1,720,985 research outputs found
Epileptic seizures can be anticipated by geometric-topological entropy analysis
Full text linkEpilepsy is a complex brain disorder characterized by an hypersynchronous activity of neural ensemble in the brain. Nowadays electroencephalography (EEG) is the golden stan- dard for studying, monitoring and diagnosing epilepsy. Signals (time series), recorded by EEG, represent a description of the dynamics of the brain. Epilepsy is an emergent behavior given by a phase transition between a non-epileptic state (pre-ictal state) and an epileptic one (ictal state) of the neural hypergraph [1-2]. Traditional linear techniques applied to EEG show some limitation to identify these transitions while the non-linear ones seem to be more promising. The understanding of the underlying mechanisms of ictogenesis and propagation requires a suitable formal method to compute the model that supports the anticipation of ictal states. Recently, Topological Data Analysis and topological entropy [3-4], the so-called persistent entropy, are proven to be encouraging for distinguishing healthy from unhealthy patients by showing numerical evidence of the occurrence of phase transitions. We extend the previous work by providing a theoretical justification, based on statistical indexes (skewness and kurtosis), persistent entropy and topological invariants (Betti numbers), of the preliminary numerical results which describe the occurrence of a phase transition; moreover, we also intend to investigate the role of geometric entropy in quantifying the complexity of the networks since a change of complexity is also an indicator of a phase transition [5].
References
1. Varela F.J.; Naturalizing Phenomenology: Issues in Contemporary Phenomenology and Cognitive Science Edited by Jean, Petitot, Francisco J. Varela, Bernard Pachoud abd Jean-Michel Roy Stanford University Press, Stanford Chapter 9, pp.266-329
2. Piangerelli M.; Merelli E.; RNN-based Model for Self-adaptive Systems - The Emer- gence of Epilepsy in the Human Brain. IJCCI (NCTA).2014: 356-361
3. Merelli E.; Piangerelli M.; Rucco M.; Toller D.; A topological approach for multivariate time series characterization: the epileptic brain.2015
4. Rucco M.; Castiglione F.; Merelli E.; Pettini M.; Characterization of idiotypic immune network through Persistent Entropy. In Proc. Complex2015
5. Franzosi R.; Felice D.; Mancini M.; Pettini M.; A geometric entropy detecting the Erdös-Rényi phase transition. EPL.201
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
Red LED light in skin regeneration: an in vitro study on human dermal fibroblasts
No full textThe use of noncoherent light (light-emitting diodes, LEDs), in particular the Red LED light, represents an innovative approach to tissue regeneration. In dermatological field, experimental studies on its regenerative effect started about ten years ago but the exact mechanism of its action should be better elucidated. Today, a new treatment, named “Dermodinamica” (Elisor, Milan), uses this approach with a wavelength of 630nm to promote skin regeneration. Dermal fibroblast is a primary cell type responsible for synthesis and remodeling of extracellular matrix in human skin. Several studies have reported cytokine-dependent changes in extracellular matrix composition and in particular transforming growth factor (TGF)-beta1 is a fibroblast stimulating cytokine effective on both type I collagen and hyaluronan production. Moreover, ROS-detoxifying enzymes, such as superoxide dismutases (SOD) and heme-oxygenase 1 (HO-1), have an important role in cutaneous wound repair. The aim of the present in vitro preliminary study was to evaluate the effect of Red LED light (Dermodinamica, Elisor, Milan) on normal human dermal fibroblast (NHDF) at 24h from exposition monitoring: cell viability using MTT assay; TGF-beta1 production using ELISA kit; expression of SOD-1 and HO-1 using immunohistochemical technique. Moreover, short (15 min exposition) and prolonged (30 min exposition) treatments were investigated. The results showed a progressive increase in TGF-beta1 release respectively in the short treatment (15 min exposition) and in the prolonged treatment (30 min exposition). Moreover, the ROS-detoxifying enzymes were modulated by this treatment and the cell viability was maintained. These data support the hypothesis of the positive influence of Red LED light in the biological processes involved in skin regeneration
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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