An Ambiguity Aversion Framework of Security Game under Ambiguities

Security is a critical concern around the world. Since resources for security are always limited, lots of interest have arisen in using game theory to handle security resource allocation problems. However, most of the existing work does not address adequately how a defender chooses his optimal strategy in a game with absent, inaccurate, uncertain, and even ambiguous strategy profiles' payoffs. To address this issue, we propose a general framework of security games under ambiguities based on Dempster-Shafer theory and the ambiguity aversion principle of minimax regret. Then, we reveal some properties of this framework. Also, we present two methods to reduce the influence of complete ignorance. Our investigation shows that this new framework is better in handling security resource allocation problems under ambiguities.

Chemosensory learning in the chicken embryo

Examined how exposure to a chemosensory stimulus prior to hatching affects subsequent chemosensory preferences of newly hatched chicks. The chicks' preferences were assessed at 2 days after hatching using an olfactory preference test (strawberry-smelling shavings vs water-coated shavings) and at 4 days after hatching using a gustatory preference test (strawberry-flavoured water vs unflavoured water). With no exposure to strawberry before hatching, strawberry was highly aversive to chicks after hatching. However, following exposure to strawberry before hatching, chicks expressed a greater preference for (or weaker aversion to) the strawberry stimulus. Chicks exposed to strawberry before hatching drank more strawberry-flavoured water and spent more time in a strawberry-scented area than chicks having no exposure before hatching. This change in preference was specific to the stimulus experienced before hatching and was present in the absence of any posthatching exposure to the stimulus. Results demonstrate that a chick's chemosensory preferences are changed as a result of experience with a stimulus before hatching and are suggestive of learning.

Uncertainty, learning and growth

The paper extends Blackburn and Galindev's (Economics Letters, Vol. 79 (2003), pp. 417-421) stochastic growth model in which productivity growth entails both external and internal learning behaviour with a constant relative risk aversion utility function and productivity shocks. Consequently, the relationship between long-term growth and short-term volatility depends not only on the relative importance of each learning mechanism but also on a parameter measuring individuals' attitude towards risk.

The Diffusion of Risks in Public Private Partnership Contracts

Purpose The UK government argues that the benefits of public private partnership (PPP) in delivering public infrastructure stem from: transferring risks to the private sector within a structure in which financiers put their own capital at risk; and, the performance based payment mechanism, reinforced by the due diligence requirements imposed by the lenders financing the projects (HM Treasury, 2010). Prior studies of risk in PPPs have investigated ‘what’ risks are allocated and to ‘whom’, that is to the public or the private sector. The purpose of this study is to examine ‘how’ and ‘why’ PPP risks are diffused by their financiers. Design/methodology/approach This study focuses on the financial structure of PPPs and on their financiers. Empirical evidence comes from interviews conducted with equity and debt financiers. Findings The findings show that the financial structure of the deals generates risk aversion in both debt and equity financiers and that the need to attract affordable finance leads to risk diffusion through a network of companies using various means that include contractual mitigation through insurance, performance support guarantees, interest rate swaps and inflation hedges. Because of the complexity this process generates, both procurers and suppliers need expensive expert advice. The risk aversion and diffusion and the consequent need for advice add cost to the projects impacting on the government’s economic argument for risk transfer. Limitations and implications The empirical work covers the private finance initiative (PFI) type of PPP arrangements and therefore the risk diffusion mechanisms may not be generalisable to other forms of PPP, especially those that do not involve the use of high leverage or private finance. Moreover, the scope of this research is limited to exploring the diffusion of risk in the private sector. Further research is needed on how risk is diffused in other settings and on the value for money implication of risk diffusion in PPP contracts. Originality/value The expectation inherent in PPP is that the private sector will better manage those risks allocated to it and because private capital is at risk, financiers will perform due diligence with the ultimate outcome that only viable projects will proceed. This paper presents empirical evidence that raises questions about these expectations. Key words: public private partnership, risk management, diffusion, private finance initiative, financiers

Novel bioassays to examine the host-finding ability of plant-parasitic nematodes

We present two novel bioassays to be used in the examination of plant-parasitic nematode host-finding ability. The host-finding 'pipette-bulb assay' was constructed from modelled Pasteur pipette bulbs and connecting barrels using parafilm fastenings. This assay examines the direction of second-stage juvenile (J2) migration in response to a host seedling, through a moistened sand substrate, which underlies terminal upward-facing 'seedling bulbs', one containing a host seedling in potting compost, the other with only potting compost. An equal watering regime through both upward-facing seedling bulbs creates a directional concentration gradient of host diffusate chemotactic factors. Positive chemotactic stimuli cause the J2 to orientate and migrate towards the host plant. We present validation data collected from assays of the root-knot nematode, Meloidogyne incognita, and the potato cyst nematode, Globodera pallida, which indicate a highly significant positive attraction of J2 of both species to respective host plants. This represents a simple, quick and inexpensive method of assessing host-finding behaviour in the laboratory. We consider that the pipette-bulb assay improves on previous host-finding/chemo-attraction assays through creating a more biologically relevant environment for experimental J2; analysis is quick and easy, allowing the straightforward interpretation of results. In addition, we have developed an 'agar trough' sensory assay variant which we believe can be used rapidly to ratify nematode responses to chemical gustatory or olfactory cues. This was constructed from a water agar substrate such that two counting wells were connected by a raised central trough, all flooded with water. Two small water agar plugs were dehydrated briefly in an oven and then hydrated in either an attractant, repellent or water control; these plugs were then placed in the terminal counting wells and subsequently leached the attractant or repellent to form a concentration gradient along the central trough, which contained the initial J2 innoculum. Our data show that both M. incognita and G. pallida J2 are positively attracted to host diffusates. In addition, they displayed a strong repulsion in response to 1 M NaCl2. J2 of M. incognita displayed a mild aversion to a non-host oak root diffusate, whereas G. pallida J2 displayed a strong aversion to the same non-host diffusate; neither species responded to a compost leachate. We believe that the agar trough assay improves on previous methods by facilitating rapid diffusion of attractant or repellents. Both of the aforementioned assays were designed as tools to assess the impact of RNAi-based reverse genetics screens for gene targets involved in chemosensory orientation.

