848 research outputs found

    What is going wrong with community engagement? How flood communities and flood authorities construct engagement and partnership working

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    In this paper, we discuss the need for flood risk management in England that engages stakeholders with flooding and its management processes, including knowledge gathering, planning and decision-making. By comparing and contrasting how flood communities experience ‘community engagement’ and ‘partnership working’, through the medium of an online questionnaire, with the process’s and ways of working that the Environment Agency use when ‘working with others’, we demonstrate that flood risk management is caught up in technocratic ways of working derived from long-standing historical practices of defending agricultural land from water. Despite the desire to move towards more democratised ways of working which enable an integrated approach to managing flood risk, the technocratic framing still pervades contemporary flood risk management. We establish that this can disconnect society from flooding and negatively impacts the implementation of more participatory approaches designed to engage flood communities in partnership working. Through the research in this paper it becomes clear that adopting a stepwise, one-size-fits-all approach to engagement fails to recognise that communities are heterogenous and that good engagement requires gaining an understanding of the social dimensions of a community. Successful engagement takes time, effort and the establishment of trust and utilises social learning and pooling of knowledge to create a better understanding of flooding, and that this can lead to increasing societal connectivity to flooding and its impacts

    A PIV comparison of the flow field and wall shear stress in rigid and compliant models of healthy carotid arteries

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    Certain systems relevant to circulatory disease have walls which are neither rigid nor static, for example, the coronary arteries, the carotid artery and the heart chambers. In vitro modeling allows the fluid mechanics of the circulatory system to be studied without the ethical and safety issues associated with animal and human experiments. Computational methods in which the equations are coupled governing the flow and the elastic walls are maturing. Currently there is a lack of experimental data in compliant arterial systems to validate the numerical predictions. Previous experimental work has commonly used rigid wall boundaries, ignoring the effect of wall compliance. Particle Image Velocimetry is used to provide a direct comparison of both the flow field and wall shear stress (WSS) observed in experimental phantoms of rigid and compliant geometries representing an idealized common carotid artery. The input flow waveform and the mechanical response of the phantom are physiologically realistic. The results show that compliance affects the velocity profile within the artery. A rigid boundary causes severe overestimation of the peak WSS with a maximum relative difference of 61% occurring; showing compliance protects the artery from exposure to high magnitude WSS. This is important when trying to understand the development of diseases like atherosclerosis. The maximum, minimum and time averaged WSS in the rigid geometry was 2.3, 0.51 and 1.03Pa and in the compliant geometry 1.4, 0.58 and 0.84Pa, respectively

    Perturbed cholesterol and vesicular trafficking associated with dengue blocking in Wolbachia-infected Aedes aegypti cells

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    Wolbachia are intracellular maternally inherited bacteria that can spread through insect populations and block virus transmission by mosquitoes, providing an important approach to dengue control. To better understand the mechanisms of virus inhibition, we here perform proteomic quantification of the effects of Wolbachia in Aedes aegypti mosquito cells and midgut. Perturbations are observed in vesicular trafficking, lipid metabolism and in the endoplasmic reticulum that could impact viral entry and replication. Wolbachia-infected cells display a differential cholesterol profile, including elevated levels of esterified cholesterol, that is consistent with perturbed intracellular cholesterol trafficking. Cyclodextrins have been shown to reverse lipid accumulation defects in cells with disrupted cholesterol homeostasis. Treatment of Wolbachia-infected Ae. aegypti cells with 2-hydroxypropyl-β-cyclodextrin restores dengue replication in Wolbachia-carrying cells, suggesting dengue is inhibited in Wolbachia-infected cells by localised cholesterol accumulation. These results demonstrate parallels between the cellular Wolbachia viral inhibition phenotype and lipid storage genetic disorders

    Modelling nasal high flow therapy effects on upper airway resistance and resistive work of breathing

