289 research outputs found

    Does fine sediment source as well as quantity affect salmonid embryo mortality and development?

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    Fine sediments are known to be an important cause of increased mortality in benthic spawning fish. To date, most of the research has focussed on the relationship between embryo mortality and the quantity of fine sediment accumulated in the egg pocket. However, recent evidence suggests a) that the source of fine sediment might also be important, and b) that fitness of surviving embryos post-hatch might also be impacted by the accumulation of fine sediments. In this paper, we report an experiment designed to simulate the incubation environment of brown trout (Salmo trutta) and Atlantic salmon (Salmo salar). During the experiment, the incubating embryos were exposed to different quantities of fine (< 63 ?m) sediment derived from four different sources; agricultural topsoils, damaged road verges, eroding river channel banks and tertiary level treated sewage. Results showed that mass and source are independently important for determining the mortality and fitness of alevin. Differences between species were observed, such that brown trout are less sensitive to mass and source of accumulated sediment. We demonstrate for the first time that sediment source is an additional control on the impact of fine sediment, and that this is primarily controlled by the organic matter content and oxygen consumption of the catchment source material

    Randomised controlled trial of school-based humanistic counselling for emotional distress in young people: Feasibility study and preliminary indications of efficacy

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    The purpose of this study was to test the feasibility of a randomised controlled trial comparing six weeks of humanistic school-based counselling versus waiting list in the reduction of emotional distress in young people, and to obtain initial indications of efficacy. Following a screening procedure, young people (13 - 15 years old) who experienced emotional distress were randomised to either humanistic counselling or waiting list in this multi-site study. Outcomes were assessed using a range of self-report mental health measures, with the emotional symptoms subscale of the Strengths and Difficulties Questionnaire (SDQ) acting as the primary outcome indicator. Recruitment procedures were successful, with 32 young people consenting to participate in the trial and 27 completing endpoint measures. Trial procedures were acceptable to all involved in the research. No significant differences were found between the counselling and waiting list groups in reductions in levels of emotional symptoms (Hedges' g = 0.03), but clients allocated to counselling showed significantly greater improvement in prosocial behaviour (g = 0.89) with an average effect size (g) across the nine outcome measures of 0.25. Participants with higher levels of depressive symptoms showed significantly greater change. This study suggested that a randomised controlled trial of counselling in schools is acceptable and feasible, although initial indications of efficacy are mixed

    Electrochemical Detection of Free Chlorine at Inkjet Printed Silver Electrodes

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    A low-cost, reliable and sensitive electrochemical method for free chlorine analysis in water using inkjet printed silver electrodes is presented. Free chlorine detection was based on linear sweep voltammetry (LSV) analysis of AgCl/Ag2O films formed over an inkjet printed silver electrode by the spontaneous reaction between silver and free chlorine species (i.e. HClO and ClO−) present in solution. The formation of AgCl/Ag2O films was studied and characterized by high resolution scanning electron microscopy (HR SEM) and X-ray photoelectron spectroscopy (XPS) techniques. LSV characterization demonstrated a quantitative linear relationship between the amount of AgCl/Ag2O formed and the concentration of free chlorine in water within a range from 1 to 100 ppm. After optimization of several parameters (e.g. scan rate, reaction time, starting potential), lowest detectable free chlorine concentration was 0.4 ppm (by standard addition method), while the limit of detection (S/N = 3) was equal to 2 ppm, with a sensitivity of 30 μC/ppm. The validation of the proposed methodology was performed by comparison with the standard N,N-diethylparaphenylenediamine (DPD) method for analyzing swimming pool water samples. Finally, it was demonstrated that reproducible and disposable silver electrodes could be easily prepared by inkjet printing in a large scale and in any required geometry to fit on-line and on-site free chlorine analyses requirements

    The Treatment In Morning versus Evening (TIME) study:Analysis of recruitment, follow-up and retention rates post-recruitment

