7 research outputs found

    Implementation of a land use and spatial interaction model based on random utility choices and social accounting matrices

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    Random utility modelling has been established as one of the main paradigms for the implementation of land use and transport interaction (LUTI) models. Despite widespread application of such models, the respective literature provides relatively little detail on the theoretical consistency of the overall formal framework of the random utility based LUTI models. To address this gap, we present a detailed formal description of a generic land use and spatial interaction model that adheres to the random utility paradigm through the explicit distinction between utility and cost across all processes that imply behaviour of agents. The model is rooted in an extended input-output table, with the workforce and households accounts being disaggregated by socio-economic type. Similarly, the land account is broken down by domestic and non-domestic land use types. The model is developed around two processes. Firstly, the generation of demand for inputs required by established production; the estimation of the level of demand between sectors, households and land use types is supported by social accounting techniques. When appropriate the implicit production functions are assumed depended on costs of inputs, which gives rise to price-elastic demands. Secondly, the spatial assignment of demanded inputs (industrial activity, workforce, land) to locations of production; here sequences of decisions are used to distribute demand (both spatially and, when necessary, a-spatially) and to propagate costs and utilities of production and consumption that emerge from imbalances between supply and demand. The implementation of this generic model is discussed in relation to the case of the Greater South East region of the UK, including London, the South East and the East of England. We present the calibration process, data requirements, necessary assumptions and resulting implications. We discuss outputs under various land use strategies and economic scenarios, such as regulated versus competing land uses, constrained versus unconstrained densities, and high versus low economic and population growth rates. By adjusting the design constraints of the spatial planning and infrastructure supply strategies we aim to improve their sustainability.

    LUISA: a land-use interaction with social accounting model; presentation and enhanced calibration method

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    Random utility modelling has been established as one of the main paradigms for the implementation of land-use spatial interaction (LUSI) models. We present a detailed formal description of a LUSI model that adheres to the random utility paradigm through the explicit distinction between utility and cost across all processes that represent the behaviour of agents. The model is rooted in a social accounting matrix, with the workforce and households accounts being disaggregated by socioeconomic type. Similarly, the land account is broken down by domestic and nondomestic land-use types. The model is developed around two processes. Firstly, the generation of demand for inputs required by established production; when appropriate the implicit production functions are assumed to depend on costs of inputs, which give rise to price-elastic demands. And, secondly, the spatial assignment of demanded inputs to locations of their production; here sequences of decisions are used to distribute demand both spatially and aspatially, and to propagate costs and utilities of production and consumption that emerge from imbalances between supply and demand. The implementation of this generic model is discussed in relation to the case of the UK. The model has been developed for testing the sustainability of integrated economic, spatial development policies, and output information for estimating urban form and the potential for decentralised technologies. The inputs include area-wide socioeconomic forecasts and the allocation policy of urban land. The outputs include the spatial allocation of activities and prices of labour, goods and services, land, and floorspace. They are combined with the land inputs to estimate the changes in the density of urban form and activities. These outputs can then be used to estimate the demands for infrastructure services and the potential for decentralised infrastructure supply. We focus primarily on the calibration process and its methodological implications, including a method of refining the calibration and demonstrate how this improves the spatial representation of the utility of land. <br/

    A Triphenylphosphonium-Functionalized Mitochondriotropic Nanocarrier for Efficient Co-Delivery of Doxorubicin and Chloroquine and Enhanced Antineoplastic Activity

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    Drug delivery systems that target subcellular organelles and, in particular, mitochondria are considered to have great potential in treating disorders that are associated with mitochondrial dysfunction, including cancer or neurodegenerative diseases. To this end, a novel hyperbranched mitochondriotropic nanocarrier was developed for the efficient co-delivery of two different (both in chemical and pharmacological terms) bioactive compounds. The carrier is based on hyperbranched poly(ethyleneimine) functionalized with triphenylphosphonium groups that forms ~100 nm diameter nanoparticles in aqueous media and can encapsulate doxorubicin (DOX), a well-known anti-cancer drug, and chloroquine (CQ), a known chemosensitizer with arising potential in anticancer medication. The anticancer activity of this system against two aggressive DOX-resistant human prostate adenocarcinoma cell lines and in in vivo animal studies was assessed. The co-administration of encapsulated DOX and CQ leads to improved cell proliferation inhibition at extremely low DOX concentrations (0.25 ÎĽÎś). In vivo experiments against DU145 human prostate cancer cells grafted on immunodeficient mice resulted in tumor growth arrest during the three-week administration period and no pervasive side effects. The findings put forward the potential of such targeted low dose combination treatments as a therapeutic scheme with minimal adverse effects
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