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Despite significant recent advancements in the sensor technologies, the use of sensors for raw material characterization in the mining industry remains limited. The aim of the present study was to assess the utility of applying the mid-wave infrared (MWIR) reflectance data acquired by the use of a handheld Fourier-transform infrared spectrometer (FTIR), combined with partial least squares-discriminant analysis (PLS-DA), for the characterization of a polymetallic sulphide ore deposit. In achieving the study objectives, focus was given to the MWIR portion of the FTIR dataset, as it is the least explored region of the infrared spectrum in mineral characterization studies. Three datasets—covering different wavelength ranges—were generated from the FTIR spectral data, namely the full FTIR range (2.5–15 µm), MWIR (2.5–7 µm) and long-wave infrared (LWIR: 7–15 µm), in order to investigate the associated information level of each defined wavelength region separately. Design of experiment was developed to determine the optimal data filtering techniques. Using the processed data and PLS-DA, a series of calibration and prediction models were developed for ore and waste materials separately. As the models applied to the MWIR data showed a successful classification rate of 86.3% for sulphide ore–waste discrimination, similarly using the full spectral FTIR dataset, a correct classification rate of 89.5% was achieved. This indicates that MWIR spectral range includes informative signals that are sufficient for classifying the material into ore or waste. The proposed approach could be extended for automating the sulphide ore–waste discrimination process, thus greatly benefiting marginally economical mining operations. [ABSTRACT FROM AUTHOR]

Near-infrared (NIR) and short-wavelength infrared (SWIR) hyperspectral imagery can be used to detect certain alteration minerals. At epithermal deposits, the formation of alteration minerals is, in theory, related to the mineralisation of gold and silver. In order to provide foundations for developing sensor-based sorting applications at a mine that exploits such a deposit, it was investigated if NIR-SWIR hyperspectral imagery can be used to distinguish between ore and waste particles by characterising the alteration mineralogy. Maps were produced from the NIR-SWIR hyperspectral images of 827 drill core samples that show mineral occurrences, mineral absorption feature intensities and characteristics of the iron oxide mineralogy. Partial least squares discriminant analysis (PLS-DA) was applied to the information contained in these maps to investigate if this information can be used to discriminate between ore and waste. The results showed that NIR-SWIR hyperspectral imagery could be used to segment a population of waste samples by detecting occurrences of pyrophyllite, dickite and/or illite. This result can be explained by the fact that these minerals are commonly deposited further away from the ore-bearing epithermal veins, while the absence of SWIR-active minerals or detected occurrences of alunite are more closely associated with these structures. The ability to identify waste with NIR-SWIR spectral sensors means there is potential that sensor-based sorting can be used to remove this waste from mineral processing operations. Additional research is still required to assess the economic feasibility of such a sensor-based sorting application. [ABSTRACT FROM AUTHOR]

In the production of calcined kaolin, the on-line monitoring of the calcination reaction is becoming more relevant for the generation of optimal products. In this context, this study aimed to assess the suitability of using infrared (IR) spectroscopy as a potential technique for the on-line characterization of the calcination of kaolin. The transformation of kaolin samples calcined at different temperatures were characterized in the short-wave (SWIR) spectra using the kaolinite crystallinity (Kx) index and the depth of the water spectral feature (1900D). A high correlation between the standard operational procedure for the quality control of calcined kaolin and the Kx index was observed (r = -0.89), as well as with the 1900D parameter (r = -0.96). This study offers a new conceptual approach to the use of SWIR spectroscopy for the characterization the calcination of kaolin, withdrawing the need of using extensive laboratory techniques. [ABSTRACT FROM AUTHOR]

In the mining of perlite deposits, controlling the generation of fine particles and the concentration of metals is of outstanding importance to meet the environmental and market requirements. Particle size and chemical purity are conventionally manipulated during the processing of the ore to achieve high product specifications. However, the current practices do not consider a proactive approach that focuses in the in-pit characterisation of the ore that would minimise the environmental impact and optimise the mining process since its early stages. This paper presents a method for the in-pit detection of the perlite ore variability that is related to the generation of fine particles and the elevated concentration of metals. Particle size and chemical purity showed to be dependent on the mineralogical variations of the ore, specifically opal and montmorillonite. Using a portable infrared spectrometer, an index that establishes the relative proportions of these minerals in the perlite ore was created. Such index provided insight into the correlation between mineralogy, fine particles and concentration of metals. Consequently, the index could be used not only for mineralogical determination but also as a predictor of the presence of the main impurities in the perlite ore. These results can be implemented in perlite mining to reduce the generation of waste and can influence the production of high-quality perlite products. [ABSTRACT FROM AUTHOR]

