23,759 research outputs found
Attracted Diffusion-Limited Aggregation
In this paper, we present results of extensive Monte Carlo simulations of
diffusion-limited aggregation (DLA) with a seed placed on an attractive plane
as a simple model in connection with the electrical double layers. We compute
the fractal dimension of the aggregated patterns as a function of the
attraction strength \alpha. For the patterns grown in both two and three
dimensions, the fractal dimension shows a significant dependence on the
attraction strength for small values of \alpha, and approaches to that of the
ordinary two-dimensional (2D) DLA in the limit of large \alpha. For
non-attracting case with \alpha=1, our results in three dimensions reproduce
the patterns of 3D ordinary DLA, while in two dimensions our model leads to
formation of a compact cluster with dimension two. For intermediate \alpha, the
3D clusters have quasi-2D structure with a fractal dimension very close to that
of the ordinary 2D-DLA. This allows one to control morphology of a growing
cluster by tuning a single external parameter \alpha.Comment: 6 pages, 6 figures, to appear in Phys. Rev. E (2012
New light on the ‘Drummer of Tedworth’: conflicting narratives of witchcraft in Restoration England
This paper presents a definitive text of hitherto little-known early documents concerning ‘The Drummer of Tedworth’, a poltergeist case that occurred in 1662-3 and became famous not least due to its promotion by Joseph Glanvill in his demonological work, Saducismus Triumphatus. On the basis of these and other sources, it is shown how responses to the events at Tedworth evolved from anxious piety on the part of their victim, John Mompesson, to confident apologetic by Glanvill, before they were further affected by the emergence of articulate scepticism about the case
Label-free proteomics identifies Calreticulin and GRP75/Mortalin as peripherally accessible protein biomarkers for spinal muscular atrophy
BACKGROUND: Spinal muscular atrophy (SMA) is a neuromuscular disease resulting from mutations in the survival motor neuron 1 (SMN1) gene. Recent breakthroughs in preclinical research have highlighted several potential novel therapies for SMA, increasing the need for robust and sensitive clinical trial platforms for evaluating their effectiveness in human patient cohorts. Given that most clinical trials for SMA are likely to involve young children, there is a need for validated molecular biomarkers to assist with monitoring disease progression and establishing the effectiveness of therapies being tested. Proteomics technologies have recently been highlighted as a potentially powerful tool for such biomarker discovery. METHODS: We utilized label-free proteomics to identify individual proteins in pathologically-affected skeletal muscle from SMA mice that report directly on disease status. Quantitative fluorescent western blotting was then used to assess whether protein biomarkers were robustly changed in muscle, skin and blood from another mouse model of SMA, as well as in a small cohort of human SMA patient muscle biopsies. RESULTS: By comparing the protein composition of skeletal muscle in SMA mice at a pre-symptomatic time-point with the muscle proteome at a late-symptomatic time-point we identified increased expression of both Calreticulin and GRP75/Mortalin as robust indicators of disease progression in SMA mice. We report that these protein biomarkers were consistently modified in different mouse models of SMA, as well as across multiple skeletal muscles, and were also measurable in skin biopsies. Furthermore, Calreticulin and GRP75/Mortalin were measurable in muscle biopsy samples from human SMA patients. CONCLUSIONS: We conclude that label-free proteomics technology provides a powerful platform for biomarker identification in SMA, revealing Calreticulin and GRP75/Mortalin as peripherally accessible protein biomarkers capable of reporting on disease progression in samples of muscle and skin
Piloting a manualised weight management programme (Shape Up-LD) for overweight and obese persons with mild-moderate learning disabilities: study protocol for a pilot randomised controlled trial
National obesity rates have dramatically risen over the last decade. Being obese significantly reduces life expectancy, increases the risk of a range of diseases, and compromises quality of life. Costs to both the National Health Service and society are high. An increased prevalence of obesity in people with learning disabilities has been demonstrated. The consequences of obesity are particularly relevant to people with learning disabilities who are already confronted by health and social inequalities. In order to provide healthcare for all, and ensure equality of treatment for people with learning disabilities, services must be developed specifically with this population in mind. The aim of this project is to pilot the evaluation of a manualised weight management programme for overweight and obese persons with mild-moderate learning disabilities (Shape Up-LD)
The effects of peer influence on adolescent pedestrian road-crossing decisions
Objective: Adolescence is a high-risk period for pedestrian injury. It is also a time of heightened susceptibility to peer influence. The aim of this research was to examine the effects of peer influence on the pedestrian road-crossing decisions of adolescents.
