EFRC Cereal Variety and Mixture Trials 2001 – Preliminary Results

Of 7 winter wheats grown at 3 sites in southern England in 2001, the highest yielding was the soft wheat Claire; the breadmaking varieties Hereward, Shamrock and Spark did well. Of the feed wheats, Aardvark outyielded Deben. Of various variety mixtures tried, Aardvark/Claire/Deben was highest yielding. When seed was saved from the 2000 harvest of Hereward/Malacca/Shamrock and grown in 2001, it outyielded the first generation mixture, suggesting that some adaptation had occurred, relative composition changing in response to the local conditions. Winter oats and triticale were trialled at one site in Berkshire. The triticales Ego and Fidelio performed well, as did the winter oat Kingfisher. The oat mixture Ego/Fidelio/Taurus outyielded the mean of its component varieties. The triticale mixture Ego/Fidelio/Taurus showed adaptation from 2000 to 2001

Identification of Stochastic Wiener Systems using Indirect Inference

We study identification of stochastic Wiener dynamic systems using so-called indirect inference. The main idea is to first fit an auxiliary model to the observed data and then in a second step, often by simulation, fit a more structured model to the estimated auxiliary model. This two-step procedure can be used when the direct maximum-likelihood estimate is difficult or intractable to compute. One such example is the identification of stochastic Wiener systems, i.e.,~linear dynamic systems with process noise where the output is measured using a non-linear sensor with additive measurement noise. It is in principle possible to evaluate the log-likelihood cost function using numerical integration, but the corresponding optimization problem can be quite intricate. This motivates studying consistent, but sub-optimal, identification methods for stochastic Wiener systems. We will consider indirect inference using the best linear approximation as an auxiliary model. We show that the key to obtain a reliable estimate is to use uncertainty weighting when fitting the stochastic Wiener model to the auxiliary model estimate. The main technical contribution of this paper is the corresponding asymptotic variance analysis. A numerical evaluation is presented based on a first-order finite impulse response system with a cubic non-linearity, for which certain illustrative analytic properties are derived.Comment: The 17th IFAC Symposium on System Identification, SYSID 2015, Beijing, China, October 19-21, 201

A review of knowledge of the potential impacts of GMOs on organic agriculture

The organic movement believes that organic agriculture, by its nature, cannot involve the use of genetically modified organisms (GMOs). This has been incorporated into EU regulations which state that there is no place in organic agriculture for GMOs. The aim in this review is to consider the ways in which the use of GMOs in agriculture in the UK and internationally might impact on organic farming. It does not address the controversy about the rights or wrongs of GMO’s per se. The subjects covered are based on a set of questions raised at the beginning of the study. The review is based primarily on evidence from peer-reviewed literature. The report is based on a number of themes, as follows: • Fate of DNA in soil • Fate of DNA in livestock feed and possible impact of GM feed • Fate of DNA in slurry, manure, compost and mulch • Impact of herbicide tolerant crops • Impact of pest and disease resistant crops • Safety of promoters • DNA transfer in pollen and seeds • Horizontal gene transfer • Impact of scale The report’s Executive Summary includes summaries of the findings on each of these themes

Reweighted nuclear norm regularization: A SPARSEVA approach

The aim of this paper is to develop a method to estimate high order FIR and ARX models using least squares with re-weighted nuclear norm regularization. Typically, the choice of the tuning parameter in the reweighting scheme is computationally expensive, hence we propose the use of the SPARSEVA (SPARSe Estimation based on a VAlidation criterion) framework to overcome this problem. Furthermore, we suggest the use of the prediction error criterion (PEC) to select the tuning parameter in the SPARSEVA algorithm. Numerical examples demonstrate the veracity of this method which has close ties with the traditional technique of cross validation, but using much less computations.Comment: This paper is accepted and will be published in The Proceedings of the 17th IFAC Symposium on System Identification (SYSID 2015), Beijing, China, 201

What Lies Beneath: Treatment of Canvas-backed Pennsylvania Coal Mining Maps for Digitization

An ongoing program to preserve approximately seven hundred oversized, canvas-backed, coal mining maps from the CONSOL Energy Mining Map Collection was initiated by the University of Pittsburgh (Pitt) in 2007, supported by funding from the United States Department of the Interior Office of Surface Mining and Reclamation (OSM) and the Pennsylvania Department of Environmental Protection (PA-DEP). The main goal of this project is to stabilize and clean the mining maps for digitization at the OSM National Mine Map Repository (NMMR) located in Pittsburgh, Pennsylvania. The digitized data of the underground mines will be incorporated into Geographical Information Systems relative to mine safety, land reclamation, current mining operations, and new development

The long-term agronomic performance of organic stockless rotations

This report was presented at the UK Organic Research 2002 Conference. Two long-term experiments were established with the aim of evaluating the agronomic and economic performance of organic stockless rotations. In total, four different rotations were evaluated at two sites in the south (Elm Farm Research Centre) and east (ADAS Terrington) of England. All of the rotations included either a one or two-year red clover green manure crop to provide nitrogen for subsequent crops and it was found that this was sufficient to support three or four years of arable cropping. Over a period of eleven years at EFRC and five years at ADAS Terrington, there was no evidence of a decline in crop yield, although there were significant year-to-year variations. Crop yields were generally equivalent to or greater than average organic yields. Levels of soil available P and K was maintained at both sites at non-limiting levels. Pest and diseases were not problematic, but perennial weeds posed the most significant problem

An analysis of the SPARSEVA estimate for the finite sample data case

In this paper, we develop an upper bound for the SPARSEVA (SPARSe Estimation based on a VAlidation criterion) estimation error in a general scheme, i.e., when the cost function is strongly convex and the regularized norm is decomposable for a pair of subspaces. We show how this general bound can be applied to a sparse regression problem to obtain an upper bound for the traditional SPARSEVA problem. Numerical results are used to illustrate the effectiveness of the suggested bound

Advocacy 20 years on from Hampel: is it time we revisited the postgraduate teaching of advocacy?

This paper seeks to discuss the teaching of advocacy as a discipline with specific reference to the way in which advocacy is taught on the Bar Professional Training Course in England and Wales. The Advocacy Training Council favours the Hampel Method of teaching advocacy first developed more than 20 years ago in Australia. The paper seeks to review the use of the Hampel Method by offering a critique of behaviourist learning theory from a constructivist standpoint and putting forward alternative teaching techniques which are in harmony with the principles of constructivism, experiential learning and productive failure. We conclude that the teaching of advocacy can be improved and that greater scholarship is needed in this important area to ensure students are taught using the best techniques