24 research outputs found

    The AllWISE Motion Survey, Part 2

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    We use the AllWISE Data Release to continue our search for WISE-detected motions. In this paper, we publish another 27,846 motion objects, bringing the total number to 48,000 when objects found during our original AllWISE motion survey are included. We use this list, along with the lists of confirmed WISE-based motion objects from the recent papers by Luhman and by Schneider et al. and candidate motion objects from the recent paper by Gagne et al. to search for widely separated, common-proper-motion systems. We identify 1,039 such candidate systems. All 48,000 objects are further analyzed using color-color and color-mag plots to provide possible characterizations prior to spectroscopic follow-up. We present spectra of 172 of these, supplemented with new spectra of 23 comparison objects from the literature, and provide classifications and physical interpretations of interesting sources. Highlights include: (1) the identification of three G/K dwarfs that can be used as standard candles to study clumpiness and grain size in nearby molecular clouds because these objects are currently moving behind the clouds, (2) the confirmation/discovery of several M, L, and T dwarfs and one white dwarf whose spectrophotometric distance estimates place them 5-20 pc from the Sun, (3) the suggestion that the Na 'D' line be used as a diagnostic tool for interpreting and classifying metal-poor late-M and L dwarfs, (4) the recognition of a triple system including a carbon dwarf and late-M subdwarf, for which model fits of the late-M subdwarf (giving [Fe/H] ~ -1.0) provide a measured metallicity for the carbon star, and (5) a possible 24-pc-distant K5 dwarf + peculiar red L5 system with an apparent physical separation of 0.1 pc.Comment: 62 pages with 80 figures, accepted for publication in The Astrophysical Journal Supplement Series, 23 Mar 2016; second version fixes a few small typos and corrects the footnotes for Table

    Discovery of Two Nearby, Peculiar L Dwarfs from the 2MASS Proper Motion Survey: Young or Metal-Rich?

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    We present the discovery of two nearby L dwarfs from our 2MASS proper motion search, which uses multi-epoch 2MASS observations covering ~4700 square degrees of sky. 2MASS J18212815+1414010 and 2MASS J21481628+4003593 were overlooked by earlier surveys due to their faint optical magnitudes and their proximity to the Galactic Plane (10 degrees < |b| < 15 degrees). Assuming that both dwarfs are single, we derive spectrophotometric distances of ~10 pc, thus increasing the number of known L dwarfs within 10 pc to 10. In the near-infrared, 2MASS J21481628+4003593 shows a triangular-shaped H-band spectrum, strong CO absorption, and a markedly red J-Ks color (2.38+/-0.06) for its L6 optical spectral type. 2MASS J18212815+1414010 also shows a triangular-shaped H-band spectrum and a slightly red J-Ks color (1.78+/-0.05) for its L4.5 optical spectral type. Both objects show strong silicate absorption at 9-11 microns. Cumulatively, these features imply an unusually dusty photosphere for both of these objects. We examine several scenarios to explain the underlying cause for their enhanced dust content and find that a metal-rich atmosphere or a low-surface gravity are consistent with these results. 2MASS J18212815+1414010 may be young (and therefore have a low-surface gravity) based on its low tangential velocity of 10 km/s. On the other hand, 2MASS J21481628+4003593 has a high tangential velocity of 62 km/s and is therefore likely old. Hence, high metallicity and low-surface gravity may lead to similar effects.Comment: 9 pages, 4 tables, 13 figures. Accepted to Ap

    Discoveries from a Near-infrared Proper Motion Survey using Multi-epoch 2MASS Data

