and a full resolution version of this paper is
available at https://cloud.iaa.csic.es/alhambra
Chronic Obstructive Pulmonary Disease (COPD) as a disease of early aging: Evidence from the EpiChron Cohort
Background Aging is an important risk factor for most chronic diseases. Patients with COPD develop more comorbidities than non-COPD subjects. We hypothesized that the development of comorbidities characteristically affecting the elderly occur at an earlier age in subjects with the diagnosis of COPD. Methods and findings We included all subjects carrying the diagnosis of COPD (n = 27, 617), and a similar number of age and sex matched individuals without the diagnosis, extracted from the 727, 241 records of individuals 40 years and older included in the EpiChron Cohort (Aragon, Spain). We compared the cumulative number of comorbidities, their prevalence and the mortality risk between both groups. Using network analysis, we explored the connectivity between comorbidities and the most influential comorbidities in both groups. We divided the groups into 5 incremental age categories and compared their comorbidity networks. We then selected those comorbidities known to affect primarily the elderly and compared their prevalence across the 5 age groups. In addition, we replicated the analysis in the smokers'' subgroup to correct for the confounding effect of cigarette smoking. Subjects with COPD had more comorbidities and died at a younger age compared to controls. Comparison of both cohorts across 5 incremental age groups showed that the number of comorbidities, the prevalence of diseases characteristic of aging and network''s density for the COPD group aged 56-65 were similar to those of non-COPD 15 to 20 years older. The findings persisted after adjusting for smoking. Conclusion Multimorbidity increases with age but in patients carrying the diagnosis of COPD, these comorbidities are seen at an earlier age
CD69 is a TGF-β/1α,25-dihydroxyvitamin D3 target gene in monocytes
CD69 is a transmembrane lectin that can be expressed on most hematopoietic cells. In monocytes, it has been functionally linked to the 5-lipoxygenase pathway in which the leukotrienes, a class of highly potent inflammatory mediators, are produced. However, regarding CD69 gene expression and its regulatory mechanisms in monocytes, only scarce data are available. Here, we report that CD69 mRNA expression, analogous to that of 5-lipoxygenase, is induced by the physiologic stimuli transforming growth factor-β (TGF-β) and 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3) in monocytic cells. Comparison with T- and B-cell lines showed that the effect was specific for monocytes. CD69 expression levels were increased in a concentration-dependent manner, and kinetic analysis revealed a rapid onset of mRNA expression, indicating that CD69 is a primary TGF-β/1α,25(OH)2D3 target gene. PCR analysis of different regions of the CD69 mRNA revealed that de novo transcription was initiated and proximal and distal parts were induced concomitantly. In common with 5-lipoxygenase, no activation of 0.7 kb or ~2.3 kb promoter fragments by TGF-β and 1α,25(OH)2D3 could be observed in transient reporter assays for CD69. Analysis of mRNA stability using a transcription inhibitor and a 3′UTR reporter construct showed that TGF-β and 1α,25(OH)2D3 do not influence CD69 mRNA stability. Functional knockdown of Smad3 clearly demonstrated that upregulation of CD69 mRNA, in contrast to 5-LO, depends on Smad3. Comparative studies with different inhibitors for mitogen activated protein kinases (MAPKs) revealed that MAPK signalling is involved in CD69 gene regulation, whereas 5-lipoxygenase gene expression was only partly affected. Mechanistically, we found evidence that CD69 gene upregulation depends on TAK1-mediated p38 activation. In summary, our data indicate that CD69 gene expression, conforming with 5-lipoxygenase, is regulated monocyte-specifically by the physiologic stimuli TGF-β and 1α,25(OH)2D3 on mRNA level, although different mechanisms account for the upregulation of each gene
CDMSlite: A Search for Low-Mass WIMPs using Voltage-Assisted Calorimetric Ionization Detection in the SuperCDMS Experiment
SuperCDMS is an experiment designed to directly detect Weakly Interacting
Massive Particles (WIMPs), a favored candidate for dark matter ubiquitous in
the Universe. In this paper, we present WIMP-search results using a
calorimetric technique we call CDMSlite, which relies on voltage- assisted
Luke-Neganov amplification of the ionization energy deposited by particle
interactions. The data were collected with a single 0.6 kg germanium detector
running for 10 live days at the Soudan Underground Laboratory. A low energy
threshold of 170 eVee (electron equivalent) was obtained, which allows us to
constrain new WIMP-nucleon spin-independent parameter space for WIMP masses
below 6 GeV/c2.Comment: 7 pages, 4 figure
VAMOS: a Pathfinder for the HAWC Gamma-Ray Observatory
VAMOS was a prototype detector built in 2011 at an altitude of 4100m a.s.l.
in the state of Puebla, Mexico. The aim of VAMOS was to finalize the design,
construction techniques and data acquisition system of the HAWC observatory.
HAWC is an air-shower array currently under construction at the same site of
VAMOS with the purpose to study the TeV sky. The VAMOS setup included six water
Cherenkov detectors and two different data acquisition systems. It was in
operation between October 2011 and May 2012 with an average live time of 30%.
Besides the scientific verification purposes, the eight months of data were
used to obtain the results presented in this paper: the detector response to
the Forbush decrease of March 2012, and the analysis of possible emission, at
energies above 30 GeV, for long gamma-ray bursts GRB111016B and GRB120328B.Comment: Accepted for pubblication in Astroparticle Physics Journal (20 pages,
10 figures). Corresponding authors: A.Marinelli and D.Zaboro
Indication for the disappearance of reactor electron antineutrinos in the Double Chooz experiment
The Double Chooz Experiment presents an indication of reactor electron
antineutrino disappearance consistent with neutrino oscillations. A ratio of
0.944 0.016 (stat) 0.040 (syst) observed to predicted events was
obtained in 101 days of running at the Chooz Nuclear Power Plant in France,
with two 4.25 GW reactors. The results were obtained from a single 10
m fiducial volume detector located 1050 m from the two reactor cores. The
reactor antineutrino flux prediction used the Bugey4 measurement as an anchor
point. The deficit can be interpreted as an indication of a non-zero value of
the still unmeasured neutrino mixing parameter \sang. Analyzing both the rate
of the prompt positrons and their energy spectrum we find \sang = 0.086
0.041 (stat) 0.030 (syst), or, at 90% CL, 0.015 \sang 0.16.Comment: 7 pages, 4 figures, (new version after PRL referee's comments
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