12,201 research outputs found
Potential demand for hedging by Australian wheat producers
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
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
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
Inversion of polarimetric data from eclipsing binaries
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&
Changing Lead into Gold: Examining Agency Attempts to Use the Clean Water Act to Solve Ecosystem Degradation Issues
The Top Triangle Moose
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
Effect of undergraduate research programs on retention of Hispanic students
The Hispanic population in the United States has been increasing, which is affecting the number of Hispanic student population in the higher education. In spite of the rapid increase of Hispanic student population, little empirical research has been conducted on the Hispanic student’s college success. This study investigated the effect of participating in holistic undergraduate research programs on retention outcome of Hispanic students at The University of New Mexico. UNM is a public Hispanic-Serving Institution where 47.3 percent of undergraduate students are Hispanic in 2016.
The Vincent Tinto’s theory of student departure and the five critical factors of retention developed by Demetrious and Schmitz-Sciborski were used as the framework of the research model. The predictor variables included demographic characteristics, academic attributes, and research participation, and the dependent variable was the retention outcome. Propensity score matching was used to remove the concern of multicollinearity. The retention outcomes of two groups, Hispanic students who participated in research programs and who did not participate, were compared. The results indicated that research participation had a statistically significant positive effect on student’s retention outcome
And Now, Ladies and Gentlemen, Miss Judy Garland
Judy Garland has always been known for her standout role as “Dorothy” in The Wizard of Oz, but her life had many more trials than the character who sang about happy little bluebirds flying beyond the rainbow. She experienced not only successes like Oz, but also becoming known worldwide for her ability to capture an audience. She was more than an actress or a singer, she was a performer. Her need to be loved by an audience not only made it love her, but also had repercussions to her mental health. Despite many obstacles, Judy was persistent and determined to reach her audience
Minimum target prices for production of direct acting antivirals and associated diagnostics to combat Hepatitis C Virus
Combinations of direct-acting antivirals (DAAs) can cure hepatitis C virus (HCV) in the majority of treatment-naïve patients. Mass treatment programs to cure HCV in developing countries are only feasible if the costs of treatment and laboratory diagnostics are very low. This analysis aimed to estimate minimum costs of DAA treatment and associated diagnostic monitoring. Clinical trials of HCV DAAs were reviewed to identify combinations with consistently high rates of sustained virological response across hepatitis C genotypes. For each DAA, molecular structures, doses, treatment duration, and components of retrosynthesis were used to estimate costs of large-scale, generic production. Manufacturing costs per gram of DAA were based upon treating at least 5 million patients per year and a 40% margin for formulation. Costs of diagnostic support were estimated based on published minimum prices of genotyping, HCV antigen tests plus full blood count/clinical chemistry tests. Predicted minimum costs for 12-week courses of combination DAAs with the most consistent efficacy results were: US152 for sofosbuvir+ribavirin; US115 for MK-8742+MK-5172. Diagnostic testing costs were estimated at US34 for two HCV antigen tests and US171-360 per person without genotyping or US$261-450 per person with genotyping. These cost estimates assume that existing large-scale treatment programs can be established. (Hepatology 2015;61:1174–1182
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