329 research outputs found

    HDE 233517: Lithium and Excess Infrared Emission in Giant Stars

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    Recent studies have identified a small class of moderately rapidly rotating, chromospherically active, single giants, some of which are lithium rich. We present evidence suggesting the peculiar K-type star HDE 233517 is one such object. Previously, HDE 233517 has been suggested to be a young star, consistent with its large far-infrared excess and our log ε(Li) ~ 3.3. However, our high-resolution spectroscopic observations show it is likely a single, post-main-sequence K2 giant with v sin i = 15 km s-1 and modest Ca II H and K emission. The giant status of HDE 233517 is determined directly from luminosity-sensitive line ratios and a lack of significant line wings, and is further supported by a large radial velocity (46.5 km s-1), small proper motion, and the presence of interstellar absorption features. Interpretation of the data in the context of a recent mass outflow model for giant stars proposed by de la Reza and coworkers indicates that HDE 233517 has the largest mass-loss rate, ~3 × 10-7 M☉ yr-1, of any known luminosity class III giant. We suggest that the processes causing rapid rotation, large lithium abundance, and infrared excess are triggered at the base of the giant branch when the convection zone reaches the rapidly rotating core of low-mass stars

    Consensus Panel for Assessing Usability and Acceptability of Mobile Health Autism Screeners

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    Abstract: Background: Parents go online to assess whether their child has symptoms of autism. Though early autism identification is important, language, cultural, and technological barriers may impede equitable access to online autism screening tools. Objective: To create consensus recommendations for equitable design of autism screening apps and websites using an online panel of parents, autistic self-advocates, health and educational providers, autism researchers, and online screening tool developers. Methods: We invited 6 parents (4 of autistic and 2 of typically-developing children), 2 autistic adults, 3 early intervention providers, 3 pediatric primary care providers, and 3 autism online screening app/website developers to participate in a consensus panel, using a Modified Delphi design. The panel includes 3 asynchronous rounds of online discussion and voting and one live online videoconference. Participants initially received a multimedia summary (written summaries, videos, interactive polls) of prior research on screening tool usability/accessibility, and a list of preliminary design recommendations. In each round, participants discuss recommendations, make suggestions for alternative or additional recommendations, and vote for most important recommendations. The list of recommendations is iteratively revised and reduced after each round. In the final videoconference discussion, a consensus guideline will be created based on the recommendations vetted by panel participants. Anticipated results: The consensus panel is currently in process. Some example recommendations include: Screener should be accessible on multiple platforms (e.g., iOS, Android) parents should be able to complete screener inminutes Conclusion: A multidisciplinary panel can help translate research findings to actionable recommendations for equitable autism screening

    Tycho 2 stars with infrared excess in the MSX Point Source Catalogue

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    Stars of all evolutionary phases have been found to have excess infrared emission due to the presence of circumstellar material. To identify such stars, we have positionally correlated the infrared MSX point source catalogue and the Tycho 2 optical catalogue. A near/mid infrared colour criteria has been developed to select infrared excess stars. The search yielded 1938 excess stars, over half (979) have never previously been detected by IRAS. The excess stars were found to be young objects such as Herbig Ae/Be and Be stars, and evolved objects such as OH/IR and carbon stars. A number of B type excess stars were also discovered whose infrared colours could not be readily explained by known catalogued objects.Comment: Added Comment: 16 pages, 9 figures, accepted for publication in MNRA

    Evidence for binarity in the bipolar planetary nebulae A79, He2-428 and M1-91

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    We present low and high resolution long-slit spectra of three bipolar planetary nebulae (PNe) with bright central cores: A79, He2-428 and M1-91. He2-428 and M1-91 have high density (from 10^3.3 to 10^6.5 cm^-3) unresolved nebular cores that indicate that strong mass loss/exchange phenomena are occurring close to their central stars. An F0 star is found at the centre of symmetry of A79; its reddening and distance are consistent with the association of the star with the nebula. The spectrum of the core of He2-428 shows indications of the presence of a hot star with red excess emission, probably arising in a late-type companion. A79 is one of the richest PNe in N and He, the abundances of M1-91 are at the lower end of the range spanned by bipolar PNe, and He2-428 shows very low abundances, similar to those measured for halo PNe. The extended nebulae of A79 and He2-428 have inclined equatorial rings expanding at a velocity of approx. 15 km/s, with kinematical ages 10^4 yr. The association of these aged, extended nebulae with a dense nebular core (He2-428) or a relatively late type star (A79) is interpreted as evidence for the binarity of their nuclei.Comment: 13 pages including 8 tables. A&A accepted; also available at http://www.iac.es/publicaciones/preprints.htm

    Adolescent Dose and Ratings of an Internet-Based Depression Prevention Program: A Randomized Trial of Primary Care Physician Brief Advice versus a Motivational Interview

