1,721,002 research outputs found
Biologia dello sviluppo - 1. Gametogenesi
No full textSono descritti i tratti fondamentali della biologia dello sviluppo. Nel primo capitolo il centro dell’attenzione è focalizzato sul controllo del ciclo cellulare, in particolare della meiosi. Nel secondo capitolo viene dato rilievo ai meccanismi funzionali dei processi di proliferazione, differenziamento, maturazione e trasporto dei gameti maschili degli animali, con particolare riferimento alla specie umana. Nel terzo capitolo vengono invece trattati gli argomenti fondamentali riguardanti la ovogenesi
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
Identification of gadoid species (Pisces, Gadidae) by sequencing and PCR-RFLP analysis of mitochondrial 12S and 16S rRNA gene fragments.
No full textWe applied PCR–RFLP (PolymeraseChainReaction – Restriction Fragment Length Polymorphism) analysis to identify seven gadoid species of different biogeographical origin and commercial relevance, namely Gadus morhua (Atlantic ocean); Trisopterus minutus capelanus, Trisopterus minutus minutus, Molva elongata, Phycis blennoides, Micromesistius poutassou (Atlantic ocean and Mediterranean sea); Theragra chalcogramma (Pacific ocean). Two DNA fragments belonging to mitochondrial 12S and 16S rRNA genes of about 430 and 630 bp, respectively, were isolated by PCR amplification. Their direct sequencing showed a significant genotypic diversity among gadoid species, useful for species identification. Digestion of 16S rRNA gene PCR fragment with MvaI or Bsh1285I restriction enzymes, followed by agarose gel electrophoresis of the cleaved products, yielded specific restriction profiles that enabled direct, visual identification of the species analyzed. This PCR– RFLP method allowed a clear and rapid discrimination of the gadoid species studied
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
Enzymatic evaluation of fish selenoproteins: glutathione peroxidase (GPx) and phospholipid hydroperoxide glutathione peroxidase (PhGPx).
No full textAppropriate 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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