The tidal remnant of an unusually metal-poor globular cluster.

Globular clusters are some of the oldest bound stellar structures observed in the Universe1. They are ubiquitous in large galaxies and are believed to trace intense star-formation events and the hierarchical build-up of structure2,3. Observations of globular clusters in the Milky Way, and a wide variety of other galaxies, have found evidence for a 'metallicity floor', whereby no globular clusters are found with chemical (metal) abundances below approximately 0.3 to 0.4 per cent of that of the Sun4-6. The existence of this metallicity floor may reflect a minimum mass and a maximum redshift for surviving globular clusters to form-both critical components for understanding the build-up of mass in the Universe7. Here we report measurements from the Southern Stellar Streams Spectroscopic Survey of the spatially thin, dynamically cold Phoenix stellar stream in the halo of the Milky Way. The properties of the Phoenix stream are consistent with it being the tidally disrupted remains of a globular cluster. However, its metal abundance ([Fe/H] = -2.7) is substantially below the empirical metallicity floor. The Phoenix stream thus represents the debris of the most metal-poor globular clusters discovered so far, and its progenitor is distinct from the present-day globular cluster population in the local Universe. Its existence implies that globular clusters below the metallicity floor have probably existed, but were destroyed during Galactic evolution.

Galactic Center Excess in a New Light: Disentangling the γ-Ray Sky with Bayesian Graph Convolutional Neural Networks.

A fundamental question regarding the Galactic Center excess (GCE) is whether the underlying structure is pointlike or smooth, often framed in terms of a millisecond pulsar or annihilating dark matter (DM) origin for the emission. We show that Bayesian neural networks (NNs) have the potential to resolve this debate. In simulated data, the method is able to predict the flux fractions from inner Galaxy emission components to on average ∼0.5%. When applied to the Fermi photon-count map, the NN identifies a smooth GCE in the data, suggestive of the presence of DM, with the estimates for the background templates being consistent with existing results.

Two major accretion epochs in M31 from two distinct populations of globular clusters.

Large galaxies grow through the accumulation of dwarf galaxies1,2. In principle it is possible to trace this growth history via the properties of a galaxy's stellar halo3-5. Previous investigations of the galaxy Messier 31 (M31, Andromeda) have shown that outside a galactocentric radius of 25 kiloparsecs the population of halo globular clusters is rotating in alignment with the stellar disk6,7, as are more centrally located clusters8,9. The M31 halo also contains coherent stellar substructures, along with a smoothly distributed stellar component10-12. Many of the globular clusters outside a radius of 25 kiloparsecs are associated with the most prominent substructures, but some are part of the smooth halo13. Here we report an analysis of the kinematics of these globular clusters. We find two distinct populations rotating perpendicular to each other. The rotation axis for the population associated with the smooth halo is aligned with the rotation axis for the plane of dwarf galaxies14 that encircles M31. We interpret these separate cluster populations as arising from two major accretion epochs, probably separated by billions of years. Stellar substructures from the first epoch are gone, but those from the more recent second epoch still remain.

Quality assurance of the SCOPE 1 trial in oesophageal radiotherapy.

BACKGROUND: SCOPE 1 was the first UK based multi-centre trial involving radiotherapy of the oesophagus. A comprehensive radiotherapy trials quality assurance programme was launched with two main aims: 1. To assist centres, where needed, to adapt their radiotherapy techniques in order to achieve protocol compliance and thereby enable their participation in the trial. 2. To support the trial's clinical outcomes by ensuring the consistent planning and delivery of radiotherapy across all participating centres. METHODS: A detailed information package was provided and centres were required to complete a benchmark case in which the delineated target volumes and organs at risk, dose distribution and completion of a plan assessment form were assessed prior to recruiting patients into the trial. Upon recruiting, the quality assurance (QA) programme continued to monitor the outlining and planning of radiotherapy treatments. Completion of a questionnaire was requested in order to gather information about each centre's equipment and techniques relating to their trial participation and to assess the impact of the trial nationally on standard practice for radiotherapy of the oesophagus. During the trial, advice was available for individual planning issues, and was circulated amongst the SCOPE 1 community in response to common areas of concern using bulletins. RESULTS: 36 centres were supported through QA processes to enable their participation in SCOPE1. We discuss the issues which have arisen throughout this process and present details of the benchmark case solutions, centre questionnaires and on-trial protocol compliance. The range of submitted benchmark case GTV volumes was 29.8-67.8cm3; and PTV volumes 221.9-513.3 cm3. For the dose distributions associated with these volumes, the percentage volume of the lungs receiving 20Gy (V20Gy) ranged from 20.4 to 33.5%. Similarly, heart V40Gy ranged from 16.1 to 33.0%. Incidence of incorrect outlining of OAR volumes increased from 50% of centres at benchmark case, to 64% on trial. Sixty-five percent of centres, who returned the trial questionnaire, stated that their standard practice had changed as a result of their participation in the SCOPE1 trial. CONCLUSIONS: The SCOPE 1 QA programme outcomes lend support to the trial's clinical conclusions. The range of patient planning outcomes for the benchmark case indicated, at the outset of the trial, the significant degree of variation present in UK oesophageal radiotherapy planning outcomes, despite the presence of a protocol. This supports the case for increasingly detailed definition of practice by means of consensus protocols, training and peer review. The incidence of minor inconsistencies of technique highlights the potential for improved QA systems and the need for sufficient resource for this to be addressed within future trials. As indicated in questionnaire responses, the QA exercise as a whole has contributed to greater consistency of oesophageal radiotherapy in the UK via the adoption into standard practice of elements of the protocol. TRIAL REGISTRATION: The SCOPE1 trial is an International Standard Randomized Controlled Trial, ISRCTN47718479 .

