Rail Privatisation – How Is It Going?

The 1993 Railways Act provided for the privatisation of British Rail in the form of franchising of passenger services and outright sale of all other parts of the business. The privatisation was unusually complex, with the existing single organisation being divided into more than 80 separate companies, the intention being to create competition not just in the form of competing train operating companies, but also for the supply of services such as rolling stock and track maintenance, wherever possible. The aim of this paper is to review events since the process of rail privatisation in Britain really started in April 1994. It is based partly on the publications of the relevant bodies and the technical press but partly on conversations with those in the industry. It is divided into five sections, looking in turn at Railtrack and the ROSCOs, the passenger franchising process, the freight sector and other businesses before seeking to draw some overall conclusions

Zero modes of the Dirac operator in three dimensions

We investigate zero modes of the Dirac operator coupled to an Abelian gauge field in three dimensions. We find that the existence of a certain class of zero modes is related to a specific topological property precisely when the requirement of finite Chern--Simons action is imposed.Comment: 13 pages, 6 figures, uses the macro psbox.tex, replaced by a revised version to be published in Phys. Rev. D. The section on the Seiberg-Witten equations, which contained a sign error, has been removed. This removal leads to further issues which will appear in a future publicatio

Railway Reform in China.

The purpose of this working paper is to consider the current situation of Chinese Railways, the progress of reforms to date, and possible future developments. The first section describes the current problems of Chinese Railways, as a vast organisation subject to strong central control, facing enormous and rapidly growing demands which it is unable to satisfy. The progress of reform in Chinese Railways to date, and in particular the Economic Contract Responsibility System instituted in the late 1980's and the development of joint venture companies to build new lines, are then described. In the following section the key reform models found in other countries - deregulation and privatisation of vertically integrated regional companies; separation of infrastructure from operations with open access andlor franchising competitors; or reorganisation on the basis of business sectors - are then described. None is fully suitable for China, but it is suggested that a combination of sectorisation, more commercial independence, further development of joint public/private partnerships and more contracting out, is the most likely way forward

The Case for High Speed Rail

There is currently a wave of high speed rail proposals sweeping through Europe, amounting to some 7000 route kilometres of new construction and 8000 of upgraded track and costing of the order of 58 billion ecu (in 1985 prices). There is therefore an urgent need for a careful assessment of the costs and benefits, both of the network as a whole and of the individual component parts of it. The principal benefits of high speed rail are taken to be the revenue, traffic and time savings it generates; relief of congestion , accidents and environmental effects of other modes of transport and its alleged local and regional development benefits. Clearly many of these benefits depend on how far it really does divert traffic from these modes as opposed to generating totally new trips. At the same time, high speed rail schemes have significant environmental costs. Evidence on all of these issues is examined, and it is concluded that the evidence for environmental and development benefits is limited, although in the former case in particular much depends on the exact circumstances. Given the wide variety of options in terms of speeds and mix of upgrading versus new construction, careful appraisal is very important, and a traditional transport cost-benefit analysis and environmental impact assessment appear well equipped to capture the main costs and benefits. The conclusion is that there is likely to be a good case for a core network linking the major cities of Western Europe in the middle distance range, but beyond that, upgrading of existing infrastructure and development of new technology may provide a more cost-effective solution

The twistor geometry of three-qubit entanglement

A geometrical description of three qubit entanglement is given. A part of the transformations corresponding to stochastic local operations and classical communication on the qubits is regarded as a gauge degree of freedom. Entangled states can be represented by the points of the Klein quadric ${\cal Q}$ a space known from twistor theory. It is shown that three-qubit invariants are vanishing on special subspaces of ${\cal Q}$. An invariant vanishing for the $GHZ$ class is proposed. A geometric interpretation of the canonical decomposition and the inequality for distributed entanglement is also given.Comment: 4 pages RevTeX

