281 research outputs found

    Ballistic missile defence: how soon, how significant, and what should Australia's policy be?

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    Summary: The issue of ballistic missile defence (BMD) was a controversial one when US President Reagan first advocated a strategic-level system in the early 1980s. It remains so today. What’s Australia’s interest? We live a long way away from most current ballistic missile arsenals. But the ADF frequently deploys within range of ballistic missile systems, especially in Northeast Asia or the Middle East, and those systems might proliferate more widely in the future. The paper considers the two questions we need to decide. The first is the priority for enhancing the ADF’s own BMD capabilities. The second is whether it makes sense for us to participate in a cooperative arrangement with the US or other partners

    Aircrew team management program

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    The key features of the Aircrew Team Management Workshop which was designed for and in consultation with Trans Australia Airlines are outlined. Five major sections are presented dealing with: (1) A profile of the airline and the designers; (2) Aircrew consultation and involvement; (3) Educational design and development; (4) Implementation and instruction; and (5) Evaluation and assessment. These areas are detailed

    The thin layer of Warm Ionized Gas: towards a 3-D reconstruction of the spatial distribution of HII regions

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    HII regions are known to contribute to the so-called thin layer of the diffuse Warm Ionized Gas. In order to constrain this contribution, we reconstruct the 3-D distribution of the sources. A detailed spatial analysis of the largest up-to-date sample of HII regions is presented.Comment: 4 pages, 3 figures, Proceedings of the September 2002 JENAM meeting: "From Observations to Self-Consistent Modeling of the Interstellar Medium", Porto, Portuga

    Compressing computer programs

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    This paper describes a scheme for compressing programs written in a particular programming language—which can be any language that has a formal lexical and syntactic description—in such a way that they can be reproduced exactly. Only syntactically correct programs can be compressed. The scheme is illustrated on the Pascal language, and compression results are given for a corpus of Pascal programs; but it is by no means restricted to Pascal. In fact, we discuss how a "compressor-generator" program can be constructed that creates a compressor automatically from a formal specification of a programming language, in much the same way as a parser generator creates a syntactic parser from a formal language description

    Determining the optimal time interval between sample acquisition and cryopreservation when processing immature testicular tissue to preserve fertility

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    The cryopreservation of immature testicular tissue (ITT) prior to gonadotoxic therapy is crucial for fertility preservation in prepubertal boys with cancer. However, the optimal holding time between tissue collection and cryopreservation has yet to be elucidated. Using the bovine model, we investigated four holding times (1, 6, 24, and 48 h) for ITTs before cryopreservation. Biopsies from two-week-old calves were stored in transport medium and cryopreserved following a standard slow-freezing clinical protocol. Thawed samples were then assessed for viability, morphology, and gene expression by haematoxylin and eosin (H&E) staining, immunohistochemistry and real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR). Analysis failed to identify any significant changes in cell viability when compared between the different groups. Sertoli (Vimentin+) and proliferating cells (Ki67+) were well-preserved. The expression of genes related to germ cells, spermatogenesis (STRA8, PLZF, GFRα-1, C-KIT, THY1, UCHL-1, NANOG, OCT-4, CREM), and apoptosis (HSP70-2) remained stable over 48 h. However, seminiferous cord detachment increased significantly in the 48-h group (p < 0.05), with associated cord and SSC shrinkage. Collectively, our analyses indicate that bovine ITTs can be stored for up to 48 h prior to cryopreservation with no impact on cell viability and the expression levels of key genes. However, to preserve the morphology of frozen-thawed tissue, the ideal processing time would be within 24 h. Testicular tissues obtained from patients for fertility preservation often need to be transported over long distances to be cryopreserved in specialist centres. Our findings highlight the importance of determining optimal tissue transport times to ensure tissue quality in cryopreservation

    The Effectiveness and Cost-Effectiveness of Spinal Cord Stimulation for Refractory Angina (RASCAL Study): A Pilot Randomized Controlled Trial

