1,720,959 research outputs found

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

    Design and development of molecularly imprinted polymers and imprinted sensors

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    Esta tesis se ha hecho principalmente para estudiar e investigar polímeros impresos (MIPs) con la intención de usarlos como sensores de larga vida. La línea de investigación de esta tesis es la dirigida a conseguir la integración de estas formaciones impresas dentro de una lengua electrónica (ET), que es la rama de especialización en la que se ha desarrollado principalmente este proyecto. Después de hacer una revisión de la literatura, que inicialmente se centraba en la aplicación de MIPs a un equipo electroquímico, un sensor voltamétrico impreso y un procedimiento sensitivo complementario, el procedimiento se creó a través de una combinación de protocolos tomados de la literatura. Este sensor, descrito en el Artículo 1, presentaba una buena selectividad hacia el analito primario, teofilina, además de la especificidad requerida frente a sus análogos estructurales. Aunque el diseño del sensor permitía una mejor regeneración de la superficie respecto a otros sistemas parecidos encontrados en la literatura, el comportamiento de los polímeros usados en el MIP retardaba la tasa de transferencia de electrones en la superficie del sensor. Por culpa de este fenómeno, la sensibilidad del sensor se reducía. Justo después de estos experimentos iniciales, se hizo una colaboración con el grupo del Profesor Sergey Piletskey en la Universidad de Leicester (UoL) de Reino Unido. Durante este período, se realizó un estudio intensivo del proceso de diseño de impresión molecular asistido por un sistema computacional de modelización molecular ‘inhouse’. Se puso énfasis en el diseño de un receptor impreso para la molécula de baja solubilidad melanina, que se toma como ‘template modelo’. El MIP resultante se caracterizó y usó para la detección de melanina en muestras de leche, tal y como se describe y detalla en el Artículo 2. Más tarde, utilizando los conocimientos adquirido durante la estancia en Leicester, se desarrollaron nuevas técnicas de modelización computacional para la evaluación de los métodos utilizados en la modelización de MIPs, con el objetivo de obtener una técnica de evaluación virtual para el diseño de receptores impresos, optimizados para los requerimientos necesarios para su posterior aplicación en un sensor ET, tal como se detalla en el Artículo 3. Tal y como se detalla en el capítulo final de esta tesis, la experiencia y conocimientos adquiridos durante la investigación, se usaron para diseñar un grupo de sensores que funcionan asociados a ET. Este desarrollo podría ampliarse profundizando en la selección computacional de polielectrolitos, que luego serían inmovilizados en la superficie de un electrodo voltamétrico mediante una tinta de grafito conductora, de elevada robustez y estabilidad. En este sentido, también se proponen otras recomendaciones para lograr la mejora de la capacidad de regeneración de los MIPs utilizados, por ejemplo mediante la separación de MIP y electrodo. Finalmente, se presentan algunas sugerencias para colaboraciones institucionales, con el propósito de crear un sistema ET móvil, que permita recoger y analizar muestras en campo.This thesis was predominantly undertaken to study and investigate molecular imprinted polymers (MIPs) with a view to their use as high longevity sensing elements in sensor arrays. The research line of the thesis was intended to lead to the integration of these imprinted arrays into an Electronic Tongue (ET) sensing system which is the area of expertise of the research group in which this project was primarily executed. Having initially executed a review of the literature, focusing initially on the application of the MIPs to an electrochemical device, an imprinted voltammetric sensor and a complimentary sensing procedure was developed using a combination of protocols extracted from the literature. This sensor, described in Article 1, had good selectivity toward the primary analyte, theophylline, and specificity against structural analogues. Though the design of the sensor allowed for significantly improved regeneratibility of the sensor relative to similar systems in the literature, the insulating nature of the polymers used in the MIP reduced the electron transfer rate at the sensor surface and thus resulted in a reduction in sensitivity. Following this initial experimental study, a secondment was undertaken in the University of Leicester under the supervision of Professor Sergey Piletsky. During this period, an intensive study of the design process of molecular imprinting, aided by an in-house computational molecular modelling platform, was conducted focusing on the design of an imprinted receptor for the low solubility 'model template', melamine. This MIP was successfully synthesised, characterised and used in the detection of melamine in milk samples, as detailed in Article 2. Further development of computational modelling techniques for the evaluation of MIP modelling techniques was also achieved with a view to create a virtual evaluation technique for the design of imprinted receptor sites optimised for the requirements of their application to an ET sensor array using the skills acquired during the Leicester secondment as detailed in Article 3. As detailed in the final chapter of this thesis, the insight into the imprinting process which was acquired during the research has been used to design a sensor array system which meets the specifications of ET experimental runs. This takes the form of the introduction of the research topic computationally selected polyelectrolytes, immobilised onto a voltammetric electrode surface via highly robust conducting graphite ink. Additional recommendations are also made to further enhance the on-going MIP projects within the laboratory, such as the separation of the MIP and the electrode to increase MIP regeneratibility. Some final suggestions for some other inter-institutional collaboration are also presented which aim to creating portable ET system for in-field sample collection and analysis

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We 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

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    We 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

    Author Index

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    Computational design of molecularly imprinted polymer for direct detection of melamine in milk

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    A novel protocol for use of molecularly imprinted polymer (MIP) in analysis of melamine is presented. Design of polymer for melamine has been achieved using a combination of computational techniques and laboratory trials, the former greatly reducing the duration of the latter. The compatibility and concerted effect of monomers and solvents were also investigated and discussed. Two novel open-source tools were presented which are the online polymer calculator from mipdatabase.com and the application of the Gromacs modelling suite to determine the ideal stoichiometric ratio between template and functional monomer. The MIP binding was characterised for several structural analogues at 1–100 μM concentrations. The use of divinylbenzene (DVB) as cross-linking polymer and itaconic acid as functional monomer allowed synthesis of MIP with imprint factor (IF) of 2.25 for melamine. This polymer was used in high-performance liquid chromatography (HPLC) for the rapid detection of melamine in spiked milk samples with an experimental run taking 7–8 min. This approach demonstrated the power of virtual tools in accelerated design of MIPs for practical applications

    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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
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