1,721,091 research outputs found
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
An extensive multi-approaches distribution map of Apis mellifera mitochondrial DNA lineages in Italy
No full textThe conservation of the genetic integrity of honey bee subspecies is a matter of concern in Europe. Specific mitochondrial DNA (mtDNA) lineages characterize several Apis mellifera subspecies. In this study we produced a distribution map of the main A. mellifera mtDNA lineages in Italy by combining two approaches: (1) mtDNA analyses of individual honey bees; (2) mtDNA analyses from honey environmental DNA. This second approach was also applied to obtain a distribution map of mtDNA lineages over four years in the North of Italy. DNA was extracted from ~800 worker bees collected in 2020 and 730 pupae collected in 2021 from different colonies. DNA was also extracted from about 1,600 honey samples produced in the North of Italy over four years (2018-2021) and additional 400 honey samples produced in 2018 in the Central and South of Italy and in the two main Italian islands (Sardinia and Sicily). PCR amplified fragments were sequenced or separated using a size-based assay. Both approaches showed that the C lineages were the most frequent mitotypes all over Italy except in Sicily, where the A lineage was highly represented. Individual bee analyses showed that the C1 mitotype, which mainly characterizes the A. m. ligustica subspecies, was the most frequent mtDNA haplotype in the investigated cohorts. Nevertheless, mtDNA haplotypes associated with non-endemic subspecies (A and M lineages) were present in almost all Italian regions and constantly represented over years. The obtained information can be useful to design conservation strategies of A. mellifera genetic resources in Italy
A comprehensive overview of mitochondrial DNA insertions in the nuclear genome of the pig
No full textThe integration of nuclear mitochondrial DNA into the mammalian genomes is an ongoing but
rare evolutionary process that produces nuclear sequences of mitochondrial origin (NUMTs).
In this study we identified and analysed NUMTs of the porcine genome. We first constructed a
comparative distribution map of NUMTs in the Sscrofa11.1 reference genome and in other 14
assembled and drafted pig genomes (of Asian and European origin). Then, a total of 581 whole
genome sequencing datasets, from 35 different breeds or populations, were analysed for the
discovery of recently integrated and polymorphic NUMT positions. Overall, we built a comprehensive catalogue of more than 500 NUMTs, some of which were not included in the assemble genomes. Breed-specific NUMTs as well as segregating NUMTs were also identified.
This work lays the base for in-depth studies on the phylogeny of Sus scrofa populations
An over-time distribution map of the main Apis mellifera mitochondrial DNA lineage using honey as source of eDNA.
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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