5,283 research outputs found

    Economic and social factors in designing disease control strategies for epidemics on networks

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    Models for control of epidemics on local, global and small-world networks are considered, with only partial information accessible about the status of individuals and their connections. The main goal of an effective control measure is to stop the epidemic at a lowest possible cost, including treatment and cost necessary to track the disease spread. We show that delay in detection of infectious individuals and presence of long-range links are the most important factors determining the cost. However, the details of long-range links are usually the least-known element of the social interactions due to their occasional character and potentially short life-span. We show that under some conditions on the probability of disease spread, it is advisable to attempt to track those links. Thus, collecting some additional knowledge about the network structure might be beneficial to ensure a successful and cost-effective control.Comment: To be published in Acta Phys. Pol.

    Electrically Conductive Paints for Satellites

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    A program was conducted to develop and test electrically conductive paint coatings for spacecraft. A wide variety of organic and inorganic coatings were formulated using conductive binders, conductive pigments, and similar approaches. Z-93, IITRI's standard specification inorganic thermal control coating, exhibits good electrical properties and is a very space-stable coating system. Several coatings based on a conductive pigment (antimony-doped tin oxide) in silicone and silicate binders offer considerable promise. Paint systems using commercially available conductive polymers also appear to be of interest, but will require substantial development. Evaluations were made based on electrical conductivity, paint physical properties, and the stability of spectral reflectance in space environment testing

    Fundamental investigation of ultraviolet radiation effects in polymeric film-forming materials

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    A literature search from 1958 to present was conducted on the effect of ultraviolet radiation on polymeric materials, with particular emphasis on vacuum photolysis, mechanisms of degradation, and energy transfer phenomena. The literature from 1958 to 1968 was searched manually, while the literature from 1968 to present was searched by using a computerized keyword system. The primary objective was to provide the necessary background information for the design of new or modified materials with improved stability to the vacuum-radiation environment of space

    A study of compressible turbulent boundary layers using the method of invariant modeling

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    Model equations for studying compressible turbulen boundary layer

    Controlling disease spread on networks with incomplete knowledge

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    Models for control of highly infectious diseases on local, small-world, and scale-free networks are considered, with only partial information accessible about the status of individuals and their connections. We consider a case when individuals can be infectious before showing symptoms and thus before detection. For small to moderately severe incidence of infection with a small number of nonlocal links, it is possible to control disease spread by using purely local methods applied in a neighborhood centered around a detected infectious individual. There exists an optimal radius for such a control neighborhood leading to the lowest severity of the epidemic in terms of economic costs associated with disease and treatment. The efficiency of a local control strategy is very sensitive to the choice of the radius. Below the optimal radius, the local strategy is unsuccessful; the disease spreads throughout the system, necessitating treatment of the whole population. At the other extreme, a strategy involving a neighborhood that is too large controls the disease but is wasteful of resources. It is not possible to stop an epidemic on scale-free networks by preventive actions, unless a large proportion of the population is treated

    Optimising control of disease spread on networks

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    We consider models for control of epidemics on local, global, small-world and scale-free networks, with only partial information accessible about the status of individuals and their connections. The effectiveness of local (e.g. ring vaccination or culling) vs global (e.g. random vaccination) control measures is evaluated, with the aim of minimising the total cost of an epidemic. The costs include direct costs of treating infected individuals as well as costs of treatment. We first consider a random (global) vaccination strategy designed to stop any potential outbreak. We show that if the costs of the preventive vaccination are ignored, the optimal strategy is to vaccinate the whole population, although most of the resources are wasted on preventing a small number of cases. If the vaccination costs are included, or if a local strategy (within a certain neighbourhood of a symptomatic individual) is chosen, there is an optimum number of treated individuals. Inclusion of non-local contacts (,small-worlds' or scale-free networks) increases the levels of preventive (random) vaccination and radius of local treatment necessary for stopping the outbreak at a minimal cost. The number of initial foci also influences our choice of optimal strategy. The size of epidemics and the number of treated individuals increase for outbreaks that are initiated from a larger number of initial foci, but the optimal radius of local control actually decreases. The results are important for designing control strategies based on cost effectiveness

    Recommendations from recent graduates in medicine, nursing and pharmacy on improving interprofessional education in university programs: A qualitative study

