7,542 research outputs found
Formula for Fixed Point Resolution Matrix of Permutation Orbifolds
We find a formula for the resolution of fixed points in extensions of
permutation orbifold conformal field theories by its (half-)integer spin simple
currents. We show that the formula gives a unitary and modular invariant S
matrix.Comment: 42 page
Association between one-hour post-load plasma glucose levels and vascular stiffness in essential hypertension
Objectives: Pulse wave velocity (PWV) is a surrogate end-point for cardiovascular morbidity and mortality. A plasma glucose
value 155 mg/dl (NGT155 had a worse insulin sensitivity and higher hs-CRP than NGT,155, similar to IGT subjects. In addition, NGT 155 subjects, compared with NGT,155, have higher PWV and its hemodynamic correlates
that increase their cardiovascular risk profile
Remote device access in the new accelerator controls middleware
This paper presents the Remote Device Access (RDA) package developed at CERN in the framework of the joint PS/SL Controls Middleware project. The package design reflects the Accelerator Device Model in which devices, named entities in the control system, can be controlled via properties. RDA implements this model in a distributed environment with devices residing in servers that can run anywhere in the controls network. It provides a location-independent and reliable access to the devices from control programs. By invoking the device access methods, clients can read, write and subscribe to device property values. We describe the architecture and design of RDA its API, and CORBA-based implementations in Java and C++. First applications of RDA in the CERN accelerator control systems are described as well
The onset of star formation in primordial haloes
Star formation remains an unsolved problem in astrophysics. Numerical studies
of large-scale structure simulations cannot resolve the whole process and their
approach usually assumes that only gas denser than a typical threshold can host
and form stars. We investigate the onset of cosmological star formation and
compare several very-high-resolution, three-dimensional, N-body/SPH simulations
that include non-equilibrium, atomic and molecular chemistry, star formation
prescriptions, and feedback effects. We study how primordial star formation
depends on gas density thresholds, cosmological parameters and initial set-ups.
For mean-density initial conditions, we find that standard low-density
star-formation threshold (0.2 h^2/cm3) models predict the onset of star
formation at z~25-31, depending on the adopted cosmology. In these models stars
are formed regardless of the time between the moment when the threshold is
reached and the effective runaway collapse. At high redshift, this time
interval represents a significant fraction of the Hubble time and thus this
assumption can induce large artificial off-sets to the onset of star formation.
Choosing higher density thresholds (135 h^2/cm3) allows the entire cooling
process to be followed, and the onset of star formation is then estimated to be
at redshift z~12-16. When isolated, rare, high-density peaks are considered,
the chemical evolution is much faster and the first star formation episodes
occur at z > 40, almost regardless of the choice for the density threshold.
These results could have implications for the formation redshift of the first
cosmological objects, as inferred from direct numerical simulations of
mean-density environments, and on the studies of the reionization history of
the universe.Comment: 10 pages, 1 table, 5 figures; in press. Minor changes don
Family caregivers’ conceptualisation of quality end-of-life care for people with dementia: A qualitative study
BACKGROUND:
People with dementia have been described as the ‘disadvantaged dying’ with poor end-of-life care. Towards the end of life, people with dementia cannot report on the care they receive. It is therefore important to talk to caregivers; however, few have explored the views about end-of-life care from the caregivers’ perspective. The majority of research on family caregivers has focussed on the burden and psychological impact of caring for a relative with dementia.
AIM:
This study aimed to explore the views of family caregivers about quality end-of-life care for people with dementia.
DESIGN:
Qualitative study using in-depth interviews and analysed using thematic analysis.
SETTING/PARTICIPANTS:
Purposive sampling from a third sector organisation’s caregiver network was used to recruit 47 caregivers in England (2012–2013), consisting of (1) family caregivers of someone who had recently received a diagnosis of dementia, (2) family caregivers currently caring for someone with dementia and (3) bereaved family caregivers.
RESULTS:
Three over-arching themes were derived from the interviewees’ discourse, including maintaining the person within, fostering respect and dignity and showing compassion and kindness.
CONCLUSION:
End-of-life care for people with dementia does not differ from care throughout the dementia trajectory. Throughout the findings, there is an implicit underlying theme of conflict: conflict between family caregivers and an increasingly systematised service of care and conflict between family caregivers and professionals. This study has in particular demonstrated the importance of the psycho-social aspects of care, aligning with the holistic definition of palliative care
Cluster scaling relations from cosmological hydrodynamic simulations in dark energy dominated universe
Clusters are potentially powerful tools for cosmology provided their observed
properties such as the Sunyaev-Zel'dovich (SZ) or X-ray signals can be
translated into physical quantities like mass and temperature. Scaling
relations are the appropriate mean to perform this translation. It is
therefore, important to understand their evolution and their modifications with
respect to the physics and to the underlying cosmology. In this spirit, we
investigate the effect of dark energy on the X-ray and SZ scaling relations.
The study is based on the first hydro-simulations of cluster formation for
diferent models of dark energy. We present results for four dark energy models
which differ from each other by their equations of state parameter, .
Namely, we use a cosmological constant model (as a reference), a perfect
fluid with constant equation of state parameter and one with and a scalar field model (or quintessence) with varying . We generate
N-body/hydrodynamic simulations that include radiative cooling with the public
version of the Hydra code, modified to consider an arbitrary dark energy
component. We produce cluster catalogues for the four models and derive the
associated X-ray and SZ scaling relations. We find that dark energy has little
effect on scaling laws making it safe to use the CDM scalings for
conversion of observed quantities into temperature and masses.Comment: 9 pages, 7 figures, submitted to A&
Hadron beam test of a scintillating fibre tracker system for elastic scattering and luminosity measurement in ATLAS
A scintillating fibre tracker is proposed to measure elastic proton
scattering at very small angles in the ATLAS experiment at CERN. The tracker
will be located in so-called Roman Pot units at a distance of 240 m on each
side of the ATLAS interaction point. An initial validation of the design
choices was achieved in a beam test at DESY in a relatively low energy electron
beam and using slow off-the-shelf electronics. Here we report on the results
from a second beam test experiment carried out at CERN, where new detector
prototypes were tested in a high energy hadron beam, using the first version of
the custom designed front-end electronics. The results show an adequate
tracking performance under conditions which are similar to the situation at the
LHC. In addition, the alignment method using so-called overlap detectors was
studied and shown to have the expected precision.Comment: 12 pages, 8 figures. Submitted to Journal of Instrumentation (JINST
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