A new measurement of the evolving near-infrared galaxy luminosity function out to z~4: a continuing challenge to theoretical models of galaxy formation

We present the most accurate measurement to date of cosmological evolution of the near-infrared galaxy luminosity function, from the local Universe out to z~4. The analysis is based on a large and highly complete sample of galaxies selected from the first data release of the UKIDSS Ultra Deep Survey. Exploiting a master catalogue of K- and z-band selected galaxies over an area of 0.7 square degrees, we analyse a sample of ~50,000 galaxies, all with reliable photometry in 16-bands from the far-ultraviolet to the mid-infrared. The unique combination of large area and depth provided by the Ultra Deep Survey allows us to trace the evolution of the K-band luminosity function with unprecedented accuracy. In particular, via a maximum likelihood analysis we obtain a simple parameterization for the luminosity function and its cosmological evolution, including both luminosity and density evolution, which provides an excellent description of the data from z =0 up to z~4. We find differential evolution for galaxies dependent on galaxy luminosity, revealing once again the ``down-sizing behaviour'' of galaxy formation. Finally, we compare our results with the predictions of the latest theoretical models of galaxy formation, based both on semi-analytical prescriptions, and on full hydrodynamical simulations.Comment: 11 pages, 6 figures, submitted to MNRA

Cosmic evolution of the CIV in high-resolution hydrodynamic simulations

We investigate the properties of triply ionized Carbon (CIV) in the Intergalactic Medium using a set of high-resolution and large box-size cosmological hydrodynamic simulations of a $\Lambda$CDM model. We rely on a modification of the GADGET-2 code that self-consistently follows the metal enrichment mechanism by means of a detailed chemical evolution model. We focus on several numerical implementations of galactic feedback: galactic winds in the energy driven and momentum driven prescriptions and Active Galactic Nuclei (AGN) powered by gas accretion onto massive black holes. We extract mock IGM transmission spectra in neutral hydrogen (HI) and CIV and perform Voigt profile fitting. The results are then compared with high-resolution quasar (QSO) spectra obtained with the UVES spectrograph at the VLT and the HIRES spectrograph at Keck. We find that feedback has little impact on statistics related to the neutral hydrogen, while CIV is more affected by galactic winds and/or AGN feedback. When the same analysis is performed over observed and simulated CIV lines, we find reasonables good agreement between data and simulations over the column density range $N_{\rm CIV}=10^{12.5-15}$ cm$^{-2}$. Also the CIV line-widths distribution appears to be in agreement with the observed values, while the HI Doppler parameters, $b_{\rm HI}$, are in general too large showing that the diffuse cosmic web is heated more than what is inferred by observations. The simulation without feedback fails in reproducing the CIV systems at high column densities at all redshift, while the AGN feedback case agrees with observations only at $z<3$, when this form of feedback is particularly effective. We also present scatter plots in the $b-N$ and in the $N_{\rm CIV}-N_{\rm HI}$ planes, showing that there is rough agreement between observations and simulations only when feedback is taken into account.Comment: 22 pages, 20 figures, minor revisions, accepted for publication in MNRA

Statin treatment and mortality in community-dwelling frail older patients with diabetes mellitus

Background: Older adults are often excluded from clinical trials. Decision making for administration of statins to older patients with diabetes mellitus (DM) is under debate, particularly in frail older patients with comorbidity and high mortality risk. We tested the hypothesis that statin treatment in older patients with DM was differentially effective across strata of mortality risk assessed by the Multidimensional Prognostic Index (MPI), based on information collected with the Standardized Multidimensional Assessment Schedule for Adults and Aged Persons (SVaMA). Methods: In this retrospective observational study, we estimated the mortality risk in 1712 community-dwelling subjects with DM ≥ 65 years who underwent a SVaMA evaluation to establish accessibility to homecare services/nursing home admission from 2005 to 2013 in the Padova Health District, Italy. Mild (MPI-SVaMA-1), moderate (MPI-SVaMA-2), and high (MPI-SVaMA-3) risk of mortality at baseline and propensity score-adjusted hazard ratios (HR) of three-year mortality were calculated according to statin treatment. Results: Higher MPI-SVaMA scores were associated with lower rates of statin treatment (MPI-SVaMA-1 = 39% vs MPI-SVaMA-2 = 36% vs MPI-SVaMA-3 = 24.9%. p<0.001) and higher three-year mortality (MPI-SVaMA-1 = 12.9% vs MPI-SVaMA-2 = 24% vs MPI-SVaMA-3 = 34.4%, p<0.001). After adjustment for propensity score quintiles, statin treatment was significantly associated with lower three-year mortality irrespective of MPI-SVaMA group (interaction test p = 0.303). HRs [95% confidence interval (CI)] were 0.19 (0.14-0.27), 0.28 (0.21-0.36), and 0.26 (0.20-0.34) in the MPI-SVaMA-1, MPI-SVaMA-2, and MPI-SVaMA-3 groups, respectively. Subgroup analyses showed that statin treatment was also beneficial irrespective of age. HRs (95% CI) were 0.21 (0.15-0.31), 0.26 (0.20-0.33), and 0.26 (0.20-0.35) among patients aged 65-74, 75-84, and ≥ 85 years, respectively (interaction test p=0.812). Conclusions: Statin treatment was significantly associat

