3,306 research outputs found

    The large-scale axisymmetric magnetic topology of avery-low-mass fully-convective star

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    Understanding how cool stars produce magnetic fields within their interiors is crucial for predicting the impact of such fields, such as the activity cycle of the Sun. In this respect, studying fully convective stars enables us to investigate the role of convective zones in magnetic field generation. We produced a magnetic map of a rapidly rotating, very-low-mass, fully convective dwarf through tomographic imaging from time series of spectropolarimetric data. Our results, which demonstrate that fully convective stars are able to trigger axisymmetric large-scale poloidal fields without differential rotation, challenge existing theoretical models of field generation in cool stars.Comment: 17 pages, 4 figures, supplementary online material (including 2 figures

    A systematic review and meta-analysis of studies comparing burden from lung cancer and chronic obstructive pulmonary disease.

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    BACKGROUND:Chronic obstructive pulmonary disease and lung cancer are both life-limiting diseases that confer burden in the form of symptoms and affect functioning and quality of life. Comparing burden between these diseases is of interest to determine whether people with chronic obstructive pulmonary disease require improved access to Specialist Palliative Care. Access should be based on needs rather than diagnosis or prognosis but is limited for people with chronic obstructive pulmonary disease compared to lung cancer. AIM:The aim of this study was to synthesise research comparing burden from chronic obstructive pulmonary disease and lung cancer to estimate relative need for Specialist Palliative Care. DESIGN:A systematic review was conducted of observational quantitative studies published in English peer-reviewed journals comparing burden from chronic obstructive pulmonary disease and lung cancer (PROSPERO CRD42018108819). No limits were placed on disease stage. Meta-analyses were performed where studies used the same measure; otherwise, synthesis used a narrative approach. Risk of bias was assessed using the Agency for Healthcare Research and Quality tool. DATA SOURCES:Electronic databases were searched in September 2019. RESULTS:Of 790 articles returned, 13 were included, reporting 11 studies. Risk of bias was generally moderate. Except for pain, burden tended to be at least as substantial from chronic obstructive pulmonary disease as from lung cancer, with breathlessness and impacts on functioning being significantly worse. Longitudinal studies suggest that people with chronic obstructive pulmonary disease live with burden for longer. CONCLUSION:Efforts should be made to ensure that access to Specialist Palliative Care is commensurate with chronic obstructive pulmonary disease's substantial and long-lasting burden. Future research should clarify whether managing burden in chronic obstructive pulmonary disease and lung cancer requires different approaches

    Prayer and psychological health: a study among sixth-form pupils attending Catholic and Protestant schools in Northern Ireland

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    Eysenck's dimensional model of personality includes two indicators of psychological health, defined as neuroticism and psychoticism. In order to examine the association between psychological health and prayer, two samples of sixth-form pupils in Northern Ireland (16- to 18-year-olds) attending Catholic (N = 1246) and Protestant (N = 1060) schools completed the abbreviated Revised Eysenck Personality Questionnaire alongside a simple measure of prayer frequency. The data demonstrated a positive association between prayer frequency and better levels of psychological health as assessed by Eysenck's notion of psychoticism. Among pupils attending both Catholic and Protestant schools, higher levels of prayer were associated with lower psychoticism scores. Among pupils attending Catholic schools, however, higher levels of prayer were also associated with higher neuroticism scores

    Dialkyldithiophosphate Acids (HDDPs) as Effective Lubricants of Sol–Gel Titania Coatings in Technical Dry Friction Conditions

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    The goal of this study was the investigation of the effectiveness of dialkyldithiophosphate acids (HDDPs) films in improving the tribological properties of thin, sol– gel derived titania coatings. Amorphous, anatase, and rutile titania coatings were obtained using sol–gel dip–coating deposition after treatment at 100, 500, and 1,000 C, respectively. Titania coatings were then modified from the liquid phase by HDDPs acids having dodecyl-(C12), tetradecyl-(C14), and hexadecyl-(C16) alkyl chains deposited by dip–coating (DC) and Langmuir–Blodgett (LB) methods. The influence of the deposition procedure, the length of the HDDPs alkyl chain and the type of titania substrate on the surface morphology and tribological properties were studied. It was found, using wetting contact angle measurements, that these modifications of titania coatings decrease the surface free energy and increase its hydrophobicity. The surface topography imaged by Atomic force microscopy (AFM), exhibit island-like or agglomerate features for the DC deposition method, while smooth topographies were observed for LB depositions. Tribological tests were conducted by means of a microtribometer operating in the normal load range 30–100 mN. An enhancement of tribological properties was observed upon modification, as compared to unmodified titania

