Generation And Transmission Systems For Wave Power: A Feasibility Study

Following his recommendation to WESC, Dr. J.K. Wright was asked to approach GEC, Joseph Lucas and IRD with a view to seeking their support in assessing the technical feasibility and cost of converting wave energy, available in some mechanical form at the output of a device (WEC), to a more usable form for consumption on the UK mainland. At this time it was anticipated that this usable form would be electricity which would be fed into the CEGB/Scottish Boards grid network but it was also agreed that other energy forms were to be included. Early agreement by the companies on the desirability of such a study and discussions on how it might proceed led to the proposal 'Getting the Power to Shore' (1). The overall objectives of the study were agreed as (i) to identify and assess possible energy conversion and transmission system; (ii) estimate the performance and cost of the more promising systems and make a first order assessment of the impact of the operational and performance characteristics of particular designs on the overall economics of WEC systems; (iii) provide design information for the device teams developing particular WECs - both through independent studies and by way of consultancies; (iv) estimate the timescales and the R & D effort required to implement particular designs. The very large number of possible routes, the unfamiliar characteristics of the energy supply and the 'fluid' state of the thinking of the device teams were all factors which led TAG 6 to propose a preliminary, 9 month, 'broad brush' study as a necessary precursor to a detailed study of preferred systems. It is this preliminary study which is the subject of the present report. The succeeding sections of the report set out the specific objectives of the preliminary survey, set out the system options, discuss the assumptions which have been made in relation to wave and device properties and then discuss specific elements of the possible systems. The final sections relate these generic considerations to specific device designs and describe the preferred systems, ranked in order of technical 'credibility' and cost, which TAG 6 believe should be examined in greater detail during the second stage of its phase I study. Frequent reference is made to the working papers which have been prepared in the course of this study (a total of more than sixty are listed in Appendix III). It goes without saying that these papers are available for examination by anyone who wishes to obtain background information and supporting technical detail but the reader is asked to note that these are working papers and do not necessarily represent the present views of TAG 6. It would be surprising if detailed studies during stage II, when better information is available from device teams and the other TAGs, do not give rise to further shifts of emphasis

The use of interim data and Data Monitoring Committee recommendations in randomized controlled trial reports: frequency, implications and potential sources of bias

Background: Interim analysis of accumulating trial data is important to protect participant safety during randomized controlled trials (RCTs). Data Monitoring Committees (DMCs) often undertake such analyses, but their widening role may lead to extended use of interim analysis or recommendations that could potentially bias trial results.Methods: Systematic search of eight major publications: Annals of Internal Medicine, BMJ, Circulation, CID, JAMA, JCO, Lancet and NEJM, including all randomised controlled trials ( RCTs) between June 2000 and May 2005 to identify RCTs that reported use of interim analysis, with or without DMC involvement. Recommendations made by the DMC or based on interim analysis were identified and potential sources of bias assessed. Independent double data extraction was performed on all included trials.Results: We identified 1772 RCTs, of which 470 (27%; 470/1772) reported the use of a DMC and a further 116 (7%; 116/1772) trials reported some form of interim analysis without explicit mention of a DMC. There were 28 trials ( 24 with a formal DMC), randomizing a total of 79396 participants, identified as recommending changes to the trial that may have lead to biased results. In most of these, some form of sample size re-estimation was recommended with four trials also reporting changes to trial endpoints. The review relied on information reported in the primary publications and methods papers relating to the trials, higher rates of use may have occurred but not been reported.Conclusion: The reported use of interim analysis and DMCs in clinical trials has been increasing in recent years. It is reassuring that in most cases recommendations were made in the interest of participant safety. However, in practice, recommendations that may lead to potentially biased trial results are being made

Primary care capitation payments in the UK. An observational study

<p>Abstract</p> <p>Background</p> <p>In 2004 an allocation formula for primary care services was introduced in England and Wales so practices would receive equitable pay. Modifications were made to this formula to enable local health authorities to pay practices.</p> <p>Similar pay formulae were introduced in Scotland and Northern Ireland, but these are unique to the country and therefore could not be included in this study.</p> <p>Objective</p> <p>To examine the extent to which the Global Sum, and modifications to the original formula, determine practice funding.</p> <p>Methods</p> <p>The allocation formula determines basic practice income, the Global Sum. We compared practice Global Sum entitlements using the original and the modified allocation formula calculations.</p> <p>Practices receive an income supplement if Global Sum payments were below historic income in 2004. We examined current overall funding levels to estimate what the effect will be when the income supplements are removed.</p> <p>Results</p> <p>Virtually every Welsh and English practice (97%) received income supplements in 2004. Without the modifications to the formula only 72% of Welsh practices would have needed supplements. No appreciable change would have occurred in England.</p> <p>The formula modifications increased the Global Sum for 99.5% of English practices, while it reduced entitlement for every Welsh practice.</p> <p>In 2008 Welsh practices received approximately £6.15 (9%) less funding per patient per year than an identical English practice. This deficit will increase to 11.2% when the Minimum Practice Income Guarantee is abolished.</p> <p>Conclusions</p> <p>Identical practices in different UK countries do not receive equitable pay. The pay method disadvantages Wales where the population is older and has higher health needs.</p

Improving identification of familial hypercholesterolaemia in primary care: Derivation and validation of the familial hypercholesterolaemia case ascertainment tool (FAMCAT)

