1,721,134 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
The Intimate Role of Imidazole in the Stabilization of Silicic Acid by a pH-Responsive, Histidine-Grafted Polyampholyte
No full textA methacrylate-based polyampholyte homopolymer was synthesized starting
from N-methacryloyl-L-histidine (MHist). This paper reports the inhibitory effects of poly-Nmethacryloyl-L-histidine
(poly-MHist) on the in vitro silicic acid condensation. In particular,
the ability of poly-MHist to retard silicic acid condensation in aqueous supersaturated
solutions at three pH values, 5.5, 7.0, and 8.5, is studied. The direct role of the imidazole ring
was confirmed by substantial changes in silicic acid stabilization efficiency based on the
following observations: (a) the protonation degree of the imidazole ring affects stabilization. At
a relatively low pH of 5.5, the imidazole is protonated and the entire polymer acquires a
zwitterionic character (−COO− is also present). Inhibitory activity increases considerably. In
contrast, at a high pH of 8.5, the imidazole ring is neutral and the polymer backbone is anionic
due to the presence of −COO− moieties. This results in total inactivity with respect to silicic
acid stabilization. (b) The use of a similar, but pH-insensitive derivative poly(N-acryloyl-Lphenylalanine)
(poly-PHE), which contains a phenylalanine instead of histidine, results in total
loss of silicic acid stabilization activity. Finally, poly-MHist also shows effects on colloidal silica
particle morphology. Increasing the poly-MHist concentration results in a reduced size of silica particles
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
Fortschritte in schwingungsspektroskopischen Methoden zur Untersuchung von Diatomeen und Humanzellen
No full textDiatomeen sind einzellige, eukaryotische Mikroorganismen, die den Hauptbestandteil des marinen Phytoplanktons ausmachen. Sie stellen aufgrund ihrer vorwiegend autotrophen Lebensweise sowohl wichtige Primär- als auch Sauerstoffproduzenten dar und assimilieren täglich etwa 20 % des atmosphärischen Treibhausgases CO2, wodurch sie entscheidend zur Klimaregulation beitragen. Die hohe Verbreitung von Diatomeen in Süßwassern veranlasste Wissenschaftler zu dem Vorschlag, Diatomeen als Bioindikatoren für die Eutrophierung von Seen und Flüssen zu nutzen. Auch in wirtschaftlicher Hinsicht könnten Diatomeen in Zukunft eine entscheidende Rolle auf dem Gebiet der Biokraftstoffproduktion spielen. Um hierbei optimale Wachstumsbedingungen in den Bioreaktoren sicherzustellen, ist es erforderlich, zellphysiologische Änderungen in Abhängigkeit der Kultivierungsbedingungen nachzuvollziehen. Konventionelle Methoden wie Hochleistungsflüssigkeitschromatographie (HPLC) oder Gaschromatographie (GC) erlauben quantitative Aussagen über die mittlere makromolekulare Zusammensetzung der Kultur, haben aber den Nachteil, dass sie schwerlich in kontinuierliche Prozesskontrollverfahren einzubinden sind und aufwendige sowie invasive Probenvorbereitungsschritte erforderlich machen. Das Ziel der vorliegenden Arbeit ist es, die Eignung schwingungsspektroskopischer Methoden, insbesondere der Raman-Spektroskopie, für die in vivo Untersuchung der Zellphysiologie von Diatomeen zu überprüfen. In diesem Zusammenhang wird eine Bandbreite Raman-spektroskopischer Messmodalitäten entwickelt und angewandt, die von der konventionelle Raman- Mikrospektroskopie mit punkt- sowie linienförmigem Laserfokus über eine Hochdurchsatzvariante mit automatisierter Zellerkennung bis hin zur Kombination von Raman-Spektroskopie mit Mikrofluidik reicht
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
Beyond Spin Exchange Optical Pumping: Hyperpolarization of 129Xe via Sublimation Dynamic Nuclear Polarization
No full textGR-C
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
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