331 research outputs found
Luminous and Dark Matter in the Milky Way
(Abridged) Axisymmetric models of the Milky Way exhibit strong interrelations
between the Galactic constants (R_0 and T_0), the stellar columndensity (S_*)
and the shape of the dark matter (DM) halo. Here we present analytical
relations that can be used to investigate the effects of the uncertain gaseous
velocity dispersion on the HI flaring constraints. The contribution of cosmic
rays and magnetic fields to the pressure gradients is small. A significantly
flattened dark matter halo is only possible if R_0 <~ 6.8 kpc.
If R_0 is larger than ~7 kpc, or T_0 >~ 170 km/s, we can rule out two DM
candidates that require a highly flattened DM halo: 1) decaying massive
neutrinos; and 2) a disk of cold molecular hydrogen.
It is only possible to construct self-consistent models of the Galaxy based
on the IAU-recommended values for the Galactic constants in the unlikely case
that the the stellar columndensity is smaller than ~18 M_sun/pc^2. If we assume
that the halo is oblate and S_* = 35 +/- 5 M_sun/pc^2, R_0 <~ 8 kpc and T_0 <~
200 km/s.
Combining the best kinematical and star-count estimates of S_*, we conclude
that: 25 <~ S_* <~ 45 M_sun/pc^2. Kuijken & Gilmore's (1991) determination of
the columndensity of matter with |z|<=1.1 kpc is robust and valid over a wide
range of Galactic constants.
Our mass models show that the DM density in the Galactic centre is uncertain
by a factor 1000. In the Solar neighbourhood we find: rho_DM ~0.42 GeV/c^2/cm^3
or (11 +/- 5) mM_sun/pc^3 -- roughly 15% of rho_tot.Comment: Accepted for publication in MNRA
The DiskMass Survey. I. Overview
We present a survey of the mass surface-density of spiral disks, motivated by
outstanding uncertainties in rotation-curve decompositions. Our method exploits
integral-field spectroscopy to measure stellar and gas kinematics in nearly
face-on galaxies sampled at 515, 660, and 860 nm, using the custom-built
SparsePak and PPak instruments. A two-tiered sample, selected from the UGC,
includes 146 nearly face-on galaxies, with B<14.7 and disk scale-lengths
between 10 and 20 arcsec, for which we have obtained H-alpha velocity-fields;
and a representative 46-galaxy subset for which we have obtained stellar
velocities and velocity dispersions. Based on re-calibration of extant
photometric and spectroscopic data, we show these galaxies span factors of 100
in L(K) (0.03 < L/L(K)* < 3), 8 in L(B)/L(K), 10 in R-band disk central
surface-brightness, with distances between 15 and 200 Mpc. The survey is
augmented by 4-70 micron Spitzer IRAC and MIPS photometry, ground-based
UBVRIJHK photometry, and HI aperture-synthesis imaging. We outline the
spectroscopic analysis protocol for deriving precise and accurate line-of-sight
stellar velocity dispersions. Our key measurement is the dynamical disk-mass
surface-density. Star-formation rates and kinematic and photometric regularity
of galaxy disks are also central products of the study. The survey is designed
to yield random and systematic errors small enough (i) to confirm or disprove
the maximum-disk hypothesis for intermediate-type disk galaxies, (ii) to
provide an absolute calibration of the stellar mass-to-light ratio well below
uncertainties in present-day stellar-population synthesis models, and (iii) to
make significant progress in defining the shape of dark halos in the inner
regions of disk galaxies.Comment: To appear in ApJ; 72 pages, 3 tables, 18 figures. High-resolution
version available at
http://www.astro.wisc.edu/~mab/publications/DMS_I_preprint.pd
Novel proposals for FAIR, automated, recommendable, and robust workflows
Funding: This work is partly funded by NSF award OAC-1839900. This material is based upon work supported by the U.S. Department of Energy, Office of Science, under contract number DE-AC02-06CH11357. libEnsemble was developed as part of the Exascale Computing Project (17-SC-20-SC), a collaborative effort of the U.S. Department of Energy Office of Science and the National Nuclear Security Administration. This research used resources of the OLCF at ORNL, which is supported by the Office of Science of the U.S. DOE under Contract No. DE-AC05-00OR22725.Lightning talks of the Workflows in Support of Large-Scale Science (WORKS) workshop are a venue where the workflow community (researchers, developers, and users) can discuss work in progress, emerging technologies and frameworks, and training and education materials. This paper summarizes the WORKS 2022 lightning talks, which cover five broad topics: data integrity of scientific workflows; a machine learning-based recommendation system; a Python toolkit for running dynamic ensembles of simulations; a cross-platform, high-performance computing utility for processing shell commands; and a meta(data) framework for reproducing hybrid workflows.Postprin
Detecting referral and selection bias by the anonymous linkage of practice, hospital and clinic data using Secure and Private Record Linkage (SAPREL): case study from the evaluation of the Improved Access to Psychological Therapy (IAPT) service
