327 research outputs found

    Observations of High Definition Symmetric Quasi‐Periodic Scintillations in the Mid‐Latitude Ionosphere With LOFAR

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    We present broadband ionospheric scintillation observations of highly defined symmetric quasi‐periodic scintillations (QPS: Maruyama, 1991, https://doi.org/10.1029/91rs00357) caused by plasma structures in the mid‐latitude ionosphere using the LOw Frequency ARray (LOFAR: van Haarlem et al., 2013, https://doi.org/10.1051/0004‐6361/201220873). Two case studies are shown, one from 15 December 2016, and one from 30 January 2018, in which well‐defined main signal fades are observed to be bounded by secondary diffraction fringing. The ionospheric plasma structures effectively behave as a Fresnel obstacle, in which steep plasma gradients at the periphery result in a series of decreasing intensity interference fringes, while the center of the structures largely block the incoming radio signal altogether. In particular, the broadband observing capabilities of LOFAR permit us to see considerable frequency dependent behavior in the QPSs which, to our knowledge, is a new result. We extract some of the clearest examples of scintillation arcs reported in an ionospheric context, from delay‐Doppler spectral analysis of these two events. These arcs permit the extraction of propagation velocities for the plasma structures causing the QPSs ranging from 50 to 00 m s−1, depending on the assumed altitude. The spacing between the individual plasma structures ranges between 5 and 20 km. The periodicities of the main signal fades in each event and, in the case of the 2018 data, co‐temporal ionosonde data, suggest the propagation of the plasma structures causing the QPSs are in the E‐region. Each of the two events is accurately reproduced using a thin screen phase model. Individual signal fades and enhancements were modeled using small variations in total electron content (TEC) amplitudes of order 1 mTECu, demonstrating the sensitivity of LOFAR to very small fluctuations in ionospheric plasma density. To our knowledge these results are among the most detailed observations and modeling of QPSs in the literature

    Observations of High Definition Symmetric Quasi‐Periodic Scintillations in the Mid‐Latitude Ionosphere With LOFAR

    Get PDF
    We present broadband ionospheric scintillation observations of highly defined symmetric quasi‐periodic scintillations (QPS: Maruyama, 1991, https://doi.org/10.1029/91rs00357) caused by plasma structures in the mid‐latitude ionosphere using the LOw Frequency ARray (LOFAR: van Haarlem et al., 2013, https://doi.org/10.1051/0004‐6361/201220873). Two case studies are shown, one from 15 December 2016, and one from 30 January 2018, in which well‐defined main signal fades are observed to be bounded by secondary diffraction fringing. The ionospheric plasma structures effectively behave as a Fresnel obstacle, in which steep plasma gradients at the periphery result in a series of decreasing intensity interference fringes, while the center of the structures largely block the incoming radio signal altogether. In particular, the broadband observing capabilities of LOFAR permit us to see considerable frequency dependent behavior in the QPSs which, to our knowledge, is a new result. We extract some of the clearest examples of scintillation arcs reported in an ionospheric context, from delay‐Doppler spectral analysis of these two events. These arcs permit the extraction of propagation velocities for the plasma structures causing the QPSs ranging from 50 to 00 m s−1, depending on the assumed altitude. The spacing between the individual plasma structures ranges between 5 and 20 km. The periodicities of the main signal fades in each event and, in the case of the 2018 data, co‐temporal ionosonde data, suggest the propagation of the plasma structures causing the QPSs are in the E‐region. Each of the two events is accurately reproduced using a thin screen phase model. Individual signal fades and enhancements were modeled using small variations in total electron content (TEC) amplitudes of order 1 mTECu, demonstrating the sensitivity of LOFAR to very small fluctuations in ionospheric plasma density. To our knowledge these results are among the most detailed observations and modeling of QPSs in the literature

    Incorporating hydrology into climate suitability models changes projections of malaria transmission in Africa

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    Continental-scale models of malaria climate suitability typically couple well-established temperature-response models with basic estimates of vector habitat availability using rainfall as a proxy. Here we show that across continental Africa, the estimated geographic range of climatic suitability for malaria transmission is more sensitive to the precipitation threshold than the thermal response curve applied. To address this problem we use downscaled daily climate predictions from seven GCMs to run a continental-scale hydrological model for a process-based representation of mosquito breeding habitat availability. A more complex pattern of malaria suitability emerges as water is routed through drainage networks and river corridors serve as year-round transmission foci. The estimated hydro-climatically suitable area for stable malaria transmission is smaller than previous models suggest and shows only a very small increase in state-of-the-art future climate scenarios. However, bigger geographical shifts are observed than with most rainfall threshold models and the pattern of that shift is very different when using a hydrological model to estimate surface water availability for vector breeding

    Developing a model of best practice for teams managing crisis in people with dementia: a consensus approach

