1,720,974 research outputs found

    Species identification in petfood by using BLAST analysis of a fragment of the mitochondrial 16s ribosomal RNA gene (16srRNA).

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    The aim of this work was to verify the label information of pet food for cats, reporting the commercial denomination of Bianchetto among the ingredients, by sequencing and BLAST analysis of a short fragment of the mitochondrial 16SrRNA gene. Fifteen samples of petfood for cats were collected from the retail market. Three fish per samples were analyzed. After DNA extraction, performed according to Armani et al. (2011) (1), the DNA degradation pattern was assessed by electrophoretic analysis. On the basis of the 108 sequences available in GenBank belonging to the order Clupeiformes and Osmeriformes, four different primers were designed and used in combination with those reported in Armani et al. (2012) (2), for the amplification of short fragments of the mitochondrial 16SrRNA gene with a length ranging from 77 to 246 pb. Such fragments were preventively tested by BLAST analysis (http://blast.ncbi.nlm.nih.gov/Blast.cgi?PROGRAM=blastn&BLAST_PROGRAMS=megaBlast&PAGE_TYPE=Bl astSearch&SHOW_DEFAULTS=on&LINK_LOC=blasthome) to assess their discriminatory power at inter and intra specific level. After PCR amplification, the samples associated to the expected amplicon were sequenced and the 45 sequences obtained were analyzed using the program Clustal W in Bioedit version 7.0.9.0 (3) and identified by BLAST analysis. The BLAST analysis returned an identity values of 100% with different species of the genus Encrasicholina. In particular, the most part of the samples were identified at the species level as E. heteroloba, and E. punctifer. The obtained results confirms that the molecular marker selected in this study can be used for the identification of species belonging to the Clupeiformes order, allowing a discrimination even among close species. All the 15 market pet food samples were mislabeled. In fact, while the species identification performed by molecular analysis clearly showed the presence of the juvenile form of Encrasicholina sp, also known as tropical anchovies, all the labels reported the commercial denomination of Bianchetto, which, in Italy, is allowed only for the juvenile form of Sardina pilchardus (4)

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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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