We present the analysis of deep X-ray observations of 10 massive galaxy clusters at redshifts \(1.05 < z < 1.71\), with the primary goal of measuring the metallicity of the intracluster medium (ICM) ...at intermediate radii, to better constrain models of the metal enrichment of the intergalactic medium. The targets were selected from X-ray and Sunyaev-Zel'dovich (SZ) effect surveys, and observed with both the \textit{XMM-Newton} and \textit{Chandra} satellites. For each cluster, a precise gas mass profile was extracted, from which the value of \(r_{500}\) could be estimated. This allows us to define consistent radial ranges over which the metallicity measurements can be compared. In general, the data are of sufficient quality to extract meaningful metallicity measurements in two radial bins, \(r<0.3r_{500}\) and \(0.3<r/r_{500}<1.0\). For the outer bin, the combined measurement for all ten clusters, \(Z/Z_{\odot} = 0.21 \pm 0.09\), represents a substantial improvement in precision over previous results. This measurement is consistent with, but slightly lower than, the average metallicity of 0.315 Solar measured at intermediate-to-large radii in low-redshift clusters. Combining our new high-redshift data with the previous low-redshift results allows us to place the tightest constraints to date on models of the evolution of cluster metallicity at intermediate radii. Adopting a power law model of the form \(Z \propto \left(1+z\right)^\gamma\), we measure a slope \(\gamma = -0.5^{+0.4}_{-0.3}\), consistent with the majority of the enrichment of the ICM having occurred at very early times and before massive clusters formed, but leaving open the possibility that some additional enrichment in these regions may have occurred since a redshift of 2.
Many massive early-type galaxies host central radio sources and hot X-ray atmospheres indicating the presence of radio-mechanical active galactic nucleus (AGN) feedback. The duty cycle and detailed ...physics of the radio-mode AGN feedback is still a matter of debate. To address these questions, we present 1-2 GHz Karl G. Jansky Very Large Array (VLA) radio observations of a sample of the 42 nearest optically and X-ray brightest early-type galaxies. We detect radio emission in 41/42 galaxies. However, the galaxy without a radio source, NGC 499, has recently been detected at lower frequencies by the Low-Frequency Array (LOFAR). Furthermore, 27/42 galaxies in our sample host extended radio structures and 34/42 sources show environmental interactions in the form of X-ray cavities. We find a significant correlation between the radio flux density and the largest linear size of the radio emission and between the radio power and the luminosity of the central X-ray point-source. The central radio spectral indices of the galaxies span a wide range of values, with the majority of the systems having steep spectra and the rest flat spectra. These results are consistent with AGN activity, where the central radio sources are mostly switched on, thus the duty cycle is very high. 7/14 galaxies with point-like radio emission (Fanaroff-Riley Class 0; FR 0) also show X-ray cavities indicating that, despite the lack of extended radio structures at 1-2 GHz, these AGN do launch jets capable of inflating lobes and cavities.