Background The erosion of the early mortality advantage of elective endovascular aneurysm repair ( EVAR) compared with open repair of abdominal aortic aneurysm remains without a satisfactory explanation. Methods An individual-patient data meta-analysis of four multicentre randomized trials of EVAR versus open repair was conducted to a prespecified analysis plan, reporting on mortality, aneurysm-related mortality and reintervention. Results The analysis included 2783 patients, with 14 245 person-years of follow-up (median 5·5 years). Early (0-6 months after randomization) mortality was lower in the EVAR groups (46 of 1393 versus 73 of 1390 deaths; pooled hazard ratio 0·61, 95 per cent c.i. 0·42 to 0·89; P = 0·010), primarily because 30-day operative mortality was lower in the EVAR groups (16 deaths versus 40 for open repair; pooled odds ratio 0·40, 95 per cent c.i. 0·22 to 0·74). Later (within 3 years) the survival curves converged, remaining converged to 8 years. Beyond 3 years, aneurysm-related mortality was significantly higher in the EVAR groups (19 deaths versus 3 for open repair; pooled hazard ratio 5·16, 1·49 to 17·89; P = 0·010). Patients with moderate renal dysfunction or previous coronary artery disease had no early survival advantage under EVAR. Those with peripheral artery disease had lower mortality under open repair (39 deaths versus 62 for EVAR; P = 0·022) in the period from 6 months to 4 years after randomization. Conclusion The early survival advantage in the EVAR group, and its subsequent erosion, were confirmed. Over 5 years, patients of marginal fitness had no early survival advantage from EVAR compared with open repair. Aneurysm-related mortality and patients with low ankle : brachial pressure index contributed to the erosion of the early survival advantage for the EVAR group. Trial registration numbers: EVAR-1, ISRCTN55703451; DREAM (Dutch Randomized Endovascular Aneurysm Management), NCT00421330; ACE (Anévrysme de l'aorte abdominale, Chirurgie versus Endoprothèse), NCT00224718; OVER (Open Versus Endovascular Repair Trial for Abdominal Aortic Aneurysms), NCT00094575. [ABSTRACT FROM AUTHOR]

Soil moisture is a critical component of a wide range of human activities. Its decline correlates well with climate change. This study extends the examination of soil moisture in Victoria, Australia by the pioneering work undertaken in 1965 by G.D. Aitchinson and B.G. Richards. It examines trends in soil moisture in three, twenty-year, and six, ten-year periods from 1948–2007. This 60-year period includes a number of wet and dry periods and provides long-term trends that should be considered in assessing the impacts of climate change on land use. The study applied the Thornthwaite Moisture Index using data on rainfall, temperature, potential evapotranspiration and soil water-holding capacity from 135 Victorian weather stations. This led to the development of soil moisture zones depicting the extent of changes between time periods. The findings hold significant implications for the future of agricultural production and construction suggesting that some practices will cease or shift to different areas. Risk from bushfires may also be increased. The findings point to the importance of soil moisture as one of many important factors contributing to the resilience of complex socio-physical systems. [ABSTRACT FROM PUBLISHER]

The time trade-off method was incorporated into a study of valuation of health states following treatment for breast cancer. A major aim of the work was to determine whether different groups give different valuations. The time trade-off technique was simple and quick to administer, acceptable to subjects, and produced different values in different groups. Age and sex of valuers had some influence: the most striking differences were found between women who had experienced breast cancer and those who had not. The time trade-off method has considerable potential in health state valuation. The choice of valuers needs to be further explored. [ABSTRACT FROM AUTHOR]

Background Implementation of the National Health Service abdominal aortic aneurysm ( AAA) screening programme ( NAAASP) for men aged 65 years began in England in 2009. An important element of the evidence base supporting its introduction was the economic modelling of the long-term cost-effectiveness of screening, which was based mainly on 4-year follow-up data from the Multicentre Aneurysm Screening Study ( MASS) randomized trial. Concern has been expressed about whether this conclusion of cost-effectiveness still holds, given the early performance parameters, particularly the lower prevalence of AAA observed in NAAASP. Methods The existing published model was adjusted and updated to reflect the current best evidence. It was recalibrated to mirror the 10-year follow-up data from MASS; the main cost parameters were re-estimated to reflect current practice; and more robust estimates of AAA growth and rupture rates from recent meta-analyses were incorporated, as were key parameters as observed in NAAASP (attendance rates, AAA prevalence and size distributions). Results The revised and updated model produced estimates of the long-term incremental cost-effectiveness of £5758 (95 per cent confidence interval £4285 to £7410) per life-year gained, or £7370 (£5467 to £9443) per quality-adjusted life-year ( QALY) gained. Conclusion Although the updated parameters, particularly the increased costs and lower AAA prevalence, have increased the cost per QALY, the latest modelling provides evidence that AAA screening as now being implemented in England is still highly cost-effective. [ABSTRACT FROM AUTHOR]

Understanding how black holes accrete and supply feedback to their environment is one of the outstanding challenges of modern astrophysics. Swift J1910.2-0546 is a candidate black hole low-mass X-ray binary that was discovered in 2012 when it entered an accretion outburst. To investigate the binary configuration and the accretion morphology, we monitored the evolution of the outburst for ≃3 months at X-ray, UV, optical (B, V, R, I), and near-infrared (J, H, K) wavelengths using Swift and SMARTS. The source evolved from a hard to a soft X-ray spectral state with a relatively cold accretion disk that peaked at ≃0.5 keV. A Chandra/HETG spectrum obtained during this soft state did not reveal signatures of an ionized disk wind. Both the low disk temperature and the absence of a detectable wind could indicate that the system is viewed at relatively low inclination. The multi-wavelength light curves revealed two notable features that appear to be related to X-ray state changes. First, a prominent flux decrease was observed in all wavebands ≃ 1-2 weeks before the source entered the soft state. This dip occurred in (0.6-10 keV) X-rays ≃ 6 days later than at longer wavelengths, which could possibly reflect the viscous timescale of the disk. Second, about two weeks after the source transitioned back into the hard state, the UV emission significantly increased while the X-rays steadily decayed. We discuss how these observations may reflect changes in the accretion morphology, perhaps related to the quenching/launch of a jet or the collapse/recovery of a hot flow. [ABSTRACT FROM AUTHOR]

