On-Farm Benchmarking: How to Do It and How to Do It Better

Benchmarking is the practice of establishing the relative performance of a business or enterprise against an appropriate standard, generally industry standards derived from a survey of farms. The Policy Commission into the Future of Farming and Food (2002) highlighted a need to spread and improve benchmarking on farms. The requirements of effective benchmarking are illustrated in a ten step framework. The ten steps illustrate the range of expertise and resources a manager requires before being able to justify allocating resources to benchmarking. A comparison of alternative farm surveys and methodologies used to collect, analyse and report industry standards illustrates the difficulties farmers can have in identifying appropriate, robust and accurate industry standards. It is concluded that there needs to be a thorough rationalisation of farm surveys and agreement on methodologies to make benchmarking more effective and more efficient.benchmarking, comparative analysis, processes, industry standards, methodology, techniques, Farm Management,

Uptake of Sexed Semen by UK Suckler Beef Producers

Dairy farmers have been able to use sexed semen from dairy breeds to pre-determine the sex of calves since 2000, sexed semen from beef bulls is not currently commercially available, but is expected within 2 years. A survey of a stratified random sample of suckler cow farmers is used to identify the potential uptake of sexed semen when it becomes available using a logistic limited dependent variable model to identify different characteristics between farmers who intend to use sexed semen and those who do not. Herd size, the perception of the quality of bulls used to produce sexed semen, anticipated problems using AI, concern over conception rates, the cost and profitability of using sexed semen and herd replacement policy are found to be the major factors that will influence uptake. The relative importance of each constraint is shown, and approaches to reduce these constraints discussed.herd replacements, sexed semen, suckler beef production, subsidies, technical innovation, Livestock Production/Industries,

Mathematical modelling of contact dermatitis from nickel and chromium

Dermal exposure to metal allergens can lead to irritant (ICD) and allergic contact dermatitis (ACD). In this paper we present a mathematical model of the absorption of metal ions, hexavalent chromium and nickel, into the viable epidermis and compare the localised irritant and T-lymphocyte (T-cell) mediated immune responses. The model accounts for the spatial-temporal variation of skin health, extra and intracellular allergen concentrations, innate immune cells, T-cells, cytokine signalling and lymph node activity up to about 6 days after contact with these metals; repair processes associated with withdrawal of exposure to both metals is not considered in the current model, being assumed secondary during the initial phases of exposure. Simulations of the resulting system of PDEs are studied in one-dimension, i.e. across skin depth, and three-dimensional scenarios with the aim of comparing the responses to the two ions in the cases of first contact (no T-cells initially present) and second contact (T-cells initially present). The results show that on continuous contact, chromium ions elicit stronger skin inflammation, but for nickel, subsequent re-exposure stimulates stronger responses due to an accumulation of cytotoxic T-cell mediated responses which characterise ACD. Furthermore, the surface area of contact to these metals has little effect on the speed of response, whilst sensitivity is predicted to increase with the thickness of skin. The modelling approach is generic and should be applicable to describe contact dermatitis from a wide range of allergens

Signal and System Approximation from General Measurements

In this paper we analyze the behavior of system approximation processes for stable linear time-invariant (LTI) systems and signals in the Paley-Wiener space PW_\pi^1. We consider approximation processes, where the input signal is not directly used to generate the system output, but instead a sequence of numbers is used that is generated from the input signal by measurement functionals. We consider classical sampling which corresponds to a pointwise evaluation of the signal, as well as several more general measurement functionals. We show that a stable system approximation is not possible for pointwise sampling, because there exist signals and systems such that the approximation process diverges. This remains true even with oversampling. However, if more general measurement functionals are considered, a stable approximation is possible if oversampling is used. Further, we show that without oversampling we have divergence for a large class of practically relevant measurement procedures.Comment: This paper will be published as part of the book "New Perspectives on Approximation and Sampling Theory - Festschrift in honor of Paul Butzer's 85th birthday" in the Applied and Numerical Harmonic Analysis Series, Birkhauser (Springer-Verlag). Parts of this work have been presented at the IEEE International Conference on Acoustics, Speech, and Signal Processing 2014 (ICASSP 2014