Quarantine Risk Analysis

Australia’s quarantine policy is based on the concept of manageable risk, which is underpinned by quarantine risk analysis, which this article examines with particular reference to recommendations of the 1996 Australian Quarantine Review. Quarantine risk assessment addresses disease concerns associated with any particular proposed import and may also require detailed examination of possible economic and environmental effects. The degree of quantification varies, and more quantitative approaches may be either deterministic or stochastic. Assessments consider both the probability of an event occurring and its consequences, including the direct economic effect of any introduction of an exotic disease.International Relations/Trade,

Australian quarantine post the Nairn Review

The Commonwealth government has accepted the basic tenets of the report of the Australian Quarantine Review (the ‘Nairn Review’), except for the recommendations to establish a statutory authority. Australia will maintain its existing high standards of quarantine and enhance activities such as community awareness, manageable risk (based on science), protection of Australia’s unique environment, external input to policy formulation, and recognition of the continuum of quarantine (pre‐border, border and post‐border). Greater emphasis will be given to improved consultation in risk analysis, increased monitoring for pests and diseases, and enhanced national preparedness and response capacity (especially for plants and aquatic animals).International Relations/Trade,

Optimal experiment design revisited: fair, precise and minimal tomography

Given an experimental set-up and a fixed number of measurements, how should one take data in order to optimally reconstruct the state of a quantum system? The problem of optimal experiment design (OED) for quantum state tomography was first broached by Kosut et al. [arXiv:quant-ph/0411093v1]. Here we provide efficient numerical algorithms for finding the optimal design, and analytic results for the case of 'minimal tomography'. We also introduce the average OED, which is independent of the state to be reconstructed, and the optimal design for tomography (ODT), which minimizes tomographic bias. We find that these two designs are generally similar. Monte-Carlo simulations confirm the utility of our results for qubits. Finally, we adapt our approach to deal with constrained techniques such as maximum likelihood estimation. We find that these are less amenable to optimization than cruder reconstruction methods, such as linear inversion.Comment: 16 pages, 7 figure

Large-Alphabet Time-Frequency Entangled Quantum Key Distribution by means of Time-to-Frequency Conversion

We introduce a novel time-frequency quantum key distribution (TFQKD) scheme based on photon pairs entangled in these two conjugate degrees of freedom. The scheme uses spectral detection and phase modulation to enable measurements in the temporal basis by means of time-to-frequency conversion. This allows large-alphabet encoding to be implemented with realistic components. A general security analysis for TFQKD with binned measurements reveals a close connection with finite-dimensional QKD protocols and enables analysis of the effects of dark counts on the secure key size.Comment: 14 pages, 3 figures, submitte

The contested and contingent outcomes of Thatcherism in the UK

The death of Margaret Thatcher in April 2013 sparked a range of discussions and debates about the significance of her period in office and the political project to which she gave her name: Thatcherism. This article argues that Thatcherism is best understood as a symbolically important part of the emergence of first-phase neoliberalism. It engages with contemporary debates about Thatcherism among Marxist commentators and suggests that several apparently divergent positions can help us now reach a more useful analysis of Thatcherism’s short- and long-term outcomes for British political economy. The outcomes identified include: an initial crisis in the neoliberal project in the UK; the transformation of the party political system to be reflective of the politics of neoliberalism, rather than its contestation; long-term attempts at the inculcation of the neoliberal individual; de-industrialisation and financial sector dependence; and a fractured and partially unconscious working class. In all long-term outcomes, the contribution of Thatcherism is best understood as partial and largely negative, in that it cleared the way for a longer-term and more constructive attempt to embed neoliberal political economy. The paper concludes by suggesting that this analysis can inform current debates on the left of British politics about how to oppose and challenge the imposition of neoliberal discipline today

Strategies for enhancing quantum entanglement by local photon subtraction

Subtracting photons from a two-mode squeezed state is a well-known method to increase entanglement. We analyse different strategies of local photon subtraction from a two-mode squeezed state in terms of entanglement gain and success probability. We develop a general framework that incorporates imperfections and losses in all stages of the process: before, during, and after subtraction. By combining all three effects into a single efficiency parameter, we provide analytical and numerical results for subtraction strategies using photon-number-resolving and threshold detectors. We compare the entanglement gain afforded by symmetric and asymmetric subtraction scenarios across the two modes. For a given amount of loss, we identify an optimised set of parameters, such as initial squeezing and subtraction beam splitter transmissivity, that maximise the entanglement gain rate. We identify regimes for which asymmetric subtraction of different Fock states on the two modes outperforms symmetric strategies. In the lossless limit, subtracting a single photon from one mode always produces the highest entanglement gain rate. In the lossy case, the optimal strategy depends strongly on the losses on each mode individually, such that there is no general optimal strategy. Rather, taking losses on each mode as the only input parameters, we can identify the optimal subtraction strategy and required beam splitter transmissivities and initial squeezing parameter. Finally, we discuss the implications of our results for the distillation of continuous-variable quantum entanglement.Comment: 13 pages, 11 figures. Updated version for publicatio

Alternative approaches to tuberculosis treatment evaluation: the role of pragmatic trials

Clinical trials are sometimes classified as being explanatory or pragmatic, although they are rarely reported in that way. Explanatory trials may seek to investigate the efficacy of new treatments by imposing strict limitations on many aspects of trial design, including, for example, recruiting only those patients who are most likely to respond. In contrast, the objective of pragmatic trials is to assess whether treatments work in conditions more appropriate to routine practice. This dichotomy is, however, over-simplistic; there is usually a continuum, which is a consequence of there being many areas of trial design that can vary between the extremities of the explanatory and pragmatic approaches. The PRECIS (pragmatic-explanatory continuum indicator summary) wheel based on 10 domains, which include inclusion criteria, flexibility of delivery of the intervention and intensity of follow-up, has been proposed as a way of enabling researchers to assess the extent to which the trials they are designing could be considered explanatory or pragmatic. In this article, we consider how the PRECIS tool can be applied to trials of tuberculosis treatment. In view of the well-recognised delay in getting results from well-conducted clinical trials into practice, we would suggest that if more pragmatic trials were to be conducted, physicians would better understand the implications of the results for their own practice and be more ready to adopt new treatments

A physics-based life prediction methodology for thermal barrier coating systems

A novel mechanistic approach is proposed for the prediction of the life of thermal barrier coating (TBC) systems. The life prediction methodology is based on a criterion linked directly to the dominant failure mechanism. It relies on a statistical treatment of the TBC's morphological characteristics, non-destructive stress measurements and on a continuum mechanics framework to quantify the stresses that promote the nucleation and growth of microcracks within the TBC. The last of these accounts for the effects of TBC constituents' elasto-visco-plastic properties, the stiffening of the ceramic due to sintering and the oxidation at the interface between the thermally insulating yttria stabilized zirconia (YSZ) layer and the metallic bond coat. The mechanistic approach is used to investigate the effects on TBC life of the properties and morphology of the top YSZ coating, metallic low-pressure plasma sprayed bond coat and the thermally grown oxide. Its calibration is based on TBC damage inferred from non-destructive fluorescence measurements using piezo-spectroscopy and on the numerically predicted local TBC stresses responsible for the initiation of such damage. The potential applicability of the methodology to other types of TBC coatings and thermal loading conditions is also discussed