37 research outputs found
Effects of superstructure environment on galaxy groups
We analyse properties of galaxy groups and their dependence on the large-scale environment as defined by superstructures. We find that group–galaxy cross–correlations depend only on group properties regardless the groups reside in superstructures. This indicates that the total galaxy density profile around groups is independent of the global environment. At a given global luminosity, a proxy to group total mass, groups have a larger stellar mass content by a factor 1.3, a relative excess independent of the group luminosity. Groups in superstructures have 40 per cent higher velocity dispersions and systematically larger minimal enclosing radii. We also find that the stellar population of galaxies in groups in superstructures is systematically older as infered from the galaxy spectra Dn 4000 parameter. Although the galaxy number density profile of groups is independent of environment, the star–formation rate and stellar mass profile of the groups residing in superstructures differs from groups elsewhere. For groups residing in superstructures, the combination of a larger stellar mass content and star–formation rate produces a larger time–scale for star formation regardless the distance to the group center. Our results provide evidence that groups in superstructures formed earlier than elsewhere, as expected in the assembly bias scenario.publishedVersio
Planck Intermediate Results. XXXVI. Optical identification and redshifts of Planck SZ sources with telescopes at the Canary Islands Observatories
We present the results of approximately three years of observations of Planck
Sunyaev-Zeldovich (SZ) sources with telescopes at the Canary Islands
observatories as part of the general optical follow-up programme undertaken by
the Planck collaboration. In total, 78 SZ sources are discussed. Deep-imaging
observations were obtained for most of these sources; spectroscopic
observations in either in long-slit or multi-object modes were obtained for
many. We effectively used 37.5 clear nights. We found optical counterparts for
73 of the 78 candidates. This sample includes 53 spectroscopic redshift
determinations, 20 of them obtained with a multi-object spectroscopic mode. The
sample contains new redshifts for 27 Planck clusters that were not included in
the first Planck SZ source catalogue (PSZ1).Comment: 15 pages, 14 figures, accepted for publication in A&
Minimum distance index for non-square complex valued mixing matrices
We consider complex valued linear blind source separation, where the objective is to estimate a subset of the latent sources. In order to measure the success of the signal separation, we propose an extension of the minimum distance index and establish its properties. Interpretations for the index are derived through connections to signal-to-noise ratios and correlations. The interpretations are novel also for the square real valued (original) case.N. Lietzen gratefully acknowledges financial support from the Emil Aaltonen Foundation (grant 180144). The authors would also like to thank the anonymous referee
Minimum distance index for non-square complex valued mixing matrices
We consider complex valued linear blind source separation, where the objective is to estimate a subset of the latent sources. In order to measure the success of the signal separation, we propose an extension of the minimum distance index and establish its properties. Interpretations for the index are derived through connections to signal-to-noise ratios and correlations. The interpretations are novel also for the square real valued (original) case.N. Lietzen gratefully acknowledges financial support from the Emil Aaltonen Foundation (grant 180144). The authors would also like to thank the anonymous referee
Predictors of re-operation due to post-surgical bleeding in breast cancer patients:a Danish population-based cohort study
Work-related stress and asthma: results from a workforce survey in New Zealand.
OBJECTIVE: We assessed the association between work-related stress and asthma in a cross-sectional workforce survey in New Zealand. METHODS: Men and women randomly selected from the Electoral Roll were invited to take part in a telephonic interview, which collected information on current workplace exposures and respiratory symptoms. Participants rated how stressful they found their current job on a five-point scale. We conducted unconditional logistic regression to calculate prevalence odds ratios (OR) and 95% confidence intervals (CI) for job stress and both current and adult-onset asthma, adjusting for age, sex, smoking, and deprivation. Analyses were also stratified by sex, smoking status, body mass index, and age group. RESULTS: Results were based on 2903 interviews. Participants with very or extremely stressful jobs were twice as likely to have current asthma (OR = 1.98; 95% CI = 1.52-2.58) and 50% more likely to have adult-onset asthma (OR = 1.50; 95% CI = 1.05-2.15) compared to those with not at all or mildly stressful jobs. This association was evident for both sexes and was not explained by either occupation, age, body mass index, or smoking, although the results did differ by smoking status. CONCLUSION: Our study adds to the sparse evidence on the relationship between work-related stress and asthma in adult working populations
Characterization of a subsample of the
Aims. The Planck catalogues of Sunyaev –Zeldovich (SZ) sources, PSZ1 and PSZ2, are the largest catalogues of galaxy clusters selected through their SZ signature in the full sky. In 2013, we started a long-term observational programme at Canary Island observatories with the aim of validating ∼500 unconfirmed SZ sources. In this work we present results of the initial pre-screening of possible cluster counterparts using photometric and spectroscopic data of the Sloan Digital Sky Survey DR12. Our main aim is to identify previously unconfirmed PSZ2 cluster candidates and to contribute in the determination of the actual purity and completeness of Planck SZ source sample.
