72 research outputs found
NuStar observations of WISE J1036+0449, a galaxy at z ∼ 1 obscured by hot dust
Hot dust-obscured galaxies (hot DOGs), selected from Wide-Field Infrared Survey Explorer’s all-sky infrared survey, host some of the most powerful active galactic nuclei known and may represent an important stage in the evolution of galaxies. Most known hot DOGs are located at z> 1.5, due in part to a strong bias against identifying them at lower redshift related to the selection criteria. We present a new selection method that identifies 153 hot DOG candidates at z˜ 1, where they are significantly brighter and easier to study. We validate this approach by measuring a redshift z = 1.009 and finding a spectral energy distribution similar to that of higher-redshift hot DOGs for one of these objects, WISE J1036+0449 ({L}{Bol}≃ 8× {10}46 {erg} {{{s}}}-1). We find evidence of a broadened component in Mg II, which would imply a black hole mass of {M}{BH}≃ 2× {10}8 {M}⊙ and an Eddington ratio of {λ }{Edd}≃ 2.7. WISE J1036+0449 is the first hot DOG detected by the Nuclear Spectroscopic Telescope Array, and observations show that the source is heavily obscured, with a column density of {N}{{H}}≃ (2{--}15)× {10}23 {{cm}}-2. The source has an intrinsic 2-10 keV luminosity of ˜ 6× {10}44 {erg} {{{s}}}-1, a value significantly lower than that expected from the mid-infrared/X-ray correlation. We also find that other hot DOGs observed by X-ray facilities show a similar deficiency of X-ray flux. We discuss the origin of the X-ray weakness and the absorption properties of hot DOGs. Hot DOGs at z≲ 1 could be excellent laboratories to probe the characteristics of the accretion flow and of the X-ray emitting plasma at extreme values of the Eddington ratio
Sustainable Financing of Innovative Therapies: A Review of Approaches
The process of innovation is inherently complex, and it occurs within an even more complex institutional environment characterized by incomplete information, market power, and externalities. There are therefore different competing approaches to supporting and financing innovation in medical technologies, which bring their own advantages and disadvantages. This article reviews value- and cost-based pricing, as well direct government funding, and cross-cutting institutional structures. It argues that performance-based risk-sharing agreements are likely to have little effect on the sustainability of financing; that there is a role for cost-based pricing models in some situations; and that the push towards longer exclusivity periods is likely contrary to the interests of industry
A systematic review of economic analyses of telehealth services using real time video communication
Background: Telehealth is the delivery of health care at a distance, using information and communication technology. The major rationales for its introduction have been to decrease costs, improve efficiency and increase access in health care delivery. This systematic review assesses the economic value of one type of telehealth delivery - synchronous or real time video communication - rather than examining a heterogeneous range of delivery modes as has been the case with previous reviews in this area. Methods A systematic search was undertaken for economic analyses of the clinical use of telehealth, ending in June 2009. Studies with patient outcome data and a non-telehealth comparator were included. Cost analyses, non-comparative studies and those where patient satisfaction was the only health outcome were excluded. Results 36 articles met the inclusion criteria. 22(61%) of the studies found telehealth to be less costly than the non-telehealth alternative, 11(31%) found greater costs and 3 (9%) gave the same or mixed results. 23 of the studies took the perspective of the health services, 12 were societal, and one was from the patient perspective. In three studies of telehealth to rural areas, the health services paid more for telehealth, but due to savings in patient travel, the societal perspective demonstrated cost savings. In regard to health outcomes, 12 (33%) of studies found improved health outcomes, 21 (58%) found outcomes were not significantly different, 2(6%) found that telehealth was less effective, and 1 (3%) found outcomes differed according to patient group. The organisational model of care was more important in determining the value of the service than the clinical discipline, the type of technology, or the date of the study. Conclusion Delivery of health services by real time video communication was cost-effective for home care and access to on-call hospital specialists, showed mixed results for rural service delivery, and was not cost-effective for local delivery of services between hospitals and primary care
The geometry of the infrared and x-ray obscurer in a dusty hyperluminous quasar
We study the geometry of the active galactic nucleus (AGN) obscurer in IRAS 09104+4109, an IR-luminous, radio-intermediate FR-I source at = 0.442, using infrared data from and , X-ray data from , , , and , and an optical spectrum from Palomar. The infrared data imply a total rest-frame 1–1000 μm luminosity of 5.5 × 10 erg s and require both an AGN torus and a starburst model. The AGN torus has an anisotropy-corrected IR luminosity of 4.9 × 10 erg s and a viewing angle and half-opening angle both of approximately 36° from pole-on. The starburst has a star formation rate of (110 ± 34) yr and an age of <50 Myr. These results are consistent with two epochs of luminous activity in IRAS 09104+4109: one approximately 150 Myr ago, and one ongoing. The X-ray data suggest a photon index of Γ 1.8 and a line-of-sight column density of 5 × 10 cm. This argues against a reflection-dominated hard X-ray spectrum, which would have implied a much higher and luminosity. The X-ray and infrared data are consistent with a bolometric AGN luminosity of ~ (0.5–2.5) × 10 erg s. The X-ray and infrared data are further consistent with coaligned AGN obscurers in which the line of sight “skims” the torus. This is also consistent with the optical spectra, which show both coronal iron lines and broad lines in polarized but not direct light. Combining constraints from the X-ray, optical, and infrared data suggest that the AGN obscurer is within a vertical height of 20 pc, and a radius of 125 pc, of the nucleus.ERC (Advanced Grant Feedback 340442
