Search

We cross-match and compare characteristics of galaxy clusters identified in observations from two sky surveys using two completely different techniques. One sample is optically selected from the analysis of three years of Dark Energy Survey observations using the redMaPPer cluster detection algorithm. The second is X-ray selected from XMM observations analysed by the XMM Cluster Survey. The samples comprise a total area of 57.4 deg$^2$, bounded by the area of 4 contiguous XMM survey regions that overlap the DES footprint. We find that the X-ray selected sample is fully matched with entries in the redMaPPer catalogue, above $\lambda>$20 and within 0.1$< z, Comment: Accepted for publication to MNRAS

Signaling between the endoplasmic reticulum (ER) and mitochondria regulates a number of fundamental physiological processes. This signaling involves close physical contacts between the two organelles that are mediated by the VAPB-PTPIP51 ″tethering" proteins. The VAPB-PTPIP51 tethers facilitate inositol 1,4,5-trisphosphate (IP3) receptor delivery of Ca

In this paper we present the X-ray analysis of SDSS DR8 redMaPPer (SDSSRM) clusters using data products from the $XMM$ Cluster Survey (XCS). In total, 1189 SDSSRM clusters fall within the $XMM$-Newton footprint. This has yielded 456 confirmed detections accompanied by X-ray luminosity ($L_{X}$) measurements. Of the detected clusters, 382 have an associated X-ray temperature measurement ($T_{X}$). This represents one of the largest samples of coherently derived cluster $T_{X}$ values to date. Our analysis of the X-ray observable to richness ($\lambda$) scaling relations has demonstrated that scatter in the $T_{X}-\lambda$ relation is roughly a third of that in the $L_{X}-\lambda$ relation, and that the $L_{X}-\lambda$ scatter is intrinsic, i.e. will not be significantly reduced with larger sample sizes. Our analysis of the scaling relation between $L_{X}$ and $T_{X}$ has shown that the fits are sensitive to the selection method of the sample, i.e. whether the sample is made up of clusters detected "serendipitously" compared to those deliberately targeted by $XMM$. These differences are also seen in the $L_{X}-\lambda$ relation and, to a lesser extent, in the $T_{X}-\lambda$ relation. Exclusion of the emission from the cluster core does not make a significant impact to the findings. A combination of selection biases is a likely, but as yet unproven, reason for these differences. Finally, we have also used our data to probe recent claims of anisotropy in the $L_{X}-T_{X}$ relation across the sky. We find no evidence of anistropy, but stress that this may be masked in our analysis by the incomplete declination coverage of the SDSS DR8 sample., Comment: 23 pages, 20 figures, Accepted for publication to MNRAS

Hexanucleotide repeat expansions in C9orf72 are the most common cause of familial amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The mechanisms by which the expansions cause disease are not properly understood but a favoured route involves its translation into dipeptide repeat (DPR) polypeptides, some of which are neurotoxic. However, the precise targets for mutant C9orf72 and DPR toxicity are not fully clear, and damage to several neuronal functions has been described. Many of these functions are regulated by signalling between the endoplasmic reticulum (ER) and mitochondria. ER-mitochondria signalling requires close physical contacts between the two organelles that are mediated by the VAPB-PTPIP51 'tethering' proteins. Here, we show that ER-mitochondria signalling and the VAPB-PTPIP51 tethers are disrupted in neurons derived from induced pluripotent stem (iPS) cells from patients carrying ALS/FTD pathogenic C9orf72 expansions and in affected neurons in mutant C9orf72 transgenic mice. In these mice, disruption of the VAPB-PTPIP51 tethers occurs prior to disease onset suggesting that it contributes to the pathogenic process. We also show that neurotoxic DPRs disrupt the VAPB-PTPIP51 interaction and ER-mitochondria contacts and that this may involve activation of glycogen synthase kinases-3β (GSK3β), a known negative regulator of VAPB-PTPIP51 binding. Finally, we show that these DPRs disrupt delivery of Ca2+ from ER stores to mitochondria, which is a primary function of the VAPB-PTPIP51 tethers. This delivery regulates a number of key neuronal functions that are damaged in ALS/FTD including bioenergetics, autophagy and synaptic function. Our findings reveal a new molecular target for mutant C9orf72-mediated toxicity.

