20 research outputs found

    Brane Inflation, Solitons and Cosmological Solutions: I

    Full text link
    In this paper we study various cosmological solutions for a D3/D7 system directly from M-theory with fluxes and M2-branes. In M-theory, these solutions exist only if we incorporate higher derivative corrections from the curvatures as well as G-fluxes. We take these corrections into account and study a number of toy cosmologies, including one with a novel background for the D3/D7 system whose supergravity solution can be completely determined. This new background preserves all the good properties of the original model and opens up avenues to investigate cosmological effects from wrapped branes and brane-antibrane annihilation, to name a few. We also discuss in some detail semilocal defects with higher global symmetries, for example exceptional ones, that could occur in a slightly different regime of our D3/D7 model. We show that the D3/D7 system does have the required ingredients to realise these configurations as non-topological solitons of the theory. These constructions also allow us to give a physical meaning to the existence of certain underlying homogeneous quaternionic Kahler manifolds.Comment: Harvmac, 115 pages, 9 .eps figures; v2: typos corrected, references added and the last section expanded; v3: Few minor typos corrected and references added. Final version to appear in JHE

    A Scholarly Review of Supply Chain Integration within the New Zealand Blueberry Industry

    Get PDF
    Ethics and credence attributes are the humanistic basis for establishing sustainable supply chain development. It determines brand reputation, ecology and customer experience. Furthermore, good ethics and credence Attributes promote the progress of industry leadership and increase the possibility of win-win strategies, especially in terms of negotiation. Negotiation is the premise of supply chain collaboration. The purpose of collaboration is to establish a synchronized supply chain to improve the ability of industry coordination. This is also the key to creating value, and the importance of risk management cannot be ignored. It is not only a guarantee for the smooth operation of the supply chain, but also an important measure to improve the flexibility of the supply chain. Finally, the results of supply chain integration need to rely on performance metrics and benchmarking to control and improve the overall performance of the supply chain. This publication evaluates modern theories in all these areas and contextualise it to the New Zealand blueberry industry. It is important that the reader appreciates the scholarly origin of this publication

    Modelling faba bean production in an uncertain future climate

    No full text
    Future climate change may bring risk or benefit to crop production. In this paper, the possible impact of climate change on faba bean production in Scotland is examined. Instead of conventional simulation modelling techniques, the belief network approach is applied to deal with the uncertain information associated with climate prediction. A belief network is constructed which relates faba bean growth and development to weather according to an agricultural expert's advice. The existing FABEAN model and a weather generator are used to generate data to train the belief network, so that it can answer queries on faba bean production under various climate predictions. Using a range of possible future climate scenarios, we have shown that the predictions given by the belief networks can represent accurately those from the exhaustive runs of a simulation model, and in a more efficient way. The possibility of combining belief network techniques with Geographical Information Systems (GIS) as a means of scaling from local to regional predictions for crop production is also discussed

    Regulator of Calcineurin 1 helps coordinate whole-body metabolism and thermogenesis

    No full text
    Increasing non-shivering thermogenesis (NST), which expends calories as heat rather than storing them as fat, is championed as an effective way to combat obesity and metabolic disease. Innate mechanisms constraining the capacity for NST present a fundamental limitation to this approach, yet are not well understood. Here, we provide evidence that Regulator of Calcineurin 1 (RCAN1), a feedback inhibitor of the calcium-activated protein phosphatase calcineurin (CN), acts to suppress two distinctly different mechanisms of non-shivering thermogenesis (NST): one involving the activation of UCP1 expression in white adipose tissue, the other mediated by sarcolipin (SLN) in skeletal muscle. UCP1 generates heat at the expense of reducing ATP production, whereas SLN increases ATP consumption to generate heat. Gene expression profiles demonstrate a high correlation between Rcan1 expression and metabolic syndrome. On an evolutionary timescale, in the context of limited food resources, systemic suppression of prolonged NST by RCAN1 might have been beneficial; however, in the face of caloric abundance, RCAN1-mediated suppression of these adaptive avenues of energy expenditure may now contribute to the growing epidemic of obesity.David Rotter, Heshan Peiris, D Bennett Grinsfelder, Alyce M Martin, Jana Burchfield ... Claire F Jessup ... et al
    corecore