122 research outputs found

    Ex Situ LIBS Analysis of WEST Divertor Wall Tiles after C3 Campaign

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    Fuel retention monitoring in tokamak walls requires the development of remote composition analysis methods such as laser-induced breakdown spectroscopy (LIBS). The present study investigates the feasibility of the LIBS method to analyse the composition and fuel retention in three samples from WEST divertor erosion marker tiles after the experimental campaign C3. The investigated samples originated from tile regions outside of strong erosion and deposition regions, where the variation of thin deposit layers is relatively small and facilitates cross-comparison between different analysis methods. The depth profiles of main constituents W, Mo and C were consistent with depth profiles determined by other composition analysis methods, such as glow-discharge optical emission spectroscopy (GDOES) and secondary ion mass spectrometry (SIMS). The average LIBS depth resolution determined from depth profiles was 100 nm/shot. The averaging of the spectra collected from multiple spots of a same sample allowed us to improve the signal-to-noise ratio, investigate the presence of fuel D and trace impurities such as O and B. In the investigated tile regions with negligible erosion and deposition, these impurities were clearly detectable during the first laser shot, while the signal decreased to noise level after a few subsequent laser shots at the same spot. LIBS investigation of samples originating from the deposition regions of tiles may further clarify LIBS’ ability to investigate trace impurities

    Examination of the risk of reinfection with hepatitis C among injecting drug users who have been tested in Glasgow

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    Unsafe injecting practices put injecting drug users (IDUs) at repeat exposure to infection with the hepatitis C virus (HCV). It has not yet been determined if spontaneously clearing one's primary infection influences the risk of reinfection; our aim was to estimate the relative risk of reinfection in IDUs who have cleared the virus. We conducted a retrospective study using a large database of HCV test results covering Greater Glasgow Health Board during 1993–2007 to calculate rates of infection and reinfection in current/former IDUs. The relative risk of (re)infection in previously infected compared with never-infected IDUs was estimated using Poisson regression, adjusting for age at study entry, sex, and calendar period of test. Although the rate of reinfection in IDUs who were HCV antibody-positive, RNA-negative at baseline was lower (7/100 person-years, 95% CI: 5–9) than the rate of acute infection in IDUs who were HCV antibody-negative at baseline (10/100 person-years, 95% CI: 9–12), the risk of reinfection was not significantly different than the risk of initial infection (adjusted rate ratio = 0.78, 95% CI: 0.57–1.08). We found only weak evidence for a reduced risk of HCV reinfection in IDUs who had cleared their previous infection. Further research among those who have cleared infection through antiviral therapy is needed to help inform decisions regarding treatment of IDUs

    Evolution of breeding plumages in birds: A multiple-step pathway to seasonal dichromatism in New World warblers (Aves: Parulidae)

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    Ecology and Evolution published by John Wiley & Sons Ltd Many species of birds show distinctive seasonal breeding and nonbreeding plumages. A number of hypotheses have been proposed for the evolution of this seasonal dichromatism, specifically related to the idea that birds may experience variable levels of sexual selection relative to natural selection throughout the year. However, these hypotheses have not addressed the selective forces that have shaped molt, the underlying mechanism of plumage change. Here, we examined relationships between life-history variation, the evolution of a seasonal molt, and seasonal plumage dichromatism in the New World warblers (Aves: Parulidae), a family with a remarkable diversity of plumage, molt, and life-history strategies. We used phylogenetic comparative methods and path analysis to understand how and why distinctive breeding and nonbreeding plumages evolve in this family. We found that color change alone poorly explains the evolution of patterns of biannual molt evolution in warblers. Instead, molt evolution is better explained by a combination of other life-history factors, especially migration distance and foraging stratum. We found that the evolution of biannual molt and seasonal dichromatism is decoupled, with a biannual molt appearing earlier on the tree, more dispersed across taxa and body regions, and correlating with separate life-history factors than seasonal dichromatism. This result helps explain the apparent paradox of birds that molt biannually but show breeding plumages that are identical to the nonbreeding plumage. We find support for a two-step process for the evolution of distinctive breeding and nonbreeding plumages: That prealternate molt evolves primarily under selection for feather renewal, with seasonal color change sometimes following later. These results reveal how life-history strategies and a birds\u27 environment act upon multiple and separate feather functions to drive the evolution of feather replacement patterns and bird coloration

    ERRATUM: "DETERMINING TITAN'S SPIN STATE FROM CASSINI RADAR IMAGES" (2008, AJ, 135, 1669)