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    Background: Patients with “refractory angina” (RA) unsuitable for coronary revascularization experience high levels of hospitalization and poor health‐related quality of life. Randomized trials have shown spinal cord stimulation (SCS) to be a promising treatment for chronic stable angina and RA; however, none has compared SCS with usual care (UC). The aim of this pilot study was to address the key uncertainties of conducting a definitive multicenter trial to assess the clinical and cost‐effectiveness of SCS in RA patients, i.e., recruitment and retention of patients, burden of outcome measures, our ability to standardize UC in a UK NHS setting. Methods: RA patients deemed suitable were randomized in a 1:1 ratio to SCS plus UC (SCS group) or UC alone (UC group). We sought to assess: recruitment, uptake, and retention of patients; feasibility and acceptability of SCS treatment; the feasibility and acceptability of standardizing UC; and the feasibility and acceptability of the proposed trial outcome measures. Patient outcomes were assessed at baseline (prerandomization) and three and six months postrandomization. Results: We failed to meet our planned recruitment target (45 patients) and randomized 29 patients (15 SCS group, 14 UC group) over a 42‐month period across four sites. None of the study participants chose to withdraw following consent and randomization. With exception of two deaths, all completed evaluation at baseline and follow‐up. Although the study was not formally powered to compare outcomes between groups, we saw a trend toward larger improvements in both primary and secondary outcomes in the SCS group. Conclusions: While patient recruitment was found to be challenging, levels of participant retention, outcome completion, and acceptability of SCS therapy were high. A number of lessons are presented in order to take forward a future definitive pragmatic randomized trial

    Interventions to promote patient utilisation of cardiac rehabilitation

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    Background: International clinical practice guidelines routinely recommend that cardiac patients participate in rehabilitation programmes for comprehensive secondary prevention. However, data show that only a small proportion of these patients utilise rehabilitation. Objectives: First, to assess interventions provided to increase patient enrolment in, adherence to, and completion of cardiac rehabilitation. Second, to assess intervention costs and associated harms, as well as interventions intended to promote equitable CR utilisation in vulnerable patient subpopulations. Search methods: Review authors performed a search on 10 July 2018, to identify studies published since publication of the previous systematic review. We searched the Cochrane Central Register of Controlled Trials (CENTRAL); the National Health Service (NHS) Centre for Reviews and Dissemination (CRD) databases (Health Technology Assessment (HTA) and Database of Abstracts of Reviews of Effects (DARE)), in the Cochrane Library (Wiley); MEDLINE (Ovid); Embase (Elsevier); the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (EBSCOhost); and Conference Proceedings Citation Index ‐ Science (CPCI‐S) on Web of Science (Clarivate Analytics). We checked the reference lists of relevant systematic reviews for additional studies and also searched two clinical trial registers. We applied no language restrictions. Selection criteria: We included randomised controlled trials (RCTs) in adults with myocardial infarction, with angina, undergoing coronary artery bypass graft surgery or percutaneous coronary intervention, or with heart failure who were eligible for cardiac rehabilitation. Interventions had to aim to increase utilisation of comprehensive phase II cardiac rehabilitation. We included only studies that measured one or more of our primary outcomes. Secondary outcomes were harms and costs, and we focused on equity. Data collection and analysis: Two review authors independently screened the titles and abstracts of all identified references for eligibility, and we obtained full papers of potentially relevant trials. Two review authors independently considered these trials for inclusion, assessed included studies for risk of bias, and extracted trial data independently. We resolved disagreements through consultation with a third review author. We performed random‐effects meta‐regression for each outcome and explored prespecified study characteristics. Main results: Overall, we included 26 studies with 5299 participants (29 comparisons). Participants were primarily male (64.2%). Ten (38.5%) studies included patients with heart failure. We assessed most studies as having low or unclear risk of bias. Sixteen studies (3164 participants) reported interventions to improve enrolment in cardiac rehabilitation, 11 studies (2319 participants) reported interventions to improve adherence to cardiac rehabilitation, and seven studies (1567 participants) reported interventions to increase programme completion. Researchers tested a variety of interventions to increase utilisation of cardiac rehabilitation. In many studies, this consisted of contacts made by a healthcare provider during or shortly after an acute care hospitalisation. Low‐quality evidence shows an effect of interventions on increasing programme enrolment (19 comparisons; risk ratio (RR) 1.27, 95% confidence interval (CI) 1.13 to 1.42). Meta‐regression revealed that the intervention deliverer (nurse or allied healthcare provider; P = 0.02) and the delivery format (face‐to‐face; P = 0.01) were influential in increasing enrolment. Low‐quality evidence shows interventions to increase adherence were effective (nine comparisons; standardised mean difference (SMD) 0.38, 95% CI 0.20 to 0.55), particularly when they were delivered remotely, such as in home‐based programs (SMD 0.56, 95% CI 0.37 to 0.76). Moderate‐quality evidence shows interventions to increase programme completion were also effective (eight comparisons; RR 1.13, 95% CI 1.02 to 1.25), but those applied in multi‐centre studies were less effective than those given in single‐centre studies, leading to questions regarding generalisability. A moderate level of statistical heterogeneity across intervention studies reflects heterogeneity in intervention approaches. There was no evidence of small‐study bias for enrolment (insufficient studies to test for this in the other outcomes). With regard to secondary outcomes, no studies reported on harms associated with the interventions. Only two studies reported costs. In terms of equity, trialists tested interventions designed to improve utilisation among women and older patients. Evidence is insufficient for quantitative assessment of whether women‐tailored programmes were associated with increased utilisation, and studies that assess motivating women are needed. For older participants, again while quantitative assessment could not be undertaken, peer navigation may improve enrolment. Authors' conclusions: Interventions may increase cardiac rehabilitation enrolment, adherence and completion; however the quality of evidence was low to moderate due to heterogeneity of the interventions used, among other factors. Effects on enrolment were larger in studies targeting healthcare providers, training nurses, or allied healthcare providers to intervene face‐to‐face; effects on adherence were larger in studies that tested remote interventions. More research is needed, particularly to discover the best ways to increase programme completion

