1,721,837 research outputs found
Gli angiomi del distretto maxillo-facciale: ruolo della scintigrafia con emazie marcate.
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80. Carpanese L, Pizzi G, Golfieri R, Fiore F, Gasparini D (2006). A Phase II Clinical trial on hepatic intra-arterial injection of Yttrium-90 Microspheres in unresectable colorectal liver metastases refractory to standard i.v. chemotherapy. Preliminary results. Abstract First World Conference on Interventional Oncology (WCIO). Cernobbio, June 12-16, 2006
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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
AGN Feedback: Radio-Loudness Distribution and the Kinetic Luminosity function
No full textWe have studied the AGN radio emission from the largest existing compilation of hard X-ray selected samples, all observed in the 1.4 GHz band. A total of more than 1600 AGN have been used. For the first time, it was possible to almost completely measure the probability distribution function of the ratio between the radio and the X-ray luminosity RX , which has been function-ally fitted as dependent from the X-ray luminosity and redshift. These measures have allowed us to estimate the AGN kinetic luminosity function and its evo-lution. It results that, in agreement with previous estimates, the efficiency kin in converting the accreted mass energy into kinetic power (LK = kin mc2 ) is on average kin ̃5 × 10-3 . ̇ The derived value and evolution of the kinetic energy density is in qualitative agreement with some of the last generation galaxy evolution models, where radio mode AGN feedback is invoked to quench the star formation in galaxies and slow down the cooling flows in galaxy clusters
Testing the ionized disc reprocessing model for the soft X-ray emission of quasars
No full textOne of the current explanations for the soft X-ray emission of active galactic nuclei (AGN) is reprocessing of the hard X-rays by partially ionized, optically thick matter. This idea is very appearing because it would explain the shape of the AGN soft X-ray spectrum in terms of atomic physics. While at present the reflection model correctly describes the soft X-ray spectra of a few low-luminosity Seyfert galaxies, it is not clear whether or not it can be applied to higher luminosity quasars. To investigate this issue quantitatively, we have fitted the high signal-to-noise ratio Position Sensitive Proportional Counter (PSPC) spectra of 11 AGN of different luminosities with a model consisting of a direct hard X-ray component, reflection from the ionized surface of an accretion disc and the direct thermal emission of the disc. We find that the AGN with an acceptable fit are a minority, and all have a low optical (and bolometric) luminosity, flat PSPC energy index alpha(PSPC) and the flattest alpha(OX) of the sample, while those with the worst fit all have high optical (and bolometric) luminosity, steep alpha(PSPC) and the steepest alpha(OX) of the sample. We conclude that either the reprocessing model is not correct and the form of the soft X-ray spectrum of AGN cannot be simply explained in terms of characteristic atomic features (i.e. highly ionized oxygen K-edges), or the origin of the soft X-ray emission of AGN is not 'universal'
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