2,456 research outputs found
What is the contribution of physician associates in hospital care in England? A mixed methods, multiple case study.
OBJECTIVES: To investigate the deployment of physician associates (PAs); the factors supporting and inhibiting their employment and their contribution and impact on patients' experience and outcomes and the organisation of services. DESIGN: Mixed methods within a case study design, using interviews, observations, work diaries and documentary analysis. SETTING: Six acute care hospitals in three regions of England in 2016-2017. PARTICIPANTS: 43 PAs, 77 other health professionals, 28 managers, 28 patients and relatives. RESULTS: A key influencing factor supporting the employment of PAs in all settings was a shortage of doctors. PAs were found to be acceptable, appropriate and safe members of the medical/surgical teams by the majority of doctors, managers and nurses. They were mainly deployed to undertake inpatient ward work in the medical/surgical team during core weekday hours. They were reported to positively contribute to: continuity within their medical/surgical team, patient experience and flow, inducting new junior doctors, supporting the medical/surgical teams' workload, which released doctors for more complex patients and their training. The lack of regulation and attendant lack of authority to prescribe was seen as a problem in many but not all specialties. The contribution of PAs to productivity and patient outcomes was not quantifiable separately from other members of the team and wider service organisation. Patients and relatives described PAs positively but most did not understand who and what a PA was, often mistaking them for doctors. CONCLUSIONS: This study offers new insights concerning the deployment and contribution of PAs in medical and surgical specialties in English hospitals. PAs provided a flexible addition to the secondary care workforce without drawing from existing professions. Their utility in the hospital setting is unlikely to be completely realised without the appropriate level of regulation and authority to prescribe medicines and order ionising radiation within their scope of practice
The Behavior of Granular Materials under Cyclic Shear
The design and development of a parallel plate shear cell for the study of
large scale shear flows in granular materials is presented. The parallel plate
geometry allows for shear studies without the effects of curvature found in the
more common Couette experiments. A system of independently movable slats
creates a well with side walls that deform in response to the motions of grains
within the pack. This allows for true parallel plate shear with minimal
interference from the containing geometry. The motions of the side walls also
allow for a direct measurement of the velocity profile across the granular
pack. Results are presented for applying this system to the study of transients
in granular shear and for shear-induced crystallization. Initial shear profiles
are found to vary from packing to packing, ranging from a linear profile across
the entire system to an exponential decay with a width of approximately 6 bead
diameters. As the system is sheared, the velocity profile becomes much sharper,
resembling an exponential decay with a width of roughly 3 bead diameters.
Further shearing produces velocity profiles which can no longer be fit to an
exponential decay, but are better represented as a Gaussian decay or error
function profile. Cyclic shear is found to produce large scale ordering of the
granular pack, which has a profound impact on the shear profile. There exist
periods of time in which there is slipping between layers as well as periods of
time in which the layered particles lock together resulting in very little
relative motion.Comment: 10 pages including 12 figure
Randomised feasibility trial into the effects of low-frequency electrical muscle stimulation in advanced heart failure patients.