Objective: Heterozygous familial hypercholesterolaemia (FH) is a common autosomal dominant disorder. The vast majority of affected individuals remain undiagnosed, resulting in lost opportunities for preventing premature heart disease. Better use of routine primary care data offers an opportunity to enhance detection. We sought to develop a new predictive algorithm for improving identification of individuals in primary care who could be prioritised for further clinical assessment using established diagnostic criteria. Methods: Data were analysed for 2,975,281 patients with total or LDL-cholesterol measurement from 1 Jan 1999 to 31 August 2013 using the Clinical Practice Research Datalink (CPRD). Included in this cohort study were 5050 documented cases of FH. Stepwise logistic regression was used to derive optimal multivariate prediction models. Model performance was assessed by its discriminatory accuracy (area under receiver operating curve [AUC]). Results: The FH prediction model (FAMCAT), consisting of nine diagnostic variables, showed high discrimination (AUC 0.860, 95% CI 0.848–0.871) for distinguishing cases from non-cases. Sensitivity analysis demonstrated no significant drop in discrimination (AUC 0.858, 95% CI 0.845–0.869) after excluding secondary causes of hypercholesterolaemia. Removing family history variables reduced discrimination (AUC 0.820, 95% CI 0.807–0.834), while incorporating more comprehensive family history recording of myocardial infraction significantly improved discrimination (AUC 0.894, 95% CI 0.884–0.904). Conclusion: This approach offers the opportunity to enhance detection of FH in primary care by identifying individuals with greatest probability of having the condition. Such cases can be prioritised for further clinical assessment, appropriate referral and treatment to prevent premature heart disease

Facet-joint injections for non-specific low back pain: a feasibility RCT

Background: Pain of lumbar facet-joint origin is a common cause of low back pain in adults and may lead to chronic pain and disability, with associated health and socioeconomic implications. The socioeconomic burden includes an inability to return to work resulting in loss of productivity in addition to direct and indirect health-care utilisation costs. Lumbar facet-joints are paired synovial joints between the superior and inferior articular processes of consecutive lumbar vertebrae and between the fifth lumbar vertebra and the sacrum. Facet-joint pain is defined as pain that arises from any structure that is part of the facet-joints, including the fibrous capsule, synovial membrane, hyaline cartilage and bone. This pain may be treated by intra-articular injections with local anaesthetic and steroid, although this treatment is not standardised. At present, there is no definitive research to support the use of targeted lumbar facet-joint injections to manage this pain. Because of the lack of high-quality, robust clinical evidence, the National Institute for Health and Care Excellence (NICE) guidelines on the management of chronic low back pain [NICE. Low Back Pain in Adults: Early Management. Clinical guideline (CG88). London: NICE; 2009] did not recommend the use of spinal injections despite their perceived potential to reduce pain intensity and improve rehabilitation, with NICE calling for further research to be undertaken. The updated guidelines [NICE. Low Back Pain and Sciatica in Over 16s: Assessment and Management. NICE guideline (NG59). London: NICE; 2016] again do not recommend the use of spinal injections. Objectives: To assess the feasibility of carrying out a definitive study to evaluate the clinical effectiveness and cost-effectiveness of lumbar facet-joint injections compared with a sham procedure in patients with non-specific low back pain of > 3 months’ duration. Design: Blinded parallel two-arm pilot randomised controlled trial. Setting: Initially planned as a multicentre study involving three NHS trusts in the UK, recruitment took place in the pain and spinal orthopaedic clinics at Barts Health NHS Trust only. Participants: Adult patients referred by their GP to the specialist clinics with non-specific low back pain of at least 3 months’ duration despite NICE-recommended best non-invasive care (education and one of a physical exercise programme, acupuncture or manual therapy). Patients who had already received lumbar facet-joint injections or who had had previous back surgery were excluded. Interventions: Participants who had a positive result following a diagnostic test (single medial branch nerve blocks) were randomised and blinded to receive either intra-articular lumbar facet-joint injections with steroids (intervention group) or a sham procedure (control group). All participants were invited to attend a group-based combined physical and psychological (CPP) programme. Main outcome measures: In addition to the primary outcome of feasibility, questionnaires were used to assess a range of pain-related (including the Brief Pain Inventory and Short-Form McGill Pain Questionnaire version 2) and disability-related (including the EuroQol-5 Dimensions five-level version and Oswestry Low Back Pain Questionnaire) issues. Health-care utilisation and cost data were also assessed. The questionnaire visits took place at baseline and at 6 weeks, 3 months and 6 months post randomisation. The outcome assessors were blinded to the allocation groups. Results: Of 628 participants screened for eligibility, nine were randomised to receive the study intervention (intervention group, n = 5; sham group, n = 4), six completed the CPP programme and eight completed the study. Limitations: Failure to achieve our expected recruitment targets led to early closure of the study by the funder. Conclusions: Because of the small number of participants recruited to the study, we were unable to draw any conclusions about the clinical effectiveness or cost-effectiveness of intra-articular lumbar facet-joint injections in the management of non-specific low back pain. Although we did not achieve the target recruitment rate from the pain clinics, we demonstrated our ability to develop a robust study protocol and deliver the intended interventions safely to all nine randomised participants, thus addressing many of the feasibility objectives. Future work: Stronger collaborations with primary care may improve the recruitment of patients earlier in their pain trajectory who are suitable for inclusion in a future trial. Trial registration: EudraCT 2014-003187-20 and Current Controlled Trials ISRCTN12191542. Funding: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 74. See the NIHR Journals Library website for further project information

Processes controlling dissolved oxygen and pH in the upper Willamette River basin, Oregon, 1994 /

Shipping list no.: 96-0026-P.Includes bibliographical references (p. 34-35).Mode of access: Internet

Occurrence of selected trace elements and organic compounds and their relation to land use in the Willamette River basin, Oregon, 1992-94 /

Shipping list no.: 97-0077-P.Includes bibliographical references (p. 53-55).Mode of access: Internet