We present the Census of the Local Universe (CLU) narrowband survey to search for emission-line (H ) galaxies. CLU-H has imaged 3π of the sky (26,470 deg2) with four narrowband filters that probe a ...distance out to 200 Mpc. We have obtained spectroscopic follow-up for galaxy candidates in 14 preliminary fields (101.6 deg2) to characterize the limits and completeness of the survey. In these preliminary fields, CLU can identify emission lines down to an H flux limit of 10−14 erg s−1 cm−2 at 90% completeness, and recovers 83% (67%) of the H flux from cataloged galaxies in our search volume at the = 2.5 ( = 5) color excess levels. The contamination from galaxies with no emission lines is 61% (12%) for = 2.5 ( = 5). Also, in the regions of overlap between our preliminary fields and previous emission-line surveys, we recover the majority of the galaxies found in previous surveys and identify an additional 300 galaxies. In total, we find 90 galaxies with no previous distance information, several of which are interesting objects: 7 blue compact dwarfs, 1 green pea, and a Seyfert galaxy; we also identify a known planetary nebula. These objects show that the CLU-H survey can be a discovery machine for objects in our own Galaxy and extreme galaxies out to intermediate redshifts. However, the majority of the CLU-H galaxies identified in this work show properties consistent with normal star-forming galaxies. CLU-H galaxies with new redshifts will be added to existing galaxy catalogs to focus the search for the electromagnetic counterpart to gravitational wave events.
OBJECTIVE:To perform a systematic review and meta-analysis of the literature on teaching airway management using technology-enhanced simulation.
DATA SOURCES:We searched MEDLINE, EMBASE, CINAHL, ...PsycINFO, ERIC, Web of Science, and Scopus for eligible articles through May 11, 2011.
STUDY SELECTION:Observational or controlled trials instructing medical professionals in direct or fiberoptic intubation, surgical airway, and/or supraglottic airway using technology-enhanced simulation were included. Two reviewers determined eligibility.
DATA EXTRACTION:Study quality, instructional design, and outcome data were abstracted independently and in duplicate.
DATA SYNTHESIS:Of 10,904 articles screened, 76 studies were included (n = 5,226 participants). We used random effects meta-analysis to pool results. In comparison with no intervention, simulation training was associated with improved outcomes for knowledge (standardized mean difference, 0.77 95% CI, 0.19–1.35; n = 7 studies) and skill (1.01 0.68–1.34; n = 28) but not for behavior (0.52 –0.30 to 1.34; n = 4) or patient outcomes (–0.12 –0.41 to 0.16; n = 4). In comparison with nonsimulation interventions, simulation training was associated with increased learner satisfaction (0.54 0.37–0.71; n = 2), improved skills (0.64 0.12–1.16; n = 5), and patient outcomes (0.86 0.12–1.59; n = 3) but not knowledge (0.29 –0.28 to 0.86; n = 4). We found few comparative effectiveness studies exploring how to optimize the use of simulation-based training, and these revealed inconsistent results. For example, animal models were found superior to manikins in one study (p = 0.004) using outcome of task speed but inferior in another study in terms of skill ratings (p = 0.02). Five studies comparing simulators of high versus low technical sophistication found no significant difference in skill outcomes (p > 0.31). Limitations of this review include heterogeneity (I > 50% for most analysis) and variation in quality among primary studies.
CONCLUSIONS:Simulation-based airway management curriculum is superior to no intervention and nonsimulation intervention for important education outcomes. Further research is required to fine-tune optimal curricular design.
Abstract
Nearly all current simulations predict that outcomes of the star formation process, such as the fraction of stars that form in bound clusters (Γ), depend on the intensity of star formation ...activity (Σ
SFR
) in the host galaxy. The exact shape and strength of the predicted correlations, however, vary from simulation to simulation. Observational results also remain unclear at this time, because most works have mixed estimates made from very young clusters for galaxies with higher Σ
SFR
with those from older clusters for galaxies with lower Σ
SFR
. The three blue compact dwarf (BCD) galaxies ESO 185-IG13, ESO 338-IG04, and Haro 11 have played a central role on the observational side because they have some of the highest known Σ
SFR
and published values of Γ. We present new estimates of Γ for these BCDs in three age intervals (1–10 Myr, 10–100 Myr, 100–400 Myr), based on age-dating, which includes H
α
photometry to better discriminate between clusters younger and older than ≈10 Myr. We find significantly lower values for Γ(1–10 Myr) than published previously. The likely reason for the discrepancy is that previous estimates appear to be based on age–reddening results that underestimated ages and overestimated reddening for many clusters, artificially boosting Γ(1–10 Myr). We also find that fewer stars remain in clusters over time, with ≈15%–39% in 1–10 Myr clusters, ≈5%–7% in 10–100 Myr clusters, and ≈1%–2% in 100–400 Myr clusters. We find no evidence that Γ increases with Σ
SFR
. These results imply that cluster formation efficiency does not vary with star formation intensity in the host galaxy. If confirmed, our results will help guide future assumptions in galaxy-scale simulations of cluster formation and evolution.
