1,721,050 research outputs found
Zoonotic aspects of rotaviruses
No full textRotaviruses are important enteric pathogens of humans and animals. Group A rotaviruses (GARVs) account for up to 1 million children deaths each year, chiefly in developing countries and human vaccines are now available in many countries. Rotavirus-associated
enteritis is a major problem in livestock animals, notably in young calves and piglets. Early
in the epidemiological GARV studies in humans, either sporadic cases or epidemics by
atypical, animal-like GARV strains were described. Complete genome sequencing of
human and animal GARV strains has revealed a striking genetic heterogeneity in the 11
double stranded RNA segments across different rotavirus strains and has provided
evidence for frequent intersections between the evolution of human and animal
rotaviruses, as a result of multiple, repeated events of interspecies transmission and
subsequent adaptation
Genomic evolution, host-species barrier, reassortment and classification of rotaviruses
No full textRotaviruses are members of the Reoviridae family, causing severe diarrheal illness and death in humans and animals. They have been subdivided into at least seven serological groups (A-G), and, recently, a new rotavirus known as 'new adult diarrhea virus or ADRV-N was discovered. Only in group A rotaviruses have a substantial number of strains been analyzed completely on the molecular level. For groups B, C and ADRV-N rotaviruses a very limited number of complete genomes are available, and for group D, E and F no sequence data are available at all. Here, Yamamoto and colleagues describe the full genomic characterization of four human group B rotaviruses isolated in India, Bangladesh and Myanmar. These four strains were analyzed phylogenetically and individual gene segments were compared with their group A and C counterparts, indicating that functionally important motifs and structural characteristics were conserved. This study, together with others, highlights the need for complete genome analysis of rotaviruses, in order to study their genetic evolution, the occurrence of reassortments, crossing of the host-species barrier and their classification. Upcoming new mass sequencing technologies are expected to speed up the process of filling in the gaps in our data
Global distribution of group A rotavirus strains in horses : A systematic review
No full textGroup A rotavirus (RVA) is a major cause of diarrhea and diarrhea-related mortality in foals in parts of the
world. In addition to careful horse farm management, vaccination is the only known alternative to reduce
the RVA associated disease burden on horse farms. The precise evaluation of vaccine effectiveness against
circulating strains needs enhanced surveillance of equine RVAs in areas where vaccine is already available
or vaccine introduction is anticipated. Therefore, we undertook the overview of relevant information on
epidemiology of equine RVA strains through systematic search of public literature databases. Our findings
indicated that over 99% of equine RVA strains characterized during the past three decades belonged to
two common genotypes, G3P[12] and G14P[12], whereas most of the minority equine RVA strains were
probably introduced from a heterologous host by interspecies transmission. These baseline data on RVA
strains in horses shall contribute to a better understanding of the spatiotemporal dynamics of strain
prevalence in vaccinated and non-vaccinated herds
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Aspetto zoonosico dei rotavirus di gruppo A: un rotavirus di coniglio è patogeno nell’uomo
No full textVariations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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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