1,721,095 research outputs found
ESCRT-III assembly and cytokinetic abscission are induced by tension release in the intercellular bridge
No full textThe last step of cell division, cytokinesis, produces two daughter cells that remain connected by an intercellular bridge. This state often represents the longest stage of the division process. Severing the bridge (abscission) requires a well-described series of molecular events, but the trigger for abscission remains unknown. We found that pulling forces exerted by daughter cells on the intercellular bridge appear to regulate abscission. Counterintuitively, these forces prolonged connection, whereas a release of tension induced abscission. Tension release triggered the assembly of ESCRT-III (endosomal sorting complex required for transport-III), which was followed by membrane fission. This mechanism may allow daughter cells to remain connected until they have settled in their final locations, a process potentially important for tissue organization and morphogenesis
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
Temporal regulation of the abscission, the last step of cell division : role of forces exerted on the intercellular bridge
No full textLa dernière étape de la cytocinèse, l’abscission, consiste en la coupure du pont intercellulaire reliant les deux cellules filles à la suite de la contraction de l’anneau acto-myosique. Comme toutes les étapes de la division cellulaire, l’abscission doit être régulée dans l’espace et dans le temps afin qu’elle intervienne au bon endroit et au bon moment. Mon travail de doctorat a porté sur l’étude de la régulation dans le temps de l’abscission par l’environnement des cellules filles, en particulier par les forces de traction exercées par les cellules sur le pont intercellulaire. En utilisant une combinaison d’approches permettant de contrôler le confinement spatial 2D des cellules filles, de mesurer les forces exercées par les cellules au cours de la cytocinèse et de micro-manipuler le pont intercellulaire, j’ai montré que, de façon contre-intuitive, une tension exercée au niveau du pont retardait l’abscission et qu’au contraire la relâche de cette tension induisait l’abscission. De plus, la régulation temporelle de l’abscission par les facteurs environnementaux des cellules filles implique les protéines des « Endosomal Sorting Complex Required for Transport III » (ESCRT-III), machinerie centrale de l’abscission. Enfin, des expériences préliminaires suggèrent que cette régulation serait importante pour le maintien de l’intégrité tissulaire et la morphogenèse au cours du développement.The last step of cytokinesis, abscission, consists in the severing of the intercellular bridge connecting the two daughter cells after the contraction of the acto-myosin ring. As any other step of cell division, abscission has to be regulated both in time and space in order to take place at the proper time and proper place. During my PhD, I studied the temporal regulation of the abscission by the cell micro-environment, particularly by the traction forces exerted by the cells on the intercellular bridge. I used a combination of approaches to control the daughter cells 2D spatial confinement, to measure the forces exerted by the cells throughout cytokinesis, and to micro-manipulate the intercellular bridge. Counter-intuitively, a tension exerted on the intercellular bridge delayed abscission while a release of tension in the bridge induced abscission. Moreover, the temporal regulation of abscission by the environment of the daughter cells implies the Endosomal Sorting Complex Required for Transport III (ESCRT-III), the main abscission machinery. Finally, preliminary experiments suggest that this mechanism could be important for tissue integrity and morphogenesis
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
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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