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    Abstract Background The use of information technology (IT) is now the preferred method of capturing and storing clinical research data. The Treatment In Morning versus Evening (TIME) study predominantly uses electronic data capture and IT to compare morning dosing of hypertensive medication against evening dosing. Registration, consent, participant demographics and follow-up data are all captured via the study website. The aim of this article is to assess the success of the TIME methodology compared with similar studies. Methods To assess the TIME study, published literature on similar clinical trials was reviewed and compared against TIME recruitment, follow-up and email interaction data. Results The TIME website registered 31,695 individuals, 21,116 of whom were randomised. Recruitment cost per randomised participant varied by strategy: £17.40 by GP practice, £3.08 by UK Biobank and £58.82 for GoShare. Twelve-month follow-up retention rates were 96%. A total of 1089 participants have withdrawn from their assigned time of dosing, 2% of whom have declined follow-up by record linkage or further contact. When the TIME data are compared with similar study data, study recruitment is very successful. However, TIME suffers difficulties with participant follow-up and withdrawal rates similar to those of conventional studies. Conclusions The TIME study has been successful in recruitment. Follow-up, retention rates and withdrawal rates are all acceptable, but ongoing work is required to ensure participants remain engaged with the study. Various recruitment strategies are necessary, and all viable options should be encouraged to maintain participant engagement throughout the life of studies using IT

    Identifying networks in social media: The case of #Grexit

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    We examine the intensity of ‘#Grexit’ usage in Twitter during a period of economic and financial turbulence. Using a frequency-analysis technique, we illustrate that we can extract detailed information from social media data. This allows us to map the networks of interest as it is reflected in Twitter. Our findings identify high-interest in Grexit from Twitter users in key peripheral countries, core Eurozone members as well as core EU member states outside the Eurozone. Overall, our study presents a useful tool for identifying clusters. This is part of a new research agenda utilising the information extracted from big data available via social media channels

    Educational intervention improves anticoagulation control in atrial fibrillation patients:the TREAT randomised trial

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    Background: Stroke prevention in atrial fibrillation (AF), most commonly with warfarin, requires maintenance of a narrow therapeutic target (INR 2.0 to 3.0) and is often poorly controlled in practice. Poor patient-understanding surrounding AF and its’ treatment may contribute to patient’s willingness to adhere to recommendations. Method: A theory-driven intervention, developed using patient interviews and focus groups, consisting of a one-off group session (1-6 patients) utilising an ‘expert-patient’ focussed DVD, educational booklet, self-monitoring diary and worksheet, was compared in a randomised controlled trial (ISRCTN93952605) against usual care, with patient postal follow-ups at 1, 2, 6, and 12-months. Ninety-seven warfarin-naïve AF patients were randomised to intervention (n=46, mean age (SD) 72.0 (8.2), 67.4% men), or usual care (n=51, mean age (SD) 73.7 (8.1), 62.7% men), stratified by age, sex, and recruitment centre. Primary endpoint was time within therapeutic range (TTR); secondary endpoints included knowledge, quality of life, anxiety/depression, beliefs about medication, and illness perceptions. Main findings: Intervention patients had significantly higher TTR than usual care at 6-months (76.2% vs. 71.3%; p=0.035); at 12-months these differences were not significant (76.0% vs. 70.0%; p=0.44). Knowledge increased significantly across time (F (3, 47) = 6.4; p<0.01), but there were no differences between groups (F (1, 47) = 3.3; p = 0.07). At 6-months, knowledge scores predicted TTR (r=0.245; p=0.04). Patients’ scores on subscales representing their perception of the general harm and overuse of medication, as well as the perceived necessity of their AF specific medications predicted TTR at 6- and 12-months. Conclusions: A theory-driven educational intervention significantly improves TTR in AF patients initiating warfarin during the first 6-months. Adverse clinical outcomes may potentially be reduced by improving patients’ understanding of the necessity of warfarin and reducing their perception of treatment harm. Improving education provision for AF patients is essential to ensure efficacious and safe treatment

    Contact metamorphism associated to the Penamacor - Monsanto granitic intrusion (Central Portugal): geochemical, isotopic and mineralogical features

