1,490 research outputs found

    Contextual information and assessor characteristics in complex question answering

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    The ciqa track investigates the role of interaction in answering complex questions: questions that relate two or more entities by some specified relationship. In our submission to the first ciqa track we were interested in the interplay between groups of variables: variables describing the question creators, the questions asked and the presentation of answers to the questions. We used two interaction forms - html questionnaires completed before answer assessment - to gain contextual information from the answer assessors to better understand what factors influence assessors when judging retrieved answers to complex questions. Our results indicate the importance of understanding the assessor's personal relationship to the question - their existing topical knowledge for example - and also the presentation of the answers - contextual information about the answer to aid in the assessment of the answer

    A Search for Wolf-Rayet Stars in the Small Magellanic Cloud

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    We conducted an extensive search for Wolf-Rayet stars (W-Rs) in the SMC, using the same interference filter imaging techniques that have proved successful in finding W-Rs in more distant members of the Local Group. Photometry of some 1.6 million stellar images resulted in some 20 good candidates, which we then examined spectroscopically. Two of these indeed proved to be newly found W-Rs, bringing the total known in the SMC from 9 to 11. Other finds included previously unknown Of-type stars (one as early as O5f?p)),the recovery of the Luminous Blue Variable S18, and the discovery of a previously unknown SMC symbiotic star. More important, however, is the fact that there does not exist a significant number of W-Rs waiting to be discovered in the SMC. The number of W-Rs in the SMC is a factor of 3 lower than in the LMC (per unit luminosity), and we argue this is the result of the SMC's low metallicity on the evolution of the most massive stars.Comment: Accepted by Astrophysical Journal. Postscript version available via ftp.lowell.edu/pub/massey/smcwr.ps.gz Revised version contains slightly revised spectral types for the Of stars but is otherwise unchange

    Discovery of Raman-scattered lines in the massive luminous emission-line star LHA 115-S 18

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    LHA 115-S 18 is a very peculiar emission-line star exhibiting the B[e] phenomenon. Located in the Small Magellanic Cloud, its spectrum shows features of an extremely wide range of excitation and ionization stages, extending from highly ionized atomic lines (Si IV, C IV, He II) in the UV and optical regions to molecular emission bands of CO and TiO in the optical and IR regions. The most distinguishing spectral characteristic of LHA 115-S 18 is the high variability detected in the He II {\lambda}4686 emission line, which can be a very conspicuous or completely invisible feature. In this work, we report on another peculiarity of LHA 115-S 18. From high-resolution optical spectra taken between 2000 and 2008, we discovered the appearance and strengthening of two emission features at {\lambda}6825 \AA, and {\lambda}7082 \AA,, which we identified as Raman-scattered lines. This is the first time these lines have been detected in the spectrum of a massive luminous B[e] star. As the classification of LHA 115-S 18 is highly controversial, we discuss how the discovery of the appearance of Raman-scattered lines in this peculiar star might help us to solve this puzzle.Comment: Letter accepted for publication in MNRAS. 5 pages, 3 figure

    Intra-assessor consistency in question answering

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    In this paper we investigate the consistency of answer assessment in a complex question answering task examining features of assessor consistency, types of answers and question type

    The Massive Wolf-Rayet Binary SMC WR7

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    We present a study of optical spectra of the Wolf--Rayet star AzV 336a (= SMC WR7) in the Small Magellanic Cloud. Our study is based on data obtained at several Observatories between 1988 and 2001. We find SMC WR7 to be a double lined WN+O6 spectroscopic binary with an orbital period of 19.56 days. The radial velocities of the He absorption lines of the O6 component and the strong He{\sc ii} emission at λ\lambda4686\AA of the WN component describe antiphased orbital motions. However, they show a small phase shift of \sim 1 day. We discuss possible explanations for this phase shift. The amplitude of the radial velocity variations of He {\sc ii} emission is twice that of the absorption lines. The binary components have fairly high minimum masses, \sim 18 \modot and 34 \modot for the WN and O6 components, respectively.Comment: Accepted by MNRA

    Fluid resuscitation in adults with severe burns at risk of secondary abdominal compartment syndrome—An evidence based systematic review

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    Background: Secondary abdominal compartment syndrome (sACS) in adults with severe burns is commonly unsuspected, can be rapidly fatal and seriously compromises the reliability of urine output as an indicator of perfusion and resuscitation status. Current literature lacks an exhaustive, evidence-based review critically appraising all retrieved literature on which clinical decisions may be based. Methods: The evidence on three inter-related concepts was evaluated: fluid-volume management and its contribution to sACS; the role of urinary bladder pressure monitoring; and awareness of the burns community to sACS. Literature published over the last ten years across the major databases was retrieved, and the search strategy was fully reported to reduce the retrieval bias ubiquitous in previous literature. Each article was individually appraised and classified into a framework of evidence, enabling the formulation of specific, graded recommendations. Results: Current best evidence supports recommendations to reduce fluid-volume administered through use of colloids or hypertonic saline especially if the projected resuscitation volume surpasses a ‘volume ceiling’. Continuous intra-vesical monitoring is recommended: to guide fluid resuscitation for early diagnosis of sACS; and as a guide to reliability of urine output as indicator of organ perfusion. A priming volume of 75 cm3 or less is recommended. Conclusion: Fluid resuscitation volume is causative to sACS, especially once a predetermined maxima is reached. Continuous intra-vesical pressure monitoring is a cheap, reliable, userfriendly monitoringmethod recommended in high-risk patients. Poor awareness among the burns community requires urgent dissemination of evidence based information

