134 research outputs found

    The Impact of Eruption Source Parameter Uncertainties on Ash Dispersion Forecasts During Explosive Volcanic Eruptions

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    Volcanic ash in the atmosphere is a hazard to aviation. To predict which areas of airspace are most likely to be affected by the presence of ash, Volcanic Ash Advisory Centers (VAACs) use observations and atmospheric dispersion models. These models are initialized with, among other parameters, a mass eruption rate (MER), which quantifies the emission rate into the atmosphere at the source. This influences the predicted spatial–temporal evolution and concentration of the ash cloud. Different models are available to estimate MER from the volcanic plume height and some models also include the weather conditions (e.g., wind speed). The REFIR software tool uses time‐series of plume height estimated from observations and weather data to provide estimates of MER through time. Here we present an updated version of REFIR that can now be used also to calculate MER for past eruptions and produce output parameters in a format suitable for use with the NAME dispersion model (UK Met Office—London VAAC). We also investigate how uncertainty in input parameters is propagated through to dispersion model output. Our results show that a +/−1 km uncertainty on a 6 km high plume can result in the affected area ranging by a factor of three between the minimum and maximum estimates. Additionally, we show that using wind‐affected plume models results in affected areas that are five times larger than using no‐wind‐affected models. This demonstrates the sensitivity of MER to the type of plume model chosen (no‐wind‐ vs. wind‐affected)

    A relational approach to understanding inhabitants’ engagement with Photovoltaic (PV) technology in homes

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    Photovoltaic (PV) systems have been promoted in the UK housing sector as a key strategy for meeting carbon reduction commitments by offsetting the use of the non-renewable grid energy with renewable energy. However, inhabitants are not changing their routine energy consumption practices to take advantage of off-grid day time solar energy and, in some cases, even shifting practices away from the initial intentions underlying the technology. This means that the necessary energy savings from new housing are not being achieved. In this paper, this is attributed to the variation in the provisioning of PV technology in new homes, as well as inhabitants’ engagement with and know-how of PV technologies, subject to explicit rules and policies. The key contribution of this paper is to reveal how PV technologies and inhabitants interact within different socio-technological home contexts drawing on Practice theory and ethnographic methods applied to four housing developments in England

    Domestic photovoltaic systems: the governance of occupant use

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    Housing is responsible for 29% of all CO2 emissions in the UK, yet there is still limited understanding of why housing routinely uses more energy than predicted, resulting in a performance gap. Recent studies attribute this gap to insufficient use of energy-efficient technologies by occupants. This paper focuses on the governance of domestic photovoltaic (PV) systems in the UK during the provision stage, an overlooked area in the previous energy-efficiency studies that have mainly focused on PV adoption and practices by occupants, but only after installation. The notion of translation in Actor Network Theory (ANT) is used to analyse how a network of PV provision actants decides the system design and integration into homes, and how this in turn conditions household participation in this network. Semi-structured interviews and video tours used in four participative community and two non-participative community case studies reveal the impact of non-human actants in terms of how PV scripts and practices are formed by PV professionals. The findings also shows that the nominated ‘procurement occupants’ were the key mediators in the participative projects, while the housing developers were the key mediators in the non participative projects

    Ending Neglect of older people in the response to Humanitarian Emergencies

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    Older people make up a significant and growing number of those affected by humanitarian crises, yet they are often not sought out or prioritised within the humanitarian response. Humanitarian agencies, donors, and international bodies neglect older people's health and nutrition. The gaps in knowledge and research about the needs of older people in emergencies are considerable. Older people are not monitored in emergencies and they are not prioritised despite evidence of disproportionate mortality and morbidity in this group. We call for policy changes by humanitarian agencies and donors to ensure that the needs of this vulnerable group are met

    Widespread tephra dispersal and ignimbrite emplacement from a subglacial volcano (Torfajökull, Iceland)

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    The tephra dispersal mechanisms of rhyolitic glaciovolcanic eruptions are little known, but can be investigated through the correlation of eruptive products across multiple depositional settings. Using geochemistry and geochronology, we correlate a regionally important Pleistocene tephra horizon—the rhyolitic component of North Atlantic Ash Zone II (II-RHY-1)—and the ThĂłrsmörk Ignimbrite with rhyolitic tuyas at Torfajökull volcano, Iceland. The eruption breached an ice mass >400 m thick, leading to the widespread dispersal of II-RHY-1 across the North Atlantic and the Greenland ice sheet. Locally, pyroclastic density currents traveled across the ice surface, depositing the variably welded ThĂłrsmörk Ignimbrite beyond the ice margin and ~30 km from source. The widely dispersed products of this eruption represent a valuable isochronous tie line between terrestrial, marine, and ice-core paleoenvironmental records. Using the tephra horizon, estimates of ice thickness and extent derived from the eruption deposits can be directly linked to the regional climate archive, which records the eruption at the onset of Greenland Stadial 15.2

    High-throughput chemogenetic drug screening reveals PKC-RhoA/PKN as a targetable signaling vulnerability in GNAQ-driven uveal melanoma

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    Uveal melanoma (UM) is the most prevalent cancer of the eye in adults, driven by activating mutation of GNAQ/GNA11; however, there are limited therapies against UM and metastatic UM (mUM). Here, we perform a high-throughput chemogenetic drug screen in GNAQ-mutant UM contrasted with BRAF-mutant cutaneous melanoma, defining the druggable landscape of these distinct melanoma subtypes. Across all compounds, darovasertib demonstrates the highest preferential activity against UM. Our investigation reveals that darovasertib potently inhibits PKC as well as PKN/PRK, an AGC kinase family that is part of the "dark kinome." We find that downstream of the Gαq-RhoA signaling axis, PKN converges with ROCK to control FAK, a mediator of non-canonical Gαq-driven signaling. Strikingly, darovasertib synergizes with FAK inhibitors to halt UM growth and promote cytotoxic cell death in vitro and in preclinical metastatic mouse models, thus exposing a signaling vulnerability that can be exploited as a multimodal precision therapy against mUM.</p

    Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

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    Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
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