Background Data regarding the effects of antenatal corticosteroids in twin pregnancies are limited because of the insufficient number of women with twins enrolled in randomized controlled trials on ...antenatal corticosteroids. Furthermore, the interpretation of available data is limited by the fact that the interval from the administration of antenatal corticosteroids to delivery is greater than 7 days in a large proportion of twins, a factor that has been shown to affect the efficacy of antenatal corticosteroids and has not been controlled for in previous studies. Objective The objective of the study was to compare neonatal mortality and morbidity in preterm twins receiving a complete course of antenatal corticosteroids 1–7 days before birth to those who did not receive antenatal corticosteroids and to compare these outcome effects with those observed in singletons. Study Design We performed a retrospective cohort study using data collected on singleton and twin neonates born between 240/7 and 336/7 weeks’ gestational age and were admitted to tertiary neonatal units in Canada between 2010 and 2014. A comparison of neonatal outcomes between twin neonates who received a complete course of antenatal corticosteroids 1–7 days before birth (n = 1758) and those who did not receive antenatal corticosteroids (n = 758) and between singleton neonates who received a complete course of antenatal corticosteroids 1–7 days before birth (n = 4638) and those did not receive antenatal corticosteroids (n = 2312) was conducted after adjusting for gestational age, sex, hypertension, outborn status, small for gestational age, parity, and cesarean birth. Adjusted odds ratios and 95% confidence intervals for various neonatal outcomes were calculated. Results Administration of a complete course of antenatal corticosteroids within 1–7 days before birth in both twins and singletons was associated with similar reduced odds of neonatal death (for twins adjusted odds ratio 0.42 95% confidence interval, 0.24–0.76 and for singletons adjusted odds ratios, 0.38 95% confidence interval, 0.28–0.50; P = .7 for comparison of twins vs singletons), mechanical ventilation (for twins adjusted odds ratio, 0.47 95% confidence interval, 0.35–0.63 and for singletons adjusted odds ratio, 0.47 95% confidence interval, 0.41–0.55; P = .9), respiratory distress syndrome (for twins adjusted odds ratio, 0.53 95% confidence interval, 0.40–0.69, and for singletons adjusted odds ratio, 0.54 95% confidence interval, 0.47–0.62; P = .9) and severe neurological injury (for twins adjusted odds ratio, 0.50 95% confidence interval, 0.30–0.83 and for singletons adjusted odds ratio, 0.45 95% confidence interval, 0.34–0.59; P = .7). Administration of a complete course of antenatal corticosteroids was not associated with a reduced odds of bronchopulmonary dysplasia, severe retinopathy of prematurity, or necrotizing enterocolitis in both twins and singletons. Conclusion Administration of a complete course of antenatal corticosteroids 1–7 days before birth in twin pregnancies is associated with a clinically significant decrease in neonatal mortality, short-term respiratory morbidity, and severe neurological injury that is similar in magnitude to that observed among singletons.
The PRObabilistic Value-Added Bright Galaxy Survey (PROVABGS) catalog will provide measurements of galaxy properties, such as stellar mass (\(M_*\)), star formation rate (\({\rm SFR}\)), stellar ...metallicity (\(Z_{\rm MW}\)), and stellar age (\(t_{\rm age, MW}\)), for >10 million galaxies of the DESI Bright Galaxy Survey. Full posterior distributions of the galaxy properties will be inferred using state-of-the-art Bayesian spectral energy distribution (SED) modeling of DESI spectroscopy and Legacy Surveys photometry. In this work, we present the SED model, Bayesian inference framework, and methodology of PROVABGS. Furthermore, we apply the PROVABGS SED modeling on realistic synthetic DESI spectra and photometry, constructed using the L-GALAXIES semi-analytic model. We compare the inferred galaxy properties to the true galaxy properties of the simulation using a hierarchical Bayesian framework to quantify accuracy and precision. Overall, we accurately infer the true \(M_*\), \({\rm SFR}\), \(Z_{\rm MW}\), and \(t_{\rm age, MW}\) of the simulated galaxies. However, the priors on galaxy properties induced by the SED model have a significant impact on the posteriors. They impose a \({\rm SFR}{>}10^{-1} M_\odot/{\rm yr}\) lower bound on \({\rm SFR}\), a \({\sim}0.3\) dex bias on \(\log Z_{\rm MW}\) for galaxies with low spectral signal-to-noise, and \(t_{\rm age, MW} < 8\,{\rm Gyr}\) upper bound on stellar age. This work also demonstrates that a joint analysis of spectra and photometry significantly improves the constraints on galaxy properties over photometry alone and is necessary to mitigate the impact of the priors. With the methodology presented and validated in this work, PROVABGS will maximize information extracted from DESI observations and provide a probabilistic value-added galaxy catalog that will extend current galaxy studies to new regimes and unlock cutting-edge probabilistic analyses.