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    BACKGROUND: Teams delivering crisis resolution services for people with dementia and their carers provide short-term interventions to prevent admission to acute care settings. There is great variation in these services across the UK. This article reports on a consensus process undertaken to devise a Best Practice Model and evaluation Tool for use with teams managing crisis in dementia. METHODS: The Best Practice Model and Tool were developed over a three stage process: (i) Evidence gathering and generation of candidate standards (systematic review and scoping survey, interviews and focus groups); (ii) Prioritisation and selection of standards (consultation groups, a consensus conference and modified Delphi process); (iii) Refining and operationalising standards (consultation group and field-testing). RESULTS: One hundred sixty-five candidate standards arose from the evidence gathering stage; were refined and reduced to 90 through a consultation group exercise; and then reduced to 50 during the consensus conference and weighted using a modified Delphi process. Standards were then operationalised through a clinical consultation group and field-tested with 11 crisis teams and 5 non-crisis teams. Scores ranged from 48 to 92/100. The median score for the crisis teams was 74.5 (range 67-92), and the median score for non-crisis teams was 60 (range 48-72). CONCLUSIONS: With further psychometric testing, this Best Practice Model and Tool will be ideal for the planning, improvement and national benchmarking of teams managing dementia crises in the future

    School toilets : queer, disabled bodies and gendered lessons of embodiment

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    In this paper we argue that school toilets function as one civilising site (Elias, 1978) in which children learn that disabled and queer bodies are out of place. This paper is the first to offer queer and crip perspectives on school toilets. The small body of existing school toilet literature generally works from a normative position which implicitly perpetuates dominant and oppressive ideals. We draw on data from Around the Toilet, a collaborative research project with queer, trans and disabled people (aroundthetoilet.wordpress.com) to critically interrogate this work. In doing this we consider ‘toilet training’ as a form of ‘civilisation’, that teaches lessons around identity, embodiment and ab/normal ways of being in the world. Furthermore, we show that ‘toilet training’ continues into adulthood, albeit in ways that are less easily identifiable than in the early years. We therefore call for a more critical, inclusive, and transformative approach to school toilet research

    A critique of Paulo Freire’s perspective on human nature to inform the construction of theoretical underpinnings for research

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    From Crossref via Jisc Publications RouterHistory: epub 2020-04-20, issued 2020-04-20Article version: VoRKate Sanders - ORCID 0000-0003-3516-7030 https://orcid.org/0000-0003-3516-7030This article presents a critique of Paulo Freire's philosophical perspective on human nature in the context of a doctoral research study to explore “muchness” or nurses’ subjective experience of well‐being; and demonstrates how this critique has informed the refinement of the theoretical principles used to inform research methodology and methods. Engaging in philosophical groundwork is essential for research coherence and integrity. Through this groundwork, largely informed by Freire's critical pedagogy and his ideas on humanization, I recognized the need to clarify my understanding of the concepts of persons and personhood and how this related to Freire's use of the term human beings. This clarification process is essential to ensure congruence between the theoretical principles that I draw from his work and my beliefs about persons, personhood and person‐centredness. The article begins with a brief introduction to the research, followed by an overview of Freire's philosophical perspectives, and subsequently, the critique process is presented and discussed. This process involved engaging with the vast literature and debates about what it means to be a person, to make sense of the often complex and contradictory arguments. Eventually, three headings emerged that helped me to frame my evolving understanding: Our species: human beings ; The kind that we are: human nature ; and This person that I am: personhood. Through this process of exploration, I recognized that Freire's perspective on human nature (a) foregrounded cognitive rationality, which presented itself as a limitation when considering my ontological beliefs and the focus of my research, leading me to draw on the work of Mark Johnson and his ideas about embodiment to help me to further develop my theoretical principles; (b) focused on the “collective” rather than individuals, which is a shortcoming in relation to person‐centred research that acknowledges the uniqueness of participants.21pubpub

    Enhanced surface water flood forecasts: User-led development and testing

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    The risk of surface water flooding (SWF) in England is already high and its frequency and severity is projected to increase in the future. SWF generally occurs due to intense, highly localised rainfall, which is challenging to forecast with sufficient accuracy to take proactive action ahead of flood events. Being able to manage the risk effectively lies in improved rainfall and flood forecast products, better communication of uncertainty and building the capacity of local responders. This study utilises state-of-the-art high-resolution ensemble rainfall forecasts and hydraulic modelling tools alongside a novel post-processing method to develop and trial new SWF forecast products within an incident workshop attended by forecast producers and regional forecast users. Twenty-two of 24 workshop participants reported that the new information would be useful to their organisation but more product development and training in its interpretation is required. Specific recommendations to improve SWF forecast provision include increased support for local government through a single government organisation responsible for SWF, making more use of existing static SWF mapping in a real-time context and employing the process of user-based consultation, as outlined in this study, to guide the future development of future SWF forecast information and processes
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