Cosmic rays travelling through interstellar space have their propagation
directions repeatedly scattered by fluctuating interstellar magnetic fields.
The nature of this scattering is a major unsolved ...problem in astrophysics, one
that has resisted solution largely due to a lack of direct observational
constraints on the scattering rate. Here we show that very high-energy
$\gamma$-ray emission from the globular cluster Terzan 5, which has
unexpectedly been found to be displaced from the cluster, presents a direct
probe of this process. We show that this displacement is naturally explained by
cosmic rays accelerated in the bow shock around the cluster propagating a
finite distance before scattering processes re-orient enough of them towards
Earth to produce a detectable $\gamma$-ray signal. The angular distance between
the cluster and the signal places tight constraints on the scattering rate,
which we show are consistent with a model whereby scattering is primarily due
to excitation of magnetic waves by the cosmic rays themselves. The analysis
method we develop here will make it possible to use sources with similarly
displaced non-thermal X-ray and TeV $\gamma$-ray signals as direct probes of
cosmic ray scattering across a range of Galactic environments.
Undoubtedly, the economic burden of cardiac care will continue to rise because of the rising costs of cardiac technological advances (3) and the increasing prevalence of cardiac disease (4). ...we ...can expect that public and private payers will increase their focus on both improving the quality and efficiency of cardiac care. There are essentially no randomized controlled trials demonstrating the effectiveness of P4P programs and very few reports in the literature that analyze the existing programs (5,11-14). Because of the lack of health services research and solid supporting evidence regarding P4P programs, the ACC and other organizations (15-18) have developed principles to guide their members and payers through the transition to novel payment mechanisms.
We study rapidly accreting, gravitationally unstable disks with a series of idealized global, numerical experiments using the code ORION. Our numerical parameter study focuses on protostellar disks, ...showing that one can predict disk behavior and the multiplicity of the accreting star system as a function of two dimensionless parameters which compare the infall rate to the disk sound speed and orbital period. Although gravitational instabilities become strong, we find that fragmentation into binary or multiple systems occurs only when material falls in several times more rapidly than the canonical isothermal limit. The disk-to-star accretion rate is proportional to the infall rate and governed by gravitational torques generated by low-m spiral modes. Furthermore, we also confirm the existence of a maximum stable disk mass: disks that exceed ~50% of the total system mass are subject to fragmentation and the subsequent formation of binary companions.
What has become apparent from the rosiglitazone saga is that the impact of newer glucose lowering agents on cardiovascular disease is impossible to predict from their effects on surrogate end ...points-something which also invalidates many of the conclusions from cost-benefit estimates. ...patients who have these drugs recommended should be told...
Cretaceous rock formations have been shown to harbor extant sulfate-reducing microbial communities. At these sites, microbial activity is concentrated at rock interfaces where there is likely a ...diffusion of nutrients from low permeability organic rich shales to higher permeability sandstones. This study was undertaken to further characterize this process and to determine the components of shale that provide electron donors for sulfate reduction activity. To this end, samples of Cretaceous sandstones were incubated with ground shales from available depths at the Cerro Negro exploratory drilling site in northwestern New Mexico. Both sulfate consumption as an indicator of sulfate reduction and acetate production were stimulated in the sandstone-shale incubations. The greatest levels of stimulation were observed with shales originally closest to the lower sandstone-shale interface and a strong correlation was observed between shale organic carbon and microbial activity. These results suggested that the organic matter in shale was supplying the needed electron donor for the sulfate-reducing microbial community. Further evidence for this interpretation was provided when a pure culture of Acetobacterium psammolithicum , an acetogen isolated from this site, was stimulated to produce acetate by the addition of autoclaved shales. To investigate the components in shale that were responsible for stimulating microbial activity, we extracted shale organic material. Aqueous extracts and to a lesser extent neutral ether extractions stimulated activity although neither to the same extent as the shale itself. Alkaline aqueous extracts were fractionated using XAD-7 resin. Each of the fractions contributed to some degree, but the greatest stimulation in microbial activity was attributed to both the hydrophilic eluate and to the fulvic acid fraction. These data indicate that a relatively complex group of organic compounds supply electron donors to the sandstone microbial communities.
ABSTRACT
We examined the relative roles of acetogenic and sulfate-reducing bacteria in H
2
consumption in a previously characterized subsurface sandstone ecosystem. Enrichment cultures originally ...inoculated with ground sandstone material obtained from a Cretaceous formation in central New Mexico were grown with hydrogen in a mineral medium supplemented with 0.02% yeast extract. Sulfate reduction and acetogenesis occurred in these cultures, and the two most abundant organisms carrying out the reactions were isolated. Based on 16S rRNA analysis data and on substrate utilization patterns, these organisms were named
Desulfomicrobium hypogeium
sp. nov. and
Acetobacterium psammolithicum
sp. nov. The steady-state H
2
concentrations measured in sandstone-sediment slurries (threshold concentration, 5 nM), in pure cultures of sulfate reducers (threshold concentration, 2 nM), and in pure cultures of acetogens (threshold concentrations 195 to 414 nM) suggest that sulfate reduction is the dominant terminal electron-accepting process in the ecosystem examined. In an experiment in which direct competition for H
2
between
D. hypogeium
and
A. psammolithicum
was examined, sulfate reduction was the dominant process.