Compact, steady jets are observed in the near infrared and radio bands in the hard state of Galactic black hole transients as their luminosity decreases and the source moves toward a quiescent state. Recent radio observations indicate that the jets turn off completely in the soft state; therefore, multiwavelength monitoring of black hole transients is essential to probe the formation of jets. In this work, we conducted a systematic study of all black hole transients with near infrared and radio coverage during their outburst decays. We characterized the timescales of changes in X-ray spectral and temporal properties and also in near infrared and/or in radio emission. We confirmed that state transitions occur in black hole transients at a very similar fraction of their respective Eddington luminosities. We also found that the near infrared flux increase that could be due to the formation of a compact jet is delayed by a time period of days with respect to the formation of a corona. Finally, we found a threshold disk Eddington luminosity fraction for the compact jets to form. We explain these results with a model such that the increase in the near infrared flux corresponds to a transition from a patchy, small-scale height corona along with an optically thin outflow to a large-scale height corona that allows for collimation of a steady compact jet. We discuss the timescale of jet formation in terms of transport of magnetic fields from the outer parts of the disk, and we also consider two alternative explanations for the multiwavelength emission: hot inner accretion flows and irradiation. [ABSTRACT FROM AUTHOR]

We present multi-epoch optical observations of the blazar 3C 454.3 (z = 0.859) from 2008 August through 2011 December, using the Small and Medium Aperture Research Telescope System Consortium 1.5 m + RCSpectrograph and 1.3 m + ANDICAM in Cerro Tololo, Chile. The spectra reveal that the broad emission lines Mg II, Hβ, and Hγ are far less variable than the optical or γ-ray continuum. Although the γ-rays varied by a factor of 100 above the EGRET era flux, the lines generally vary by a factor of two or less. Smaller variations in the γ-ray flux did not produce significant variation in any of the observed emission lines. Therefore, to first order, the ionizing flux from the disk changes only slowly during large variations of the jet. However, two exceptions in the response of the broad emission lines are reported during the largest γ-ray flares in 2009 December and 2010 November, when significant deviations from the mean line flux in Hγ and Mg II were observed. Hγ showed a maximum 3σ and 4σ deviation in each flare, respectively, corresponding to a factor of 1.7 and 2.5 increase in flux. Mg II showed a 2σ deviation in both flares; no variation was detected in Hβ during either flare. These significant deviations from the mean line flux also coincide with 7 mm core ejections reported previously (Jorstad et al.). The correlation of the increased emission line flux with millimeter core ejections and γ-ray, optical, and ultraviolet flares suggests that the broad-line region extends beyond the γ-emitting region during the 2009 and 2010 flares. [ABSTRACT FROM AUTHOR]

Galactic black hole transients show many interesting phenomena during outburst decays. We present simultaneous X-ray (RXTE, Swift, and INTEGRAL), and optical/near-infrared (O/NIR) observations (SMARTS) of the X-ray transient XTE J1752-223 during its outburst decay in 2010. The multiwavelength observations over 150 days in 2010 cover the transition from soft to hard spectral state. We discuss the evolution of radio emission with respect to the O/NIR light curve which shows several flares. One of those flares is bright and long, starting about 60 days after the transition in X-ray timing properties. During this flare, the radio spectral index becomes harder. Other smaller flares occur along with the X-ray timing transition, and also right after the detection of the radio core. We discuss the significances of these flares. Furthermore, using the simultaneous broadband X-ray spectra including INTEGRAL, we find that a high energy cut-off with a folding energy near 250 keV is necessary around the time that the compact jet is forming. The broadband spectrum can be fitted equally well with a Comptonization model. In addition, using photoelectric absorption edges in the XMM-Newton Reflection Grating Spectrometer X-ray spectra and the extinction of red clump giants in the direction of the source, we find a lower limit on the distance of >5 kpc. [ABSTRACT FROM AUTHOR]

Background: The long-term effects of abdominal aortic aneurysm (AAA) screening were investigated in extended follow-up from the UK Multicentre Aneurysm Screening Study (MASS) randomized trial. Methods: A population-based sample of men aged 65-74 years were randomized individually to invitation to ultrasound screening (invited group) or to a control group not offered screening. Patients with an AAA (3·0 cm or larger) detected at screening underwent surveillance and were offered surgery after predefined criteria had been met. Cause-specific mortality data were analysed using Cox regression. Results: Some 67 770 men were enrolled in the study. Over 13 years, there were 224 AAA-related deaths in the invited group and 381 in the control group, a 42 (95 per cent confidence interval 31 to 51) per cent reduction. There was no evidence of effect on other causes of death, but there was an overall reduction in all-cause mortality of 3 (1 to 5) per cent. The degree of benefit seen in earlier years of follow-up was slightly diminished by the occurrence of AAA ruptures in those with an aorta originally screened normal. About half of these ruptures had a baseline aortic diameter in the range 2·5-2·9 cm. It was estimated that 216 men need to be invited to screening to save one death over the next 13 years. Conclusion: Screening resulted in a reduction in all-cause mortality, and the benefit in AAA-related mortality continued to accumulate throughout follow-up. Registration number: ISRCTN37381646 (http://www.controlled-trials.com). Copyright © 2012 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

