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Uncommon G9P[4] group A rotavirus strains causing dehydrating diarrhea in young children in Italy.
No full textGroup A rotaviruses (RVA) are one of the major cause of acute gastroenteritis (AGE) in young children, being responsible for up to 250.000 deaths worldwide, mostly in developing countries. The two outer capsid proteins VP7 (glycoprotein, G-genotype) and VP4 (protease-sensitive protein, P-genotype) are the basis for the binary RVA nomenclature. Although at least 36 G-types and 51 P-types of rotavirus are presently known, most RVA infections in humans, worldwide as well as in Italy, are related to six major G/P combinations: G1P[8], G2P[4], G3P[8], G4P[8], G9P[8] and G12P[8]. In November 2016, in the framework of the Italian 2016/17 rotavirus surveillance season, a total of 22 rotavirus-positive samples from hospitalized children presenting AGE symptoms were collected in a small area of Central Italy (Ancona, Marche). After genotyping, 3 samples presented the G9P[4] genotype. In order to better understand the origin of these uncommon RVA strains causing dehydrating diarrhea in three children, the strains RVA/Human-wt/ITA/AN18/2016/G9P[4], RVA/Human-wt/ITA/AN19/2016/G9P[4] and RVA/Human-wt/ITA/AN22/2016/G9P[4] were subjected to nucleotide sequencing of all the 11 gene segments to define their genomic constellation. Nucleotide sequencing revealed that the genomic constellation of the three strains was G9-P[4]-I2-R2-C2-M2-A2-N2-T2-E2-H2, highlighting human origin for all the gene segments investigated. The molecular characterization of RVAs and the continue monitoring of their circulation is needed to better define the epidemiology of these pathogen and to detect the emergence of viral variants presenting a high spreading potential in humans in the post-vaccination era
Molecular characterization of rotavirus strains from children with diarrehea in Italy, 2007-2009.
Get PDFThe surveillance network RotaNet-Italia was
established in 2007 in order to investigate
the diversity of co-circulating rotavirus strains
in Italy, and to provide a baseline for future
assessment of possible effects of vaccine
implementation in selecting novel versus
common rotavirus strains. A total of 2,645
rotavirus strains from pediatric patients with
acute diarrhea were collected over three consecutive
seasons from September 2006 through
August 2009, and partially characterized by
standardized multiplex RT-PCR. Most of strains
(89.1%) belonged to genotypes G1–G4, and G9,
associated with either P[8] or P[4], commonly
found in humans worldwide. However, in at
least 2.0% of cases, viruses exhibited either a G
or P type typical of animal viral strains, suggesting
gene reassortment events between
rotaviruses of different origin. Mixed infections
with two or more rotavirus strains were
observed frequently (7.6% of patients), and
depended on the frequencies of co-circulating
rotaviruses of one particular genotype. The
numbers and genotypes of likely natural reassortants
of common genotype rotaviruses were
found to be correlated with the observed numbers
and genotypes of mixed infections. Large
variation in the relative frequency of different
rotavirus genotypes was observed between different
seasons and/or areas of Italy, suggesting
independent evolution or differential introduction
of viral strains with respect to both time
and space
Molecular analysis of group A rotaviruses detected in adults and adolescents hospitalized with acute diarrhea in Italy in 2012.
