2,979 research outputs found
Continuous sedation until death: The everyday moral reasoning of physicians, nurses and family caregivers in the UK, The Netherlands and Belgium
Copyright © 2014 Raus et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly credited.Background - Continuous sedation is increasingly used as a way to relieve symptoms at the end of life. Current research indicates that some physicians, nurses, and relatives involved in this practice experience emotional and/or moral distress. This study aims to provide insight into what may influence how professional and/or family carers cope with such distress.
Methods - This study is an international qualitative interview study involving interviews with physicians, nurses, and relatives of deceased patients in the UK, The Netherlands and Belgium (the UNBIASED study) about a case of continuous sedation at the end of life they were recently involved in. All interviews were transcribed verbatim and analysed by staying close to the data using open coding. Next, codes were combined into larger themes and categories of codes resulting in a four point scheme that captured all of the data. Finally, our findings were compared with others and explored in relation to theories in ethics and sociology.
Results - The participants’ responses can be captured as different dimensions of ‘closeness’, i.e. the degree to which one feels connected or ‘close’ to a certain decision or event. We distinguished four types of ‘closeness’, namely emotional, physical, decisional, and causal. Using these four dimensions of ‘closeness’ it became possible to describe how physicians, nurses, and relatives experience their involvement in cases of continuous sedation until death. More specifically, it shined a light on the everyday moral reasoning employed by care providers and relatives in the context of continuous sedation, and how this affected the emotional impact of being involved in sedation, as well as the perception of their own moral responsibility.
Conclusion - Findings from this study demonstrate that various factors are reported to influence the degree of closeness to continuous sedation (and thus the extent to which carers feel morally responsible), and that some of these factors help care providers and relatives to distinguish continuous sedation from euthanasia.The Economic and Social Research
Council (UK), the Research Foundation Flanders
(BE), the Flemish Cancer Association (BE), the Research Council of Ghent
University (BE), the Netherlands Organization for Scientific Research (NL) and
the Netherlands Organization for Health Research and Development (NL)
DNA Spools under Tension
DNA-spools, structures in which DNA is wrapped and helically coiled onto
itself or onto a protein core are ubiquitous in nature. We develop a general
theory describing the non-equilibrium behavior of DNA-spools under linear
tension. Two puzzling and seemingly unrelated recent experimental findings, the
sudden quantized unwrapping of nucleosomes and that of DNA toroidal condensates
under tension are theoretically explained and shown to be of the same origin.
The study provides new insights into nucleosome and chromatin fiber stability
and dynamics
In situ observations of waves in Venus’s polar lower thermosphere with Venus Express aerobraking
Waves are ubiquitous phenomena found in oceans and atmospheres alike. From the earliest formal studies of waves in the Earth’s atmosphere to more recent studies on other planets, waves have been shown to play a key role in shaping atmospheric bulk structure, dynamics and variability1, 2, 3, 4. Yet, waves are difficult to characterize as they ideally require in situ measurements of atmospheric properties that are difficult to obtain away from Earth. Thus, we have incomplete knowledge of atmospheric waves on planets other than our own, and we are thereby limited in our ability to understand and predict planetary atmospheres. Here we report the first ever in situ observations of atmospheric waves in Venus’s thermosphere (130–140 km) at high latitudes (71.5°–79.0°). These measurements were made by the Venus Express Atmospheric Drag Experiment (VExADE)5 during aerobraking from 24 June to 11 July 2014. As the spacecraft flew through Venus’s atmosphere, deceleration by atmospheric drag was sufficient to obtain from accelerometer readings a total of 18 vertical density profiles. We infer an average temperature of T = 114 ± 23 K and find horizontal wave-like density perturbations and mean temperatures being modulated at a quasi-5-day period
Dynamics of a Driven Single Flux Line in Superconductors
We study the low temperature dynamics of a single flux line in a bulk type-II
superconductor, driven by a surface current, both near and above the onset of
an instability which sets in at a critical driving. We found that above the
critical driving, the velocity profile of the flux line develops a
discontinuity.Comment: 10 pages with 4 figures, REVTE
Rhythmogenic neuronal networks, pacemakers, and k-cores
Neuronal networks are controlled by a combination of the dynamics of
individual neurons and the connectivity of the network that links them
together. We study a minimal model of the preBotzinger complex, a small
neuronal network that controls the breathing rhythm of mammals through periodic
firing bursts. We show that the properties of a such a randomly connected
network of identical excitatory neurons are fundamentally different from those
of uniformly connected neuronal networks as described by mean-field theory. We
show that (i) the connectivity properties of the networks determines the
location of emergent pacemakers that trigger the firing bursts and (ii) that
the collective desensitization that terminates the firing bursts is determined
again by the network connectivity, through k-core clusters of neurons.Comment: 4+ pages, 4 figures, submitted to Phys. Rev. Let
Model fluid in a porous medium: results for a Bethe lattice
We consider a lattice gas with quenched impurities or `quenched-annealed
binary mixture' on the Bethe lattice. The quenched part represents a porous
matrix in which the (annealed) lattice gas resides. This model features the 3
main factors of fluids in random porous media: wetting, randomness and
confinement. The recursive character of the Bethe lattice enables an exact
treatment, whose key ingredient is an integral equation yielding the
one-particle effective field distribution. Our analysis shows that this
distribution consists of two essentially different parts. The first one is a
continuous spectrum and corresponds to the macroscopic volume accessible to the
fluid, the second is discrete and comes from finite closed cavities in the
porous medium. Those closed cavities are in equilibrium with the bulk fluid
within the grand canonical ensemble we use, but are inaccessible in real
experimental situations. Fortunately, we are able to isolate their
contributions. Separation of the discrete spectrum facilitates also the
numerical solution of the main equation. The numerical calculations show that
the continuous spectrum becomes more and more rough as the temperature
decreases, and this limits the accuracy of the solution at low temperatures.Comment: 13 pages, 12 figure
Plasticity in current-driven vortex lattices
We present a theoretical analysis of recent experiments on current-driven
vortex dynamics in the Corbino disk geometry. This geometry introduces
controlled spatial gradients in the driving force and allows the study of the
onset of plasticity and tearing in clean vortex lattices. We describe plastic
slip in terms of the stress-driven unbinding of dislocation pairs, which in
turn contribute to the relaxation of the shear, yielding a nonlinear response.
The steady state density of free dislocations induced by the applied stress is
calculated as a function of the applied current and temperature. A criterion
for the onset of plasticity at a radial location in the disk yields a
temperature-dependent critical current that is in qualitative agreement with
experiments.Comment: 11 pages, 4 figure
Shear Alignment and Instability of Smectic Phases
We consider the shear flow of well-aligned one-component smectic phases, such
as thermotropic smectics and lamellar diblock copolymers, below the critical
region. We show that, as a result of thermal fluctuations of the layers,
parallel () alignment is generically unstable and perpendicular ()
alignment is stable against long-wavelength undulations. We also find,
surprisingly, that both and are stable for a narrow window of values
for the anisotropic viscosity.Comment: To appear in PRL. Revtex, 1 figure
- …