Background: The evaluation of demonstration sites set up to provide improved access to psychological therapies (IAPT) comprised the study of all people identified as having common mental health problems (CMHP), those referred to the IAPT service, and a sample of attenders studied in-depth. Information technology makes it feasible to link practice, hospital and IAPT clinic data to evaluate the representativeness of these samples. However, researchers do not have permission to browse and link these data without the patientsâ consent. Objective: To demonstrate the use of a mixed deterministic-probabilistic method of secure and private record linkage (SAPREL) - to describe selection bias in subjects chosen for in-depth evaluation. Method: We extracted, pseudonymised and used fuzzy logic to link multiple health records without the researcher knowing the patientâs identity. The method can be characterised as a three party protocol mainly using deterministic algorithms with dynamic linking strategies; though incorporating some elements of probabilistic linkage. Within the data providersâ safe haven we extracted: Demographic data, hospital utilisation and IAPT clinic data; converted post code to index of multiple deprivation (IMD); and identified people with CMHP. We contrasted the age, gender, ethnicity and IMD for the in-depth evaluation sample with people referred to IAPT, use hospital services, and the population as a whole. Results: The in IAPT-in-depth group had a mean age of 43.1 years; CI: 41.0 - 45.2 (n = 166); the IAPT-referred 40.2 years; CI: 39.4 - 40.9 (n = 1118); and those with CMHP 43.6 years SEM 0.15. (n = 12210). Whilst around 67% of those with a CMHP were women, compared to 70% of those referred to IAPT, and 75% of those subject to indepth evaluation (Chi square p< 0.001). The mean IMD score for the in-depth evaluation group was 36.6; CI: 34.2 - 38.9; (n = 166); of those referred to IAPT 38.7; CI: 37.9 - 39.6; (n = 1117); and of people with CMHP 37.6; CI 37.3- 37.9; (n = 12143). Conclusions: The sample studied in-depth were older, more likely female, and less deprived than people with CMHP, and fewer had recorded ethnic minority status. Anonymous linkage using SAPREL provides insight into the representativeness of a study population and possible adjustment for selection bias
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Multiscale scenarios for nature futures
Targets for human development are increasingly connected with targets for nature, however, existing scenarios do not explicitly address this relationship. Here, we outline a strategy to generate scenarios centred on our relationship with nature to inform decision-making at multiple scales
Genetic diversity Goals and Targets have improved, but remain insufficient for clear implementation of the post-2020 global biodiversity framework
Genetic diversity among and within populations of all species is necessary for people and nature to survive and thrive in a changing world. Over the past three years, commitments for conserving genetic diversity have become more ambitious and specific under the Convention on Biological Diversityâs (CBD) draft post-2020 global biodiversity framework (GBF). This Perspective article comments on how goals and targets of the GBF have evolved, the improvements that are still needed, lessons learned from this process, and connections between goals and targets and the actions and reporting that will be needed to maintain, protect, manage and monitor genetic diversity. It is possible and necessary that the GBF strives to maintain genetic diversity within and among populations of all species, to restore genetic connectivity, and to develop national genetic conservation strategies, and to report on these using proposed, feasible indicators
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
Past, present and future of the ecosystem services provided by cetacean carcasses
Ecosystem services associated with cetacean strandings have been altered by humans through exploitation of wild populations during the whaling era and more recently by regulations on carcass management and disposal to abide by environmental health requirements. Here, we systematically review the scientific literature and gather data on cetacean strandings worldwide to: 1) identify the ecosystem services provided by stranded cetacean carcasses in the past and present; 2) estimate the density of cetacean strandings currently occurring in selected coastal areas around the globe, and analyse its association with human population density and regulations; and 3) identify and discuss the regulations and methods concerned with whale carcass disposal in specific regions of the world. Our literature review revealed that stranded cetacean carcasses have provided a rich and varied array of provisioning, regulating, cultural, and supporting ecosystem services to ancient and modern civilisations worldwide. Also, we found that the current density