Methods. Using the latest version of the PSZ2 catalogue, we selected all sources overlapping with the SDSS DR12 footprint and without redshift information. We validated these cluster fields following optical criteria (mainly distance with respect to the Planck pointing, magnitude of the brightest cluster galaxy, and cluster richness), and combined these criteria with the profiles of the Planck Compton y-maps. This combined procedure allows for a more robust identification of optical counterparts compared to simply cross-matching with existing SDSS cluster catalogues that have been constructed from earlier SDSS data releases.
Results. The sample contains new redshifts for 37 Planck galaxy clusters that were not included in the original release of PSZ2 Planck catalogue. We detect three cases as possible multiple counterparts. We show that a combination of all available information (optical images and profile of SZ signal) can provide correct associations between the observed Planck SZ source and the optically identified cluster. We also show that Planck SZ detection is very sensitive even to high-z (z > 0.5) clusters. In addition, we also present updated spectroscopic information for 34 Planck PSZ1 sources (33 previously photometrically confirmed and 1 new identification)
Post-transcriptional regulation of human breast cancer cell proteome by unliganded Estrogen Receptor beta via microRNAs.
Estrogen Receptor β (ERβ) is a member of the nuclear receptor family of homeostatic regulators that is frequently lost in breast cancer (BC), where its presence correlates with a better prognosis and a less aggressive clinical outcome of the disease. Contrary to ERα, its closest homolog, ERβ shows also significant estrogen-independent activities, including the ability to inhibit cell cycle progression and to regulate gene transcription in the absence of the ligand. Investigating the nature and extent of this constitutive activity of ERβ in BC MCF-7 and ZR-75.1 cells by miRNA-Seq, we identified 30 miRNAs differentially expressed in ERβ+ vs ERβ- cells in the absence of ligand, including upregulated oncosuppressor miRs, such miR-30a. In addition, a significant fraction of >1,600 unique proteins identified in MCF-7 cells by iTRAQ (isobaric Tag for Relative and Absolute Quantitation) quantitative proteomics was either increased or decreased by ERβ, revealing regulation of multiple cell pathways by ligand-free receptor. Transcriptome analysis show that for a large number of proteins regulated by ERβ the corresponding mRNAs are unaffected, including a large number of putative targets of ERβ-regulated miRNAs, indicating a central role of miRNAs in mediating BC cell proteome regulation by ERβ. Expression of a mimic of miR-30a-5p, a direct target and downstream effector of ERβ in BC, led to the identification of several target transcripts of this miRNA, including 11 encoding proteins whose intracellular concentration is significantly affected by unliganded receptor. These results demonstrate a significant effect of ligand-free ERβ on BC cell functions via modulation of the cell proteome and suggest that miRNA regulation may represent a key event in the control of the biological and clinical phenotype of hormone-responsive BC by this nuclear receptor
Optical validation and characterization of Planck PSZ1 sources at the Canary Islands observatories
International audienc
Optical validation and characterisation of Planck PSZ1 sources at the Canary Islands observatories: II. Second year of ITP13 observations
We report new galaxy clusters previously unknown included in the first Planck Sunyaev–Zeldovich (SZ) sources catalogue, the PSZ1. The results presented here were achieved during the second year of a two-year observational programme, the ITP13, developed at the Roque de los Muchachos Observatory (La Palma, Spain). Using the 2.5 m Isaac Newton telescope, the 3.5 m Telescopio Nazionale Galileo, the 4.2 m William Herschel telescope and the 10.4 m Gran Telescopio Canarias we characterised 75 SZ sources with low SZ significance, SZ S < 5.32. We performed deep optical imaging and spectroscopy in order to associate actual galaxy clusters with the SZ Planck source. We adopted robust criteria, based on the 2D spatial distribution, richness, and velocity dispersions to confirm actual optical counterparts up to z < 0.85. The selected systems are confirmed only if they are well aligned with respect to the PSZ1 coordinate and show high richness and high velocity dispersion. In addition, we also inspected the Compton y-maps and SZ significance in order to identify unrealistic detections. Following this procedure, we identify 26 cluster counterparts associated with the SZ emission, which means that only about 35% of the clusters considered in this low S/N PSZ1 subsample are validated. Forty-nine SZ sources (∼65% of this PSZ1 subset) remain unconfirmed. At the end of the ITP13 observational programme, we have studied 256 SZ sources with Dec ≥ −15° (212 of them completely unknown), finding optical counterparts for 152 SZ sources. The ITP13 validation programme has allowed us to update the PSZ1 purity, which is now more refined, increasing from 72% to 83% in the low SZ S/N regime. Our results are consistent with the predicted purity curve for the full PSZ1 catalogue and with the expected fraction of false detections caused by the non-Gaussian noise of foreground signals. We find a strong correlation between the number of unconfirmed sources and the thermal emission of diffuse galactic dust at 857 GHz, thus increasing the fraction of false Planck SZ detections at low galactic latitudes