    CORF3D contour maps with application to Holstein cattle recognition using RGB and thermal images

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    Livestock management involves the monitoring of farm animals by tracking certain physiological and phenotypical characteristics over time. In the dairy industry, for instance, cattle are typically equipped with RFID ear tags. The corresponding data (e.g. milk properties) can then be automatically assigned to the respective cow when they enter the milking station. In order to move towards a more scalable, affordable, and welfare-friendly approach, automatic non-invasive solutions are more desirable. Thus, a non-invasive approach is proposed in this paper for the automatic identification of individual Holstein cattle from the side view while exiting a milking station. It considers input images from a thermal-RGB camera. The thermal images are used to delineate the cow from the background. Subsequently, any occluding rods from the milking station are removed and inpainted with the fast marching algorithm. Then, it extracts the RGB map of the segmented cattle along with a novel CORF3D contour map. The latter contains three contour maps extracted by the Combination of Receptive Fields (CORF) model with different strengths of push-pull inhibition. This mechanism suppresses noise in the form of grain type texture. The effectiveness of the proposed approach is demonstrated by means of experiments using a 5-fold and a leave-one day-out cross-validation on a new data set of 3694 images of 383 cows collected from the Dairy Campus in Leeuwarden (the Netherlands) over 9 days. In particular, when combining RGB and CORF3D maps by late fusion, an average accuracy of was obtained for the 5-fold cross validation and for the leave–one day–out experiment. The two maps were combined by first learning two ConvNet classification models, one for each type of map. The feature vectors in the two FC layers obtained from training images were then concatenated and used to learn a linear SVM classification model. In principle, the proposed approach with the novel CORF3D contour maps is suitable for various image classification applications, especially where grain type texture is a confounding variable

    Semi-supervised prediction of protein interaction sentences exploiting semantically encoded metrics

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    Protein-protein interaction (PPI) identification is an integral component of many biomedical research and database curation tools. Automation of this task through classification is one of the key goals of text mining (TM). However, labelled PPI corpora required to train classifiers are generally small. In order to overcome this sparsity in the training data, we propose a novel method of integrating corpora that do not contain relevance judgements. Our approach uses a semantic language model to gather word similarity from a large unlabelled corpus. This additional information is integrated into the sentence classification process using kernel transformations and has a re-weighting effect on the training features that leads to an 8% improvement in F-score over the baseline results. Furthermore, we discover that some words which are generally considered indicative of interactions are actually neutralised by this process

    The influence of massive stars in the interstellar medium of IC 1613: the supernova remnant S8 and the nebula S3 associated with a WO star

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    We present a detailed kinematical analysis of two selected nebulae in the Local Group irregular galaxy IC 1613. The nebulae are: S8, the only known supernova remnant in this galaxy, and S3, a Wolf-Rayet nebula associated with the only WO star in this galaxy. For S8, we have obtained and analyzed its radial velocity field, where we found complex profiles which can be fitted by several velocity components. These profiles also show the presence of high velocity, low density gas. From this, we have obtained the expansion velocity, estimated the preshock density and calculated the basic kinematical parameters of this SNR. We suggest that in S8 we are seing a SNR partially hidden by dust. This suggestion comes from the fact that the SNR is located between two superbubbles where a ridge of obscured material unveils the existence of dust. Moreover, we show that this hypothesis prevails when energetic arguments are taken into account. In the case of S3, this nebula shows bipolar structure. By means of its kinematics, we have analyzed its two lobes, the ``waist'', as well as its relation with the nearest superbubbles. For the first time we are able to see closed the NW lobe, showing a clover leaf shape. This fact allows a better quantitative knowledge of the nebula as a whole. Furthermore, we found evidence of an expansion motion in the NW lobe. In the light of our results, we can express that these nebulae are the product of very massive stellar evolution. It is surprising the influence these stars still have in shaping their surrounding gas, and on the energy liberation towards the interstellar medium of this galaxy.Comment: Accepted for publication in the Astronomical Journal, July issue. 11 pages, 12 figures. High resolution figures can be found at http://www.inaoep.mx/~mago/PAPERS/AJ

    VLT spectroscopy of blue supergiants in IC 1613

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    We present multi-object spectroscopy of young, massive stars in the Local Group galaxy IC 1613. We provide the spectral classification and a detailed spectral catalog for 54 OBA stars in this galaxy. The majority of the photometrically selected sample is composed of B- and A-type supergiants. The remaining stars include early O-type dwarfs and the only Wolf-Rayet star known in this galaxy. Among the early B stars we have serendipitously uncovered 6 Be stars, the largest spectroscopically confirmed sample of this class of objects beyond the Magellanic Clouds. We measure chemical abundances for 9 early-B supergiants, and find a mean oxygen abundance of 12+log(O/H)=7.90 +/- 0.08. This value is consistent with the result we obtain for two HII regions in which we detect the temperature-sensitive [OIII]4363 auroral line.Comment: 17 pages, accepted for publication in the Astrophysical Journa
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