915 research outputs found
Incidence, risk factors and outcomes of Escherichia coli bloodstream infections in a large Canadian region
ABSTRACTAlthough Escherichia coli is the most common cause of bloodstream infection, its epidemiology has not been well defined in non-selected populations. We sought to describe the incidence of risk factors for, and outcomes associated with, E. coli bacteraemia. Population-based surveillance for E. coli bacteraemia was conducted in the Calgary Health Region (population 1.2 million) during the period 2000â2006. In total, 2368 episodes of E. coli bacteraemia were identified for an overall annual population incidence of 30.3/100 000; 15% were nosocomial, 32% were healthcare-associated community-onset and 53% were community-acquired bacteraemias. The very young and the elderly were at highest risk for E. coli bacteraemia. Sixty per cent of the episodes occurred in females (relative risk 1.5; 95% CI 1.4â1.6). Dialysis, solid organ transplantation and neoplastic disease were the most important risk factors for acquiring E. coli bacteraemia. Rates of resistance to ampicillin, trimethoprimâsulphamethoxazole, gentamicin, ciprofloxacin, cefazolin and ceftriaxone increased significantly during the period 2000â2006. The case-fatality rate was 11% and the annual population mortality rate was 2.9/100 000. Increasing age, ciprofloxacin resistance, non-urinary focus and a number of comorbid illnesses were independently associated with an increased risk of death, and community acquisition and urinary focus were associated with a lower risk of death. This study documents the major burden of illness associated with E. coli bacteraemia and identifies groups at increased risk for acquiring and dying from these infections. The emergence of ciprofloxacin resistance and its adverse effect on patient outcome is a major concern
Domain wall mobility in nanowires: transverse versus vortex walls
The motion of domain walls in ferromagnetic, cylindrical nanowires is
investigated numerically by solving the Landau-Lifshitz-Gilbert equation for a
classical spin model in which energy contributions from exchange, crystalline
anisotropy, dipole-dipole interaction, and a driving magnetic field are
considered. Depending on the diameter, either transverse domain walls or vortex
walls are found. The transverse domain wall is observed for diameters smaller
than the exchange length of the given material. Here, the system behaves
effectively one-dimensional and the domain wall mobility agrees with a result
derived for a one-dimensional wall by Slonczewski. For low damping the domain
wall mobility decreases with decreasing damping constant. With increasing
diameter, a crossover to a vortex wall sets in which enhances the domain wall
mobility drastically. For a vortex wall the domain wall mobility is described
by the Walker-formula, with a domain wall width depending on the diameter of
the wire. The main difference is the dependence on damping: for a vortex wall
the domain wall mobility can be drastically increased for small values of the
damping constant up to a factor of .Comment: 5 pages, 6 figure
Caridoid crustaceans from the Ballagan Formation (Tournaisian, Lower Carboniferous) of Willie's Hole, Chirnside, Scottish Borders, UK
The descriptions of two co-occurring cardioid crustaceans from the Ballagan Formation (Tournaisian, Lower Carboniferous) of Chirnside, Scottish Borders, help to resolve the taxonomy of the genus Tealliocaris. Tealliocaris robusta Peach, 1908 is assigned to Schramocaris to form S. robusta (Peach, 1908) comb. nov. on the basis of morphological characters such as the rugosity and position of the branchial carinae as well as the nature of the pleon, and becomes the earliest representative of this genus in Scotland. A new species of Tealliocaris is also recognised from this locality and is described as T. briggsi sp. nov., based on the smooth carapace, lack of pleonic grooves and the number of spines on the scaphocerite and lateral margin of the anterior carapace. The systematic position of the Pendleian specimens identified by Peach (1908) as âTealliocaris robusta var.â is finally resolved and described as T. weegie sp. nov
Spin induced multipole moments for the gravitational wave flux from binary inspirals to third Post-Newtonian order
Using effective field theory techniques we calculate the source multipole
moments needed to obtain the spin contributions to the power radiated in
gravitational waves from inspiralling compact binaries to third Post-Newtonian
order (3PN). The multipoles depend linearly and quadratically on the spins and
include both spin(1)spin(2) and spin(1)spin(1) components. The results in this
paper provide the last missing ingredient required to determine the phase
evolution to 3PN including all spin effects which we will report in a separate
paper.Comment: 35 pages, 7 figures. Published versio
Spin induced multipole moments for the gravitational wave amplitude from binary inspirals to 2.5 Post-Newtonian order
Using the NRGR effective field theory formalism we calculate the remaining