Methods: Using 10 videos of road-crossing sites, 80 16- to 18-year-olds were asked to make pedestrian road-crossing decisions. Participants were assigned to one of 4 experimental conditions: negative peer (influencing unsafe decisions), positive peer (influencing cautious decisions), silent peer (who observed but did not comment), and no peer (the participant completed the task alone). Peers from the adolescent’s own friendship group were recruited to influence either an unsafe or a cautious decision.
Results: Statistically significant differences were found between peer conditions. Participants least often identified safe road-crossing
sites when accompanied by a negative peer and more frequently identified dangerous road-crossing sites when accompanied by a positive peer. Both cautious and unsafe comments from a peer influenced adolescent pedestrians’ decisions.
Conclusions: These findings showed that road-crossing decisions of adolescents were influenced by both unsafe and cautious comments from their peers. The discussion highlighted the role that peers can play in both increasing and reducing adolescent risk-taking
A panel analysis of UK industrial company failure
We examine the failure determinants for large quoted UK industrials using a panel data set
comprising 539 firms observed over the period 1988-93. The empirical design employs data
from company accounts and is based on Chamberlain’s conditional binomial logit model,
which allows for unobservable, firm-specific, time-invariant factors associated with failure
risk. We find a noticeable degree of heterogeneity across the sample companies. Our panel
results show that, after controlling for unobservables, lower liquidity measured by the quick
assets ratio, slower turnover proxied by the ratio of debtors turnover, and profitability were
linked to the higher risk of insolvency in the analysis period. The findings appear to support
the proposition that the current cash-flow considerations, rather than the future prospects of
the firm, determined company failures over the 1990s recession
Equation level matching: An extension of the method of matched asymptotic expansion for problems of wave propagation
We introduce an alternative to the method of matched asymptotic expansions.
In the "traditional" implementation, approximate solutions, valid in different
(but overlapping) regions are matched by using "intermediate" variables. Here
we propose to match at the level of the equations involved, via a "uniform
expansion" whose equations enfold those of the approximations to be matched.
This has the advantage that one does not need to explicitly solve the
asymptotic equations to do the matching, which can be quite impossible for some
problems. In addition, it allows matching to proceed in certain wave situations
where the traditional approach fails because the time behaviors differ (e.g.,
one of the expansions does not include dissipation). On the other hand, this
approach does not provide the fairly explicit approximations resulting from
standard matching. In fact, this is not even its aim, which to produce the
"simplest" set of equations that capture the behavior
From transformative learning to social change? Using action research to explore and improve informal complaints management in an NHS trust
Background: The number of complaints concerning aspects of care from patients and/or carers have increased over time. Yet, in spite of a growing body of national and international literature on health care complaints there is a lack of knowledge around how nurses and midwives manage informal complaints at ward level, or staff needs in relation to this.
Aim: Using an Action research (AR) approach with mixed methods, four phases and four cycles, the aim was to explore informal complaints management by nurses and midwives at ward level. We discuss the AR process primarily in connection with learning and service change, drawing from the qualitative data in this paper.
Findings: The analysis of the collected qualitative data resulted in three main themes related to the complexities of complaints and complaints management, staff support needs and the existing ambiguous complaints systems which are hard for both staff and servicer users to negotiate. The AR approach facilitated learning and change in participants in relation to views on complaints management, and the main issues around complaints management in the collaborating trust.
Conclusions: The extant body of research on complaints does not sufficiently recognise the complexity of complaints and informal complaints management or the complaints systems in place. Needs based staff training can help support staff to manage informal complaints more effectively
Chandra Observation of an X-ray Flare at Saturn: Evidence for Direct Solar Control on Saturn's Disk X-ray Emissions
Saturn was observed by Chandra ACIS-S on 20 and 26-27 January 2004 for one
full Saturn rotation (10.7 hr) at each epoch. We report here the first
observation of an X-ray flare from Saturn's non-auroral (low-latitude) disk,
which is seen in direct response to an M6-class flare emanating from a sunspot
that was clearly visible from both Saturn and Earth. Saturn's disk X-ray
emissions are found to be variable on time scales of hours to weeks to months,
and correlated with solar F10.7 cm flux. Unlike Jupiter, X-rays from Saturn's
polar (auroral) region have characteristics similar to those from its disk.
This report, combined with earlier studies, establishes that disk X-ray
emissions of the giant planets Saturn and Jupiter are directly regulated by
processes happening on the Sun. We suggest that these emissions could be
monitored to study X-ray flaring from solar active regions when they are on the
far side and not visible to Near-Earth space weather satellites.Comment: Total 12 pages including 4 figure
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