816 research outputs found
Bayesian estimation and reconstruction of marine surface contaminant dispersion
Discharge of hazardous substances into the marine environment poses a
substantial risk to both public health and the ecosystem. In such incidents, it
is imperative to accurately estimate the release strength of the source and
reconstruct the spatio-temporal dispersion of the substances based on the
collected measurements. In this study, we propose an integrated estimation
framework to tackle this challenge, which can be used in conjunction with a
sensor network or a mobile sensor for environment monitoring. We employ the
fundamental convection-diffusion partial differential equation (PDE) to
represent the general dispersion of a physical quantity in a non-uniform flow
field. The PDE model is spatially discretised into a linear state-space model
using the dynamic transient finite-element method (FEM) so that the
characterisation of time-varying dispersion can be cast into the problem of
inferring the model states from sensor measurements. We also consider imperfect
sensing phenomena, including miss-detection and signal quantisation, which are
frequently encountered when using a sensor network. This complicated sensor
process introduces nonlinearity into the Bayesian estimation process. A
Rao-Blackwellised particle filter (RBPF) is designed to provide an effective
solution by exploiting the linear structure of the state-space model, whereas
the nonlinearity of the measurement model can be handled by Monte Carlo
approximation with particles. The proposed framework is validated using a
simulated oil spill incident in the Baltic sea with real ocean flow data. The
results show the efficacy of the developed spatio-temporal dispersion model and
estimation schemes in the presence of imperfect measurements. Moreover, the
parameter selection process is discussed, along with some comparison studies to
illustrate the advantages of the proposed algorithm over existing methods
The process of establishing implementing and maintaining a social support infant feeding programme
Objective To describe the process of establishing and implementing a social support infant feeding intervention.
Design This paper outlines the initial stages of a randomised controlled trial which assessed the effectiveness of a social support intervention on a range of infant feeding outcomes. Details are presented of the processes involved in recruiting, training and supporting a group of volunteers who provided support to the study sample.
Setting Camden and Islington, London, UK.
Results Initial networking with local agencies and organisations provided invaluable information and contacts. Employing a dedicated volunteer co-ordinator is vitally important in the recruitment, training and support of volunteers. Providing child care and travel expenses is an essential incentive for volunteers with young children. Advertisements placed in local newspapers were the most successful means of recruiting volunteers. Appropriate training is needed to equip volunteers with the necessary knowledge and skills to provide effective support. Particular emphasis in the training focused upon developing the necessary interpersonal skills and self-confidence. The evaluation of the training programme demonstrated that it improved volunteers’ knowledge and reported confidence. The provision of ongoing support is also essential to maintain volunteers’ interest and enthusiasm. The retention of volunteers is, however, a key challenge.
Conclusions The processes outlined in this paper have demonstrated the feasibility of successfully establishing, implementing and maintaining a community-based social support infant feeding programme. The experiences described provide useful insights into the practical issues that need to be addressed in setting up a social support intervention
Platelet count and transfusion requirements during moderate or severe postpartum haemorrhage
Limited data exist on platelet transfusion during postpartum haemorrhage. We retrospectively analysed a consecutive cohort from a single centre of 347 women with moderate or severe postpartum haemorrhage, transfused according to national guidelines. Twelve (3%) women required a platelet transfusion. There were no differences between women who did and did not receive platelets with respect to age, mode of initiation of labour or mode of delivery. Women receiving a platelet transfusion had a lower median (IQR [range]) platelet count at study entry than women who did not receive platelets before haemorrhage (135 (97–175 [26–259])×109.l−1 vs 224 (186–274 [91–1006])×109.l−1), respectively), and at diagnosis of postpartum haemorrhage (median 114 (78–153 [58–238])×109.l−1 vs 193 (155–243 [78–762])×109.l−1 respectively). Six women were thrombocytopenic pre-delivery. The cause of haemorrhage that was associated with the highest rate of platelet transfusion was placental abruption, with three of 14 women being transfused. If antenatal thrombocytopenia or consumptive coagulopathy were not present, platelets were only required for haemorrhage > 5000 ml. Early formulaic platelet transfusion would have resulted in many women receiving platelets unnecessarily. Using current guidelines, the need for platelet transfusion is uncommon without antenatal thrombocytopenia, consumptive coagulopathy or haemorrhage > 5000 ml. We found no evidence to support early fixed-ratio platelet transfusion
