1,721,508 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
Electrochemiluminescence (ECL) sensing properties of water soluble core-shell CdSe/ZnS quantum dots/Nafion composite films
No full textWater soluble positively charged 2-(dimethylamino) ethanethiol (DAET)-protected core-shell CdSe/ZnS quantum dots (QDs) were synthesized and incorporated within negatively charged Nafion polymer films. The water soluble QDs were characterized using UV-visible and fluorescence spectroscopies. Nafion/QDs composite films were deposited on glassy carbon electrodes and characterized using cyclic voltammetry. The electrochemiluminescence (ECL) using hydrogen peroxide as co-reactant was enhanced for Nafion/QDs composite films compared to films of the bare QDs. Significantly, no ECL was observed for Nafion/QDs composite films when peroxydisulfate was used as the co-reactant, suggesting that the permselective properties of the Nafion effectively exclude the co-reactant. The ECL quenching by glutathione depends linearly on its concentration when hydrogen peroxide is used as the co-reactant, opening up the possibility to use Nafion/QDs composite films for various electroanalytical applications
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
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
Shear bond strength of different adhesives tested in accordance with DIN 13990-1/-2 and using various methods of enamel conditioning
No full textFür den Kliniker ist die Scherhaftfestigkeit eines Adhäsivs ein wichtiger
Parameter, da ein ungewollter vorzeitiger Bracketverlust in der Praxis ein
unerwünschtes nicht planbares Ereignis ist. Andererseits darf es beim
Entfernen von Brackets nicht zu Schmelzausrissen kommen. Es wird angenommen,
dass unterschiedliche Ätzmodi sich auf die Scherhaftfestigkeit auswirken. DIN
13990-1/-2 soll die Scherhaftfestigkeit von kieferorthopädischen Adhäsiven
einheitlich und reproduzierbar testen. Die Ziele der vorliegenden Studie
waren: 1\. die Praktikabilität von DIN 13990-1/-2 für den Anwender zu
untersuchen 2\. die Scherhaftfestigkeit der Adhäsive Transbond XT, Beauty
Ortho Bond und Fuji Ortho LC unter unterschiedlichen Ätzbedingungen zu
bestimmen Methode Die Schmelzoberfläche wurde im ersten Versuchsteil nach
Herstellerangaben konditioniert. Im zweiten Versuchsteil wurde die
Scherhaftfestigkeit nach zusätzlichem Ätzen oder nach Verwendung eines
aggressiveren Ätzmittels bestimmt. Die Studie umfasste 600 Versuche. Dafür
wurden 480 bovine bleibende Schneidezähne und 120 Brackets eingebettet. Jedes
Adhäsiv wurde im Einzelverbund Schmelz-Adhäsiv, Adhäsiv-Bracket (DIN 13990-1)
und im Gesamtverbund Schmelz-Adhäsiv-Bracket (DIN 13990-2) untersucht. Das
Abscheren der Brackets bzw. Prüfkörper erfolgte nach Lagerung für 15 min, 24 h
und 24 h mit anschließendem Thermocycling. Jeweils 10 Proben wurden
hinsichtlich Adhäsiv, Verbundsituation, Konditionierungsmodus und Lagerung
gleich behandelt. Die Brackets bzw. Prüfkörper wurden in einer
Universalprüfmaschine (Zwick Z010, Ulm) bei einer Traversengeschwindigkeit von
1 mm/min in okklusogingivaler Richtung abgeschert. Anschließend wurde mit
10-facher Vergrößerung die Bruchfläche bewertet und das Frakturmuster
bestimmt. Die statistische Auswertung und grafische Darstellung der
Scherversuche erfolgte mit Hilfe des Statistikprogramms SPSS für Windows
(Version 19.0). Die einfaktorielle ANOVA wurde unter Berücksichtigung der
Einflussfaktoren Adhäsiv, Verbundsituation, Konditionierungsmodus und Lagerung
angewendet. Zudem wurden t-Tests für unabhängige Stichproben durchgeführt.