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    Contact metamorphism related to Variscan and late-Variscan granitic plutons in the Iberian Peninsula is superimposed on medium-grade regional metamorphism, making it often difficult to evaluate per se the thermal effects due to those intrusions and explaining the paucity of scientific literature on the subject. An exhaustive set of geochemical, isotopic and mineralogical data on the contact-zone metasediments hosting the Penamacor-Monsanto granite (Central Iberian Zone, Portugal) provides a significant contribution to the characterization of low- to intermediate-grade contact metamorphism in geological contexts formerly affected by regional metamorphism. The metasediments hosting the Penamacor-Monsanto pluton belong to the extensive detrital sequence of the ante-Ordovician Schist-Greywacke Complex. Bulk geochemistry, oxygen isotope data and crystal-chemistry of key minerals from those contact-zone and neighbouring metasediments have made it possible to infer metamorphic conditions on the contact zone of this granitic intrusion, and to distinguish them from late boron-metasomatism at the exocontact. Mineral paragenesis (muscovite + biotite + chlorite quartz plagioclase cordierite, in spotted-schists; biotite + chlorite quartz plagioclase ( cordierite), in hornfelses) and the composition of these coexisting mineral phases indicate that most of the contact rocks reached the biotite zone (or even the cordierite zone, in some cases), equivalent to upper greenschist – lower amphibolite metamorphic grade. The relatively narrow range of O-isotope temperatures estimated for the crystallization of the marginal granites (550-625ºC) explains the absence of significant effects of thermal flow anisotropy on the contact-zone rocks. Besides, textural, paragenetic, mineralogical, isotopic and geochemical nuances observed in hornfelses and spotted-schists seem mainly related to the local host-rock heterogeneities, rather than to thermal effects. The relatively low temperatures estimated for granitoid emplacement and their restricted isotopic and mineralogical impacts on the metasedimentary host-rocks account for the narrow metamorphic aureole associated with the Penamacor-Monsanto pluton, and suggest this massif may correspond to the outcropping tip of a larger granitic intrusion at depth.Las intrusions graníticas Varíscicas y tardivaríscicas de la Península Ibérica dieron lugar a un metamorfsmo de contacto que afecta a un encajante previamente sometido a un metamorfsmo regional de grado medio, lo que difculta separar los efectos térmicos de aquellos regionales, y explica la escasez de estudios sobre el mismo. El estudio detallado de la zona de contacto entre el Granito de Penamacor-Monsanto (Zona Centro-Ibérica; Portugal) y su encajante metasedimentario mediante técnicas geoquímicas, mineralógicas e isotópicas supone una notable contribución al conocimiento y caracterización del metamorfsmo de contacto de grados bajos a intermedios en contextos geológicos previamente afectados por metamorfsmo regional. El encajante metasedimentario del Plutón de Penamacor-Monsanto es parte de la amplia secuencia detrítica ante-Ordovícia conocida como Complejo Esquisto-Grawackico. Datos geoquímicos de roca total y cristaloquímicos de los minerales más característicos, y relaciones isotópicas de oxígeno en la zona de contacto y metasedimentos aledaños permiten inferir las condiciones metamórfcas en la zona de contacto de dicha intrusión, y diferenciarla de aquella afectada por metasomatismo tardío por B. La paragénesis mineral (muscovita + biotita + clorita ± cuarzo ± plagioclasa ± cordierita en los esquistos moteados; biotita + clorita ± cuarzo ± plagiclasa (± cordierita) en corneanas) y la composición de las fases minerales coexistentes indican que la mayoría de rocas del contacto alcanzaron la zona de la biotita (e incluso, en algunos casos, aquella de la cordierita), equivalente a la parte alta del grado metamórfco de los esquistos verdes, o a la parte baja de las anfbolitas. El rango relativamente pequeño de temperaturas de cristalización de los granitos marginales (550-625°C), calculado mediante isótopos de oxígeno, explica la carencia de anisotropías térmicas signifcativas en las rocas del contacto. Las sutiles diferencias texturales, paragenéticas, mineralógicas, isotópicas y geoquímicas en esquistos moteados y corneanas parecen relacionadas con heterogeneidades locales de los encajantes, y no con efectos térmicos diferenciados. Las temperaturas relativamente bajas estimadas durante la intrusión del granito de Penamacor-Monsanto, y el limitado efecto mineralógico e isotópico sobre el encajante metasedimentario, dan lugar a una aureola de contacto estrecha, y sugieren que este macizo puede corresponder al techo de una intrusión mayor en profundidad.Funding was provided by FCT—Fundação para a Ciên cia e Tecnologia, through project METMOB (PTDC/CTE-GIX/116204/2009
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