922017 research outputs found
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A non-linear subdiffusion model for a cell-cell adhesion in chemotaxis
No full textThe purpose of this work is to propose a non-Markovian and nonlinear model of subdiffusive transport that involves adhesion affects the cells escape rates form position x, with chemotaxis. This leads the escape rates to be dependent on the particles density at the neighbours as well as the chemotactic gradient. We systematically derive subdiffusive fractional master equation, then we consider the diffusive limit of the fractional master equation. We finally solve the resulted fractional subdiffusive master equation stationery and analyse the role of adhesion in the resulted stationary density
Politics and Eschatology: Reassessing the Appeal of the “Jewish Indian” Theory in England and New England in the 1650s
No full textThis article examines the “Jewish Indian” theory— which claimed that American Indians were the ten lost tribes of Israel— in 1650s England and New England. The theory found support in England while failing in New England. This difference in reception can be explained by considering its ecclesiological, political, and eschatological implications. Biblical commentators in both England and New England held to a form of “Judeo-Centric” eschatology, which looked for a sudden, miraculous conversion of the Jews and their eventual superiority to Gentile believers. Such beliefs undermined crucial elements of New England ecclesiology when applied to Native Americans. Conversely, the New England Company used the theory in its publications as a fund raising tool in England. These publications impacted upon debates on Jewish readmission to England in the mid-1650s, with New England missionary models suggested as a way of evangelising Jews. This article therefore argues for the importance of understanding eschatological beliefs in local contexts, while demonstrating the way in which such beliefs can be maintained and reoriented in the face of apparent disconfirmation
Reduction of elementary flux mode complexity enables rational metabolic engineering for biotechnological products
No full textOpen innovation evaluation for Internet-enabled services in smart cities
No full textThis article is focused on public service innovation from an innovation management perspective. It presents research experience gained from a European project for managing social and technological innovation in the production and evaluation of demand-driven internet-enabled services in the public sector. It is based on 5 pilot initiatives, which sought to operationalise a new approach to co-producing and co-evaluating civic services in smart cities – commonly referred to as open innovation for smart city services. Research suggests that the evidence base underpinning this approach is not sufficiently robust to support claims being made about its effectiveness. Instead evaluation research of demand-driven internet-enabled urban services is in its infancy and there are no tested methods or tools in the literature for effectively supporting this approach. The paper reports on the development and trialling of a Co-evaluation Framework, indicators and reporting categories, used to support the co-production of citizens-driven smart city services in an EU-funded project. Our point of departure is that innovation of services is a sub-set of innovation management that requires effective integration of technological with social innovation, supported by the right skills and capacities. The main skills sets needed for effective co-evaluation of open innovation services are the integration of stakeholder management with evaluation capacities
Storing renewables in the gas network: modelling of power-to-gas (P2G) seasonal storage flexibility in low carbon power systems
Full text linkThe power-to-gas (P2G) process, whereby excess renewable electrical energy is used to form hydrogen and/or synthetic natural gas that are injected, transported and stored in the gas network, has the prospect to become an important flexibility option for the seasonal storage of low-carbon electricity. This paper is the first to model and assess the potential of P2G when combined with gas seasonal storage operation accounting for the two networks’ characteristics and constraints (including the amount of hydrogen that can be blended with natural gas under different gas network conditions). Power system operation with P2G is analysed via a two-stage optimisation based on DC power flow in order to assess the gas production from otherwise curtailed renewables, also considering impact of P2G on short-term and long-term gas prices. Additionally, impact of P2G on gas network operation and its potentially required re-dispatch are evaluated with a steady-state gas flow model. Case studies conducted on the Great Britain gas and electrical transmission networks quantify benefits and limitations of the integrated usage of P2G with seasonal gas storage under different scenarios. The proposed model thus sets the fundamentals for further development of this emerging technology as a seasonal storage option in low-carbon power systems
Reduction of elementary flux mode complexity enables rational metabolic engineering for biotechnological products
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Stability analysis for time-dependent nonlinear systems. An interval approach
No full textOne of the most important issues in control is determining the stability of a system. Since the 1960’s, Lyapunov-based methods have been developed to determine the stability of linear and nonlinear systems. However, when the system is nonlinear, time-dependent and uncertain, in a set-membership context, stability analysis is challenging and no reliable methods have been developed. This paper proposes an original set-membership based approach for establishing the stability of non-linear, uncertain, time-dependent systems. Two new concepts G-Stability (which is the stability of nonlinear time-dependent uncertain trajectories) and capture tubes (which is an invariant stability region for time-dependent systems) are introduced and illustrated for an autonomous, uncertain, robotic sailboat. Then, G-Stability is used to formulate and prove the safety for a set of capture tubes. This result is then used to analyse the safety of a squad of uncertain, robotic sailboat moving in their environment (no collision among the robots)
Ecologies of educational reflexivity and agency – a different way of thinking about equitable educational policies and practices for England and beyond?
No full textThe current UK education policy for Englandemphasis on equity and social mobility focuses on narrowing the educational attainment gap between more and less advantaged groups of young people – an approach that has strong parallels in many Anglophone countries around the world. We argue that these policy and associated practice proscriptions tend to privilege an individualised narrative of agency for young people, teachers and schools more generally. Our paper argues that this individualised approach is highly problematic in that it decontextualizes the complex and real agentic work of young people in schooling, making it difficult to empirically and theoretically account for differences in educational outcome between and within groups of young people. Informed by a social realist perspective, and in particular the work of Margaret Archer, we propose a theoretical model that we suggest provides greater explanatory and predictive power. The model focuses on the way ecologies of development emerge for young people. We suggest that such ecologies reflect different structural and cultural factors and processes, combining in ways that enable and/or constrain young people’s educational reflexivity and agency and their ensuing educational engagement and attainments. We believe that building a typology of such ecologies of educational reflexivity and agency provides improved ways of developing equitable educational policies and practice - ones that relate clearly to the compositional mix of young people in schools and enable the development of interventions that better relate to such ecologies