What can research deliver for organic farming?

The research needs of any applied subject are always influenced by three major groups of criteria. These are the economic/political, the societal/ethical and the technical/scientific. This is especially the case for Organic Farming which explicitly sets out to present a positively value based approach to agriculture, an activity, which has commonly become dominated by the commercial economics of an industrial society. To maintain this ethical stance Organic Farming must challenge some of the tenets of conventional economics and politics and must work within the particular societal context. Its scientific needs are then driven either by the need to increase its role in terms of market share or the need to achieve its aims more effectively in respect of product quality and/or delivery of environmental goods. In this paper I examine the current opportunities for Organic Farming in relation to the present state of farming economics and the current expectations of society, considering both food production and the delivery of environmental services which are paid from the public purse, e.g. via the Common Agricultural Policy (CAP). I use these criteria to analyse what are the current primary research needs in relation to the science and ethical base of Organic Agriculture

Telerobot task planning and reasoning: Introduction to JPL artificial intelligence research

A view of the capabilities and areas of artificial intelligence research which are required for autonomous space telerobotics extending through the year 2000 is given. In the coming years, JPL will be conducting directed research to achieve these capabilities, as well as drawing heavily on collaborative efforts conducted with other research laboratories

Pattern classes and priority queues

When a set of permutations comprising a pattern class C is submitted as input to a priority queue the resulting output is again a pattern class C'. The basis of C' is determined for pattern classes C whose basis elements have length 3, and is finite in these cases. An example is given of a class C with basis 2431 for which C is not finitely based

Permutation Classes of Polynomial Growth

A pattern class is a set of permutations closed under the formation of subpermutations. Such classes can be characterised as those permutations not involving a particular set of forbidden permutations. A simple collection of necessary and sufficient conditions on sets of forbidden permutations which ensure that the associated pattern class is of polynomial growth is determined. A catalogue of all such sets of forbidden permutations having three or fewer elements is provided together with bounds on the degrees of the associated enumerating polynomials.Comment: 17 pages, 4 figure

Municipal commonage and implications for land reform: A profile of commonage users in Philippolis, Free State, South Africa

This paper reports on a survey of municipal commonage users, which was undertaken in Philippolis in the southern Free State, in May 2005. The survey showed that a significant number of commonage users are committed to their farming enterprises, as shown by five proxy indicators: Their readiness to plough their income into their farming enterprises; their sale of livestock; their desire for more land, and their willingness to pay rental to secure such land; their desire to farm on their own; and their desire to own their own land. The paper reflects on the significance of commonage in the context of the South African government’s land reform policy, and argues that commonage can transcend survivalist or subsistence production, and can be used as a “stepping stone” for emergent farmers to access their own land parcels. Finally, the paper argues that, if commonage is to become a key part in a “step-up” strategy of land reform, then appropriately sized land parcels should be made available for commonage users, to enable them to “exit” from commonage use and invest in smallholdings or small farms.Land Economics/Use,

Economic Doctrines and Approaches to Climate Change Policy

In climate change, as in all policy issues, economic philosophy has a significant influence on how people view both the problems and the solutions. For the first time, ITIF surveys four dominant schools of economic thought and analyzes how adherents approach policy options for climate change and energy policy. With climate change and major energy legislation stalled, maybe it is time to put aside fixed philosophical notions and take a practical look on ways to address climate change in an economically feasible way. The report reviews the principles and goals of each economic doctrine, and offers a critique of the advantages and limitations of each doctrine's contribution to addressing the challenge of climate change.Innovation; Economics; Climate Change; Public Policy

Isomorphisms between pattern classes

Isomorphisms p between pattern classes A and B are considered. It is shown that, if p is not a symmetry of the entire set of permutations, then, to within symmetry, A is a subset of one a small set of pattern classes whose structure, including their enumeration, is determined.Comment: 11 page

Examination of Silica Sol-Gels and Aerogels Containing Silver Nanoparticles and 4-Mercaptobenzoic Acid Using Surface-Enhanced Raman Spectroscopy

Sol-gels and aero-gels containing silver nanoparticles have been investigated for use as substrates in surface-enhanced Raman spectroscopy (SERS). 4-Mercaptobenzoic acid (4-MBA) was chosen as the target molecule in this study, as it has been well-characterized using SERS. The orientation of the 4-MBA at different coverages in gels, and at differing concentrations of silver colloid, has not been well studied. For both base and acid-catalyzed sol-gels, xerogels, and aerogels, the concentration of 4-MBA was varied with a constant silver colloid concentration in the silica gels and the effects were measured with SERS. The effect of varying silver colloid concentration against a constant 4-MBA concentration was also investigated. The results of each process were compared

The enumeration of permutations avoiding 2143 and 4231

We enumerate the pattern class Av(2143, 4231) and completely describe its permutations. The main tools are simple permutations and monotone grid classes

Multiplicative renormalizability and quark propagator

The renormalized Dyson-Schwinger equation for the quark propagator is studied, in Landau gauge, in a novel truncation which preserves multiplicative renormalizability. The renormalization constants are formally eliminated from the integral equations, and the running coupling explicitly enters the kernels of the new equations. To construct a truncation which preserves multiplicative renormalizability, and reproduces the correct leading order perturbative behavior, non-trivial cancellations involving the full quark-gluon vertex are assumed in the quark self-energy loop. A model for the running coupling is introduced, with infrared fixed point in agreement with previous Dyson-Schwinger studies of the gauge sector, and with correct logarithmic tail. Dynamical chiral symmetry breaking is investigated, and the generated quark mass is of the order of the extension of the infrared plateau of the coupling, and about three times larger than in the Abelian approximation, which violates multiplicative renormalizability. The generated scale is of the right size for hadronic phenomenology, without requiring an infrared enhancement of the running coupling.Comment: 17 pages; minor corrections, comparison to lattice results added; accepted for publication in Phys. Rev.