1,721,658 research outputs found
Pierluigi Pellini, Stefano Lazzarin (a cura di), Un “osservatore e testimone attento”. L’opera di Remo Ceserani nel suo tempo
No full textRecensione a Pierluigi Pellini, Stefano Lazzarin (a cura di), Un “osservatore e testimone attento”. L’opera di Remo Ceserani nel suo temp
Human immunodeficiency virus type 1 fitness and tropism: concept, quantification, and clinical relevance
No full textAbstractTwo distinct aspects of human immunodeficiency virus type 1 (HIV-1) biopathology with important implications for the management of treated patients have emerged during the last decade: changes in relative viral fitness, and viral tropism. First, it has been observed that HIV-1 accumulates deleterious mutations leading to drug resistance and different degrees of reduction in relative fitness during antiretroviral therapy (ART). Although the latter normally parallel a failure of ART resulting from selection of resistant mutants, the drop in viral replication capacity may be beneficial for the host. Moreover, specific antiviral compounds aimed at reducing viral fitness could be developed. Analysis of the determinants of viral fitness in highly evolving viral populations has shown that viral extinction may also be obtained by forcing highly dynamic viral populations through increased (lethal) mutagenesis that abolishes viral replication (violation of the error threshold). It could be of great interest in the near future to address this point with strategies specifically planned at the molecular level. Furthermore, diagnostic evaluation limited to the master sequence has low predictive value in rapidly evolving viral populations. These observations, together with the evidence that all of the methodologies currently used for fitness analysis have important limitations, strongly suggest that further research is warranted. This should use highly sensitive and flexible technologies to evaluate viral fitness directly in vivo or ex vivo, not only for the dominant mutants, but also for minority variants. Second, discovery of the two main co-receptors for HIV-1, CCR5 and CXCR4, has led to a better understanding of the interaction of the viral envelope with host cells and to the development of novel therapeutic agents that inhibit viral entry. In this perspective, analysis of HIV-1 tropism has acquired a major diagnostic role
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
HEFFICON: HIV Effectiveness Italian Conference
No full textSince the first acquired immunodeficiency syndrome cases were reported in 1981, more than 1.5 million people have been diagnosed with Human Immunodeficiency Virus-1 in Europe, including more than 136,000 new HIV cases in 2013. Recent epidemiological data estimate an incidence of 5-10 newly diagnosed HIV infections per 100,000 population per year in Europe and an average prevalence of infection of 5.7 cases per 100,000 population. In the absence of an effective curative strategy for HIV, optimization of prevention policies and clinical management of HIV positive patients is fundamental to reduce the impact of the HIV pandemic on public health. Clinical trials represent an essential tool for translating research findings into routine clinical practice. Careful evaluation and planning of clinical trials are therefore mandatory in order to provide relevant information to clinicians. The HEFFICON Project was conceived to investigate and pinpoint methodological issues and critical points that need to be addressed in future clinical studies to increase the translation of experimental results to the real life environment
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
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