2,440 research outputs found
Multiparametric Cardiac 18F-FDG PET in Humans: Kinetic Model Selection and Identifiability Analysis
Cardiac 18F-FDG PET has been used in clinics to assess myocardial glucose
metabolism. Its ability for imaging myocardial glucose transport, however, has
rarely been exploited in clinics. Using the dynamic FDG-PET scans of ten
patients with coronary artery disease, we investigate in this paper appropriate
dynamic scan and kinetic modeling protocols for efficient quantification of
myocardial glucose transport. Three kinetic models and the effect of scan
duration were evaluated by using statistical fit quality, assessing the impact
on kinetic quantification, and analyzing the practical identifiability. The
results show that the kinetic model selection depends on the scan duration. The
reversible two-tissue model was needed for a one-hour dynamic scan. The
irreversible two-tissue model was optimal for a scan duration of around 10
minutes. If the scan duration was shortened to 2 minutes, a one-tissue model
was the most appropriate. For global quantification of myocardial glucose
transport, we demonstrated that an early dynamic scan with a duration of 10
minutes and irreversible kinetic modeling was comparable to the full one-hour
scan with reversible kinetic modeling. Myocardial glucose transport
quantification provides an additional physiological parameter on top of the
existing assessment of glucose metabolism, which may be used as a surrogate of
myocardial blood flow to enable single tracer multiparametric imaging in the
myocardium.Comment: 10 pages, 8 figure
The prevalence of hepatitis C virus among people of South Asian origin in Glasgow: results from a community based survey and laboratory surveillance
Background South Asians often present late with HCV or HBV related liver disease which could have been avoided with early diagnosis and subsequent treatment; however the prevalence of HCV/HBV among South Asians in Glasgow is not known. Accordingly, to inform the need for case finding among this group we aimed to examine the prevalence of Hepatitis C virus (HCV) among South Asians living in Glasgow. Methods A community-based survey recruited individuals at six mosques and four community centres serving the South Asian community during 2009-2010; participants had predominantly never been HCV tested. Laboratory surveillance data involving all individuals tested for HCV during 1993-2009 were examined and South Asians were identified using Nam Pehchan software. Results In the community-based survey, 2.6% of 1288 participants tested HCV-antibody positive; the prevalence ranged from 0.6% among those born in the UK to 3.1% among those born in Pakistan. The odds of testing HCV-antibody positive were significantly raised among those who had surgery in South Asia (aOR: 5.0, 95% CI: 2.0-12.3) and had either medical/dental treatment or an injection in South Asia (aOR: 2.2, 95% CI: 1.0-5.0). Of 6404 South Asians identified from laboratory surveillance data, 9.3% tested HCV positive. An estimated 38% (330/870) of HCV-infected South Asians living in Glasgow remain undiagnosed. Conclusions South Asians living in Glasgow, particularly those born outside the UK are at greater risk of HCV infection than the general population. Efforts to increase awareness and testing in this population are warranted.</p
Access to and experience of later abortion: accounts from women in Scotland
Context:
Except in the presence of significant medical indications, the legal limit for abortion in Great Britain is 24 weeks’ gestation. Nevertheless, abortion for nonmedical reasons is not usually provided in Scotland after 18–20 weeks, meaning women have to travel to England for the procedure.
Methods:
In-depth interviews were conducted with 23 women presenting for "later" abortions (i.e., at 16 or more weeks’ gestation) in Scotland. Participants were women who sought an abortion at a participating National Health Service clinic between January and July 2013. Interviews addressed reasons for and consequences of later presentation, as well as women's experiences of abortion. Thematic analysis attended to emerging issues and employed the conceptual tool of candidacy.
Results:
Delayed recognition of pregnancy, changed life circumstances and conflicting candidacies for motherhood and having an abortion were common reasons for women's presentation for later abortion. Women perceived that the resources required to travel to England for a later abortion were potential barriers to access, and felt that such travel was distressing and stigmatizing. Participants who continued their pregnancy did so after learning they were at a later gestational age than expected or after receiving assurances of support from partners, friends or family.
