1,721,368 research outputs found
Parole Jelinek: Potere
No full textSul concetto di "potere" nell'opera teatrale di Elfriede Jelinek, premio Nobel 2004
Rethinking chromatin accessibility: from compaction to dynamic interactions
Full text link: The genome is traditionally divided into condensed heterochromatin and open euchromatin. However, recent findings challenge this binary classification and the notion that chromatin condensation solely governs the accessibility of transcription factors (TFs) and, consequently, gene expression. Instead, chromatin accessibility is emerging as a factor-specific property that is influenced by multiple determinants. These include the mobility of the chromatin fiber, the capacity of TFs to engage repeatedly with it through multivalent interactions, and the four-dimensional organization of its surrounding diffusible space. Unraveling the molecular and biophysical principles that render a genomic target truly accessible remains a significant challenge, but innovative methods for locally perturbing chromatin, coupled with microscopy techniques that offer single-molecule sensitivity, provide an exciting experimental playground to test new hypotheses
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
Diffusion-weighted MRI in cervical lymph nodes: Differentiation between benign and malignant lesions
No full textEur J Radiol. 2011 Feb;77(2):281-6. Epub 2009 Aug 28. Diffusion-weighted MRI in cervical lymph nodes: differentiation between benign and malignant lesions. Perrone A, Guerrisi P, Izzo L, D'Angeli I, Sassi S, Mele LL, Marini M, Mazza D, Marini M. Source Department of Radiological Sciences, Sapienza University, Policlinico Umberto I, Rome, Italy. Abstract OBJECTIVE: Purpose of our study was to assess the potential role of diffusion-weighted imaging (DWI) in the differential diagnosis between benign and malignant nodes. SUBJECT AND METHODS: We enrolled 32 subjects: 14 with benign lymphadenopathy, 17 patients with histologically proved malignant disease before beginning treatment and 1 patient with lymphoma after chemotherapeutic treatment. In all patients we used fast spin echo T2-weighted images in axial and coronal planes, fast spin echo T1-weighted images before and after contrast medium of administration in axial and coronal planes. Before contrast administration diffusion sequences were acquired on the axial and coronal plane (b factor of 0.500 and 1000 s/mm(2)) and then apparent diffusion coefficient (ADC) maps were reconstructed. RESULTS: On diffusion images, 13/14 patients with benign nodes showed low signal intensity and had high signal on ADC maps, whereas all patients with malignant diseases appeared hyperintense on diffusion images and with low signal intensity on ADC maps. Only a patient with tuberculosis showed a low ADC value. The mean ADC value of malignant nodes was about 0.85 × 10(-3)mm(2)/s, the mean value of benign nodes was 1.448 × 10(-3)mm(2)/s; this difference was statistically significant (p < 0.01). The mean ADC value of treated nodes was 1.75 × 10(-3)mm(2)/s. The best threshold value was 1.03 × 10(-3)mm(2)/s, obtaining a sensitivity of 100% and a specificity of 92.9%. CONCLUSIONS: Diffusion imaging could be considered an important supportive tool for the diagnosis of enlarged cervical lymphadenopathies. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved. PMID: 19716671 [PubMed - indexed for MEDLINE
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
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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