1,720,973 research outputs found
TROPICSAFE project: identification and management of phytoplasma-associated diseases in coconut palms in Ghana, Mexico, Jamaica and Cuba ed in grapevine in South Africa, Chile and Italy.
No full textThe TROPICSAFE project covers the diseases associated with phloem limited bacteria associated diseases in coconut palms, grapevine, and citrus species in diverse countries (http://www.tropicsafe.eu/). A part for the citrus “huanglongbing” disease associated with the presence of ‘Candidatus Liberibacter’ species mainly studied in Cuba, France (Guadeloupe), South Africa and Spain where for the moment only one of its insect vectors, Trioza eritreae is present, the project studies the epidemiology and management of coconut palms and grapevine associated phytoplasma diseases. Coconut palm lethal yellowing (LY) is studied in Ghana, Cuba, Jamaica and Mexico and grapevine yellows (GY) are studied in Italy, South Africa, and Chile. The presence and the identity of the pathogen strains present in the different countries was verified through their molecular characterization and in some cases also cultivation in artificial media to acquire the data necessary to detect and manage in sustainable manner the studied diseases. The pathogen identification in alternative host plants and insects vectors and potential vectors was also performed together with the improvement of specific diagnostic techniques.
The confirmation of the presence of 16SrXXII-B and 16SrIV phytoplasmas in Ghana and in the Caribbean (Jamaica, Cuba, and Mexico), respectively, allowed to study alternative plant species and potential insect vectors to define the epidemiological cycles of this disease towards its focused management. In Jamaica where the LY disease has been managed since some time with sustainable results a newly discovered species Oecleus mackaspringii was associated with coconut palm in plots with still active cases of the disease acting as possible insect vector. In Cuba also symptomatic palms positive for phytoplasmas belonging to the ribosomal groups 16SrI, 16SrVII and 16SrXII were identified and citrus with “huanglongbing” symptoms the 16SrIV phytoplasma was found in mixed infection with ‘Ca. L. asiaticus’ or other phytoplasmas. In Mexico transmission trials with Haplaxius crudus confirmed its vector role in this Country. Dwarf coconut varieties showed promising results in relation to LY resistance in Ghana. GY disease are associated in South Africa with ‘Candidatus Phytoplasma asteris’-related strains transmitted by Mgenia fuscovaria, while Chile and in Italy phytoplasmas belonging to diverse ribosomal subgroups, several alternative host plants, and some insect species have been described as phytoplasma vectors or potential vectors in grapevine or in vineyard environments. In Chile the 16SrIII-J phytoplasma is transmitted by Paratanus exitiosus and Bergallia valdiviana. Surveys in selected north Italy vineyards detected ‘Ca. P. solani’, ‘Ca. P. fraxini’, ‘Ca. P. asteris’ and “flavescence dorée” phytoplasmas and new potential insect vectors. It is therefore clear that only a constant monitoring will allow for the prompt detection of phytoplasmas or new phytoplasmas that may infect the studied crops. Appropriate management is linked to the diverse geographical location and agro-ecosystem conditions but with the appropriated epidemiologic knowledge can be applied as sustainable tool to reduce economic losses and the environmental pollution
‘Candidatus Phytoplasma’ and ‘Candidatus Liberibacter’ species detection in citrus
No full text“Huanglongbing” (HLB) is one of the most devastating citrus diseases in the world. Citrus samples with symptoms referable to HLB were collected in different Caribbean Countries to verify the possible association of ‘Candidatus Phytoplasma’ and HLB. In Cuba, 140 samples out of 142, resulted positive for HLB and 32 were positive also for phytoplasmas. In Jamaica, out of 6 samples, 5 were positive to HLB and 1 was positive to phytoplasmas. In Guadeloupe, 17 samples were positive for HLB and 7 for phytoplasmas. These results indicate that the symptomatology is not discriminating between the two pathogens and the mixed infection is not an uncommon event
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
‘Candidatus Phytoplasma’ species detection in coconuts in Cuba
No full textCoconut lethal yellowing (LY) is the single most important disease presently affecting the coconut production worldwide. Symptomatic and asymptomatic coconut plants were sampled in some selected areas to verify the identity of phytoplasmas associated with LY in Cuba. Diverse phytoplasma ribosomal groups were detected in the samples from symptomatic palms such as 16SrXII, 16SrVII, and 16SrI. In several other palms 16SrIV-A subgroup phytoplasmas were identified, in the groEL gene the only positive plant from Pilón resulted diverse from the others and identical to the 16SrIV-A strains detected in Jamaica LY infected coconut palms. This is the first record of occurrence of 16SrI, -VII and -XII groups in coconut palms in Cuba
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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