We present updated cosmological constraints from measurements of the gas mass fractions (\(f_{gas}\)) of massive, dynamically relaxed galaxy clusters. Our new data set has greater leverage on models ...of dark energy, thanks to the addition of the Perseus Cluster at low redshifts, two new clusters at redshifts \(z>0.97\), and significantly longer observations of four clusters at \(0.6<z<0.9\). Our low-redshift (\(z<0.16\)) \(f_{gas}\) data, combined with the cosmic baryon fraction measured from the cosmic microwave background (CMB), imply a Hubble constant of \(h = 0.722 \pm 0.067\). Combining the full \(f_{gas}\) data set with priors on the cosmic baryon density and the Hubble constant, we constrain the dark energy density to be \(\Omega_\Lambda = 0.865 \pm 0.119\) in non-flat \(\Lambda\)CDM (cosmological constant) models, and its equation of state to be \(w = -1.13_{-0.20}^{+0.17}\) in flat, constant-w models, respectively 41 and 29 per cent tighter than our previous work, and comparable to the best constraints available from other probes. Combining \(f_{gas}\), CMB, supernova, and baryon acoustic oscillation data, we also constrain models with global curvature and evolving dark energy. For the massive, relaxed clusters employed here, we find the scaling of \(f_{gas}\) with mass to be consistent with a constant, with an intrinsic scatter that corresponds to just 3 per cent in distance.
We have observed the z=4.3 protocluster SPT2349-56 with ATCA with the aim of detecting radio-loud active galactic nuclei (AGN) amongst the ~30 submillimeter galaxies identified in the structure. We ...detect the central complex of SMGs at 2.2\,GHz with a luminosity of L_2.2=(4.42pm0.56)x10^{25} W/Hz. The ASKAP also detects the source at 888 MHz, constraining the radio spectral index to alpha=-1.6pm0.3, consistent with ATCA non-detections at 5.5 and 9GHz, and implying L_1.4(rest)=(2.4pm0.3)x10^{26}W/Hz. This radio luminosity is about 100 times higher than expected from star formation, assuming the usual FIR-radio correlation, which is a clear indication of an AGN driven by a forming brightest cluster galaxy (BCG). None of the SMGs in SPT2349-56 show signs of AGN in any other diagnostics available to us (notably 12CO out to J=16, OH163um, CII/IR, and optical spectra), highlighting the radio continuum as a powerful probe of obscured AGN in high-z protoclusters. No other significant radio detections are found amongst the cluster members, consistent with the FIR-radio correlation. We compare these results to field samples of radio sources and SMGs, along with the 22 SPT-SMG gravitational lenses also observed in the ATCA program, as well as powerful radio galaxies at high redshifts. Our results allow us to better understand the effects of this gas-rich, overdense environment on early supermassive black hole (SMBH) growth and cluster feedback. We estimate that (3.3pm0.7)x10^{38} W of power are injected into the growing ICM by the radio-loud AGN, whose energy over 100Myr is comparable to the binding energy of the gas mass of the central halo. The AGN power is also comparable to the instantaneous energy injection from supernova feedback from the 23 catalogued SMGs in the core region of 120kpc projected radius. The SPT2349-56 radio-loud AGN may be providing strong feedback on a nascent ICM.
We present results from a 577 ks XMM-Newton observation of SPT-CL J0459-4947, the most distant cluster detected in the South Pole Telescope 2500 square degree (SPT-SZ) survey, and currently the most ...distant cluster discovered through its Sunyaev-Zel'dovich effect. The data confirm the cluster's high redshift, \(z=1.71 \pm 0.02\), in agreement with earlier, less precise optical/IR photometric estimates. From the gas density profile, we estimate a characteristic mass of \(M_{500}=(1.8 \pm 0.2) \times 10^{14}M_{Sun}\); cluster emission is detected above the background to a radius of \(\sim 2.2 r_{500}\), or approximately the virial radius. The intracluster gas is characterized by an emission-weighted average temperature of \(7.2 \pm 0.3\) keV and metallicity with respect to Solar of \(0.37 \pm 0.08\). For the first time at such high redshift, this deep data set provides a measurement of metallicity outside the cluster center; at radii \(r > 0.3 r_{500}\), we find it to be \(0.33 \pm 0.17\), in good agreement with precise measurements at similar radii in the most nearby clusters, supporting an early enrichment scenario in which the bulk of the cluster gas is enriched to a universal metallicity prior to cluster formation, with little to no evolution thereafter. The leverage provided by the high redshift of this cluster tightens by a factor of 2 constraints on evolving metallicity models, when combined with previous measurements at lower redshifts.
