Combining Agri-Environment Schemes For Environmental And Financial Benefit - Tir Gofal And Organic Farming

Peter Davies farms 750 acres in the Vale of Glamorgan. He has a suckler herd and sheep, with arable crops for sale off the farm and for livestock feed. The farm began conversion in 1999 and most of it will finish in 2001. It was accepted into the Tir Gofal whole farm agri-environment scheme in 2000. In this interview with Will John he explains how the two schemes work together. He has researched and planned the changes carefully and expects his farm enterprise to benefit in the long term

Complex hyperbolic free groups with many parabolic elements

We consider in this work representations of the of the fundamental group of the 3-punctured sphere in ${\rm PU}(2,1)$ such that the boundary loops are mapped to ${\rm PU}(2,1)$. We provide a system of coordinates on the corresponding representation variety, and analyse more specifically those representations corresponding to subgroups of $(3,3,\infty)$-groups. In particular we prove that it is possible to construct representations of the free group of rank two \la a,b\ra in ${\rm PU}(2,1)$ for which $a$, $b$, $ab$, $ab^{-1}$, $ab^2$, $a^2b$ and $[a,b]$ all are mapped to parabolics.Comment: 21 pages, 11 figure

The impact of contract duration on the cost of cash retention

Cash retention is a common means of protecting an employer from a contractor's insolvency as well as ensuring that contractors finish the work that they start. Similarly, contractors withhold part of payments due to their sub-contractors. Larger contracts tend to be subjected to smaller rates of retention. By calculating the cost of retention as an amount per year of a contract, it is shown that retention is far more expensive for firms whose work consists of short contracts. The extra cost is multiplied when the final payment is delayed, as it often is for those whose work takes place at the beginning of a project. This may explain why it is that main contractors are a lot less interested than sub-contractors in alternatives to cash retention, such as retention bond

Construction subcontracts: for what we are about to receive

This paper is from a study on specialist and trade contracting in the construction industry. The research was commissioned by CIRIA and undertaken by the University of Reading in conjunction with Sir Alexander Gibb & Partners Ltd. The purpose of the work was to provide guidance for effective and equitable practice in the management of projects where much of the work is executed, and possibly designed, by specialist and trade contractors (STCs). As part of this study, a preliminary investigation into the nature and origins of specialist contracting was undertaken, in conjunction with a survey of the problems confronting STCs. This paper presents that phase of the project

Would Freeing Up World Trade Reduce Poverty and Inequality? The Vexed Role of Agricultural Distortions

Trade policy reforms in recent decades have sharply reduced the distortions that were harming agriculture in developing countries, yet global trade in farm products continues to be far more distorted than trade in nonfarm goods. Those distortions reduce some forms of poverty and inequality but worsen others, so the net effects are unclear without empirical modeling. This paper summarizes a series of new economy-wide global and national empirical studies that focus on the net effects of the remaining distortions to world merchandise trade on poverty and inequality globally and in various developing countries. The global LINKAGE model results suggest that removing those remaining distortions would reduce international inequality, largely by boosting net farm incomes and raising real wages for unskilled workers in developing countries, and would reduce the number of poor people worldwide by 3 percent. The analysis based on the Global Trade Analysis Project (GTAP) model for a sample of 15 countries, and ten stand-alone national case studies, all point to larger reductions in poverty, especially if only the non-poor are subjected to increased income taxation to compensate for the loss of trade tax revenue.Poverty, income inequality, price distortions, farm trade policy

Would freeing up world trade reduce poverty and inequality ? the vexed role of agricultural distortions

Trade policy reforms in recent decades have sharply reduced the distortions that were harming agriculture in developing countries, yet global trade in farm products continues to be far more distorted than trade in nonfarm goods. Those distortions reduce some forms of poverty and inequality but worsen others, so the net effects are unclear without empirical modeling. This paper summarizes a series of new economy-wide global and national empirical studies that focus on the net effects of the remaining distortions to world merchandise trade on poverty and inequality globally and in various developing countries. The global LINKAGE model results suggest that removing those remaining distortions would reduce international inequality, largely by boosting net farm incomes and raising real wages for unskilled workers in developing countries, and would reduce the number of poor people worldwide by 3 percent. The analysis based on the Global Trade Analysis Project model for a sample of 15 countries, and nine stand-alone national case studies, all point to larger reductions in poverty, especially if only the non-poor are subjected to increased income taxation to compensate for the loss of trade tax revenue.Rural Poverty Reduction,Economic Theory&Research,Emerging Markets,Trade Policy,Achieving Shared Growth

Fourier analysis of luminosity-dependent galaxy clustering

We extend the Fourier transform based method for the analysis of galaxy redshift surveys of Feldman, Kaiser & Peacock (1994: FKP) to model luminosity-dependent clustering. In a magnitude limited survey, galaxies at high redshift are more luminous on average than galaxies at low redshift. Galaxy clustering is observed to increase with luminosity, so the inferred density field is effectively multiplied by an increasing function of radius. This has the potential to distort the shape of the recovered power spectrum. In this paper we present an extension of the FKP analysis method to incorporate this effect, and present revised optimal weights to maximize the precision of such an analysis. The method is tested and its accuracy assessed using mock catalogues of the 2-degree field galaxy redshift survey (2dFGRS). We also show that the systematic effect caused by ignoring luminosity-dependent bias was negligible for the initial analysis of the 2dFGRS of Percival et al. (2001). However, future surveys, sensitive to larger scales, or covering a wider range of galaxy luminosities will benefit from this refined method.Comment: 9 pages, 4 figures, accepted for publication in MNRA

Do the laws of physics prohibit counterfactual communication?

It has been conjectured that counterfactual communication is impossible, even for post-selected quantum particles. We strongly challenge this by proposing exactly such a counterfactual scheme where---unambiguously---none of Alice's photons that make it has been to Bob. We demonstrate counterfactuality theoretically and experimentally by means of weak measurements, as well as conceptually using consistent histories. Importantly, the accuracy of Alice learning Bob's bit can be made arbitrarily close to unity with no trace left by Bob on Alice's photon.Comment: Experiment conducted in the lab, showing no weak trace from Bob at either D0 or D1. 5 pages, 5 figure

On the effects of self- and cross-phase modulation on photon purity for four-wave mixing photon-pair sources

We consider the effect of self-phase modulation and cross-phase modulation on the joint spectral amplitude of photon pairs generated by spontaneous four-wave mixing. In particular, the purity of a heralded photon from a pair is considered, in the context of schemes that aim to maximise the purity and minimise correlation in the joint spectral amplitude using birefringent phase-matching and short pump pulses. We find that non-linear phase modulation effects will be detrimental, and will limit the quantum interference visibility that can be achieved at a given generation rate. An approximate expression for the joint spectral amplitude with phase modulation is found by considering the group velocity walk-off between each photon and the pump, but neglecting the group-velocity dispersion at each wavelength. The group-velocity dispersion can also be included with a numerical calculation, and it is shown that it only has a small effect on the purity for the realistic parameters considered.Comment: 11 pages, 10 figure