The cost-effectiveness of an early interventional strategy in non-ST-elevation acute coronary syndrome based on the RITA 3 trial

The published version of the aritcle can be found at the link below.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 (QALYs) combined into an incremental cost-effectiveness ratio.Methods: Data from the third Randomised Intervention Trial of unstable Angina (RITA 3) 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 £55000, £22000 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 £20000 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

Asymptotically exact photonic approximations of chiral symmetric topological tight-binding models

Topological photonic edge states, protected by chiral symmetry, are attractive for guiding wave energy as they can allow for more robust guiding and greater control of light than alternatives; however, for photonics, chiral symmetry is often broken by long-range interactions. We look to overcome this difficulty by exploiting the topology of networks, consisting of voids and narrow connecting channels, formed by the spaces between closely spaced perfect conductors. In the limit of low frequencies and narrow channels, these void-channel systems have a direct mapping to analogous discrete mass-spring systems in an asymptotically rigorous manner and therefore only have short-range interactions. We demonstrate that topological tight-binding models that are protected by chiral symmetries, such as the SSH model and square-root semimetals, are reproduced for these void-channel networks with appropriate boundary conditions. We anticipate, moving forward, that this paper provides a basis from which to explore continuum photonic topological systems, in an asymptotically exact manner, through the lens of a simplified tight-binding model

Effects of fire on the hydrology, biogeochemistry, and ecology of peatland river systems

Peatlands are found around the world and cover ~3.4% of the Earth’s surface. In the UK, peatlands cover 17.2% or ~1.58 Mha of the land surface and occur mainly in upland areas covering the headwaters of most major British rivers. However, large areas are now subject to prescribed vegetation burning despite policy guidance that recommends a strong presumption against burning deep blanket peat. Wildfires occur sporadically but are forecast to increase in frequency in the future. This paper provides a synthesis of current knowledge about how UK peatland-dominated river catchments respond to fires caused by prescribed vegetation burning and uncontrolled wildfire. We provide insight into the effects of fire on the hydrology, biogeochemistry, and biota of peatland river ecosystems, and the peatland-soil-driven controls on these effects at the catchment-scale. Burning increases the depth to water table and water-table variability, although some small-scale studies indicate shallower water table in some places. More work is needed on fire effects on peatland river flow, but recent results suggest a complex response with smaller flow peaks for burned systems associated with most rainfall events, but enhanced peaks compared to unburned systems for the top quintile of rainfall events with the largest total rain. Evidence from biogeochemical studies suggests that fire leads to increased dissolved organic C concentrations in rivers. River biota responses primarily include significant reductions in the density of grazing mayflies but increases among detritivores including Chironomidae and Baetis mayflies. We provide a conceptual synthesis that links the main responses of terrestrial and aquatic systems to fire, and we summarize some major research gaps that should be prioritized to inform future policy around peatland management

Extensive winter subglacial water storage beneath the Greenland Ice Sheet

This is the final version of the article. Available from AGU via the DOI in this record.Surface meltwater that reaches the base of the Greenland Ice Sheet exerts a fundamental impact on ice flow, but observations of catchment-wide movement and distribution of subglacial water remain limited. Using radar-sounding data from two seasons, we identify the seasonal distribution of subglacial water in western Greenland. Our analysis provides evidence of widespread subglacial water storage beneath Greenland in the wintertime. The winter storage is located primarily on bedrock ridges with higher bed elevations in excess of 200 m. During the melt season water moves to the subglacial troughs. This inverse relationship with topography indicates that the material properties of the glacier bed strongly influence subglacial drainage development. Both the spatial variations in bed properties and the initial state of the subglacial hydrology system at the start of the melt season lead to differing glacier dynamical responses to surface melting across the Greenland Ice Sheet.W.C. is a recipient of the NASA Earth and Space Science Fellowship. D.M.S. is supported by a grant from the NASA Cryospheric Sciences Program. H.S. is supported by grants from the NASA Cryospheric Sciences and Sea Level Rise Programs. T.T.C and R.E.B are supported by grants from National Science Foundation (NSF) and NASA Cryospheric Sciences. S.P. is supported by the Natural Environment Research Council’s Centre for Polar Observatio

