1,016 research outputs found
Decline in effectiveness of antenatal corticosteroids with time to birth : real or artefact?
The effectiveness of antenatal corticosteroids to prevent neonatal lung disease in women at risk of preterm birth was established by systematic reviews. In addition, subgroup analyses suggested that treatment was most effective in babies born one to seven days after administration. This belief led to widespread use of repeated courses of corticosteroids in women who did not deliver within a week or two of initial treatment. However, the notion that effectiveness declines after seven days may be incorrect, as the analyses that it is based on are unreliable. Here, we discuss the methodological problems of these analyses and their relevance to current randomised controlled trials of repeated versus single courses
The One Loop Effective Super-Potential and Non-Holomorphicity
We calculate the Kahlerian and the lowest order non-Kahlerian contributions
to the one loop effective superpotential using super-Feynman graphs in the
massless Wess-Zumino Model, the massive Wess-Zumino Model and N=1, U(1) gauge
theory. We also calculate the Kahlerian term in Yang-Mills Theory for a general
gauge group. Using this latter result we find the one loop Kahlerian
contribution for N=2 Yang-Mills Theory in terms of N=1 superfields and we show
that it can only come from non-holomorphic contributions to the N=2 effective
potential.Comment: LaTeX, 10 pages, 7 figures, uses bezier.sty and ifthen.sty. First
amendment. The results are extended to include the Kahlerian term for a
general renormalisable N=1 supersymmetric theory, containing Wess-Zumino and
Yang-Mills multiplets with a cubic superpotential. One reference has been
changed and one has been added. Second amendment. One acknowledgment has been
altered in the `note added in proof
Time reversal and exchange symmetries of unitary gate capacities
Unitary gates are an interesting resource for quantum communication in part
because they are always invertible and are intrinsically bidirectional. This
paper explores these two symmetries: time-reversal and exchange of Alice and
Bob. We will present examples of unitary gates that exhibit dramatic
separations between forward and backward capacities (even when the back
communication is assisted by free entanglement) and between
entanglement-assisted and unassisted capacities, among many others. Along the
way, we will give a general time-reversal rule for relating the capacities of a
unitary gate and its inverse that will explain why previous attempts at finding
asymmetric capacities failed. Finally, we will see how the ability to erase
quantum information and destroy entanglement can be a valuable resource for
quantum communication.Comment: 17 pages. v2: improved bounds, clarified proofs. v3: published
version, added section explaining notatio
Planar micromachined glass cantilevers utilising integrated Bragg Fabry-Perot cavities
Here we demonstrate a glass cantilever based on a unique micromachining and etching approach, combined with UV written Bragg gratings. We shall also discuss the increase in sensitivity by using two Bragg gratings to form Fabry-Pérot cavity. Cantilevers are in ultra sensitive force sensors used in applications such as Atomic Force Microscopy, mass sensing and acoustic transducers
Flat fiber: the flexible format for distributed lab-on-a-chip
Integrated optical devices offer dense, multifunctional capability in a single robust package but are rarely considered compatible with the fields of remote or distributed sensing or long-haul 'one-dimensional' fibers. Here we aim to change that by introducing a 'flat-fiber' process that combines the advantages of existing low-cost fiber drawing with the functionality of planar lightwave circuits in a novel hybrid format. By taking this approach, we hope to extend beyond the limitations of traditional planar and fiber substrates - allowing exotic material compositions, device layouts, and local sensing functions to be distributed over extended distances with no coupling or compatibility concerns in highly functional distributed lab-on-a-chip devices
Lateral groove geometry for planar UV written evanescent devices - new flexibility new devices
Conventional evanescent optical devices have made use of etched windows to allow access of an optical field to a material of interest. Such devices are a route to accurate refractive index sensors and to realising modulators, however, the geometry of etching the cladding to give the fluid access to a pre-defined core waveguide mode is limiting. In this work, we present an alternative approach in which a groove is cut using a polishing saw blade to give a vertical, high optical quality trench. Optical waveguides are then UV written to allow evanescent lateral access of the mode to a fluid placed in the trench. This seemingly subtle change in geometry provides greatly increased flexibility to tailor the interaction between the optical mode and the surrounding material, by, for example, changing the mode size and the allowing couplers or tapers to be used
Healthcare reform in Australia and New Zealand over recent decades Part B - Australia
