2,200 research outputs found

    A framework to combine low- and high-resolution spectroscopy for the atmospheres of transiting exoplanets

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    Current observations of the atmospheres of close-in exoplanets are predominantly obtained with two techniques: low-resolution spectroscopy with space telescopes and high-resolution spectroscopy from the ground. Although the observables delivered by the two methods are in principle highly complementary, no attempt has ever been made to combine them, perhaps due to the different modeling approaches that are typically used in their interpretation. Here we present the first combined analysis of previously-published dayside spectra of the exoplanet HD 209458b obtained at low resolution with HST/WFC3 and Spitzer/IRAC, and at high resolution with VLT/CRIRES. By utilizing a novel retrieval algorithm capable of computing the joint probability distribution of low- and high-resolution spectra, we obtain tight constraints on the chemical composition of the planet's atmosphere. In contrast to the WFC3 data, we do not confidently detect H2O at high spectral resolution. The retrieved water abundance from the combined analysis deviates by 1.9 sigma from the expectations for a solar-composition atmosphere in chemical equilibrium. Measured relative molecular abundances of CO and H2O strongly favor an oxygen-rich atmosphere (C/O<1 at 3.5 sigma) for the planet when compared to equilibrium calculations including O rainout. From the abundances of the seven molecular species included in this study we constrain the planet metallicity to 0.1-1.0x the stellar value (1 sigma). This study opens the way to coordinated exoplanet surveys between the flagship ground- and space-based facilities, which ultimately will be crucial for characterizing potentially-habitable planets.Comment: 7 pages, 5 figures, accepted for publication in ApJL. Section 4 largely updated from previous version, Figure 2 updated to contain information on the T-p profil

    Detecting Distracted Driving with Deep Learning

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    © Springer International Publishing AG 2017Driver distraction is the leading factor in most car crashes and near-crashes. This paper discusses the types, causes and impacts of distracted driving. A deep learning approach is then presented for the detection of such driving behaviors using images of the driver, where an enhancement has been made to a standard convolutional neural network (CNN). Experimental results on Kaggle challenge dataset have confirmed the capability of a convolutional neural network (CNN) in this complicated computer vision task and illustrated the contribution of the CNN enhancement to a better pattern recognition accuracy.Peer reviewe

    Additions and Range Extensions to the Vascular Plant Flora of the Continental Northwest Territories and Nunavut, Canada, II

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    Based on field reconnaissance since the publication of Flora of the Continental Northwest Territories in 1980, particularly in the District of Keewatin and northeastern District of Mackenzie (Nunavut) and Nahanni National Park, information is provided on geographically significant plant occurrences. One new taxon, Polemonium boreale forma albiflorum, is described, fourteen native taxa are reported as new to the region: Carex hoodii, C. microptera, C. petasata, Corispermum hookeri, C. ochotense, Danthonia spicata, Draba stenoloba, Erysisnum coarctatum, Halenia deflexa, Polygonum fowleri, P. ramosissimum, Salix rotundifolia ssp. rotundifolia, Silene uralensis ssp. ogilviensis, and Vaccinium ovalifolium. Five introduced taxa, Crepis tectorum, Corispermum villosum, Deschampsia elongata, D. incisa var. incisa, and Medicago sativa ssp. falcata are new to the flora of the region. Two native taxa, Danthonia intermedia and Potentilla porsildiorum are deleted from the flora and Ranunculus aquatilis var hispidulus is placed in synonymy. Significant range extensions for 125 native and one introduced taxon are included

    Radial Velocity Observations of the Extended Lunar Sodium Tail

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    We report the first velocity resolved sodium 5889.950 Å line profile observations of the lunar sodium tail observed in the anti-lunar direction near new Moon. These observations were made on 29 March 2006, 27 April 2006 and 28 April 2006 from Pine Bluff (WI) observatory with a double etalon Fabry-Perot spectrometer at a resolving power of ∼80,000. The observations were made within 2–14 hours from new Moon, pointing near the anti-lunar point. The average observed radial velocity of the lunar sodium tail in the vicinity of the anti-lunar point for the three nights reported was 12.4 km s−1 (from geocentric zero). The average Doppler width of a single Gaussian fit to the emission line was 7.6 km s−1. In some cases the line profile appears asymmetric, with excess lunar sodium emission at higher velocity (∼18 km s−1 from geocentric zero) that is not accounted for by our single Gaussian fit to the emission

    Adult psychosocial outcomes of children with specific language impairment, pragmatic language impairment and autism

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    Background: The few studies that have tracked children with developmental language disorder to adulthood have found that these individuals experience considerable difficulties with psychosocial adjustment (for example, academic, vocational and social aptitude). Evidence that some children also develop autistic symptomatology over time has raised suggestions that developmental language disorder may be a high-functioning form of an autism spectrum disorder (ASD). It is not yet clear whether these outcomes vary between individuals with different subtypes of language impairment

    Qualitative aspects of developmental language impairment relate to language and literacy outcome in adulthood

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    Background: Developmental language disorder is a heterogeneous diagnostic category. Little research has compared the long-term outcomes of children with different subtypes of language impairment
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