523 research outputs found

    OH maser mapping of the evolved star HD 179821: evidence for interacting outllows

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    The evolved star HD 179821 continues to be the subject of much debate as to whether it is a nearby post-asymptotic giant branch (post-AGB) star or a distant high initial mass post-red supergiant. We have mapped the OH maser emission around HD 179821 in the 1612- and 1667-MHz lines with the MERLIN interferometer array at a resolution of 0.4 arcsec and 0.35 km s−1. The OH emission lies in a thick shell with inner and outer radii of 1.3 and and expansion velocity of 30 km s−1. Although we find some evidence for acceleration and for deviations from spherical symmetry, the bulk of the maser emission is consistent with a constant-velocity spherical shell. The extent of the shell agrees with H2O and OH dissociation models and supports a distance estimate of 6 kpc. However, the shell is incomplete and appears to have been disrupted by more recent collimated outflow activity within the last 1500 yr. We suggest that this activity is also responsible for the active envelope chemistry (in particular the presence of HCO+) and for the apparent offset of the star from the centre of the shell. The luminous yellow hypergiant star IRC +10420 also shows signs of recent outflows, and HD 179821 may be at a similar, perhaps slightly earlier, phase of evolution. We suggest that the SiO thermal emission arises from the same detached envelope as the OH maser emission as in IRC +10420. If so then this would strengthen the connection between these two stars and probably rule out a post-AGB status for HD 179821

    Dynamic Set Intersection

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    Consider the problem of maintaining a family FF of dynamic sets subject to insertions, deletions, and set-intersection reporting queries: given S,SFS,S'\in F, report every member of SSS\cap S' in any order. We show that in the word RAM model, where ww is the word size, given a cap dd on the maximum size of any set, we can support set intersection queries in O(dw/log2w)O(\frac{d}{w/\log^2 w}) expected time, and updates in O(logw)O(\log w) expected time. Using this algorithm we can list all tt triangles of a graph G=(V,E)G=(V,E) in O(m+mαw/log2w+t)O(m+\frac{m\alpha}{w/\log^2 w} +t) expected time, where m=Em=|E| and α\alpha is the arboricity of GG. This improves a 30-year old triangle enumeration algorithm of Chiba and Nishizeki running in O(mα)O(m \alpha) time. We provide an incremental data structure on FF that supports intersection {\em witness} queries, where we only need to find {\em one} eSSe\in S\cap S'. Both queries and insertions take O\paren{\sqrt \frac{N}{w/\log^2 w}} expected time, where N=SFSN=\sum_{S\in F} |S|. Finally, we provide time/space tradeoffs for the fully dynamic set intersection reporting problem. Using MM words of space, each update costs O(MlogN)O(\sqrt {M \log N}) expected time, each reporting query costs O(NlogNMop+1)O(\frac{N\sqrt{\log N}}{\sqrt M}\sqrt{op+1}) expected time where opop is the size of the output, and each witness query costs O(NlogNM+logN)O(\frac{N\sqrt{\log N}}{\sqrt M} + \log N) expected time.Comment: Accepted to WADS 201

    Turning to art as a positive way of living with cancer: A qualitative study of personal motives and contextual influences

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    Why do some women turn to creative art-making after a diagnosis of cancer? Eleven women provided qualitative accounts that were analyzed following guidelines for interpretative phenomenological analysis (IPA). Some described taking up artistic leisure activities initially in order to manage emotional distress. Others emphasized their need for positive well-being, taking up art to experience achievement and satisfaction, to regain a positive identity, and to normalize family dynamics in the context of living with cancer. Participants’ turn to art-making was facilitated by biographical and contextual factors, including pre-existing craft skills, long-standing personal values and coping philosophies, family role models for managing adversity, and the supportive encouragement of family and friends. Other research has acknowledged that positive lifestyle change and post-traumatic growth can occur after a cancer diagnosis, and this study reveals a multi-faceted process. The findings suggest a need for further research into the experiences that facilitate positive lifestyle change and subjective well-being among people who are living with cancer

    Flame assisted chemical vapour deposition of NiO hole transport layers for planar perovskite cells

