ATLASGAL - star forming efficiencies and the Galactic star formation rate

The ATLASGAL survey has characterized the properties of approximately 1000 embedded H ii regions and found an empirical relationship between the clump mass and bolometric luminosity that covers 3-4 orders of magnitude. Comparing this relation with simulated clusters drawn from an initial mass function and using different star formation efficiencies we find that a single value is unable to fit the observed luminosity to mass (L/M) relation. We have used a Monte Carlo simulation to generate 200 000 clusters using the L/M-ratio as a constraint to investigate how the star formation efficiency changes as a function of clump mass. This has revealed that the star formation efficiency decreases with increasing clump mass with a value of 0.2 for clumps with masses of a few hundred solar masses and dropping to 0.08 for clumps with masses of a few thousand solar masses. We find good agreement between our results and star formation efficiencies determined from counts of embedded objects in nearby molecular clouds. Using the star formation efficiency relationship and the infrared excess time for embedded star formation of 2 ± 1 Myr we estimate the Galactic star formation rate to be approximately 0.9 ± 0.45 M· yr-1, which is in good agreement with previously reported values. This model has the advantage of providing a direct means of determining the star formation rate and avoids the difficulties encountered in converting infrared luminosities to stellar mass that affect previous galactic and extragalactic studies

ATLASGAL - evolutionary trends in high-mass star formation

ATLASGAL is an 870-μm dust survey of 420 deg2 the inner Galactic plane and has been used to identify ∼10 000 dense molecular clumps. Dedicated follow-up observations and complementary surveys are used to characterize the physical properties of these clumps, map their Galactic distribution, and investigate the evolutionary sequence for high-mass star formation. The analysis of the ATLASGAL data is ongoing: We present an up-to-date version of the catalogue. We have classified 5007 clumps into four evolutionary stages (quiescent, protostellar, young stellar objects and H ii regions) and find similar numbers of clumps in each stage, suggesting a similar lifetime. The luminosity-to-mass (Lbol/Mfwhm) ratio curve shows a smooth distribution with no significant kinks or discontinuities when compared to the mean values for evolutionary stages indicating that the star formation process is continuous and that the observational stages do not represent fundamentally different stages or changes in the physical mechanisms involved. We compare the evolutionary sample with other star formation tracers (methanol and water masers, extended green objects and molecular outflows) and find that the association rates with these increases as a function of evolutionary stage, confirming that our classification is reliable. This also reveals a high association rate between quiescent sources and molecular outflows, revealing that outflows are the earliest indication that star formation has begun and that star formation is already ongoing in many of the clumps that are dark even at 70 μm

Rapid Diagnosis of Tuberculosis with the Xpert MTB/RIF Assay in High Burden Countries: A Cost-Effectiveness Analysis

A cost-effectiveness study by Frank Cobelens and colleagues reveals that Xpert MTB/RIF is a cost-effective method of tuberculosis diagnosis that is suitable for use in low- and middle-income settings

Where should patients with or at risk of delirium be treated in an acute care system? Comparing the rates of delirium in patients receiving usual care versus alternative care : a systematic review and meta‐analysis

Background: Delirium is an acute condition that occurs in hospitalised patients and leads to poor patient outcomes that can last long term. Therefore, the importance of prevention is undeniable and adopting new models of care for at risk patients should be prioritised. Objectives: This systematic review and meta‐analysis will assess the effectiveness of different interventions designed to prevent or manage delirium in acutely unwell hospitalised patients. Methods: MEDLINE, EMBASE, PsychINFO, OpenGrey, Web of Science and reference lists of journals were searched. Eligible studies reported on incidence or duration of delirium, used a validated delirium diagnostic tool, and compared an intervention to either a control or another intervention group. Meta‐analyses were conducted, and GRADE pro software was used to assess the certainty of evidence. This review is registered on PROSPERO. Results: A total of 59 studies were included and 33 were eligible for meta‐analysis. Delirium incidence was most significantly reduced by non‐pharmacological multicomponent interventions compared to usual care, with pooled risk ratios of 0.57 (95% CI: 0.44 to 0.73, ten randomised controlled trials) and 0.47 (95% CI: 0.35 to 0.64, six observational studies). Single component interventions did not significantly reduce delirium incidence compared to usual care in seven randomised trials (risk ratio= 0.92, 95% CI: 0.81 to 1.04). The most effective single component intervention in reducing delirium incidence, was a hospital‐at‐home intervention (risk ratio = 0.29, 95% CI: 0.09 to 0.87). Conclusions: Non‐pharmacological multicomponent interventions are effective in preventing delirium, however the same cannot be said for other interventions due to uncertain results. There is some evidence that providing multicomponent interventions in patients’ homes is more effective than a hospital setting. Therefore, researching the benefits of hospital‐at‐home interventions in delirium prevention is recommended