Measuring Accuracy of Automated Parsing and Categorization Tools and Processes in Digital Investigations

This work presents a method for the measurement of the accuracy of evidential artifact extraction and categorization tasks in digital forensic investigations. Instead of focusing on the measurement of accuracy and errors in the functions of digital forensic tools, this work proposes the application of information retrieval measurement techniques that allow the incorporation of errors introduced by tools and analysis processes. This method uses a `gold standard' that is the collection of evidential objects determined by a digital investigator from suspect data with an unknown ground truth. This work proposes that the accuracy of tools and investigation processes can be evaluated compared to the derived gold standard using common precision and recall values. Two example case studies are presented showing the measurement of the accuracy of automated analysis tools as compared to an in-depth analysis by an expert. It is shown that such measurement can allow investigators to determine changes in accuracy of their processes over time, and determine if such a change is caused by their tools or knowledge.Comment: 17 pages, 2 appendices, 1 figure, 5th International Conference on Digital Forensics and Cyber Crime; Digital Forensics and Cyber Crime, pp. 147-169, 201

Health and safety of the older worker

This is the author's pre-copyedited accepted manuscript. The final published article is available from the link below. Copyright @ 2012 The Authors.Background - In the UK, increasing numbers of paid employees are over 60 years with further increases expected as the state pension age rises. Some concern surrounds possible increased work-related illness and accidents for people working beyond the age of 60. Aims - To identify the available evidence for health and safety risks of workers over age 60 years with respect to factors associated with injuries and accidents. Methods - Databases searched included PUBMED, OSHUpdate, National Institute for Occupational Safety and Health (NIOSHTIC-2), SafetyLit, the UK The Health and Safety Executive (HSELINE) and the Canadian Centre for Occupational Health and Safety until December 2009. Inclusion criteria were workers aged over 60 years. Findings were grouped into occupational accidents and injuries and individual and workplace factors that may have influenced risk of injury to the over-60s. Results - Very little direct evidence was found concerning safety practices and health risks of workers over age 60. Some safety risks were associated with specific physical declines such as age-related hearing loss. Overall, these workers had fewer accidents and injuries but these were more likely to be serious or fatal when they occurred. There was no strong evidence that work patterns, including shift work or overtime, affected safety. Protective, compensatory strategies or experience may maintain safe working practices. Conclusions - Implications for health and safety risks cannot be assessed without longitudinal research on workforces with substantial numbers of workers over age 60 in order to address the healthy worker effect.Institution of Occupational Health and Safet

A piece of the puzzle: analyses of recent strandings and historical records reveal new genetic and ecological insights on New Zealand sperm whales

Cetacean strandings provide important opportunities to extend current knowledge on species or populations, particularly for species that are notoriously difficult to study, such as sperm whales Physeter macrocephalus (parāoa). Between 25 May and 9 June 2018, 13 male sperm whales stranded in Taranaki, New Zealand (NZ), with an additional male stranding 1 mo later in Clifford Bay, Marlborough. We profiled these 14 males for mitochondrial DNA (mtDNA) and carbon and nitrogen stable isotopes to examine their similarity to sperm whales from other geographic areas. Analyses of mtDNA revealed 7 haplotypes, including 1 not previously described (‘New’), and an additional haplotype (‘M’) new to NZ that had been previously reported in sperm whales of the Pacific region. Analysis of rare haplotypes found in NZ males suggested genetic links within NZ and the Southwest Pacific. Differences in stable isotope ratios indicated that, despite the close temporal proximity of these stranding events, individuals originated from at least 2 separate groups, with the whale stranded in Clifford Bay identified as being a regular visitor to Kaikōura, South Island. The analysis of stranding records in NZ dating back to 1873 indicated an increase in recorded single strandings since 1970, and a peak in single strandings in the austral summer months, but no seasonality for mass strandings. Sex predicted latitudinal location for single strandings, with 95.1% of female strandings occurring north of 42° S, fitting the general global distribution of female sperm whales limited to lower latitudes. This study provides the first temporal and spatial assessment of sperm whale strandings in NZ and highlights the need for future research on movements and genetic exchange between NZ sperm whales and sperm whales in the wider Pacific region.Publishe

Mapping mean total annual precipitation in Belgium, by investigating the scale of topographic control at the regional scale