This paper presents results of an impact evaluation of Teen Council, a program that trains youth as peer educators. Teen Council is designed to help peer educators make healthy sexual and reproductive decisions, increase their confidence and abilities to educate their peers and inspire them to advocate for just sexual policies. The program’s impact on these educators was evaluated using a randomized controlled trial. Over 5 years, interested high school students in seven states were randomly assigned to a study condition. An intent-to-treat framework using ordinary least square (OLS) regression was employed to measure program effects. Relative to control, Teen Council youth showed enhanced comfort with their own sexuality, greater comfort with and more frequent communication with parents about sexuality and more positive sexual health behaviors, including accessing reproductive health care and adopting more effective means of contraception. Teen Council youth also reported greater confidence in talking with peers about sexuality and more confidence in their civic engagement skills.

In the COVID-19 pandemic, patients who are older and residents of long-term care facilities (LTCF) are at greatest risk of worse clinical outcomes. We reviewed discharge criteria for hospitalised COVID-19 patients from 10 countries with the highest incidence of COVID-19 cases as of 26 July 2020. Five countries (Brazil, Mexico, Peru, Chile and Iran) had no discharge criteria; the remaining five (USA, India, Russia, South Africa and the UK) had discharge guidelines with large inter-country variability. India and Russia recommend discharge for a clinically recovered patient with two negative reverse transcription polymerase chain reaction (RT-PCR) tests 24 h apart; the USA offers either a symptom based strategy—clinical recovery and 10 days after symptom onset, or the same test-based strategy. The UK suggests that patients can be discharged when patients have clinically recovered; South Africa recommends discharge 14 days after symptom onset if clinically stable. We recommend a unified, simpler discharge criteria, based on current studies which suggest that most SARS-CoV-2 loses its infectivity by 10 days post-symptom onset. In asymptomatic cases, this can be taken as 10 days after the first positive PCR result. Additional days of isolation beyond this should be left to the discretion of individual clinician. This represents a practical compromise between unnecessarily prolonged admissions and returning highly infectious patients back to their care facilities, and is of particular importance in older patients discharged to LTCFs, residents of which may be at greatest risk of transmission and worse clinical outcomes.

When the Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS-REx) spacecraft collected a sample of surface material from asteroid Bennu in 2020 October, it was the first time that an autonomous optical navigation system relying on natural terrain features had been used to guide a spacecraft to a planetary surface. This system, called Natural Feature Tracking (NFT), works by rendering features from digital terrain models and then correlating them with the terrain in real-time navigation images to estimate the spacecraft's position and velocity with respect to the asteroid. Here we describe how the OSIRIS-REx mission built the catalog of features for NFT and how those features performed during rehearsals for and execution of the Touch-and-Go (TAG) sample collection event. Feature performance (quality and accuracy of match) in the rendering and correlation process is the basis of the NFT measurement. All features scored well above the minimum correlation threshold thanks to the effort invested in selecting and modeling them. Residuals across the TAG trajectory were small, indicating that features in the catalog were defined consistently relative to each other. NFT delivered the spacecraft to within 1 m of the targeted location, with a difference of only 3.5 cm and 1.4 s from the predicted location and time of touch. This exceptional performance was crucial for spacecraft safety given Bennu's rough and hazardous terrain.

The OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer) spacecraft collected a sample from the asteroid Bennu in 2020. This achievement leveraged an autonomous optical navigation approach called Natural Feature Tracking (NFT). NFT provided spacecraft state updates by correlating asteroid surface features rendered from previously acquired terrain data with images taken by the onboard navigation camera. The success of NFT was the culmination of years of preparation and collaboration to ensure that feature data would meet navigation requirements. This paper presents the findings from ground testing performed prior to the spacecraft's arrival at Bennu, in which synthetic data were used to develop and validate the technical approach for building NFT features. Correlation sensitivity testing using synthetic models of Bennu enabled the team to characterize the terrain properties that worked well for feature correlation, the challenges posed by smoother terrain, and the impact of imaging conditions on correlation performance. The team found that models constructed from image data by means of stereophotoclinometry (SPC) worked better than those constructed from laser altimetry data, except when test image pixel sizes were more than a factor of 2 smaller than those of the images used for SPC, and when topography was underrepresented and resulted in incorrect shadows in rendered features. Degradation of laser altimetry data related to noise and spatial sampling also led to poor correlation performance. Albedo variation was found to be a key contributor to correlation performance; topographic data alone were insufficient for NFT.

The Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS-REx) mission rendezvoused with asteroid (101955) Bennu in 2018 with the primary objective of collecting a sample of regolith from the surface. As the first NASA asteroid sample return mission, OSIRIS-REx deployed several new technologies to achieve program objectives. Here we present an overview of Natural Feature Tracking (NFT), a system developed to autonomously guide the spacecraft to the desired sampling site using optical navigation and the natural terrain on the surface of Bennu. NFT utilized a series of image-based digital terrain models (DTMs) constructed by means of stereophotoclinometry to represent patches on the surface of the asteroid. These DTMs were used to generate synthetic renderings of the terrain and identify features for use in navigating to the sampling location. In addition, high-resolution models of the sampling site constructed from scanning lidar data were used for predicting the time and location of contact with the surface. These models went through a series of validation tests to ensure the performance of the NFT system. When the spacecraft executed the sampling trajectory in 2020 October, NFT enabled real-time guidance updates that delivered it safely to the desired sampling location while also providing critical hazard avoidance capabilities in the rocky Bennu environment.

Aims The East Midlands Clinical Senate is one of twelve regional clinical senates. Clinical senates act as a forum of multi-professional clinical leaders who can offer independent and objective clinical advice to support commissioners and other stakeholders to make the best decisions about health care for their local populations. The East Midlands Clinical Senate recognised this would provide a unique opportunity to recruit clinical research fellows, creating the opportunity to support leadership development and enhance our ability to produce high quality research to support evidence-based decision making among health and social care leaders. Methods A competitive recruitment process engaged six clinical fellows from a variety of specialties, for one session a week over a 12 month period. The clinical fellows were given the opportunity to work with senior leaders to develop their skills in leadership, strategy, project management and health policy. The fellows were exposed to the full spectrum of clinical senate work, clinical reviews, proactive projects, production and presentation of reports, as well as opportunities to attend meetings with senior leaders both locally and nationally. Conclusions The clinical fellows enhanced the senate work programme by undertaking proactive projects. This allowed collaborative working with partner organisations, to evaluate models of care following service reorganisation, review the evidence regarding systems organisation and collaborative working for winter pressures and generate a narrative to bring physical activity as a treatment to the local healthcare agenda. Clinical fellowships offering the level of exposure to the rich opportunities for clinical leadership development that the East Midlands Clinical Senate has been able to offer are rare. Clinical senates provide innovative arenas for fellows to experience systems based thinking with tangible involvement as leadership figures and supporting leadership career development.

Aims Unprecedented winter pressures in 2017–18 led to cancellations of elective activity across the NHS and deteriorating population outcomes. East Midlands Clinical Senate undertook a review of the local planning processes to manage periods of increased demand Methods A two-stage approach was adopted: Literature review of national guidance Interviews with four local organisations Conclusion 25 papers were identified with guidance falling within 8 key themes: patient flow (n=13), communication and collaboration (13), demand (13), system capacity (12), funding (6), planning (6), patient safety (3) and staff training (3) The interviews revealed that despite similar system and operational challenges, clinical solutions are not being shared between commissioners and providers at scale More collaborative systems leadership approaches from commissioners during winter 2018–19 resulted in improved outcomes across the system The ambulance service is uniquely placed as a provider which interacts daily across local systems and with providers. This enables operational and clinical relationships to be developed and there was evidence of how a strategic approach to learning and responding to this insight had enabled better performance and outcomes following the winter of 2017–18 The importance of looking after workforce and creating the best possible conditions for staff to do their best for patients was highlighted Recommendations Better sharing of data and practices across the region Systems embrace and develop innovative ways of working to facilitate holistic care Commissioners should consider acting more as facilitators (enable change to occur and issues to be tackled) rather than regulators (seeking assurances on what has already happened) Develop better relationships with ambulance services to ensure practices are robust and standardised Improvements in rotas and increased investment in staff (both in terms of staffing numbers and improved skillset of each staff member)