Abstract
The ultraluminous infrared galaxy Arp 220 is a late-stage merger with several tidal structures in the outskirts and two very compact, dusty nuclei that show evidence for extreme star ...formation and host at least one active galactic nucleus (AGN). New and archival high-resolution images taken by the Hubble Space Telescope provide a state-of-the-art view of the structures, dust, and stellar clusters in Arp 220. These images cover the near-ultraviolet, optical, and near-infrared in both broad- and narrowband filters. We find that ∼90% of the H
α
emission arises from a shock-ionized bubble emanating from the AGN in the western nucleus, while the nuclear disks dominate the Pa
β
emission. Four very young (∼3–6 Myr) but lower-mass (≲10
4
M
⊙
) clusters are detected in H
α
within a few arcseconds of the nuclei, but they produce less than 1% of the line emission. We see little evidence for a population of massive clusters younger than 100 Myr anywhere in Arp 220, unlike previous reports in the literature. From the masses and ages of the detected clusters, we find that star formation took place more or less continuously starting approximately a few gigayears ago with a moderate rate between ≈3 and 12
M
⊙
yr
−1
. Approximately 100 Myr ago, star formation shut off suddenly everywhere (possibly due to a merging event), except in the nuclear disks. A very recent flicker of weak star formation produced the four young, low-mass clusters, while the rest of the galaxy appears to have remained in a post-starburst state. Cluster ages indicate that the tidal structures on the west side of the galaxy are older than those on the east side, but all appear to predate the shutoff of star formation. Arp 220 has many of the characteristics expected of a “shocked post-starburst galaxy,” since most of the system has been in a post-starburst state for the past ∼100 Myr and the detected H
α
emission arises from shocked rather than photoionized gas.
Abstract We present a new study of the cluster populations in the blue compact dwarf galaxies (BCD) ESO185-IG13, ESO338-IG04, and Haro11, based on new and archival high-resolution images taken by the ...Hubble Space Telescope, and the first to probe the populations older than ≈100 Myr. BCDs are believed to experience intense bursts of star formation (including at the present day) after long periods of quiescence, but little is known about the timing, frequency, duration, and strength of these bursts or about their star formation histories in general. We find that the cluster population in each of the three galaxies studied here has its own unique distribution of colors and hence a unique cluster and star formation history. From an assumed correlation between the normalization of the cluster mass function and the star formation rate of the host galaxy, we construct cluster-based star formation histories over the past ≈few × Gyr and find that only Haro11 is currently experiencing a burst (≈factor of 10 increase in the rate of star formation for the last ≈20 Myr), whereas ESO185 experienced enhanced star formation (by a factor ≈4) between 10 and 40 Myr ago, and ESO338 has had a fairly constant SFH over the past few Gyr. These findings indicate that not all BCDs are experiencing a burst of star formation at the present day, and that some have been forming stars and clusters at a fairly steady rate (within a factor of ≈2–3) over the past few Gyr. This scenario is similar to the histories of dwarf irregular and dwarf starburst galaxies, which have star formation rates that are 10–1000 times lower than those in BCDs.
Abstract
We investigate how star formation is spatially organized in the grand-design spiral NGC 1566 from deep Hubble Space Telescope photometry with the Legacy ExtraGalactic UV Survey. Our ...contour-based clustering analysis reveals 890 distinct stellar conglomerations at various levels of significance. These star-forming complexes are organized in a hierarchical fashion with the larger congregations consisting of smaller structures, which themselves fragment into even smaller and more compact stellar groupings. Their size distribution, covering a wide range in length-scales, shows a power law as expected from scale-free processes. We explain this shape with a simple ‘fragmentation and enrichment’ model. The hierarchical morphology of the complexes is confirmed by their mass–size relation that can be represented by a power law with a fractional exponent, analogous to that determined for fractal molecular clouds. The surface stellar density distribution of the complexes shows a lognormal shape similar to that for supersonic non-gravitating turbulent gas. Between 50 and 65 per cent of the recently formed stars, as well as about 90 per cent of the young star clusters, are found inside the stellar complexes, located along the spiral arms. We find an age difference between young stars inside the complexes and those in their direct vicinity in the arms of at least 10 Myr. This time-scale may relate to the minimum time for stellar evaporation, although we cannot exclude the in situ formation of stars. As expected, star formation preferentially occurs in spiral arms. Our findings reveal turbulent-driven hierarchical star formation along the arms of a grand-design galaxy.
Postoperative delirium (POD) is common in the elderly and associated with adverse outcomes. The cognitive and functional sequelae of POD in elective surgical patients are not known. We sought to ...determine whether (1) lower scores on sensitive neurocognitive tests are an independent risk factor for POD in elderly surgical patients, and (2) POD predicts cognitive and functional decline 3 months postoperatively.
