1,720,956 research outputs found
First Report of Philometroides sanguineus (Nematoda: Philometridae) in Farmed Goldfish (Carassius auratus) in Italy
No full textThe ornamental fish trade has facilitated the global dissemination of parasites, posing significant biosecurity risks. This study documents the first detection of the nematode Philometroides sanguineus in farmed goldfish (Carassius auratus) in Emilia-Romagna, Italy. Specimens of gravid females, found in the caudal fins, and males, collected from the swim bladder, were identified through morphological, molecular and scanning electron microscope (SEM) analyses. This report underscores the risk of nonnative pathogen introduction via ornamental fish translocation, and the possibility of their spreading through the aquatic environment. In fact, the role of intermediate hosts, such as copepods, in parasite dissemination emphasises the need for stricter controls in systems reliant on surface water. Although P. sanguineus infection did not cause significant mortality in adult fish, its presence diminishes the ornamental value of infected specimens and raises concerns about the parasite's spread to native ecosystems. This case highlights the need to improve the biosecurity measures and comprehensive risk assessments to mitigate the introduction and propagation of alien parasites in aquaculture systems. Further research is necessary to evaluate the parasite's epidemiology, distribution and potential pathogenicity under different environmental and farming conditions
Unidentified intracellular bacteria causing severe disease outbreak in farmed gilthead sea bream (Sparus aurata).
No full textINTRODUCTION
Mediterranean mariculture is increasingly challenged by emerging transmissible diseases, primarily caused by pathogenic bacteria such as Lactococccus garvieae, Aeromonas veronii and Rickettsia-like organisms (RLO) among others. This report describes the diagnostic process undertaken to identify the etiological agent responsible for a severe mortality outbreak in gilthead sea bream (Sparus aurata) farmed in the Mediterranean. In March 2025, an outbreak occurred in a pre-growing sector of an inland facility, affecting juveniles with an average weight of 1-10 g.
Affected fish exhibited nonspecific clinical signs such as lethargy and disorexia, followed by the appearance of whitish patches on the skin over the lateral musculature. These lesions progressed into erosive/ulcerative wounds and eventually
into widespread proliferative skin alterations. Cumulative mortality reached nearly 100% in some tanks, while adjacent tanks showed either no mortality or only minimal losses. The outbreak was successfully managed with Florfenicol.
METHODOLOGY
Fish were sampled from tanks with the highest mortality and submitted to the involved diagnostic labs as properly refrigerated fresh samples and specimens fixed in 10% neutral buffered formalin for histopathological evaluation. Histological slides were stained with hematoxylin and eosin, Gram stain, and Giemsa stain. All fresh samples underwent parasitological and bacteriological examination according to standard diagnostic procedures. Additionally, skin samples from affected fish were frozen at -20°C and then subjected to molecular analyses.
RESULTS AND DISCUSSION
Both parasitological and bacteriological examinations yielded negative results.
Histological analysis revealed demarcated areas of ulceration of the body walls at various stages of progression, characterized by a marked lymphohistiocytic infiltrate. Along with mixed extracellular bacterial clusters, mainly located on the surface of ulcerated lesions, numerous Gram-negative, intracellular spheroidal bodies were consistently detected within the affected body walls in all fish and interpreted as intracellular bacteria. However, molecular assays targeting RLOs were negative
Outbreaks involving intracellular bacteria with similar clinical features have been previously reported in European sea bass (Dicentrarchus labrax) by Athanassopoulou et al. (1998). Although the histological findings suggested a severe infection by intracellular bacteria morphologically consistent with RLO, the lack of molecular confirmation indicate that the causative agent of the disease may belong to a different taxonomic group. Further investigations are required to identify these enigmatic microorganisms with the goal of implementing effective prevention and control strategies to reduce the risk of future outbreaks.
Athanassopoulou et al., 1999: First incidence of Rickettsia-like infections in cultured sea bass (D. labrax). In: Proceedings 9th International EAFP Conference, Rhodes, Greece
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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