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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
Morphologische und molekulare Charakterisierung des Pathogens Colletotrichum gloeosporioides an Gaultheria mit dem Ziel der Erschließung von Resistenzquellen
Get PDFGaultheria procumbens L. ist in der Herbstvermarktung eine der bedeutendsten Zierpflanzen. Die winterharte, mehrjährige und sich über Rhizome bzw. Samen vermehrende Art der Familie Ericaceae kann massiv vom ubiquitär vorkommenden pilzlichen Pathogen Colletotrichum gloeosporioides befallen werden. Hat sich der Erreger einmal im Bestand etabliert, kann dies mitunter zu Totalausfällen führen, in deren Folge die Betriebe den Anbau der Gaultherien aufgeben müssen. Eine Bekämpfung der Mykose stellt sich als besonders schwierig heraus, da das Pathogen latent in der Pflanze vorkommt und Fungizide nur in der juvenilen Phase erfolgversprechend eingesetzt werden können. Ältere Pflanzen erzeugen zudem einen sehr dichten Bestand, sodass das Fungizid nicht mehr an die Stängelbasis gelangen kann, wo das Pathogen hauptsächlich lokalisiert ist. Eine Alternative zum Einsatz von Pflanzenschutzmitteln stellt die Züchtung dar. Mit der Nutzung pflanzengenetischer Ressourcen besteht die Möglichkeit der Entwicklung krankheitsresistenter Formen. Daher lagen die Schwerpunkte dieser Arbeit (1) in der Sammlung, Erhaltung, Vermehrung und Hybridisierung von Gaultheria-Arten, (2) in der Charakterisierung des Pathogens für die Entwicklung eines reproduzierbaren und praktikablen Resistenztests sowie (3) in der Resistenzevaluierung ausgewählter Gaultheria-Arten. Insgesamt konnten 23 der 33 im Gewächshaus kultivierten Gaultheria-Arten erfolgreich auf Anderson-Medium mit Phytohormonzusätzen (9 μM/l Zeatin, 5,7 μM/l Indol-3-essigsäure) als In-vitro-Sprosskultur etabliert werden. Mit Hilfe von 185 Random Amplified Polymorphic DNA Markern erfolgte eine Verwandtschaftsanalyse in der Gattung Gaultheria, die die Basis für anschließende Artkreuzungen bildete. In deren Folge konnten drei interspezifische Hybriden aus G. myrsinoides x G. procumbens gewonnen und molekulargenetisch über RAPD Marker bestätigt werden. In-vitro-Untersuchungen zur Langzeitlagerung von Gaultheria-Pollen machten deutlich, dass Pollen von G. procumbens bei einer dreimonatigen Lagerung bei -20 °C noch bis zu 50 % und bei G. shallon bis zu 70 % keimfähig bleiben kann. Mit zeitlich zunehmender Tiefkühllagerung verringerte sich die Keimrate und ging nach sechs Monaten gegen Null. Hinsichtlich des Pathogens C. gloeosporioides erfolgten Analysen zur Morphologie, Genetik und Virulenz. Anhand der Sequenzanalyse der rDNA-ITS-Region von 30 Isolaten und des Abgleichens der Sequenzen mit veröffentlichten Sequenzen der NCBI Datenbank via BLAST konnte gezeigt werden, dass neben C. gloeosporioides auch C. acutatum an Gaultheria vorkommt. Weiterführende Untersuchungen zum pathogenen Potential ergaben, dass C. acutaum apathogen ist. In einem PCR-basierten Nachweis von C. gloeosporioides aus infiziertem Pflanzenmaterial unter Anwendung von Additiven und Touch-Down-PCR konnten nur unspezifische Amplifikate erzeugt werden. In der Bewertung morphologischer Merkmale wie radiales Myzelwachstum, Koloniefarbe, Myzelstruktur, Setaen- und Konidienmassebildung sowie der Konidienlänge und -breite waren große Differenzen zwischen den 27 untersuchten Isolaten zu beobachten. Es wurden weiterhin Versuche zur Lokalisierung des Erregers an latent befallenen Gaultheria-Trieben durchgeführt mit dem Ergebnis, dass sich das Pathogen hauptsächlich im Wurzelbereich der Pflanze akkumuliert. Diese Resultate bildeten die Grundlage für Substratinfektionsversuche. Inokuliertes Substrat ermöglichte dabei innerhalb von vier Wochen eine Infizierung der Pflanze. Mit den Resistenztestungen über die etablierte Methode der Stängelgrundapplikation konnte eine Art (G. shallon) gegenüber