We conducted a prospective, cohort study on patients ≥65 years old undergoing total hip or knee arthroplasty. Participants underwent preoperative neurocognitive and functional testing. POD was diagnosed using the Confusion Assessment Method. Patients who developed POD and matched controls underwent repeat neurocognitive and functional testing 3 months after surgery.
Four hundred eighteen patients met entry criteria, and 42 (10%) developed POD. There were no differences in baseline Mini-Mental State Examination scores, alcohol abuse, depression, and verbal intelligence between groups. Independent predictors of POD included age, history of psychiatric illness, decreased functional status, and decreased verbal memory. For all tests, changes from before to 3 months after surgery were similar between those patients with POD and matched controls.
Subtly reduced preoperative neurocognitive and functional status predict POD. However, in the small group that developed POD, there was no evidence of cognitive and functional decline 3 months after surgery. POD is associated with decreased preoperative cognitive reserve but, in elderly elective surgical patients, may be without adverse cognitive or functional sequelae 3 months postoperatively.
We present the first study of GALEX far-ultraviolet (FUV) luminosity functions of individual star-forming regions within a sample of 258 nearby galaxies spanning a large range in total stellar mass ...and star formation properties. We identify ∼65 000 star-forming regions (i.e. FUV sources), measure each galaxy's luminosity function, and characterize the relationships between the luminosity function slope (α) and several global galaxy properties. A final sample of 82 galaxies with reliable luminosity functions are used to define these relationships and represent the largest sample of galaxies with the largest range of galaxy properties used to study the connection between luminosity function properties and galaxy environment. We find that α correlates with global star formation properties, where galaxies with higher star formation rates and star formation rate densities (ΣSFR) tend to have flatter luminosity function slopes. In addition, we find that neither stochastic sampling of the luminosity function in galaxies with low-number statistics nor the effects of blending due to distance can fully account for these trends. We hypothesize that the flatter slopes in high ΣSFR galaxies is due to higher gas densities and higher star formation efficiencies which result in proportionally greater numbers of bright star-forming regions. Finally, we create a composite luminosity function composed of star-forming regions from many galaxies and find a break in the luminosity function at brighter luminosities. However, we find that this break is an artefact of varying detection limits for galaxies at different distances.
The first two months of the third Advanced LIGO and Virgo observing run (2019 April-May) showed that distant gravitational-wave (GW) events can now be readily detected. Three candidate mergers ...containing neutron stars (NS) were reported in a span of 15 days, all likely located more than 100 Mpc away. However, distant events such as the three new NS mergers are likely to be coarsely localized, which highlights the importance of facilities and scheduling systems that enable deep observations over hundreds to thousands of square degrees to detect the electromagnetic counterparts. On 2019 May 10 02:59:39.292 UT the GW candidate S190510g was discovered and initially classified as a binary neutron star (BNS) merger with 98% probability. The GW event was localized within an area of 3462 deg2, later refined to 1166 deg2 (90%) at a distance of 227 92 Mpc. We triggered Target-of-Opportunity observations with the Dark Energy Camera (DECam), a wide-field optical imager mounted at the prime focus of the 4 m Blanco Telescope at Cerro Tololo Inter-American Observatory in Chile. This Letter describes our DECam observations and our real-time analysis results, focusing in particular on the design and implementation of the observing strategy. Within 24 hr of the merger time, we observed 65% of the total enclosed probability of the final skymap with an observing efficiency of 94%. We identified and publicly announced 13 candidate counterparts. S190510g was reclassified 1.7 days after the merger, after our observations were completed, with a "BNS merger" probability reduced from 98% to 42% in favor of a "terrestrial classification.
We present a detailed clustering analysis of the young stellar population across the star-forming ring galaxy NGC 6503, based on the deep Hubble Space Telescope photometry obtained with the Legacy ...ExtraGalactic UV Survey. We apply a contour-based map analysis technique and identify in the stellar surface density map 244 distinct star-forming structures at various levels of significance. These stellar complexes are found to be organized in a hierarchical fashion with 95 per cent being members of three dominant super-structures located along the star-forming ring. The size distribution of the identified structures and the correlation between their radii and numbers of stellar members show power-law behaviours, as expected from scale-free processes. The self-similar distribution of young stars is further quantified from their autocorrelation function, with a fractal dimension of ∼1.7 for length-scales between ∼20 pc and 2.5 kpc. The young stellar radial distribution sets the extent of the star-forming ring at radial distances between 1 and 2.5 kpc. About 60 per cent of the young stars belong to the detected stellar structures, while the remaining stars are distributed among the complexes, still inside the ring of the galaxy. The analysis of the time-dependent clustering of young populations shows a significant change from a more clustered to a more distributed behaviour in a time-scale of ∼60 Myr. The observed hierarchy in stellar clustering is consistent with star formation being regulated by turbulence across the ring. The rotational velocity difference between the edges of the ring suggests shear as the driving mechanism for this process. Our findings reveal the interesting case of an inner ring forming stars in a hierarchical fashion.
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