    Nanofiber fabrication in a temperature and humidity controlled environment for improved fibre consistency

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    To fabricate nanofibers with reproducible characteristics, an important demand for many applications, the effect of controlled atmospheric conditions on resulting electrospun cellulose acetate (CA) nanofibers was evaluated for temperature ranging 17.5 - 35°C and relative humidity ranging 20% - 70%. With the potential application of nanofibers in many industries, especially membrane and filter fabrication, their reproducible production must be established to ensure commercially viability.
Cellulose acetate (CA) solution (0.2 g/ml) in a solvent mixture of acetone/DMF/ethanol (2:2:1) was electrospun into nonwoven fibre mesh with the fibre diameter ranging from 150nm to 1µm.
The resulting nanofibers were observed and analyzed by scanning electron microscopy (SEM), showing a correlation of reducing average fibre diameter with increasing atmospheric temperature. A less pronounced correlation was seen with changes in relative humidity regarding fibre diameter, though it was shown that increased humidity reduced the effect of fibre beading yielding a more consistent, and therefore better quality of fibre fabrication.
Differential scanning calorimetry (DSC) studies observed lower melt enthalpies for finer CA nanofibers in the first heating cycle confirming the results gained from SEM analysis. From the conditions that were explored in this study the temperature and humidity that gave the most suitable fibre mats for a membrane purpose were 25.0°C and 50%RH due to the highest level of fibre diameter uniformity, the lowest level of beading while maintaining a low fibre diameter for increased surface area and increased pore size homogeneity. This study has highlighted the requirement to control the atmospheric conditions during the electrospinning process in order to fabricate reproducible fibre mats

    Effective silencing of ENaC by siRNA delivered with epithelial-targeted nanocomplexes in human cystic fibrosis cells and in mouse lung

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    Introduction Loss of the cystic fibrosis transmembrane conductance regulator in cystic fibrosis (CF) leads to hyperabsorption of sodium and fluid from the airway due to upregulation of the epithelial sodium channel (ENaC). Thickened mucus and depleted airway surface liquid (ASL) then lead to impaired mucociliary clearance. ENaC regulation is thus a promising target for CF therapy. Our aim was to develop siRNA nanocomplexes that mediate effective silencing of airway epithelial ENaC in vitro and in vivo with functional correction of epithelial ion and fluid transport. Methods We investigated translocation of nanocomplexes through mucus and their transfection efficiency in primary CF epithelial cells grown at air–liquid interface (ALI).Short interfering RNA (SiRNA)-mediated silencing was examined by quantitative RT-PCR and western analysis of ENaC. Transepithelial potential (Vt), short circuit current (Isc), ASL depth and ciliary beat frequency (CBF) were measured for functional analysis. Inflammation was analysed by histological analysis of normal mouse lung tissue sections. Results Nanocomplexes translocated more rapidly than siRNA alone through mucus. Transfections of primary CF epithelial cells with nanocomplexes targeting αENaC siRNA, reduced αENaC and βENaC mRNA by 30%. Transfections reduced Vt, the amiloride-sensitive Isc and mucus protein concentration while increasing ASL depth and CBF to normal levels. A single dose of siRNA in mouse lung silenced ENaC by approximately 30%, which persisted for at least 7 days. Three doses of siRNA increased silencing to approximately 50%. Conclusion Nanoparticle-mediated delivery of ENaCsiRNA to ALI cultures corrected aspects of the mucociliary defect in human CF cells and offers effective delivery and silencing in vivo

    Re-presenting the Paralympics: (contested) philosophies, production practices and the hypervisibility of disability

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    Studies that have engaged para-sport broadcasting, particularly through a narrative lens, have almost exclusively relied on textual and/or content analysis of the Paralympic Games as the source of cultural critique. We know far less about the decisions taken inside Paralympic broadcasters that have led to such representations. In this study – based on interviews with senior production and promotion staff at the UK’s Paralympic broadcaster, Channel 4 – we provide the first detailed examination of mediated para-sport from this vantage point. We explore the use of promotional devices such as athletes’ backstories – the “Hollywood treatment” – to both hook audiences and serve as a vehicle for achieving its social enterprise mandate to change public attitudes toward disability. In so doing, we reveal myriad tensions that coalesce around representing the Paralympics; with respect to the efforts made to balance the competing goals of key stakeholders and a stated desire to make the Paralympics both a commercial and socially progressive success

