Travel time reliability: a review of late time valuations, elasticities and demand impacts in the passenger rail market in Great Britain

This paper provides an extensive review and reconciliation of British and European evidence relating to the value of, and demand responses to, rail reliability. In particular, we compare the elasticities implied by stated preference valuations of late time with directly estimated lateness elasticities. We find that the implied lateness elasticities are substantially greater than those directly estimated. A possible explanation for this is that lateness has been over-valued, but more sobering explanations would be to suggest that, whilst rail travellers dislike unreliability, they may be unwilling or unable to reduce their rail travel in response to experiences of poor performance, or else conventional economic approaches to deducing elasticities are not appropriate. The findings have been used to update the recommendations of the UK rail industry’s Passenger Demand Forecasting Handbook

The value of travel time: random utility versus random valuation

This paper identifies, relates and compares two popular modelling approaches to estimate the value of travel time changes. The first (random utility [RU]) assumes that the random component of the model relates to the difference between the utilities of travel options; the second (random valuation [RV]) assumes that it relates to the difference between the value of travel time and a suggested valuation threshold. This paper gives details of the theoretical relationship between the two approaches and compares them empirically at several levels of model sophistication. Datasets from two national studies (the UK and Denmark) are employed. The results show a consistent superiority of the RV approach and a systematic gap in the value of travel time between approaches. A similar pattern across models is found in both countries. This raises questions about the validity of results using the RU approach. The analysis has direct implications for both researchers and policy-makers

The Politics of Service Delivery Reform

This article identifies the leaders, the supporters and the resisters of public service reform. It adopts a principal–agent framework, comparing reality with an ‘ideal’ situation in which citizens are the principals over political policy-makers as their agents, and policy-makers are the principals over public service officials as their agents. Reform in most developing countries is complicated by an additional set of external actors — international financial institutions and donors. In practice, international agencies and core government officials usually act as the ‘principals’ in the determination of reforms. The analysis identifies the interests involved in reform, indicating how the balance between them is affected by institutional and sectoral factors. Organizational reforms, particularly in the social sectors, present greater difficulties than first generation economic policy reforms

Radiative corrections to neutral pion-pair production

We calculate the one-photon loop radiative corrections to the neutral pion-pair photoproduction process $\pi^-\gamma \to \pi^-\pi^0\pi^0$. At leading order this reaction is governed by the chiral pion-pion interaction. Since the chiral $\pi^+\pi^-\to\pi^0\pi^0$ contact-vertex depends only on the final-state invariant-mass it factors out of all photon-loop diagrams. We give analytical expressions for the multiplicative correction factor $R\sim \alpha/2\pi$ arising from eight classes of contributing one-photon loop diagrams. An electromagnetic counterterm has to be included in order to cancel the ultraviolet divergences generated by the photon-loops. Infrared finiteness of the virtual radiative corrections is achieved (in the standard way) by including soft photon radiation below an energy cut-off $\lambda$. The radiative corrections to the total cross section vary between $+2\%$ and $-2\%$ for center-of-mass energies from threshold up to $7m_\pi$. The finite part of the electromagnetic counterterm gives an additional constant contribution of about $1\%$, however with a large uncertainty.Comment: 10 pages, 6 figures, submitted to Eur. Phys. J.

Empirical parameterization of the K+- -> pi+- pi0 pi0 decay Dalitz plot

As first observed by the NA48/2 experiment at the CERN SPS, the \p0p0 invariant mass (M00) distribution from \kcnn decay shows a cusp-like anomaly at M00=2m+, where m+ is the charged pion mass. An analysis to extract the pi pi scattering lengths in the isospin I=0 and I=2 states, a0 and a2, respectively, has been recently reported. In the present work the Dalitz plot of this decay is fitted to a new empirical parameterization suitable for practical purposes, such as Monte Carlo simulations of K+- -> pi+- pi0 pi0 decays.Comment: 9 pages, 3 figures

Radiative corrections in K --> 3 pi decays

We investigate radiative corrections to K --> 3 pi decays. In particular, we extend the non-relativistic framework developed recently to include real and virtual photons and show that, in a well-defined power counting scheme, the results reproduce corrections obtained in the relativistic calculation. Real photons are included exactly, beyond the soft-photon approximation, and we compare the result with the latter. The singularities generated by pionium near threshold are investigated, and a region is identified where standard perturbation theory in the fine structure constant alpha may be applied. We expect that the formulae provided allow one to extract S-wave pi pi scattering lengths from the cusp effect in these decays with high precision.Comment: 57 pages, 17 figure

AutoSNPdb: an annotated single nucleotide polymorphism database for crop plants

Single nucleotide polymorphisms (SNPs) may be considered the ultimate genetic marker as they represent the finest resolution of a DNA sequence (a single nucleotide), are generally abundant in populations and have a low mutation rate. Analysis of assembled EST sequence data provides a cost-effective means to identify large numbers of SNPs associated with functional genes. We have developed an integrated SNP discovery pipeline, which identifies SNPs from assembled EST sequences. The results are maintained in a custom relational database along with EST source and annotation information. The current database hosts data for the important crops rice, barley and Brassica. Users may rapidly identify polymorphic sequences of interest through BLAST sequence comparison, keyword searches of annotations derived from UniRef90 and GenBank comparisons, GO annotations or in genes corresponding to syntenic regions of reference genomes. In addition, SNPs between specific varieties may be identified for targeted mapping and association studies. SNPs are viewed using a user-friendly graphical interface. The database is freely accessible at http://autosnpdb.qfab.org.au/

The di-iron RIC protein (YtfE) of Escherichia coli interacts with the DNA-binding protein from starved cells (Dps) to diminish RIC-protein-mediated redox stress

The RIC (Repair of Iron Clusters) protein of Escherichia coli is a di-iron hemerythrin-like protein that has a proposed function in repairing stress-damaged iron-sulphur clusters. In this work, we performed a Bacterial Two Hybrid screening to search for RIC-protein interaction partners in E. coli. As a result, the DNA-binding protein from starved cells (Dps) was identified and its potential interaction with RIC was tested by BACTH, Bimolecular-Fluorescence-Complementation and pull-down assays. Using the activity of two Fe-S-containing enzyme as indicators of cellular Fe-S cluster damage, we observed that strains with single deletions of ric or dps have significantly lower aconitase and fumarase activities. In contrast, the double ric dps mutant strain displayed no loss of aconitase and fumarase activity with respect to the wild type. Additionally, while complementation of the ric dps double mutant with ric led to a severe loss of aconitase activity, this effect was no longer observed when a gene encoding a di-iron site variant of the RIC protein was employed. The dps mutant exhibited a large increase in ROS levels, but this increase was eliminated when ric was also inactivated. Absence of other iron storage proteins, or of peroxidase and catalases, had no impact on RIC-mediated redox stress induction. Hence, we show that RIC interacts with Dps in a manner that serves to protect E. coli from RIC-protein-induced ROS

The isospin symmetry breaking effects in Ke4K_{e4} decays

The Fermi-Watson theorem is generalized to the case of two coupled channels with different masses and applied to final state interaction in $K_{e4}$ decays. The impact of considered effect on the phase of the $\pi\pi$ scattering is estimated and shown that it can be crucial for scattering lengths extraction from experimental data on $K_{e4}$ decays