102 research outputs found
The evolution of substructure II: linking dynamics to environment
We present results from a series of high-resolution N-body simulations that
focus on the formation and evolution of eight dark matter halos, each of order
a million particles within the virial radius. We follow the time evolution of
hundreds of satellite galaxies with unprecedented time resolution, relating
their physical properties to the differing halo environmental conditions. The
self-consistent cosmological framework in which our analysis was undertaken
allows us to explore satellite disruption within live host potentials, a
natural complement to earlier work conducted within static potentials. Our host
halos were chosen to sample a variety of formation histories, ages, and
triaxialities; despite their obvious differences, we find striking similarities
within the associated substructure populations. Namely, all satellite orbits
follow nearly the same eccentricity distribution with a correlation between
eccentricity and pericentre. We also find that the destruction rate of the
substructure population is nearly independent of the mass, age, and triaxiality
of the host halo. There are, however, subtle differences in the velocity
anisotropy of the satellite distribution. We find that the local velocity bias
at all radii is greater than unity for all halos and this increases as we move
closer to the halo centre, where it varies from 1.1 to 1.4. For the global
velocity bias we find a small but slightly positive bias, although when we
restrict the global velocity bias calculation to satellites that have had at
least one orbit, the bias is essentially removed.Comment: 14 pages, 14 figures, MNRAS in pres
Exploring patterns of recurrent melanoma in Northeast Scotland to inform the introduction a digital self-examination intervention
Peer reviewedPublisher PD
Arc sensitivity to cluster ellipticity, asymmetries and substructures
We investigate how ellipticity, asymmetries and substructures separately
affect the ability of galaxy clusters to produce strong lensing events, i.e.
gravitational arcs, and how they influence the arc morphologies and fluxes.
This is important for those studies aiming, for example, at constraining
cosmological parameters from statistical lensing, or at determining the inner
structure of galaxy clusters through gravitational arcs. We do so by creating
two-dimensional gradually smoothed, differently elliptical and asymmetric
versions of some numerical models. On average, we find that the contributions
of ellipticity, asymmetries and substructures amount to ~40%, ~10% and ~30% of
the total strong lensing cross section, respectively. However, our analysis
shows that substructures play a more important role in less elliptical and
asymmetric clusters, even if located at large distances from the cluster
centers (~1Mpc/h). Conversely, their effect is less important in highly
asymmetric lenses. The morphology, position and flux of individual arcs are
strongly affected by the presence of substructures in the clusters. Removing
substructures on spatial scales <~50kpc/h, roughly corresponding to mass scales
<~5 10^{10}M_\odot/h, alters the image multiplicity of ~35% of the sources used
in the simulations and causes position shifts larger than 5'' for ~40% of the
arcs longer than 5''. We conclude that any model for cluster lens cannot
neglect the effects of ellipticity, asymmetries and substructures. On the other
hand, the high sensitivity of gravitational arcs to deviations from regular,
smooth and symmetric mass distributions suggests that strong gravitational
lensing is potentially a powerfull tool to measure the level of substructures
and asymmetries in clusters.Comment: 16 pages, 18 figures. Accepted version. Version with full resolution
images can be found at
http://www.ita.uni-heidelberg.de/~massimo/sub/publications.htm
Home-based versus centre-based cardiac rehabilitation (Review)
This is the final version. Available from the Cochrane Collaboration via the DOI in this recordBACKGROUND: Cardiovascular disease is the most common cause of death globally. Traditionally, centre-based cardiac rehabilitation programmes are offered to individuals after cardiac events to aid recovery and prevent further cardiac illness. Home-based and technology-supported cardiac rehabilitation programmes have been introduced in an attempt to widen access and participation, especially during the SARS-CoV-2 pandemic. This is an update of a review previously published in 2009, 2015, and 2017. OBJECTIVES: To compare the effect of home-based (which may include digital/telehealth interventions) and supervised centre-based cardiac rehabilitation on mortality and morbidity, exercise-capacity, health-related quality of life, and modifiable cardiac risk factors in patients with heart disease SEARCH METHODS: We updated searches from the previous Cochrane Review by searching the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid), Embase (Ovid), PsycINFO (Ovid) and CINAHL (EBSCO) on 16 September 2022. We also searched two clinical trials registers as well as previous systematic reviews and reference lists of