4,729 research outputs found
Executive Summary: Diagnosis and Management of Prosthetic Joint Infection: Clinical Practice Guidelines by the Infectious Diseases Society of Americaa
These guidelines are intended for use by infectious disease specialists, orthopedists, and other healthcare professionals who care for patients with prosthetic joint infection (PJI). They include evidence-based and opinion-based recommendations for the diagnosis and management of patients with PJI treated with debridement and retention of the prosthesis, resection arthroplasty with or without subsequent staged reimplantation, 1-stage reimplantation, and amputatio
Keck spectroscopy and Spitzer Space Telescope analysis of the outer disk of the Triangulum Spiral Galaxy M33
In an earlier study of the spiral galaxy M33, we photometrically identified
arcs or outer spiral arms of intermediate age (0.6 Gyr - 2 Gyr) carbon stars
precisely at the commencement of the HI-warp. Stars in the arcs were
unresolved, but were likely thermally-pulsing asymptotic giant branch carbon
stars. Here we present Keck I spectroscopy of seven intrinsically bright and
red target stars in the outer, northern arc in M33. The target stars have
estimated visual magnitudes as faint as V \sim 25 mag. Absorption bands of CN
are seen in all seven spectra reported here, confirming their carbon star
status. In addition, we present Keck II spectra of a small area 0.5 degree away
from the centre of M33; the target stars there are also identified as carbon
stars. We also study the non-stellar PAH dust morphology of M33 secured using
IRAC on board the Spitzer Space Telescope. The Spitzer 8 micron image attests
to a change of spiral phase at the start of the HI warp. The Keck spectra
confirm that carbon stars may safely be identified on the basis of their red
J-K_s colours in the outer, low metallicity disk of M33. We propose that the
enhanced number of carbon stars in the outer arms are an indicator of recent
star formation, fueled by gas accretion from the HI-warp reservoir.Comment: 9 pages, 5 figures, accepted in A&
Morphologies of High Redshift, Dust Obscured Galaxies from Keck Laser Guide Star Adaptive Optics
Spitzer MIPS images in the Bootes field of the NOAO Deep Wide-Field Survey
have revealed a class of extremely dust obscured galaxy (DOG) at z~2. The DOGs
are defined by very red optical to mid-IR (observed-frame) colors, R - [24 um]
> 14 mag, i.e. f_v (24 um) / f_v (R) > 1000. They are Ultra-Luminous Infrared
Galaxies with L_8-1000 um > 10^12 -10^14 L_sun, but typically have very faint
optical (rest-frame UV) fluxes. We imaged three DOGs with the Keck Laser Guide
Star Adaptive Optics (LGSAO) system, obtaining ~0.06'' resolution in the
K'-band. One system was dominated by a point source, while the other two were
clearly resolved. Of the resolved sources, one can be modeled as a exponential
disk system. The other is consistent with a de Vaucouleurs profile typical of
elliptical galaxies. The non-parametric measures of their concentration and
asymmetry, show the DOGs to be both compact and smooth. The AO images rule out
double nuclei with separations of greater than 0.1'' (< 1 kpc at z=2), making
it unlikely that ongoing major mergers (mass ratios of 1/3 and greater) are
triggering the high IR luminosities. By contrast, high resolution images of z~2
SCUBA sources tend to show multiple components and a higher degree of
asymmetry. We compare near-IR morphologies of the DOGs with a set of z=1
luminous infrared galaxies (LIRGs; L_IR ~ 10^11 L_sun) imaged with Keck LGSAO
by the Center for Adaptive Optics Treasury Survey. The DOGs in our sample have
significantly smaller effective radii, ~1/4 the size of the z=1 LIRGs, and tend
towards higher concentrations. The small sizes and high concentrations may help
explain the globally obscured rest-frame blue-to-UV emission of the DOGs.Comment: 9 pages, 7 figures, 2 tables, accepted for publication in the
Astronomical Journa
Implementation of Clifford gates in the Ising-anyon topological quantum computer
We give a general proof for the existence and realizability of Clifford gates
in the Ising topological quantum computer. We show that all quantum gates that
can be implemented by braiding of Ising anyons are Clifford gates. We find that
the braiding gates for two qubits exhaust the entire two-qubit Clifford group.
