Electrochemical Sensing of Dopamine using a Dodecylsulfate Doped Polypyrrole Film

A polymer-modified electrode was fabricated by the electropolymerisation of pyrrole from an ethanol solution using sodium dodecylsulfate as a dopant. The modified electrode is a highly sensitive electrochemical sensor for dopamine with a limit of detection measured as 3.8 x 10-8 mol dm-3. The sensor did not sense the common interferant ascorbic acid showing a single redox peak for dopamine in the presence of excess ascorbic acid

A Bayesian Surrogate Model for Rapid Time Series Analysis and Application to Exoplanet Observations

We present a Bayesian surrogate model for the analysis of periodic or quasi-periodic time series data. We describe a computationally efficient implementation that enables Bayesian model comparison. We apply this model to simulated and real exoplanet observations. We discuss the results and demonstrate some of the challenges for applying our surrogate model to realistic exoplanet data sets. In particular, we find that analyses of real world data should pay careful attention to the effects of uneven spacing of observations and the choice of prior for the "jitter" parameter.Comment: 25 pages, 4 figures, accepted to Bayesian Analysis , special issue for Ninth Valencia International Conference on Bayesian Statistic

Adoption of Plantain within New Zealand Farming Systems

In New Zealand, plantain has been incorporated into the pasture forage base in three ways: as a short-term pure crop; as a major component in “herb mixes” that include clovers and chicory; and as a minor component in perennial grass-based swards. All types are typically grazed in-situ. Given the incentive to optimise the plantain proportion in livestock diet to mitigate nitrogen losses and the observed lack of persistence in grass-dominant pasture over time, there is a need to use various pasture types strategically across a farm system to ensure a long-term sustainable contribution of plantain to feed intake. The inclusion of plantain in the forage base should be relatively straightforward since farmers are already familiar with establishing and managing forage crops and mixed-species pastures. However, there are still technical questions to answer and incentives to implement before we can achieve the region-wide adoption necessary to result in a measurable impact on water quality. The Tararua District, on the east coast of the North Island of New Zealand, represents a useful case study of adoption in a strong dairy farming region. Some underpinning elements for successful adoption were in place: 1) national agronomic experience in using a plantain cultivar released in 1996; and 2) regulatory push in terms of reducing N leaching losses on farms. However, other initiatives were required to see meaningful progress: provision of data from local dairy farm systems, focused on the impact on forage supply/quality; a targeted extension program by a trusted sector leader agency (DairyNZ); individual farmer risk-taking and leadership in establishing and managing new crops and pastures. After three years, awareness is well embedded in the rural community and approximately 30% of dairy farms within the district have started to use plantain

Insights from the 2006 Disease Management Colloquium

This roundtable discussion emanates from the presentations given and issues raised at the 2006 Disease Management Colloquium, which was held May 10–12, 2006 in Philadelphia, Pennsylvania