Ultracompact Minihalos as Probes of Inflationary Cosmology.

Cosmological inflation generates primordial density perturbations on all scales, including those far too small to contribute to the cosmic microwave background. At these scales, isolated ultracompact minihalos of dark matter can form well before standard structure formation, if the perturbations have sufficient amplitude. Minihalos affect pulsar timing data and are potentially bright sources of gamma rays. The resulting constraints significantly extend the observable window of inflation in the presence of cold dark matter, coupling two of the key problems in modern cosmology.

Prospective review of radiotherapy trials through implementation of standardized multicentre workflow and IT infrastructure.

OBJECTIVE:: We sought to develop a process that would allow us to perform a prospective review of outlining in trials using expert reviewers based in multiple centres. METHODS:: We implemented a specific information technology infrastructure and workflow that could serve all organizations involved in the radiotherapy quality assurance (RTQA) process. RESULTS:: Data were processed and packaged in the computational environment for radiotherapy research (CERR) binary format and securely transmitted to the expert reviewer at the designated remote organization. It was opened and reviewed using the distributed CERR-compiled application, and a standardized report was sent to the respective centre. Centres were expected to correct any unacceptable deviations and resubmit outlining for approval prior to commencing treatment. 75% of reviews were completed and fed back to centres within 3 working days. There were no delays in treatment start date. CONCLUSION:: Our distributed RTQA review approach provides a method of prospective outlining review at multiple centres, without compromising the quality, delaying the start of treatment or the need for significant additional infrastructure resources. Future progress in the area of prospective individual case review will need to be supported by additional resources for clinician time to undertake the reviews. ADVANCES IN KNOWLEDGE:: Trial groups around the world have formulated different approaches to address the need for the prospective review of radiotherapy (RT) data with clinical trials, in line with available resources. We report a UK solution that has allowed the workload for outlining review to be distributed across a wider group of volunteer reviewers without the need for any additional infrastructure costs and has already been adopted within the UK RT trials community.

Which modifiable health risks are associated with changes in productivity costs?

The purpose of this retrospective, longitudinal study was to assess longitudinal associations between modifiable health risks and workplace absenteeism and presenteeism and to estimate lost productivity costs. Across the 4-year study period (2007-2010), 17,089 unique employees from a large US computer manufacturer with a highly technical workforce completed at least 1 health risk assessment. Generalized estimating equation models were used to estimate the mean population-level absenteeism and presenteeism for 11 modifiable health risks and adjust for 9 sociodemographic and employment-related factors. Because patient age was highly correlated with several other variables, the analysis was stratified by age (<45 vs. ≥45 years). For all ages, poor emotional health, inadequate exercise, tobacco use, and having a body mass index (BMI) greater than 35 (all P<.05) were consistently associated with both absenteeism and presenteeism. Having a BMI over 35 and poor emotional health were associated with the largest impact in absenteeism (0.46 days) and presenteeism (4.03 days), respectively. Younger and older workers had similar associations between health risks and presenteeism; however, hypertension, blood sugar, inadequate exercise, and alcohol were associated (P⋜.01) with greater absenteeism among older but not younger workers. The results suggest that productivity loss is strongly related to emotional health and obesity-related health risks (eg, BMI, exercise) but differs by age. These findings could help prioritize preventive health programs offered by employers at their worksite health centers. Given the aging of the US workforce, keeping older workers healthy and productive will be crucial to remaining competitive in the global economy. (Population Health Management 2015;18:30-38).