We study the effect of diffuse intracluster light on the critical surface mass density estimated from photometric redshifts of lensing source galaxies, and the resulting bias in a weak lensing measurement of galaxy cluster mass. Under conservative assumptions, we find the bias to be negligible for imaging surveys like the Dark Energy Survey (DES) with a recommended scale cut of >=200 kpc distance from cluster centers. For significantly deeper source catalogs from present and future surveys like the Large Synoptic Survey Telescope (LSST) program, more conservative scale and source magnitude cuts or a correction of the effect may be necessary to achieve per-cent level lensing measurement accuracy, especially at the massive end of the cluster population., 11 pages, 4 figures, matches version published in MNRAS

Using $\sim 100$ X-ray selected clusters in the Dark Energy Survey Science Verification data, we constrain the luminosity function (LF) of cluster red sequence galaxies as a function of redshift. This is the first homogeneous optical/X-ray sample large enough to constrain the evolution of the luminosity function simultaneously in redshift ($0.1, Comment: Updated to match the accepted version

The center determination of a galaxy cluster from an optical cluster finding algorithm can be offset from theoretical prescriptions or $N$-body definitions of its host halo center. These offsets impact the recovered cluster statistics, affecting both richness measurements and the weak lensing shear profile around the clusters. This paper models the centering performance of the \RM~cluster finding algorithm using archival X-ray observations of \RM-selected clusters. Assuming the X-ray emission peaks as the fiducial halo centers, and through analyzing their offsets to the \RM~centers, we find that $\sim 75\pm 8 \%$ of the \RM~clusters are well centered and the mis-centered offset follows a Gamma distribution in normalized, projected distance. These mis-centering offsets cause a systematic underestimation of cluster richness relative to the well-centered clusters, for which we propose a descriptive model. Our results enable the DES Y1 cluster cosmology analysis by characterizing the necessary corrections to both the weak lensing and richness abundance functions of the DES Y1 redMaPPer cluster catalog., Code used in this analysis is available from https://github.com/yyzhang/center_modeling_y1

Angus, C. R., et al. (DES Collaboration), We present a sample of 21 hydrogen-free superluminous supernovae (SLSNe-I) and one hydrogen-rich SLSN (SLSN-II) detected during the five-year Dark Energy Survey (DES). These SNe, located in the redshift range 0.220 < z < 1.998, represent the largest homogeneously selected sample of SLSN events at high redshift. We present the observed g, r, i, z light curves for these SNe, which we interpolate using Gaussian processes. The resulting light curves are analysed to determine the luminosity function of SLSNe-I, and their evolutionary timescales. The DES SLSN-I sample significantly broadens the distribution of SLSN-I light-curve properties when combined with existing samples from the literature. We fit a magnetar model to our SLSNe, and find that this model alone is unable to replicate the behaviour of many of the bolometric light curves. We search the DES SLSN-I light curves for the presence of initial peaks prior to the main light-curve peak. Using a shock breakout model, our Monte Carlo search finds that 3 of our 14 events with pre-max data display such initial peaks. However, 10 events show no evidence for such peaks, in some cases down to an absolute magnitude of, The DES data management system is supported by the National Science Foundation under Grant Numbers AST-1138766 and AST-1536171. The DES participants from Spanish institutions are partially supported by MINECO under grants AYA2015-71825,ESP2015-66861,FPA2015-68048,SEV-2016-0588,SEV-2016-0597, and MDM-2015-0509, some of which include ERDF funds from the European Union. IFAE is partially funded by the CERCA programme of the Generalitat de Catalunya. Research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Program (FP7/2007-2013) including ERC grant agreements 240672, 291329, and 306478. We acknowledge support from the Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO), through project number CE110001020, and the Brazilian Instituto Nacional de Ciência e Tecnologia (INCT) e-Universe (CNPq grant 465376/2014-2).

We search Dark Energy Survey (DES) Year 3 imaging data for galaxy-galaxy strong gravitational lenses using convolutional neural networks. We generate 250,000 simulated lenses at redshifts > 0.8 from which we create a data set for training the neural networks with realistic seeing, sky and shot noise. Using the simulations as a guide, we build a catalogue of 1.1 million DES sources with 1.8 < g - i < 5, 0.6 < g -r < 3, r_mag > 19, g_mag > 20 and i_mag > 18.2. We train two ensembles of neural networks on training sets consisting of simulated lenses, simulated non-lenses, and real sources. We use the neural networks to score images of each of the sources in our catalogue with a value from 0 to 1, and select those with scores greater than a chosen threshold for visual inspection, resulting in a candidate set of 7,301 galaxies. During visual inspection we rate 84 as "probably" or "definitely" lenses. Four of these are previously known lenses or lens candidates. We inspect a further 9,428 candidates with a different score threshold, and identify four new candidates. We present 84 new strong lens candidates, selected after a few hours of visual inspection by astronomers. This catalogue contains a comparable number of high-redshift lenses to that predicted by simulations. Based on simulations we estimate our sample to contain most discoverable lenses in this imaging and at this redshift range., Accepted for publication in MNRAS

