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Mrakia fibulata sp. nov., a psychrotolerant yeast from temperate and cold habitats
No full textTree fluxes are sugar-rich, sometimes
ephemeral, substrates occurring on sites where tree
sap (xylem or phloem) is leaking through damages of
tree bark. Tree sap infested with microorganisms has
been the source of isolation of many species, including
the biotechnologically relevant carotenoid yeast Phaffia
rhodozyma. Tree fluxes recently sampled in
Germany yielded 19 species, including several psychrophilic
yeasts of the genus Mrakia. Four strains
from tree fluxes represented a potential novel Mrakia
species previously known from two isolates from
superficial glacial melting water of Calderone Glacier
(Italy). The Italian isolates, originally identified as
Mrakia aquatica, and two strains from Germany did
not show any sexual structures. But another culture
collected in Germany produced clamped hyphae with
teliospores. A detailed examination of the five isolates
(three from Germany and two from Italy) proved them
to be a novel yeast species, which is described in this
manuscript as Mrakia fibulata sp. nov. (MB 830398),
holotype DSM 103931 and isotype DBVPG 8059. In
contrast to other sexually reproducing Mrakia species,
M. fibulata produces true hyphae with clamp connections.
Also, this is the first psychrotolerant Mrakia
species which grows above 20 C. Spring tree fluxes
are widespread and can be recognized and sampled by
amateurs in a Citizen Science project. This substrate is
a prominent source of yeasts, and may harbor
unknown species, as demonstrated in the present
work. The description of Mrakia fibulata is dedicated
to our volunteer helpers and amateurs, like Anna
Yurkova (9-years-old daughter of Andrey Yurkov),
who collected the sample which yielded the type strain
of this species
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
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Antagonistic actions of prostaglandins E2 and F2 alpha on the isolated lungs of the frog, Rana esculenta L.
Full text link1. Isolated lungs of the frog, Rana esculenta L., when incubated in amphibian Ringer solution for 30 min, produced a prostaglandin E2-like substance (27.1 ± 3.8 ng/g w.w.), as determined by bioassay on the isolated rat stomach strip. 2. The release of PGE2-like substance from skin, heart and bowel is also reported. 3. The activity of synthetic prostaglandins E2 (PGE2) and F2alpha (PGF2alpha) on the muscular contractility of frog isolated lungs was investigated: PGE2 and PGF2alpha relaxed and contracted respectively in a dose-dependent manner this preparation, a result similar to that obtained in mammals
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
Filamentous Fungi transported by birds during migration across the mediterranean Sea.
Full text linkThe potential for the transport and diffusion of
some pathogenic microorganisms by migratory birds is of
concern. Migratory birds may be involved in the dispersal of
microorganisms and may play a role of mechanical and
biological vectors. The efficiency of dispersal of pathogenic
microorganisms depends on a wide range of biotic and
abiotic factors that influence the survival or disappearance
of a given agent in a geographical area. In the present study,
349 migratory birds were captured in four sites (Mazara del
Vallo, Lampedusa, Ustica and Linosa), representing the
main stop-over points during spring and autumnal migration,
and analyzed for the presence of filamentous fungi. A
total of 2,337 filamentous fungi were isolated from 216
birds and identified by a combined phenotypic-genotypic
approach to species level. Twelve species were identified in
the study, with Cladosporium cladosporioides, Alternaria
alternata, and Aspergillus niger as the most abundant. The
transport of these fungal species isolated in this study is of
considerable importance because some of these species can
create dangers to human health
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