Phase Dynamics of Two Entangled Qubits

We make a geometric study of the phases acquired by a general pure bipartite two level system after a cyclic unitary evolution. The geometric representation of the two particle Hilbert space makes use of Hopf fibrations. It allows for a simple description of the dynamics of the entangled state's phase during the whole evolution. The global phase after a cyclic evolution is always an entire multiple of $\pi$ for all bipartite states, a result that does not depend on the degree of entanglement. There are three different types of phases combining themselves so as to result in the $n \pi$ global phase. They can be identified as dynamical, geometrical and topological. Each one of them can be easily identified using the presented geometric description. The interplay between them depends on the initial state and on its trajectory and the results obtained are shown to be in connection to those on mixed states phases.Comment: 9 figures, slightly different version from the accepted on

A multinomial quadrivariate D-vine copula mixed model for meta-analysis of diagnostic studies in the presence of non-evaluable subjects

Diagnostic test accuracy studies observe the result of a gold standard procedure that defines the presence or absence of a disease and the result of a diagnostic test. They typically report the number of true positives, false positives, true negatives and false negatives. However, diagnostic test outcomes can also be either non-evaluable positives or non-evaluable negatives. We propose a novel model for the meta-analysis of diagnostic studies in the presence of non-evaluable outcomes, which assumes independent multinomial distributions for the true and non-evaluable positives, and, the true and non-evaluable negatives, conditional on the latent sensitivity, specificity, probability of non-evaluable positives and probability of non-evaluable negatives in each study. For the random effects distribution of the latent proportions, we employ a drawable vine copula that can successively model the dependence in the joint tails. Our methodology is demonstrated with an extensive simulation study and applied to data from diagnostic accuracy studies of coronary computed tomography angiography for the detection of coronary artery disease. The comparison of our method with the existing approaches yields findings in the real data application that change the current conclusions

Hydrographic Study of Peirce Island Wastewater Treatment Plant Effluent in the Piscataqua River of Portsmouth, New Hampshire: Report of Findings from the December 10 – 14, 2012 Study Period

In order to assist the New Hampshire Department of Environmental Services (NHDES) evaluate the impact of treated wastewater effluent from Peirce Island Wastewater Treatment Plant (WWTP) to the Lower Piscataqua River and Portsmouth Harbor a hydrographic dye study was conducted in December 2012 in Portsmouth, NH. Eight (8) shellfish cages with American oysters (Crassostrea virginica) and blue mussels (Mytilus edulis) were deployed both upstream and downstream of the Peirce Island WWTP in the Piscataqua River, Little Harbor, and the entrance of Little Bay. Eight (8) mini CTDs that monitor conductivity/salinity, temperature, and depth, and six (6) moored fluorometers, which measure dye tagged effluent from the Peirce Island WWTP were attached to the subsurface cages. A fifty (50) gallon mixture of Rhodamine WT dye and distilled water was injected into WWTP on December 11, 2012 for a half tidal cycle (approximately 12.4 hours). Additionally, boat tracking fluorometers connected with a mobile geographic information system (GIS) were used to measure dye levels on the surface in situ and in real time. Microbiological analyses of fecal coliform (FC), male-specific coliphage (MSC), Norovirus (NoV) genogroup I (GI) and genogroup II (GII), and Adenovirus (AdV) were conducted on WWTP influent and effluent composite samples collected with automated samplers to determine the WWTP efficiency in reducing indicator bacteria and viruses. Microbiological sampling and testing of oysters and mussels from the eight (8) sentinel cages was conducted to assess the impact of WWTP effluent on shellfish growing areas and growing area classifications. Prior to conducting the study, the assumption was that the FDA’s recommended minimum dilution of 1000:1was not applicable in this situation because the recommended dilution is based on a WWTP having at least secondary treatment. The microbiological findings in shellfish samples, wastewater samples from the Peirce Island WWTP, and the results of the dye study, confirm that a minimum of 1,000:1 dilution with respect to Peirce Island WWTP is currently not applicable for this WWTP. The FDA and NHDES recommend continued MSC testing of wastewater samples from the WWTP before and after the WWTP upgrade. The FDA and NHDES recommend a future field study after the WWTP upgrade in order to delineate the 1,000:1 dilution zone