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    Thin films of polycrystalline NiO were deposited by Flame Assisted Chemical Vapour Deposition, which is an ideal process for in-line, atmospheric pressure deposition of wide area coatings. This, along with the ability to use aqueous salts rather than organic precursors or solvents makes it well suited for industrial integration. To establish the capability of FACVD deposited NiO for use as a low cost, commercially viable option planar perovskite cells were fabricated under ambient conditions. The resulting cells showed the importance of both the flame composition and NiO thickness. A continuous NiO Hole Transport Layer (HTL) was achieved for ca. 36 nm thick film, which showed a maximum higher efficiency of 12.3% over that of the control (11.8%) which used a spin coated HTL. This was mainly driven by the large improvement in the current density from 16.6 mA/cm2 to 19.0 mA/cm2

    Flame assisted chemical vapour deposition NiO hole transport layers for mesoporous carbon perovskite cells

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    Flame assisted chemical vapour deposition was utilised to directly deposit polycrystalline mesoporous NiO to enhance charge transport within carbon perovskite solar cells (C-PSC). This versatile technique is highly suited for deposition of large area thin films along with the ability to use simple, stable aqueous salts. The combination of low cost methods of screen printing and FACVD to produce the C-PSC make this an attractive route towards commercialisation. The effects of deposition parameters on the morphology, crystallinity and density of the deposited NiO are discussed, along with the importance of use of a low propane, ‘lean flame’ on both the NiO and underlying F-doped tin oxide electrode. The thickness of the NiO layer was found to be critical in optimising the C-PSC efficiency. Addition of the NiO layer resulted in an increased short circuit current density (17.30 mA cm−2 to 20.28 mA cm−2). At an estimated NiO thickness of 17 nm the average cell efficiency (10.73%) surpassed that of the control sample (9.08%) so confirming the promise of this technique

    Clinician-rated mental health in outpatient child and adolescent mental health services: associations with parent, teacher and adolescent ratings

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    <p>Abstract</p> <p>Background</p> <p>Clinician-rated measures are used extensively in child and adolescent mental health services (CAMHS). The Health of the Nation Outcome Scales for Children and Adolescents (HoNOSCA) is a short clinician-rated measure developed for ordinary clinical practice, with increasing use internationally. Several studies have investigated its psychometric properties, but there are few data on its correspondence with other methods, rated by other informants. We compared the HoNOSCA with the well-established Achenbach System of Empirically Based Assessment (ASEBA) questionnaires: the Child Behavior Checklist (CBCL), the Teacher's Report Form (TRF), and the Youth Self-Report (YSR).</p> <p>Methods</p> <p>Data on 153 patients aged 6-17 years at seven outpatient CAMHS clinics in Norway were analysed. Clinicians completed the HoNOSCA, whereas parents, teachers, and adolescents filled in the ASEBA forms. HoNOSCA <it>total score </it>and nine of its scales were compared with similar ASEBA scales. With a multiple regression model, we investigated how the ASEBA ratings predicted the clinician-rated HoNOSCA and whether the different informants' scores made any unique contribution to the prediction of the HoNOSCA scales.</p> <p>Results</p> <p>We found moderate correlations between the total problems rated by the clinicians (HoNOSCA) and by the other informants (ASEBA) and good correspondence between eight of the nine HoNOSCA scales and the similar ASEBA scales. The exception was HoNOSCA scale 8 <it>psychosomatic symptoms </it>compared with the ASEBA s<it>omatic problems </it>scale. In the regression analyses, the CBCL and TRF <it>total problems </it>scores together explained 27% of the variance in the HoNOSCA <it>total scores </it>(23% for the age group 11-17 years, also including the YSR). The CBCL provided unique information for the prediction of the HoNOSCA <it>total score</it>, HoNOSCA scale 1 <it>aggressive behaviour</it>, HoNOSCA scale 2 <it>overactivity or attention problems</it>, HoNOSCA scale 9 <it>emotional symptoms</it>, and HoNOSCA scale 10 <it>peer problems; </it>the TRF for all these except HoNOSCA scale 9 <it>emotional symptoms; </it>and the YSR for HoNOSCA scale 9 <it>emotional symptoms </it>only.</p> <p>Conclusion</p> <p>This study supports the concurrent validity of the HoNOSCA. It also demonstrates that parents, teachers and adolescents all contribute unique information in relation to the clinician-rated HoNOSCA, indicating that the HoNOSCA ratings reflect unique perspectives from multiple informants.</p