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    We have conducted a 4030-square-deg near-infrared proper motion survey using multi-epoch data from the Two Micron All-Sky Survey (2MASS). We find 2778 proper motion candidates, 647 of which are not listed in SIMBAD. After comparison to DSS images, we find that 107 of our proper motion candidates lack counterparts at B-, R-, and I-bands and are thus 2MASS-only detections. We present results of spectroscopic follow-up of 188 targets that include the infrared-only sources along with selected optical-counterpart sources with faint reduced proper motions or interesting colors. We also establish a set of near-infrared spectroscopic standards with which to anchor near-infrared classifications for our objects. Among the discoveries are six young field brown dwarfs, five "red L" dwarfs, three L-type subdwarfs, twelve M-type subdwarfs, eight "blue L" dwarfs, and several T dwarfs. We further refine the definitions of these exotic classes to aid future identification of similar objects. We examine their kinematics and find that both the "blue L" and "red L" dwarfs appear to be drawn from a relatively old population. This survey provides a glimpse of the kinds of research that will be possible through time-domain infrared projects such as the UKIDSS Large Area Survey, various VISTA surveys, and WISE, and also through z- or y-band enabled, multi-epoch surveys such as Pan-STARRS and LSST.Comment: To appear in the September 2010 issue of The Astrophysical Journal, Supplement Serie

    Correlation analysis of the transcriptome of growing leaves with mature leaf parameters in a maize RIL population

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    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

    SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues

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    Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types

    TRY plant trait database – enhanced coverage and open access

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    Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    A first update on mapping the human genetic architecture of COVID-19

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    The Enigmatic Brown Dwarf WISEA J153429.75-104303.3 (a.k.a. "The Accident")

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    Continued follow-up of WISEA J153429.75−104303.3, announced in Meisner et al., has proven it to have an unusual set of properties. New imaging data from Keck/MOSFIRE and HST/WFC3 shows that this object is one of the few faint proper motion sources known with J − ch2 >8 mag, indicating a very cold temperature consistent with the latest known Y dwarfs. Despite this, it has W1−W2 and ch1−ch2 colors ~1.6 mag bluer than a typical Y dwarf. A new trigonometric parallax measurement from a combination of WISE, Spitzer, and HST astrometry confirms a nearby distance of 16.3−1.2+1.4{16.3}_{-1.2}^{+1.4} pc and a large transverse velocity of 207.4 ± 15.9 km s−1. The absolute J, W2, and ch2 magnitudes are in line with the coldest known Y dwarfs, despite the highly discrepant W1−W2 and ch1−ch2 colors. We explore possible reasons for the unique traits of this object and conclude that it is most likely an old, metal-poor brown dwarf and possibly the first Y subdwarf. Given that the object has an HST F110W magnitude of 24.7 mag, broadband spectroscopy and photometry from JWST are the best options for testing this hypothesis

    Evaluating tactile feedback in robotic surgery for potential clinical application using an animal model

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    INTRODUCTION: The aims of this study were to evaluate 1) grasping forces with the application of a tactile feedback system in vivo 2) the incidence of tissue damage incurred during robotic tissue manipulation. Robotic-assisted minimally invasive surgery has been shown to be beneficial in a variety of surgical specialties, particularly radical prostatectomy. This innovative surgical tool offers advantages over traditional laparoscopic techniques, such as improved wrist-like maneuverability, stereoscopic video displays, and scaling of surgical gestures to increase precision. A widely cited disadvantage associated with robotic systems is the absence of tactile feedback. METHODS AND PROCEDURE: Nineteen subjects were categorized into two groups: 5 experts (six or more robotic cases) and 14 novices (five cases or less). The subjects used the da Vinci with integrated tactile feedback to run porcine bowel in the following conditions: (T1: deactivated tactile feedback; T2: activated tactile feedback; and T3: deactivated tactile feedback). The grasping force, incidence of tissue damage, and the correlation of grasping force and tissue damage were analyzed. Tissue damage was evaluated both grossly and histologically by a pathologist blinded to the sample. RESULTS: Tactile feedback resulted in significantly decreased grasping forces for both experts and novices (P < 0.001 in both conditions). The overall incidence of tissue damage was significantly decreased in all subjects (P < 0.001). A statistically significant correlation was found between grasping forces and incidence of tissue damage (P = 0.008). The decreased forces and tissue damage were retained through the third trial when the system was deactivated (P > 0.05 in all subjects). CONCLUSIONS: The in vivo application of integrated tactile feedback in the robotic system demonstrates significantly reduced grasping forces, resulting in significantly less tissue damage. This tactile feedback system may improve surgical outcomes and broaden the use of robotic-assisted minimally invasive surgery
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