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    We previously reported an initial determination of Titan's rotational state from fits to overlapping radar images. We have since discovered a coding error in software used to make these fits, which led to systematic offsets of 1-2 km in recovered positions. While our principal results remain qualitatively unchanged, with this error corrected, the pole movement we previously reported (our weakest result) is now counterindicated. Our revised best fit is essentially the same as the "best-fit no pole wobble" result discussed at the top of the second column on page 1675. The determined pole location did not change significantly after the bug fix and thus we still conclude that the spin axis is not in the plane formed by Titan's orbit normal and the normal to the Laplace plane. Due to the correlations between pole wobble and spin rate (see Figure 3 on page 1672), the new best fit has a spin rate that differs from the synchronous value by an amount that is three times smaller than the value reported in the paper. The pole location changed by less than 0.01 deg (~500 m on the surface) and rate of increase in spin decreased by a factor of 2 from the previous fit. The new best-fit parameter values with 1σ error bars are: pole right ascension 39.4934 ± 0.0249 deg, pole declination 83.4368 ± 0.0024 deg, spin rate 22.57731 ± 0.00011 deg/day (0.00033 deg/day greater than synchronous spin rate), derivative of pole right ascension –6.52 ± 4.20 deg/century, derivative of pole declination –0.2212 ± 0.3567 deg/century, and derivative of spin rate 0.0247 ± 0.0050 deg/day/century. The corrected version of Table 3 (below) shows the residual systematic and random error of the several candidate models discussed in the paper. Fixing the bug reduced the residual systematic error of all the fitted models. The four models in which spin rate is allowed to vary from synchronous either due to a change in spin rate (Column 5, numbered from the left) or a change in its time derivative (Column 6) or both (Columns 7 and 8) have lower residual systematic errors and thus better represent the data than do the purely synchronous fit (Column 3). For this reason, an asynchronous spin rate is still supported by the data, although efforts (e.g., Mitchell 2009) to quantitatively interpret the asynchroneity should take our revised determination into account. On the other hand, as depicted by Columns 7 and 8, allowing the pole movement terms to vary from the predicted (IAU Titan) values results in no significant improvement in the fit, thus large short-term pole movement is not supported by the data. In fact, the best-fit values and error bars for the pole movement are consistent with the long-term pole trends that were predicted prior to the Cassini mission

    Smoking cessation advice recorded during pregnancy in United Kingdom primary care

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    Background: United Kingdom (UK) national guidelines recommend that all pregnant women who smoke should be advised to quit at every available opportunity, and brief cessation advice is an efficient and cost-effective means to increase quit rates. The Quality and Outcomes Framework (QOF) implemented in 2004 requires general practitioners to document their delivery of smoking cessation advice in patient records. However, no specific targets have been set in QOF for the recording of this advice in pregnant women. We used a large electronic primary care database from the UK to quantify the pregnancies in which women who smoked were recorded to have been given smoking cessation advice, and the associated maternal characteristics. Methods: Using The Health Improvement Network database we calculated annual propotions of pregnant smokers between 2000 and 2009 with cessation advice documented in their medical records during pregnancy. Logistic regression was used to assess variation in the recording of cessation advice with maternal characteristics. Results: Among 45,296 pregnancies in women who smoked, recorded cessation advice increased from 7% in 2000 to 37% in 2004 when the QOF was introduced and reduced slightly to 30% in 2009. Pregnant smokers from the youngest age group (15–19) were 21% more likely to have a record of cessation advice compared to pregnant smokers aged 25–29 (OR 1.21, 95% CI 1.10-1.35) and pregnant smokers from the most deprived group were 38% more likely to have a record for cessation advice compared to pregnant smokers from the least deprived group (OR 1.38, 95% CI 1.14-1.68). Pregnant smokers with asthma were twice as likely to have documentation of cessation advice in their primary care records compared to pregnant smokers without asthma (OR 1.97, 95% CI 1.80-2.16). Presence of comorbidities such as diabetes, hypertension and mental illness also increased the likelihood of having smoking cessation advice recorded. No marked variations were observed in the recording of cessation advice with body mass index. Conclusion: Recorded delivery of smoking cessation advice for pregnant smokers in primary care has increased with some fluctuation over the years, especially after the implementation of the QOF, and varies with maternal characteristics

    UNderstanding uptake of Immunisations in TravellIng aNd Gypsy communities (UNITING): a qualitative interview study

