1,720,962 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
Individuazione di fitoplasmi in colture di Monarda fistulosa L.
No full textLa monarda, nota anche come erba bergamotto (Monarda fistulosa L.), appartiene alla grande famiglia delle Lamiaceae; si tratta di una specie erbacea perenne originaria del Nord America, dalle foglie ovato-lanceolate ed i fiori riuniti in verticilli terminali di colore lilla o violetto. Possiede proprietà antisettiche, digestive ed antispasmodiche, ma può essere impiegata anche a scopo culinario (le foglie fresche rientrano nella preparazione di insalate, frittate, macedonie, tè aromatici, ecc.). Nel mese di luglio 2009 è stata osservata in un piccolo impianto di monarda allestito nel Giardino delle Erbe “Augusto Rinaldi Ceroni” di Casola Valsenio (Ravenna; Emilia-Romagna) una malattia tipicamente riferibile alla presenza di fitoplasmi. Il 50% delle piante presenti risultava colpito e presentava sintomi di nanismo, giallume fogliare, virescenza e malformazioni dei verticilli fiorali. Campioni fogliari sintomatici ed asintomatici sono stati prelevati e sottoposti alle analisi di laboratorio per individuare ed identificare i fitoplasmi eventualmente presenti. Dopo estrazione degli acidi nucleici mediante un metodo che prevede l’uso di cloroformio e fenolo, effettuata da 1 gr. di materiale floematico, è stata applicata la tecnica PCR sul gene ribosomico 16S. Dopo una reazione diretta effettuata utilizzando i primers P1/P7 è stato necessario eseguire una riamplificazione (‘nested’ PCR) dei prodotti ottenuti mediante i primers R16F2/R2, interni ai precedenti, per poter visualizzare in gel di agarosio gli amplificati della lunghezza attesa (1.200 nucleotidi). Sono quindi state effettuate analisi del polimorfismo della lunghezza dei frammenti di restrizione (RFLP) su questi amplificati con gli enzimi TruI, TaqI e Tsp509I per 16 ore a 65°C. La comparazione dei profili di restrizione ottenuti dai campioni di monarda con quelli ottenuti dall’amplificazione di ceppi di fitoplasmi già classificati, non ha permesso di identificare i fitoplasmi presenti come ascrivibili a nessuno dei gruppi finora descritti sia dopo amplificazione reale, sia ottenuti dalla restrizione virtuale di sequenze depositate in banca-dati. Ulteriori indagini mediante il sequenziamento degli amplificati e l’uso di ulteriori enzimi di restrizione sono in corso per verificare la posizione tassonomica del nuovo fitoplasma, necessaria per poterne studiare l’epidemiologia ed in particolare per individuarne i vettori in campo. Malattie associate a fitoplasmi sono state già descritte in specie appartenenti al genere Monarda, in particolare in Canada. Qui alla fine degli anni novanta, fitoplasmi del gruppo 16SrI-B (giallume dell’astro, Aster yellows (AY) sono stati identificati in coltivazioni di M. fistulosa con sintomatologie simili a quella riscontrata in Italia. Nel nostro Paese questa rappresenta comunque la prima segnalazione di fitoplasmosi in questa specie
Identification and molecular characterization of multiple phytoplasma infection in Spartium junceum and Cytisus scoparius
No full textTwo genera of the Fabaceae family showed phytoplasmas symptoms in different locations in Europe i.e. Germany and Italy. Spartium junceum L. (Spanish broom) is a deciduous shrub with dark green, round stems and alternate leaves; inflorescences are terminal clusters of several bright yellow somewhat fragrant flowers. This ornamental shrub is frequently spontaneously growing especially in southern Italy where it is affected by spartium witches’ broom (SpaWB) disease, characterized by proliferation of axillary buds and stem fasciation. Two different phytoplasmas have been associated to SpaWB: ‘Candidatus Phytoplasma spartii’ (group 16SrX-D) and a phytoplasma belonging to elm yellows group (16SrV-C). Both were reported associated with SpaWB in Italy while only ‘Ca. P. spartii’ was reported in Spain. In the spring of 2011, typical SpaWB symptoms were observed in a plant up to 2 m tall growing in the city of Ercolano (Campania region, Italy). A similar symptomatology was observed in a group of shrubs of Cytisus scoparius (L) syn. Sarothamnus scoparius, better known as common broom or scotch broom growing in Dahlem botanical garden in Berlin (Germany). This is a perennial shrub native to western and central Europe, but it is considered invasive plant in areas such as North America and New Zealand.
Symptomatic and asymptomatic samples were collected in both cases: five samples of C. scoparius and two of S. junceum were analysed for phytoplasma presence by nested-PCR assays employing primer pairs P1A/P7A followed by F1/B6 and R16F2n/R2, phytoplasma identification was achieved by RFLP analyses with Tru1I on the two latter amplicons. Further confirmation of phytoplasma identity was achieved by nested-PCR assays with primers specific for phytoplasma groups 16SrI, 16SrV and 16SrX. All symptomatic samples produced amplicons of the expected lengths and no product was amplified from asymptomatic plants and using 16SrV specific primers.
Identification and classification of phytoplasmas allow to detect ‘Ca. P. spartii’ subgroup 16SrX-D and ‘Ca. P. asteris’ subgroup 16SrI-B in both genera. In some of the samples of C. scoparius also stolbur phytoplasmas were identified. Further phytoplasma characterization was carried out on tuf gene using a cocktail primers mix that was able to amplify phytoplasmas identified as ‘Ca. P. asteris’ in S. junceum and phytoplasmas showing two different Tru1I profiles in C. scoparius from Germany that are not present in any published RFLP profile on this gene. Direct amplicon sequencing is in progress in order to verify possible affiliation to ‘Ca. P. spartii’ group since the only available sequences of this gene on phytoplasmas are deposited in Qbank since they were obtained from the Qbol EU project
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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