1,720,996 research outputs found
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
Modello stocastico e validazione sperimentale di un metodo efficiente di trasduzione virale in microfluidica a basse dosi
No full textVariations 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
Isolamento primario di anticorpi monoclonali con membrane di affinità
No full textAffinity membrane chromatography is one of the processes considered as an alternative to conventional Protein A bead-based chromatography for the primary capture step of a monoclonal antibody production process.
In this work, new affinity membranes endowed with a very interesting binding capacity for human IgG have been experimentally characterized. The membranes have been extensively tested in dynamic experiments with pure IgG solutions and with a cell culture supernatant containing IgG1. The effects of flow rate and IgG concentration in the feed on the separation performances like binding capacity, selectivity and process yield have been studied in detail.
The comparison of the results obtained with literature data available for Protein A bead-based chromatography shows that the two processes have similar performance and these membranes can be used to overcome the throughput limitations and other well known drawbacks of traditional bead-based chromatographic columns
Modellazione della separazione di immunoglobulina G mediante membrane di affinità
No full textBead based chromatography is actually one of the main unit operation in the biotechnology industry. Nevertheless, several limitations are associated to this technique such as high pressure drops and slow mass transfer. Membrane based chromatography is one of the alternatives that are receiving increasing attention.
This work is focused on the purification of Immunoglobulin G via affinity membranes. Principally it is presented a mathematical model that accurately describes the protein separation process. The model proposed takes into account a mass balance over the porous medium and a kinetic equation to describe the interaction between the protein and the ligand immobilized onto the membrane.
Model validation has been performed over a wide range of experimental data obtained at different operating conditions. The model has been preliminary tested with chromatographic cycles performed with pure IgG; afterward, the model has been successfully used to describe the experimental data obtained with a complex feedstock
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