    Can programme theory be used as a 'translational tool’ to optimise health service delivery in a national early years’ initiative in Scotland: a case study

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    Background Theory-based evaluation (TBE) approaches are heralded as supporting formative evaluation by facilitating increased use of evaluative findings to guide programme improvement. It is essential that learning from programme implementation is better used to improve delivery and to inform other initiatives, if interventions are to be as effective as they have the potential to be. Nonetheless, few studies describe formative feedback methods, or report direct instrumental use of findings resulting from TBE. This paper uses the case of Scotland’s, National Health Service, early years’, oral health improvement initiative (Childsmile) to describe the use of TBE as a framework for providing feedback on delivery to programme staff and to assess its impact on programmatic action.<p></p> Methods In-depth, semi-structured interviews and focus groups with key stakeholders explored perceived deviations between the Childsmile programme 'as delivered’ and its Programme Theory (PT). The data was thematically analysed using constant comparative methods. Findings were shared with key programme stakeholders and discussions around likely impact and necessary actions were facilitated by the authors. Documentary review and ongoing observations of programme meetings were undertaken to assess the extent to which learning was acted upon.<p></p> Results On the whole, the activities documented in Childsmile’s PT were implemented as intended. This paper purposefully focuses on those activities where variation in delivery was evident. Differences resulted from the stage of roll-out reached and the flexibility given to individual NHS boards to tailor local implementation. Some adaptations were thought to have diverged from the central features of Childsmile’s PT, to the extent that there was a risk to achieving outcomes. The methods employed prompted national service improvement action, and proposals for local action by individual NHS boards to address this.<p></p> Conclusions The TBE approach provided a platform, to direct attention to areas of risk within a national health initiative, and to agree which intervention components were 'core’ to its hypothesised success. The study demonstrates that PT can be used as a 'translational tool’ to facilitate instrumental use of evaluative findings to optimise implementation within a complex health improvement programme.<p></p&gt

    Declining Burden of Malaria Over two Decades in a Rural Community of Muheza District, North-Eastern Tanzania.

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    The recently reported declining burden of malaria in some African countries has been attributed to scaling-up of different interventions although in some areas, these changes started before implementation of major interventions. This study assessed the long-term trends of malaria burden for 20 years (1992--2012) in Magoda and for 15 years in Mpapayu village of Muheza district, north-eastern Tanzania, in relation to different interventions as well as changing national malaria control policies.\ud Repeated cross-sectional surveys recruited individuals aged 0 -- 19 years from the two villages whereby blood smears were collected for detection of malaria parasites by microscopy. Prevalence of Plasmodium falciparum infections and other indices of malaria burden (prevalence of anaemia, splenomegaly and gametocytes) were compared across the years and between the study villages. Major interventions deployed including mobile clinic, bed nets and other research activities, and changes in national malaria control policies were also marked. In Magoda, the prevalence of P. falciparum infections initially decreased between 1992 and 1996 (from 83.5 to 62.0%), stabilized between 1996 and 1997, and further declined to 34.4% in 2004. A temporary increase between 2004 and 2008 was followed by a progressive decline to 7.2% in 2012, which is more than 10-fold decrease since 1992. In Mpapayu (from 1998), the highest prevalence was 81.5% in 1999 and it decreased to 25% in 2004. After a slight increase in 2008, a steady decline followed, reaching <5% from 2011 onwards. Bed net usage was high in both villages from 1999 to 2004 (>=88%) but it decreased between 2008 and 2012 (range, 28% - 68%). After adjusting for the effects of bed nets, age, fever and year of study, the risk of P. falciparum infections decreased significantly by >=97% in both villages between 1999 and 2012 (p < 0.001). The prevalence of splenomegaly (>40% to <1%) and gametocytes (23% to <1%) also decreased in both villages.Discussion and conclusionsA remarkable decline in the burden of malaria occurred between 1992 and 2012 and the initial decline (1992 -- 2004) was most likely due to deployment of interventions, such as bed nets, and better services through research activities. Apart from changes of drug policies, the steady decline observed from 2008 occurred when bed net coverage was low suggesting that other factors contributed to the most recent pattern. These results suggest that continued monitoring is required to determine causes of the changing malaria epidemiology and also to monitor the progress towards maintaining low malaria transmission and reaching related millennium development goals
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