Accurate precipitation maps are essential for ecological, environmental, element cycle and hydrological models that have a spatial output component. It is well known that topography has a major influence on the spatial distribution of precipitation and that increasing topographical complexity is associated with increased spatial heterogeneity in precipitation. This means that when mapping precipitation using classical interpolation techniques (e.g. regression, kriging, spline, inverse distance weighting, etc.), a climate measuring network with higher spatial density is needed in mountainous areas in order to obtain the same level of accuracy as compared to flatter regions. In this study, we present a mean total annual precipitation mapping technique that combines topographical information (i.e. elevation and slope orientation) with average total annual rain gauge data in order to overcome this problem. A unique feature of this paper is the identification of the scale at which topography influences the precipitation pattern as well as the direction of the dominant weather circulation. This method was applied for Belgium and surroundings and shows that the identification of the appropriate scale at which topographical obstacles impact precipitation is crucial in order to obtain reliable mean total annual precipitation maps. The dominant weather circulation is determined at 260°. Hence, this approach allows accurate mapping of mean annual precipitation patterns in regions characterized by rather high topographical complexity using a climate data network with a relatively low density and/or when more advanced precipitation measurement techniques, such as radar, aren't available, for example in the case of historical data

Greenland subglacial lakes detected by radar

This is the final version of the article. Available from AGU via the DOI in this record.Subglacial lakes are an established and important component of the basal hydrological system of the Antarctic ice sheets, but none have been reported from Greenland. Here we present airborne radio echo sounder (RES) measurements that provide the first clear evidence for the existence of subglacial lakes in Greenland. Two lakes, with areas ~8 and ~10 km2, are found in the northwest sector of the ice sheet, ~40 km from the ice margin, and below 757 and 809 m of ice, respectively. The setting of the Greenland lakes differs from those of Antarctic subglacial lakes, being beneath relatively thin and cold ice, pointing to a fundamental difference in their nature and genesis. Possibilities that the lakes consist of either ancient saline water in a closed system or are part of a fresh, modern open hydrological system are discussed, with the latter interpretation considered more likely.Funding was provided by NERC grant NE/ H020667. Additional support was provided by NASA grant NNX11AD33G and the G. Unger Vetlesen foundation

Grounding line retreat and ice discharge variability at two surging, ice shelf‐forming basins of Flade Isblink ice cap, Northern Greenland

This is the final version. Available on open access from Wiley via the DOI in this record.Data Availability Statement: The Landsat data used in this study are available from the United States Geological Survey (USGS) Earth Explorer website subject to registration. The PANGAEA earth science data repository provides access to the Sentinel-1 ice flow velocity data (https://doi.org/10.1594/PANGAEA.935651) and the Sentinel-1 radar double-difference interferograms (https://doi.org/10.1594/PANGAEA.935652).Ice discharge from Flade Isblink ice cap (NE Greenland) maintains an ice shelf at the northwestern fringe of the ice cap. The two outlet basins feeding this ice shelf surged during the late 1990s. Ice shelves are rare in Greenland and surges of ice shelf terminating glaciers even rarer. Understanding and explaining the evolution of ice mass changes in the two basins is hampered by a lack of knowledge about processes at their grounding zones. We determined, for the first time, the grounding line locations of these basins and analyzed their variability with time. We further quantified ice discharge and its variability during the period 1988–2020. We found that the grounding lines advanced slightly between 1993 and 1999 during the glacier surges, but showed overall retreats of 2.2 ± 1.3 km in basin 2 and 2.7 ± 0.9 km in basin 3 until 2019 over retrograde sloping beds. The retreats were promoted by increasing buoyancy forces due to increasing water depth, but opposing buttressing forces of the ice shelf induced a differing response of the grounding line in the two basins. Based on the observed patterns of flow and retreat, we characterized the surges as “Svalbard-type”, modified by buttressing effects of the ice shelf. We calculated total ice discharges over the study period of 1.85 ± 1.59 Gt in basin 2 and 1.38 ± 1.22 Gt in basin 3. We observed reductions in ice discharge of at least 90% after the surges, that persisted for the remainder of the period studied.Bundesministerium für Bildung und Forschung (BMBF).Deutsche Forschungsgemeinschaft (DFG)