621 research outputs found

    Small Engine Component Technology (SECT) study. Program report

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    The study was conducted to identify high payoff technologies for year 2000 small gas turbine applications and to provide a technology plan for guiding future research and technology efforts. A regenerative cycle turboprop engine was selected for a 19 passenger commuter aircraft application. A series of engines incorporating eight levels of advanced technologies were studied and their impact on aircraft performance was evaluated. The study indicated a potential reduction in fuel burn of 38.3 percent. At 1.00pergallonfuelprice,apotentialDOCbenefitof12.5percentwouldbeachieved.At1.00 per gallon fuel price, a potential DOC benefit of 12.5 percent would be achieved. At 2.00 per gallon, the potential DOC benefit would increase to 17.0 percent. Four advanced technologies are recommended and appropriate research and technology programs were established to reach the year 2000 goals

    Callose-associated silica deposition in Arabidopsis

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    The mechanism of biological silicification in plants remains to be elucidated. There are strong arguments supporting a role for the plant extracellular matrix and the β-1-3-glucan, callose, has been identified as a possible template for silica deposition in the common horsetail, Equisetum arvense. The model plant Arabidopsis thaliana, which is not known as a silica accumulator, can be engineered to produce mutants in which, following a pathogen-associated molecular pattern challenge, callose production in leaves is either induced (35S:PMR4-GFP) or not (pmr4). We have grown these mutants hydroponically in the presence of added silicon to test if the induction of callose results in greater silica deposition in the leaves. Callose induction was identified throughout leaf tissue of wild type Arabidopsis and the mutant 35S:PMR4-GFP but not in the mutant pmr4. Similarly both wild type Arabidopsis and the mutant 35S:PMR4-GFP showed extensive silicification of leaf tissue while the pmr4 mutant deposited very little silica in its leaf tissues. Wild type Arabidopsis and the mutant 35S:PMR4-GFP responded to a pathogen-like challenge by producing both callose and biogenic silica coincidently in their leaf tissues. Trichomes in particular showed both callose deposition and extensive silicification. The lack of both induced callose deposition and subsequent silicification in the pmr4 mutant strongly suggested that the biochemistry of callose formation and deposition were allied to biological silicification in Arabidopsis

    Beyond price: individuals' accounts of deciding to pay for private healthcare treatment in the UK

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    <p>Abstract</p> <p>Background</p> <p>Delivering appropriate and affordable healthcare is a concern across the globe. As countries grapple with the issue of delivering healthcare with finite resources and populations continue to age, more health-related care services or treatments may become an optional 'extra' to be purchased privately. It is timely to consider how, and to what extent, the individual can act as both a 'patient' and a 'consumer'. In the UK the majority of healthcare treatments are free at the point of delivery. However, increasingly some healthcare treatments are being made available via the private healthcare market. Drawing from insights from healthcare policy and social sciences, this paper uses the exemplar of private dental implant treatment provision in the UK to examine what factors people considered when deciding whether or not to pay for a costly healthcare treatment for a non-fatal condition.</p> <p>Methods</p> <p>Qualitative interviews with people (n = 27) who considered paying for dental implants treatments in the UK. Data collection and analysis processes followed the principles of the constant comparative methods, and thematic analysis was facilitated through the use of NVivo qualitative data software.</p> <p>Results</p> <p>Decisions to pay for private healthcare treatments are not simply determined by price. Decisions are mediated by: the perceived 'status' of the healthcare treatment as either functional or aesthetic; how the individual determines and values their 'need' for the treatment; and, the impact the expenditure may have on themselves and others. Choosing a private healthcare provider is sometimes determined simply by personal rapport or extant clinical relationship, or based on the recommendation of others.</p> <p>Conclusions</p> <p>As private healthcare markets expand to provide more 'non-essential' services, patients need to develop new skills and to be supported in their new role as consumers.</p

    Urinary arsenic profiles reveal exposures to inorganic arsenic from private drinking water supplies in Cornwall, UK

