Entanglement Manipulation and Concentration

We introduce a simple, experimentally realisable, entanglement manipulation protocol for exploring mixed state entanglement. We show that for both non-maximally entangled pure, and mixed polarisation-entangled two qubit states, an increase in the degree of entanglement and purity, which we define as concentration, is achievable.Comment: Accepted as Rapid Communication PR

Response to requests for general practice out of hours: geographical analysis in north west England

The organisation of out of hours general practice (GP) in the UK has changed rapidly in recent years as practice based rotas and deputising services have given way to GP cooperatives in many areas. At the same time, the proportion of patients contacting an out of hours service who receive telephone advice only, rather than a face to face consultation, has risen substantially, although patients continue to express strong preferences for personal contact with a doctor out of hours. We examined the effect of the distance of the patient from the primary care centre on the doctor’s decision to see the patient face to face

Irreversible Investment and Optimal Fisheries Management: A Stochastic Analysis

In recent years, attention has been devoted to fishery management problems that arise because capital embodied in fishing fleets is often nonmalleable. having few if any alternative uses. This problem of irreversible investment was analyzed by Clark et al. (1979), using a deterministic model. In reality, however, most investment decisions must be made within an uncertain environment. This paper describes recent efforts to account for uncertainty in analyzing the problem of optimal fishery investment, where the uncertainty is caused by stochastic variability in the resource stock from year to year.Environmental Economics and Policy, International Development, Resource /Energy Economics and Policy, Risk and Uncertainty,

Whole-gear efficiency of a benthic survey trawl for flatfish

Whole-gear efficiency (the proportion of fish passing between the otter doors of a bottom trawl that are subsequently captured) was estimated from data collected during experiments to measure the herding efficiency of bridles and doors, the capture efficiency of the net, and the length of the bridles sufficiently close to the seafloor to elicit a herding response. The experiments were focused on four species of flatfish: arrowtooth flounder (Atheresthes stomias), flathead sole (Hippoglossoides elassodon), rex sole (Glyptocephalus zachirus), and Dover sole (Microstomus pacificus). Whole-gear efficiency varied with fish length and reached maximum values between 40% and 50% for arrowtooth flounder, flathead sole, and rex sole. For Dover sole, however, whole-gear efficiency declined from a maximum of 33% over the length range sampled. Such efficiency estimates can be used to determine catchability, which, in turn, can be used to improve the accuracy of stock assessment models when the time series of a survey is short

Teleportation using coupled oscillator states

We analyse the fidelity of teleportation protocols, as a function of resource entanglement, for three kinds of two mode oscillator states: states with fixed total photon number, number states entangled at a beam splitter, and the two-mode squeezed vacuum state. We define corresponding teleportation protocols for each case including phase noise to model degraded entanglement of each resource.Comment: 21 pages REVTeX, manuscript format, 7 figures postscript, many changes to pape

Disagreement between correlations of quantum mechanics and stochastic electrodynamics in the damped parametric oscillator

Intracavity and external third order correlations in the damped nondegenerate parametric oscillator are calculated for quantum mechanics and stochastic electrodynamics (SED), a semiclassical theory. The two theories yield greatly different results, with the correlations of quantum mechanics being cubic in the system's nonlinear coupling constant and those of SED being linear in the same constant. In particular, differences between the two theories are present in at least a mesoscopic regime. They also exist when realistic damping is included. Such differences illustrate distinctions between quantum mechanics and a hidden variable theory for continuous variables.Comment: accepted by PR

Quantum Computation with Coherent States, Linear Interactions and Superposed Resources

We show that quantum computation circuits with coherent states as the logical qubits can be constructed using very simple linear networks, conditional measurements and coherent superposition resource states

Cost effectiveness of a community based exercise programme in over 65 year olds: cluster randomised trial

OBJECTIVE: To assess the cost effectiveness of a community based exercise programme as a population wide public health intervention for older adults. DESIGN: Pragmatic, cluster randomised community intervention trial. Setting: 12 general practices in Sheffield; four randomly selected as intervention populations, and eight as control populations. PARTICIPANTS: All those aged 65 and over in the least active four fifths of the population responding to a baseline survey. There were 2283 eligible participants from intervention practices and 4137 from control practices. INTERVENTION: Eligible subjects were invited to free locally held exercise classes, made available for two years. MAIN OUTCOME MEASURES: All cause and exercise related cause specific mortality and hospital service use at two years, and health status assessed at baseline, one, and two years using the SF-36. A cost utility analysis was also undertaken. RESULTS: Twenty six per cent of the eligible intervention practice population attended one or more exercise sessions. There were no significant differences in mortality rates, survival times, or admissions. After adjusting for baseline characteristics, patients in intervention practices had a lower decline in health status, although this reached significance only for the energy dimension and two composite scores (p,0.05). The incremental average QALY gain of 0.011 per person in the intervention population resulted in an incremental cost per QALY ratio of J17 174 (95% CI =J8300 to J87 120). CONCLUSIONS: Despite a low level of adherence to the exercise programme, there were significant gains in health related quality of life. The programme was more cost effective than many existing medical interventions, and would be practical for primary care commissioning agencies to implement

Pathways out of poverty for Zimbabwe.

An IES Conference Paper on the socio-economic situation among Zimbabwe's children during the years 1990- 2008.Children in Zimbabwe suffered badly during the long socioeconomic crisis in Zimbabwe from about 1990 to 2008. During its peak, from 2002 to 2008, health, nutrition, education and other social indicators in Zimbabwe reached extremely low levels. Despite recent improvements in the situation of Zimbabwe’s children, many of the effects of the socioeconomic crisis on them are long-term, even permanent. Pre-natal and early childhood malnutrition, orphan-hood, and disrupted education have all created lasting damage. The Government of Zimbabwe faces several challenges in re-establishing social services for children. The country’s fiscal capacity is not what it once was, yet public expectations for improvements are high. In such a situation of high expectations, it is tempting to tiy to do everything at once. Suggestions are made for focusing on re-establishing basic services, with an emphasis on building quality, equity, coverage and participation.The research presented in this publication is a result of a project funded by Canada’s International Development Research Centre (www.idrc.ca