Effect of a postdischarge virtual ward on readmission or death for high-risk patients: a randomized clinical trial.

IMPORTANCE: Hospital readmissions are common and costly, and no single intervention or bundle of interventions has reliably reduced readmissions. Virtual wards, which use elements of hospital care in the community, have the potential to reduce readmissions, but have not yet been rigorously evaluated. OBJECTIVE: To determine whether a virtual ward-a model of care that uses some of the systems of a hospital ward to provide interprofessional care for community-dwelling patients-can reduce the risk of readmission in patients at high risk of readmission or death when being discharged from hospital. DESIGN, SETTING, AND PATIENTS: High-risk adult hospital discharge patients in Toronto were randomly assigned to either the virtual ward or usual care. A total of 1923 patients were randomized during the course of the study: 960 to the usual care group and 963 to the virtual ward group. The first patient was enrolled on June 29, 2010, and follow-up was completed on June 2, 2014. INTERVENTIONS: Patients assigned to the virtual ward received care coordination plus direct care provision (via a combination of telephone, home visits, or clinic visits) from an interprofessional team for several weeks after hospital discharge. The interprofessional team met daily at a central site to design and implement individualized management plans. Patients assigned to usual care typically received a typed, structured discharge summary, prescription for new medications if indicated, counseling from the resident physician, arrangements for home care as needed, and recommendations, appointments, or both for follow-up care with physicians as indicated. MAIN OUTCOMES AND MEASURES: The primary outcome was a composite of hospital readmission or death within 30 days of discharge. Secondary outcomes included nursing home admission and emergency department visits, each of the components of the primary outcome at 30 days, as well as each of the outcomes (including the composite primary outcome) at 90 days, 6 months, and 1 year. RESULTS: There were no statistically significant between-group differences in the primary or secondary outcomes at 30 or 90 days, 6 months, or 1 year. The primary outcome occurred in 203 of 959 (21.2%) of the virtual ward patients and 235 of 956 (24.6%) of the usual care patients (absolute difference, 3.4%; 95% CI, -0.3% to 7.2%; P = .09). There were no statistically significant interactions to indicate that the virtual ward model of care was more or less effective in any of the prespecified subgroups. CONCLUSIONS AND RELEVANCE: In a diverse group of high-risk patients being discharged from the hospital, we found no statistically significant effect of a virtual ward model of care on readmissions or death at either 30 days or 90 days, 6 months, or 1 year after hospital discharge. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01108172.

Velocity anti-correlation of diametrically opposed galaxy satellites in the low-redshift Universe.

Recent work has shown that the Milky Way and the Andromeda galaxies both possess the unexpected property that their dwarf satellite galaxies are aligned in thin and kinematically coherent planar structures. It is interesting to evaluate the incidence of such planar structures in the larger galactic population, because the Local Group may not be a representative environment. Here we report measurements of the velocities of pairs of diametrically opposed satellite galaxies. In the local Universe (redshift z < 0.05), we find that satellite pairs out to a distance of 150 kiloparsecs from the galactic centre are preferentially anti-correlated in their velocities (99.994 per cent confidence level), and that the distribution of galaxies in the larger-scale environment (out to distances of about 2 megaparsecs) is strongly clumped along the axis joining the inner satellite pair (>7σ confidence). This may indicate that planes of co-rotating satellites, similar to those seen around the Andromeda galaxy, are ubiquitous, and their coherent motion suggests that they represent a substantial repository of angular momentum on scales of about 100 kiloparsecs.

The impact of a worksite weight management program on obesity: a retrospective analysis.

The objective of this study was to examine the efficacy of a worksite weight management program on the reduction of weight and lipid levels in employees and their dependents. This retrospective study examined the impact of a one-on-one worksite weight management program. Patients with a body mass index (BMI)>30, or a BMI>25 and 2 or more risk factors were eligible for inclusion. Laboratory and biometric readings at study end were compared to those at baseline. In addition, the percentage change of patients reaching recommended guideline levels was reported. Of the 310 employees enrolled, 157 completed the program (50.6%) with an average weight loss of 5.6%. Improvement was realized for pre-post weight (-6.0 lbs.; P≤.0001), BMI (-0.9; P≤.0001), blood pressure (systolic: -2.6; P≤.0001; diastolic: -1.9; P≤.0001), total cholesterol (-5.9; P=.0485), low-density lipoprotein cholesterol (LDL; -4.7; P=.0004), and triglycerides (-7.6; P=.0060). The proportion moving to within guideline levels increased for the following metrics: normal BMI category (2.6%; P=.0060),<30 BMI (10%; P≤.0001), systolic and diastolic blood pressure readings (7.7%; P=.0011 and 6.1; P=.0056, respectively), total cholesterol (6.5%; P=.0020), LDL (3.9%; P=.0396), and triglycerides (4.8; P=.0137). Retention in the worksite program was almost twice that seen in some commercial weight loss programs and significant improvements in laboratory and biometric readings were achieved. This study suggests that employer worksite-based programs may have an important role in improving the health of an employee population, which is of particular interest given the high prevalence of obesity and its attendant costs.

