1,721,038 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
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
A coding region in Diaporthe helianthi reveals genetic variability among isolates of different geographic origin
No full textA set of Diaporthe helianthi isolates collected in different geographic areas was studied in order to examine
whether different genetic biotypes could be responsible for epidemiological differences shown by sunflower
stem canker. D. helianthi causes serious losses in France and in former Yugoslavia, while the pathogen
is only sporadically recorded in Italy in spite of conducive pedoclimatic conditions. Variability of a
D. helianthi coding genomic region, evaluated by means of polymerase chain reaction (PCR), Southern blot
hybridisation and restriction fragments length polymorphism (RFLP), showed a conserved homogeneous
pattern shared by French and Yugoslavian isolates compared with the heterogeneous pattern of Italian
isolates. These results are consistent with other investigations (IGS and ITS region variability) performed
on the same set of isolates, allowing a correlation between D. helianthi biotypes, their geographic origin and
sunflower stem canker epidemiology
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Variability in Diaporthe helianthi isolates of different geographic origin at coding sequences level
No full textDiaporthe helianthi (Phomopsis helianthi), agente del cancro dello stelo, è uno dei più importanti patogeni del girasole in Europa, ma non risulta particolarmente aggressivo in Italia. I funghi fitopatogeni producono uno spettro di enzimi che degradano la parete cellulare vegetale, tra i quali le pectinasi svolgono un ruolo importante, poiché degradano uno dei principali componenti della parete cellulare e della lamella mediana. Al momento in letteratura non è disponibile alcuna informazione circa la produzione di specifici enzimi pectinolitici in D.helianthi.
In questo studio abbiamo confrontato 12 isolati di D.helianthi di origine geografica diversa, per i quali sono note anche differenze di virulenza sul girasole, al fine di individuare la presenza di geni per l’endo-poligalatturonasi (endo-PG) e di valutarne la variabilità. A questo scopo sono stati condotti esperimenti di PCR, utilizzando una coppia di oligonucleotidi degenerati costruiti sulla sequenza del gene endo-PG (pgA) di Fusarium moniliforme. I profili di amplificazione ottenuti sono risultati interessanti in quanto diversi tra gli isolati, in relazione all’origine geografica. In particolare i pattern degli amplificati derivati da DNA genomico di isolati francesi ed yugoslavi risultano simili, mentre quelli ottenuti con DNA di isolati italiani, rumeni o argentini sono molto variabili.
Sono stati quindi effettuati esperimenti di Southern blot per confermare l’identità dei prodotti di amplificazione, utilizzando come sonda il gene clonato per l’endo-PG (pgA) di F.moniliforme. La sonda ha ibridato con la maggior parte dei prodotti di amplificazione, anche se con livelli di riconoscimento diversi.
Il prodotto di amplificazione principale degli isolati francesi ed yugoslavi è stato selezionato come rappresentativo delle sequenze conservate in questo gruppo di isolati. Uno degli isolati francesi è stato scelto per avviare l’analisi di sequenza. Dal confronto del prodotto di amplificazione di D.helianthi con le sequenze note di endo-PG in letteratura emerge un allineamento variabile, in accordo con la divergenza riscontrata tra questi geni nelle varie specie fungine. Inoltre una ricerca in banca dati evidenzia una omologia significativa tra la sequenza di D.helianthi e un gene di Aspergillus terreus per una polichetide sintasi, come già descritto in letteratura per un gene endo-PG di Botrytis cinerea (BcPGA2).
Lavoro svolto nell’ambito del Programma di Ricerca di Interesse Nazionale (MURST, finanziamento 1999) “Diaporte helianthi – girasole: studio di un patosistema”
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