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    Private water supplies (PWS) in Cornwall, South West England exceeded the current WHO guidance value and UK prescribed concentration or value (PCV) for arsenic of 10 μg/L in 5% of properties surveyed (n = 497). In this follow-up study, the first of its kind in the UK, volunteers (n = 207) from 127 households who used their PWS for drinking, provided urine and drinking water samples for total As determination by inductively coupled plasma mass spectrometry (ICP-MS) and urinary As speciation by high performance liquid chromatography ICP-MS (HPLC-ICP-MS). Arsenic concentrations exceeding 10 μg/L were found in the PWS of 10% of the volunteers. Unadjusted total urinary As concentrations were poorly correlated (Spearman’s ρ = 0.36 (P < 0.001)) with PWS As largely due to the use of spot urine samples and the dominance of arsenobetaine (AB) from seafood sources. However, the osmolality adjusted sum, U-AsIMM, of urinary inorganic As species, arsenite (AsIII) and arsenate (AsV), and their metabolites, methylarsonate (MA) and dimethylarsinate (DMA), was found to strongly correlate (Spearman’s ρ: 0.62 (P < 0.001)) with PWS As, indicating private water supplies as the dominant source of inorganic As exposure in the study population of PWS users

    Stillbirth and loss: family practices and display

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    This paper explores how parents respond to their memories of their stillborn child over the years following their loss. When people die after living for several years or more, their family and friends have the residual traces of a life lived as a basis for an identity that may be remembered over a sustained period of time. For the parent of a stillborn child there is no such basis and the claim for a continuing social identity for their son or daughter is precarious. Drawing on interviews with the parents of 22 stillborn children, this paper explores the identity work performed by parents concerned to create a lasting and meaningful identity for their child and to include him or her in their families after death. The paper draws on Finch's (2007) concept of family display and Walter's (1999) thesis that links continue to exist between the living and the dead over a continued period. The paper argues that evidence from the experience of stillbirth suggests that there is scope for development for both theoretical frameworks

    Prolonged exposure to arsenic in UK private water supplies: toenail, hair and drinking water concentrations

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    Chronic exposure to arsenic (As) in drinking water is an established cause of cancer and other adverse health effects. Arsenic concentrations >10 μg L−1 were previously measured in 5% of private water supplies (PWS) in Cornwall, UK. The present study investigated prolongued exposure to As by measuring biomarkers in hair and toenail samples from 212 volunteers and repeated measurements of As in drinking water from 127 households served by PWS. Strong positive Pearson correlations (rp = 0.95) indicated stability of water As concentrations over the time period investigated (up to 31 months). Drinking water As concentrations were positively correlated with toenail (rp = 0.53) and hair (rp = 0.38) As concentrations – indicative of prolonged exposure. Analysis of washing procedure solutions provided strong evidence of the effective removal of exogenous As from toenail samples. Significantly higher As concentrations were measured in hair samples from males and smokers and As concentrations in toenails were negatively associated with age. A positive association between seafood consumption and toenail As and a negative association between home-grown vegetable consumption and hair As was observed for volunteers exposed to <1 As μg L−1 in drinking water. These findings have important implications regarding the interpretation of toenail and hair biomarkers. Substantial variation in biomarker As concentrations remained unaccounted for, with soil and dust exposure as possible explanations

    Paying for treatments? Influences on negotiating clinical need and decision-making for dental implant treatment

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    Background The aim of this study is to examine how clinicians and patients negotiate clinical need and treatment decisions within a context of finite resources. Dental implant treatment is an effective treatment for missing teeth, but is only available via the NHS in some specific clinical circumstances. The majority of people who receive this treatment therefore pay privately, often at substantial cost to themselves. People are used to paying towards dental treatment costs. However, dental implant treatment is much more expensive than existing treatments – such as removable dentures. We know very little about how dentists make decisions about whether to offer such treatments, or what patients consider when deciding whether or not to pay for them. Methods/Design Mixed methods will be employed to provide insight and understanding into how clinical need is determined, and what influences people's decision making processes when deciding whether or not to pursue a dental implant treatment. Phase 1 will use a structured scoping questionnaire with all the General dental practitioners (GDPs) in three Primary Care Trust areas (n = 300) to provide base-line data about existing practice in relation to dental implant treatment, and to provide data to develop a systematic sampling procedure for Phase 2. Phases 2 (GDPs) and 3 (patients) use qualitative focused one to one interviews with a sample of these practitioners (up to 30) and their patients (up to 60) to examine their views and experiences of decision making in relation to dental implant treatment. Purposive sampling for phases 2 and 3 will be carried out to ensure participants represent a range of socio-economic circumstances, and choices made. Discussion Most dental implant treatment is conducted in primary care. Very little information was available prior to this study about the quantity and type of treatment carried out privately. It became apparent during phase 2 that ISOD treatment was an unusual treatment in primary care. We thus extended our sample criteria for Phase 3 to include people who had had other implant supported restorations, although not single tooth replacements
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