The effect of a collaborative pharmacist-hospital care transition program on the likelihood of 30-day readmission.

PURPOSE: The effect of a collaborative pharmacist-hospital care transition program on the likelihood of 30-day readmission was evaluated. METHODS: This retrospective cohort study was conducted in two acute care hospitals within the same hospital system in the southeastern United States. One hospital initiated a care transition program in January 2011; the other hospital did not have such a program. All patients who were discharged from either hospital to home from January 1, 2010, through December 31, 2011, were included in the study. The two key program components included bedside delivery of postdischarge medications and follow-up telephone calls two to three days after discharge. The likelihood of readmission was assessed using multiple logistic regression. RESULTS: Over the 2-year study period, 19,659 unique patients had 26,781 qualifying index admissions, 2,523 of which resulted in a readmission within 30 days of discharge. After adjusting for various demographic and clinical characteristics, the usual care group (i.e., patients who did not participate in the program) had nearly twice the odds of readmission within 30 days (odds ratio [OR], 1.90; 95% confidence interval [CI], 1.35-2.67), compared with the intervention group (i.e., program participants). For patients age 65 years or older, those in the usual care group had a sixfold increase in the odds of a 30-day readmission (OR, 6.05; 95% CI, 1.92-19.00) relative to those in the intervention group. CONCLUSION: A care transition program was associated with a lower likelihood of readmission and had a greater effect on older patients.

Reflections from the NHS in England.

This paper describes the approach taken to "high-risk patients" in England. It provides an overview of the use of risk stratification to identify those at high risk and policy innovations designed to provide preventive care, including the community matron and virtual ward initiatives. We review how such initiatives have been evaluated and discuss the findings of those evaluations. We conclude with a discussion of next steps for the use of risk stratification, such as honing the focus to identify those individuals most likely to respond to preventive care, and we sound a cautionary note in favour of realistic expectations regarding the use of risk stratification and the emergence of anticipated benefits.

Integrating care for high-risk patients in England using the virtual ward model: lessons in the process of care integration from three case sites.

BACKGROUND: Patients at high risk of emergency hospitalisation are particularly likely to experience fragmentation in care. The virtual ward model attempts to integrate health and social care by offering multidisciplinary case management to people at high predicted risk of unplanned hospitalisation. OBJECTIVE: To describe the care practice in three virtual ward sites in England and to explore how well each site had achieved meaningful integration. METHOD: Case studies conducted in Croydon, Devon and Wandsworth during 2011-2012, consisting of semi-structured interviews, workshops, and site visits. RESULTS: Different versions of the virtual wards intervention had been implemented in each site. In Croydon, multidisciplinary care had reverted back to one-to-one case management. CONCLUSIONS: To integrate successfully, virtual ward projects should safeguard the multidisciplinary nature of the intervention, ensure the active involvement of General Practitioners, and establish feedback processes to monitor performance such as the number of professions represented at each team meeting.

How health systems could avert 'triple fail' events that are harmful, are costly, and result in poor patient satisfaction.

Health care systems in many countries are using the "Triple Aim"--to improve patients' experience of care, to advance population health, and to lower per capita costs--as a focus for improving quality. Population strategies for addressing the Triple Aim are becoming increasingly prevalent in developed countries, but ultimately success will also require targeting specific subgroups and individuals. Certain events, which we call "Triple Fail" events, constitute a simultaneous failure to meet all three Triple Aim goals. The risk of experiencing different Triple Fail events varies widely across people. We argue that by stratifying populations according to each person's risk and anticipated response to an intervention, health systems could more effectively target different preventive interventions at particular risk strata. In this article we describe how such an approach could be planned and operationalized. Policy makers should consider using this stratified approach to reduce the incidence of Triple Fail events, thereby improving outcomes, enhancing patient experience, and lowering costs.

A vast, thin plane of corotating dwarf galaxies orbiting the Andromeda galaxy.

