297 research outputs found
Traffic-Related Air Pollution and All-Cause Mortality during Tuberculosis Treatment in California.
BackgroundAmbient air pollution and tuberculosis (TB) have an impact on public health worldwide, yet associations between the two remain uncertain.ObjectiveWe determined the impact of residential traffic on mortality during treatment of active TB.MethodsFrom 2000-2012, we enrolled 32,875 patients in California with active TB and followed them throughout treatment. We obtained patient data from the California Tuberculosis Registry and calculated traffic volumes and traffic densities in 100- to 400-m radius buffers around residential addresses. We used Cox models to determine mortality hazard ratios, controlling for demographic, socioeconomic, and clinical potential confounders. We categorized traffic exposures as quintiles and determined trends using Wald tests.ResultsParticipants contributed 22,576 person-years at risk. There were 2,305 deaths during treatment for a crude mortality rate of 1,021 deaths per 10,000 person-years. Traffic volumes and traffic densities in all buffers around patient residences were associated with increased mortality during TB treatment, although the findings were not statistically significant in all buffers. As the buffer size decreased, fifth-quintile mortality hazards increased, and trends across quintiles of traffic exposure became more statistically significant. Increasing quintiles of nearest-road traffic volumes in the 100-m buffer were associated with 3%, 14%, 19%, and 28% increased risk of death during TB treatment [first quintile, referent; second quintile hazard ratio (HR)=1.03 [95% confidence interval (CI): 0.86, 1.25]; third quintile HR=1.14 (95% CI: 0.95, 1.37); fourth quintile HR=1.19 (95% CI: 0.99, 1.43); fifth quintile HR=1.28 (95% CI: 1.07, 1.53), respectively; p-trend=0.002].ConclusionsResidential proximity to road traffic volumes and traffic density were associated with increased all-cause mortality in patients undergoing treatment for active tuberculosis even after adjusting for multiple demographic, socioeconomic, and clinical factors, suggesting that TB patients are susceptible to the adverse health effects of traffic-related air pollution. https://doi.org/10.1289/EHP1699
Seeking a Better Solution for the Disposition of Frozen Embryos: Is Embryo Adoption the Answer
VAST: An ASKAP Survey for Variables and Slow Transients
The Australian Square Kilometre Array Pathfinder (ASKAP) will give us an
unprecedented opportunity to investigate the transient sky at radio
wavelengths. In this paper we present VAST, an ASKAP survey for Variables and
Slow Transients. VAST will exploit the wide-field survey capabilities of ASKAP
to enable the discovery and investigation of variable and transient phenomena
from the local to the cosmological, including flare stars, intermittent
pulsars, X-ray binaries, magnetars, extreme scattering events, interstellar
scintillation, radio supernovae and orphan afterglows of gamma ray bursts. In
addition, it will allow us to probe unexplored regions of parameter space where
new classes of transient sources may be detected. In this paper we review the
known radio transient and variable populations and the current results from
blind radio surveys. We outline a comprehensive program based on a multi-tiered
survey strategy to characterise the radio transient sky through detection and
monitoring of transient and variable sources on the ASKAP imaging timescales of
five seconds and greater. We also present an analysis of the expected source
populations that we will be able to detect with VAST.Comment: 29 pages, 8 figures. Submitted for publication in Pub. Astron. Soc.
Australi
Gas-rich, field ultra-diffuse galaxies host few globular clusters
We present Hubble Space Telescope imaging of 14 gas-rich, low surface
brightness and ultra-diffuse galaxies (UDGs) in the field at distances of 25-36
Mpc. An inspection of point-like sources brighter than the turnover magnitude
of the globular cluster luminosity function and within twice the half-light
radii of each galaxy reveals that, unlike those in denser environments,
gas-rich, field UDGs host very few old globular clusters (GCs). Most of the
targets (nine) have zero candidate GCs, with the remainder having one or two
candidates each. These findings are broadly consistent with expectations for
normal dwarf galaxies of similar stellar mass. This rules out gas-rich, field
UDGs as potential progenitors of the GC-rich UDGs that are typically found in
galaxy clusters. However, some in galaxy groups may be directly accreted from
the field. In line with other recent results, this strongly suggests that there
must be at least two distinct formation pathways for UDGs, and that this
sub-population is simply an extreme low surface brightness extension of the
underlying dwarf galaxy population. The root cause of their diffuse stellar
distributions remains unclear, but the formation mechanism appears to only
impact the distribution of stars (and potentially dark matter), without
strongly impacting the distribution of neutral gas, the overall stellar mass,
or the number of GCs.Comment: Submitted to AAS journal
Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).
Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)
Gas and Star Formation in Satellites of Milky Way Analogs
We have imaged the entirety of eight (plus one partial) Milky Way (MW)–like satellite systems, a total of 42 (45) satellites, from the Satellites Around Galactic Analogs II catalog in both Hα and H i with the Canada–France–Hawaii Telescope and the Jansky Very Large Array. In these eight systems we have identified four cases where a satellite appears to be currently undergoing ram pressure stripping (RPS) as its H i gas collides with the circumgalactic medium (CGM) of its host. We also see a clear suppression of gas fraction (M HI/M *) with decreasing (projected) satellite–host separation—to our knowledge, the first time this has been observed in a sample of MW-like systems. Comparisons to the Auriga, A Project Of Simulating The Local Environment, and TNG50 cosmological zoom-in simulations show consistent global behavior, but they systematically underpredict gas fractions across all satellites by roughly 0.5 dex. Using a simplistic RPS model, we estimate the average peak CGM density that satellites in these systems have encountered to be logρcgm/gcm−3≈−27.3 . Furthermore, we see tentative evidence that these satellites are following a specific star formation rate to gas fraction relation that is distinct from field galaxies. Finally, we detect one new gas-rich satellite in the UGC 903 system with an optical size and surface brightness meeting the standard criteria to be considered an ultra-diffuse galaxy
The Faint Satellite System of NGC 253: Insights into Low-Density Environments and No Satellite Plane
We have conducted a systematic search around the Milky Way (MW) analog NGC
253 (D=3.5 Mpc), as a part of the Panoramic Imaging Survey of Centaurus and
Sculptor (PISCeS) - a Magellan+Megacam survey to identify dwarfs and other
substructures in resolved stellar light around MW-mass galaxies outside of the
Local Group. In total, NGC 253 has five satellites identified by PISCeS within
100 kpc with an absolute V-band magnitude . We have additionally
obtained deep Hubble Space Telescope imaging of four reported candidates beyond
the survey footprint: Do III, Do IV, and dw0036m2828 are confirmed to be
satellites of NGC 253, while SculptorSR is found to be a background galaxy. We
find no convincing evidence for the presence of a plane of satellites
surrounding NGC 253. We construct its satellite luminosity function, which is
complete down to out to 100 kpc and out
to 300 kpc, and compare it to those calculated for other Local Volume galaxies.
Exploring trends in satellite counts and star-forming fractions among satellite
systems, we find relationships with host stellar mass, environment, and
morphology, pointing to a complex picture of satellite formation, and a
successful model has to reproduce all of these trends.Comment: Submitted to AAS Journal. Comments are welcom
1936 The Freshman, vol. 3, no. 3
The Freshman was a weekly, student newsletter issued on Mondays throughout the academic year. The newsletter included calendar notices, coverage of campus social events, lectures, and athletic teams. The intent of the publication was to create unity, a sense of community, and class spirit among first year students. The paper includes a report on construction of Memorial Gymnasium on the south side of the Armory
1936 The Freshman, vol. 3, no. 19
The Freshman was a weekly, student newsletter issued on Mondays throughout the academic year. The newsletter included calendar notices, coverage of campus social events, lectures, and athletic teams. The intent of the publication was to create unity, a sense of community, and class spirit among first year students. Featured in this issue is a memoriam dedicated to Carlton Otis Wilson (1913-1933), killed when he was struck from behind by a speeding vehicle
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