Proceedings of the Salford Postgraduate Annual Research Conference (SPARC) 2011
These proceedings bring together a selection of papers from the 2011 Salford Postgraduate Annual Research Conference(SPARC). It includes papers from PhD students in the arts and social sciences, business, computing, science and engineering, education, environment, built environment and health sciences. Contributions from Salford researchers are published here alongside papers from students at the Universities of Anglia Ruskin, Birmingham City, Chester,De Montfort, Exeter, Leeds, Liverpool, Liverpool John Moores and Manchester
Spatial and temporal variability of the concentration field from localized releases in a regular building array
Spatial and temporal fluctuations in the concentration field from an ensemble of continuous point-source releases in a regular building array are analyzed from data generated by direct numerical simulations. The release is of a passive scalar under conditions of neutral stability. Results are related to the underlying flow structure by contrasting data for an imposed wind direction of 0 deg and 45 deg relative to the buildings. Furthermore, the effects of distance from the source and vicinity to the plume centreline on the spatial and temporal variability are documented. The general picture that emerges is that this particular geometry splits the flow domain into segments (e.g. “streets” and “intersections”) in each of which the air is, to a first approximation, well mixed. Notable exceptions to this general rule include regions close to the source, near the plume edge, and in unobstructed channels when the flow is aligned. In the oblique (45 deg) case the strongly three-dimensional nature of the flow enhances mixing of a scalar within the canopy leading to reduced temporal and spatial concentration fluctuations within the plume core. These fluctuations are in general larger for the parallel flow (0 deg) case, especially so in the long unobstructed channels. Due to the more complex flow structure in the canyon-type streets behind buildings, fluctuations are lower than in the open channels, though still substantially larger than for oblique flow. These results are relevant to the formulation of simple models for dispersion in urban areas and to the quantification of the uncertainties in their predictions
Orthotopic liver transplantation for acute and subacute hepatic failure in adults
The role of liver transplantation in 29 patients with fulminant and subacute hepatic failure due to a variety of different causes was examined by comparing the outcome and a variety of “hospitalization” variables. Transplanted patients (n = 13) were more likely to survive (p < 0.05), were younger (p < 0.05) and spent more time in the hospital (p < 0.025) than did those who were not transplanted (n = 16). Despite spending a much longer time in the hospital, transplanted patients spent less time in the intensive care unit (p < 0.05) in coma (p < 0.01) and on a respirator (p < 0.01) than did those not transplanted. Most importantly, the survival rate for transplanted patients was significantly improved (p < 0.05) as compared to those not transplanted. We conclude that liver transplantation can be applied successfully to the difficult clinical problem of fulminant and subacute hepatic failure. Copyright © 1987 American Association for the Study of Liver Disease
Schopenhauer on suicide and negation of the will
ABSTRACT Schopenhauer's argument against suicide has served as a punching bag for many modern-day commentators. Dale Jacquette, Sandra Shapshay, and David Hamlyn all argue that the premises of this argument or its conclusion are inconsistent with Schopenhauer's wider metaphysical and ethical project. This paper defends Schopenhauer from these charges. Along the way, it examines the relations between suicide, death by voluntary starvation, negation of the will, compassion, and Schopenhauer's critiques of cynicism and stoicism. The paper concludes that there may be gaps in Schopenhauer's system, but not where the aforementioned commentators tried to locate them
Women, resettlement and desistance
With the numbers of women imprisoned increasing across Western jurisdictions over the last 15 or so years, so too have the numbers of women returning to the community following a period in custody. Despite increasing policy attention in the UK and elsewhere to prisoner resettlement, women’s experiences on release from prison have received limited empirical and policy attention. Drawing upon interviews with women leaving prison in Victoria, Australia, this article discusses the resettlement challenges faced by the women and highlights their similarity to the experiences of women leaving prison in other jurisdictions. Women had mixed (and predominantly negative) experiences and views of accessing services and supports following release, though experiences of parole supervision by community corrections officers were often positive, especially if women felt valued and supported by workers who demonstrated genuine concern. Analysis of factors associated with further offending and with desistance, points to the critical role of flexible, tailored and women-centred post-release support building, and, where possible, upon relationships established with women while they are still in prison
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