We present the time variability properties of a sample of six blazars, AO0235+164, 3C 273, 3C 279, PKS 1510-089, PKS 2155-304, and 3C 454.3, at optical-IR frequencies as well as γ-ray energies. These observations were carried out as a part of the Yale/SMARTS program during 2008-2010 that has followed the variations in emission of the bright Fermi Large Area Telescope monitored blazars in the southern sky with closely spaced observations at BVRJK bands. We find that the optical-near IR variability properties are remarkably similar to those at the γ-ray energies. The discrete auto-correlation functions of the variability of these six blazars at optical-IR and γ-ray energies do not show any periodicity or characteristic timescale. The power spectral density (PSD) functions of the R-band variability of all six blazars are fit well by simple power-law functions with negative slopes such that there is higher amplitude variability on longer timescales. No clear break is identified in the PSD of any of the sources. The average slope of the PSD of R-band variability of these blazars is similar to what was found by the Fermi team for the γ-ray variability of a larger sample of bright blazars. This is consistent with leptonic models where the optical-IR and γ-ray emission is generated by the same population of electrons through synchrotron and inverse Compton processes, respectively. The prominent flares present in the optical-IR as well as the γ-ray light curves of these blazars are predominantly symmetric, i.e., have similar rise and decay timescales, indicating that the long-term variability is dominated by the crossing time of radiation or a disturbance through the emission region rather than by the acceleration or energy-loss timescales of the radiating electrons. For the blazar 3C 454.3, which has the highest-quality light curves, the total energy output, the ratio of γ-ray to optical energy output, and the γ-ray versus optical flux relation differ in the six individual flares observed between 2009 August and December. The results are consistent with the location of a large γ-ray outburst in 3C 454.3 during 2009 December being in the jet at ~18 pc from the central engine. This poses strong constraints on the models of high-energy emission in the jets of blazars. [ABSTRACT FROM AUTHOR]

Internet content has become interactive; new tools can help clinicians market their practice and provide evidence-based care. Many of these tools are free or low cost and are easily mastered using simple video tutorials found on the Internet. This article highlights the uses of e-mail, social networking, smartphones, RSS feeds, social bookmarking, and collaborative Web 2.0 tools in clinical practice. [ABSTRACT FROM AUTHOR]

Background: Adherence to lipid-lowering therapy in clinical practice is less than ideal. Analysis of registry data has indicated that this is associated with poor outcomes. The objective of the present analysis was to assess the impact of high adherence to drug (defined as > 80% of days covered), compared with low adherence to drug (< 50% of days covered) in terms of risk of events and long-term economic consequences. Design: Open-label follow up of a randomised placebo-controlled trial in hypertensive patients. Methods: Cox proportional hazards and Poisson regression models were used to assess the hazard ratio of patients with high adherence compared with low adherence while controlling for cardiovascular risk. A Markov model was used to predict the long-term costs and health outcomes associated with poor adherence during the follow-up period. Results: Both statistical models indicated that high adherence is associated with improved prognosis [Cox model: 0.75; 95% confidence interval (CI): 0.56–0.98, Poisson model hazard ratio: 0.73; 95% CI: 0.58–0.98]. Discounted at 3.5% per year, the Markov model predicts that as a consequence of higher adherence during the follow-up period, costs would be higher (£1689 per patient compared with £1323 per patient) because of higher drug costs, but the projected survival and quality-adjusted survival (QALY) would also be longer (10.83 compared with 10.81 life years and 8.13 compared with 8.11 QALYs). Conclusion: Given the higher risk of cardiovascular events associated with low adherence shown here, measures to improve adherence are an important part of the prevention of cardiovascular disease. [ABSTRACT FROM AUTHOR]

GX 339−4 has been one of the key sources for unravelling the accretion ejection coupling in accreting stellar mass black holes. After a long period of quiescence between 1999 and 2002, GX 339−4 underwent a series of four outbursts that have been intensively observed by many ground-based observatories [radio/infrared (IR)/optical] and satellites (X-rays). Here, we present results of these broad-band observational campaigns, focusing on the optical–IR (OIR)/X-ray flux correlations over the four outbursts. We found tight OIR/X-ray correlations over four decades with the presence of a break in the IR/X-ray correlation in the hard state. This correlation is the same for all four outbursts. This can be interpreted in a consistent way by considering a synchrotron self-Compton origin of the X-rays in which the break frequency varies between the optically thick and thin regime of the jet spectrum. We also highlight the similarities and differences between optical/X-ray and IR/X-ray correlations which suggest a jet origin of the near-IR emission in the hard state while the optical is more likely dominated by the blackbody emission of the accretion disc in both hard and soft state. However, we find a non-negligible contribution of 40 per cent of the jet emission in the V band during the hard state. We finally concentrate on a soft-to-hard state transition during the decay of the 2004 outburst by comparing the radio, IR, optical and hard X-rays light curves. It appears that unusual delays between the peak of emission in the different energy domains may provide some important constraints on jet formation scenario. [ABSTRACT FROM AUTHOR]