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    Aim The goal of this paper is to quantify upper airway resistance with and without nasal high flow (NHF) therapy. For adults, NHF therapy feeds 30–60 L/min of warm humidified air into the nose through short cannulas which do not seal the nostril. NHF therapy has been reported to increase airway pressure, increase tidal volume (Vt) and decrease respiratory rate (RR), but it is unclear how these findings affect the work done to overcome airway resistance to air flow during expiration. Also, there is little information on how the choice of nasal cannula size may affect work of breathing. In this paper, estimates of airway resistance without and with different NHF flow (applied via different cannula sizes) were made. The breathing efforts required to overcome airway resistance under these conditions were quantified. Method NHF was applied via three different cannula sizes to a 3-D printed human upper airway. Pressure drop and flow rate were measured and used to estimate inspiratory and expiratory upper airway resistances. The resistance information was used to compute the muscular work required to overcome the resistance of the upper airway to flow. Results NHF raises expiratory resistance relative to spontaneous breathing if the breathing pattern does not change but reduces work of breathing if peak expiratory flow falls. Of the cannula sizes used, the large cannula produced the greatest resistance and the small cannula produced the least. The work required to cause tracheal flow through the upper airway was reduced if the RR and minute volume are reduced by NHF. NHF has been observed to do so in COPD patients (Bräunlich et al., 2013). A reduction in I:E ratio due to therapy was found to reduce work of breathing if the peak inspiratory flow is less than the flow below which no inspiratory effort is required to overcome upper airway resistance. Conclusion NHF raises expiratory resistance but it can reduce the work required to overcome upper airway resistance via a fall in inspiratory work of breathing, RR and minute volume

    Análisis comparativo entre un tutor circular y uno monolateral en elongaciones óseas

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    El presente trabajo compara la funcionalidad de dos tutores externos utilizados para elongación: el del Dr. Ilizarov y el tutor HG, desarrollado en nuestra institución. De 131 pacientes tratados con elongación ósea en 147 huesos largos se seleccionaron al azar 25 huesos por cada aparato anteriormente mencionado. Para objetivar los resultados se registraron estadísticamente variables independientes y dependientes en sus características subjetivas y objetivas, tales como: edad, sexo, tipo de hueso elongado, tolerancia psíquica, sensación de confort, facilidad de higiene y control, las infecciones, las rigideces articulares por retracción músculo tendinosa, y la deformación ósea residual. El objetivo fue comparar y establecer si el cambio en la elección del sistema fue ventajoso para nuestros pacientes. En el intento comparativo se enfrentaron dos variables, que a nuestro criterio eran las más importantes para establecer diferencias: la calidad del callo del hueso sometido a elongación y la presencia de complicaciones tanto transitorias como definitivas.In this work we compare the results obtained with two different external fixation devices in patients undergoing bone lengthening. The devices studied were the Ilizarov type and the HG, an apparatons developed in our institution. Out of 131 patientes treated by bone lengthening in 147 long bones, 25 bones lengthened with each device were selected at random. Different subjective and objective variables were assessed: age, sex, type of bone, psichological tolerance, patients, confort, nursing, infections, joint stiffness due to musculotendinous retractions, and residual bone deformity. The aim of the study was to analyze if the monolateral frame entailed advantages for our patients. Two main factors were more deeply analysed, namely the quality of the bone callus subjected to lengthening and the presence of both transitory and definitive complications

    Civic Geographies of Architectural Enthusiasm

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    Our decision to take part in the civic geographies exhibition was motivated by a desire to explore some of the resonances between notions of what civic geographies might look like in theory, but also in practice. We based our contribution upon our British Academy funded research that focuses on how twentieth century architecture is understood, valued, cared for and protected by members of The Twentieth Century Society[1]. The group was initiated to safeguard Britain’s post-1914 architectural heritage. At the end of 2012, the Society’s membership stood just under 2000, made up of architects (retired and in practice), architecture students, builders, civil servants involved in planning, as well as other interested publics. Lobbying, campaigns and casework are central to the Society’s activities, for example in the early nineties the Society persuaded the National Trust to take on the Hampstead house of the Hungarian émigré architect Erno Goldfinger at 2 Willow Road, London, NW3 (see Figure 1). Employing two full-time and two part-time staff, the Society has a statutory role in relation to twentieth century listed buildings in England. This means that local planning authorities have to consult the Society in relation to any threats of demolition or alterations