Dwarf satellite galaxies are thought to be the remnants of the population of primordial structures that coalesced to form giant galaxies like the Milky Way. It has previously been suspected that dwarf galaxies may not be isotropically distributed around our Galaxy, because several are correlated with streams of H I emission, and may form coplanar groups. These suspicions are supported by recent analyses. It has been claimed that the apparently planar distribution of satellites is not predicted within standard cosmology, and cannot simply represent a memory of past coherent accretion. However, other studies dispute this conclusion. Here we report the existence of a planar subgroup of satellites in the Andromeda galaxy (M 31), comprising about half of the population. The structure is at least 400 kiloparsecs in diameter, but also extremely thin, with a perpendicular scatter of less than 14.1 kiloparsecs. Radial velocity measurements reveal that the satellites in this structure have the same sense of rotation about their host. This shows conclusively that substantial numbers of dwarf satellite galaxies share the same dynamical orbital properties and direction of angular momentum. Intriguingly, the plane we identify is approximately aligned with the pole of the Milky Way's disk and with the vector between the Milky Way and Andromeda.

Development of a predictive model to identify inpatients at risk of re-admission within 30 days of discharge (PARR-30).

OBJECTIVES: To develop an algorithm for identifying inpatients at high risk of re-admission to a National Health Service (NHS) hospital in England within 30 days of discharge using information that can either be obtained from hospital information systems or from the patient and their notes. DESIGN: Multivariate statistical analysis of routinely collected hospital episode statistics (HES) data using logistic regression to build the predictive model. The model's performance was calculated using bootstrapping. SETTING: HES data covering all NHS hospital admissions in England. PARTICIPANTS: The NHS patients were admitted to hospital between April 2008 and March 2009 (10% sample of all admissions, n=576 868). MAIN OUTCOME MEASURES: Area under the receiver operating characteristic curve for the algorithm, together with its positive predictive value and sensitivity for a range of risk score thresholds. RESULTS: The algorithm produces a 'risk score' ranging (0-1) for each admitted patient, and the percentage of patients with a re-admission within 30 days and the mean re-admission costs of all patients are provided for 20 risk bands. At a risk score threshold of 0.5, the positive predictive value (ie, percentage of inpatients identified as high risk who were subsequently re-admitted within 30 days) was 59.2% (95% CI 58.0% to 60.5%); representing 5.4% (95% CI 5.2% to 5.6%) of all inpatients who would be re-admitted within 30 days (sensitivity). The area under the receiver operating characteristic curve was 0.70 (95% CI 0.69 to 0.70). CONCLUSIONS: We have developed a method of identifying inpatients at high risk of unplanned re-admission to NHS hospitals within 30 days of discharge. Though the models had a low sensitivity, we show how to identify subgroups of patients that contain a high proportion of patients who will be re-admitted within 30 days. Additional work is necessary to validate the model in practice.

Multidisciplinary case management for patients at high risk of hospitalization: comparison of virtual ward models in the United kingdom, United States, and Canada.

Virtual wards are a model for delivering multidisciplinary case management to people who are at high predicted risk of unplanned acute care hospitalization. First introduced in Croydon, England, in 2006, this concept has since been adopted and adapted by health care organizations in other parts of the United Kingdom and internationally. In this article, the authors review the model of virtual wards as originally described-with its twin pillars of (1) using a predictive model to identify people who are at high risk of future emergency hospitalization, and (2) offering these individuals a period of intensive, multidisciplinary preventive care at home using the systems, staffing, and daily routines of a hospital ward. The authors then describe how virtual wards have been modified and implemented in 6 sites in the United Kingdom, United States, and Canada where they are subject to formal evaluation. Like hospital wards, virtual wards vary in terms of patient selection, ward configuration, staff composition, and ward processes. Policy makers and researchers should be aware of these differences when considering the evaluation results of studies investigating the cost-effectiveness of virtual wards.

Overlap of hospital use and social care in older people in England.

OBJECTIVES: To link pseudonymous health and social care use data in order to determine what proportion of older people access hospital and social care services. METHODS: Retrospective analysis of linked, pseudonymous, routine service use data of people aged 75 and over (n = 133,055) drawn from the operational systems of four primary care trusts and their corresponding local authorities in England. RESULTS: Fourteen percent of older people received local authority-funded social care in one year, 59% accessed NHS hospital care and 10% accessed both types of service. Most people using social care also used a hospital service (71%). This was a higher proportion than for people who did not use social care services (57%, P < 0.001). However, the use of hospitals varied by type of social care such that the residents of care homes had fewer admissions to hospital, fewer Accident and Emergency attendances and fewer outpatient visits than people receiving high intensity home care. CONCLUSIONS: Using routine data from large populations, we have demonstrated interactions in the use of hospital care and social care for older people. Residents of care homes tend to use hospitals less frequently than people receiving home care. More detailed work is required to explain this phenomenon.