11,620 research outputs found
Casimir invariants and characteristic identities for
A full set of (higher order) Casimir invariants for the Lie algebra
is constructed and shown to be well defined in the category
generated by the highest weight (unitarizable) irreducible
representations with only a finite number of non-zero weight components.
Moreover the eigenvalues of these Casimir invariants are determined explicitly
in terms of the highest weight. Characteristic identities satisfied by certain
(infinite) matrices with entries from are also determined and
generalize those previously obtained for by Bracken and Green.Comment: 10 pages, PlainTe
R-matrices and Tensor Product Graph Method
A systematic method for constructing trigonometric R-matrices corresponding
to the (multiplicity-free) tensor product of any two affinizable
representations of a quantum algebra or superalgebra has been developed by the
Brisbane group and its collaborators. This method has been referred to as the
Tensor Product Graph Method. Here we describe applications of this method to
untwisted and twisted quantum affine superalgebras.Comment: LaTex 7 pages. Contribution to the APCTP-Nankai Joint Symposium on
"Lattice Statistics and Mathematical Physics", 8-10 October 2001, Tianjin,
Chin
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Interventions to improve hand hygiene compliance in patient care
Background
Health careâassociated infection is a major cause of morbidity and mortality. Hand hygiene is regarded as an effective preventive measure. This is an update of a previously published review.
Objectives
To assess the shortâ and longâterm success of strategies to improve compliance to recommendations for hand hygiene, and to determine whether an increase in hand hygiene compliance can reduce rates of health careâassociated infection.
Search methods
We conducted electronic searches of the Cochrane Register of Controlled Trials, PubMed, Embase, and CINAHL. We conducted the searches from November 2009 to October 2016.
Selection criteria
We included randomised trials, nonârandomised trials, controlled beforeâafter studies, and interrupted time series analyses (ITS) that evaluated any intervention to improve compliance with hand hygiene using soap and water or alcoholâbased hand rub (ABHR), or both.
Data collection and analysis
Two review authors independently screened citations for inclusion, extracted data, and assessed risks of bias for each included study. Metaâanalysis was not possible, as there was substantial heterogeneity across studies. We assessed the certainty of evidence using the GRADE approach and present the results narratively in a 'Summary of findings' table.
Main results
This review includes 26 studies: 14 randomised trials, two nonârandomised trials and 10 ITS studies. Most studies were conducted in hospitals or longâterm care facilities in different countries, and collected data from a variety of healthcare workers. Fourteen studies assessed the success of different combinations of strategies recommended by the World Health Organization (WHO) to improve hand hygiene compliance. Strategies consisted of the following: increasing the availability of ABHR, different types of education for staff, reminders (written and verbal), different types of performance feedback, administrative support, and staff involvement. Six studies assessed different types of performance feedback, two studies evaluated education, three studies evaluated cues such as signs or scent, and one study assessed placement of ABHR. Observed hand hygiene compliance was measured in all but three studies which reported product usage. Eight studies also reported either infection or colonisation rates. All studies had two or more sources of high or unclear risks of bias, most often associated with blinding or independence of the intervention.
Multimodal interventions that include some but not all strategies recommended in the WHO guidelines may slightly improve hand hygiene compliance (five studies; 56 centres) and may slightly reduce infection rates (three studies; 34 centres), low certainty of evidence for both outcomes.
Multimodal interventions that include all strategies recommended in the WHO guidelines may slightly reduce colonisation rates (one study; 167 centres; low certainty of evidence). It is unclear whether the intervention improves hand hygiene compliance (five studies; 184 centres) or reduces infection (two studies; 16 centres) because the certainty of this evidence is very low.
Multimodal interventions that contain all strategies recommended in the WHO guidelines plus additional strategies may slightly improve hand hygiene compliance (six studies; 15 centres; low certainty of evidence). It is unclear whether this intervention reduces infection rates (one study; one centre; very low certainty of evidence).
Performance feedback may improve hand hygiene compliance (six studies; 21 centres; low certainty of evidence). This intervention probably slightly reduces infection (one study; one centre) and colonisation rates (one study; one centre) based on moderate certainty of evidence.
Education may improve hand hygiene compliance (two studies; two centres), low certainty of evidence.
Cues such as signs or scent may slightly improve hand hygiene compliance (three studies; three centres), low certainty of evidence.
Placement of ABHR close to point of use probably slightly improves hand hygiene compliance (one study; one centre), moderate certainty of evidence.