From recommendation to action: psychosocial factors influencing physician intention to use Health Technology Assessment (HTA) recommendations
BACKGROUND: Evaluating the impact of recommendations based upon health technology assessment (HTA) represents a challenge for both HTA agencies and healthcare policy-makers. Using a psychosocial theoretical framework, this study aimed at exploring the factors affecting physician intention to adopt HTA recommendations. The selected recommendations were prioritisation systems for patients on waiting lists for two surgical procedures: hip and knee replacement and cataract surgery. METHODS: Determinants of physician intention to use HTA recommendations for patient prioritisation were assessed by a questionnaire based upon the Theory of Interpersonal Behaviour. A total of 96 physicians from two medical specialties (ophthalmology and orthopaedic surgery) responded to the questionnaire (response rate 44.2%). A multiple analysis of variance (MANOVA) was performed to assess differences between medical specialties on the set of theoretical variables. Given the main effect difference between specialties, two regression models were tested separately to assess the psychosocial determinants of physician intention to use HTA recommendations for the prioritisation of patients on waiting lists for surgical procedures. RESULTS: Factors influencing physician intention to use HTA recommendations differ between groups of specialists. Intention to use the prioritisation system for patients on waiting lists for cataract surgery among ophthalmologists was related to attitude towards the behaviour, social norms, as well as personal normative beliefs. Intention to use HTA recommendations for patient prioritisation for hip and knee replacement among orthopaedic surgeons was explained by: perception of conditions that facilitated the realisation of the behaviour, personal normative beliefs, and habit of using HTA recommendations in clinical work. CONCLUSION: This study offers a model to assess factors influencing the intention to adopt recommendations from health technology assessment into professional practice. Results identify determinant factors that should be considered in the elaboration of strategies to support the implementation of evidence-based practice, with respect to emerging health technologies and modalities of practice. However, it is important to emphasise that behavioural determinants of evidence-based practice vary according to the specific technology considered. Evidence-based implementation of HTA recommendations, as well as other evidence-based practices, should build on a theoretical understanding of the complex forces that shape the practice of healthcare professionals
The role of economic evaluation in the decision-making process of family physicians: design and methods of a qualitative embedded multiple-case study
<p>Abstract</p> <p>Background</p> <p>A considerable amount of resource allocation decisions take place daily at the point of the clinical encounter; especially in primary care, where 80 percent of health problems are managed. Ignoring economic evaluation evidence in individual clinical decision-making may have a broad impact on the efficiency of health services. To date, almost all studies on the use of economic evaluation in decision-making used a quantitative approach, and few investigated decision-making at the clinical level. An important question is whether economic evaluations affect clinical practice. The project is an intervention research study designed to understand the role of economic evaluation in the decision-making process of family physicians (FPs). The contributions of the project will be from the perspective of Pierre Bourdieu's sociological theory.</p> <p>Methods/design</p> <p>A qualitative research strategy is proposed. We will conduct an embedded multiple-case study design. Ten case studies will be performed. The FPs will be the unit of analysis. The sampling strategies will be directed towards theoretical generalization. The 10 selected cases will be intended to reflect a diversity of FPs. There will be two embedded units of analysis: FPs (micro-level of analysis) and field of family medicine (macro-level of analysis). The division of the determinants of practice/behaviour into two groups, corresponding to the macro-structural level and the micro-individual level, is the basis for Bourdieu's mode of analysis. The sources of data collection for the micro-level analysis will be 10 life history interviews with FPs, documents and observational evidence. The sources of data collection for the macro-level analysis will be documents and 9 open-ended, focused interviews with key informants from medical associations and academic institutions. The analytic induction approach to data analysis will be used. A list of codes will be generated based on both the original framework and new themes introduced by the participants. We will conduct within-case and cross-case analyses of the data.</p> <p>Discussion</p> <p>The question of the role of economic evaluation in FPs' decision-making is of great interest to scientists, health care practitioners, managers and policy-makers, as well as to consultants, industry, and society. It is believed that the proposed research approach will make an original contribution to the development of knowledge, both empirical and theoretical.</p
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