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    Background: Interprofessional education (IPE) has been recognized as an innovative approach for the development of a collaborative, practice-ready health workforce, but is not used consistently in undergraduate health professional programs. We sought to explore the reflections of graduates on the IPE experiences they had during their undergraduate education and training. It was anticipated that having completed their pre-vocational education and spent up to two years working in a clinical environment, recent graduates would be well-placed to provide insights into the value of the IPE opportunities they had, and to suggest approaches for improving these opportunities in undergraduate programs. Methods. This study was part of a larger research project (Interprofessional Education for the Quality use of Medicines; IPE for QuM) which used focus groups as part of an interpretive research design to inform other aspects of the research. Here, we report on focus groups with recent graduates recruited from area health services across Australia. Results: Sixty-eight recent graduates working in New South Wales, Western Australia, and Tasmania participated in 12 focus group sessions. In this paper, we report on new graduates' reflections on their experiences of IPE as part of their university degree, as well as their recommendations to improve interprofessional education before graduation. The new graduates were unanimous in valuing IPE from their current perspective of being in the health workforce. Most IPE experiences recalled were regarded as positive, but those valued most highly were experiences that involved genuine engagement and opportunities to interact with students in other professions working on a relevant problem. Clinical placement was a missed opportunity with few structured meaningful interprofessional learning experiences. Surprisingly there was little social contact between professions in universities even when programs were co-located, thus reinforcing professional silos. Conclusions: The graduates provided many insightful reflections about the value of university-based IPE and their preparedness for clinical practice. Although universally acclaimed as a good idea there is much room for improvement. We put forward a set of suggestions to improve IPE and guide the design of future IPE efforts. © 2014 Gilligan et al.; licensee BioMed Central Ltd

    Epidemics in Networks of Spatially Correlated Three-dimensional Root Branching Structures

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    Using digitized images of the three-dimensional, branching structures for root systems of bean seedlings, together with analytical and numerical methods that map a common 'SIR' epidemiological model onto the bond percolation problem, we show how the spatially-correlated branching structures of plant roots affect transmission efficiencies, and hence the invasion criterion, for a soil-borne pathogen as it spreads through ensembles of morphologically complex hosts. We conclude that the inherent heterogeneities in transmissibilities arising from correlations in the degrees of overlap between neighbouring plants, render a population of root systems less susceptible to epidemic invasion than a corresponding homogeneous system. Several components of morphological complexity are analysed that contribute to disorder and heterogeneities in transmissibility of infection. Anisotropy in root shape is shown to increase resilience to epidemic invasion, while increasing the degree of branching enhances the spread of epidemics in the population of roots. Some extension of the methods for other epidemiological systems are discussed.Comment: 21 pages, 8 figure

    Intestinal barrier tightening by a cell-penetrating antibody to Bin1, a candidate target for immunotherapy of ulcerative colitis.

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    Patients afflicted with ulcerative colitis (UC) are at increased risk of colorectal cancer. While its causes are not fully understood, UC is associated with defects in colonic epithelial barriers that sustain inflammation of the colon mucosa caused by recruitment of lymphocytes and neutrophils into the lamina propria. Based on genetic evidence that attenuation of the bridging integrator 1 (Bin1) gene can limit UC pathogenicity in animals, we have explored Bin1 targeting as a therapeutic option. Early feasibility studies in the dextran sodium sulfate mouse model of experimental colitis showed that administration of a cell-penetrating Bin1 monoclonal antibody (Bin1 mAb 99D) could prevent lesion formation in the colon mucosa in part by preventing rupture of lymphoid follicles. In vivo administration of Bin1 mAb altered tight junction protein expression and cecal barrier function. Strikingly, electrophysiology studies in organ cultures showed that Bin1 mAb could elevate resistance and lowe

    Negotiating professional and social voices in research principles and practice

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    This paper draws on work conducted for a qualitative interview based study which explores the gendered racialised and professional identifications of health and social care professionals. Participants for the project were drawn from the professional executive committees of recently formed Primary Care Trusts. The paper discusses how the feminist psychosocial methodological approach developed for the project is theoretically, practically and ethically useful in exploring the voices of those in positions of relative power in relation to both health and social care services and the social relations of gender and ethnicity. The approach draws on psychodynamic accounts of (defended) subjectivity and the feminist work of Carol Gilligan on a voice-centred relational methodology. Coupling the feminist with the psychosocial facilitates an emphasis on voice and dialogic communication between participant and researcher not always captured in psychosocial approaches which tend towards favouring the interviewer as ‘good listener’. This emphasis on dialogue is important in research contexts where prior and ongoing relationships with professional participants make it difficult and indeed undesirable for researchers to maintain silence
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