1,721,008 research outputs found
Inventory of the Vatican meteorite Collection,
No full textThe Vatican Meteorite Collection is a valuable research resource that is housed in Castel Gandolfo in the care of the Vatican Observatory (Specola Vaticana). The vast majority of specimens in the collection were donated to the Vatican by Adrian-Charles, Marquis de Mauroy, but additional specimens have been acquired through exchanges and other gifts. The purpose of the inventory is to verify and enumerate the meteorite specimens presently stored in the Vatican Meteorite Collection. Specimens were listed by the names used in the British Museum catalogs
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
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
Usefulness of dual-time point imaging after carbonated water for the fluorodeoxyglucose positron emission imaging of peritoneal carcinomatosis in colon cancer
No full textBACKGROUND: Fluorodeoxygluose (FDG) positron emission/computed tomography (PET/CT) is emerging as a useful tool for the diagnosis of peritoneal carcinomatosis (PC). In this study, we assessed whether dual-time point imaging can improve the accuracy of FDG PET/CT for the diagnosis of PC after colon rectal cancer (CRC).
METHODS: Thirty-nine patients with past history of CRC were evaluated. Whole-Body PET/CT scan was acquired 1 hour after tracer injection. If one or more focal areas of increased FDG uptake (standardized uptake value, SUV max>2.5) were found in the abdomen, 1 L of carbonated water was orally administered to patients and a delayed scan of the abdominal region was acquired at 2 hours. The SUV max and the mean Delta (Δ) SUV were calculated. The scintigraphic results were compared with the results of colonoscopy and histology and with the clinical follow-up.
RESULTS: Thirteen out of the 39 patients did not show any significant area of FDG uptake at the whole-body scan. The remaining 26 patients showed an overall number of 27 sites of focal increased uptake, showing a mean SUV max of 6.5+3.3. Late scan of the abdomen showed vanishing spots in 11 cases. Focal and increasing FDG uptake was found in 15 subjects (for an overall number of 16 sites) with SUV max of 15.6+4 and mean Δ SUV of +26.3%±7.5%. In these cases, final diagnosis was PC in 10 patients (according to cytology or histology) and dysplastic polyp in 5 cases. No significant difference in Δ SUV was found between patients with PC and those with polypoid formations.
CONCLUSIONS: According to our results, dual-time point imaging after carbonated water may increase the accuracy of FDG PET/CT for the imaging of PC in patients affected by CRC
Mediterranean vegetation analysis by multi-temporal satellite sensor data
No full textA mediterranean vegetated coastal area has been classified on the basis of multi-temporal TM images and accurate field data. The latter was revealed to be particularly important due to the complexity of the area in terms of coverage degree, height structure of living vegetation and the occurrence of under-storey species. The recognition and classification of the different coenosis has taken into account that the spectral characteristics of vegetation depends on the season and on local climatic conditions. A major improvement in the spatial resolution of spectral data has been obtained by merging TM and SPOT-P by a RGB-IHS transformation that allowed an overall accuracy in the classification of 85 per cent to be achieved
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