Tracing the cosmic growth of supermassive black holes to z~3 with Herschel

We study a sample of Herschel selected galaxies within the Great Observatories Origins Deep Survey-South and the Cosmic Evolution Survey fields in the framework of the Photodetector Array Camera and Spectrometer (PACS) Evolutionary Probe project. Starting from the rich multiwavelength photometric data sets available in both fields, we perform a broad-band spectral energy distribution decomposition to disentangle the possible active galactic nucleus (AGN) contribution from that related to the host galaxy. We find that 37 per cent of the Herschel-selected sample shows signatures of nuclear activity at the 99 per cent confidence level. The probability of revealing AGN activity increases for bright (L 1−1000 > 10 11 L ? ) star-forming galaxies at z > 0.3, becoming about 80 per cent for the brightest (L 1−1000 > 10 12 L ? ) Infrared (IR) galaxies at z≥1. Finally, we reconstruct the AGN bolometric luminosity function and the supermassive black hole growth rate across cosmic time up to z ∼ 3 from a far-IR perspective. This work shows general agreement with most of the panchromatic estimates from the literature, with the global black hole growth peaking at z ∼ 2 and reproducing the observed local black hole mass density with consistent values of the radiative efficiency Erad (∼0.07)

Black hole accretion and host galaxies of obscured quasars in XMM-COSMOS

We explore the connection between black hole growth at the center of obscured quasars selected from the XMM-COSMOS survey and the physical properties of their host galaxies. We study a bolometric regime ( 8 x 10^45 erg/s) where several theoretical models invoke major galaxy mergers as the main fueling channel for black hole accretion. We confirm that obscured quasars mainly reside in massive galaxies (Mstar>10^10 Msun) and that the fraction of galaxies hosting such powerful quasars monotonically increases with the stellar mass. We stress the limitation of the use of rest-frame color-magnitude diagrams as a diagnostic tool for studying galaxy evolution and inferring the influence that AGN activity can have on such a process. We instead use the correlation between star-formation rate and stellar mass found for star-forming galaxies to discuss the physical properties of the hosts. We find that at z ~1, ~62% of Type-2 QSOs hosts are actively forming stars and that their rates are comparable to those measured for normal star-forming galaxies. The fraction of star-forming hosts increases with redshift: ~71% at z ~2, and 100% at z ~3. We also find that the the evolution from z ~1 to z ~3 of the specific star-formation rate of the Type-2 QSO hosts is in excellent agreement with that measured for star-forming galaxies. From the morphological analysis, we conclude that most of the objects are bulge-dominated galaxies, and that only a few of them exhibit signs of recent mergers or disks. Finally, bulge-dominated galaxies tend to host Type-2 QSOs with low Eddington ratios (lambda<0.1), while disk-dominated or merging galaxies have at their centers BHs accreting at high Eddington ratios (lambda > 0.1).Comment: Accepted by A&A. 20 pages, 16 figures, 2 tables. A version with higher resolution figures and SED fits of Appendix A is available at http://www.eso.org/~vmainier/QSO2/qso2.pd

Antagomir-17-5p Abolishes the Growth of Therapy-Resistant Neuroblastoma through p21 and BIM

We identified a key oncogenic pathway underlying neuroblastoma progression: specifically, MYCN, expressed at elevated level, transactivates the miRNA 17-5p-92 cluster, which inhibits p21 and BIM translation by interaction with their mRNA 3′ UTRs. Overexpression of miRNA 17-5p-92 cluster in MYCN-not-amplified neuroblastoma cells strongly augments their in vitro and in vivo tumorigenesis. In vitro or in vivo treatment with antagomir-17-5p abolishes the growth of MYCN-amplified and therapy-resistant neuroblastoma through p21 and BIM upmodulation, leading to cell cycling blockade and activation of apoptosis, respectively. In primary neuroblastoma, the majority of cases show a rise of miR-17-5p level leading to p21 downmodulation, which is particularly severe in patients with MYCN amplification and poor prognosis. Altogether, our studies demonstrate for the first time that antagomir treatment can abolish tumor growth in vivo, specifically in therapy-resistant neuroblastoma

Cost impact of procalcitonin-guided decision making on duration of antibiotic therapy for suspected early-onset sepsis in neonates

