11,829 research outputs found

    Developing corporate knowledge and a BAA plc policy position on aircraft emissions and climate change.

    Get PDF
    The aviation sector is faced with a difficult sustainability challenge. It is one of the fastest growing global industries, with a projected growth rate of 5% a year and an important rote in the global economy yet it is believed to have a moderate but rising impact on the global climate through the emission of global warming gases into the atmosphere. Indeed air travel is now the worlds’ fastest growing source of climate change emissions. In response to this sustainability dilemma, this work based research initiative aims to take forward BAA plc's (formerly the British Airports Authority) sustainable development (SD) programme and develop a BAA policy position on aircraft emissions and climate change. The initiative intended to make an impact in two main areas; firstly in developing BAA's awareness and understanding of the issue of aircraft emissions and climate change and its relevance to the business and secondly in the development of a BAA policy position and action plan to address the issue. The work has resulted in a published policy position on aircraft emissions and climate change (Appendix 6.7) and a process which has served to increase the awareness and understanding of the issue within BAA (Chapter 4, 5, 6). An action plan designed to implement this strategy has also been developed (Appendix 7.1). The project also presents a model for sustainability policy development in BAA (Chapter 7) and serves to demonstrate the role of the work based researcher in a business and sustainability policy making setting (section 7.7) In Chapters seven and eight of the project summary, two sets of recommendations are presented; one aimed at BAA, considers how the business should take forward its SD programme, in relation to climate change (Section 7.8). The other is aimed at sustainability professionals embarking on similar policy development initiatives or change management roles in the private sector/ public sector (Chapter 8). In addition, the research prompted the company to question its understanding of SD and its environmental responsibilities as a leading airport business and that of its customers, the airlines. As a result the initiative assisted in widening the scope of BAA's SD programme and has encouraged the development of a number of other work streams, which are currently underway. These include the development of an internal leadership model for SD, a sectoral influencing strategy and a review of BAA's conceptual understanding of SD (Appendices 7.2, 7.4)

    Social learning and information sharing: an evolutionary simulation model of foraging in Norway rats

    Get PDF
    Social learning is distinguished from innate behaviour and individual learning as a behavioural strategy. We investigate simple mechanisms for social learning in an evolutionary simulation of food-preference copying in Norway rats. These animals learn preferences by interacting with conspecifics, but, unexpectedly, they fail to learn aversions after interacting with a poisoned demonstrator. They also follow each other for food sites. Simulation results show that failure to discriminate between sick and healthy demonstrators may be due to food toxicity in foraging environments. A seemingly complex instance of social information transmission is explained through the action of simple behaviours in an appropriately structured environment

    Aquaculture for African smallholders

    Get PDF
    Small scale aquaculture, Integrated farming, Aquaculture systems, Appropriate technology, Malawi, Agribusiness,

    The Benefish consortium 24 month report WP6: productivity modelling of OWI's and welfare intervention measures

    Get PDF
    In order to accurately model all costs and benefits associated with welfare interventions for farmed fish it is necessary to establish how any welfare actions affect productivity. Productivity modelling within Benefish has been conducted in WP6. WP6 aimed to model relationships between welfare interventions, changes in OWI’s and measures of productivity. It did so focusing only on the effects which were biological in nature: economic costs and benefits attributed to changes in productivity are addressed in WP8

    Critical fluctuations of noisy period-doubling maps

    Full text link
    We extend the theory of quasipotentials in dynamical systems by calculating, within a broad class of period-doubling maps, an exact potential for the critical fluctuations of pitchfork bifurcations in the weak noise limit. These far-from-equilibrium fluctuations are described by finite-size mean field theory, placing their static properties in the same universality class as the Ising model on a complete graph. We demonstrate that the effective system size of noisy period-doubling bifurcations exhibits universal scaling behavior along period-doubling routes to chaos.Comment: 11 pages, 5 figure

    IL-12 and IL-4 activate a CD39-dependent intrinsic peripheral tolerance mechanism in CD8+ T cells

