652 research outputs found
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Case Study: Using Cloudworks for an Open Literature Review
This case study is one of a series exploring the ongoing use and development of the Cloudworks site. This case study will focus on an expert elicitation Cloudscape established to support a literature review project led by the University of Exeter and funded by the Higher Education Academy (HEA): "The positioning of educational technologists in enhancing the student experience".
We will look in detail at the way the site was utilised by the project teams and other participants in the review, and evaluate the site's effectiveness in supporting this piece of research. We will make recommendations for the development of support resources associated with the site and suggest factors that might impact on the success of similar activities
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Using Cloudworks to Support OER Activities
This report forms the third and final output of the Pearls in the Clouds project, funded by the Higher Education Academy. It focuses on evaluation of the use of a social networking site, Cloudworks, to support evidence-based practice.
The aim of this project (Pearls in the Clouds) has been to evaluate the ways in which web 2.0 tools like Cloudworks can support evidence-informed practices in relation to learning and teaching. We have reviewed evidence from empirically grounded studies surrounding the uses of web2.0 in higher education and highlighted the gap between using web2.0 to support learning and teaching, and using it to support learning about learning and teaching (in an evidence-informed way) (Conole and Alevizou, 2010). We have reported on findings from a case study focusing on the use of Cloudworks by a community of practice - educational technologists - reflecting upon, and, negotiating their role in enhancing teaching and learning in higher education (Galley et al., 2010). The object of this study is to explore and evaluate the use of the site by individuals and communities involved in the production of, and research on, the development, delivery and use of Open Educational Resources (OER)
The measurement postulates of quantum mechanics are operationally redundant
Understanding the core content of quantum mechanics requires us to
disentangle the hidden logical relationships between the postulates of this
theory. Here we show that the mathematical structure of quantum measurements,
the formula for assigning outcome probabilities (Born's rule) and the
post-measurement state-update rule, can be deduced from the other quantum
postulates, often referred to as "unitary quantum mechanics", and the
assumption that ensembles on finite-dimensional Hilbert spaces are
characterised by finitely many parameters. This is achieved by taking an
operational approach to physical theories, and using the fact that the manner
in which a physical system is partitioned into subsystems is a subjective
choice of the observer, and hence should not affect the predictions of the
theory. In contrast to other approaches, our result does not assume that
measurements are related to operators or bases, it does not rely on the
universality of quantum mechanics, and it is independent of the interpretation
of probability.Comment: This is a post-peer-review, pre-copyedit version of an article
published in Nature Communications. The final authenticated version is
available online at: http://dx.doi.org/10.1038/s41467-019-09348-
Antioxidants that protect mitochondria reduce interleukin-6 and oxidative stress, improve mitochondrial function, and reduce biochemical markers of organ dysfunction in a rat model of acute sepsis
Funding This study was funded by the Medical Research Council (Grant number G0800149). Research material from this study is not available. Acknowledgement We are very grateful to Dr Robin A.J. Smith, Department of Chemistry, University of Otago, Dunedin, New Zealand, for the generous gifts of MitoE and MitoQ, without which this work would not have been possible.Peer reviewedPublisher PD
Response to "The measurement postulates of quantum mechanics are not redundant"
Adrian Kent has recently presented a critique [arXiv:2307.06191] of our paper
[Nat. Comms. 10, 1361 (2019)] in which he claims to refute our main result: the
measurement postulates of quantum mechanics can be derived from the rest of
postulates, once we assume that the set of mixed states of a finite-dimensional
Hilbert space is finite-dimensional. To construct his argument, Kent considers
theories resulting from supplementing quantum mechanics with hypothetical
"post-quantum" measurement devices. We prove that each of these theories
contains pure states (i.e. states of maximal knowledge) which are not rays of
the Hilbert space, in contradiction with the "pure state postulate" of quantum
mechanics. We also prove that these alternatives violate the
finite-dimensionality of mixed states. Each of these two facts separately
invalidates the refutation. In this note we also clarify the assumptions used
in the above-cited paper and discuss the notions of pure state, physical
system, and the sensitivity of the structure of the state space under