Background: ASCOT (Anglo-Scandinavian Cardiac Outcomes Trial) showed in hypertensive patients that blood pressure-lowering treatment with an amlodipine-based regimen reduces events compared with an atenolol-based regimen and that atorvastatin was more effective than placebo.Objective: To assess the cost effectiveness of four alternative treatment strategies in patients with hypertension and three or more cardiovascular risk factors in the UK (from the UK NHS perspective) or Sweden (from the societal perspective): amlodipine-based plus atorvastatin, atenolol-based plus atorvastatin, amlodipine-based alone and atenolol-based alone.Methods: Based on the trial data, a Markov model was constructed where the risk of myocardial infarction, revascularization procedures and stroke and the long-term costs, quality of life and mortality associated with these events were estimated. Transition probabilities and costs (euro, 2007 values) were based on the patient-level trial data. Outcomes were reported as life-years gained and QALYs. In the latter case, utility reduction from events was based on a substudy in ASCOT patients. Treatment was applied for the duration of the lipid-lowering arm of the trial (3 years) and patients were then followed to the end of their life.Results: Amlodipine-based therapy plus atorvastatin was the most expensive but also most effective treatment. Compared with amlodipine-based therapy alone, the cost to gain one QALY was euro 11,965 in the UK and euro 8,591 in Sweden. The incremental cost effectiveness of amlodipine-based therapy compared with atenolol-based therapy was euro 9,548 and euro 3,965 per QALY gained in the UK and Sweden, respectively. Atenolol-based therapy plus atorvastatin was eliminated through extended dominance. Applying the threshold values used by the National Institute for Health and Clinical Excellence (NICE) and the Swedish National Board of Health and Welfare, a combination of amlodipine-based therapy and atorvastatin appears to be cost effective in patients with hypertension and three or more additional risk factors. [ABSTRACT FROM AUTHOR]

Objectives: This study assesses the impact of the English National Health Service (NHS) Health Technology Assessment (HTA) program using the "payback" framework.Methods: A survey of lead investigators of all research projects funded by the HTA program 1993--2003 supplemented by more detailed case studies of sixteen projects.Results: Of 204 eligible projects, replies were received from 133 or 65 percent. The mean number of peer-reviewed publications per project was 2.9. Seventy-three percent of projects claimed to have had had an impact on policy and 42 percent on behavior. Technology Assessment Reports for the National Institute for Health and Clinical Excellence (NICE) had fewer than average publications but greater impact on policy. Half of all projects went on to secure further funding. The case studies confirmed the survey findings and indicated factors associated with impact.Conclusions: The HTA program performed relatively well in terms of "payback." Facilitating factors included the program's emphasis on topics that matter to the NHS, rigorous methods and the existence of "policy customers" such as NICE. [ABSTRACT FROM AUTHOR]

Background: Evidence suggests that an early interventional strategy for patients with non-ST-elevation acute coronary syndrome (NSTE-ACS) can improve health outcomes but also increase costs when compared with a conservative strategy. Objective: The aim of this study was to assess the cost- effectiveness of an early interventional strategy in different risk groups from a UK health-service perspective. Design: Decision-analytic model based on randomised clinical trial data. Main outcome measures: Costs in UK Sterling at 2003/ 2004 prices and quality-adjusted life years IQALYs) combined into an incremental cost-effectiveness ratio. Methods: Data from the third Randomised Intervention Trial cf unstable Angina (RITA 31 was employed to estimate rates of cardiovascular death and myocardial infarction, costs and health-related quality of life. Cost- effectiveness was estimated over patients' lifetimes within the decision-analytic model. Results: The mean incremental cost per QALY gained for an early interventional strategy was approximately £55 000, £22 000 and £12000 for patients at low, intermediate and high risk, respectively. The early interventional strategy is approximately 1%, 35% and 95% likely to be cost-effective for patients at low, intermediate and high risk, respectively, at a threshold of £20 000 per QALY. The cost-effectiveness of early intervention in low- risk patients is sensitive to assumptions about the duration of the treatment effect. Conclusion: An early interventional strategy in patients presenting with NSTE-ACS is likely to be considered cost- effective for patients at high and intermediate risk, but this is less likely to be the case for patients at low risk. [ABSTRACT FROM AUTHOR]

The article discusses the results of a study on the cost-effectiveness of endovascular abdominal aortic aneurysm repair (EVAR). It reveals that older patients should benefit more from EVAR in terms of absolute risk reduction, however, EVAR will be cost-effective in this group only if patients maintain such early survival advantage over open surgery.

