1,720,969 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
[MR-guided stereotactic breast biopsy: technical aspects and preliminary results]
No full textAIM:To assess the feasibility and accuracy of cytologic and microhistologic breast biopsy using a MR imaging-guided stereotactic system with MR-compatible non-magnetic needles.MATERIALS AND METHODS:Between December 2001 and September 2002, cytologic and microhistologic sampling of 14 lesions (12 patients) was performed in our radiology department using a commercially available MR-guided stereotactic device. MR-compatible non-magnetic needles or mixed kit (non-magnetic coaxial needle + conventional ferromagnetic needle) were used. Of the 12 patients examined, 2 were undergoing MR examination because of genetic/familial risk, 4 during post-operative follow-up and the remaining 6 for contradictory mammographic and sonographic findings. Ten of the 14 lesions were visible on MR alone. The mean lesion diameter was 12 mm (range 5-30 mm).RESULTS:The procedure was relatively simple and feasible. The procedure took 45 minutes on average. The cytologic samples were adequate in 4/14 cases (29%). The diagnosis was absence of malignant cells in one case, ductal carcinoma in one case and suspected carcinoma in two cases. The cytologic diagnosis was confirmed by core biopsy, and by post-operative histology in the malignant lesions. The remaining 10/14 (71%) cytologic samples were inadequate for diagnosis. All the microhistologic samples (100%) were considered sufficient for diagnosis and yielded diagnosis of benignity in 9/14 (60%) lesions and malignancy in 5/14 (40%). Two patients with benign diagnosis underwent surgery, which confirmed the diagnosis. The remaining seven patients were evaluated by follow-up MRI; the first follow-up at 3 months showed no significant changes. Post-operative histology of the 5 lesions with malignant microhistologic diagnosis confirmed the nature of the lesions.CONCLUSIONS:MR-guided stereotactic biopsy is a simple, fast and safe procedure comparable to the interventional breast procedures performed under mammography and ultrasound guidance. The stereotactic device used ensures correct positioning of the needle into the lesion. The new dedicated non-magnetic needles and the mixed kit provide quantitatively and qualitatively adequate tissue for the histologic analysis. On the basis of our initial experience, we conclude that the procedure is feasible and accurate and can therefore be recommended for routine clinical us
PERCUTANEOUS RETRIEVAL OF INTRAVACULAR FOREIGN BODIES AND REPOSITIONING OF MISPLACED CATHETERS: PERSONAL EXPERIENCE IN 48 CASES
No full textPOWER DOPPLER ULTRASOUND (PDU) AND MICROBUBBLE CONTRAST AGENT (MCA) IN DIFFERENTATION BETWEEN BINIGN AND MALIGNANT BREAST NODULES: SIGNIFICANCE OF MEAN RESISTIVE INDEX (MRI) AND ENHANCEMENT POST-MCA
No full textVariations 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
POWER DOPPLER ULTRASOUND (PDU) AND MICROBUBBLE CONTRAST AGENT (MCA) IN DIFFERENTATION BETWEEN BENIGN AND MALIGNANT BREAST NODULES: SIGNIFICANCE OF MEAN RESISTIVE INDEX (MRI) AND ENHANCEMENT POST-MCA
No full textENDOVASCULAR REPAIR WITH COVERED STENT OF SPLENIC ARTERY ANEURYSMS (SAA): TECHNICAL ASPECTS, SUCCESS RATE, COMPLICATIONS AND FOLLOW-UP AT TWO YEARS
No full textAppropriate 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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