1,720,985 research outputs found
Characterization of Thyroid Nodules by 3-D Contrast-Enhanced Ultrasound Imaging
No full textHigh resolution ultrasound imaging proved effective in the detection, analysis, and follow-up of thyroid lesions, even if interpretative pitfalls remain. Differentiation between malignant and benign nodules is a major challenge: malignancy is often correlated to an increase in intranodular vasculature, due to rapid angiogenesis
Skeletonization of 3-D contrast enhanced ultrasound images for the accurate characterization of thyroid nodules
No full text
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
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
Automated benign & malignant thyroid lesion characterization and classification in 3D contrast-enhanced ultrasound.
No full textIn this work, we present a Computer Aided Diagnosis (CAD) based technique for automatic classification of benign and malignant thyroid lesions in 3D contrast-enhanced ultrasound images. The images were obtained from 20 patients. Fine needle aspiration biopsy and histology confirmed malignancy. Discrete Wavelet Transform (DWT) and texture based features were extracted from the thyroid images. The resulting feature vectors were used to train and test three different classifiers: K-Nearest Neighbor (K-NN), Probabilistic Neural Network (PNN), and Decision Tree (DeTr) using tenfold cross validation technique. Our results show that combination of DWT and texture features in the K-NN classifier resulted in a classification accuracy of 98.9%, a sensitivity of 98%, and a specificity of 99.8%. Thus, the preliminary results of the proposed technique show that it could be adapted as an adjunct tool that can give valuable second opinions to the doctors regarding the nature of the thyroid nodule. The technique is cost-effective, non-invasive, fast, completely automated and gives more objective and reproducible results compared to manual analysis of the ultrasound images. We however intend to establish the clinical applicability of this technique by evaluating it with more data in the future
Bioconstrucciones coralinas de la formación agrio, Valanginiano-Hauteriviano de la Cuenca Neuquina: praderas de corales y arrecifes en parche
No full textEn la Formación Agrio de la Cuenca Neuquina (Valanginiano-Hauteriviano) los niveles dominados por corales escleractínidos aparecen a lo largo de toda la sucesión y en un conjunto amplio de localidades, desde el centro de Mendoza hasta el sur de Neuquén. La mayoría constituyen depósitos lenticulares a lentiformes de extensión lateral limitada a pocos cientos de metros en cada localidad, pero algunos de ellos pueden correlacionarse lateralmente entre distintas localidades, por lo cual pueden llegar a ser niveles coralinos de alcance regional (hasta unos 150 km en dirección N-S). Su espesor suele ser delgado, usualmente menor a 3 m, sin embargo algunos de los intervalos que contienen niveles coralinos pueden alcanzar 25-30 m de espesor. Sobre la base de trabajos de campo de detalle y levantamiento de secciones se han reconstruido dos tipos de bioconstrucciones coralinas: praderas de corales y arrecifes en parche. Las praderas estaban formadas por corales ramosos que podían alcanzar hasta 1 m de altura y tenían muy baja diversidad, ya que por lo general eran monogenéricas. Un ejemplo de este tipo de bioconstrucción fue registrado en la subzona de Olcostephanus (O.) laticosta, en la localidad de Loma Rayoso. Los arrecifes en parche eran más diversos que las praderas, incluyendo hasta ocho géneros distintos; estaban conformados por una fase de iniciación con corales planos y faceloides y una fase de diversificación con corales masivos, cónicos, ramosos y discoidales. Las colonias faceloides habrían alcanzado 30-40 cm de altura, las masivas podían medir hasta 50 cm de diámetro y 70 cm de altura, las ramosas podían alcanzar más de 1 m de altura y los discoidales no sobrepasaban los 10 cm de diámetro. Se han registrado arrecifes en parche en la zona de Paraspiticeras groeberi de la localidad de Agua de la Mula, y en la zona de Sabaudiella riverorum de la localidad de Bajada Vieja.Fil: Garberoglio, R. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Lazo, Dario Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaXII Congreso de la Asociación Paleontológica ArgentinaBuenos AiresArgentinaAsociación Paleontológica Argentin
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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