Abstract Backgrounds The large, international, randomized controlled NeoPInS trial showed that procalcitonin (PCT)-guided decision making was superior to standard care in reducing the duration of antibiotic therapy and hospitalization in neonates suspected of early-onset sepsis (EOS), without increased adverse events. This study aimed to perform a cost-minimization study of the NeoPInS trial, comparing health care costs of standard care and PCT-guided decision making based on the NeoPInS algorithm, and to analyze subgroups based on country, risk category and gestational age. Methods Data from the NeoPInS trial in neonates born after 34 weeks of gestational age with suspected EOS in the first 72 h of life requiring antibiotic therapy were used. We performed a cost-minimization study of health care costs, comparing standard care to PCT-guided decision making. Results In total, 1489 neonates were included in the study, of which 754 were treated according to PCT-guided decision making and 735 received standard care. Mean health care costs of PCT-guided decision making were not significantly different from costs of standard care (€3649 vs. €3616). Considering subgroups, we found a significant reduction in health care costs of PCT-guided decision making for risk category ‘infection unlikely’ and for gestational age ≥ 37 weeks in the Netherlands, Switzerland and the Czech Republic, and for gestational age < 37 weeks in the Czech Republic. Conclusions Health care costs of PCT-guided decision making of term and late-preterm neonates with suspected EOS are not significantly different from costs of standard care. Significant cost reduction was found for risk category ‘infection unlikely,’ and is affected by both the price of PCT-testing and (prolonged) hospitalization due to SAEs

A strongly star-forming group: three massive galaxies associated with a quasi-stellar object

We present here photometric redshift confirmation of the presence of large-scale structure around the z= 1.82 quasi-stellar object (QSO) RX J0941, which shows an overdensity of submillimetre (submm) sources. Radio imaging confirms the presence of the submm sources and pinpoints their likely optical near-infrared (NIR) counterparts. Four of the five submm sources present in this field (including the QSO) have counterparts with redshifts compatible with z= 1.82. We show that our photometric redshifts are robust against the use of different spectral templates. We have measured the galaxy stellar mass of the submm galaxies from their rest-frame K-band luminosity obtaining log(M*/M⊙) ∼ 11.5 ± 0.2, slightly larger than the Schechter mass of present-day galaxies, and hence indicating that most of the stellar mass is already formed. We present optical-to-radio spectral energy distributions (SEDs) of the five Submillimetre Common-User Bolometer Array (SCUBA) sources. The emission of RX J0941 is dominated by reprocessed active galactic nucleus (AGN) emission in the observed mid-IR (MIR) range, while the starburst contribution completely dominates in the submm range. The SEDs of the other three counterparts are compatible with a dominant starburst contribution above ∼24 μm, with star formation rates ∼2000 M⊙ yr−1, central dust masses log(Mdust/M⊙) ∼ 9 ± 0.5 and hence central gas masses log(Mgas/M⊙) ∼ 10.7. There is very little room for an AGN contribution. From X-ray upper limits and the observed 24 μm flux, we derive a maximum 2–10 keV X-ray luminosity of 1044 erg s−1 for any putative AGN, even if they are heavily obscured. This in turn points to relatively small black holes with log(M•/M⊙) ≲ 8 and hence stellar-to-black hole mass ratios about 1 order of magnitude higher than those observed in the present Universe: most of their central black hole masses are still to be accreted. Local stellar-to-black hole mass ratios can be reached if ∼1.3 per cent of the available nuclear gas mass is accreted

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Enhanced star formation rates in AGN hosts with respect to inactive galaxies from PEP-Herschel observations

We compare the average star formation (SF) activity in X-ray selected AGN hosts with mass-matched control inactive galaxies,including star forming and quiescent sources, at 0.5<z<2.5. Recent observations carried out by PACS, the 60-210um Herschel photometric camera, in GOODS-S, GOODS-N and COSMOS allow us to unbiasedly estimate the far-IR luminosity, and hence the SF properties, of the two samples. Accurate AGN host stellar masses are measured by decomposing their total emission into the stellar and nuclear components. We find a higher average SF activity in AGN hosts with respect to non-AGNs. The level of SF enhancement is modest (~0.26dex at ~3sigma) at low X-ray luminosities (Lx10sigma) for bright AGNs. However, when comparing to star forming galaxies only, AGN hosts are broadly consistent with the locus of their `main sequence'. We investigate the relative far-IR luminosity distributions of active and inactive galaxies, and find a higher fraction of PACS detected, hence normal and highly star forming systems among AGN hosts. Although different interpretations are possible, we explain our findings as a consequence of a twofold AGN growth path: faint AGNs evolve through secular processes, with instantaneous AGN accretion not tightly linked to the current total SF in the host, while luminous AGNs co-evolve with their hosts through periods of enhanced AGN activity and SF, possibly through major mergers. While an increased SF with respect to non-AGNs of similar mass is expected in the latter, we interpret the modest SF offsets measured in low-Lx AGN hosts as either a) generated by non-synchronous accretion and SF histories in a merger scenario or b) due to possible connections between instantaneous SF and accretion that can be induced by smaller scale (non-major merger) mechanisms. Far-IR luminosity distributions favour the latter scenario.Comment: Final versio