We use cosmic microwave background (CMB) temperature maps from the 500 deg$^{2}$ SPTpol survey to measure the stacked lensing convergence of galaxy clusters from the Dark Energy Survey (DES) Year-3 redMaPPer (RM) cluster catalog. The lensing signal is extracted through a modified quadratic estimator designed to be unbiased by the thermal Sunyaev-Zel{'}dovich (tSZ) effect. The modified estimator uses a tSZ-free map, constructed from the SPTpol 95 and 150 GHz datasets, to estimate the background CMB gradient. For lensing reconstruction, we employ two versions of the RM catalog: a flux-limited sample containing 4003 clusters and a volume-limited sample with 1741 clusters. We detect lensing at a significance of 8.7$\sigma$(6.7$\sigma$) with the flux(volume)-limited sample. By modeling the reconstructed convergence using the Navarro-Frenk-White profile, we find the average lensing masses to be $M_{200m}$ = ($1.62^{+0.32}_{-0.25}$ [stat.] $\pm$ 0.04 [sys.]) and ($1.28^{+0.14}_{-0.18}$ [stat.] $\pm$ 0.03 [sys.]) $\times\ 10^{14}\ M_{\odot}$ for the volume- and flux-limited samples respectively. The systematic error budget is much smaller than the statistical uncertainty and is dominated by the uncertainties in the RM cluster centroids. We use the volume-limited sample to calibrate the normalization of the mass-richness scaling relation, and find a result consistent with the galaxy weak-lensing measurements from DES (Mcclintock et al. 2018)., Comment: 19 pages, 6 figures, published in ApJ

Black hole mass measurements outside the local universe are critically important to derive the growth of supermassive black holes over cosmic time, and to study the interplay between black hole growth and galaxy evolution. In this paper we present two measurements of supermassive black hole masses from reverberation mapping (RM) of the broad CIV emission line. These measurements are based on multi-year photometry and spectroscopy from the Dark Energy Survey Supernova Program (DES-SN) and the Australian Dark Energy Survey (OzDES), which together constitute the OzDES RM Program. The observed reverberation lag between the DES continuum photometry and the OzDES emission-line fluxes is measured to be $358^{+126}_{-123}$ and $343^{+58}_{-84}$ days for two quasars at redshifts of $1.905$ and $2.593$ respectively. The corresponding masses of the two supermassive black holes are $4.4 \times 10^{9}$ and $3.3 \times 10^{9}$ M$_\odot$, which are among the highest-redshift and highest-mass black holes measured to date with RM studies. We use these new measurements to better determine the CIV radius$-$luminosity relationship for high-luminosity quasars, which is fundamental to many quasar black hole mass estimates and demographic studies., 15 pages, 12 figures Updated with minor revisions to match version accepted for publication by MNRAS. Results remain the same

© 2019. The American Astronomical Society. All rights reserved.. We present the analysis underpinning the measurement of cosmological parameters from 207 spectroscopically classified SNe Ia from the first 3 years of the Dark Energy Survey Supernova Program (DES-SN), spanning a redshift range of 0.017 < z < 0.849. We combine the DES-SN sample with an external sample of 122 low-redshift (z < 0.1) SNe Ia, resulting in a "DES-SN3YR" sample of 329 SNe Ia. Our cosmological analyses are blinded: after combining our DES-SN3YR distances with constraints from the Cosmic Microwave Background, our uncertainties in the measurement of the dark energy equation-of-state parameter, w, are 0.042 (stat) and 0.059 (stat+syst) at 68% confidence. We provide a detailed systematic uncertainty budget, which has nearly equal contributions from photometric calibration, astrophysical bias corrections, and instrumental bias corrections. We also include several new sources of systematic uncertainty. While our sample is less than one-third the size of the Pantheon sample, our constraints on w are only larger by 1.4×, showing the impact of the DES-SN Ia light-curve quality. We find that the traditional stretch and color standardization parameters of the DES-SNe Ia are in agreement with earlier SN Ia samples such as Pan-STARRS1 and the Supernova Legacy Survey. However, we find smaller intrinsic scatter about the Hubble diagram (0.077 mag). Interestingly, we find no evidence for a Hubble residual step (0.007 ± 0.018 mag) as a function of host-galaxy mass for the DES subset, in 2.4σ tension with previous measurements. We also present novel validation methods of our sample using simulated SNe Ia inserted in DECam images and using large catalog-level simulations to test for biases in our analysis pipelines.