Often policy and institutional reform proposals, developed through experience and learning transfers from other jurisdictions, encounter many veto points/players before they can be implemented. When New Zealand elected members by a first-past-the post voting system in single member electorates to a unicameral parliament it was relatively easy for the majority party to legislate their reform proposals. However, if reform legislation is not supported by the electorate it can be reversed just as easily by an incoming government of a different ideological persuasion. The situation is different in Australia because it is a federation and restricted by its constitution. It also has a bicameral parliamentary system that makes it easy for veto players, with ideologies opposed to that of the government, to reject policy reform proposals before they can be legislated into law. Despite these difficulties, some significant health care policy reforms have been enacted in both Australia and New Zealand during recent decades
New geometry for planar UV written refractive index sensors
We shall present some of our recent results from our work on UV written planar waveguide refractive index sensors. Refractive index of an analyte is measured through the perturbation of an optical mode, interrogation of the modal index is achieved via the reflected spectra from a Bragg grating defined in the same process as the channel waveguide. Here we introduce a new geometry which embraces the benefits of planar technology to realise new integrated devices. The geometry allows several different sensors to be defined on the same substrate each offering complementary information. Such information may include index as a function of penetration depth for surface binding analytes, interrogation wavelength for dispersion analysis, enhanced sensitivity in specific index ranges and temperature compensation. We shall also outline the inherent fabrication advantages and device feature benefits, including a reduction in return loss, spectral artefacts and a suggested reduction in stress induced birefringence. The silica sensing surface opposed to gold used in SPR devices opens new avenues to exploit surface binding. With a marked reduction in complexity and cost these devices may have significant impact in future sensor markets
Crossing the technology adoption chasm: implications for DoD
Acquisition research (Graduate School of Business & Public Policy)DoD faces significant challenges in delivering promising new technologies to service members quickly and cost-effectively. To better understand DOD's technology adoption challenges, we review the technology diffusion literature to identify factors associated with successful and unsuccessful technology adoption processes, conduct case studies of DoD's advanced technology programs and propose a conceptual technology adoption model. The literature review identifies three overarching factors reflecting the complexities of defense technology adoption: benefit-cost uncertainty, organizational externalities, and direct and indirect network externalities. Technology adoption clearly involves benefit and cost uncertainties. Organizational externalities arise because there are typically multiple stakeholders from different DoD constituencies. Direct and indirect network externalities reflect the joint and interrelated nature of defense technologies on the battlefield. A closer look at one of DoD's advanced technology development programs indicates that success factors in this program generally parallel the results of the literature survey: the importance of benefit-cost uncertainty, management commitment (organizational externalities), technology champion (network externalities) and the prospects for future technology transfer (network externalities). Finally, we present conceptual technology adoption models incorporating benefit-cost uncertainty, organizational externalities and network externalities. These models can explain the diffusion patterns observed in the defense department: no adoption, full adoption, and partial adoption/de-adoption.Approved for public release; distribution is unlimited
Survey of Australians using cannabis for medical purposes
BACKGROUND: The New South Wales State Government recently proposed a trial of the medical use of cannabis. Australians who currently use cannabis medicinally do so illegally and without assurances of quality control. Given the dearth of local information on this issue, this study explored the experiences of medical cannabis users. METHODS: Australian adults who had used cannabis for medical purposes were recruited using media stories. A total of 147 respondents were screened by phone and anonymous questionnaires were mailed, to be returned by postage paid envelope. RESULTS: Data were available for 128 participants. Long term and regular medical cannabis use was frequently reported for multiple medical conditions including chronic pain (57%), depression (56%), arthritis (35%), persistent nausea (27%) and weight loss (26%). Cannabis was perceived to provide "great relief" overall (86%), and substantial relief of specific symptoms such as pain, nausea and insomnia. It was also typically perceived as superior to other medications in terms of undesirable effects, and the extent of relief provided. However, nearly one half (41%) experienced conditions or symptoms that were not helped by its use. The most prevalent concerns related to its illegality. Participants reported strong support for their use from clinicians and family. There was almost universal interest (89%) in participating in a clinical trial of medical cannabis, and strong support (79%) for investigating alternative delivery methods. CONCLUSION: Australian medical cannabis users are risking legal ramifications, but consistent with users elsewhere, claim moderate to substantial benefits from its use in the management of their medical condition. In addition to strong public support, medical cannabis users show strong interest in clinical cannabis research, including the investigation of alternative delivery methods
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