1,721,080 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
Retinal Pigment Epithelium Derived from Mouse Embryonic Stem Cells Enhances Photoreceptor Differentiation in Retinal Organoids
Full text linkDie Netzhaut der Wirbeltiere ist ein mehrschichtiges neuronales Gewebe, das sich aus der Neuroretina und dem retinalen Pigmentepithel (RPE) zusammensetzt. Die Neuroretina beinhaltet einen Glia- und sechs neuronale Zelltypen, die Informationen mittels lichtsensitiver Fotorezeptorzellen aufnehmen, verarbeiten und weiterleiten. Die Fotorezeptoren sind im RPE eingebettet, das wichtige Funktionen in der Entwicklung und Instandhaltung der Retina übernimmt. Melanosomen im RPE sind Kompartimente, deren Hauptaufgabe darin besteht Licht zu absorbieren Da das RPE die Blut-Retina-Schanke aufbaut, vermittelt es den Austausch von Molekülen zwischen Retina und Aderhaut. Außerdem phagozytieren RPE-Zellen die äußeren Segmente der Fotorezeptoren und regenerieren deren Sehpigment in mehreren enzymatischen Schritten.
In der dreidimensionalen Zellkultur gibt es Methoden zur Herstellung von organähnlichen Strukturen, die Organoide genannt werden. Mithilfe etablierter Protokolle können Strukturen ähnlich der Netzhaut entwickelt werden, die sich selbstorganisierend in retinale Organoide (ROs) ausdifferenzieren. In diesen Organoiden sind RPE-Zellen jedoch zu meist nicht vorhanden oder nicht in der räumlichen Nähe und Anordnung zu den neuroretinalen Arealen.
In dieser Arbeit wurden RPE-Zellen separat aus embryonalen Stammzellen der Maus (mESZ) differenziert. Die mESZ-RPE-Zellen exprimierten RPE spezifische Markergene, deren Expression mittels digital droplet PCR gemessen wurde. In Immunfärbungen konnte sowohl die morphologische als auch strukturelle Maturation der Zellen gezeigt werden. Die mESZ-RPE-Zellen wurden auf permeablen Membranen kultiviert, die den Austausch von Nährstoffen erlauben, was den Aufbau der Blut-Retina-Schranke nachstellt. Da ROs kein vollständig maturiertes retinales Gewebe aufweisen, wurde ein in vitro Co-Kultivierungssystem mit RPE-Zellen und ROs etabliert, welches es erlaubt die gemeinsame Entwicklung der beiden Gewebe zu verfolgen und zu untersuchen.
ROs können für einen Zeitraum von drei bis sechs Tagen mit RPE-Zellen kultiviert werden. Per Immunohistochemie konnte in Gefrierschnitten von ROs eine Erhöhung der Anzahl an Otx2 und Crx exprimierenden Fotorezeptoren ermittelt werden. Lösliche Faktoren, die von den RPE-Zellen abgegeben werden, haben auf ROs einen ähnlichen Effekt. Expressionsmuster der Proliferations- und Mitosemarker Ki67 und phosphoryliertes Histon H3 ser10 belegen, dass Neurogenese in ROs nach dem Mechanismus der interkinetischen Zellkernmigration erfolgt. Die Co-Kultivierung von mESZ-RPE hat einen starken Einfluss auf die Differenzierung von Fotorezeptoren in ROs und gibt Einblicke in die Interaktion von Neuroretina und RPE, um Mechanismen der in vivo Retinogenese besser verstehen zu können
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
Molekulare und zelluläre Auswirkungen einer Defizienz des Schizophrenie-Suszeptibilitätsgens Neuregulin 1 auf die Ausbildung des frontalen Cortex der Maus
Full text linkAuthor-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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