of stranded carcasses (mean: 0.090 strandings âą yearâ1 âą kmâ1; range: 0.001â0.978) and the disposal methods widely varied across the studied regions and countries. In addition, neither human population density nor the existence of regulations were good predictors of stranding densities. Finally, we provide recommendations for the future management of stranded cetacean carcasses, by identifying those disposal methods that minimize costs and maximize ecosystem functions and services. In particular, we encourage natural decomposition in situ whenever possible; otherwise, the present coastal management strategies could be improved by including zoning, seasonal use limitation and educational outreach depending upon the local scenario. Overall, further socio-ecological research is strongly needed to guide stranded cetacean carcass management towards enhancing the net benefits that humans and ecosystems gain from carcasses, especially considering that coastal areas become more populated, new disposal regulations are approved, and cetacean populations are recovering â and thus strandings may become more frequent
Computerized clinical decision support systems for acute care management: A decision-maker-researcher partnership systematic review of effects on process of care and patient outcomes
<p>Abstract</p> <p>Background</p> <p>Acute medical care often demands timely, accurate decisions in complex situations. Computerized clinical decision support systems (CCDSSs) have many features that could help. However, as for any medical intervention, claims that CCDSSs improve care processes and patient outcomes need to be rigorously assessed. The objective of this review was to systematically review the effects of CCDSSs on process of care and patient outcomes for acute medical care.</p> <p>Methods</p> <p>We conducted a decision-maker-researcher partnership systematic review. MEDLINE, EMBASE, Evidence-Based Medicine Reviews databases (Cochrane Database of Systematic Reviews, DARE, ACP Journal Club, and others), and the Inspec bibliographic database were searched to January 2010, in all languages, for randomized controlled trials (RCTs) of CCDSSs in all clinical areas. We included RCTs that evaluated the effect on process of care or patient outcomes of a CCDSS used for acute medical care compared with care provided without a CCDSS. A study was considered to have a positive effect (<it>i.e.</it>, CCDSS showed improvement) if at least 50% of the relevant study outcomes were statistically significantly positive.</p> <p>Results</p> <p>Thirty-six studies met our inclusion criteria for acute medical care. The CCDSS improved process of care in 63% (22/35) of studies, including 64% (9/14) of medication dosing assistants, 82% (9/11) of management assistants using alerts/reminders, 38% (3/8) of management assistants using guidelines/algorithms, and 67% (2/3) of diagnostic assistants. Twenty studies evaluated patient outcomes, of which three (15%) reported improvements, all of which were medication dosing assistants.</p> <p>Conclusion</p> <p>The majority of CCDSSs demonstrated improvements in process of care, but patient outcomes were less likely to be evaluated and far less likely to show positive results.</p
Molecular insights into an ancient form of Pagetâs disease of bone
Pagetâs disease of bone (PDB) is a chronic skeletal disorder that can affect one or several bones in individuals over 55 years of age. PDB like changes have been reported in archaeological remains as old as Roman, although accurate diagnosis and natural history of the disease is lacking. Six skeletons from a collection of 130 excavated at Norton Priory in the North West of England, which dates to medieval times, show atypical and extensive pathological changes resembling contemporary PDB affecting up to 75% of individual skeletons. Disease prevalence in the remaining collection is high, at least 16% of adults, with age at death estimations as low as 35 years. Despite these atypical features, paleoproteomic analysis identified sequestosome 1 (SQSTM1) or p62, a protein central to the pathological milieu of PDB, as one of the few non69 collagenous human sequences preserved in skeletal samples. Targeted proteomic analysis detected >60% of the ancient p62 primary sequence with western blotting indicating p62 abnormalities including in dentition. Direct sequencing of ancient DNA excluded contemporary PDB associated SQSTM1 mutations. Our observations indicate that the ancient p62 protein is likely modified within its C-terminal ubiquitin associated (UBA) domain. Ancient microRNAs were remarkably preserved in an osteosarcoma from a skeleton with extensive disease, with miR-16 expression consistent with that reported in contemporary PDB associated bone tumours. Our work displays the use of proteomics to inform diagnosis of ancient disease such as atypical PDB, which has unusual features presumably potentiated by as yet unidentified environmental or genetic factors
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