699 research outputs found
Simulation of quantum random walks using interference of classical field
We suggest a theoretical scheme for the simulation of quantum random walks on
a line using beam splitters, phase shifters and photodetectors. Our model
enables us to simulate a quantum random walk with use of the wave nature of
classical light fields. Furthermore, the proposed set-up allows the analysis of
the effects of decoherence. The transition from a pure mean photon-number
distribution to a classical one is studied varying the decoherence parameters.Comment: extensively revised version; title changed; to appear on Phys. Rev.
Human Clostridium difficile infection caused by a livestock-associated PCR ribotype 237 strain in Western Australia
Introduction:
Clostridium difficile infection (CDI) is a significant gastrointestinal disease in the developed world and increasingly recognised as a zoonotic infection. In North America and Europe, the PCR ribotype (RT) 078 strain of C. difficile is commonly found in production animals and as a cause of disease in humans although proof of transmission from animals is lacking. This strain is absent in Australian livestock. We report a case of human CDI caused by a strain of C. difficile belonging to known Australian livestock-associated RT 237.
Case presentation:
A young male was admitted for multiple trauma following a motor vehicle accident and placed on piperacillin/tazobactam for pneumonia. After 4 days of treatment, he developed symptoms of CDI, which was confirmed in the laboratory. His symptoms resolved after 6 days of intravenous metronidazole. The strain of C. difficile isolated was identified as RT 237, an unusual RT previously found in with several Western Australia piggeries.
Conclusion:
This case of CDI caused by an unusual livestock-associated C. difficile RT 237 supports the hypothesis of zoonotic transmission. The case highlights the potential of livestock to act as reservoir for C. difficile and the need for continued surveillance of CDI in both human and animal populations
Incipient Separation in Shock Wave Boundary Layer Interactions as Induced by Sharp Fin
The incipient separation induced by the shock wave turbulent boundary layer
interaction at the sharp fin is the subject of present study. Existing theories
for the prediction of incipient separation, such as those put forward by McCabe
(1966) and Dou and Deng (1992), can have thus far only predicting the direction
of surface streamline and tend to over-predict the incipient separation
condition based on the Stanbrook's criterion. In this paper, the incipient
separation is firstly predicted with Dou and Deng (1992)'s theory and then
compared with Lu and Settles (1990)' experimental data. The physical mechanism
of the incipient separation as induced by the shock wave/turbulent boundary
layer interactions at sharp fin is explained via the surface flow pattern
analysis. Furthermore, the reason for the observed discrepancy between the
predicted and experimental incipient separation conditions is clarified. It is
found that when the wall limiting streamlines behind the shock wave becomes\
aligning with one ray from the virtual origin as the strength of shock wave
increases, the incipient separation line is formed at which the wall limiting
streamline becomes perpendicular to the local pressure gradient. The formation
of this incipient separation line is the beginning of the separation process.
The effects of Reynolds number and the Mach number on incipient separation are
also discussed. Finally, a correlation for the correction of the incipient
separation angle as predicted by the theory is also given.Comment: 34 pages; 9 figure
Diffusion as mixing mechanism in granular materials
We present several numerical results on granular mixtures. In particular, we
examine the efficiency of diffusion as a mixing mechanism in these systems. The
collisions are inelastic and to compensate the energy loss, we thermalize the
grains by adding a random force. Starting with a segregated system, we show
that uniform agitation (heating) leads to a uniform mixture of grains of
different sizes. We define a characteristic mixing time, , and
study theoretically and numerically its dependence on other parameters like the
density. We examine a model for bidisperse systems for which we can calculate
some physical quantities. We also examine the effect of a temperature gradient
and demonstrate the appearance of an expected segregation.Comment: 15 eps figures, include
Quantum Anti-Zeno Effect
We demonstrate that near threshold decay processes may be accelerated by
repeated measurements. Examples include near threshold photodetachment of an
electron from a negative ion, and spontaneous emission in a cavity close to the
cutoff frequency, or in a photon band gap material.Comment: 4 pages, 3 figure
A method and tool for ‘cradle to grave’ embodied energy and carbon impacts of UK buildings in compliance with the new TC350 standards
As operational impacts from buildings are reduced, embodied impacts are increasing. However, the latter are seldom calculated in the UK; when they are, they tend to be calculated after the building has been constructed, or are underestimated by considering only the initial materials stage. In 2010, the UK Government recommended that a standard methodology for calculating embodied impacts of buildings be developed for early stage design decisions. This was followed in 2011–12 by the publication of the European TC350 standards defining the ‘cradle to grave’ impact of buildings and products through a process Life Cycle Analysis.
