444 research outputs found
Should I stay or should I go? Patient understandings of and responses to source-isolation practices
Isolation of patients, who are colonised or infected with a multidrug-resistant organism (source-isolation), is a common practice in most acute health-care settings, to prevent transmission to other patients. Efforts to improve the efficacy of source-isolation in hospitals focus on healthcare staff compliance with isolation precautions. In this article we examine patients’ awareness, understandings and observance of source-isolation practices and directives with a view to understanding better the roles patients play or could play in transmitting, or limiting transmission, of multidrug-resistant organisms (MRO). Seventeen source-isolated adult surgical patients and two relatives participated in video-reflexive ethnography and interviews. We learned that, although most of these patients wanted to protect themselves and others from colonisation/infection with a MRO, they had a limited understanding of what precautions they could take while in isolation and found it difficult to obtain ongoing information. Thus, many patients regularly left their source-isolation rooms without taking appropriate precautions and were potentially contributing to environmental contamination and transmission. Some patients also interacted with other patients and their personal belongings in ways that exposed other patients, unnecessarily, to colonisation/infection risk. By not providing patients with adequate information on infection risk or how they could contribute to their own safety or that of others, they are denied the opportunity to fully engage in their healthcare. To improve the efficacy of source-isolation and contact precautions in general, patient care providers should consider colonised or infected patients as active partners in reducing transmission and involve patients and relatives in regular, ongoing conversations about transmission prevention
Two-photon final states in peripheral heavy ion collisions
We discuss processes leading to two photon final states in peripheral heavy
ion collisions at RHIC. Due to the large photon luminosity we show that the
continuum subprocess can be observed with a
large number of events. We study this reaction when it is intermediated by a
resonance made of quarks or gluons and discuss its interplay with the continuum
process, verifying that in several cases the resonant process ovewhelms the
continuum one. It is also investigated the possibility of observing a scalar
resonance (the meson) in this process. Assuming for the the
mass and total decay width values recently reported by the E791 Collaboration
we show that RHIC may detect this particle in its two photon decay mode if its
partial photonic decay width is of the order of the ones discussed in the
literature.Comment: 10 pages, 8 figure
Soft Photons in Hadron-Hadron Collisions: Synchrotron Radiation from the QCD Vacuum?
We discuss the production of soft photons in high energy hadron-hadron
collisions. We present a model where quarks and antiquarks in the hadrons emit
``synchrotron light'' when being deflected by the chromomagnetic fields of the
QCD vacuum, which we assume to have a nonperturbative structure. This gives a
source of prompt soft photons with frequencies in the c.m.
system of the collision in addition to hadronic bremsstrahlung. In comparing
the frequency spectrum and rate of ``synchrotron'' photons to experimental
results we find some supporting evidence for their existence. We make an
exclusive--inclusive connection argument to deduce from the ``synchrotron''
effect a behaviour of the neutron electric formfactor proportional
to for . We find this to be consistent with
available data. In our view, soft photon production in high energy
hadron-hadron and lepton-hadron collisions as well as the behaviour of
electromagnetic hadron formfactors for low are thus sensitive probes of
the nonperturbative structure of the QCD vacuum.Comment: Heidelberg preprint HD-THEP-94-36, 31 pages, LaTeX + ZJCITE.sty
(included), 12 figures appended as uuencoded compressed ps-fil
A renormalisation group approach to two-body scattering in the presence of long-range forces
We apply renormalisation-group methods to two-body scattering by a
combination of known long-range and unknown short-range potentials. We impose a
cut-off in the basis of distorted waves of the long-range potential and
identify possible fixed points of the short-range potential as this cut-off is
lowered to zero. The expansions around these fixed points define the power
countings for the corresponding effective field theories. Expansions around
nontrivial fixed points are shown to correspond to distorted-wave versions of
the effective-range expansion. These methods are applied to scattering in the
presence of Coulomb, Yukawa and repulsive inverse-square potentials.Comment: 22 pages (RevTeX), 4 figure
Electromagnetic Casimir densities for a wedge with a coaxial cylindrical shell
Vacuum expectation values of the field square and the energy-momentum tensor
for the electromagnetic field are investigated for the geometry of a wedge with
a coaxal cylindrical boundary. All boundaries are assumed to be perfectly
conducting and both regions inside and outside the shell are considered. By
using the generalized Abel-Plana formula, the vacuum expectation values are
presented in the form of the sum of two terms. The first one corresponds to the
geometry of the wedge without the cylindrical shell and the second term is
induced by the presence of the shell. The vacuum energy density induced by the
shell is negative for the interior region and is positive for the exterior
region. The asymptotic behavior of the vacuum expectation values are
investigated in various limiting cases. It is shown that the vacuum forces
acting on the wedge sides due to the presence of the cylindrical boundary are
always attractive.Comment: 21 pages, 7 figure
Inertial and fluctuational effects on the motion of a Bose superfluid vortex
We study the motion of a vortex under the influence of a harmonic force in an
approximately two dimensional trapped Bose-condensed gas. The
Hall-Vinen-Iordanskii equations, modified to include a fluctuational force and
an inertial mass term, are solved for the vortex motion. The mass of the vortex
has a strong influence on the time it takes the vortex to escape the trap.
Since the vortex mass also depends on the trap size we have an additional
dependence on the trap size in the escape time which we compare to the massless
case.Comment: Submitted to J. Low. Temp. Phy
High Precision Mass Measurements in and Families Revisited
High precision mass measurements in and families performed
in 1980-1984 at the VEPP-4 collider with OLYA and MD-1 detectors are revisited.
The corrections for the new value of the electron mass are presented. The
effect of the updated radiative corrections has been calculated for the
and mass measurements.Comment: 5 pages, 1 table, submitted to Phys. Lett.
Parton energy loss at strong coupling and the universal bound
The apparent universality of jet quenching observed in heavy ion collisions
at RHIC for light and heavy quarks, as well as for quarks and gluons, is very
puzzling and calls for a theoretical explanation. Recently it has been proposed
that the synchrotron--like radiation at strong coupling gives rise to a
universal bound on the energy of a parton escaping from the medium. Since this
bound appears quite low, almost all of the observed particles at high
transverse momentum have to originate from the surface of the hot fireball.
Here I make a first attempt of checking this scenario against the RHIC data and
formulate a "Universal Bound Model" of jet quenching that can be further tested
at RHIC and LHC.Comment: 8 pages, 2 figures, invited plenary talk given at "Hard Probes 2008"
Conference, 8-14 June 2008, Illa da Toxa, Galicia, Spai
Measurement of the refractive index and attenuation length of liquid xenon for its scintillation light
The attenuation length and refractive index of liquid xenon for intrinsic
scintillation light (178nm) have been measured in a single experiment. The
value obtained for attenuation length is 364 +- 18 mm. The refractive index is
found to be 1.69 +- 0.02. Both values were measured at a temperature of 170 +-
1 K.Comment: 28 pages, 9 figures, accepted for publication in NIM
Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events
The - oscillation frequency has been measured with a sample of
23 million \B\bar B pairs collected with the BABAR detector at the PEP-II
asymmetric B Factory at SLAC. In this sample, we select events in which both B
mesons decay semileptonically and use the charge of the leptons to identify the
flavor of each B meson. A simultaneous fit to the decay time difference
distributions for opposite- and same-sign dilepton events gives ps.Comment: 7 pages, 1 figure, submitted to Physical Review Letter
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