No full textMolecular characterization of rotavirus strains from children with diarrhea in Italy, 2007-2009
No full textThe surveillance network RotaNet-Italia was established in 2007 in order to investigate the diversity of co-circulating rotavirus strains
in Italy, and to provide a baseline for future assessment of possible effects of vaccine implementation in selecting novel versus common rotavirus strains. A total of 2,645 rotavirus strains from pediatric patients with acute diarrhea were collected over three consecutive
seasons from September 2006 through August 2009, and partially characterized by standardized multiplex RT-PCR. Most of strains
(89.1%) belonged to genotypes G1–G4, and G9, associated with either P[8] or P[4], commonly found in humans worldwide. However, in at least 2.0% of cases, viruses exhibited either a G or P type typical of animal viral strains, suggesting gene reassortment events between rotaviruses of different origin. Mixed infections with two or more rotavirus strains were observed frequently (7.6% of patients), and depended on the frequencies of co-circulating rotaviruses of one particular genotype. The numbers and genotypes of likely natural reassortants of common genotype rotaviruses were found to be correlated with the observed numbers and genotypes of mixed infections. Large variation in the relative frequency of different
rotavirus genotypes was observed between different seasons and/or areas of Italy, suggesting independent evolution or differential introduction of viral strains with respect to both time and space
Evolution of human G4P[8] group A rotavirus strains circulating in Italy in 2013
No full textGroup A rotaviruses (RVA) are the leading cause of acute gastroenteritis in young (<5 years of age) children, causing up to 450.000 deaths worldwide, mostly in developing countries. VP7 (G-type) and VP4 (P-type) genotypes are the basis for the binary RVA classification. Although at least 27 G-types and 37 P-types of rotavirus are presently known, most RVA infections in humans worldwide are associated with the five major G/P combinations G1P[8], G2P[4], G3P[8], G4P[8] and G9P[8]. During RVA gastroenteritis surveillance in Italy, a total of 1112 samples collected from children hospitalized with acute gastroenteritis in 2013 were RVA positive and were genotyped following standardized protocols from the EuroRotaNet. Most strains analyzed belonged to the five major human genotypes. Among these common strains, 22 G4P[8] RVA strains from different Italian regions were subjected to nucleotide sequencing of their VP4, VP6, VP7 and NSP4 genes to investigate their evolution. The phylogenetic analysis showed that the Italian strains belonged to lineage G4-I for VP7 and to lineage P[8]-III for VP4, in line with the modern G4P[8] RVA strains detected in children worldwide. The phylogenetic trees revealed high degrees of nucleotide identity between the RVA strains involved in this study and G4P[8] strains detected previously in Europe, Asia and Africa, but also demonstrated at least three separate evolution clusters within the same lineage. Based on the amino acid sequences deduced for their hypervariable regions, both the VP7 and VP8* proteins of the Italian G4P[8] RVA strains presented amino acid substitutions near known neutralizing epitopes
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
Variations 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
Uncommon G9P[4] group A rotavirus strains causing dehydrating diarrhea in young children in Italy
Get PDFGroup A rotaviruses (RVA) are one of the major cause of acute gastroenteritis (AGE) in young children, being responsible for up to 250.000 deaths worldwide, mostly in developing countries. The two outer capsid proteins VP7 (glycoprotein, G-genotype) and VP4 (protease-sensitive protein, P-genotype) are the basis for the binary RVA nomenclature. Although at least 36 G-types and 51 P-types of rotavirus are presently known, most RVA infections in humans, worldwide as well as in Italy, are related to six major G/P combinations: G1P[8], G2P[4], G3P[8], G4P[8], G9P[8] and G12P[8]. In November 2016, in the framework of the Italian 2016/17 rotavirus surveillance season, a total of 22 rotavirus-positive samples from hospitalized children presenting AGE symptoms were collected in a small area of Central Italy (Ancona, Marche). After genotyping, 3 samples presented the G9P[4] genotype. In order to better understand the origin of these uncommon RVA strains causing dehydrating diarrhea in three children, the strains RVA/Human-wt/ITA/AN18/2016/G9P[4], RVA/Human-wt/ITA/AN19/2016/G9P[4] and RVA/Human-wt/ITA/AN22/2016/G9P[4] were subjected to nucleotide sequencing of all the 11 gene segments to define their genomic constellation. Nucleotide sequencing revealed that the genomic constellation of the three strains was G9-P[4]-I2-R2-C2-M2-A2-N2-T2-E2-H2, highlighting human origin for all the gene segments investigated.
The molecular characterization of RVAs and the continue monitoring of their circulation is needed to better define the epidemiology of these pathogen and to detect the emergence of viral variants presenting a high spreading potential in humans in the post-vaccination era
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
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