Background: Patients with refractory angina have significant morbidity. This study aimed to compare two of the treatment options, Spinal Cord Stimulation (SCS) and Percutaneous Myocardial Laser Revascularisation (PMR) in terms of clinical outcomes and cost-effectiveness. Methods: Eligible patients were randomised to PMR or SCS and followed up for exercise tolerance time (ETT), Canadian Cardiovascular Society (CCS) classification and the quality of life measures SF-36, Seattle Angina Questionnaire and the EuroQoL at 3, 12 and 24 months. Utilities were calculated using the EQ-5D and these and costs were compared between groups. The incremental cost-effectiveness ratio (ICER) per QALY for SCS compared to PMR was also calculated. Results: At 24 months post-randomisation, patients that had SCS and PMR had similar ETT (mean difference 0.05, 95% CI -2.08, 2.18, p = 0.96) and there was no difference in CCS classification or quality of life outcomes. The difference in overall mean costs when comparing SCS to PMR was GBP5,520 (95% CI GBP1,966 to GBP8,613; p < 0.01) and the ICER of using SCS was GBP46,000 per QALY. Conclusion: Outcomes after SCS did not differ appreciably from those after PMR, with the former procedure being less cost-effective as currently applied. Larger studies could clarify which patients would most benefit from SCS, potentially increasing cost-effectiveness. Trial registration: Current Controlled Trials ISRCTN09648950 [ABSTRACT FROM AUTHOR]

Objective: To provide reliable estimates of the long-term cost-effectiveness of abdominal aortic aneurysm screening in men. Methods: A Markov health economic decision model for screening is described and extrapolated to 30 years. The strategy modelled involves a one-off scan at age 65 years, with annual and three-monthly follow-up scans for small and medium aneurysms, respectively. Referral for elective surgery occurs at an aortic diameter of 5.5 cm. Model parameters are estimated from patient-level data from the UK Multi-centre Aneurysm Screening Study. Model structure is validated on this trial's data, and input parameter uncertainty is addressed by probabilistic sensitivity analysis. Costs and life-years gained are obtained for both screening and no systematic screening strategies. Results: Cost-effectiveness improves dramatically when considered over longer timescales. Taking a 30-year perspective, screening for abdominal aortic aneurysms in men is highly cost-effective at £2320 per life-year gained (95% uncertainty interval: £1600 to £4240). Adjusting life-years for the age-specific health-related quality of life experienced in this population gave a figure of £2970 (95% uncertainty interval: £2030 to £5430) per quality-adjusted life-year gained. The additional cost of screening the UK male population is estimated to be £19 m per year. Conclusions: The long-term cost-effectiveness of screening for abdominal aortic aneurysms in men is highly attractive and this evidence provides further support for a national screening programme in the UK. [ABSTRACT FROM AUTHOR]

The optical/near-infrared (OIR) region of the spectra of low-mass X-ray binaries (XBs) appears to lie at the intersection of a variety of different emission processes. In this paper we present quasi-simultaneous OIR–X-ray observations of 33 XBs in an attempt to estimate the contributions of various emission processes in these sources, as a function of X-ray state and luminosity. A global correlation is found between OIR and X-ray luminosity for low-mass black hole candidate XBs (BHXBs) in the hard X-ray state, of the form . This correlation holds over eight orders of magnitude in LX and includes data from BHXBs in quiescence and at large distances [Large Magellanic Cloud (LMC) and M31]. A similar correlation is found in low-mass neutron star XBs (NSXBs) in the hard state. For BHXBs in the soft state, all the near-infrared (NIR) and some of the optical emissions are suppressed below the correlation, a behaviour indicative of the jet switching off/on in transition to/from the soft state. We compare these relations to theoretical models of a number of emission processes. We find that X-ray reprocessing in the disc and emission from the jets both predict a slope close to 0.6 for BHXBs, and both contribute to the OIR in BHXBs in the hard state, the jets producing ∼90 per cent of the NIR emission at high luminosities. X-ray reprocessing dominates the OIR in NSXBs in the hard state, with possible contributions from the jets (only at high luminosity) and the viscously heated disc. We also show that the optically thick jet spectrum of BHXBs extends to near the K band. OIR spectral energy distributions of 15 BHXBs help us to confirm these interpretations. We present a prediction of the behaviour of a BHXB outburst that enters the soft state, where the peak LOIR in the hard state rise is greater than in the hard state decline (the well-known hysteretical behaviour). In addition, it is possible to estimate the X-ray, OIR and radio luminosity and the mass accretion rate in the hard state quasi-simultaneously, from observations of just one of these wavebands, since they are all linked through correlations. Finally, we have discovered that the nature of the compact object, the mass of the companion and the distance/reddening can be constrained by quasi-simultaneous OIR and X-ray luminosities. [ABSTRACT FROM AUTHOR]

Aims Assessment of the impact of health research is a growing but problematic field. We examined how a combination of approaches might together inform assessment of the impact of a body of diabetes research published in 1981 and help identify factors behind success. Methods Three broad approaches were applied to the work of one team leader of acknowledged influence. Standard bibliographic analysis was complemented by a second approach which categorized the importance of the primary publications to the papers citing them, in four domains. In parallel, a third approach involved qualitative assessment using surveys, critical pathway analysis by, and interviews of, co-authors and external experts. Extending the approach incorporated key additional publications from other years. Results In 1981, the team leader published 29 papers. Citations to these 29 first generation papers varied from 1 to 76 and resulted in 799 second generation papers. Citations to these produced 12 891 third generation papers. Analysis of second generation papers suggested the cited first generation paper was thought to be of considerable or essential significance in only 9% of cases. While much research made little impact, qualitative analysis included a wealth of information, sometimes missed by standard bibliographic techniques, on where the identified research influenced important streams of clinical development. Analysis covered major research studies (such as the Diabetes Control and Complications Trial), insulin pump therapy, and career development of co-authors. Conclusions Understanding the impact of research requires multiple approaches. With refinement, these techniques could be employed more widely and potentially could inform research policy. [ABSTRACT FROM AUTHOR]