Analyzing the structure of the Clifford group for n \geq 3 qubits we prove that
the the image of the braid group is a non-trivial subgroup of the Clifford
group so that not all Clifford gates could be implemented by braiding in the
Ising topological quantum computation scheme. We also point out which Clifford
gates cannot in general be realized by braiding.Comment: 17 pages, 10 figures, RevTe
Spitzer-IRS Study of the Antennae Galaxies NGC 4038/39
Using the Infrared Spectrograph on the Spitzer Space Telescope, we observed
the Antennae galaxies obtaining spectral maps of the entire central region and
high signal-to-noise 5-38 um spectra of the two galactic nuclei and six
infrared-luminous regions. The total infrared luminosity of our six IR peaks
plus the two nuclei is L_IR = 3.8x10^10 L_o, with their derived star formation
rates ranging between 0.2 and 2 M_o/yr, with a total of 6.6 M_o/yr. The hardest
and most luminous radiation originates from two compact clusters in the
southern part of the overlap region, which also have the highest dust
temperatures. PAH emission and other tracers of softer radiation are spatially
extended throughout and beyond the overlap region, but regions with harder and
intenser radiation field show a reduced PAH strength. The strong H_2 emission
is rather confined around the nucleus of NGC 4039, where shocks appear to be
the dominant excitation mechanism, and the southern part of the overlap region,
where it traces the most recent starburst activity. The luminosity ratio
between the warm molecular gas (traced by the H_2 lines) and the total far-IR
emission is ~1.6x10^-4, similar to that found in many starburst and ULIRGs. The
total mass of warm H_2 in the Antennae is 2.5x10^7 M_o, with a fraction of warm
to total H_2 gas mass of about 0.35%. The average warm H_2 temperature is
302+/-26 K and appears anti-correlated with the radiation field hardness,
possibly due to an evolution of the PDR morphology. The previously reported
tight correlation between the H_2 and PAH emission was not found but higher
total PAH emission to continuum ratios were found in PDRs with warmer gas.Comment: 24 pages, 13 figures, accepted by ApJ, full resolution version at
http://www.strw.leidenuniv.nl/~brandl/ngc4038_brandl.pd
High Mass Star Formation I: The Mass Distribution of Submillimeter Clumps in NGC 7538
We present submillimeter continuum maps at 450 and 850 microns of a 12 x 8
arcminute region of the NGC 7538 high-mass star-forming region, made using the
Submillimeter Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell
Telescope. We used an automated clump-finding algorithm to identify 67 clumps
in the 450 micron image and 77 in the 850 micron image. Contrary to previous
studies, we find a positive correlation between high spectral index, alpha, and
high submillimeter flux, with the difference being accounted for by different
treatments of the error beam. We interpret the higher spectral index at
submillimeter peaks as a reflection of elevated dust temperature, particularly
when there is an embedded infrared source, though it may also reflect changing
dust properties. The clump mass-radius relationship is well-fit by a power law
of the form M \propto R^(-x) with x = 1.5-2.1, consistent with theories of
turbulently-supported clumps. According to our most reliable analysis, the
high-mass end (approx. 100-2700 M_sun) of the submillimeter clump mass function
in NGC 7538 follows a Salpeter-like power law with index 2.0 +/- 0.3. This
result agrees well with similar studies of lower-mass regions rho Oph and Orion
B. We interpret the apparent invariance of the shape of the clump mass function
over a broad range of parent cloud masses as evidence for the self-similarity
of the physical processes which determine it. This result is consistent with
models which suggest that turbulent fragmentation, acting at early times, is
sufficient to set the clump mass function.Comment: 37 pages, 7 figures, accepted for publication in Ap
Reanalysis of single-cell RNA sequencing data does not support herpes simplex virus 1 latency in non-neuronal ganglionic cells in mice
