8,942 research outputs found
Recommended from our members
Methods of Studying False Memory
The study of memory is one of those domains in psychology which has clear practical relevance. Think, for example, about people with Alzheimer’s disease. Devastating dysfunction experienced by these patients makes it abundantly evident that our memory constitutes an overarching and critical role in our daily life. However, in the study of memory, there is another memory phenomenon that also carries with it enormous theoretical and practical implications, namely, memory illusions. That is, people frequently claim that they remember details or even an entire event that never actually happened. These false memories can have serious consequences when they appear in the testimony of witness, victims, or suspects in legal cases (Howe & Knott, 2015; Otgaar, De Ruiter, Howe, Hoetmer, & van Reekum, in press). A person, for example, might falsely remember that he/she was sexually abused when he/she was a child, and this memory illusion might lead to false accusations that may result in wrongful convictions
L-branes
The superembedding approach to -branes is used to study a class of
-branes which have linear multiplets on the worldvolume. We refer to these
branes as L-branes. Although linear multiplets are related to scalar multiplets
(with 4 or 8 supersymmetries) by dualising one of the scalars of the latter to
a -form field strength, in many geometrical situations it is the linear
multiplet version which arises naturally. Furthermore, in the case of 8
supersymmetries, the linear multiplet is off-shell in contrast to the scalar
multiplet. The dynamics of the L-branes are obtained by using a systematic
procedure for constructing the Green-Schwarz action from the superembedding
formalism. This action has a Dirac-Born-Infeld type structure for the -form.
In addition, a set of equations of motion is postulated directly in superspace,
and is shown to agree with the Green-Schwarz equations of motion.Comment: revised version, minor changes, references added, 22 pages, no
figures, LaTe
Identifying the challenges and facilitators of implementing a COPD care bundle.
BACKGROUND: Care bundles have been shown to improve outcomes, reduce hospital readmissions and reduce length of hospital stay; therefore increasing the speed of uptake and delivery of care bundles should be a priority in order to deliver more timely improvements and consistent high-quality care. Previous studies have detailed the difficulties of obtaining full compliance to bundle elements but few have described the underlying reasons for this. In order to improve future implementation this paper investigates the challenges encountered by clinical teams implementing a chronic obstructive pulmonary disease (COPD) care bundle and describes actions taken to overcome these challenges. METHODS: An initial retrospective documentary analysis of data from seven clinical implementation teams was undertaken to review the challenges faced by the clinical teams. Three focus groups with healthcare professionals and managers explored solutions to these challenges developed during the project. RESULTS: Documentary analysis identified 28 challenges which directly impacted implementation of the COPD care bundle within five themes; staffing, infrastructure, process, use of improvement methodology and patient and public involvement. Focus groups revealed that the five most significant challenges for all groups were: staff too busy, staff shortages, lack of staff engagement, added workload of the bundle and patient coding issues. The participants shared facilitating factors used to overcome issues including: shifting perceptions to improve engagement, further education sessions to increase staff participation and gaining buy-in from managers through payment frameworks. CONCLUSIONS: Maximising the impact of a care bundle relies on its successful and timely implementation. Teams implementing the COPD care bundle encountered challenges that were common to all teams and sites. Understanding and learning from the challenges faced by previous endeavours and identifying the facilitators to overcoming these barriers provides an opportunity to mitigate issues that waste time and resources, and ensures that training can be tailored to the anticipated challenges
Fibre Bundles and Generalised Dimensional Reduction
We study some geometrical and topological aspects of the generalised
dimensional reduction of supergravities in D=11 and D=10 dimensions, which give
rise to massive theories in lower dimensions. In these reductions, a global
symmetry is used in order to allow some of the fields to have a non-trivial
dependence on the compactifying coordinates. Global consistency in the internal
space imposes topological restrictions on the parameters of the
compactification as well as the structure of the space itself. Examples that we
consider include the generalised reduction of the type IIA and type IIB
theories on a circle, and also the massive ten-dimensional theory obtained by
the generalised reduction of D=11 supergravity.Comment: 23 pages, Late
On duality symmetries of supergravity invariants
The role of duality symmetries in the construction of counterterms for
maximal supergravity theories is discussed in a field-theoretic context from
different points of view. These are: dimensional reduction, the question of
whether appropriate superspace measures exist and information about non-linear
