1,721,004 research outputs found
Betanodavirus ability to infect juvenile European sea bass, Dicentrarchus labrax, at different water salinity
No full textViral encephalopathy and retinopathy (VER) is one of the most devastating and economically relevant diseases for marine aquaculture. The presence of betanodavirus in freshwater fish is recorded, but very little is known about VER outbreaks in marine species reared in freshwater. Our study investigated the ability of betanodavirus to cause disease in European sea bass, Dicentrarchus labrax, reared at different salinity levels. Fish were challenged with RGNNV or mock infected by bath at different salinity levels (freshwater, 25â° and 33â°). Fish were checked twice a day and the dead ones were examined by standard virological techniques, by rRT-PCR and by histochemical and immunohistochemical analyses. All the infected groups showed a significant higher mortality rate than the one of the mock-infected group. VERv presence was confirmed by rRT-PCR. Histochemical and immunohistochemical analyses highlighted the typical lesions associated with VER. Our results highlight that salinity does not affect the ability of betanodavirus to induce clinical signs and mortality in European sea bass infected under experimental conditions. These results underline the great adaptation potential of VERv, which in combination with its already known high environmental resistance and broad host range, may explain the diffusion of this disease and the threat posed to aquaculture worldwide
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
New Challenges and Achievements in Mediterranean Fish Health Management
No full textThe European seabass (Dicentrarchus labrax) and gilthead seabream (Sparus aurata) are key species in marine aquaculture, cultivated in both EU and North African/Levant Mediterranean regions. Production disparities between these areas emphasize a significant reliance on trade for juveniles, feed, and other resources, posing notable biosecurity risks. Addressing shared health concerns across the Mediterranean requires a regional approach to ensure successful management. A recent workshop delved into pivotal topics, including insights from concluded Horizon 2020 projects, effectiveness of nutraceuticals in combating parasitic infections, legal considerations surrounding autogenous vaccines, updated knowledge in betanodavirus infections, and biosecurity measures in Mediterranean aquaculture. Discussions also explored upcoming challenges such as sustainability in cage-based production, impact of climate change, enhancing diagnostic capabilities, fortifying biosecurity measures, advocating for education, and fostering networking opportunities
Immunohistochemical patterns of a non-viral papilloma in goldfish (Carassius auratus, L.)
No full textAn epithelial tumour of the skin is reported in a goldfish (Carassius auratus). Immunohistochemistry showed huge cytoplasmic positivity in tumour cells, confirming the histological diagnosis of papilloma. Although similar neoplasias have been described in fish and have been related to herpesvirus, virological examination was negative in this case
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
Herpesvirus della carpa Koi (KHV): infezione sperimentale e diagnosi di laboratorio. / Koi carp herpesvirus (KHV): experimental infection and laboratory diagnosis.
No full textRIASSUNTO - L’allevamento della carpa, sia a scopo alimentare che ornamentale, rappresenta una delle attività di acquacoltura più diffuse a livello mondiale. La comparsa dell’herpesvirosi della carpa koi, dapprima nelle carpe ornamentali e, più recentemente, nella carpa comune, ha evidenziato l’estrema vulnerabilità della specie Cyprinus carpio nei confronti di questo agente virale emergente, identificato per la prima volta in Israele nel 1998. Da allora la malattia si è diffusa in molte aree geografiche, soprattutto a seguito degli scambi commerciali e manifestazioni hobbistiche delle varietà ornamentali e, nel caso delle varietà destinate al consumo e alla pesca sportiva, attraverso il commercio di partite infette ed i reflui delle aziende contaminate. Inoltre non si può escludere che la malattia si sia diffusa anche per le difficoltà diagnostiche che la caratterizzano.
Nel presente lavoro due gruppi di carpe comuni sono state infettate, per via intramuscolare e per bagno, con il ceppo di referenza KHV UK C250, per riprodurre sperimentalmente la malattia. Sui soggetti morti sono stati applicati diversi protocolli diagnostici: isolamento virale, microscopia elettronica, istologia e PCR per valutarne l’efficacia. I risultati ottenuti nel corso di queste prime indagini confermano che il KHV è un virus di difficile isolamento anche su substrati cellulari ritenuti specifici e che il miglior approccio diagnostico, dovrebbe prevedere il ricorso a più tecniche di laboratorio, in attesa di identificare un metodo d’elezione validato a livello internazionale.
SUMMARY - Carp farming represents the most significant aquaculture activity in the world. At present koi herpesvirus disease (KHVD) is considered to be one of the most risky factors affecting populations of common and koi carp. The first outbreak of the disease was reported in 1998 in Israel, since then several cases have been confirmed all over the world both in wild and reared stocks. Commercial trades are the most important factor in spreading KHV; furthermore the lack of a robust diagnostic method may have certainly contributed to the spreading of the disease.
In this paper two sets of common carps were infected with a laboratory reference KHV strain (UK C250) by intramuscular injection and water bath in order to reproduce the disease and provide reference tissues for diagnostic investigations. Different tests were performed on dead fish: viral isolation, electron microscopy, histology and PCR in order to compare the diagnostic efficacy. Our results confirm the problems to isolate KHV and underline the need of multiple techniques approach to the disease before a gold standard technique is standardized at international level
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
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