    PatternLab for proteomics: a tool for differential shotgun proteomics

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    <p>Abstract</p> <p>Background</p> <p>A goal of proteomics is to distinguish between states of a biological system by identifying protein expression differences. Liu <it>et al</it>. demonstrated a method to perform semi-relative protein quantitation in shotgun proteomics data by correlating the number of tandem mass spectra obtained for each protein, or "spectral count", with its abundance in a mixture; however, two issues have remained open: how to normalize spectral counting data and how to efficiently pinpoint differences between profiles. Moreover, Chen <it>et al</it>. recently showed how to increase the number of identified proteins in shotgun proteomics by analyzing samples with different MS-compatible detergents while performing proteolytic digestion. The latter introduced new challenges as seen from the data analysis perspective, since replicate readings are not acquired.</p> <p>Results</p> <p>To address the open issues above, we present a program termed PatternLab for proteomics. This program implements existing strategies and adds two new methods to pinpoint differences in protein profiles. The first method, ACFold, addresses experiments with less than three replicates from each state or having assays acquired by different protocols as described by Chen <it>et al</it>. ACFold uses a combined criterion based on expression fold changes, the AC test, and the false-discovery rate, and can supply a "bird's-eye view" of differentially expressed proteins. The other method addresses experimental designs having multiple readings from each state and is referred to as nSVM (natural support vector machine) because of its roots in evolutionary computing and in statistical learning theory. Our observations suggest that nSVM's niche comprises projects that select a minimum set of proteins for classification purposes; for example, the development of an early detection kit for a given pathology. We demonstrate the effectiveness of each method on experimental data and confront them with existing strategies.</p> <p>Conclusion</p> <p>PatternLab offers an easy and unified access to a variety of feature selection and normalization strategies, each having its own niche. Additionally, graphing tools are available to aid in the analysis of high throughput experimental data. PatternLab is available at <url>http://pcarvalho.com/patternlab</url>.</p

    National profile of foot orthotic provision in the United Kingdom, part 2 : podiatrist, orthotist and physiotherapy practices.

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    Background A national survey recently provided the first description of foot orthotic provision in the United Kingdom. This article aims to profile and compare the foot orthoses practice of podiatrists, orthotists and physiotherapists within the current provision. Method Quantitative data were collected from podiatrists, orthotists and physiotherapists via an online questionnaire. The topics, questions and answers were developed through a series of pilot phases. The professions were targeted through electronic and printed materials advertising the survey. Data were captured over a 10 month period in 2016. Differences between professions were investigated using Chi squared and Fischer’s exact tests, and regression analysis was used to predict the likelihood of each aspect of practice in each of the three professions. Results Responses from 357 podiatrists, 93 orthotists and 49 physiotherapists were included in the analysis. The results reveal statistically significant differences in employment and clinical arrangements, the clinical populations treated, and the nature and volume of foot orthoses caseload. Conclusion Podiatrists, orthotists and physiotherapists provide foot orthoses to important clinical populations in both a prevention and treatment capacity. Their working context, scope of practice and mix of clinical caseload differs significantly, although there are areas of overlap. Addressing variations in practice could align this collective workforce to national allied health policy

    Forensic child and Adolescent Psychiatry and mental health in Europe

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    Background When faced with the discovery of their child’s self-harm, mothers and fathers may re-evaluate their parenting strategies. This can include changes to the amount of support they provide their child and changes to the degree to which they control and monitor their child. Methods We conducted an in-depth qualitative study with 37 parents of young people who had self-harmed in which we explored how and why their parenting changed after the discovery of self-harm. Results Early on, parents often found themselves “walking on eggshells” so as not to upset their child, but later they felt more able to take some control. Parents’ reactions to the self-harm often depended on how they conceptualised it: as part of adolescence, as a mental health issue or as “naughty behaviour”. Parenting of other children in the family could also be affected, with parents worrying about less of their time being available for siblings. Many parents developed specific strategies they felt helped them to be more effective parents, such as learning to avoid blaming themselves or their child for the self-harm and developing new ways to communicate with their child. Parents were generally eager to pass their knowledge on to other people in the same situation. Conclusions Parents reported changes in their parenting behaviours after the discovery of a child’s self-harm. Professionals involved in the care of young people who self-harm might use this information in supporting and advising parents.</p
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