dem hoch virulenten Isolat (P-14) als gering anfällig eingestuft werden. Die Arten G. procumbens, G. pumila und G. hispida reagierten auf das hoch virulente Pathogen mit starken Symptomausprägungen und wurden daher als sehr anfällig eingeordnet.Gaultheria procumbens L. is an important horticultural species in Germany. It is cultivated and used as an ornamental plant for the fall season. The perennial and hardy Ericaceous shrub propagates via seeds and rhizomes. Over the last years, German Gaultheria producers have suffered from enormous losses up to collapses of the whole crop due to the infection with the fungus Colletotrichum gloeosporioides. Only frequent applications of fungicides in the juvenile phase prevent the expansion of the pathogen. In older plants the application of fungicides is less effective and preventive, since the fungus colonizes the lower stem part which cannot be reached by fungicides. An alternative to the application of fungicides is the use of plant genetic resources as disease resistance donors and the development of resistant cultivars. Therefore, the focus of this work was (1) on the collection, maintenance, reproduction and hybridization of different Gaultheria species, on (2) the characterization of the pathogen for the development of a reproducible and practicable resistance test as well as (3) on the evaluation of resistance in selected Gaultheria species. Overall, out 23 of 33 Gaultheria species cultivated in the greenhouse were successfully established on Anderson\u27s medium as in vitro shoot cultures. In further cultivations on Anderson\u27s medium supplemented with phytohormons (9 μM/l zeatin, 5,7 μM/l indole-3-acetic-acid) more shoots were successfully established from shoot segments than from shoot tips. Genetic relationships in the genus Gaultheria were analysed using 185 Random Amplified Polymorphic DNA markers and formed the basis for interspecific hybridisations. Three interspecific hybrids of G. myrsinoides x G. procumbens were molecularly identified by RAPD markers. Studies on the long-term storage of Gaultheria pollen in vitro revealed that pollen from G. procumbens stored for up to three months at -20 °C retains 50 % and from G. shallon 70 % germinating rate. With temporal increasing cold storage germinating rate decreased and went to zero after six months. Concerning to the pathogen C. gloeosporioides the morphological and genetic variability plus its virulence potential were investigated. Based on sequence analysis of the rDNA ITS region in comparison to published sequences in the BLAST database, C. gloeosporioides and C. acutatum were shown to infect Gaultheria. Studies on the pathogenic potential confirmed that C. acutatum is non-pathogenic. In a PCR-based detection of C. gloeosporioides in infected Gaultheria plant material no specific amplicons were obtained, when applying additives and touch-down PCR programmes. The evaluation of morphological characteristics such as radial mycelial growth, colony color, and structure of mycelium, setae formation and mass propagation of conidia as well as their length and width indicated huge differences between the 27 tested isolates. Further experiments were performed on latently infected Gaultheria shoots. They demonstrated that the pathogen accumulates mainly in the root zone of the plant. These results formed the basis for substrate infection experiments, in which contaminated substrate led to an infection of Gaultheria plants within four weeks. Resistance tests showed that G. shallon was less susceptible against a highly virulent isolate (P-14) than G. procumbens, G. pumila and G. hispida when applying a spore suspension at the stem base
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
Evaluation of resistance of Gaultheria to Colletotrichum gloeosporioides under in vitro conditions
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