125,272 research outputs found
Biology and management of freesia flower specking caused by Botrytis cinerea
No full textThere is no published research regarding postharvest infection of freesia flowers
by Botrytis cinerea. Although, infection problems have concerned freesia growers and
wholesalers in recent years. The overall objectives of this study were firstly to evaluate
the factors affecting B. cinerea postharvest disease establishment and secondly to
evaluate a range of novel potential treatments to reduce postharvest freesia infection.
These treatment options include plant activators such as acibenzolar-S-methyl and methyl
jasmonate and biotic (Aureobasidium pullulans) and abiotic (UV-C irradiation)
biological/elicitors agents.
Research was undertaken in an attempt to explain the variation in B. cinerea
incidence on cut freesia flowers as noted by the UK importer Zwetsloots & Sons Ltd. in
2000. Higher monthly rejections of freesia flower stems throughout 2000 due to B.
cinerea infection were recorded during spring (April-May), early summer (June) and
autumn (October). Comparatively higher proportions of rejected freesia stems were
associated with glasshouse temperatures ranging from 13-17°C.
In the presence of B. cinerea inoculum on freesia petal surface, temperature was
not a limiting factor for disease establishment. Incubation of artificially inoculated
freesia flowers at 12°C resulted in overall higher disease severity and lesion numbers
compared to flowers incubated at 5 or 20°C. In contrast, relative humidity was the most
important factor for postharvest infection by B. cinerea.
Elicitor based strategies for IPM using the potent activator acibenzolar provided
limited protection of freesia flowers against B. cinerea when applied postharvest.
Acibenzolar significantly reduced disease severity, lesion numbers and lesion diameters
compared to the untreated control when applied at 0.15 g A. 1. U1.
Methyl jasmonate (MeJA) applied as gas, pulse and spray generally suppressed B.
cinerea disease on cut freesia flowers. Disease severity, lesion numbers and lesion
diameters of flowers gassed with 0.1 μL MeJA L"' were reduced by 56,43 and 37%,
respectively compared to untreated control flowers. Gaseous MeJA treated freesia
flowers at 0.1 μL L"1 increased PPO activity by 57% compared to untreated controls 24h
after MeJA treatment. After 36h of incubation at 20°C, disease severity, lesion numbers and lesion diameters of gaseous MeJA treated flowers were reduced by 68,56 and 50%,
respectively, compared to the untreated controls. However, PAL activity in MeJA treated
freesia flowers did not decrease significantly over time compared to untreated control 12h
post-inoculation and thereafter. These findings suggest that MeJA treatment might
suppress the action of PAL in the phenylpropanoid pathway and consequently block SA
production.
UV-C irradiation might be used in an integrated postharvest disease management
program for freesia flowers. UV-C irradiation after artificial inoculation resulted in
markedly reduced B. cinerea disease severity scores and lesion numbers. In detail, UV-C
irradiation of cut freesia flowers with 0.5,1,2.5 and 5 kJ m''` reduced disease severity by
up to 44,70,74 and 59% and lesion numbers by up to 37,62,68 and 60%, respectively.
UV-C irradiation at 1 kJ M-2 before artificial inoculation slightly reduced disease severity
and lesion numbers possibly by inducing defence responses. However, the limited
disease suppression suggested that apparently B. cinerea could overcome the UV-C
induced effect.
The effect of preharvest treatments on freesia crops with acibenzolar was
investigated in glasshouse trials in view to suppress postharvest B. cinerea infection via
SAR induction. Acibenzolar was effective in selected treatments and conditions.
Disease pressure varied over the 3 years and over varieties tested. However, it was
unclear whether acibenzolar induced systemic and/or local defence responses. The latter
was supported by biochemical investigations in 2001 which suggested that acibenzolar
did not induce PAL activity.
