13,520 research outputs found

    Potential demand for hedging by Australian wheat producers

    Get PDF
    The potential for hedging Australian wheat with the new Sydney Futures Exchange wheat contract is examined using a theoretical hedging model parametised from previous studies. The optimal hedging ratio for an `average' wheat farmer was found to be zero under reasonable assumptions about transaction costs and based on previously published measures of risk aversion. The estimated optimal hedging ratios were found by simulation to be quite sensitive to assumptions about the degree of risk aversion. If farmers are significantly more risk averse than is currently believed, then there is likely to be an active interest in the new futures market.Crop Production/Industries, Marketing, Risk and Uncertainty,

    The ethics of sociocultural risk research

    Get PDF
    In socio-cultural risk research, an epistemological tension often follows if real hazards in the world are juxtaposed against the essentially socially constructed nature of all risk. In this editorial, we consider how this paradox is manifest at a practical level in a number of ethical dilemmas for the risk researcher. (1) In terms of strategies for seeking informed consent, and for addressing the power inequalities involved in interpretative and analytical work, researchers can find themselves pushing at the boundaries of standard understandings of ethical practices and ways of engaging informants in their studies. (2) Impact on participants is another key area of concern, since the subject matter on which data are collected in risk research may be a source of uncertainty, anxiety or unwanted self knowledge. (3) Risk researchers also face the possibility of institutional repercussions of raising risk issues with people who usually normalize the risks, thereby stimulating distrust in the institutions or organizations with formal responsibilities for risk management. There are no simple formulae to guide the researcher in dealing with such ethical issues and paradoxes. It is important, though, to recognize their specificity in risk studies, including the ambiguous status of questions about vulnerability since judgements about 'who is vulnerable' and 'in what ways' are themselves influenced by the situational framings and understandings of participants and researchers

    An error analysis of probabilistic fibre tracking methods: average curves optimization

    Get PDF
    Fibre tractography using diffusion tensor imaging is a promising method for estimating the pathways of white matter tracts in the human brain. The success of fibre tracking methods ultimately depends upon the accuracy of the fibre tracking algorithms and the quality of the data. Uncertainty and its representation have an important role to play in fibre tractography methods to infer useful information from real world noisy diffusion weighted data. Probabilistic fibre tracking approaches have received considerable interest recently for resolving orientational uncertainties. In this study, an average curves approach was used to investigate the impact of SNR and tensor field geometry on the accuracy of three different types of probabilistic tracking algorithms. The accuracy was assessed using simulated data and a range of tract geometries. The average curves representations were employed to represent the optimal fibre path of probabilistic tracking curves. The results are compared with streamline tracking on both simulated and in vivo data

    Parasitism of Early Instar Jack Pine Budworm (Lepidoptera: Tortricidae) by Apanteles Spp. (Hymenoptera: Braconidae) and Glypta Fumiferanae (Hymenoptera: Ichneumonidae)

    Get PDF
    Glypta fumiferanae and two species of Apanteles parasitized 1st-4th instar jack pine bud worm (Choristoneura pinus). Apparent parasitism of budworm in four Michigan populations ranged from 10.6 to 30.9% for A. fumiferanae, 4.3-16.4% for A. morrisi, and 2.1-9.1 % for G.fumiferanae. A. morrisi probably parasitized 3rd-4th instar jack pine bud worm. Based on the results obtained, it is suggested that sampling overwintering budworm larvae is appropriate for estimating apparent parasitism by A. fumiferanae and G. fumiferanae. Sampling budworm larvae at ca. 500 degree-days (base 8.9°C) is appropriate for estimating apparent parasitism by A. morrisi

    Inversion of polarimetric data from eclipsing binaries

    Get PDF
    We describe a method for determining the limb polarization and limb darkening of stars in eclipsing binary systems, by inverting photometric and polarimetric light curves. Because of the ill-conditioning of the problem, we use the Backus-Gilbert method to control the resolution and stability of the recovered solution, and to make quantitative estimates of the maximum accuracy possible. Using this method we confirm that the limb polarization can indeed be recovered, and demonstrate this with simulated data, thus determining the level of observational accuracy required to achieve a given accuracy of reconstruction. This allows us to set out an optimal observational strategy, and to critcally assess the claimed detection of limb polarization in the Algol system. The use of polarization in stars has been proposed as a diagnostic tool in microlensing surveys by Simmons et al. (1995), and we discuss the extension of this work to the case of microlensing of extended sources.Comment: 10pp, 5 figures. To appear in A&

    The Top Triangle Moose

    Full text link
    We introduce a deconstructed model that incorporates both Higgsless and top-color mechanisms. The model alleviates the typical tension in Higgsless models between obtaining the correct top quark mass and keeping delta-rho small. It does so by singling out the top quark mass generation as arising from a Yukawa coupling to an effective top-Higgs which develops a small vacuum expectation value, while electroweak symmetry breaking results largely from a Higgsless mechanism. As a result, the heavy partners of the SM fermions can be light enough to be seen at the LHC.Comment: To appear in proceedings of SCGT09, Nagoya, Japan. 5 page

    Financial Literacy in High School Education

    Get PDF
    Personal finance has become increasingly complicated in the past thirty years due to globalization and financial engineering. Americans are faced with new financial products and decisions, and many do not have the knowledge or expertise to successfully manage their finances. Financial literacy is especially low among young adults. Individual states have responded by introducing a personal finance course into the high school curriculum. This course may be an elective or a requirement for graduation. This study begins to examine personal finance curriculum in high schools and the effect such coursework has on overall financial literacy when students reach college
    corecore