Most individuals are latently infected with herpes simplex virus type 1 (HSV-1), and it is well-established that HSV-1 establishes latency in sensory neurons of peripheral ganglia. However, it was recently proposed that latent HSV-1 is also present in immune cells recovered from the ganglia of experimentally infected mice. Here, we reanalyzed the single-cell RNA sequencing (scRNA-Seq) data that formed the basis for that conclusion. Unexpectedly, off-target priming in 3’ scRNA-Seq experiments enabled the detection of non-polyadenylated HSV-1 latency-associated transcript (LAT) intronic RNAs. However, LAT reads were near-exclusively detected in mixed populations of cells undergoing cell death. Specific loss of HSV-1 LAT and neuronal transcripts during quality control filtering indicated widespread destruction of neurons, supporting the presence of contaminating cell-free RNA in other cells following tissue processing. In conclusion, the reported detection of latent HSV-1 in non-neuronal cells is best explained using compromised scRNA-Seq datasets. IMPORTANCE Most people are infected with herpes simplex virus type 1 (HSV-1) during their life. Once infected, the virus generally remains in a latent (silent) state, hiding within the neurons of peripheral ganglia. Periodic reactivation (reawakening) of the virus may cause fresh diseases such as cold sores. A recent study using single-cell RNA sequencing (scRNA-Seq) proposed that HSV-1 can also establish latency in the immune cells of mice, challenging existing dogma. We reanalyzed the data from that study and identified several flaws in the methodologies and analyses performed that invalidate the published conclusions. Specifically, we showed that the methodologies used resulted in widespread destruction of neurons which resulted in the presence of contaminants that confound the data analysis. We thus conclude that there remains little to no evidence for HSV-1 latency in immune cells.</p
Reanalysis of single-cell RNA sequencing data does not support herpes simplex virus 1 latency in non-neuronal ganglionic cells in mice
Most individuals are latently infected with herpes simplex virus type 1 (HSV-1), and it is well-established that HSV-1 establishes latency in sensory neurons of peripheral ganglia. However, it was recently proposed that latent HSV-1 is also present in immune cells recovered from the ganglia of experimentally infected mice. Here, we reanalyzed the single-cell RNA sequencing (scRNA-Seq) data that formed the basis for that conclusion. Unexpectedly, off-target priming in 3’ scRNA-Seq experiments enabled the detection of non-polyadenylated HSV-1 latency-associated transcript (LAT) intronic RNAs. However, LAT reads were near-exclusively detected in mixed populations of cells undergoing cell death. Specific loss of HSV-1 LAT and neuronal transcripts during quality control filtering indicated widespread destruction of neurons, supporting the presence of contaminating cell-free RNA in other cells following tissue processing. In conclusion, the reported detection of latent HSV-1 in non-neuronal cells is best explained using compromised scRNA-Seq datasets. IMPORTANCE Most people are infected with herpes simplex virus type 1 (HSV-1) during their life. Once infected, the virus generally remains in a latent (silent) state, hiding within the neurons of peripheral ganglia. Periodic reactivation (reawakening) of the virus may cause fresh diseases such as cold sores. A recent study using single-cell RNA sequencing (scRNA-Seq) proposed that HSV-1 can also establish latency in the immune cells of mice, challenging existing dogma. We reanalyzed the data from that study and identified several flaws in the methodologies and analyses performed that invalidate the published conclusions. Specifically, we showed that the methodologies used resulted in widespread destruction of neurons which resulted in the presence of contaminants that confound the data analysis. We thus conclude that there remains little to no evidence for HSV-1 latency in immune cells.</p
Iron Status and Analysis of Efficacy and Safety of Ferric Carboxymaltose Treatment in Patients with Inflammatory Bowel Disease
Background and Aims:We analyzed iron deficiency and the therapeutic response following intravenous ferric carboxymaltose in a large single-center inflammatory bowel disease (IBD) cohort. Methods: 250 IBD patients were retrospectively analyzed for iron deficiency and iron deficiency anemia. A subgroup was analyzed regarding efficacy and side effects of iron supplementation with ferric carboxymaltose. Results: In the cohort (n = 250), 54.4% of the patients had serum iron levels 60 mu g/dl, 61.6% had ferritin >100 ng/ml, and 90.7% reached Hb >12/13 g/dl at follow-up (p < 0.0001 for all parameters vs. pretreatment values). The most frequent adverse event was a transient increase of liver enzymes with male gender as risk factor (p = 0.008, OR 8.62, 95% CI 1.74-41.66). Conclusions: Iron deficiency and anemia are frequent in IBD patients. Treatment with ferric carboxymaltose is efficious, safe and well tolerated in iron-deficient IBD patients. Copyright (C) 2011 S. Karger AG, Base
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