1,721,128 research outputs found
Detection of three closteroviruses in stone fruit trees by multiplex assays
No full textSimultaneous detection of Plum bark necrosis stem pitting-
associated virus (PBNSPaV), Little cherry virus 1
(LChV-1) and Little cherry virus 2 (LChV-2) was
achieved with a quadruplex one-step RT-PCR, and a hybridization
test with a multi-riboprobe, apparently representing
the first successful attempt of concomitant identification
of viruses of the family Closteroviridae in stone
fruit trees. Quadruplex RT-PCR detected double (natural
and artificial) and triple (artificial) infections in all samples
tested, amplifying also a plant mRNA as an internal
control. Standard and quadruplex RT-PCR were comparable
in terms of detection limits and specificity. Molecular
hybridization with a multi-riboprobe (‘clotri’) containing
partial sequences of PBNSPaV, LChV-1 and LChV-2,
allowed the detection of each of the three viruses in
Prunus hosts. The sensitivity of single riboprobes and
“clotri” was comparable
First report of Little cherry virus 1 in cherry, plum, almond and peach in Italy
No full textLittle cherry disease (LChD) is a widespread disorder of
ornamental, sweet and sour cherries. In sensitive cultivars,
it results in the production of small, pale-coloured fruits
with reduced sugar content and in the premature reddening
or bronzing of the leaves. Little cherry virus-1 (LChV-
1) and Little cherry virus 2 (LChV-2), both members of the
family Closteroviridae, are associated with this disease, but
often induce symptomless infection. Assays for both viruses
were made during a survey in 2006 and 2007 of the sanitary
status of fruit trees in Apulia (southern Italy). Samples
were collected in different commercial orchards from 22
sweet cherry, 13 plum, five almond, five peach, and two
apricot trees. Total nucleic acids (TNA) were extracted
from the leaves as described by Foissac et al. (2001) and
used as template for Superscript III one-step RT-PCR with
Platinum Taq DNA polymerase (Invitrogen, Carlsbad, CA,
USA) using primer sets specific for LChV-1 or LChV-2
(Rott and Jelkmann, 2001). Whereas all samples were negative
for LChV-2, a 419 bp fragment corresponding to part
of the 3' non-translated region of LChV-1 RNA was amplified
from five cherry, four plum, one almond and one
peach tree samples. These results were obtained in several
independent experiments. Trees of both native and imported
cultivars were infected but LChV-1 was not associated
with any particular field symptoms. To our knowledge,
this is the first report of LChV-1 in Italy and of its
natural occurrence in plum, almond and peach
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
Detection of Plum bark necrosis stem pitting-associated virus (PBNSPaV) from different stone fruit species and optimisation of diagnostic tools.
No full text
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
Monitoring of Plum bark necrosis stem pitting-associated virus and molecular characterization of some isolates
No full textDifferent Prunus species from Italy, Serbia, Turkey
and Egypt were assayed by one-step RT-PCR and nested
PCR for the presence of Plum bark necrosis stem pittingassociated
virus (PBNSPaV). This virus had a fairly high
incidence and was monitored throughout the year by
IC-RT-PCR and ELISA. It was detected during all seasons
by both techniques but most easily in spring in the
new flushes of vegetation. Six PBNSPaV isolates were
characterized by partial sequencing of three genomic regions,
e.g. HSP70, coat protein and ORF4. High nucleotide
similarity was found between all isolates from
different geographic and host origins, suggesting either
a relatively recent origin or the presence of unidentified
constraint on variation
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