Carbon monoxide (CO) provides crucial information about the molecular gas
properties of galaxies. While $^{12}$CO has been targeted extensively,
isotopologues such as $^{13}$CO have the advantage of ...being less optically
thick and observations have recently become accessible across full galaxy
discs. We present a comprehensive new dataset of $^{13}$CO(1-0) observations
with the IRAM 30-m telescope of the full discs of 9 nearby spiral galaxies from
the EMPIRE survey at a spatial resolution of $\sim$1.5kpc. $^{13}$CO(1-0) is
mapped out to $0.7-1r_{25}$ and detected at high signal-to-noise throughout our
maps. We analyse the $^{12}$CO(1-0)-to-$^{13}$CO(1-0) ratio ($\Re$) as a
function of galactocentric radius and other parameters such as the
$^{12}$CO(2-1)-to-$^{12}$CO(1-0) intensity ratio, the 70-to-160$\mu$m flux
density ratio, the star-formation rate surface density, the star-formation
efficiency, and the CO-to-H$_2$ conversion factor. We find that $\Re$ varies by
a factor of 2 at most within and amongst galaxies, with a median value of 11
and larger variations in the galaxy centres than in the discs. We argue that
optical depth effects, most likely due to changes in the mixture of
diffuse/dense gas, are favored explanations for the observed $\Re$ variations,
while abundance changes may also be at play. We calculate a spatially-resolved
$^{13}$CO(1-0)-to-H$_2$ conversion factor and find an average value of
$1.0\times10^{21}$ cm$^{-2}$ (K.km/s)$^{-1}$ over our sample with a standard
deviation of a factor of 2. We find that $^{13}$CO(1-0) does not appear to be a
good predictor of the bulk molecular gas mass in normal galaxy discs due to the
presence of a large diffuse phase, but it may be a better tracer of the mass
than $^{12}$CO(1-0) in the galaxy centres where the fraction of dense gas is
larger.
Racial differences in reperfusion therapy use among patients hospitalized with myocardial infarction (MI) have been previously reported as national phenomenon. However, it is unclear whether racial ...differences in treatment vary by region.
Using data from the National Registry of Myocardial Infarction-2 and -3, a cohort of patients hospitalized with MI in the United States between 1994 and 2000, we sought to determine whether racial differences in reperfusion therapy use varied by geographic region in patients eligible for reperfusion therapy with no clinical contraindications to treatment (n = 204230).
Black patients had lower crude rates of reperfusion therapy than white patients (66.5% vs 69.9%, −3.3% racial difference, 99% CI −4.4% to −2.2%) overall. However, racial differences in reperfusion therapy use varied by geographic region. Reperfusion therapy rates were similar for black patients and white patients in the Northeast (67.9% black vs 65.3% white, +2.7% racial difference, 99% CI −0.5% to 5.8%) and statistically comparable for patients in the Midwest (68.3% black vs 69.0% white, −0.7% racial difference, 99% CI −2.9% to 1.5%) and West (70.7% black vs 72.6% white, −1.9% racial difference, 99% CI −5.1% to 1.2%). Racial differences in reperfusion therapy use were greatest for patients hospitalized in the South (64.5% black vs 71.7% white, −7.1% racial difference, 99% CI −8.7% to −5.6%). Racial differences were reduced, but geographic variations in racial differences persisted after multivariable adjustment.
Lower rates of reperfusion therapy use among black patients with MI do not reflect a national pattern of racial differences in treatment, but a practice pattern predominantly attributable to the South.
Increased global connectivity has catalyzed technological development in almost all industries, in part through the facilitation of novel collaborative structures. Notably, open innovation and ...crowd-sourcing-of expertise and/or funding-has tremendous potential to increase the efficiency with which biomedical ecosystems interact to deliver safe, efficacious and affordable therapies to patients. Consequently, such practices offer tremendous potential in advancing development of cellular therapies. In this vein, the CASMI Translational Stem Cell Consortium (CTSCC) was formed to unite global thought-leaders, producing academically rigorous and commercially practicable solutions to a range of challenges in pluripotent stem cell translation. Critically, the CTSCC research agenda is defined through continuous consultation with its international funding and research partners. Herein, initial findings for all research focus areas are presented to inform global product development strategies, and to stimulate continued industry interaction around biomanufacturing, strategic partnerships, standards, regulation and intellectual property and clinical adoption.
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