OBJECTIVES: Low-frequency electrical muscle stimulation (LF-EMS) may have the potential to reduce breathlessness and increase exercise capacity in the chronic heart failure population who struggle to adhere to conventional exercise. The study's aim was to establish if a randomised controlled trial of LF-EMS was feasible. DESIGN AND SETTING: Double blind (participants, outcome assessors), randomised study in a secondary care outpatient cardiac rehabilitation programme. PARTICIPANTS: Patients with severe heart failure (New York Heart Association class III-IV) having left ventricular ejection fraction <40% documented by echocardiography were eligible. INTERVENTIONS: Participants were randomised (remotely by computer) to 8 weeks (5Ă60 mins per week) of either LF-EMS intervention (4âHz, continuous, n=30) or sham placebo (skin level stimulation only, n=30) of the quadriceps and hamstrings muscles. Participants used the LF-EMS straps at home and were supervised weekly OUTCOME MEASURES: Recruitment, adherence and tolerability to the intervention were measured during the trial as well as physiological outcomes (primary outcome: 6âmin walk, secondary outcomes: quadriceps strength, quality of life and physical activity). RESULTS: Sixty of 171 eligible participants (35.08%) were recruited to the trial. 12 (20%) of the 60 patients (4 LF-EMS and 8 sham) withdrew. Forty-one patients (68.3%), adhered to the protocol for at least 70% of the sessions. The physiological measures indicated no significant differences between groups in 6âmin walk distance(p=0.13) and quality of life (p=0.55) although both outcomes improved more with LF-EMS. CONCLUSION: Patients with severe heart failure can be recruited to and tolerate LF-EMS studies. A larger randomised controlled trial (RCT) in the advanced heart failure population is technically feasible, although adherence to follow-up would be challenging. The preliminary improvements in exercise capacity and quality of life were minimal and this should be considered if planning a larger trial. TRIAL REGISTRATION NUMBER: ISRCTN16749049
Freshly Formed Dust in the Cassiopeia A Supernova Remnant as Revealed by the Spitzer Space Telescope
We performed Spitzer Infrared Spectrograph mapping observations covering
nearly the entire extent of the Cassiopeia A supernova remnant (SNR), producing
mid-infrared (5.5-35 micron) spectra every 5-10". Gas lines of Ar, Ne, O, Si, S
and Fe, and dust continua were strong for most positions. We identify three
distinct ejecta dust populations based on their continuum shapes. The dominant
dust continuum shape exhibits a strong peak at 21 micron. A line-free map of 21
micron-peak dust made from the 19-23 micron range closely resembles the [Ar
II], [O IV], and [Ne II] ejecta-line maps implying that dust is freshly formed
in the ejecta. Spectral fitting implies the presence of SiO2, Mg
protosilicates, and FeO grains in these regions. The second dust type exhibits
a rising continuum up to 21 micron and then flattens thereafter. This ``weak 21
micron'' dust is likely composed of Al2O3 and C grains. The third dust
continuum shape is featureless with a gently rising spectrum and is likely
composed of MgSiO3 and either Al2O3 or Fe grains. Using the least massive
composition for each of the three dust classes yields a total mass of 0.02
Msun. Using the most-massive composition yields a total mass of 0.054 Msun. The
primary uncertainty in the total dust mass stems from the selection of the dust
composition necessary for fitting the featureless dust as well as 70 micron
flux. The freshly formed dust mass derived from Cas A is sufficient from SNe to
explain the lower limit on the dust masses in high redshift galaxies.Comment: 8 figures: Accepted for the publication in Ap
Parametrization of the octupole degrees of freedom
A simple parametrization for the octupole collective variables is proposed
and the symmetries of the wave functions are discussed in terms of the
solutions corresponding to the vibrational limit. [PACS: 21.60Ev, 21.60.Fw,
21.10.Re]Comment: 14 page
The impact of marketisation on postgraduate career preparedness in a high skills economy
This study focuses on the consequences for high skills development of the erosion of the once clear demarcation between higher education and business. It contributes to the broader debate about the relevance of higher education for thewell-being of the society of the future. The research explores the effects of marketisation on the postgraduate curriculum and studentsâ preparedness for careers in public relations and marketing communications. Interviews with lecturers and students in two universities in the UK and Australia indicate that a tension exists between academic rigour and corporate relevancy. The consequences are a diminution of academic attachment to critique and wider social/cultural engagement, with a resulting impoverishment of studentsâ creative abilities and critical consciences. Subsequently, graduates of public relations and marketing communications, and to some extent those from other profession-related disciplines, are insufficiently prepared for careers as knowledge workers in a future high-skills economy
Near-infrared Observations of Nova V574 Puppis (2004)
We present results obtained from extensive near-infrared spectroscopic and
photometric observations of nova V574 Pup during its 2004 outburst. The
observations were obtained over four months, starting from 2004 November 25
(four days after the nova outburst) to 2005 March 20. The near-IR JHK light
curve is presented - no evidence is seen from it for dust formation to have
occurred during our observations. In the early decline phase, the JHK spectra
of the nova are dominated by emission lines of hydrogen Brackett and Paschen
series, OI, CI and HeI. We also detect the fairly uncommon Fe II line at 1.6872
micron in the early part of our observations. The strengths of the HeI lines at
1.0830 micron and 2.0585 micron are found to become very strong towards the end
of the observations indicating a progression towards higher excitation
conditions in the nova ejecta. The width of the emission lines do not show any
significant change during the course of our observations. The slope of the
continuum spectrum was found to have a lambda^{-2.75} dependence in the early
stages which gradually becomes flatter with time and changes to a free-free
spectral dependence towards the later stages. Recombination analysis of the HI
lines shows deviations from Case B conditions during the initial stages.
