1,720,960 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
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
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
Permeation and Selective Retention of Solutes in PEGDA Hydrogel Membranes Containing Free Polymer Chains
No full textInternational audienceWe performed permeation experiments using PEGDA-based hydrogel membranes in which we added free polymer chains. We know from previous studies that free polymer chains can be trapped in the PEGDA matrix. Therefore, we use this property to trigger the retention of solutes through noncovalent interactions (heterogeneous bonds and electrostatic interactions) between the solute and the free polymer chains. We show that proton-donor molecules bearing carboxylic acid groups can be retained by hydrogen interactions at low pH with the free PEG (poly(ethylene glycol)) chains, which are proton acceptors. PEG is a nonionic hydrophilic polymer based on ethylene oxide units (−CH2CH2O−) which is a proton acceptor and can establish hydrogen bonds with proton-donor groups (such as COOH). The extent of retention increases with the number of acidic groups on the solute. By adding PAA (poly(acrylic acid), based on acrylic acid (−CH2CHCOOH), these groups are negatively charged at pH > pKa, i.e., pH > 5) in the PEGDA/PEG membranes, we show that positively charged molecules can be retained inside the membranes at a pH where the PAA is ionized. This retention is reversible, and solute molecules can be flushed out by reducing the pH below the pKa of PAA. By measuring the adsorption isotherm of molecules in the membranes, we obtain the interaction energy between the solute and PAA, which is consistent with electrostatic interactions. Finally, we photopolymerize our membranes directly in a microfluidic chip to perform tangential filtration of a mixture of fluorescein (negatively charged) and rhodamine B (zwitterionic). Fluorescein is repelled by negatively charged PAA and does not penetrate the membrane, while rhodamine B is retained and eventually permeates through. These findings pave the way to functionalization of hydrogel membranes by trapping free polymer chains for selective retention and filtration
The mechanical properties of lipid nanoparticles depend on the type of biomacromolecule they are loaded with
No full textInternational audienceFor drug delivery systems the mechanical properties of the drug carriers are suspected to play a crucial role in the delivery process. However there is a lack of reliable methods available to measure the mechanical properties of drug carriers which hampers the establishment of a link between delivery efficiency and mechanical parperties of carriers. Lipid nanoparticles (LNPs) are advanced systems for delivering nucleic acids to target cell populations for vaccination purposes (mRNA) or the development of new drugs. Hence it is crucial to develop reliable techniques to measure the mechanical properties of LNPs. In this article, we use AFM to image and probe the mechanical properties of LNP which are either loaded with two different biopolymers either pDNA or mRNA. Imaging the LNP before and after the indentation as well as recording the retraction curve enables us to obtain more insight on 1 how the AFM tip penetrates into the particle and to determine whether the deformation of the LNP is reversible. For pDNA, the indentation by the tip leads to the irreversible rupture of the LNPS while the deformation is reversible for the mRNA-loaded LNPs. Moreover, the forces reached for pDNA are higher than for mRNA. These results paves the way toward the establishment of the link between the LNP formulation and the delivery efficiency
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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