1,720,957 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
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
Totalsynthese, Überarbeitung der endgültigen Struktur und biologische Bewertungen von Paenilamicin B2
No full textExploration of secondary metabolites produced by insect pathogenic bacteria has emerged as a successful strategy to identify novel bioactive chemical entities and to shed light on ecology and evolution of bacterial defensive mechanisms.
The paenilamicins are a group of four complex secondary metabolites produced by the honey bee brood pathogen Paenibacillus larvae – a causative agent of the worldwide spread devastating American Foulbrood disease. Structurally paenilamicins are linear polycationic polyketide-peptide hybrids bearing unusual hydroxylated and N-methylated building blocks, as well as D-amino acids and a polyamine moiety. The paenilamicins show antibacterial and antifungal activities while not affecting the mortality of bee larvae and only influencing the time course of the disease, which led to the hypothesis that the main function of paenilamicin is to outcompete ecological niche competitors of Paenibacillus larvae in the honey bee larval gut. The first identification and characterization of paenilamicins was accomplished by SÜSSMUTH et al. employing chromatography methods and NMR spectroscopy. Since then, continuous efforts towards the total synthesis of paenilamicin have been being made, finally resulting in two stereoisomers which showed no identity to the natural product.
This doctoral thesis aimed to achieve the final total synthesis of the correct stereoisomer of paenilamicin B2, motivated by the fact that the total synthesis is a powerful tool for an unambiguous structural confirmation and is crucial for sufficient supply for exploring biological functions and understanding structure-activity relations.
As continuation of previous efforts towards the total synthesis of paenilamicins in our group, this work shows the synthesis of the all necessary non-proteinogenic amino acid building blocks, their assembly to the final correct stereoisomer of paenilamicin B2 and revision of the originally reported structure. Special attention is paid to the synthesis of the correct isomers of galantinic acid (Gla) and agmatinamic acid (Aga) fragments. Sufficient supply of paenilamicins enabled further evaluation of their biological activities. These studies revealed the N-terminal fragment of paenilamicin as an important pharmacophore for antimicrobial activity and for mediating the self-resistance in the producer organism P . larvae. Additional in vivo experiments of paenilamicins corroborate their role of an agent to control the number of bacterial competitors. Finally, the data is shown that classifies paenilamicins as potential ribosome inhibitors.Die Erforschung von Sekundärmetaboliten, die von insektenpathogenen Bakterien produziert werden, hat sich als erfolgreiche Strategie zur Identifizierung neuer bioaktiver chemischer Einheiten und zur Aufklärung der Ökologie bakterieller Abwehrmechanismen erwiesen. Paenilamicine sind eine Gruppe von vier komplexen Sekundärmetaboliten, die vom Honigbienenbrutpathogen Paenibacillus larvae produziert werden – einem Erreger der weltweit verbreiteten verheerenden Bienenkrankheit Amerikanische Faulbrut. Strukturell sind Paenilamicine lineare polykationische Polyketid-Peptid-Hybride, die ungewöhnliche hydroxylierte und N-methylierte Bausteine, D-Aminosäuren sowie eine Polyamineinheit tragen. Paenilamicine wirken antibakteriell und antimykotisch ohne sich direkt auf die Mortalität der Bienenlarven auszuwirken. Sie beeinflussen stattdessen den zeitlichen Verlauf der Krankheit, was zur Hypothese führte, dass die Hauptfunktion von Paenilamicinen in der Bekämpfung ökologischer Nischenkonkurrenten von Paenibacillus larve im Honigbienenlarvendarm besteht.
Die erste Identifizierung und Charakterisierung von Paenilamicinen gelang SÜSSMUTH et al. unter Einsatz von chromatographischen Methoden und NMR-Spektroskopie. Seitdem wurden kontinuierliche Anstrengungen zur Totalsynthese von Paenilamicin unternommen, was zur Synthese von zwei Stereoisomeren führte, die mit dem Naturstoff nicht identisch waren.
Das Ziel dieser Dissertation ist es die abschließende T otalsynthese des korrekten Stereoisomers von Paenilamicin B2 zu erreichen, motiviert durch die Tatsache, dass die chemische Totalsynthese von Naturstoffen einerseits ein mächtiges Werkzeug zur eindeutigen Strukturaufklärung ist und andererseits zur Bereitstellung ausreichender Stoffmengen für die Erforschung ihrer biologischen Funktion und zum Aufklärung ihrer Struktur-Aktivitäts- Beziehungen dient.
Als Fortsetzung der systematischen Anstrengungen zur Totalsynthese von Paenilamicin in unserem Arbeitskreis zeigt diese Doktorarbeit den Weg zur Synthese aller notwendigen nicht- proteinogenen Aminosäurebausteine, deren Zusammenbau zum korrekten Stereoisomer von Paenilamicin B2, sowie die Revision der ursprünglich berichteten Struktur. Besonderes Augenmerk wird auf die Synthese der korrekten Stereoisomere von Galantinsäure (Gla) und Agmatinamsäure (Aga) gelegt. Ein ausreichender Nachschub mit Paenilamicin ermöglichte weitere Bewertungen ihrer biologischen Aktivitäten. Diese Studien zeigten, dass das N- terminale Fragment von Paenilamicin einen wichtigen Pharmakophor für die antimikrobielle Aktivität und für die Vermittlung der Selbstresistenz im Produzentenorganismus P. larvae darstellt. Zusätzliche in vivo Experimente von Paenilamicine bestätigen seine Rolle als ein Wirkstoff zur Kontrolle der Anzahl bakterieller Konkurrenten. Schließlich werden die ersten Daten gezeigt, die Paenilamicine als potentielle Ribosomeninhibitoren einstufen
PLC-Automated Bayer Process in Aluminium Manufacturing
No full textDescribes the importance of Bayer Process in Aluminium Manufacturing. Follows detailed description of Bayer Process, its specifications, and provides the real electrical components for implementation of the system. Constructs PLC program for automation of the process, prepares an IO list, describes the touch screen programs and web-visualization. Shows the testing environment and results of the testing of the implemented system.BSc/BAElectrical Engineerin
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
