49 research outputs found

    The lack of variability of the iron line in MCG-6-30-15: general relativistic effects

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    The spectrum and variability of the Seyfert galaxy MCG-6-30-15 can be decomposed into two apparently disconnected components: a highly variable power law and an almost constant component which contains a broad and strong iron line. We explore a possible explanation of the puzzling lack of variability of the iron line, by assuming that the variations of the power law component are due to changes in the height of the primary source in the near vicinity of a rotating black hole. Due to the bending of light in the strong field of the central black hole, the apparent brightness of the power-law component can vary by about a factor 4 according to its position, while the total iron line flux variability is less than 20 percent. This behaviour is obtained if the primary source is located within 3-4 gravitational radii (rgr_{\rm g}) from the rotation axis with a variable height of between \sim 3 and 8 rgr_{\rm g}. These results revive the possibility that future X-ray observations of MCG-6-30-15 can map out the strong gravity regime of accreting black holes.Comment: accepted for publication in MNRAS Letter

    Can community-based peer support promote health literacy and reduce inequalities? A realist review.

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    Background Community-based peer support (CBPS) has been proposed as a potentially promising approach to improve health literacy (HL) and reduce health inequalities. Peer support, however, is described as a public health intervention in search of a theory, and as yet there are no systematic reviews exploring why or how peer support works to improve HL. Objective To undertake a participatory realist synthesis to develop a better understanding of the potential for CBPS to promote better HL and reduce health inequalities. Data sources Qualitative evidence syntheses, conceptual reviews and primary studies evaluating peer-support programmes; related studies that informed theoretical or contextual elements of the studies of interest were included. We conducted searches covering 1975 to October 2011 across Scopus, Global Health (including MEDLINE), ProQuest Dissertations & Theses database (PQDT) [including the Education Resources Information Center (ERIC) and Social Work Abstracts], The King’s Fund Database and Web of Knowledge, and the Institute of Development Studies supplementary strategies were used for the identification of grey literature. We developed a new approach to searching called ‘cluster searching’, which uses a variety of search techniques to identify papers or other research outputs that relate to a single study. Study eligibility criteria Studies written in English describing CBPS research/evaluation, and related papers describing theory, were included. Study appraisal and synthesis methods Studies were selected on the basis of relevance in the first instance. We first analysed within-programme articulation of theory and appraised for coherence. Cross-programme analysis was used to configure relationships among context, mechanisms and outcomes. Patterns were then identified and compared with theories relevant to HL and health inequalities to produce a middle-range theory. Results The synthesis indicated that organisations, researchers and health professionals that adopt an authoritarian design for peer-support programmes risk limiting the ability of peer supporters (PSs) to exercise autonomy and use their experiential knowledge to deliver culturally tailored support. Conversely, when organisations take a negotiated approach to codesigning programmes, PSs are enabled to establish meaningful relationships with people in socially vulnerable groups. CBPS is facilitated when organisations prioritise the importance of assessing community needs; investigate root causes of poor health and well-being; allow adequate time for development of relationships and connections; value experiential cultural knowledge; and share power and control during all stages of design and implementation. The theory now needs to be empirically tested via further primary research. Limitations Analysis and synthesis were challenged by a lack of explicit links between peer support for marginalised groups and health inequalities; explicitly stated programme theory; inconsistent reporting of context and mechanism; poor reporting of intermediate process outcomes; and the use of theories aimed at individual-level behaviour change for community-based interventions. Conclusions Peer-support programmes have the potential to improve HL and reduce health inequalities but potential is dependent upon the surrounding equity context. More explicit empirical research is needed, which establishes clearer links between peer-supported HL and health inequalities

    In Their Own Words: Assessment of Satisfaction with Residential Location among Migrants in Nairobi Slums

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    Using qualitative data collected from a sample of rural-urban migrants over the age of 15 in two Nairobi slums interviewed in 2008, this paper discusses the migrants’ extent of satisfaction with their residential location and decision to migrate. The study sheds light on why people continue to migrate to, and stay in, the rapidly growing slum settlements despite the high levels of poverty and poor health conditions in these areas. Tenure status is related to satisfaction for all ages. Environmental factors were frequently mentioned as a source of dissatisfaction. Life cycle and ‘age-cohort effects’ may also affect satisfaction for different age groups in terms of who is satisfied as well as the issues that are considered for satisfaction. High levels of dissatisfaction with slum life may be responsible for high out-migration in slum areas, although it does not mean that those who remain do so because they are satisfied. At the same time, challenges associated with slum life do not automatically signify dissatisfaction. Perceived success, as well as conditions in the area of origin can be used to explain and understand satisfaction/dissatisfaction with slum life. Satisfaction with migration and residential location may be related not only to the destination place, but also to events in the area of origin

