1,721,106 research outputs found
Evaluation of the lung in children with suspected pneumonia: usefulness of ultrasonography
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Role of connectivity topology in the transition between retrieving and non-retrieving phases in neural networks
No full textUltrasonographic study of Peyronie's disease
No full textInduratio penis plastica (IPP) is a degenerative disease, which consists in a thickening of the albuginea tunica of cavernous corpora, especially on the dorsal aspect. In 25% of the cases a calcified deposit is present. This disease can determine a bending of the penis, usually upward, pain during erection and impotentia coeundi. It is associated with Dupuytren's disease in 25% of the cases. IPP is of unknown etiological origin. The more reliable etiological theories are the degenerative one (micro trauma and inflammation) and the autoimmune one. The assessment of IPP is based on story, physical examination, autophotography (which are necessary) and on imaging techniques such as ultrasound, color Doppler, CT, MRI and X-ray in mammography. Color Doppler has demonstrated to be the best technique because of its cost/benefit and cost/effectiveness ratio. RMI with gadolinium can determine plaques activity but it has a lower cost/benefit ratio. Color Doppler can determine the presence of an IPP plaque and its status, which is size, location, and degree of calcification. Some authors sustain that inflammation can be suggested by the presence of micro vascularization around the plaque. US can be very useful to detect plaque in a size not easily accessible by physical examination (on the dorsal aspect of the penis) and to demonstrate plaques in different evolution moment. Ultrasonography is the better technique to show directly albuginea tunica. Authors illustrate the methodology, which use intra-cavernous injection of prostaglandin E1 (PGE1) to induce erection and its semeiotic findings
Critical behaviour of the stochastic Wilson-Cowan model
Full text linkSpontaneous brain activity is characterized by bursts and avalanche-like dynamics, with
scale-free features typical of critical behaviour. The stochastic version of the celebrated Wilson-
Cowan model has been widely studied as a system of spiking neurons reproducing
non-trivial features of the neural activity, from avalanche dynamics to oscillatory behaviours.
However, to what extent such phenomena are related to the presence of a genuine critical
point remains elusive. Here we address this central issue, providing analytical results in the
linear approximation and extensive numerical analysis. In particular, we present results supporting
the existence of a bona fide critical point, where a second-order-like phase transition
occurs, characterized by scale-free avalanche dynamics, scaling with the system size and a
diverging relaxation time-scale. Moreover, our study shows that the observed critical behaviour
falls within the universality class of the mean-field branching process, where the exponents
of the avalanche size and duration distributions are, respectively, 3/2 and 2. We also
provide an accurate analysis of the system behaviour as a function of the total number of
neurons, focusing on the time correlation functions of the firing rate in a wide range of the
parameter space
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
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