included studies. No language restrictions were applied. SELECTION CRITERIA: We included randomised controlled trials that compared centre-based cardiac rehabilitation (e.g. hospital, sports/community centre) with home-based programmes (± digital/telehealth platforms) in adults with myocardial infarction, angina, heart failure, or who had undergone revascularisation. DATA COLLECTION AND ANALYSIS: Two review authors independently screened all identified references for inclusion based on predefined inclusion criteria. Disagreements were resolved through discussion or by involving a third review author. Two authors independently extracted outcome data and study characteristics and assessed risk of bias. Certainty of evidence was assessed using GRADE. MAIN RESULTS: We included three new trials in this update, bringing a total of 24 trials that have randomised a total of 3046 participants undergoing cardiac rehabilitation. A further nine studies were identified and are awaiting classification. Manual searching of trial registers until 16 September 2022 revealed a further 14 clinical trial registrations - these are ongoing. Participants had a history of acute myocardial infarction, revascularisation, or heart failure. Although there was little evidence of high risk of bias, a number of studies provided insufficient detail to enable assessment of potential risk of bias; in particular, details of generation and concealment of random allocation sequencing and blinding of outcome assessment were poorly reported. No evidence of a difference was seen between home- and centre-based cardiac rehabilitation in our primary outcomes up to 12 months of follow-up: total mortality (risk ratio [RR] = 1.19, 95% confidence interval [CI] 0.65 to 2.16; participants = 1647; studies = 12/comparisons = 14; low-certainty evidence) or exercise capacity (standardised mean difference (SMD) = -0.10, 95% CI -0.24 to 0.04; participants = 2343; studies = 24/comparisons = 28; low-certainty evidence). The majority of evidence (N=71 / 77 comparisons of either total or domain scores) showed no significant difference in health-related quality of life up to 24 months follow-up between home- and centre-based cardiac rehabilitation. Trials were generally of short duration, with only three studies reporting outcomes beyond 12 months (exercise capacity: SMD 0.11, 95% CI -0.01 to 0.23; participants = 1074; studies = 3; moderate-certainty evidence). There was a similar level of trial completion (RR 1.03, 95% CI 0.99 to 1.08; participants = 2638; studies = 22/comparisons = 26; low-certainty evidence) between home-based and centre-based participants. The cost per patient of centre- and home-based programmes was similar. AUTHORS' CONCLUSIONS: This update supports previous conclusions that home- (± digital/telehealth platforms) and centre-based forms of cardiac rehabilitation formally supported by healthcare staff seem to be similarly effective in improving clinical and health-related quality of life outcomes in patients after myocardial infarction, or revascularisation, or with heart failure. This finding supports the continued expansion of healthcare professional supervised home-based cardiac rehabilitation programmes (± digital/telehealth platforms), especially important in the context of the ongoing global SARS-CoV-2 pandemic that has much limited patients in face-to-face access of hospital and community health services. Where settings are able to provide both supervised centre- and home-based programmes, consideration of the preference of the individual patient would seem appropriate. Although not included in the scope of this review, there is an increasing evidence base supporting the use of hybrid models that combine elements of both centre-based and home-based cardiac rehabilitation delivery. Further data are needed to determine: (1) whether the short-term effects of home/digital-telehealth and centre-based cardiac rehabilitation models of delivery can be confirmed in the longer term; (2) the relative clinical effectiveness and safety of home-based programmes for other heart patients, e.g. post-valve surgery and atrial fibrillation.National Institute for Health and Care Research (NIHR
The evolution substructure I: a new identification method
We describe our new "MLAPM-halo-finder" (MHF) which is based on the adaptive
grid structure of the N-body code MLAPM. We then extend the MHF code in order
to track the orbital evolution of gravitationally bound objects through any
given cosmological N-body simulation - our so-called "MLAPM-halo-tracker"
(MHT). The mode of operation of MHT is demonstrated using a series of eight
high-resolution N-body simulations of galaxy clusters. Each of these halos
hosts more than one million particles within their virial radii Rvir. We use
MHT as well as MHF to follow the temporal evolution of hundreds of individual
satellites, and show that the radial distribution of these substructure
satellites follows a "universal" radial distribution irrespective of the host
halo's environment and formation history. This in fact might pose another
problem for simulations of CDM structure formation as there are recent findings