Correlations between tracers of the matter density field and gravitational lensing are sensitive to the evolution of the matter power spectrum and the expansion rate across cosmic time. Appropriately defined ratios of such correlation functions, on the other hand, depend only on the angular diameter distances to the tracer objects and to the gravitational lensing source planes. Because of their simple cosmological dependence, such ratios can exploit available signal-to-noise down to small angular scales, even where directly modeling the correlation functions is difficult. We present a measurement of lensing ratios using galaxy position and lensing data from the Dark Energy Survey, and CMB lensing data from the South Pole Telescope and Planck, obtaining the highest precision lensing ratio measurements to date. Relative to the concordance $\Lambda$CDM model, we find a best fit lensing ratio amplitude of $A = 1.1 \pm 0.1$. We use the ratio measurements to generate cosmological constraints, focusing on the curvature parameter. We demonstrate that photometrically selected galaxies can be used to measure lensing ratios, and argue that future lensing ratio measurements with data from a combination of LSST and Stage-4 CMB experiments can be used to place interesting cosmological constraints, even after considering the systematic uncertainties associated with photometric redshift and galaxy shear estimation., Comment: 17 pages, 11 figures

Using data collected by the Dark Energy Survey (DES), we report the detection of intracluster light (ICL) with $\sim300$ galaxy clusters in the redshift range of 0.2-0.3. We design methods to mask detected galaxies and stars in the images and stack the cluster light profiles, while accounting for several systematic effects (sky subtraction, instrumental point-spread function, cluster selection effects and residual light in the ICL raw detection from background and cluster galaxies). The methods allow us to acquire high signal-to-noise measurements of the ICL and central galaxies (CGs), which we separate with radial cuts. The ICL appears as faint and diffuse light extending to at least 1 Mpc from the cluster center, reaching a surface brightness level of 30 mag arcsec$^{-2}$. The ICL and the cluster CG contribute to $44\%\pm17$\% of the total cluster stellar luminosity within 1 Mpc. The ICL color is overall consistent with that of the cluster red sequence galaxies, but displays the trend of becoming bluer with increasing radius. The ICL demonstrates an interesting self-similarity feature -- for clusters in different richness ranges, their ICL radial profiles are similar after scaling with cluster $R_\mathrm{200m}$, and the ICL brightness appears to be a good tracer of the cluster radial mass distribution. These analyses are based on the DES redMaPPer cluster sample identified in the first year of observations., Revised to match the published version. Paper data available from https://des.ncsa.illinois.edu/releases/other/paper-data

We define and characterise a sample of 1.3 million galaxies extracted from the first year of Dark Energy Survey data, optimised to measure Baryon Acoustic Oscillations in the presence of significant redshift uncertainties. The sample is dominated by luminous red galaxies located at redshifts $z \gtrsim 0.6$. We define the exact selection using color and magnitude cuts that balance the need of high number densities and small photometric redshift uncertainties, using the corresponding forecasted BAO distance error as a figure-of-merit in the process. The typical photo-$z$ uncertainty varies from $2.3\%$ to $3.6\%$ (in units of 1+$z$) from $z=0.6$ to $1$, with number densities from $200$ to $130$ galaxies per deg$^2$ in tomographic bins of width $\Delta z = 0.1$. Next we summarise the validation of the photometric redshift estimation. We characterise and mitigate observational systematics including stellar contamination, and show that the clustering on large scales is robust in front of those contaminants. We show that the clustering signal in the auto-correlations and cross-correlations is generally consistent with theoretical models, which serves as an additional test of the redshift distributions., Comment: 15 pages, 12 figures. Added discussion on photo-z validation and other tests added based on referee's comments. Matches published version in MNRAS

