1,013 research outputs found

    Lagrangian Decomposition of the Atlantic Ocean Heat Transport at 26.5°N

    Get PDF
    The Atlantic Meridional Overturning Circulation (AMOC) plays a critical role in the global climate system through the redistribution of heat, freshwater and carbon. At 26.5°N, the meridional heat transport has traditionally been partitioned geometrically into vertical and horizontal circulation cells; however, attributing these components to the AMOC and Subtropical Gyre (STG) flow structures remains widely debated. Using water parcel trajectories evaluated within an eddy‐rich ocean hindcast, we present the first Lagrangian decomposition of the meridional heat transport at 26.5°N. We find that water parcels recirculating within the STG account for 37% (0.36 PW) of the total heat transport across 26.5°N, more than twice that of the classical horizontal gyre component (15%). Our findings indicate that STG heat transport cannot be meaningfully distinguished from that of the basin‐scale overturning since water parcels cooled within the gyre subsequently feed the northward, subsurface limb of the AMOC

    Cost-utility Analysis of Interventions to Improve Effectiveness of Exercise Therapy for Adults with Knee Osteoarthritis::the BEEP Trial

    Get PDF
    Objectives: Evidence regarding the cost-effectiveness of enhancing physical therapy exercise programmes in order to improve outcomes for patients with knee OA remains unclear. This study investigates the cost-effectiveness of two enhanced physical therapy interventions compared with usual physical therapy care (UC) for adults with knee OA. Methods: A trial-based cost-utility analysis of individually tailored exercise (ITE) or targeted exercise adherence (TEA) compared with UC was undertaken over a period of 18 months. Patient-level costs were obtained, and effectiveness was measured in terms of quality-adjusted life years (QALYs), allowing the calculation of cost per QALY gained from a base-case UK health-care perspective. Results: The UC group was associated with lower National Health Service (NHS) costs [ITE-UC: £273.30, 95% CI: £-62.10 to £562.60; TEA-UC: £141.80, 95% CI: £-135.60 to £408.10)] and slightly higher QALY gains (ITE-UC: -0.015, 95% CI: -0.057 to 0.026; TEA-UC: -0.003, 95% CI: -0.045 to 0.038). In the base case, UC was the most likely cost-effective option (probability?<40% of ITE or TEA cost-effective at £20 000/QALY). Differences in total costs were attributable to intervention costs, number of visits to NHS consultants and knee surgery, which were higher in both ITE and TEA groups. Conclusion: This is the first economic evaluation comparing usual physical therapy care vs enhanced exercise interventions for knee OA that involves greater exercise individualization, supervision and progression or that focuses on exercise and physical activity adherence over the longer term. Our findings show that UC is likely to be the most cost-effective option. Trial registration: Current Controlled Trials ISRCTN 93634563. Trial protocol: Full details of the trial protocol can be found in the Supplementary Appendix, available with the full text of this article at http://www.biomedcentral.com/1471-2474/15/254 doi: 10.1186/1471-2474-15-254

    Survey of the quality of experimental design, statistical analysis and reporting of research using animals

    Get PDF
    For scientific, ethical and economic reasons, experiments involving animals should be appropriately designed, correctly analysed and transparently reported. This increases the scientific validity of the results, and maximises the knowledge gained from each experiment. A minimum amount of relevant information must be included in scientific publications to ensure that the methods and results of a study can be reviewed, analysed and repeated. Omitting essential information can raise scientific and ethical concerns. We report the findings of a systematic survey of reporting, experimental design and statistical analysis in published biomedical research using laboratory animals. Medline and EMBASE were searched for studies reporting research on live rats, mice and non-human primates carried out in UK and US publicly funded research establishments. Detailed information was collected from 271 publications, about the objective or hypothesis of the study, the number, sex, age and/or weight of animals used, and experimental and statistical methods. Only 59% of the studies stated the hypothesis or objective of the study and the number and characteristics of the animals used. Appropriate and efficient experimental design is a critical component of high-quality science. Most of the papers surveyed did not use randomisation (87%) or blinding (86%), to reduce bias in animal selection and outcome assessment. Only 70% of the publications that used statistical methods described their methods and presented the results with a measure of error or variability. This survey has identified a number of issues that need to be addressed in order to improve experimental design and reporting in publications describing research using animals. Scientific publication is a powerful and important source of information; the authors of scientific publications therefore have a responsibility to describe their methods and results comprehensively, accurately and transparently, and peer reviewers and journal editors share the responsibility to ensure that published studies fulfil these criteria

    Relative survival: a useful tool to assess generalisability in longitudinal studies of health in older persons

    Get PDF
    Generalisability of longitudinal studies is threatened by issues such as choice of sampling frame, representativeness of the initial sample, and attrition. To determine representativeness, cohorts are often compared with the population of interest at baseline on demographic and health characteristics. This study illustrates the use of relative survival as a tool for assessing generalisability of results from a cohort of older people among whom death is a potential threat to generalisability.The authors used data from the 1921-26 cohort (n = 12,416, aged 70-75 in 1996) of the Australian Longitudinal Study on Women's Health (ALSWH). Vital status was determined by linkage to the National Death Index, and expected deaths were derived using Australian life tables. Relative survival was estimated using observed survival in the cohort divided by expected survival among women of the same age and State or Territory.Overall, the ALSWH women showed relative survival 9.5% above the general population. Within States and Territories, the relative survival advantage varied from 6% to 23%. The interval-specific relative survival remained relatively constant over the 12 years (1996-2008) under review, indicating that the survival advantage of the cohort has not diminished over time.This study demonstrates that relative survival can be a useful measure of generalisability in a longitudinal study of the health of the general population, particularly when participants are older

    The Family Name as Socio-Cultural Feature and Genetic Metaphor: From Concepts to Methods

    Get PDF
    A recent workshop entitled The Family Name as Socio-Cultural Feature and Genetic Metaphor: From Concepts to Methods was held in Paris in December 2010, sponsored by the French National Centre for Scientific Research (CNRS) and by the journal Human Biology. This workshop was intended to foster a debate on questions related to the family names and to compare different multidisciplinary approaches involving geneticists, historians, geographers, sociologists and social anthropologists. This collective paper presents a collection of selected communications
    corecore