Evidence suggests that high-density lipoprotein (HDL) components distinct from cholesterol, such as sphingosine-1-phosphate (S1P), may account for the anti-atherothrombotic effects attributed to this ...lipoprotein. The current method for the determination of plasma levels of S1P as well as levels associated with HDL particles is still cumbersome an assay method to be worldwide practical. Recently, a simplified protocol based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the sensitive and specific quantification of plasma levels of S1P with good accuracy has been reported. This work utilized a triple quadrupole (QqQ)-based LC-MS/MS system. Here we adapt that method for the determination of plasma levels of S1P using a quadrupole time of flight (Q-Tof) based LC-MS system. Calibration curves were linear in the range of 0.05 to 2 µM. The lower limit of quantification (LOQ) was 0.05 µM. The concentration of S1P in human plasma was determined to be 1 ± 0.09 µM (
= 6). The average accuracy over the stated range of the method was found to be 100 ± 5.9% with precision at the LOQ better than 10% when predicting the calibration standards. The concentration of plasma S1P in the prepared samples was stable for 24 h at room temperature. We have demonstrated the quantification of plasma S1P using Q-Tof based LC-MS with very good sensitivity, accuracy, and precision that can used for future studies in this field.
Display omitted
The post-transcriptional modifier tRNA-(N1G37) methyltransferase (TrmD) has been proposed to be essential for growth in many Gram-negative and Gram-positive pathogens, however ...previously reported inhibitors show only weak antibacterial activity. In this work, optimisation of fragment hits resulted in compounds with low nanomolar TrmD inhibition incorporating features designed to enhance bacterial permeability and covering a range of physicochemical space. The resulting lack of significant antibacterial activity suggests that whilst TrmD is highly ligandable, its essentiality and druggability are called into question.
Successful management of chronic cough has varied in the primary research studies in the reported literature. One of the potential reasons relates to a lack of intervention fidelity to the core ...elements of the diagnostic and/or therapeutic interventions that were meant to be used by the investigators.
We conducted a systematic review to summarize the evidence supporting intervention fidelity as an important methodologic consideration in assessing the effectiveness of clinical practice guidelines used for the diagnosis and management of chronic cough. We developed and used a tool to assess for five areas of intervention fidelity. Medline (PubMed), Scopus, and the Cochrane Database of Systematic Reviews were searched from January 1998 to May 2014. Guideline recommendations and suggestions for those conducting research using guidelines or protocols to diagnose and manage chronic cough in the adult were developed and voted upon using CHEST Organization methodology.
A total of 23 studies (17 uncontrolled prospective observational, two randomized controlled, and four retrospective observational) met our inclusion criteria. These articles included 3,636 patients. Data could not be pooled for meta-analysis because of heterogeneity. Findings related to the five areas of intervention fidelity included three areas primarily related to the provider and two primarily related to the patients. In the area of study design, 11 of 23 studies appeared to be underpinned by a single guideline/protocol; for training of providers, two of 23 studies reported training, and zero of 23 reported the use of an intervention manual; and for the area of delivery of treatment, when assessing the treatment of gastroesophageal reflux disease, three of 23 studies appeared consistent with the most recent guideline/protocol referenced by the authors. For receipt of treatment, zero of 23 studies mentioned measuring concordance of patient-interventionist understanding of the treatment recommended, and zero of 23 mentioned measuring enactment of treatment, with three of 23 measuring side effects and two of 23 measuring adherence. The overall average intervention fidelity score for all 23 studies was poor (20.74 out of 48).
Only low-quality evidence supports that intervention fidelity strategies were used when conducting primary research in diagnosing and managing chronic cough in adults. This supports the contention that some of the variability in the reporting of patients with unexplained or unresolved chronic cough may be due to lack of intervention fidelity. By following the recommendations and suggestions in this article, researchers will likely be better able to incorporate strategies to address intervention fidelity, thereby strengthening the validity and generalizability of their results that provide the basis for the development of trustworthy guidelines.
PDF