source multipole moments necessary to obtain the spin contributions to the
gravitational wave amplitude to 2.5 Post-Newtonian (PN) order. We also
reproduce the tail contribution to the waveform linear in spin at 2.5PN arising
from the nonlinear interaction between the current quadrupole and the mass
monopole.Comment: 17 pages, 4 figures. v2 Minor changes, to appear in JCA
Polyacrylamide effects on infiltration in irrigated agriculture
Using polyacrylamide (PAM) following the NRCS conservation practice standard
increases infiltration in furrow irrigation. PAM at 10 g in-' (10 ppm) during water advance
nearly precludes detachment and transport of soil in furrows. If any sediment is entrained in the
flow, it is readily flocculated in the presence of PAM and settles to the furrow-bottom in loose pervious
structures. It was hypothesized that depositional surface seals that block pores are reduced or
made more permeable with PAM. On Portneuf silt beams (coarse-silty, mixed, superactive,
Durinodic Xeric Haplocalcid) furrow irrigation net infiltration increased 15%. Net increases on
finer textured soils were generally higher. Furrow streams containing more than 5 g L (5,000
ppm) sediment reduced infiltration and infiltration rate more than fivefold compared to streams
of clean water. Tension infiltrometry confirmed that PAM's maintenance of open pores to the furrow
surface provides the infiltration increase mechanism. Infiltration rates at 40 and 100 min
(1.6 and 3.9 inches) tension in PAM-treated furrows were double the rates of control furrows.
Recirculating infiltrometer data showed a 30% infiltration increase with PAM use and infiltration
was inversely related to maximum sediment concentration in the flow. Furrow inflow of
45 L min-1 (12 gal min-1 ) with PAM treatment decreased stream advance time 13% while reducing
sediment loss 76% compared to untreated 23 L min-1 (6 gal min-1) inflows. Use of
PAM in sprinkler irrigation streams reduced runoff 70% and sediment loss 75%, but tension infiltration
measurements were inconsistent, suggesting changes in surface-sealing effects with sprinkler
application of PAM are transient
Risk prediction models for head and neck cancer: a rapid review
Background:
Cancer risk assessment models are used to support prevention and early detection. However, few models have been developed for head and neck cancer (HNC).
Methods:
A rapid review of Embase and MEDLINE identified n = 3045 articles. Following dual screening, n = 14 studies were included. Quality appraisal using the PROBAST (risk of bias) instrument was conducted, and a narrative synthesis was performed to identify the best performing models in terms of risk factors and designs.
Results:
Six of the 14 models were assessed as âhighâ quality. Of these, three had high predictive performance achieving area under curve values over 0.8 (0.87â0.89). The common features of these models were their inclusion of predictors carefully tailored to the target population/anatomical subsite and development with external validation.
Conclusions:
Some existing models do possess the potential to identify and stratify those at risk of HNC but there is scope for improvement
Polyacrylamide (PAM) - A one million acre progress report
Water soluble polyacrylamide (PAM) was recognized in the early 1990s as an environmentally safe
and highly effective erosion-preventing and infiltration-enhancing chemical, when applied in very
dilute concentrations in furrow irrigation water (Lentz et al., 1992; Lentz and Sojka, 1994;
McCutchan et al., 1994; Trout et al., 1995; Sojka and Lentz, 1997; Sojka et al., 1998a,b). The mode
of action involves surface soil structure stabilization and maintenance of pore continuity. A
recommended conservation practice standard was published by NRCS in 1995 (Anonymous, 1995)
and is being revised in 1999. It delineates considerations and specifies methodology for. PAM-use.
Commercial sales of erosion-preventing PAMs began in 1995. Approximately one million acres
were treated in the United States in 1999. Extent of adoption of the practice outside the US is less
certain, but interest is growing in several countries and continents. Key aspects of this PAM
technology development are presented below
Limits on Production of Magnetic Monopoles Utilizing Samples from the DO and CDF Detectors at the Tevatron
We present 90% confidence level limits on magnetic monopole production at the
Fermilab Tevatron from three sets of samples obtained from the D0 and CDF
detectors each exposed to a proton-antiproton luminosity of
(experiment E-882). Limits are obtained for the production cross-sections and
masses for low-mass accelerator-produced pointlike Dirac monopoles trapped and
bound in material surrounding the D0 and CDF collision regions. In the absence
of a complete quantum field theory of magnetic charge, we estimate these limits
on the basis of a Drell-Yan model. These results (for magnetic charge values of
1, 2, 3, and 6 times the minimum Dirac charge) extend and improve previously
published bounds.Comment: 18 pages, 17 figures, REVTeX
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