invariants that can be gleaned from linearised ones. The former allows us to
prove that F-term counterterms cannot be E7(7)-invariant in D=4, N=8
supergravity or E6(6)-invariant in D=5 maximal supergravity. This is confirmed
by the two other methods which can also be applied to D=4 theories with fewer
supersymmetries and allow us to prove that N=6 supergravity is finite at three
and four loops and that N=5 supergravity is three-loop finite.Comment: Clarification of arguments and their consistency with higher
dimensional divergences added, e.g. we prove the 5D 4L non-renormalisation
theorem. The 4L N=6 divergence is also ruled out. References adde
AdS/SCFT in Superspace
A discussion of the AdS/CFT correspondence in IIB is given in a superspace
context. The main emphasis is on the properties of SCFT correlators on the
boundary which are studied using harmonic superspace techniques. These
techniques provide the easiest way of implementing the superconformal Ward
identities. The Ward identities, together with analyticity, can be used to give
a compelling argument in support of the non-renormalisation theorems for two-
and three-point functions, and to establish the triviality of extremal and
next-to-extremal correlation functions. The OPE in is also briefly discussed.Comment: 10 pages; talk given by PSH at 2nd Gursey Memorial Conference, June
200
On the symmetries of special holonomy sigma models
In addition to superconformal symmetry, (1,1) supersymmetric two-dimensional
sigma models on special holonomy manifolds have extra symmetries that are in
one-to-one correspondence with the covariantly constant forms on these
manifolds. The superconformal algebras extended by these symmetries close as
W-algebras, i.e. they have field-dependent structure functions. It is shown
that it is not possible to write down cohomological equations for potential
quantum anomalies when the structure functions are field-dependent. In order to
do this it is necessary to linearise the algebras by treating composite
currents as generators of additional symmetries. It is shown that all cases can
be linearised in a finite number of steps, except for G_2 and SU(3). Additional
problems in the quantisation procedure are briefly discussed.Comment: 16 pages. Abstract improved and a few typographical errors correcte
Solar-cycle variation of the sound-speed asphericity from GONG and MDI data 1995-2000
We study the variation of the frequency splitting coefficients describing the
solar asphericity in both GONG and MDI data, and use these data to investigate
temporal sound-speed variations as a function of both depth and latitude during
the period from 1995-2000 and a little beyond. The temporal variations in even
splitting coefficients are found to be correlated to the corresponding
component of magnetic flux at the solar surface. We confirm that the
sound-speed variations associated with the surface magnetic field are
superficial. Temporally averaged results show a significant excess in sound
speed around 0.92 solar radii and latitude of 60 degrees.Comment: To be published in MNRAS, accepted July 200
Parametrizing the time-variation of the "surface term" of stellar p-mode frequencies: application to helioseismic data
The solar-cyle variation of acoustic mode frequencies has a frequency
dependence related to the inverse mode inertia. The discrepancy between model
predictions and measured oscillation frequencies for solar and solar-type
stellar acoustic modes includes a significant frequency-dependent term known as
the surface term that is also related to the inverse mode inertia. We
parametrize both the surface term and the frequency variations for low-degree
solar data from Birmingham Solar-Oscillations Network (BiSON) and medium-degree
data from the Global Oscillations Network Group (GONG) using the mode inertia
together with cubic and inverse frequency terms. We find that for the central
frequency of rotationally split multiplets the cubic term dominates both the
average surface term and the temporal variation, but for the medium-degree case
the inverse term improves the fit to the temporal variation. We also examine
the variation of the even-order splitting coefficients for the medium-degree
data and find that, as for the central frequency, the latitude-dependent
frequency variation, which reflects the changing latitudinal distribution of
magnetic activity over the solar cycle, can be described by the combination of
a cubic and an inverse function of frequency scaled by inverse mode inertia.
The results suggest that this simple parametrization could be used to assess
the activity-related frequency variation in solar-like asteroseismic targets.Comment: 13 pages, 11 figures. Accepted by MNRAS 13 October 201
Einstein-Weyl structures and Bianchi metrics
We analyse in a systematic way the (non-)compact four dimensional
Einstein-Weyl spaces equipped with a Bianchi metric. We show that Einstein-Weyl
structures with a Class A Bianchi metric have a conformal scalar curvature of
constant sign on the manifold. Moreover, we prove that most of them are
conformally Einstein or conformally K\"ahler ; in the non-exact Einstein-Weyl
case with a Bianchi metric of the type or , we show that the
distance may be taken in a diagonal form and we obtain its explicit
4-parameters expression. This extends our previous analysis, limited to the
diagonal, K\"ahler Bianchi case.Comment: Latex file, 12 pages, a minor modification, accepted for publication
in Class. Quant. Gra
- …