In this paper we report on the discovery of the optical counterpart to the neutron star soft X-ray transient (SXT) XTE J1709–267 at anR-band magnitude ofand, in outburst and quiescence, respectively. We further report the detection of type I X-ray bursts inRXTEdata obtained during an outburst of the source in 2002. These bursts show a precursor before the onset of the main burst event, reminiscent of photospheric radius expansion bursts. Sifting through the archivalRXTEdata for the burster 4U 1636–53, we found a nearly identical burst with precursor in 4U 1636–53. A comparison of this burst to true photospheric radius expansion bursts in 4U 1636–53 leads us to conclude that these bursts-with-precursor do not reach the Eddington limit. Nevertheless, from the burst properties we can derive that the distance to XTE J1709–267 is consistent with the distance of the Globular Cluster NGC 6293. We further report on the analysis of a 22.7 ks observation of XTE J1709–267 obtained with theChandrasatellite when the source was in quiescence. We found that the source has a soft quiescent spectrum which can be fit well by an absorbed black body or neutron star atmosphere model. A power law contributes less than∼20 per cent to the 0.5–10 keV unabsorbed flux of. This flux is only slightly lower than the flux measured right after the outburst in 2002. This is in contrast to the recent findings for MXB 1659–29, where the quiescent source flux decreased gradually by a factor of∼7–9 over a period of 18 months. Finally, we compared the fractional power–law contribution to the unabsorbed 0.5–10 keV luminosity for neutron star SXTs in quiescence for which the distance is well-known. We find that the power-law contribution is low only when the source quiescent luminosity is close to. Both at higher and lower values the power–law contribution to the 0.5–10 keV luminosity increases. We discuss how models for the quiescent X-ray emission can explain these trends. [ABSTRACT FROM AUTHOR]

Objectives: To compare initial and one year costs of coronary artery bypass grafting (CABG) versus percutaneous coronary intervention (PCI) in the stent or surgery trial. Design: Prospective, unblinded, randomised trial. Setting: Multicentre study. Patients: 988 patients with multivessel disease. Interventions: CABG and stent assisted PCI. Main outcome measures: Initial hospitalisation and one year follow up costs. Results: At one year mortality was 2.5% in the PCI arm and 0.8% in the CABG arm (p = 0.05). There was no difference in the composite of death or Q wave myocardial infarction (6.9% for PCI v 8. 1% for CABG, p = 0.49). There were more repeat revasculorisations with PCI (17.2% v 4.2% For CABG). There was no significant difference in utility between arms at six months or at one year. Quality adjusted life years were similar 0.6938 for PCI v 0.6954 for PCI, Δ = 0.00154, 95% confidence interval (CI) -0.0242 to 0.0273). Initial length of stay was longer with CABG (12.2 v 5.4 days with PCI, p < 0.0001) and initial hospitalization costs were higher (£7321 v £3884 for PCI, Δ = £ 3437, 95% CI £3040 to £3848). At one year the cost difference narrowed but costs remained higher for CABG (£8905 v £6296 for PCI, Δ = £2609, 95% CI £1769 to £3314). Conclusions: Over one year, CABG was more expensive and offered greater survival than PCI but little added benefit in terms of quality adjusted life years. The additional cost of CABG can be justified only if it offers continuing benefit at no further increase in cost relative to PCI over several years. [ABSTRACT FROM AUTHOR]

ABSTRACT Optical spectroscopic observations of GX 339-4 were carried out between 1998 May (X-ray high state) and 1999 May (X-ray low state) over seven epochs. The equivalent width of Hα increased during the high state and then decreased during the low state. The equivalent width of He iiλ4686 decreased over both states. The full-width at half-maximum of Hα, Hβ, He iiλ4686 and the Bowen blend increased from 1998 to 1999, indicating that the emission-line regions moved closer to the compact object. Hβ shows a redshifted absorption feature at λ4880 at all epochs. This line remains unidentified. Analysis of individual spectra from 1998 May 28–31 shows modulation of the radial velocities, equivalent width and V/R ratios of Hα on the 14.86-h orbital period. The equivalent width of He iiλ4686 also varies on the orbital period. The semi-amplitude of the Hα radial velocities is K[sub 1]= 14 km s[sup -1] . Hence the mass function = 2 × 10[sup -4] M[sub ⊙] . [ABSTRACT FROM AUTHOR]

Background: A study was undertaken to investigate the preferences of patients with asthma for attributes or characteristics associated with treatment for their asthma and to investigate the extent to which such preferences may differ between patient subgroups.Methods: The economic technique of conjoint analysis (CA) was used to investigate patients' strength of preference for several key attributes associated with services for the treatment of asthma. A CA questionnaire was administered to two groups of asthma outpatients aged 18 years or older, 150 receiving conventional treatment at Whipps Cross Hospital (WC) and 150 receiving homeopathic treatment at the Royal London Homoeopathic Hospital (RL).Results: An overall response rate of 47% (n=142) was achieved. Statistically significant attributes in influencing preferences for both the WC and RL respondents were (1) the extent to which the doctor gave sufficient time to listen to what the patient has to say, (2) the extent to which the treatment seemed to relieve symptoms, and (3) the travel costs of attending for an asthma consultation. The extent to which the doctor treated the patient as a whole person was also a statistically significant attribute for the RL respondents.Conclusions: This study has shown that aspects associated with the process of delivery of asthma services are important to patients in addition to treatment outcomes. The homeopathic respondents expressed stronger preferences for the doctor to treat them as a whole person than the patients receiving conventional treatment. Overall, the preferences for the attributes included in the study were similar for both groups. [ABSTRACT FROM AUTHOR]