    Get PDF
    Immune responses to protein antigens involve CD4+ and CD8+ T cells, which follow distinct programs of differentiation. Naïve CD8 T cells rapidly develop cytotoxic T-cell (CTL) activity after T-cell receptor stimulation, and we have previously shown that this is accompanied by suppressive activity in the presence of specific cytokines, i.e. IL-12 and IL-4. Cytokine-induced CD8+ regulatory T (Treg) cells are one of several Treg-cell phenotypes and are Foxp3− IL-10+ with contact-dependent suppressive capacity. Here, we show they also express high level CD39, an ecto-nucleotidase that degrades extracellular ATP, and this contributes to their suppressive activity. CD39 expression was found to be upregulated on CD8+ T cells during peripheral tolerance induction in vivo, accompanied by release of IL-12 and IL-10. CD39 was also upregulated during respiratory tolerance induction to inhaled allergen and on tumor-infiltrating CD8+ T cells. Production of IL-10 and expression of CD39 by CD8+ T cells was independently regulated, being respectively blocked by extracellular ATP and enhanced by an A2A adenosine receptor agonist. Our results suggest that any CTL can develop suppressive activity when exposed to specific cytokines in the absence of alarmins. Thus negative feedback controls CTL expansion under regulation from both nucleotide and cytokine environment within tissues

    Management of plant health risks associated with processing of plant-based wastes: A review

    Get PDF
    The rise in international trade of plants and plant products has increased the risk of introduction and spread of plant pathogens and pests. In addition, new risks are arising from the implementation of more environmentally friendly methods of biodegradable waste disposal, such as composting and anaerobic digestion. As these disposal methods do not involve sterilisation, there is good evidence that certain plant pathogens and pests can survive these processes. The temperature/time profile of the disposal process is the most significant and easily defined factor in controlling plant pathogens and pests. In this review, the current evidence for temperature/time effects on plant pathogens and pests is summarised. The advantages and disadvantages of direct and indirect process validation for the verification of composting processes, to determine their efficacy in destroying plant pathogens and pests in biowaste, are discussed. The availability of detection technology and its appropriateness for assessing the survival of quarantine organisms is also reviewed

    Development, initial validation and reliability testing of a web-based, generic feline health-related quality of life instrument

    Get PDF
    Objectives: The objective of this study was to develop a valid, reliable web-based, generic feline health-related quality-of-life (HRQoL) questionnaire instrument to measure the affective impact of chronic disease. Methods: A large initial item pool, obtained through interviews with cat owners, was reduced using predetermined criteria, survey scores for relevance and clarity, and the ability of individual items to discriminate between healthy and sick cats when owners completed a prototype questionnaire. Using these data, factor analysis was used to derive a scoring algorithm and provide evidence for factorial validity. Validity was demonstrated further in a field trial using a ‘known groups’ approach (sick vs healthy cats will have a different HRQoL profile, and the HRQoL profile of cats will deteriorate as comorbidities increase). Test–retest reliability was assessed using intra-class correlation coefficients (ICC). Results: In total, 165 items were reduced to 20 and, on the basis of a factor analysis that explained 72.3% of the variation in scores input by 71 owners of 30 healthy and 41 sick cats using the prototype, these were allocated to three domains (vitality, comfort and emotional wellbeing [EWB]) with a scoring algorithm derived using item loadings. Subsequently, the owners of 36 healthy and 58 sick cats completed one or two (n = 48) assessments. Median scores (healthy vs sick) for all domains were significantly different (P <0.001), 78% of cats were correctly classified as healthy or sick and for comorbidities the correlation coefficients were moderate (vitality 0.64; comfort 0.63; EWB 0.50). Test–retest reliability was good (ICC vitality 0.635; comfort 0.716; EWB 0.853). Conclusions and relevance: This study provides initial evidence for the validity and reliability of a novel HRQoL instrument to aid the assessment and management of chronic diseases of cats
    • …
    corecore