    INVESTIGATE-I (INVasive Evaluation before Surgical Treatment of Incontinence Gives Added Therapeutic Effect?): study protocol for a mixed methods study to assess the feasibility of a future randomised controlled trial of the clinical utility of invasive urodynamic testing

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    <p>Abstract</p> <p>Background</p> <p>Urinary incontinence is an important health problem to the individual sufferer and to health services. Stress and stress predominant mixed urinary incontinence are increasingly managed by surgery due to advances in surgical techniques. Despite the lack of evidence for its clinical utility, most clinicians undertake invasive urodynamic testing (IUT) to confirm a functional diagnosis of urodynamic stress incontinence before offering surgery for this condition. IUT is expensive, embarrassing and uncomfortable for women and carries a small risk. Recent systematic reviews have confirmed the lack of high quality evidence of effectiveness.</p> <p>The aim of this pilot study is to test the feasibility of a future definitive randomised control trial that would address whether IUT alters treatment decisions and treatment outcome in these women and would test its clinical and cost effectiveness.</p> <p>Methods/design</p> <p>This is a mixed methods pragmatic multicentre feasibility pilot study with four components:-</p> <p>(a) A multicentre, external pilot randomised trial comparing basic clinical assessment with non-invasive tests and IUT. The outcome measures are rates of recruitment, randomisation and data completion. Data will be used to estimate sample size necessary for the definitive trial.</p> <p>(b) Qualitative interviews of a purposively sampled sub-set of women eligible for the pilot trial will explore willingness to participate, be randomised and their overall trial experience.</p> <p>(c) A national survey of clinicians to determine their views of IUT in this context, the main outcome being their willingness to randomise patients into the definitive trial.</p> <p>(d) Qualitative interviews of a purposively sampled group of these clinicians will explore whether and how they use IUT to inform their decisions.</p> <p>Discussion</p> <p>The pilot trial will provide evidence of feasibility and acceptability and therefore inform the decision whether to proceed to the definitive trial. Results will inform the design and conduct of the definitive trial and ensure its effectiveness in achieving its research aim.</p> <p>Trial registration number</p> <p>Current Controlled Trials <a href="http://www.controlled-trials.com/ISRCTN71327395">ISRCTN71327395</a> assigned 7<sup>th </sup>June 2010.</p

    Genomic insights into rapid speciation within the world's largest tree genus Syzygium

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    The relative importance of the mechanisms underlying species radiation remains unclear. Here, the authors combine reference genome assembly and population genetics analyses to show that neutral forces have contributed to the radiation of the most species-rich tree genus Syzygium. Species radiations, despite immense phenotypic variation, can be difficult to resolve phylogenetically when genetic change poorly matches the rapidity of diversification. Genomic potential furnished by palaeopolyploidy, and relative roles for adaptation, random drift and hybridisation in the apportionment of genetic variation, remain poorly understood factors. Here, we study these aspects in a model radiation, Syzygium, the most species-rich tree genus worldwide. Genomes of 182 distinct species and 58 unidentified taxa are compared against a chromosome-level reference genome of the sea apple, Syzygium grande. We show that while Syzygium shares an ancient genome doubling event with other Myrtales, little evidence exists for recent polyploidy events. Phylogenomics confirms that Syzygium originated in Australia-New Guinea and diversified in multiple migrations, eastward to the Pacific and westward to India and Africa, in bursts of speciation visible as poorly resolved branches on phylogenies. Furthermore, some sublineages demonstrate genomic clines that recapitulate cladogenetic events, suggesting that stepwise geographic speciation, a neutral process, has been important in Syzygium diversification.Peer reviewe

    Genomic insights into rapid speciation within the world's largest tree genus Syzygium