We present a chemical abundance analysis of four additional confirmed member stars of Tucana III, a Milky Way satellite galaxy candidate in the process of being tidally disrupted as it is accreted by the Galaxy. Two of these stars are centrally located in the core of the galaxy while the other two stars are located in the eastern and western tidal tails. The four stars have chemical abundance patterns consistent with the one previously studied star in Tucana III: they are moderately enhanced in $r$-process elements, i.e. they have $ \approx +$0.4 dex. The non-neutron-capture elements generally follow trends seen in other dwarf galaxies, including a metallicity range of 0.44 dex and the expected trend in $\alpha$-elements, i.e., the lower metallicity stars have higher Ca and Ti abundance. Overall, the chemical abundance patterns of these stars suggest that Tucana III was an ultra-faint dwarf galaxy, and not a globular cluster, before being tidally disturbed. As is the case for the one other galaxy dominated by $r$-process enhanced stars, Reticulum II, Tucana III's stellar chemical abundances are consistent with pollution from ejecta produced by a binary neutron star merger, although a different $r$-process element or dilution gas mass is required to explain the abundances in these two galaxies if a neutron star merger is the sole source of $r$-process enhancement., Comment: 18 pages, 10 figures; accepted by ApJ

The largest structures in the cosmic web probe the dynamical nature of dark energy through their integrated Sachs-Wolfe imprints. In the strength of the signal, typical cosmic voids have shown good consistency with expectation $A_{\rm ISW}=\Delta T^{\rm data} / \Delta T^{\rm theory}=1$, given the substantial cosmic variance. Discordantly, large-scale hills in the gravitational potential, or supervoids, have shown excess signals. In this study, we mapped out 87 new supervoids in the total 5000 deg$^2$ footprint of the Dark Energy Survey at $0.2, Comment: 13 pages, 5 figures, accepted MNRAS (minor revision)

We describe the first public data release of the Dark Energy Survey, DES DR1, consisting of reduced single epoch images, coadded images, coadded source catalogs, and associated products and services assembled over the first three years of DES science operations. DES DR1 is based on optical/near-infrared imaging from 345 distinct nights (August 2013 to February 2016) by the Dark Energy Camera mounted on the 4-m Blanco telescope at Cerro Tololo Inter-American Observatory in Chile. We release data from the DES wide-area survey covering ~5,000 sq. deg. of the southern Galactic cap in five broad photometric bands, grizY. DES DR1 has a median delivered point-spread function of g = 1.12, r = 0.96, i = 0.88, z = 0.84, and Y = 0.90 arcsec FWHM, a photometric precision of < 1% in all bands, and an astrometric precision of 151 mas. The median coadded catalog depth for a 1.95" diameter aperture at S/N = 10 is g = 24.33, r = 24.08, i = 23.44, z = 22.69, and Y = 21.44 mag. DES DR1 includes nearly 400M distinct astronomical objects detected in ~10,000 coadd tiles of size 0.534 sq. deg. produced from ~39,000 individual exposures. Benchmark galaxy and stellar samples contain ~310M and ~ 80M objects, respectively, following a basic object quality selection. These data are accessible through a range of interfaces, including query web clients, image cutout servers, jupyter notebooks, and an interactive coadd image visualization tool. DES DR1 constitutes the largest photometric data set to date at the achieved depth and photometric precision., 30 pages, 20 Figures. Release page found at this url https://des.ncsa.illinois.edu/releases/dr1

The need for doctors at all levels to undergo some form of leadership development is well evidenced, but provision remains patchy and models underpinning such development are often inconsistent. This article sets out the findings of a literature review into leadership development opportunities for doctors in training in the UK.