    The Wolbachia strain wAu provides highly efficient virus transmission blocking in Aedes aegypti

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    Introduced transinfections of the inherited bacteria Wolbachia can inhibit transmission of viruses by Aedes mosquitoes, and in Ae. aegypti are now being deployed for dengue control in a number of countries. Only three Wolbachia strains from the large number that exist in nature have to date been introduced and characterized in this species. Here novel Ae. aegypti transinfections were generated using the wAlbA and wAu strains. In its native Ae. albopictus, wAlbA is maintained at lower density than the co-infecting wAlbB, but following transfer to Ae. aegypti the relative strain density was reversed, illustrating the strain-specific nature of Wolbachia-host co-adaptation in determining density. The wAu strain also reached high densities in Ae. aegypti, and provided highly efficient transmission blocking of dengue and Zika viruses. Both wAu and wAlbA were less susceptible than wMel to density reduction/incomplete maternal transmission resulting from elevated larval rearing temperatures. Although wAu does not induce cytoplasmic incompatibility (CI), it was stably combined with a CI-inducing strain as a superinfection, and this would facilitate its spread into wild populations. Wolbachia wAu provides a very promising new option for arbovirus control, particularly for deployment in hot tropical climates

    Experimental measurement of breath exit velocity and expirated bloodstain patterns produced under different exhalation mechanisms

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    In an attempt to obtain a deeper understanding of the factors which determine the characteristics of expirated bloodstain patterns, the mechanism of formation of airborne droplets was studied. Hot wire anemometry measured air velocity, 25 mm from the lips, for 31 individuals spitting, coughing and blowing. Expirated stains were produced by the same mechanisms performed by one individual with different volumes of a synthetic blood substitute in their mouth. The atomization of the liquid at the lips was captured with high-speed video, and the resulting stain patterns were captured on paper targets. Peak air velocities varied for blowing (6 to 64 m/s), spitting (1 to 64 m/s) and coughing (1 to 47 m/s), with mean values of 12 m/s (blowing), 7 m/s (spitting) and 4 m/s (coughing). There was a large (55–65%) variation between individuals in air velocity produced, as well as variation between trials for a single individual (25–35%). Spitting and blowing involved similar lip shapes. Blowing had a longer duration of airflow, though it is not the duration but the peak velocity at the beginning of the air motion which appears to control the atomization of blood in the mouth and thus stain formation. Spitting could project quantities of drops at least 1600 mm. Coughing had a shorter range of near 500 mm, with a few droplets travelling further. All mechanisms could spread drops over an angle >45°. Spitting was the most effective for projecting drops of blood from the mouth, due to its combination of chest motion and mouth shape producing strong air velocities. No unique method was found of inferring the physical action (spitting, coughing or blowing) from characteristics of the pattern, except possibly distance travelled. Diameter range in expirated bloodstains varied from very small (<1 mm) in a dense formation to several millimetres. No unique method was found of discriminating expirated patterns from gunshot or impact patterns on stain shape alone. Only 20% of the expirated patterns produced in this study contained identifiable bubble rings or beaded stains

    Rheometry based on free surface velocity

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    This paper explores the possibility of identifying the rheology of a fluid by monitoring how the free surface velocity field is affected by a perturbation in the flow. The dam-break problem is considered which results from the release of a gate initially separating two fluid pools of different depth. The flow velocity is measured by seeding the free surface with buoyant particles and using Particle Tracking Velocimetry. In parallel, a mathematical model based on the lubrication approximation for fluids with a power-law rheology is developed. The model is validated against a similarity solution which is obtained for the spreading of a gravity current under its own weight and neglecting surface tension. Minimizing the difference between the free surface velocity fields obtained numerically and measured experimentally enables the identification of rheological parameters. The methodology is tested on ideal and noisy synthetic data sets and experimental data obtained with aqueous glycerol
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