1,721,083 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
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
Toward a more realistic modelisation of biological systems
No full textLa plupart des fonctions énergie potentielle utilisées pour simuler les systèmes biologiques complexes ne traitent qu'implicitement la polarisation électronique et ce, de façon très incomplète. Bien qu'efficaces pour un large éventail d'applications, ces champs de force atteignent rapidement leurs limites dès lors que les effets de polarisation électronique sont importants. Tel est le cas par exemple au site actif des métalloprotéines où l'ion métallique polarise fortement son environnement. Dans cette thèse, j'ai développé une approche basée sur la mécanique quantique pour obtenir des paramètres d'un champ de force polarisable ayant pour composantes des charges, des polarisabilités distribuées d'ordre zéro et un (isotrope) et un potentiel de van der Waals décrit par une fonction de Buckingham. L'énergie d'induction peut être atténuée par une fonction de Tang et Toennies pour décrire l'énergie d'échange-induction. Cette approche a été effectuée avec succès pour l'interaction d'ions avec l'eau et le benzène mais aussi dans le cas d'un dimère d'eau. Une première étude des résultats en dynamique moléculaire montre que les paramètres obtenus en phase gazeuse peuvent se transférer pour les simulations en phase condenséeMost of the energy potential functional used in biological systems only treat electronic polarization implicitely and this, in an incomplete way. Even very effective for many applications, those force fields reach there limits when the polarization effects are important. This is the case, for example, at the active site of metalloproteins where the metallic ion heavily polarizes its environment. We will present a strategy to take into account the polarization through polarizability distributed on atoms obtained by quantum chemical calculations. The interaction energies have been compared with a reference SAPT (\textit{Symmetry Adapted Perturbation Theory}) calculation which permits to expand the interaction in electrostatics, induction and van der Waals contributions. I will present the interaction of ions with water, benzene and also water dimer interactions. Preliminary results in molecular dynamics seems to confirm that gas phase parameters can be transfered to condensed phas
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
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
Bases moléculaire de l'interaction protéine-protéine lors de la synaptogenèse
No full textLa capacité à déterminer rapidement et avec certitude si la liaison protéine-protéine est suffisamment forte pour avoir une fonction biologique est d'une importance primordiale dans le contexte de la découverte de médicaments in silico et des études fonctionnelles biologiques comme la synaptogénèse. Dans ma thèse, j'ai participé à l'établissement d'un protocole clair et complet utilisant la voie alchimique et géométrique pour les calculs standard de l'énergie libre de liaison absolue, qui reste le seul critère définitif pour estimer quantitativement l'affinité de liaison. J'ai étendu ce protocole aux complexes protéines-protéines dans le contexte de la syndémie COVID-19, contribuant à élucider la stratégie choisie par les variants préoccupants pour augmenter leur contagiosité tout en analysant la base moléculaire responsable de leurs affinités diverses pour ACE2. J'ai également renforcé les bases méthodologiques des calculs standard de l'énergie libre de liaison en démontrant la nécessité de restreintes pour obtenir des estimations précises en comparant la voie géométrique aux stratégies dépourvues de restreintes. De plus, j'ai participé à une exploration systématique méthodologique de la combinaison entre répartition de la masse de l'hydrogène et un pas de temps multiple pour le calcul des forces dans le but d'accélérer les calculs des énergies libres de liaison standard en utilisant l'approche de la voie géométrique. Cette étude a révélé la nécessité d'optimiser les paramètres impliqués dans le Lagrangien étendu de l'algorithme d'échantillonnage amélioré pour garantir la précision tout en améliorant la vitesse par un facteur de trois. Enfin, j'ai appliqué la voie géométrique à des complexes de synaptogenèse, avec la famille des Defective proboscis response (Dpr) et Dpr intercating proteins (DIP). J'ai pu retrouver des affinités correspondant aux données expérimentales avec la précision chimique. Cependant, ces calculs ont révélé la nécessité d'un réglage individuel et ne peuvent pas être réalisés dans l'ensemble de l'interactome Dpr-DIP en un temps raisonnable et sans intervention humaine. J'ai donc eu recours à des approches d'apprentissage automatiques, telles que l'analyse discriminante linéaire et la forêt aléatoire, en raison de leur capacité à traiter de grandes quantités de données et de leur interprétabilité. J'ai classifié avec précision les liaisons faibles et fortes dans cet ensemble de données, ce qui peut être utile dans l'analyse à haut débit. J'ai proposé des descripteurs d'entrée spécifiques, en exploitant les propriétés séquentielles, structurelles et physico-chimiques des protéines. Ces descripteurs d'entrée sont très généraux et pourraient être utilisés pour aborder des problèmes d'interaction entre protéines.The ability to rapidly ascertain with accuracy whether the binding of protein-protein is strong enough to have a biologically relevant function is of paramount importance in the context of in silico drug discovery and biological functional studies like those involve in synaptogenesis. In the thesis, I participated in establishing a clear and comprehensive protocol leveraging the alchemical and geometrical route for standard absolute binding free-energy calculations, which is the only definitive criterion to estimate the binding affinity quantitatively. I extended this protocol to protein-protein complexes in the context of the COVID-19 syndemic, helping to elucidate the strategy the variants of concerns had chosen to increase contagiosity while reasoning on the molecular basis responsible for their diverse affinities for ACE2. I also reinforce the methodological basis of the standard binding free-energy calculations by demonstrating the need for restraint to obtain accurate estimates in comparing restraint-based methods (the geometrical route) and unrestraint strategies. Furthermore, I participate in a methodological systematic exploration of the combination of hydrogen mass repartitioning and multiple time stepping to speed up the calculations of standard binding free energies using the geometrical route approach, revealing the need for carefully tuned hyperparameters involved in the extended Lagrangian of the enhanced sampling algorithm to guarantee accuracy while improving speed by a factor of three. Lastly, I employed the geometrical route on complexes from synaptogenesis, the Defective proboscis extended response (Dpr), and the Dpr interacting proteins (DIP). I could recover experimental binding free-energy matching experimental data up to chemical accuracy. However, these calculations revealed a need for individual tunning and cannot be performed to the full extent of the Dpr-DIP interactome in a reasonable time. I resorted to machine learning approaches, Linear Discriminant Analysis, and Random Forest for their ability to handle large amounts of data and interpretability. I accurately classified weak and strong binders in this dataset, which can be helpful in high-throughput analysis. I proposed specific input features, leveraging sequence, structural, and physicochemical properties. These input features are very general and could be used to tackle protein-interacting problems
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