modifications of the measurements or the dynamics.Comment: 7 page
A Numerical Relativity Waveform Surrogate Model for Generically Precessing Binary Black Hole Mergers
A generic, non-eccentric binary black hole (BBH) system emits gravitational
waves (GWs) that are completely described by 7 intrinsic parameters: the black
hole spin vectors and the ratio of their masses. Simulating a BBH coalescence
by solving Einstein's equations numerically is computationally expensive,
requiring days to months of computing resources for a single set of parameter
values. Since theoretical predictions of the GWs are often needed for many
different source parameters, a fast and accurate model is essential. We present
the first surrogate model for GWs from the coalescence of BBHs including all
dimensions of the intrinsic non-eccentric parameter space. The surrogate
model, which we call NRSur7dq2, is built from the results of numerical
relativity simulations. NRSur7dq2 covers spin magnitudes up to and mass
ratios up to , includes all modes, begins about orbits
before merger, and can be evaluated in . We find the
largest NRSur7dq2 errors to be comparable to the largest errors in the
numerical relativity simulations, and more than an order of magnitude smaller
than the errors of other waveform models. Our model, and more broadly the
methods developed here, will enable studies that would otherwise require
millions of numerical relativity waveforms, such as parameter inference and
tests of general relativity with GW observations.Comment: 10 pages, 5 figures; Added report numbe
Effects of early and late diabetic neuropathy on sciatic nerve block duration and neurotoxicity in Zucker diabetic fatty rats
Background The neuropathy of type II diabetes mellitus (DM) is increasing in prevalence worldwide. We aimed to test the hypothesis that in a rodent model of type II DM, neuropathy would lead to increased neurotoxicity and block duration after lidocaine-induced sciatic nerve block when compared with control animals. Methods Experiments were carried out in Zucker diabetic fatty rats aged 10 weeks (early diabetic) or 18 weeks (late diabetic, with or without insulin 3 units per day), and age-matched healthy controls. Left sciatic nerve block was performed using 0.2 ml lidocaine 2%. Nerve conduction velocity (NCV) and F-wave latency were used to quantify nerve function before, and 1 week after nerve block, after which sciatic nerves were used for neurohistopathology. Results Early diabetic animals did not show increased signs of nerve dysfunction after nerve block. In late diabetic animals without insulin vs control animals, NCV was 34.8 (5.0) vs 41.1 (4.1) ms s−1 (P<0.01), and F-wave latency was 7.7 (0.5) vs 7.0 (0.2) ms (P<0.01), respectively. Motor nerve block duration was prolonged in late diabetic animals, but neurotoxicity was not. Late diabetic animals receiving insulin showed intermediate results. Conclusions In a rodent type II DM model, nerves have increased sensitivity for short-acting local anaesthetics without adjuvants in vivo, as evidenced by prolonged block duration. This sensitivity appears to increase with the progression of neuropathy. Our results do not support the hypothesis that neuropathy due to type II DM increases the risk of nerve injury after nerve bloc
Finite size corrections to the radiation reaction force in classical electrodynamics
We introduce an effective field theory approach that describes the motion of
finite size objects under the influence of electromagnetic fields. We prove
that leading order effects due to the finite radius of a spherically
symmetric charge is order rather than order in any physical model, as
widely claimed in the literature. This scaling arises as a consequence of
Poincar\'e and gauge symmetries, which can be shown to exclude linear
corrections. We use the formalism to calculate the leading order finite size
correction to the Abraham-Lorentz-Dirac force.Comment: 4 pages, 2 figure
Bench-to-bedside review : targeting antioxidants to mitochondria in sepsis
Peer reviewedPublisher PD
Quantum Relativity of Subsystems
One of the most basic notions in physics is the partitioning of a system into
subsystems, and the study of correlations among its parts. In this work, we
explore these notions in the context of quantum reference frame (QRF)
covariance, in which this partitioning is subject to a symmetry constraint. We
demonstrate that different reference frame perspectives induce different sets
of subsystem observable algebras, which leads to a gauge-invariant,
frame-dependent notion of subsystems and entanglement. We further demonstrate
that subalgebras which commute before imposing the symmetry constraint can
translate into non-commuting algebras in a given QRF perspective after symmetry
imposition. Such a QRF perspective does not inherit the distinction between
subsystems in terms of the corresponding tensor factorizability of the
kinematical Hilbert space and observable algebra. Since the condition for this
to occur is contingent on the choice of QRF, the notion of subsystem locality
is frame-dependent.Comment: 8+9 pages, 1 figur
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