We study the methodology and potential theoretical systematics of measuring Baryon Acoustic Oscillations (BAO) using the angular correlation functions in tomographic bins. We calibrate and optimize the pipeline for the Dark Energy Survey Year 1 dataset using 1800 mocks. We compare the BAO fitting results obtained with three estimators: the Maximum Likelihood Estimator (MLE), Profile Likelihood, and Markov Chain Monte Carlo. The fit results from the MLE are the least biased and their derived 1-$\sigma$ error bar are closest to the Gaussian distribution value after removing the extreme mocks with non-detected BAO signal. We show that incorrect assumptions in constructing the template, such as mismatches from the cosmology of the mocks or the underlying photo-$z$ errors, can lead to BAO angular shifts. We find that MLE is the method that best traces this systematic biases, allowing to recover the true angular distance values. In a real survey analysis, it may happen that the final data sample properties are slightly different from those of the mock catalog. We show that the effect on the mock covariance due to the sample differences can be corrected with the help of the Gaussian covariance matrix or more effectively using the eigenmode expansion of the mock covariance. In the eigenmode expansion, the eigenmodes are provided by some proxy covariance matrix. The eigenmode expansion is significantly less susceptible to statistical fluctuations relative to the direct measurements of the covariance matrix because of the number of free parameters is substantially reduced, Comment: 23 pages, 23 figs, match to the published version

We perform a search for stellar streams around the Milky Way using the first three years of multi-band optical imaging data from the Dark Energy Survey (DES). We use DES data covering $\sim 5000$ sq. deg. to a depth of $g > 23.5$ with a relative photometric calibration uncertainty of $< 1 \%$. This data set yields unprecedented sensitivity to the stellar density field in the southern celestial hemisphere, enabling the detection of faint stellar streams to a heliocentric distance of $\sim 50$ kpc. We search for stellar streams using a matched-filter in color-magnitude space derived from a synthetic isochrone of an old, metal-poor stellar population. Our detection technique recovers four previously known thin stellar streams: Phoenix, ATLAS, Tucana III, and a possible extension of Molonglo. In addition, we report the discovery of eleven new stellar streams. In general, the new streams detected by DES are fainter, more distant, and lower surface brightness than streams detected by similar techniques in previous photometric surveys. As a by-product of our stellar stream search, we find evidence for extra-tidal stellar structure associated with four globular clusters: NGC 288, NGC 1261, NGC 1851, and NGC 1904. The ever-growing sample of stellar streams will provide insight into the formation of the Galactic stellar halo, the Milky Way gravitational potential, as well as the large- and small-scale distribution of dark matter around the Milky Way., 32 pages, 6 animations, 19 figures, 4 tables; submitted to ApJ

An increasing number of frail older people are attending emergency departments. Many of these have existing cognitive impairment (e.g. a dementia), whilst for others, there may be an acute confusional state (e.g. delirium). Cognitive impairment is commonly missed in the ED, and this has been associated with poor outcomes. People with frailty and dementia are particularly susceptible to delirium, and this is typically precipitated by additional stressor (e.g. acute illness or a recent change in medications). Cognitive impairment may or may not be the cause of the presentation, but in all cases, it is imperative to consider and screen for the possibility of new (delirium) or existing (dementia) cognitive impairment, paying particular attention to the possibility of coexistence of these conditions. A collateral history from people who know the patient well is imperative and should form part of the routine assessment for frail older people. Screening for cognitive impairment in the ED should use evidence-based tools to identify potential precipitating factors, some of which may be modifiable. The diagnosis of delirium is clinical, and there are no specific investigations although routine investigations may point to potential contributing factors or help to exclude other causes of cognitive impairment. Delirium management is focused on addressing the modifiable contributing factors, and we should refrain from pharmacological interventions unless behaviour poses a significant risk of harm. A calm environment for people with both dementia and delirium is key, and as far as possible, sensory stimuli should be minimised. Reorientation (time, place and person) is a simple, yet important intervention.

Clusters of galaxies gravitationally lens the cosmic microwave background (CMB) radiation, resulting in a distinct imprint in the CMB on arcminute scales. Measurement of this effect offers a promising way to constrain the masses of galaxy clusters, particularly those at high redshift. We use CMB maps from the South Pole Telescope Sunyaev-Zel'dovich (SZ) survey to measure the CMB lensing signal around galaxy clusters identified in optical imaging from first year observations of the Dark Energy Survey. The cluster catalog used in this analysis contains 3697 members with mean redshift of $\bar{z} = 0.45$. We detect lensing of the CMB by the galaxy clusters at $8.1\sigma$ significance. Using the measured lensing signal, we constrain the amplitude of the relation between cluster mass and optical richness to roughly $17\%$ precision, finding good agreement with recent constraints obtained with galaxy lensing. The error budget is dominated by statistical noise but includes significant contributions from systematic biases due to the thermal SZ effect and cluster miscentering., Comment: 16 pages, 5 figures; replaced to match version accepted by MNRAS