Thinplate Splines on the Sphere

In this paper we give explicit closed forms for the semi-reproducing kernels associated with thinplate spline interpolation on the sphere. Polyharmonic or thinplate splines for ${\mathbb R}^d$ were introduced by Duchon and have become a widely used tool in myriad applications. The analogues for ${\mathbb S}^{d-1}$ are the thin plate splines for the sphere. The topic was first discussed by Wahba in the early 1980's, for the ${\mathbb S}^2$ case. Wahba presented the associated semi-reproducing kernels as infinite series. These semi-reproducing kernels play a central role in expressions for the solution of the associated spline interpolation and smoothing problems. The main aims of the current paper are to give a recurrence for the semi-reproducing kernels, and also to use the recurrence to obtain explicit closed form expressions for many of these kernels. The closed form expressions will in many cases be significantly faster to evaluate than the series expansions. This will enhance the practicality of using these thinplate splines for the sphere in computations

The Benefits and Beneficiaries of "Public" Investment in Herbicide Use Research and Development

The allocation of benefits from research and development of new herbicide uses is dependent on patent status. The agricultural chemical industry will preferentially invest in herbicide R&D that increases the use of on-patent herbicides from which a company can capture a price premium. The distribution of benefits from increased use of on-patent herbicide will alter over time, with grain growers benefiting at the expense of agrichemical companies once the patent expires. Public sector investment in herbicide R&D may also benefit the agrichemical industry. The size and allocation of the benefits from R&D into on-patent herbicides is analyzed using economic surplus techniques. Two case studies are examined. One involves research into the choice and application of herbicide for new wheat varieties. The second case study involves returns from R&D investment in research into an alternative for the commonly used off-patent herbicide trifluralin. The results from the case studies show that herbicide patent status may not have important implications for "public" R&D investment decisions.Research and Development/Tech Change/Emerging Technologies, Q16, Q18, Q28,

Effective information and the influence of an extension event on perceptions and adoption

Perceptions are known to play an important role in the innovation adoption decision. Once influential perceptions have been identified, there is the potential for information to influence adoption by changing these perceptions. In this paper, the influence of an extension workshop targeting grain growers’ perceptions known to be associated with the adoption of integrated weed management and herbicide resistance management has been measured using regression analysis. Consistent with a Bayesian learning framework, the greatest influence on grower perceptions and intended adoption behaviour was observed where information could be delivered with a high degree of certainty and validity.Crop Production/Industries, Farm Management,

Promoting Student Engagement: Using Community Service-Learning Projects in Undergraduate Psychology

In this article, we present a novel way to integrate psychological theories and research methods by engaging undergraduate psychology students in service-learning projects. Our goal for the course was to bring to life theories and research methods that students often regard as academic rather than practical. We describe the different projects conducted with several community partners over the course of seven years. Students reported high satisfaction with the course as compared to similar courses that do not have a service-learning component. Additionally, students performed better (as measured by final grades) in the course that had a service-learning component. We discuss why service-learning had an impact on students and the benefits it provides for both students and faculty