In contrast, preharvest MeJA treatment resulted in markedly systemic protection
of treated flowers compared to untreated ones. MeJA efficacy was dependent on variety
and on postharvest incubation temperatures. Disease severity, lesion numbers and lesion
diameters on MeJA treated freesia var. `Dukaat' flowers incubated at 20°C were reduced
by 56,61, and 49% compared to controls, respectively. Also, disease severity, lesion
numbers and lesion diameters on MeJA treated `Cote d'Azur' flowers incubated at 20°C
were reduced by 36,26, and 49% compared to controls, respectively
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Les trains, 1ère classe, 2ème classe..., de la 6ème à la 4ème. Typologie des textes et des discours
No full textBrassart Dominique-Guy, Cauterman M. M., Darras Francine, Delcambre Isabelle, Graczyk B. Les trains, 1ère classe, 2ème classe..., de la 6ème à la 4ème. Typologie des textes et des discours. In: Repères pour la rénovation de l'enseignement du français, n°69, 1986. Communiquer et expliquer au collège, sous la direction de Jean-François Halté. pp. 87-105
Pragmatic Case Studies as a Source of Unity in Applied Psychology
No full textTo unify or not to unify applied psychology: that is the question. In this article we review pendulum swings in the historical efforts to answer this question—from a comprehensive, positivist, “top-down,” deductive yes between the 1930s and the early 60s, to a postmodern no since then. A rationale and proposal for a limited, “bottom-up,” inductive yes in applied psychology is then presented, employing a case-based paradigm that integrates both positivist and postmodern themes and components. This paradigm is labeled “pragmatic psychology” and, its specific use of case studies, the “Pragmatic Case Study Method” (“PCS Method”). We call for the creation of peer-reviewed journal-databases of pragmatic case studies as a foundational source of unifying applied knowledge in our discipline. As one example, the potential of the PCS Method for unifying different angles of theoretical regard is illustrated in an area of applied psychology, psychotherapy, via the case of Mrs. B. The article then turns to the broader historical and epistemological arguments for the unifying nature of the PCS Method in both applied and basic psychology.Peer reviewe
"La première cigarette, tu m'expliques !"
No full textDelcambre Isabelle, Brassart Dominique-Guy, Darras Francine, Graczyk B., Gruwez Claudine, Cauterman M. M., Constant Marylène. "La première cigarette, tu m'expliques !". In: Repères pour la rénovation de l'enseignement du français, n°72, 1987. Discours explicatifs en classe : quand? comment? pourquoi? sous la direction de Jean-François Halté. pp. 81-92
Dr. Edwin Wright Collection: Author Unknown
No full textNotes - The author relates several short stories about his neighbours including Alex McDonell, homesteading and life around Meanook and Athabasca (1 page
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
Measurement of the ratio of branching fractions B(B0→K∗0γ )/B(B0s→φγ ) and the directCP asymmetry inB 0→K∗0γ
No full textThe ratio of branching fractions of the radiative B decays B0→K⁎0γ and B0s→ϕγ has been measured using an integrated luminosity of 1.0 fb−1 of pp collision data collected by the LHCb experiment at a centre-of-mass energy of s√=7TeV. The value obtained is
B(B0→K⁎0γ)B(B0s→ϕγ)=1.23±0.06(stat.)±0.04(syst.)±0.10(fs/fd),
where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions fs/fd. Using the world average value for B(B0→K⁎0γ), the branching fraction B(B0s→ϕγ) is measured to be (3.5±0.4)×10−5.
The direct CP asymmetry in B0→K⁎0γ decays has also been measured with the same data and found to be
ACP(B0→K⁎0γ)=(0.8±1.7(stat.)±0.9(syst.))%.
Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations
The construction of Karen Karnak: The multi-author-function
No full textThis thesis is situated within the comparatively recent developments of Web 2.0 and the emergence of interactive WikiMedia, and explores the mode of authorship within a Read/Write culture compared to that of a Read/Only tradition. The hypothesis of this study is that the role of the audience has become merged with the author, and as such, represents new functions and attributes, distinct from a more conventional concept of authorship, in which the roles of audience and author are more separate. Read/Write and participatory culture, as defined by this study, is focused on collaboration, and includes the influences of D.I.Y. culture, Open-Source practices and the production of text by multiple authors. Multi-authorship presents a re-thinking of several concepts which support the notion of the individual author, since the focus of multi-authorship is not on attribution and ownership of a finished text, but on the continued malleability of a text. Modes of multi-authorship, demonstrated in the use of the pseudonyms Alan Smithee and Karen Eliot, represent declarative authors whose names signify multiple origins, whilst concurrently indicating a distinct body of work. The function of these names form an important context to this study, since primary research involves the construction of an experimental mode of multi-authorship utilising WikiMedia technology and the interaction of thirty nine participants, who are invited to create a body of work under the collective pseudonym Karen Karnak. The data generated by this experiment is analysed using aspects of Michel Foucault's author-function to identify and determine power structures inherent in the WikiMedia context. The interplay of power structures, including concepts such as identity, ownership and the body of work, affect the resulting mode of authorship and contribute to the construction of Karen Karnak, suggesting further areas of research into the emerging multi-author
- …
