24,136 research outputs found
Heterotic T-Duality and the Renormalization Group
We consider target space duality transformations for heterotic sigma models
and strings away from renormalization group fixed points. By imposing certain
consistency requirements between the T-duality symmetry and renormalization
group flows, the one loop gauge beta function is uniquely determined, without
any diagram calculations. Classical T-duality symmetry is a valid quantum
symmetry of the heterotic sigma model, severely constraining its
renormalization flows at this one loop order. The issue of heterotic anomalies
and their cancelation is addressed from this duality constraining viewpoint.Comment: 17 pages, Late
ICD-9-CM coding for multidrug resistant infection correlates poorly with microbiologically confirmed multidrug resistant infection
Differences in mortality between infections due to extended-spectrum-beta-lactamase–producing Klebsiella pneumoniae and Escherichia coli
Readmissions with multidrug-resistant infection in patients with prior multidrug resistant infection
OBJECTIVETo determine incidence of and risk factors for readmissions with multidrug-resistant organism (MDRO) infections among patients with previous MDRO infection.DESIGNRetrospective cohort of patients admitted between January 1, 2006, and October 1, 2015.SETTINGBarnes-Jewish Hospital, a 1,250-bed academic tertiary referral center in St Louis, Missouri.METHODSWe identified patients with MDROs obtained from the bloodstream, bronchoalveolar lavage (BAL)/bronchial wash, or other sterile sites. Centers for Disease Control and prevention (CDC) and European CDC definitions of MDROs were utilized. All readmissions ≤1 year from discharge from the index MDRO hospitalization were evaluated for bloodstream, BAL/bronchial wash, or other sterile site cultures positive for the same or different MDROs.RESULTSIn total, 4,429 unique patients had a positive culture for an MDRO; 3,453 of these (78.0%) survived the index hospitalization. Moreover, 2,127 patients (61.6%) were readmitted ≥1 time within a year, for a total of 5,849 readmissions. Furthermore, 512 patients (24.1%) had the same or a different MDRO isolated from blood, BAL/bronchial wash, or another sterile site during a readmission. Bone marrow transplant, end-stage renal disease, lymphoma, methicillin-resistant Staphylococcus aureus, or carbapenem-resistant Pseudomonas aeruginosa during index hospitalization were factors associated with increased risk of having an MDRO isolated during a readmission. MDROs isolated during readmissions were in the same class of MDRO as the index hospitalization 9%–78% of the time, with variation by index pathogen.CONCLUSIONSReadmissions among patients with MDRO infections are frequent. Various patient and organism factors predispose to readmission. When readmitted patients had an MDRO, it was often a pathogen in the same class as that isolated during the index admission, with the exception of Acinetobacter (~9%).Infect Control Hosp Epidemiol 2018;39:12–19</jats:sec
Development of a second generation prototype reflectometer for reflectance measurement in space Final technical report
Prototype reflectometer development for reflection measurements in spac
vbyCaHbeta CCD Photometry of Clusters. VI. The Metal-Deficient Open Cluster NGC 2420
CCD photometry on the intermediate-band vbyCaHbeta system is presented for
the metal-deficient open cluster, NGC 2420. Restricting the data to probable
single members of the cluster using the CMD and the photometric indices alone
generates a sample of 106 stars at the cluster turnoff. The average E(b-y) =
0.03 +/- 0.003 (s.e.m.) or E(B-V) = 0.050 +/- 0.004 (s.e.m.), where the errors
refer to internal errors alone. With this reddening, [Fe/H] is derived from
both m1 and hk, using b-y and Hbeta as the temperature index. The agreement
among the four approaches is reasonable, leading to a final weighted average of
[Fe/H] = -0.37 +/- 0.05 (s.e.m.) for the cluster, on a scale where the Hyades
has [Fe/H] = +0.12. When combined with the abundances from DDO photometry and
from recalibrated low-resolution spectroscopy, the mean metallicity becomes
[Fe/H] = -0.32 +/- 0.03. It is also demonstrated that the average cluster
abundances based upon either DDO data or low-resolution spectroscopy are
consistently reliable to 0.05 dex or better, contrary to published attempts to
establish an open cluster metallicity scale using simplistic offset corrections
among different surveys.Comment: scheduled for Jan. 2006 AJ; 33 pages, latex, includes 7 figures and 2
table
Infectious diseases consultation reduces 30-day and 1-year all-cause mortality for multidrug-resistant organism infections
Abstract
Background
Multidrug-resistant organism (MDRO) infections are associated with high mortality and readmission rates. Infectious diseases (ID) consultation improves clinical outcomes for drug-resistant Staphylococcus aureus bloodstream infections. Our goal was to determine the association between ID consultation and mortality following various MDRO infections.
