There is nothing like an oat

The items reports on first year trials in of the “Quoats” project. It’s well known that oats are generally a good fit in organic rotations and the “Quoats” project – Harnessing new technologies for sustainable oat production and utilisation – aims to make them even better. This five year (2009 – 2014) research project, led by IBERS, Aberystwyth University, brings together a wide range of organisations in the supply chain, from breeders to end-users, to improve the quality and performance of oats. As part of the project, ORC is carrying out field trials to assess the suitability of new oat lines for organic management systems, with particular emphasis on nutrient use efficiency. Eight varieties are being trialled at Wakelyns Agroforestry, Suffolk, including some naked oats, i.e. hull-less oats. The paper reports some first results

TUGS – The tactile user guidance system

The Electronic System and Information Technology Research Group at Brunel University has designed a multifaceted navigation system for blind and visually impaired pedestrians. The primary operation of the system mimics the advantages of an informed sighted guide by using Global Positioning Systems and remote (sighted on the user) video cameras as navigational sensors. The information generated is streamed to a central control centre. This allows the system to operate in a fully automatic or operator assisted mode dependent on the users requirements. Initially the system used an audio link to transfer information to the user, however this has proved problematic. Clear unimpeded access to ambient sound is vital for visually impaired and blind pedestrians, both for efficient wayfinding and safety. Any system which has a continuing dialogue with the user, for example, navigational instructions received through an audio link, interferes with the users ability to process ambient sounds. To solve this problem a novel Tactile User Guidance System (TUGS) with vibrating actuators, has been designed and experimentally tested. In this paper we present the design and experimental verification of TUGS with both visually impaired and sighted users. Although we have taken the visually impaired user as the ‘worst case scenario’ a practical ability to transfer information through the tactile sense has considerable value to other groups who may find themselves in restricted or overloaded visual or audio situations. These groups include; front line responders in the emergency services, railroad workers, pilots and remote vehicle operators

Self Similar Spherical Collapse Revisited: a Comparison between Gas and Dark Matter Dynamics

We reconsider the collapse of cosmic structures in an Einstein-de Sitter Universe, using the self similar initial conditions of Fillmore & Goldreich (1984). We first derive a new approximation to describe the dark matter dynamics in spherical geometry, that we refer to the "fluid approach". This method enables us to recover the self-similarity solutions of Fillmore & Goldreich for dark matter. We derive also new self-similarity solutions for the gas. We thus compare directly gas and dark matter dynamics, focusing on the differences due to their different dimensionalities in velocity space. This work may have interesting consequences for gas and dark matter distributions in large galaxy clusters, allowing to explain why the total mass profile is always steeper than the X-ray gas profile. We discuss also the shape of the dark matter density profile found in N-body simulations in terms of a change of dimensionality in the dark matter velocity space. The stable clustering hypothesis has been finally considered in the light of this analytical approach.Comment: 14 pages, 2 figures, accepted for publication in The Astrophysical Journa

Hydra: An Adaptive--Mesh Implementation of PPPM--SPH

We present an implementation of Smoothed Particle Hydrodynamics (SPH) in an adaptive-mesh PPPM algorithm. The code evolves a mixture of purely gravitational particles and gas particles. The code retains the desirable properties of previous PPPM--SPH implementations; speed under light clustering, naturally periodic boundary conditions and accurate pairwise forces. Under heavy clustering the cycle time of the new code is only 2--3 times slower than for a uniform particle distribution, overcoming the principal disadvantage of previous implementations\dash a dramatic loss of efficiency as clustering develops. A 1000 step simulation with 65,536 particles (half dark, half gas) runs in one day on a Sun Sparc10 workstation. The choice of time integration scheme is investigated in detail. A simple single-step Predictor--Corrector type integrator is most efficient. A method for generating an initial distribution of particles by allowing a a uniform temperature gas of SPH particles to relax within a periodic box is presented. The average SPH density that results varies by $\sim\pm1.3$\%. We present a modified form of the Layzer--Irvine equation which includes the thermal contribution of the gas together with radiative cooling. Tests of sound waves, shocks, spherical infall and collapse are presented. Appropriate timestep constraints sufficient to ensure both energy and entropy conservation are discussed. A cluster simulation, repeating Thomas andComment: 29 pp, uuencoded Postscrip

Developing modern multifunctional agroforestry systems for sustainable intensification

Agroforestry is a land-use system that integrates trees and shrubs with crops and/or livestock production. It has been identified by the International Assessment of Agricultural Knowledge, Science and Technology for Development (IAASTD, 2008) as a ‘win-win’ approach that balances the production of commodities (food, feed, fuel, fibre, etc.) with non-commodity outputs such as environmental protection and cultural and landscape amenities. This paper will review the potential of agroforestry as part of a multifunctional working landscape in temperate regions, and will consider management and policy implications of widespread adoption of this form of land-use