1,720,978 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Combining learning and constraints for genome-wide protein annotation
Full text linkBackgroundThe advent of high-throughput experimental techniques paved the way to genome-wide computational analysis and predictive annotation studies. When considering the joint annotation of a large set of related entities, like all proteins of a certain genome, many candidate annotations could be inconsistent, or very unlikely, given the existing knowledge. A sound predictive framework capable of accounting for this type of constraints in making predictions could substantially contribute to the quality of machine-generated annotations at a genomic scale.ResultsWe present Ocelot, a predictive pipeline which simultaneously addresses functional and interaction annotation of all proteins of a given genome. The system combines sequence-based predictors for functional and protein-protein interaction (PPI) prediction with a consistency layer enforcing (soft) constraints as fuzzy logic rules. The enforced rules represent the available prior knowledge about the classification task, including taxonomic constraints over each GO hierarchy (e.g. a protein labeled with a GO term should also be labeled with all ancestor terms) as well as rules combining interaction and function prediction. An extensive experimental evaluation on the Yeast genome shows that the integration of prior knowledge via rules substantially improves the quality of the predictions. The system largely outperforms GoFDR, the only high-ranking system at the last CAFA challenge with a readily available implementation, when GoFDR is given access to intra-genome information only (as Ocelot), and has comparable or better results (depending on the hierarchy and performance measure) when GoFDR is allowed to use information from other genomes. Our system also compares favorably to recent methods based on deep learning
Pulmonary hypertension in sickle cell disease children under 10 years of age
No full textBr J Haematol. 2010 Sep;150(5):601-9. Epub 2010 Jun 10.
Pulmonary hypertension in sickle cell disease children under 10 years of age.
Colombatti R, Maschietto N, Varotto E, Grison A, Grazzina N, Meneghello L, Teso S, Carli M, Milanesi O, Sainati L.
Source
Department of Paediatrics, University of Padova, Padova, Italy. [email protected]
Abstract
Despite the finding of elevated Tricuspid Regurgitant Velocity (TRV) in children below 5 years of age, the prevalence and evolution of Pulmonary Hypertension (PH) in young children with sickle cell disease (SCD) are unclear. In order to identify predictive factors of precocious PH development, SCD children > or =3 years old, at steady state, underwent annual echocardiography and Tissue Doppler Imaging (TDI). Patients receiving chronic transfusion were excluded. Thirty-seven of seventy-five patients were > or =3 years, with measurable TRV. In our young population (mean age 6.2 years) of mainly African, HbS/HbS patients, 8/37 (21.6%) had TRV > or =2.5 m/s, 8% being only 3 years old. Significant correlation was found between precocious TRV elevation and high platelet and reticulocyte counts and frequent acute chest syndromes (ACS). In multivariate analysis, ACS was the only variable predicting TRV > or =2.5 m/s. TDI of the 37 patients showed signs of diastolic dysfunction of the left ventricle. At follow-up all eight patients with high TRV displayed further increase and seven more developed TRV > or =2.5 m/s. PH seems to begin in children earlier than expected. Factors involved in its early onset might be different from the ones causing its development in older children or adults. African children might benefit from early screening and re-assessment once a year.
PMID:
20553267
[PubMed - indexed for MEDLIN
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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