1,720,969 research outputs found
Genic targets used for the identification of periodontal pathogens by PCR base methods
No full textIn the course of time the laboratory diagnosis of periodontal infection has been influenced by the
difficulties encountered in the transport, growth and identification of the different pathogenic species involved
in periodontal disease: species that form a complex biofilm on the subgengival plaque and require
anaerobic conditions.
The traditional cultural diagnostic method has been replaced by molecular ones (PCR), a technique able to
identify the different species responsible for periodontal disease and which, in its real time PCR version, is also
able to quantify the different bacteria species present in a sample.
The core of the “PCR based method” procedure is represented by the in silico diagnostic system that includes:
(i) a genetic target, representative of the single bacteria species under examination, (ii) oligonucleotides
(primers and/or fluorescent probes) with optimal thermodynamic characteristics.
Nevertheless, even though the methods available in the literature and from commercial kits provide procedures
that are considered specific, sensitive and fast, they do not take into consideration the most important
parameter of polymicrobial infection analysis: namely selectivity.
The selectivity of a diagnostic test is represented not only by its ability to reveal low titles of a single pathogen
species compared to high titles of other ones, but also by its capacity to point out simultaneously and with the
same level of accuracy, the presence and/or the concentration of different microbial species.
The purpose of this work is the description of the current sequences of nine different primary periodontal
pathogens deposited in DNA Data Banks: Tannerella forsythensis, Porphyromonas gingivalis, Treponema
denticola, Prevotella intermedia, Fusobacterium nucleatum ssp, Camphylobacter gracilis, Prevotella nigriscens,
Eichenella corrodens, Aggregatibacter actinomycetemcomitans and subsequently the in silico evaluation
of the DNA regions characterized by a good selectivity
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
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
Interaction of the thyrotropin receptor on rat FRTL-5 thyroid cells with thyrotropin and a thyrotropin-stimulating autoantibody from Graves' patients
No full textFRTL-5 rat thyroid cells were either surface-labeled with 125I or biosynthetically labeled with [3H]N-acetylglucosamine, solubilized by lithium diiodosalicylate and immunoprecipitated after sequential exposure to bovine thyrotropin and anti-bovine thyrotropin. Autoradiography of polyacrylamide gels run under denaturing conditions and in the presence of a reducing agent revealed two prominent bands with approximate molecular weights of 66-70 kDa and 47 kDa. Immunoprecipitation of the same radiolabeled and solubilized membrane preparations with a Graves' disease IgG having thyroid stimulating but no thyrotropin-binding inhibiting activity revealed only one major band, migrating near the 47 kDa component reactive with thyrotropin. No bands were immunoprecipitated in control incubations using normal human IgG or substituting radiolabeled, solubilized membranes from a rat thyroid cell line with no thyrotropin receptor activity. Thin layer chromatography of Folch extracts of the [3H]-N-acetylglucosamine-labeled immunoprecipitates obtained by either procedure indicated that a specific thyroid ganglioside was coprecipitated with the immunoprecipitated proteins in both cases
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