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    Background—Internet-based interventions for education and behavior change have proliferated, but most adolescents may not be sufficiently motivated to engage in Internet-based behavior change interventions. We sought to determine how two different forms of primary care physician engagement, brief advice (BA) versus motivational interview (MI), could enhance participation outcomes in an Internet-based depression prevention intervention. Methods—Eighty-three adolescents at risk for developing major depression were recruited by screening in primary care and randomized to two groups: BA (1–2 minutes) + Internet program versus MI (10–15 minutes) + Internet program. We compared measures of participation and satisfaction for the two groups for a minimum of 12 months after enrollment. Results—Both groups engaged the site actively (MI: 90% versus BA: 78%, p=0.12). MI had significantly higher levels of engagement than BA for measures including total time on site (143.7 minutes versus 100.2 minutes, p=0.03), number of sessions (8.16 versus 6.00, p=0.04), longer duration of session activity on Internet site (46.2 days versus 29.34 days, p=0.04), and with more characters typed into exercises (3532 versus 2004, p=0.01). Adolescents in the MI group reported higher trust in their physician (4.18 versus 3.74, p=0.05) and greater satisfaction with the Internet- based component (7.92 versus 6.66, p=0.01). Conclusions—Primary care engagement, particularly using motivational interviewing, may increase Internet use dose, and some elements enhance and intensify adolescent use of an Internet- based intervention over a one to two month period. Primary care engagement may be a useful method to facilitate adolescent involvement in preventive mental health interventions

    Multi-wavelength diagnostic properties of Galactic Planetary Nebulae detected by GLIMPSE-I

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    We uniformly analyze 136 optically detected PNe and candidates from the GLIMPSE-I survey in order to to develop robust, multi-wavelength, classification criteria to augment existing diagnostics and provide pure PN samples. PNe represent powerful astrophysical probes. They are important dynamical tracers, key sources of ISM chemical enrichment, windows into late stellar evolution, and potent cosmological yardsticks. But their utility depends on separating them unequivocally from the many nebular mimics which can strongly resemble bona fide PNe in traditional optical images and spectra. We merge new PNe from the carefully evaluated, homogeneous MASH-I and MASH-II surveys, which offer a wider evolutionary range of PNe than hitherto available, with previously known PNe classified by SIMBAD. Mid-infrared (MIR) measurements vitally complement optical data because they reveal other physical processes and morphologies via fine-structure lines, molecular bands and dust. MIR colour-colour planes, optical emission line ratios and radio fluxes show the unambiguous classification of PNe to be complex, requiring all available evidence. Statistical trends provide predictive value and we offer quantitative MIR criteria to determine whether an emission nebula is most likely to be a PN or one of the frequent contaminants such as compact HII regions or symbiotic systems. Prerequisites have been optical images and spectra but MIR morphology, colours, environment and a candidate's MIR/radio flux ratio provide a more rigorous classification. Our ultimate goal is to recognize PNe using only MIR and radio characteristics, enabling us to trawl for PNe effectively even in heavily obscured regions of the Galaxy.Comment: 32 pages, 18 figures, 10 table

    Speech and language therapy for aphasia following stroke

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    Background  Aphasia is an acquired language impairment following brain damage that affects some or all language modalities: expression and understanding of speech, reading, and writing. Approximately one third of people who have a stroke experience aphasia.  Objectives  To assess the effects of speech and language therapy (SLT) for aphasia following stroke.  Search methods  We searched the Cochrane Stroke Group Trials Register (last searched 9 September 2015), CENTRAL (2015, Issue 5) and other Cochrane Library Databases (CDSR, DARE, HTA, to 22 September 2015), MEDLINE (1946 to September 2015), EMBASE (1980 to September 2015), CINAHL (1982 to September 2015), AMED (1985 to September 2015), LLBA (1973 to September 2015), and SpeechBITE (2008 to September 2015). We also searched major trials registers for ongoing trials including ClinicalTrials.gov (to 21 September 2015), the Stroke Trials Registry (to 21 September 2015), Current Controlled Trials (to 22 September 2015), and WHO ICTRP (to 22 September 2015). In an effort to identify further published, unpublished, and ongoing trials we also handsearched theInternational Journal of Language and Communication Disorders(1969 to 2005) and reference lists of relevant articles, and we contacted academic institutions and other researchers. There were no language restrictions.  Selection criteria  Randomised controlled trials (RCTs) comparing SLT (a formal intervention that aims to improve language and communication abilities, activity and participation) versus no SLT; social support or stimulation (an intervention that provides social support and communication stimulation but does not include targeted therapeutic interventions); or another SLT intervention (differing in duration, intensity, frequency, intervention methodology or theoretical approach).  Data collection and analysis  We independently extracted the data and assessed the quality of included trials. We sought missing data from investigators.  Main results  We included 57 RCTs (74 randomised comparisons) involving 3002 participants in this review (some appearing in more than one comparison). Twenty-seven randomised comparisons (1620 participants) assessed SLT versus no SLT; SLT resulted in clinically and statistically significant benefits to patients' functional communication (standardised mean difference (SMD) 0.28, 95% confidence interval (CI) 0.06 to 0.49, P = 0.01), reading, writing, and expressive language, but (based on smaller numbers) benefits were not evident at follow-up. Nine randomised comparisons (447 participants) assessed SLT with social support and stimulation; meta-analyses found no evidence of a difference in functional communication, but more participants withdrew from social support interventions than SLT. Thirty-eight randomised comparisons (1242 participants) assessed two approaches to SLT. Functional communication was significantly better in people with aphasia that received therapy at a high intensity, high dose, or over a long duration compared to those that received therapy at a lower intensity, lower dose, or over a shorter period of time. The benefits of a high intensity or a high dose of SLT were confounded by a significantly higher dropout rate in these intervention groups. Generally, trials randomised small numbers of participants across a range of characteristics (age, time since stroke, and severity profiles), interventions, and outcomes.  Authors' conclusions  Our review provides evidence of the effectiveness of SLT for people with aphasia following stroke in terms of improved functional communication, reading, writing, and expressive language compared with no therapy. There is some indication that therapy at high intensity, high dose or over a longer period may be beneficial. HIgh-intensity and high dose interventions may not be acceptable to all
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