Authors' conclusions
With the identified variability in certainty of evidence, interventions, and methods, there remains an urgent need to undertake methodologically robust research to explore the effectiveness of multimodal versus simpler interventions to increase hand hygiene compliance, and to identify which components of multimodal interventions or combinations of strategies are most effective in a particular context
Eigenvalues of Casimir operators for
A full set of Casimir operators for the Lie superalgebra is
constructed and shown to be well defined in the category generated by
the highest weight irreducible representations with only a finite number of
non-zero weight components. The eigenvalues of these Casimir operators are
determined explicitly in terms of the highest weight. Characteristic identities
satisfied by certain (infinite) matrices with entries from are
also determined.Comment: 10 pages, Te
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Knowing too much: knowledge of energy content prevents liking change through flavour-nutrient associations
Associations between flavours and the consequences of ingestion can lead to changes in flavour liking depending on nutrient content, an example of flavour-nutrient learning. Expectations about the consequences of ingestion can be modified by information at the point of ingestion, such as nutritional labelling. What is unknown is the extent to which these label-based expectations modify flavour-nutrient learning. Since nutrient information can alter expectations about how filling a product would be, we hypothesised that labels predicting higher energy (HE) content would enhance satiety and so promote more rapid flavour learning. To test this, participants consumed either a lower (LE: 164kcal) or HE (330kcal) yoghurt breakfast on four separate days, either with no product label or with labels displaying either the actual energy content (Congruent label) or inaccurate energy (Incongruent label). Participants rated liking on all four days: on days one and four they could also consume as much as they liked, but consumed a fixed amount (300g) on days two and three. Both liking and intake increased with exposure in the HE, and decreased in the LE, condition when unlabelled in line with flavour-nutrient learning. In contrast, no significant changes were seen in either the Congruent or Incongruent label conditions. Contrary to predictions, these data suggest that flavour-nutrient learning occurs when there is an absence of explicit expectations of actual nutrient content, with both accurate and inaccurate information on nutrient content disrupting learning
Detection of Coronal Mass Ejections in V471 Tauri with the Hubble Space Telescope
V471 Tauri, an eclipsing system consisting of a hot DA white dwarf (WD) and a
dK2 companion in a 12.5-hour orbit, is the prototype of the pre-cataclysmic
binaries. The late-type component is magnetically active, due to its being
constrained to rotate synchronously with the short orbital period. During a
program of UV spectroscopy of V471 Tau, carried out with the Goddard High
Resolution Spectrograph (GHRS) onboard the Hubble Space Telescope, we
serendipitously detected two episodes in which transient absorptions in the Si
III 1206 A resonance line appeared suddenly, on a timescale of <2 min. The
observations were taken in a narrow spectral region around Ly-alpha, and were
all obtained near the two quadratures of the binary orbit, i.e., at maximum
projected separation (~3.3 Rsun) of the WD and K star.
We suggest that these transient features arise when coronal mass ejections
(CME's) from the K2 dwarf pass across the line of sight to the WD. Estimates of
the velocities, densities, and masses of the events in V471 Tau are generally
consistent with the properties of solar CME's. Given our detection of 2 events
during 6.8 hr of GHRS observing, along with a consideration of the restricted
range of latitudes and longitudes on the K star's surface that can give rise to
trajectories passing in front of the WD as seen from Earth, we estimate that
the active V471 Tau dK star emits some 100-500 CME's per day, as compared to
1-3 per day for the Sun. The K dwarf's mass-loss rate associated with CME's is
at least (5-25) x 10^{-14} Msun/yr, but it may well be orders of magnitude
higher if most of the silicon is in ionization states other than Si III.Comment: 24 pages AASTeX, 4 figures. Accepted by Astrophysical Journa
Stellar Contribution to the Galactic Bulge Microlensing Optical Depth
We estimate the optical depth to self-lensing by stars in the Galactic bulge
using the HST star counts of Holtzman et al and Zoccali et al as extrapolated
by Gould into the brown-dwarf and remnant regimes and deprojected along the
line of sight using the model of Dwek et al. We find a self-lensing optical
depth tau(bulge-bulge)=0.98 x 10^{-6}. When combined with the lensing of bulge
stars by foreground stars in the disk, this yields tau(bulge-total)=1.63 x
10^{-6}, in reasonable agreement with the estimates of tau=2.13 +/- 0.40 x
10^{-6} and tau=1.08 +/- 0.30 x 10^{-6} based on observations of clump giants
by the MACHO and EROS collaborations.Comment: 10 pages, including 1 figure. Submitted to Ap
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