1,720,961 research outputs found
A multiple approach to the taxonomy of Lactarius rubrozonatus (Basidiomycota, Russulales)
No full textThe biometric and molecular data supporting the separation of the new
taxon Lactarius rubrozonatus from L. sanguifluus are discussed. The results of a
multidisciplinary examination led to separate two close taxa growing sympatrically
in symbiotic association with two-needle pines. Even though, morphologically, the
only reliable separating characters were pileal zonation and spore size, the autonomy
of the new taxon was supported by ITS sequences and the stop of genetic flux in five
allozymes. The new taxon, which was previously referred to as L. vinosus, was renamed
L. rubrozonatus because the older epithet was illegitimate
Caratterizzazione morfo-molecolare del taxon Panaeolus cyanescens var. bisporus
No full textVengono segnalate alcune raccolte di Panaeolus cyanescens var. bisporus, fatte in Abruzzo, e discussi gli aspetti tassonomici e nomenclaturali del taxon, con riferimenti alle specie più affini. Si riportano i risultati dell’analisi molecolare effettuata sul materiale raccolto confrontandoli con i dati disponibili in rete.Some recent collections of Panaeolus cyanescens var. bisporus from Abruzzi provided the opportunity of a reconsideration of its taxonomic and nomenclatural problems based on morphology and nucleotide sequence data. The resulting phylogram, incorporating all GenBank accessions available, presents evidence supporting the treatment of the taxon as a variety and of Copelandia as a subgenus, and highlights a close relationship with P. cambodginiensis. However, the sampling is still too limited and does not allow to draw final conclusions. The study includes a review of most of the literature on Copelandia, the taxon under consideration and its closest allies, and colour photographs of basidiomata and of their salient microanatomical features
Intraspecific isozyme variability in Italian populations of the white truffle Tuber magnatum
No full textI funghi del Monte Salviano
No full textViene fatto il punto sulla consistenza della biodiversità fungina, limitatamente ai macrofunghi, della riserva naturale del Monte Salviano, rilevata nel corso di circa quindici anni di indagini. E’ stata registrata la presenza di 288 specie, 44 delle quali Ascomiceti e 244 Basidiomiceti. La composizione della flora micologica rispecchia la situazione vegetazionale costituita da un mosaico di elementi residuali del fitoclima mediterraneo, precedenti il prosciugamento del bacino lacustre del Fucino, con presenze steppiche e specie esotiche introdotte con rimboschimenti di conifere. Alcune specie, quali Leucopaxillus lepistoides, Tricholoma tridentinum var. cedretorum, Agaricus jodosmus, Cortinarius herculeus e Radiigera atrogleba hanno avuto solo poche segnalazioni sul territorio italiano; mentre due, Gamundia lonatii e Gamundia hygrophoroides, sono note esclusivamente in questa area che rappresenta il loro locus typicus. Nel complesso la check-list fa registrare almeno 58 nuove specie alla flora micologica abruzzese. Vengono infine fornite due note tassonomiche in riferimento alle raccolte di fenotipi di Morchella atrotomentosa e M. pseudoumbrina, e di Neournula pouchetii.The check-list of the macrofungi from the natural reserve of Mt. Salviano includes 288 species, with 44 Ascomycetes and 244 Basidiomycetes. Fifty-eight of them have not hitherto been recorded for the Abruzzo’s mycoflora. The relation of the mycoflora with peculiar vegetational situations within the area is discussed and for three taxa (Morchella atrotomentosa and M. pseudoumbrina, and Neournula pouchetii.) two short taxonomic notes are provided. Two species, Gamundia lonatii and Gamundia hygrophoroides, previously described as new species from this very area, do not seem to have been recorded outside it
Expanding the understanding of a forest ectomycorrhizal community by combining root tips and fruiting bodies: A case study of Tuber magnatum stands
Full text linkA survey of both ectomycorrhizal (ECM) root tips and fruiting bodies of ECM fungi was carried out during a four-year period (2009–2012) in two similar forest stands in central Italy, previously investigated in detail being habitats of the Italian white truffle Tuber magnatum Pico. This research is one of the few conducted in mixed forest stands and, for the first time, it took into account the cryptic fungi (corticiaceous, hypogeous, and sclerotia). This survey led to an exhaustive description of the ECM community by integrating all the 197 taxa recorded (147 species as fruiting bodies, 65 as ectomycorrhizas, and 15 overlapping taxa recorded by both systems), and it also revealed a discrepancy between the results obtained using these two different approaches. In fact, a prevalence of Russulaceae, Inocybaceae, and Cortinariaceae resulted from fruiting body observations, whereas Thelephoraceae and Sebacinaceae dominated the ECM root tips. This result suggests a probable flaw in the sampling methodology. There may be several causes of this phenomenon, including the different nutritional strategies of ectomycorrhizal fungi and their seasonal turnover. Some species that could be candidates as bioindicators of T. magnatum habitat in mixed forest were identified
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
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