1,725,492 research outputs found
Molecular taxonomy of bambusicolous fungi: Tetraplosphaeriaceae, a new pleosporalean family with Tetraploa-like anamorphs
No full textAbstractA new pleosporalean family Tetraplosphaeriaceae is established to accommodate five new genera; 1) Tetraplosphaeria with small ascomata and anamorphs belonging to Tetraploa s. str., 2) Triplosphaeria characterised by hemispherical ascomata with rim-like side walls and anamorphs similar to Tetraploa but with three conidial setose appendages, 3) Polyplosphaeria with large ascomata surrounded by brown hyphae and anamorphs producing globose conidia with several setose appendages, 4) Pseudotetraploa, an anamorphic genus, having obpyriform conidia with pseudosepta and four to eight setose appendages, and 5) Quadricrura, an anamorphic genus, having globose conidia with one or two long setose appendages at the apex and four to five short setose appendages at the base. Fifteen new taxa in these genera mostly collected from bamboo are described and illustrated. They are linked by their Tetraploa s. l. anamorphs. To infer phylogenetic placement in the Pleosporales, analyses based on a combined dataset of small- and large-subunit nuclear ribosomal DNA (SSU+LSU nrDNA) was carried out. Tetraplosphaeriaceae, however, is basal to the main pleosporalean clade and therefore its relationship with other existing families was not completely resolved. To evaluate the validity of each taxon and to clarify the phylogenetic relationships within this family, further analyses using sequences from ITS-5.8S nrDNA (ITS), transcription elongation factor 1-α (TEF), and β-tubulin (BT), were also conducted. Monophyly of the family and that of each genus were strongly supported by analyses based on a combined dataset of the three regions (ITS+TEF+BT). Our results also suggest that Tetraplosphaeria (anamorph: Tetraploa s. str.) is an ancestral lineage within this family. Taxonomic placement of the bambusicolous fungi in Astrosphaeriella, Kalmusia, Katumotoa, Massarina, Ophiosphaerella, Phaeosphaeria, Roussoella, Roussoellopsis, and Versicolorisporium, are also discussed based on the SSU+LSU phylogeny.Taxonomic novelties: Tetraplosphaeriaceae Kaz. Tanaka & K. Hiray., fam. nov., Tetraplosphaeria Kaz. Tanaka & K. Hiray., gen. nov., Tetraplosphaeria nagasakiensis Kaz. Tanaka & K. Hiray., sp. nov., Tetraplosphaeria sasicola Kaz. Tanaka & K. Hiray., sp. nov., Tetraplosphaeria tetraploa (Scheuer) Kaz. Tanaka& K. Hiray., comb. nov., Tetraplosphaeria yakushimensis Kaz. Tanaka, K. Hiray. & Hosoya, sp. nov., Triplosphaeria Kaz. Tanaka& K. Hiray., gen. nov., Triplosphaeria acuta Kaz. Tanaka & K. Hiray., sp. nov., Triplosphaeria cylindrica Kaz. Tanaka & K. Hiray., nom. nov., Triplosphaeria maxima Kaz. Tanaka & K. Hiray., sp. nov., Triplosphaeria yezoensis (I. Hino & Katum.) Kaz. Tanaka, K. Hiray. & Shirouzu, comb. nov., Polyplosphaeria Kaz. Tanaka & K. Hiray., gen. nov., Polyplosphaeria fusca Kaz. Tanaka& K. Hiray., sp. nov., Pseudotetraploa Kaz. Tanaka & K. Hiray., gen. nov., Pseudotetraploa curviappendiculata (Sat. Hatak., Kaz. Tanaka & Y. Harada) Kaz. Tanaka & K. Hiray., comb. nov., Pseudotetraploa javanica (Rifai, Zainuddin & Cholil) Kaz. Tanaka& K. Hiray., comb. nov., Pseudotetraploa longissima (Sat. Hatak., Kaz. Tanaka & Y. Harada) Kaz. Tanaka & K. Hiray., comb. nov., Quadricrura Kaz. Tanaka, K. Hiray. & Sat. Hatak., gen. nov., Quadricrura bicornis Kaz. Tanaka, K. Hiray. & H. Yonez., sp. nov., Quadricrura meridionalis Kaz. Tanaka & K. Hiray., sp. nov., Quadricrura septentrionalis Kaz. Tanaka, K. Hiray. & Sat. Hatak., sp. nov
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
Normalized solutions for fractional nonlinear scalar field equations via Lagrangian formulation
Full text linkWe study existence of solutions for the fractional problem (Pm)
(−Δ)su + μu = g(u) in RN,
RN
u2dx = m,
u ∈ Hs
r (RN),
where N 2, s ∈ (0, 1), m > 0, μ is an unknown Lagrange multiplier and
g ∈ C(R,R) satisfies Berestycki–Lions type conditions. Using a Lagrangian
formulation of the problem (Pm), we prove the existence of a weak solution
with prescribed mass when g has L2 subcritical growth. The approach relies on
the construction of a minimax structure, by means of a Pohozaev’s mountain in
a product space and some deformation arguments under a new version of the
Palais–Smale condition introduced in Hirata and Tanaka (2019 Adv. Nonlinear
Stud. 19 263–90); Ikoma and Tanaka (2019 Adv. Differ. Equ. 24 609–46). A
multiplicity result of infinitely many normalized solutions is also obtained if g
is odd
Symmetric Ground States for Doubly Nonlocal Equations with Mass Constraint
No full textWe prove the existence of a spherically symmetric solution for a Schrödinger equation
with a nonlocal nonlinearity of Choquard type. This term is assumed to be subcritical and satisfy
almost optimal assumptions. The mass of of the solution, described by its norm in the Lebesgue
space, is prescribed in advance. The approach to this constrained problem relies on a Lagrange
formulation and new deformation arguments. In addition, we prove that the obtained solution is
also a ground state, which means that it realizes minimal energy among all the possible solutions to
the problem
Periodic solutions with prescribed energy for a class of Keplerian N-body problem
No full textThe paper deals with the existence of periodic solutions of fixed energy for a class of N-body type problems with Keplerian like interaction
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