388 research outputs found

    Do the Herschel cold clouds in the Galactic halo embody its dark matter?

    Full text link
    Recent Herschel/SPIRE maps of the Small and Large Magellanic Clouds (SMC, LMC) exhibit in each thousands of clouds. Observed at 250 microns, they must be cold, T ~ 15 K, hence the name "Herschel cold clouds" (HCCs). From the observed rotational velocity profile and the assumption of spherical symmetry, the Galactic mass density is modeled in a form close to that of an isothermal sphere. If the HCCs constitute a certain fraction of it, their angular size distribution has a specified shape. A fit to the data deduced from the SMC/LMC maps supports this and yields for their radius 2.5 pc, with a small change when allowing for a spread in HCC radii. There are so many HCCs that they will make up all the missing Halo mass density if there is spherical symmetry and their average mass is of order 15,000 Mo. This compares well with the Jeans mass of circa 40,000 Mo and puts forward that the HCCs are in fact Jeans clusters, constituting all the Galactic dark matter and much of its missing baryons, a conclusion deduced before from a different field of the sky (Nieuwenhuizen, Schild and Gibson 2011). A preliminary analysis of the intensities yields that the Jeans clusters themselves may consist of some billion MACHOs of a few dozen Earth masses. With a size of dozens of solar radii, they would mostly obscure stars in the LMC, SMC and towards the Galactic center, and may thus have been overlooked in microlensing.Comment: Revised and corrected version, matches published version. Conclusions unchange

    A comparison of clinical communication skills between two groups of final-year medical students with different levels of communication skills training

    Get PDF
    Training in communication skills is prominent in many undergraduate medical programmes. In South Africa, training in this highly complex skill is developing rapidly, especially against the backdrop of a multilingual and multicultural society. Little work has been done locally to evaluate which training works best in our context. In 1999, the Stellenbosch University Faculty of Health Sciences introduced a new curriculum that included considerably more communication skills training. The aim of this study was to assess and compare the communication skills used in the consultations of two groups of final-year medical students who had different levels of communication skills training in order to make recommendations on appropriate changes in this training. Methods Standardised doctor-patient interviews performed by students during the final-year examinations in 2003 and 2004 were videotaped. These were assessed by two independent, blinded evaluators using an abbreviated version of the Calgary- Cambridge communication guide for skills not done (0) and done (1). The data was analysed using STATISTICA 7. Results A total of 161 interviews were analysed. Both groups performed well (mean = 1) in listening to the opening question, encouraging the patients to tell their story, and demonstrating appropriate non-verbal behaviour. However, ending the session by summarising and clarifying the plan was poorly performed (mean = 0.4). The 2004 group was statistically significantly better in structuring the consultation by using signposting (p value = 0.02). Conclusion There are a number of influences on the effectiveness of communication skills training, including issues around language, culture and gender, student attitudes, the significance of communication skills training in the programme and, most importantly, the integration of this training into the curriculum as a whole. Merely adding more time to communication skills training does not seem to be the answer. Incorporating a wider range of training methods is also important. The results of this impact study acted as an impetus for innovative curriculum development in our faculty, leading to the development of a comprehensive clinical model and a “golden thread” for communication skills in the curriculum to ensure the longitudinal integration of communication skills. South African Family Practice Vol. 49 (7) 2007: pp. 1

    Neural Coreference Resolution for Dutch Parliamentary Documents with the DutchParliament Dataset

    Get PDF
    The task of coreference resolution concerns the clustering of words and phrases referring to the same entity in text, either in the same document or across multiple documents. The task is challenging, as it concerns elements of named entity recognition and reading comprehension, as well as others. In this paper, we introduce DutchParliament, a new Dutch coreference resolution dataset obtained through the manual annotation of 74 government debates, expanded with a domain-specific class. In contrast to existing datasets, which are often composed of news articles, blogs or other documents, the debates in DutchParliament are transcriptions of speech, and therefore offer a unique structure and way of referencing compared to other datasets. By constructing and releasing this dataset, we hope to facilitate the research on coreference resolution in niche domains, with different characteristics than traditional datasets. The DutchParliament dataset was compared to SoNaR-1 and RiddleCoref, two other existing Dutch coreference resolution corpora, to highlight its particularities and differences from existing datasets. Furthermore, two coreference resolution models for Dutch, the rule-based DutchCoref model and the neural e2eDutch model, were evaluated on the DutchParliament dataset to examine their performance on the DutchParliament dataset. It was found that the characteristics of the DutchParliament dataset are quite different from that of the other two datasets, although the performance of the e2eDutch model does not seem to be significantly affected by this. Furthermore, experiments were conducted by utilizing the metadata present in the DutchParliament corpus to improve the performance of the e2eDutch model. The results indicate that the addition of available metadata about speakers has a beneficial effect on the performance of the model, although the addition of the gender of speakers seems to have a limited effect

    Entity Linking in the ParlaMint Corpus

    Get PDF
    The ParlaMint corpus is a multilingual corpus consisting of the parliamentary debates of seventeen European countries over a span of roughly five years. The automatically annotated versions of these corpora provide us with a wealth of linguistic information, including Named Entities. In order to further increase the research opportunities that can be created with this corpus, the linking of Named Entities to a knowledge base is a crucial step. If this can be done successfully and accurately, a lot of additional information can be gathered from the entities, such as political stance and party affiliation, not only within countries but also between the parliaments of different countries. However, due to the nature of the ParlaMint dataset, this entity linking task is challenging. In this paper, we investigate the task of linking entities from ParlaMint in different languages to a knowledge base, and evaluating the performance of three entity linking methods. We will be using DBPedia spotlight, WikiData and YAGO as the entity linking tools, and evaluate them on local politicians from several countries. We discuss two problems that arise with the entity linking in the ParlaMint corpus, namely inflection, and aliasing or the existence of name variants in text. This paper provides a first baseline on entity linking performance on multiple multilingual parliamentary debates, describes the problems that occur when attempting to link entities in ParlaMint, and makes a first attempt at tackling the aforementioned problems with existing methods

    Expecting the unexpected : Temporal expectation increases the flash-grab effect

    Get PDF
    Acknowledgments EvH, TB, KC, and HH were supported by the Australian Government through the Australian Research Council's Discovery Projects funding scheme (project DP180102268). PC was supported by grants from Dartmouth College and from Natural Sciences and Engineering Research Council Canada.Peer reviewedPublisher PD

    Prijzen van landbouwgrond in en om VINEX-locaties

    Get PDF
    Studie in opdracht van het Directoraat-Generaal voor de VolksHuisvesting van het ministerie van Verkeer, Ruimtelijke Ordening en Milieu. De studie laat zien dat er met behulp van gegevens van het Kadaster betrouwbare overzichten van prijzen van landbouwgrond in VINEX-gemeenten kunnen worden opgesteld. Zowel per BON-gebied (Besturen Op Niveau), zoals vastgesteld binnen de kaderwet Bestuur en Verandering als per cluster van overige Stadsgewesten, zoals aangeduid in de bijlage van het Besluit Locatiegebonden Subsidies (BLS). De prijzen van landbouwgronden in VINEX-locaties en VINEX-gemeenten blijken tussen 1993 en 1997 met 60% te zijn gestegen tot gemiddeld 55 gulden per vierkante meter. In dezelfde periode stegen de prijzen van agrarisch bestemde gronden met 30% tot 5 gulden per vierkante meter
    corecore