Individual and couple decision behavior under risk: evidence on the dynamics of power balance

This article reports results of an experiment designed to analyze the link between risky decisions made by couples and risky decisions made separately by each spouse. We estimate both the spouses and the couples' degrees of risk aversion, we assess how the risk preferences of the two spouses aggregate when they make risky decisions, and we shed light on the dynamics of the decision process that takes place when couples make risky decisions. We find that, far from being fixed, the balance of power within the household is malleable. In most couples, men have, initially, more decision-making power than women but women who ultimately implement the joint decisions gain more and more power over the course of decision making.

Family caregivers' ideal expectations of Canada's Compassionate Care Benefit

We present the findings of 57 interviews conducted in 2007-2008 with Canadians who have cared for a dying family member to examine their ideal expectations of the Compassionate Care Benefit (CCB) - a social programme providing job security and income support for workers caring for a dying person. Our aims are to (1) appreciate how intended users and other family caregivers view the programme's very nature; (2) identify programme challenges and improvements that emerge from considering family caregivers' ideal expectations; and (3) contribute to a larger evaluative study designed to make policy-relevant recommendations for CCB improvement. Review of transcripts across three respondent groups reveals four categories of ideal expectations: (1) eligibility, (2) informational, (3) timing and (4) financial. Ideal expectations were typically derived from respondents' experiences of care-giving, their knowledge of the programme and, for some, of applying for and/or receiving the CCB. Findings reveal that there are gaps between respondents' ideal expectations and their experienced realities. Such gaps may lead to disappointment being experienced by those who believe they should be eligible for the programme but are not, or should be entitled to receive some form of support that is not presently available. This analysis plays an important role in identifying potential changes for the CCB that may better support family caregivers, in that the ideal expectations serve as a starting point for articulating desirable programme amendments. This analysis also has wider relevance. For jurisdictions looking to create new social programmes to support caregivers based upon labour policy strategies and legislation, this analysis identifies considerations that should be made at the outset of development. For jurisdictions that already have employment-based caregiver support programmes, this analysis demonstrates that programme challenges may not always be met through legislative changes alone but also through measures such as increasing awareness. © 2011 Blackwell Publishing Ltd.

The Art of Refusal: The Experiences of Grant Makers and Grant Seekers

This research project explores the communications’ experiences and practices of
selected grant making and grant seeking organisations, at the point of grant refusal. It was funded by the Charities Aid Foundation, and undertaken through collaboration with the Association of Charitable Foundations (ACF).
The research context is the enhanced competition for funding in which many grant seeking organisations experience the disappointment of refusal; whilst grant makers also face multiple pressures, in responding to grant seekers’ needs. This is an operating environment in which subsequent organisational learning appears demanding.
The aims of the research were to:
- Increase understanding of the communications demands, challenges and
opportunities in giving, receiving and sharing news of grant refusal
- Identify opportunities for organisational learning in these situations, for grant
makers and grant seekers
- Contribute to future practice improvement and development, by drawing on
the reported experiences and practices of participating respondents.

The research focuses on private, formal grant makers (foundations and trusts); and their grant seeking organisational constituencies. It excludes study of public grant makers’ grant refusal processes and those of individuals making personal gifts, direct businesses’ grant making, and grant making by community foundations and by other operating and fundraising charities. A staged research process began in 2008, and field research completed in 2009/2011.

Swift and Conversational Culture

Swift often noted his aversion to coffee-house conversation and to tavern talk, to gossip and company, and to being buried in Dublin in the years of his Deanship. Yet the popular myth of a morose, unsociable Swift belies both his engagement with various literary and political clubs in his early career and his participation in collaborative and experimental poetic games in his Dublin circles. This essay considers Swift’s involvement with three clubs in London (the Saturday Club, the Brothers’ Club, and the Scriblerians) and his writings on a number of fictional clubs (the Athenian Society, the Calves-Head Club, and a putative Society for the correction of the English language). While Swift wrote very little of his experience of actual clubs, the latter three, in addition to the Scriblerian Club as an imagined, rather than actual clubs, resulted in a number of defining poems and works in his career. When Swift settled in Dublin, poetry written and exchanged in a number of sociable circles characterised much of his published verse and gave glimpses of the circles and informal clubs which he formed among friends there. Although these poems are often dismissed as ‘trifles’, the essay argues that the poems are crucial for our understandings of ‘conversational culture’ or sociability in Swift’s Dublin.

Risk-aware Planning in BDI Agents

The ability of an autonomous agent to select rational actions is vital in enabling it to achieve its goals. To do so effectively in a high-stakes setting, the agent must be capable of considering the risk and potential reward of both immediate and future actions. In this paper we provide a novel method for calculating risk alongside utility in online planning algorithms. We integrate such a risk-aware planner with a BDI agent, allowing us to build agents that can set their risk aversion levels dynamically based on their changing beliefs about the environment. To guide the design of a risk-aware agent we propose a number of principles which such an agent should adhere to and show how our proposed framework satisfies these principles. Finally, we evaluate our approach and demonstrate that a dynamically risk-averse agent is capable of achieving a higher success rate than an agent that ignores risk, while obtaining a higher utility than an agent with a static risk attitude.