Conclusions:
Reasons for seeking later abortion are complex and varied among women in Scotland, and suggest that reducing barriers to access and improving local provision of such abortions are a necessity. The candidacy framework allows for a fuller understanding of the difficulties involved in obtaining abortions
Public administration in an age of austerity:the future of the discipline
Reflecting changes in the nature of governance, some have questioned whether Public Administration is now an historical anachronism. While a legitimate debate exists between sceptics and optimists, this special issue demonstrates grounds for optimism by indicating the continuing diversity and adaptability of the field of Public Administration. In this introduction, we first sketch the variety of intellectual traditions which comprise the field of modern Public Administration. We then consider institutional challenges facing the subject given considerable pressures towards disciplinary fragmentation, and ideological challenges arising from a new distrust of public provision in the UK. Despite these challenges, Public Administration continues to provide a framework to analyse the practice of government and governance, governing institutions and traditions, and their wider sociological context. It can also directly inform policy reform - even if this endeavour can have its own pitfalls and pratfalls for the 'engaged' academic. We further suggest that, rather than lacking theoretical rigour, new approaches are developing that recognise the structural and political nature of the determinants of public administration. Finally, we highlight the richness of modern comparative work in Public Administration. Researchers can usefully look beyond the Atlantic relationship for theoretical enhancement and also consider more seriously the recursive and complex nature of international pressures on public administration
Study protocol: developing a decision system for inclusive housing: applying a systematic, mixed-method quasi-experimental design
Background Identifying the housing preferences of people with complex disabilities is a much needed, but under-developed area of practice and scholarship. Despite the recognition that housing is a social determinant of health and quality of life, there is an absence of empirical methodologies that can practically and systematically involve consumers in this complex service delivery and housing design market. A rigorous process for making effective and consistent development decisions is needed to ensure resources are used effectively and the needs of consumers with complex disability are properly met. Methods/Design This 3-year project aims to identify how the public and private housing market in Australia can better respond to the needs of people with complex disabilities whilst simultaneously achieving key corporate objectives. First, using the Customer Relationship Management framework, qualitative (Nominal Group Technique) and quantitative (Discrete Choice Experiment) methods will be used to quantify the housing preferences of consumers and their carers. A systematic mixed-method, quasi-experimental design will then be used to quantify the development priorities of other key stakeholders (e.g., architects, developers, Government housing services etc.) in relation to inclusive housing for people with complex disabilities. Stakeholders randomly assigned to Group 1 (experimental group) will participate in a series of focus groups employing Analytical Hierarchical Process (AHP) methodology. Stakeholders randomly assigned to Group 2 (control group) will participate in focus groups employing existing decision making processes to inclusive housing development (e.g., Risk, Opportunity, Cost, Benefit considerations). Using comparative stakeholder analysis, this research design will enable the AHP methodology (a proposed tool to guide inclusive housing development decisions) to be tested. Discussion It is anticipated that the findings of this study will enable stakeholders to incorporate consumer housing preferences into commercial decisions. Housing designers and developers will benefit from the creation of a parsimonious set of consumer-led housing preferences by which to make informed investments in future housing and contribute to future housing policy. The research design has not been applied in the Australian research context or elsewhere, and will provide a much needed blueprint for market investment to develop viable, consumer directed inclusive housing options for people with complex disability
Quality of life and sexual function after high-dose or conventional chemotherapy for high-risk breast cancer
Three hundred and ninety women participated in the quality of life (QL) study of ACCOG1, a high-dose vs conventional adjuvant chemotherapy breast cancer trial, for patients with a high risk of relapse. Patients completed the European Organisation for Research and Treatment of Cancer QLQ-C30, questions on menopausal symptoms and the Sexual Activity Questionnaire. Pretreatment, 6,12, 24, 36, 48 and 60-month assessments were conducted. For the high dose group the median decrease in global QL at 6 months was significantly greater than in the conventional group. At 12 months, however, the median change had returned to 0 for both groups. Social functioning was also significantly lower in the high-dose group at 6 months, again returning to prebaseline levels for both groups after 12 months. The most persistent changes appear to be in the effect of treatment in both arms on sexual outcomes, reflected in problems with discomfort and pleasure. Both high-dose and conventional chemotherapy showed persisting negative effects on sexual health. This has not been previously reported as a long-term complication of high-dose chemotherapy. However, it did not have long-term affects on sexual habit, which appeared to return to pretreatment frequency and similar to that of conventional chemotherapy by about 12 months from treatment
Implementation of a novel stratified PAthway of CarE for common musculoskeletal (MSK) conditions in primary care: Protocol for a multicentre pragmatic randomised controlled trial (the PACE MSK trial)
Introduction Musculoskeletal (MSK) conditions constitute the highest burden of disease globally, with healthcare services often utilised inappropriately and overburdened. The aim of this trial is to evaluate the effectiveness of a novel clinical PAthway of CarE programme (PACE programme), where care is provided based on people's risk of poor outcome. Methods and analysis Multicentre randomised controlled trial. 716 people with MSK conditions (low back pain, neck pain or knee osteoarthritis) will be recruited in primary care. They will be stratified for risk of a poor outcome (low risk/high risk) using the Short Form Örebro Musculoskeletal Pain Screening Questionnaire (SF-ÖMSPQ) then randomised to usual care (n=358) or the PACE programme (n=358). Participants at low risk in the PACE programme will receive up to 3 sessions of guideline based care from their primary healthcare professional (HCP) supported by a custom designed website (mypainhub.com). Those at high risk will be referred to an allied health MSK specialist who will conduct a comprehensive patient-centred assessment then liaise with the primary HCP to determine further care. Primary outcome (SF 12-item PCS) and secondary outcomes (eg, pain self-efficacy, psychological health) will be collected at baseline, 3, 6 and 12 months. Cost-effectiveness will be measured as cost per quality-Adjusted life-year gained. Health economic analysis will include direct and indirect costs. Analyses will be conducted on an intention-To-Treat basis. Primary and secondary outcomes will be analysed independently, using generalised linear models. Qualitative and mixed-methods studies embedded within the trial will evaluate patient experience, health professional practice and interprofessional collaboration. Ethics and dissemination Ethics approval has been received from the following Human Research Ethics Committees: The University of Sydney (2018/926), The University of Queensland (2019000700/2018/926), University of Melbourne (1954239), Curtin University (HRE2019-0263) and Northern Sydney Local Health District (2019/ETH03632). Dissemination of findings will occur via peer-reviewed publications, conference presentations and social media. Trial registration number ACTRN12619000871145
Carbon ion acceleration from thin foil targets irradiated by ultrahigh-contrast, ultraintense laser pulses
In this study, ion acceleration from thin planar target foils irradiated by ultrahigh-contrast (10(10)), ultrashort (50 fs) laser pulses focused to intensities of 7 x 10(20) W cm(-2) is investigated experimentally. Target normal sheath acceleration (TNSA) is found to be the dominant ion acceleration mechanism when the target thickness is >= 50 nm and laser pulses are linearly polarized. Under these conditions, irradiation at normal incidence is found to produce higher energy ions than oblique incidence at 35 degrees with respect to the target normal. Simulations using one-dimensional (1D) boosted and 2D particle-in-cell codes support the result, showing increased energy coupling efficiency to fast electrons for normal incidence. The effects of target composition and thickness on the acceleration of carbon ions are reported and compared to calculations using analytical models of ion acceleration
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