A shortage of donor liver grafts unfortunately results in approximately 10% of patients dying whilst listed for a liver transplant in Europe and the United States. Thus it is imperative that all available organs are used as efficiently as possible. This paper reports upon the application of a simulation modelling approach to assess the impact of several alternative allocation policies upon the cost effectiveness of this technology at one liver transplant centre in the UK. The impact of changes in allocation criteria on the estimated net life expectancy, average net costs and overall cost effectiveness of the transplantation programme were evaluated. The incremental cost effectiveness ratio (ICER) for the base case allocation policy, based upon the time spent on the waiting list (i.e., longest wait first) was 11,557 pounds sterling at 1999 prices. The ICERs associated with an allocation policy based upon age (lowest age first), and an allocation policy based upon the severity of the pre-transplant condition of the patient (with most severely ill patients given a lower priority) were lower than the base case at 10,424 pounds sterling and 9,077 pounds sterling, respectively. The results of this modelling study suggest that the overall cost effectiveness of the liver transplantation programme could be improved if the current allocation policy were modified to give more weight to the age of the patient and the reduced chances of success of the most severely ill patients. [ABSTRACT FROM AUTHOR]

Examines the status of left ventricular assist device (LVAD) technology in Great Britain. Factors contributing to the problems inherent in the evaluation of low volume, high cost and potentially life-saving surgical interventions; Role of medical devices in providing medical assistance to heart failure; Evaluation of LVAD as therapy for patients unsuitable for heart transplantation.

The article discusses issues related to the economically justified treatment for cancer. Patients go through different medical treatments like radiation, and curative or palliative chemotherapy, but these treatments do not provide much benefit to the patients. Oncologists use chemotherapy for patients with advanced cancer who are unlikely to benefit. Before applying costly measures and making a decision, clinicians need to analyze and consider the condition of a patient carefully.

One hundred and forty-two (142) halo nevi were reviewed. For 66 cases the diagnosis of halo nevus was made both clinically and pathologically, and for 76 cases the diagnosis was based on histological grounds alone. The nevi were classified by type and by degree of atypia. Of the 142 nevi, all were compound, junctional, or intradermal nevi except for one case of a Spitz nevus and two cases that could not be further classified. For those with a clinicopathological diagnosis of halo nevus, 11% exhibited moderate atypia; 16% exhibited minimal atypia to only focally moderate atypia; 24% minimal atypia; and 49% exhibited no significant atypia. For those cases where the diagnosis was pathological only, there was also a broad spectrum of atypia identified, with 8% exhibiting focally severe or severe atypia. This study supports the concept that the halo nevus should not be regarded as a single clinicopathological entity, but rather that the halo phenomenon occurs in a wide spectrum of nevus types exhibiting a wide spectrum of histological atypia. The pathologist is therefore encouraged to classify halo nevi on the basis of the nevus cell population alone, using whatever classification normally utilized. [ABSTRACT FROM AUTHOR]

The objectives of this study were to report on the health-related quality of life (QoL) experienced by patients following liver transplantation and to investigate the factors associated with its variation. A questionnaire comprising the SF-36 and EuroQol EQ-5D instruments was sent by post to 147 patients who had received a liver transplant, indicated by a chronic liver disease, in the previous 8 years. The scores of the respondents were compared to population norm scores. The variation in both the SF-36 and EQ-5D scores was explored. Many liver transplant patients experienced most satisfactory QoL levels post- transplantation although, in general terms, the levels were poorer than those seen in the general population. The variation in the post-transplant health-related QoL scores was found to be associated with a number of pre-transplant factors: disease severity (proxied by Child Pugh class), disease duration at the time of transplantation and liver transplant history (whether the patient had received a single or multiple transplants). In making clinical decisions about the use of transplantation for chronic liver diseases, consideration should be given to the key factors likely to affect subsequent health-related QoL. [ABSTRACT FROM AUTHOR]

The objectives of this study were to report on the health-related quality of life (QoL) experienced by patients following liver transplantation and to investigate the factors associated with its variation. A questionnaire comprising the SF-36 and EuroQol EQ-5D instruments was sent by post to 147 patients who had received a liver transplant, indicated by a chronic liver disease, in the previous 8 years. The scores of the respondents were compared to population norm scores. The variation in both the SF-36 and EQ-5D scores was explored. Many liver transplant patients experienced most satisfactory QoL levels post-transplantation although, in general terms, the levels were poorer than those seen in the general population. The variation in the post-transplant health-related QoL scores was found to be associated with a number of pre-transplant factors: disease severity (proxied by Child Pugh class), disease duration at the time of transplantation and liver transplant history (whether the patient had received a single or multiple transplants). In making clinical decisions about the use of transplantation for chronic liver diseases, consideration should be given to the key factors likely to affect subsequent health-related QoL. [ABSTRACT FROM AUTHOR]