1,720,961 research outputs found
IMPACT OF WATER TEMPERATURE ON THE SEA BASS (D. LABRAX) RESPONSIVENESS TO IN FIELD VACCINATION AGAINST VIBRIOSIS/PHOTOBACTERIOSIS
No full textRoutinely sea bass vaccination programs against Vibriosis/Photobacteriosis include the immersion of fish at 1–2 g in aqueous vaccine prior to transportation to floating cages, followed by an intraperitoneal (ip) administration of water-oil based vaccine at 20–25 g, which usually coincides with fish sizing. The most suitable period for the latter treatment would range from spring to summer, considering that the best antibody response both in terms of level and rapidity is detectable in sea bass immunized at 24°C (Cecchini & Saroglia, 2002). Still the time required to vaccinate all the farmed stocks sometimes exceeds the optimal period, and vaccination has to be carried even during winter season. For this reason, the objective of the present investigation was to explore the opportunity to get effective immune responses after a vaccination at sub-optimal temperatures (14°-16°C). The efficacy of the bivalent (Vibrio-Photobacterium) commercial vaccine AlphaJect 2000TM (Pharmaq AS) was assessed in the field (CROMARIS, Mala Lamjana Croatia), by submitting cage reared sea bass (size range 80-145 g) to sedation and ip vaccination (0.1 ml/fish) at different temperature ranges during autumn/winter/summer 2017-2018. Serum sampling was performed in each cage at T0 (intended as pre-vaccination control) and at 500° day post vaccination (this could vary between 32 and 38 days post vaccination, depending on the water T°). Parallel samplings were performed also in cages not submitted to vaccination. In detail, 30 randomly selected individuals/cage/sampling time were submitted to sedation and then sampled in order to obtain the serum. The specific antibodies (IgM) raised against one of the two target antigens (V. anguillarum O1), being part of the formulation, were determined by E.L.I.S.A. accordingly to the protocol of Galeotti et al., (2013). As far as we know there are not information on the vaccination effectiveness in sea bass against bacterial diseases (such as Vibriosis or Photobacteriosis) at different temperatures, and the present investigation represented a preliminary approach to this issue. The specific IgM titration performed on pre-vaccination samples showed their negativity (O.D. values often lower than those recorded in the “blank” wells, or negligible). The i.p. vaccination performed in winter months at temperatures near to 14-16°C triggered a synthesis of specific IgM to V. anguillarum O1 only in a limited number of individuals among those vaccinated, highlighting that there is an evident individual variability in terms of response to vaccination. If we exclude the limited role ascribable to non-appropriate vaccine provision, based on our findings we can assert that there is a relevant difference in the individual “immune efficiency” at low temperatures, possibly limiting the uniformity of fish batches responsiveness after the treatment. On the contrary the ip vaccination performed in summer, at temperatures ranging between 21,4-23,8 (average 22,6) promoted a remarkable synthesis of specific IgM to V. anguillarum O1 in almost all the fish under study, suggesting the requirement of specific (optimal) temperatures enabling fish to benefit from the immunization treatment
Emerging enteric parasitic diseases in farmed gilthead sea bream (Sparus aurata)
No full textIntroduction: Enteric parasites affecting farmed gilthead sea bream (GSB) have become a serious threat for Mediterranean aquaculture in the last few years; among these parasites Enteromyxum leei, Enterospora nucleophila and Cryptosporidium molnari are undoubtedly the most concerning ones. While the enteric myxozoan E. leei has been broadly studied, the available data on the occurrence of E. nucleophila and C. molnari infections are still scarce. Aim of this work was to improve the knowledge about these latter two parasites in Mediterranean aquaculture by carrying out an epidemiological survey in GSB farmed in Italy and Croatia.
Methodology: 308 GSB of which 40 from an Italian hatchery, 174 from three cage farms located in Italy and 94 GSB from one cage farm located in Croatia were tested with qPCR and PCR to assess the presence of E. nucleophila and C. molnari. Histology was also performed on infected GSB.
Results: All the examined farms tested positive for both parasites: 60% of the fish examined from hatchery were positive for E. nucleophila, while 22.5% resulted positive for C. molnari. Concerning caged fish, E. nucleophila was found in 63.2% of the GSB coming from Italian farms and in 45.7% of fish from Croatia. C. molnari was detected in 3.4% of Italian GSB and in 2.1% of the Croatian ones. Histological lesions were consistent with those already reported in literature for these enteric parasitic infections.
Conclusion: This study showed a diffuse presence and a high prevalence of E. nucleophila in Italian and Croatian farmed GSB. Although at lower prevalence, also C. molnari showed to occur in farmed GSB, especially in hatchery and juveniles. Thus, further investigations are required to establish their epidemiology, transmission routes and pathogenic role in farmed GSB along its production cycle in order to assess and manage the risks arousing from these emerging enteric parasites
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
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
A stratified compartmental model for the transmission of Sparicotyle chrysophrii (Platyhelminthes: Monogenea) in gilthead seabream (Sparus aurata) fish farms †
Full text linkThe rapid development of intensive fish farming has been associated with the spreading of infectious diseases, pathogens and parasites. One such parasite is Sparicotyle chrysophrii (Platyhelminthes: Monogenea), which commonly infects cultured gilthead seabream (Sparus aurata)-a vital species in Mediterranean aquaculture. The parasite attaches to fish gills and can cause epizootics in sea cages with relevant consequences for fish health and associated economic losses for fish farmers. In this study, a novel stratified compartmental epidemiological model of S. chrysophrii transmission was developed and analysed. The model accounts for the temporal progression of the number of juvenile and adult parasites attached to each fish, as well as the abundance of eggs and oncomiracidia. We applied the model to data collected in a seabream farm, where the fish population and the number of adult parasites attached to fish gills were closely monitored in six different cages for 10 months. The model successfully replicated the temporal dynamics of the distribution of the parasite abundance within fish hosts and simulated the effects of environmental factors, such as water temperature, on the transmission dynamics. The findings highlight the potential of modelling tools for farming management, aiding in the prevention and control of S. chrysophrii infections in Mediterranean aquaculture
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
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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