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    Acknowledgements Y.W.L. was supported by a postgraduate scholarship research grant from the Ministry of National Development, Singapore awarded through the National Parks Board, Singapore (NParks; NParks’ Garden City Fund). Principal research funding from NParks and the School of Biological Sciences (SBS), Nanyang Technological University (NTU), Singapore, is acknowledged. We thank Peter Preiser, Associate Vice President for Biomedical and Life Sciences, for facilitating NTU support, and Kenneth Er, CEO of NParks, for facilitating research funding through that organisation. V.A.A. and C.L. were funded by SBS, NTU for a one-year research leave. V.A.A. and C.L. also acknowledge support from the United States National Science Foundation (grants 2030871 and 1854550, respectively). S.R. was supported by a postdoctoral research fellowship under the NTU Strategic Plant Programme. S.R. and N.R.W.C. acknowledge funding from NTU start-up and the Academy of Finland (decisions 318288, 319947) grants to J.S. Fieldwork conducted by Y.W.L. was supported by an Indonesian Government RISTEK research permit (Application ID: 1517217008) and an Access License from the Sabah State government [JKM/MBS.1000-2/2JLD.7(84)]. T.N.C.V. is grateful to the Assemblée de la Province Nord and Assemblée de la Province Sud (New Caledonia) for facilitating relevant collection permits. A.N. was partly supported by the Research Project Promotion Grant (Strategic Research Grant No. 17SP01302) from the University of the Ryukyus, and partly by the Environment Research and Technology Development Fund (JPMEERF20204003) from the Environmental Restoration and Conservation Agency of Japan. Fieldwork in Fiji conducted by R.B. was hosted and facilitated by Elina Nabubuniyaka-Young (The Pacific Community’s Centre for Pacific Crops and Trees, Fiji). We thank the NTU-Smithsonian Partnership for tree data obtained for the Bukit Timah Nature Reserve (BTNR) long-term forest dynamics plots. Administrative support provided by Mui Hwang Khoo-Woon and Peter Ang at the molecular laboratory of the Singapore Botanic Gardens (SBG) is acknowledged. Rosie Woods and Imalka Kahandawala (DNA and Tissue Bank, Royal Botanic Gardens, Kew) facilitated additional DNA samples. Daniel Thomas (SBG) and Yan Yu (Sichuan University) commented on biogeographical analyses. NovogeneAIT in Singapore is acknowledged for personalised sequencing service.Peer reviewedPublisher PD

    Prediksi Kenaikan atau Penurunan Indeks Pasar Keuangan Indonesia dengan Menggunakan Bayesian Network

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    Investasi saham pada pasar keuangan dilakukan untuk meningkatkan aset pada masa depan. Dalam melakukan investasi harus mempertimbangkan hasil yang akan didapatkan atau biasa disebut return. Setiap investor akan berusaha mendapatkan return semaksimal mungkin dari investasi yang dilakukannya. Oleh karena itu, perlu dilakukan prediksi perubahan kenaikan atau penurunan pada pasar saham. Beberapa metode untuk membuat prediksi adalah Bayesian Network dan Algoritma Naive Bayes. Pada Tugas Akhir ini, dilakukan pemodelan jaringan sektor-sektor pasar keuangan Indonesia dengan menggunakan Bayesian Network, lalu melakukan prediksi berdasarkan kenaikan atau penurunan harga penutupan dari tiap sektor. Metode yang digunakan adalah menggunakan Algoritma Naive Bayes Diskrit dan Kontinu. Setelah itu, menentukan metode yang terbaik untuk perhitungan prediksi dengan melihat tingkat akurasi dari setiap metode dengan confusion matrix. Sektor pasar keuangan yang digunakan yaitu nilai tukar USD/IDR, IHSG, dan Obligasi. Perhitungan dilakukan berdasarkan ketergantungan antara nilai tukar USD/IDR terhadap IHSG, dan nilai tukar USD/IDR terhadap Obligasi. Metode Naive Bayes Diskrit menunjukan hasil yang lebih akurat dengan akurasi sebesar 84% untuk IHSG dan 76% untuk Obligasi. Sedangkan perhitungan dengan metode Naive Bayes Kontinu memiliki akurasi sebesar 52% untuk IHSG dan 48% untuk Obligasi. Sektor nilai tukar USD/IDR lebih mempengaruhi IHSG, karena tingkat akurasi yang diperoleh IHSG lebih tinggi dibandingkan dengan Obligasi

    Is a large scale community programme as effective as a community rehabilitation programme delivered in the setting of a clinical trial?