by Taylor et al. (2003) that the Milky Way satellites are found preferentially
closer to the galactic centre and simulations underestimate the amount of
central substructure, respectively. Further, this universal substructure
profile is anti-biased with respect to the underlying dark matter profile. Both
the halo finder MHF and the halo tracker MHT will become part of the open
source MLAPM distribution.Comment: 12 pages, 10 figures, MNRAS in press, the halo finder MHF is
available from http://astronomy.swin.edu.au/MLAP
Substructures in lens galaxies: PG1115+080 and B1555+375, two fold configurations
We study the anomalous flux ratio which is observed in some four-image lens
systems, where the source lies close to a fold caustic. In this case two of the
images are close to the critical curve and their flux ratio should be equal to
unity, instead in several cases the observed value differs significantly. The
most plausible solution is to invoke the presence of substructures, as for
instance predicted by the Cold Dark Matter scenario, located near the two
images. In particular, we analyze the two fold lens systems PG1115+080 and
B1555+375, for which there are not yet satisfactory models which explain the
observed anomalous flux ratios. We add to a smooth lens model, which reproduces
well the positions of the images but not the anomalous fluxes, one or two
substructures described as singular isothermal spheres. For PG1115+080 we
consider a smooth model with the influence of the group of galaxies described
by a SIS and a substructure with mass as well as a
smooth model with an external shear and one substructure with mass . For B1555+375 either a strong external shear or two substructures
with mass reproduce the data quite well.Comment: 26 pages, updated bibliography, Accepted for publication in
Astrophysics & Space Scienc
14-3-3ε Is Required for Germ Cell Migration in Drosophila
Although 14-3-3 proteins participate in multiple biological processes, isoform-specific specialized functions, as well as functional redundancy are emerging with tissue and developmental stage-specificity. Accordingly, the two 14-3-3ε proteins in Drosophila exhibit functional specificity and redundancy. Homozygotes for loss of function alleles of D14-3-3ε contain significantly fewer germ line cells (pole cells) in their gonads, a phenotype not shared by mutants in the other 14-3-3 gene leo. We show that although D14-3-3ε is enriched within pole cells it is required in mesodermal somatic gonad precursor cells which guide pole cells in their migration through the mesoderm and coalesce with them to form the embryonic gonad. Loss of D14-3-3ε results in defective pole cell migration, reduced pole cell number. We present evidence that D14-3-3ε loss results in reduction or loss of the transcription factor Zfh-1, one of the main regulatory molecules of the pole cell migration, from the somatic gonad precursor cells
Cluster Lenses
Clusters of galaxies are the most recently assembled, massive, bound
structures in the Universe. As predicted by General Relativity, given their
masses, clusters strongly deform space-time in their vicinity. Clusters act as
some of the most powerful gravitational lenses in the Universe. Light rays
traversing through clusters from distant sources are hence deflected, and the
resulting images of these distant objects therefore appear distorted and
magnified. Lensing by clusters occurs in two regimes, each with unique
observational signatures. The strong lensing regime is characterized by effects
readily seen by eye, namely, the production of giant arcs, multiple-images, and
arclets. The weak lensing regime is characterized by small deformations in the
shapes of background galaxies only detectable statistically. Cluster lenses
have been exploited successfully to address several important current questions
in cosmology: (i) the study of the lens(es) - understanding cluster mass
distributions and issues pertaining to cluster formation and evolution, as well
as constraining the nature of dark matter; (ii) the study of the lensed objects
- probing the properties of the background lensed galaxy population - which is
statistically at higher redshifts and of lower intrinsic luminosity thus
enabling the probing of galaxy formation at the earliest times right up to the
Dark Ages; and (iii) the study of the geometry of the Universe - as the
strength of lensing depends on the ratios of angular diameter distances between
the lens, source and observer, lens deflections are sensitive to the value of
cosmological parameters and offer a powerful geometric tool to probe Dark
Energy. In this review, we present the basics of cluster lensing and provide a
current status report of the field.Comment: About 120 pages - Published in Open Access at:
http://www.springerlink.com/content/j183018170485723/ . arXiv admin note:
text overlap with arXiv:astro-ph/0504478 and arXiv:1003.3674 by other author
Association of Epstein-Barr virus antibody titers with a human IL-10 promoter polymorphism in Japanese women
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
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