Ergebnisse • Die Prüfung der Scherhaftfestigkeit nach DIN 13990-1/-2 ist ein
praktikables Verfahren, das reproduzierbare Ergebnisse liefert. • Die
Scherhaftfestigkeiten der Adhäsive sind in absteigender Reihenfolge am
höchsten bei Transbond XT, Beauty Ortho Bond, Fuji Ortho LC. • 500 Zyklen
Thermocycling bewirken bei den untersuchten Produkten keinen signifikanten
Unterschied der Scherhaftfestigkeit. • Aggressiveres Konditionieren führt zu
signifikant höheren Scherhaftfestigkeiten als Konditionieren nach
Herstellerangaben. • Die Wahl des Adhäsivs wirkt sich auf die Anzahl der
Schmelzausrisse aus. Die meisten Schmelzausrisse traten bei Transbond XT auf.
Bei Fuji Ortho LC waren zwei Schmelzausrisse zu verzeichnen. Beauty Ortho Bond
ließ keinerlei Schmelzausrisse erkennen. Schlussfolgerung Die in dieser Studie
untersuchten Adhäsive Transbond XT und Beauty Ortho Bond eignen sich für den
klinischen Einsatz. Fuji Ortho LC erfüllte nicht in allen
Versuchskonstellationen die – willkürlich festgesetzten –
Minimalanforderungen.High bond strength is desirable; however, enamel damage during debonding must
be avoided. At the same time premature loss of brackets during orthodontic
treatment is undesirable. Therefore, adhesive bond strength is an important
parameter for clinicians. Different types of enamel conditioning are supposed
to affect bond strength. DIN 13990-1/-2 describes standardized tests intended
to ensure comparability of results. The aims of this study were: 1\. to get
information about the suitability of DIN 13990-1/-2 and its recommendations
2\. to test the bond strength of the adhesives Transbond XT, Beauty Ortho Bond
and Fuji Ortho LC with various conditioning regimes Material and Methods In
the first part of the study the enamel surface conditioning was performed as
recommended by the manufacturers. In the second part of the study shear bond
strength was tested after additional conditioning or after using a stronger
etching substance. A total of 600 experiments were carried out, with groups of
10 specimens each subjected to identical treatments. Shear bond strengths of
all adhesives were evaluated separately at the bracket-adhesive and adhesive-
enamel interface (DIN 13990-1), as well as at the total (enamel-adhesive-
bracket) interface (DIN 13990-2). Shear bond strength (SBS) was tested after
storage for 15 min, after storage in distilled water at 37 °C for 24 h and
after 24 h followed by thermocycling. After storage, the bonded specimens were
tested for SBS using a universal testing machine (Zwick Z010; Ulm, Germany) at
a crosshead speed of 1 mm/min in occluso-gingival direction. After debonding
the fracture pattern was determined using an optical microscope at 10x
magnification and the failure pattern was assessed. Statistical software
(SPSS, v.19.0; IBM, Armonk, NY, USA) was used for analysis and graphical
presentation of the shear experiments. Analysis of variance (ANOVA) was
performed. Consideration was given to the different adhesives, enamel
conditioning, interface types and storage modes. T-tests for independent
samples were used. Results • DIN 13990-1/-2 is suitable to test shear bond
strength. Results are reproducible. • The highest shear bond strengths were
measured with Transbond XT, followed by Beauty Ortho Bond and Fuji Ortho LC. •
500 cycles thermocycling did not have a significant influence on the adhesives
tested. • Shear bond strength after stronger etching than recommended by the
manufacturer led to significantly higher shear bond strengths. • Most enamel
damages occurred with Transbond XT. Conclusion Transbond XT and Beauty Ortho
Bond are suitable adhesives for clinical needs. Fuji Ortho LC does not meet
our (arbitrarily defined) minimum requirements
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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