This paper describes a new whole life embodied carbon and energy of buildings (ECEB) tool, designed as a usable empirical-based approach for early stage design decisions for UK buildings. The tool complies where possible with the TC350 standards. Initial results for a simple masonry construction dwelling are given in terms of the percentage contribution of each life cycle stage. The main difficulty in obtaining these results is found to be the lack of data, and the paper suggests that the construction and manufacturing industries now have a responsibility to develop new data in order to support this task
Entanglement in bipartite generalized coherent states
Entanglement in a class of bipartite generalized coherent states is
discussed. It is shown that a positive parameter can be associated with the
bipartite generalized coherent states so that the states with equal value for
the parameter are of equal entanglement. It is shown that the maximum possible
entanglement of 1 bit is attained if the positive parameter equals .
The result that the entanglement is one bit when the relative phase between the
composing states is in bipartite coherent states is shown to be true for
the class of bipartite generalized coherent states considered.Comment: 10 pages, 4 figures; typos corrected and figures redrawn for better
clarit
Financial toxicity in adults with cancer: Adverse outcomes and noncompliance
Purpose Because of the escalating cost of cancer care coupled with high insurance deductibles, premiums, and uninsured populations, patients with cancer are affected by treatmentrelated financial harm, known as financial toxicity. The purpose of this study was to describe individuals reporting financial toxicity and to identify rates of and reasons for affordability-related treatment noncompliance. Methods From May 2010 to November 2015, adult patients (age $ 18 years) with cancer were identified from a Health Registry/Cancer Survivorship Cohort. Financial toxicity was defined as agreement with the phrase"You have to pay for more medical care than you can afford" from the Patient Satisfaction Questionnaire-18. Logistic regression and Fisher exact tests were used to compare groups. Results Of 1,988 participants, 524 (26%) reported financial toxicity. Patients reporting financial toxicity were more likely age 65 years or younger, female, nonwhite, non-English speaking, not married, less educated, and to have received a diagnosis more recently (all P,.001). Participants with financial toxicity were more likely to report noncompliance with medication, owing to inability to afford prescription drugs (relative risk [RR], 3.55; 95% CI, 2.53 to 4.98), and reported forgoing mental health care (RR, 3.89; 95% CI, 2.04 to 7.45), doctor's visits (RR, 2.98; 95% CI, 1.97 to 4.51), and medical tests (RR, 2.54; 95% CI, 1.49 to 4.34). The most endorsed reasons for delayed care were not having insurance coverage and being unable to afford household expenses. Conclusion More than25%of adultswith cancer reportedfinancial toxicity thatwas associatedwith an increased riskfor medicalnoncompliance.Financial toxicity remains a major issue in cancer care, and efforts are needed to ensure patients experiencing high levels offinancial toxicity are able to access recommended care
Women’s tenure security on collective lands: A conceptual framework
Within discussions of land and resource rights, there is growing attention to women’s rights, mostly in terms of household and individual rights to private property. This leaves unanswered questions about whether and how women’s land rights can be secured under collective tenure, upon which billions of people worldwide depend. There is an important gap in conceptual tools, empirical understanding, and policy recommendations on women’s land rights within collective tenure. To address this gap and lay the foundations for a sound body of empirical studies and appropriate policies, we develop a conceptual framework to improve our understanding of women’s land rights under collective tenure. We begin by discussing what secure tenure for women on collective lands would entail. We then present the conceptual framework for what factors would affect women’s tenure security, building on a framework for land tenure security that focuses on individual and household tenure. We give attention to particularities of rangelands, forests, and other types of lands as well as commonalities across types of collective lands. A key theme that emerges is that for women to have secure tenure under collective tenure, two dimensions must be in place. First, the collective (group) itself must have tenure security. Second, women must have secure rights within this collective. The latter requires us to consider the governance structures, how men and women access and control land, and the extent to which women have voice and power within the collective. More consistent analyses of collective tenure systems using the framework presented in this paper can help to identify which action resources are important for groups to secure rights to collective lands, and for women to advocate for their rights within the group
DrinkWise, enjoy responsibly: News frames, branding and alcohol
This article examines the communicative activities and press coverage of the alcohol industry-funded social-change organisation DrinkWise. Established in 2005, DrinkWise funds health research in universities, runs public health campaigns and engages in public relations activities. We use a framing analysis to examine the way DrinkWise frames problems, judgements and solutions related to alcohol consumption and policy. The aim of this analysis is to examine how journalistic practice legitimises DrinkWise and facilitates the organisation’s communicative activities. In addition, we consider how DrinkWise’s representation in the press works alongside the organisation’s array of communicative activities to facilitate the commercial objectives of the alcohol industry. We draw on the implications of this analysis to conceptualise how distinct forms of communicative work – such as academic research, policy-making, journalism and marketing, advertising and public relations – are interconnected
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