However, towards the end of our observations, the line strengths are well
simulated with case B model values with electron density n_e = 10^{9-10}
cm^{-3} and a temperature equal to 10^4 K. Based on our distance estimate to
the nova of 5.5 kpc and the observed free-free continuum emission in the later
part of the observations, we estimate the ionized mass of the ejecta to be
between 10^{-5} and 10^{-6} solar-mass.Comment: 10 pages, 8 figures, Accepted for publication in MNRA
Density Fluctuations in an Electrolyte from Generalized Debye-Hueckel Theory
Near-critical thermodynamics in the hard-sphere (1,1) electrolyte is well
described, at a classical level, by Debye-Hueckel (DH) theory with (+,-) ion
pairing and dipolar-pair-ionic-fluid coupling. But DH-based theories do not
address density fluctuations. Here density correlations are obtained by
functional differentiation of DH theory generalized to {\it non}-uniform
densities of various species. The correlation length diverges universally
at low density as (correcting GMSA theory). When
one has as
where the amplitudes compare informatively with experimental data.Comment: 5 pages, REVTeX, 1 ps figure included with epsf. Minor changes,
references added. Accepted for publication in Phys. Rev. Let
Dragging a polymer chain into a nanotube and subsequent release
We present a scaling theory and Monte Carlo (MC) simulation results for a
flexible polymer chain slowly dragged by one end into a nanotube. We also
describe the situation when the completely confined chain is released and
gradually leaves the tube. MC simulations were performed for a self-avoiding
lattice model with a biased chain growth algorithm, the pruned-enriched
Rosenbluth method. The nanotube is a long channel opened at one end and its
diameter is much smaller than the size of the polymer coil in solution. We
analyze the following characteristics as functions of the chain end position
inside the tube: the free energy of confinement, the average end-to-end
distance, the average number of imprisoned monomers, and the average stretching
of the confined part of the chain for various values of and for the number
of monomers in the chain, . We show that when the chain end is dragged by a
certain critical distance into the tube, the polymer undergoes a
first-order phase transition whereby the remaining free tail is abruptly sucked
into the tube. This is accompanied by jumps in the average size, the number of
imprisoned segments, and in the average stretching parameter. The critical
distance scales as . The transition takes place when
approximately 3/4 of the chain units are dragged into the tube. The theory
presented is based on constructing the Landau free energy as a function of an
order parameter that provides a complete description of equilibrium and
metastable states. We argue that if the trapped chain is released with all
monomers allowed to fluctuate, the reverse process in which the chain leaves
the confinement occurs smoothly without any jumps. Finally, we apply the theory
to estimate the lifetime of confined DNA in metastable states in nanotubes.Comment: 13pages, 14figure
Dirac R-matrix calculations for the electron-impact excitation of neutral tungsten providing noninvasive diagnostics for magnetic confinement fusion
Neutral tungsten is the primary candidate as a wall material in the divertor
region of the International Thermonuclear Experimental Reactor (ITER). The
efficient operation of ITER depends heavily on precise atomic physics
calculations for the determination of reliable erosion diagnostics, helping to
characterise the influx of tungsten impurities into the core plasma. The
following paper presents detailed calculations of the atomic structure of
neutral tungsten using the multiconfigurational Dirac-Fock method, drawing
comparisons with experimental measurements where available, and includes a
critical assessment of existing atomic structure data. We investigate the
electron-impact excitation of neutral tungsten using the Dirac R-matrix method
and, by employing collisional-radiative models, we benchmark our results with
recent Compact Toroidal Hybrid measurements. The resulting comparisons
highlight alternative diagnostic lines to the widely used 400.88nm line.Comment: 10 pages, 6 figure
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