    Scoping and targeted reviews to support development of SPIRIT and CONSORT extensions for randomised controlled trials with surrogate primary endpoints: protocol

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    Introduction Using a surrogate endpoint as a substitute for a primary patient-relevant outcome enables randomised controlled trials (RCTs) to be conducted more efficiently, that is, with shorter time, smaller sample size and lower cost. However, there is currently no consensus-driven guideline for the reporting of RCTs using a surrogate endpoint as a primary outcome; therefore, we seek to develop SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) and CONSORT (Consolidated Standards of Reporting Trials) extensions to improve the design and reporting of these trials. As an initial step, scoping and targeted reviews will identify potential items for inclusion in the extensions and participants to contribute to a Delphi consensus process. Methods and analysis The scoping review will search and include literature reporting on the current understanding, limitations and guidance on using surrogate endpoints in trials. Relevant literature will be identified through: (1) bibliographic databases; (2) grey literature; (3) handsearching of reference lists and (4) solicitation from experts. Data from eligible records will be thematically analysed into potential items for inclusion in extensions. The targeted review will search for RCT reports and protocols published from 2017 to 2021 in six high impact general medical journals. Trial corresponding author contacts will be listed as potential participants for the Delphi exercise. Ethics and dissemination Ethical approval is not required. The reviews will support the development of SPIRIT and CONSORT extensions for reporting surrogate primary endpoints (surrogate endpoint as the primary outcome). The findings will be published in open-access publications. This review has been prospectively registered in the OSF Registration DOI: 10.17605/OSF.IO/WP3QH

    Galaxy redshift surveys selected by neutral hydrogen using FAST

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    We discuss the possibility of performing a substantial spectroscopic galaxy redshift survey selected via the 21cm emission from neutral hydrogen using the Five-hundred metre Aperture Spherical Telescope (FAST) to be built in China. We consider issues related to the estimation of the source counts and optimizations of the survey, and discuss the constraints on cosmological models that such a survey could provide. We find that a survey taking around two years could detect ~10^7 galaxies with an average redshift of ~0.15 making the survey complementary to those already carried out at optical wavelengths. These conservative estimates have used the z=0 HI mass function and have ignored the possibility of evolution. The results could be used to constrain Gamma = (Omega_m h) to 5 per cent and the spectral index, n_s, to 7 per cent independent of cosmic microwave background data. If we also use simulated power spectra from the Planck satellite, we can constrain w to be within 5 per cent of -1.Comment: 13 pages, 15 figures, Accepted by MNRAS, minor correction

    The C-Band All-Sky Survey: Instrument design, status, and first-look data

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    The C-Band All-Sky Survey (C-BASS) aims to produce sensitive, all-sky maps of diffuse Galactic emission at 5 GHz in total intensity and linear polarization. These maps will be used (with other surveys) to separate the several astrophysical components contributing to microwave emission, and in particular will allow an accurate map of synchrotron emission to be produced for the subtraction of foregrounds from measurements of the polarized Cosmic Microwave Background. We describe the design of the analog instrument, the optics of our 6.1 m dish at the Owens Valley Radio Observatory, the status of observations, and first-look data.Comment: 10 pages, 11 figures, published in Proceedings of SPIE MIllimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy V (2010), Vol. 7741, 77411I-1 - 77411I-1
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