Methods
This study was conducted with a retrospective cohort (January 1, 2006–October 1, 2015) at an academic tertiary referral center. We identified patients with MDROs in a sterile site or bronchoalveolar lavage/bronchial wash culture. Mortality and readmissions within 1 year of index culture were identified, and the association of ID consultation with these outcomes was determined using Cox proportional hazards models with inverse weighting by the propensity score for ID consultation.
Results
A total of 4214 patients with MDRO infections were identified. ID consultation was significantly associated with reductions in 30-day and 1-year mortality for resistant S. aureus (hazard ratio [HR], 0.48; 95% confidence interval [CI], 0.36–0.63; and HR, 0.73, 95% CI, 0.61–0.86) and Enterobacteriaceae (HR, 0.41; 95% CI, 0.27–0.64; and HR, 0.74; 95% CI, 0.59–0.94), and 30-day mortality for polymicrobial infections (HR, 0.51; 95% CI, 0.31–0.86) but not Acinetobacter or Pseudomonas. For resistant Enterococcus, ID consultation was marginally associated with decreased 30-day mortality (HR, 0.81; 95% CI, 0.62–1.06). ID consultation was associated with reduced 30-day readmission for resistant Enterobacteriaceae.
Conclusions
ID consultation was associated with significant reductions in 30-day and 1-year mortality for resistant S. aureus and Enterobacteriaceae, and 30-day mortality for polymicrobial infections. There was no association between ID consultation and mortality for patients with resistant Pseudomonas, Acinetobacter, or Enterococcus, possibly due to small sample sizes. Our results suggest that ID consultation may be beneficial for patients with some MDRO infections.
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vbyCaHbeta CCD Photometry of Clusters. VIII. The Super-Metal Rich, Old Open Cluster NGC 6791
CCD photometry on the intermediate-band vbyCaHbeta system is presented for
the metal-rich, old open cluster, NGC 6791. Preliminary analysis led to [Fe/H]
above +0.4 with an anomalously high reddening and an age below 5 Gyr. A revised
calibration between (b-y)_0 and [Fe/H] at a given temperature shows that the
traditional color-metallicity relations underestimate the color of the turnoff
stars at high metallicity. With the revised relation, the metallicity from hk
and the reddening for NGC 6791 become [Fe/H] = +0.45 +/- 0.04 and E(b-y) =
0.113 +/- 0.012 or E(B-V) = 0.155 +/- 0.016. Using the same technique,
reanalysis of the photometry for NGC 6253 produces [Fe/H] = +0.58 +/-0.04 and
E(b-y) = 0.120 +/- 0.018 or E(B-V) = 0.160 +/- 0.025. The errors quoted include
both the internal and external errors. For NGC 6791, the metallicity from m_1
is a factor of two below that from hk, a result that may be coupled to the
consistently low metal abundance from DDO photometry of the cluster and the
C-deficiency found from high dispersion spectroscopy. E(B-V) is the same value
predicted from Galactic reddening maps. With E(B-V) = 0.15 and [Fe/H] = +0.45,
the available isochrones predict an age of 7.0 +/- 1.0 Gyr and an apparent
modulus of (m-M) = 13.60 +/- 0.15, with the dominant source of the uncertainty
arising from inconsistencies among the isochrones. The reanalysis of NGC 6253
with the revised lower reddening confirms that on both the hk and m_1
metallicity scales, NGC 6253, while less than half the age of NGC 6791, remains
at least as metal-rich as NGC 6791, if not richer.Comment: Accepted for Astronomical Journal. 42 p. latex file includes 11
figures and 3 tables, one of which is a short version of a data table to
appear in online AJ in its entiret
Monopole Vector Spherical Harmonics
Eigenfunctions of total angular momentum for a charged vector field
interacting with a magnetic monopole are constructed and their properties
studied. In general, these eigenfunctions can be obtained by applying vector
operators to the monopole spherical harmonics in a manner similar to that often
used for the construction of the ordinary vector spherical harmonics. This
construction fails for the harmonics with the minimum allowed angular momentum.
These latter form a set of vector fields with vanishing covariant curl and
covariant divergence, whose number can be determined by an index theorem.Comment: 21 pages, CU-TP-60
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