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    Background: Gypsies, Travellers and Roma (referred to as Travellers) are less likely to access health services, including immunisation. To improve immunisation rates, we need to understand what helps and hinders individuals in these communities in taking up immunisations. Aims: (1) Investigate the barriers to and facilitators of acceptability and uptake of immunisations among six Traveller communities across four UK cities; and (2) identify possible interventions to increase uptake of immunisations in these Traveller communities that could be tested in a subsequent feasibility study. Methods: Three-phase qualitative study underpinned by the social ecological model. Phase 1: interviews with 174 Travellers from six communities: Romanian Roma (Bristol); English Gypsy/Irish Traveller (Bristol); English Gypsy (York); Romanian/Slovakian Roma (Glasgow); Scottish Showpeople (Glasgow); and Irish Traveller (London). Focus on childhood and adult vaccines. Phase 2: interviews with 39 service providers. Data were analysed using the framework approach. Interventions were identified using a modified intervention mapping approach. Phase 3: 51 Travellers and 25 service providers attended workshops and produced a prioritised list of potentially acceptable and feasible interventions. Results: There were many common accounts of barriers and facilitators across communities, particularly across the English-speaking communities. Scottish Showpeople were the most similar to the general population. Roma communities experienced additional barriers of language and being in a new country. Men, women and service providers described similar barriers and facilitators. There was widespread acceptance of childhood and adult immunisation, with current parents perceived as more positive than their elders. A minority of English-speaking Travellers worried about multiple/combined childhood vaccines, adult flu and whooping cough. Cultural concerns about vaccines offered during pregnancy and about human papillomavirus were most evident in the Bristol English Gypsy/Irish Traveller community. Language, literacy, discrimination, poor school attendance, poverty and housing were identified by Travellers and service providers as barriers for some. Trustful relationships with health professionals were important and continuity of care was valued. A few English-speaking Travellers described problems of booking and attending for immunisation. Service providers tailored their approach to Travellers, particularly the Roma. Funding cuts, NHS reforms and poor monitoring challenged their work. Five ‘top-priority’ interventions were agreed across communities and service providers to improve the immunisation among Travellers who are housed or settled on an authorised site: (1) cultural competence training for health professionals and frontline staff; (2) identification of Travellers in health records to tailor support and monitor uptake; (3) provision of a named frontline person in general practitioner practices to provide respectful and supportive service; (4) flexible and diverse systems for booking appointments, recall and reminders; and (5) protected funding for health visitors specialising in Traveller health, including immunisation. Limitations: No Travellers living on the roadside or on unofficial encampments were interviewed. We should exert caution in generalising to these groups. Future work: To include development, implementation and evaluation of a national policy plan (and practice guidance plan) to promote the uptake of immunisation among Traveller communities

    Youth social behaviour and network therapy (Y-SBNT) : adaptation of a family and social network intervention for young people who misuse alcohol and drugs – a randomised controlled feasibility trial

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    Background: Family interventions appear to be effective at treating young people’s substance misuse. However, implementation of family approaches in UK services is low. This study aimed to demonstrate the feasibility of recruiting young people to an intervention based on an adaptation of adult social behaviour and network therapy. It also sought to involve young people with experience of using substance misuse services in the research process. Objectives: To demonstrate the feasibility of recruiting young people to family and social network therapy and to explore ways in which young people with experience of using substance misuse services could be involved in a study of this nature. Design: A pragmatic, two-armed, randomised controlled open feasibility trial. Setting: Two UK-based treatment services for young people with substance use problems, with recruitment taking place from May to November 2014. Participants: Young people aged 12–18 years, newly referred and accepted for structured interventions for drug and/or alcohol problems. Interventions: A remote, web-based computer randomisation system allocated young people to adapted youth social behaviour and network therapy (Y-SBNT) or treatment as usual (TAU). Y-SBNT participants were intended to receive up to six 50-minute sessions over a maximum of 12 weeks. TAU participants continued to receive usual care delivered by their service. Main outcome measures: Feasibility was measured by recruitment rates, retention in treatment and follow-up completion rates. The main clinical outcome was the proportion of days on which the main problem substance was used in the preceding 90-day period as captured by the Timeline Follow-Back interview at 3 and 12 months. Results: In total, 53 young people were randomised (Y-SBNT, n = 26; TAU, n = 27) against a target of 60 (88.3%). Forty-two young people attended at least one treatment session [Y-SBNT 22/26 (84.6%); TAU 20/27 (74.1%)]; follow-up rates were 77.4% at month 3 and 73.6% at month 12. Data for nine young people were missing at both months 3 and 12, so the main clinical outcome analysis was based on 24 young people (92.3%) in the Y-SBNT group and 20 young people (74.1%) in the TAU group. At month 12, the average proportion of days that the main problem substance was used in the preceding 90 days was higher in the Y-SBNT group than in the TAU group (0.54 vs. 0.41; adjusted mean difference 0.13, 95% confidence interval –0.12 to 0.39; p = 0.30). No adverse events were reported. Seventeen young people with experience of substance misuse services were actively involved throughout the study. They informed key elements of the intervention and research process, ensuring that the intervention was acceptable and relevant to our target groups; contributing to the design of key trial documents, ideas for a new model of public involvement and this report. Two parents were also involved. Conclusions: The adapted intervention could be delivered in young people’s services, and qualitative interviews found that Y-SBNT was acceptable to young people, family members and staff. Engagement of family and network members proved difficult within the intervention and research aspects. The study proved the feasibility of this work in routine services but outcome measurement based on narrow substance use variables may be limited and may fail to capture other important changes in wider areas of functioning for young people. Validation of the EuroQol-5 Dimensions for young people aged 12–18 years should be considered and flexible models for involvement of young people in research are required to achieve inclusive representation throughout all aspects of the research process. Although recommendation of a full trial of the Y-SBNT intervention compared with TAU is not supported, this study can inform future intervention development and UK research within routine addiction services. Trial registration: Current Controlled Trials ISRCTN93446265. 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. 15. See the NIHR Journals Library website for further project information
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