1,720,957 research outputs found
Studio genetico della provincia di Piacenza attraverso l’analisi dei polimorfismi della regione HLA
No full textA fast amplification-reverse hybridization assay kit to detect the most frequent deficient variants in the alpha-1-antitrypsin gene.
No full textThere is worldwide growing awareness of alpha-1-antitrypsin deficiency (AATD), a major hereditary disorder in Caucasians. The gold standard for its laboratory diagnosis is thin-layer isoelectric focusing, which should be performed in reference laboratories.The aim of this study was to check the characteristics of a commercially available amplification-reverse hybridization assay kit in detecting at a molecular level the alpha-1-antitrypsin (AAT) Z and S variants, i.e. the most frequent variants associated with AATD, by comparing its performance with DNA restriction fragment length polymorphism.We studied samples from 36 subjects enrolled in the Italian National Registry for Severe Alpha-1-antitrypsin Deficiency. Based on previous plasma isoelectric focusing typing, we selected samples with the following phenotypes: MM (9 samples), MS (9 samples), SZ (3 samples), MZ (11 samples), ZZ (3 samples), and a rare variant (1 sample). DNA was extracted by the standard method. The presence of the AAT Z and S gene variants was determined by the amplification-reverse hybridization test kit, following the manufacturer's instructions, and by the restriction fragment length polymorphism technique, according to established procedures.We found that the identification of the AAT Z and S gene variants obtained by the amplification-reverse hybridization test kit was completely in agreement with that obtained by the restriction fragment length polymorphism technique.We conclude that the test kit provides a fast, easy and unambiguous identification of Z and S alleles. Because of its transferability to routine laboratories, the test kit may be useful in identifying cases of severe AATD, thus resulting in increasing awareness of this rare disorder
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Genetic study in Northern Italy and comparison with Western European populations
No full textThe genetic structure of the province of Piacenza, in Northern Italy, was studied with the aim of finding genetic traces of ancient populations. MHC genes and STR microsatellites of inhabitants with grandparents of the same area were analysed. Our results show that the population of the mountainous region of the province of Piacenza has more genetic similarities with Basques than with other european populations
Variations on the Author
Full text link“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
Full text linkWe 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
Full text linkWe 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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