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    Background The rationale for commissioning community pulmonary rehabilitation programmes is based on evidence from randomised clinical trials. However, there are a number of reasons why similar programmes might be less effective outside the environment of a clinical trial. These include a less highly selected patient group and less control over the fidelity of intervention delivery. The main objective of this study was therefore to test the hypothesis that the real-world programme would have similar outcomes to an intervention delivered in the context of a clinical trial. Methods As part of the evaluation of an innovative community-based pulmonary rehabilitation programme (“BreathingSpace”), clinical and quality of life measures were collected before and after delivery of a rehabilitation programme. Baseline characteristics of participants and the change in symptoms and quality of life after the BreathingSpace programme were compared to measures collected in the community-based arm of a separate randomised trial of pulmonary rehabilitation. Results Despite differences between the BreathingSpace participants and research participants in clinical status at baseline, patient reported symptoms and quality of life measures were similar. Improvements in both symptoms and quality of life were of the same order of magnitude despite the different contexts, setting and scale of the two intervention programmes. Whilst 73% (326/448) of those considered suitable for community rehabilitation in the trial and 80% (393/491) assessed as suitable for the BreathingSpace programme agreed to participate, less than half of participants completed rehabilitation, whether in a research or “real world” setting ( 47% and 45% respectively). Conclusion The before-after changes in outcomes seen in a “real world” community rehabilitation programme are similar in magnitude to those seen in the intervention arm of a clinical trial. However suboptimal uptake and high dropout rates from rehabilitation amongst eligible participants occurs in both clinical trials and community based programmes and must be addressed if the benefits of rehabilitation for people with chronic lung disease are to be maximised

    In-vitro diagnostic point-of-care tests in paediatric ambulatory care: A systematic review and meta-analysis

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    INTRODUCTION: Paediatric consultations form a significant proportion of all consultations in ambulatory care. Point-of-care tests (POCTs) may offer a potential solution to improve clinical outcomes for children by reducing diagnostic uncertainty in acute illness, and streamlining management of chronic diseases. However, their clinical impact in paediatric ambulatory care is unknown. We aimed to describe the clinical impact of all in-vitro diagnostic POCTs on patient outcomes and healthcare processes in paediatric ambulatory care. METHODS: We searched MEDLINE, EMBASE, Pubmed, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Web of Science from inception to 29 January 2020 without language restrictions. We included studies of children presenting to ambulatory care settings (general practice, hospital outpatient clinics, or emergency departments, walk-in centres, registered drug shops delivering healthcare) where in-vitro diagnostic POCTs were compared to usual care. We included all quantitative clinical outcome data across all conditions or infection syndromes reporting on the impact of POCTs on clinical care and healthcare processes. Where feasible, we calculated risk ratios (RR) with 95% confidence intervals (CI) by performing meta-analysis using random effects models. RESULTS: We included 35 studies. Data relating to at least one outcome were available for 89,439 children of whom 45,283 had a POCT across six conditions or infection syndromes: malaria (n = 14); non-specific acute fever 'illness' (n = 7); sore throat (n = 5); acute respiratory tract infections (n = 5); HIV (n = 3); and diabetes (n = 1). Outcomes centred around decision-making such as prescription of medications or hospital referral. Pooled estimates showed that malarial-POCTs (Plasmodium falciparum) better targeted antimalarial treatment by reducing over-treatment by a third compared to usual care (RR 0.67; 95% CI [0.58 to 0.77], n = 36,949). HIV-POCTs improved initiating earlier antiretroviral therapy compared to usual care (RR, 3.11; 95% CI [1.55 to 6.25], n = 912). Across the other four conditions, there was limited evidence for the benefit of POCTs in paediatric ambulatory care except for acute respiratory tract infections (RTI) in low-and-middle-income countries (LMICs), where POCT C-Reactive Protein (CRP) may reduce immediate antibiotic prescribing by a third (risk difference, -0.29 [-0.47, -0.11], n = 2,747). This difference was shown in randomised controlled trials in LMICs which included guidance on interpretation of POCT-CRP, specific training or employed a diagnostic algorithm prior to POC testing. CONCLUSION: Overall, there is a paucity of evidence for the use of POCTs in paediatric ambulatory care. POCTs help to target prescribing for children with malaria and HIV. There is emerging evidence that POCT-CRP may better target antibiotic prescribing for children with acute RTIs in LMIC, but not in high-income countries. Research is urgently needed to understand where POCTs are likely to improve clinical outcomes in paediatric settings worldwide.status: publishe
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