1,720,960 research outputs found
Screening of probiotics from indigenous Omani natural products for potential use in the aquaculture industry
Full text linkProbiotics can enhance the growth performance and disease resistance of aquatic animals. Probiotics can influence digestive physiology through the secretion of exogenous digestive enzymes, facilitating the utilization of nutrients, and resulting in improvements in growth performance. The objectives of the present study were to reduce fish diseases, minimize the usage of antibiotics, and promote national policy on aquatic health management in Oman through enhancing immune stimulation mechanisms with probiotics from indigenous Omani products and finally to promote Oman’s aquaculture industry. Thirty-five kinds of edible products were screened. After the primary screening process, only 3 products contained appropriate amounts of probiotics, therefore the present study focused on 3 probiotics from Omani products, i.e., dried date, date vinegar, and camel milk. Gram staining, VITIK2, and DNA tests were used for the identification and characterization of bacterial strains. DNA sequence revealed that the bacteria isolated from dried dates were identified as Bacillus licheniformis. Those from date vinegar were identified as Bacillus vallismortis. A viability test with pepsin, pH 3 showed that the bacteria isolated from camel's milk (Bacillus stratospheric) had a greater tolerance at low pH followed by bacteria isolated from dried date (B. licheniformis). Thus, these can be used as a probiotic for aquatic organisms
Histological Examination of Various Organs of Asian Seabass, Lates calcarifer after an Oral Inactivated Vaccine against Vibrio harveyi
Full text linkDisease outbreaks and consequential losses are a challenge to the aquaculture industry. Diseases in aquaculture are caused by pathogenic agencies, such as bacteria, viruses, and parasites. The use of vaccines is one approach for the control of infections in fish and in building immunity against them. The goal of the present study was to create an effective oral vaccination against V. harveyi in order to ensure the long-term viability of aquaculture operations in the Sultanate of Oman. At a commercial farm, the target bacterium was isolated from infected fish and identified from a pure strain. Bacteria were killed with formalin and cleaned with saline several times. The vaccine was mixed with commercial feed to provide an oral vaccination for fish. This vaccinated feed was given for four weeks, and the efficiency of vaccine was determined by a challenge test, which involved injecting live same species of bacteria into healthy fish. Histology samples were taken when the experiment was completed. Multivitamins and vaccination therapy helped the fish to develop faster and to survive for extended periods of time without any organ damages. The control fish, on the other hand, demonstrated an incapacity to resist bacteria and died as a result, with external and internal organ damage. Despite the positive findings of this study, more research is required
Ectoparasite Fauna of Imported Ornamental Fishes in Oman
Full text linkThe movement of live aquatic animals crossing international borders is a regular activity for economic, social, and public resource development. A survey was carried out to investigate the prevalence of parasites translocated with imported ornamental fishes. Exotic diseases from imported fish have a potential hazard of biosecurity. A sample of 138 imported ornamental fish originating from Thailand and Sri Lanka were collected from pet shops around Muscat governorate and examined for ectoparasites. Parasitological examination was based on a visual macro and microscopic examination of fish’s exterior. The findings of the current survey of imported ornamental fish revealed that 50.72% of the imported ornamental fish were infected by the one or more of ectoparasites species including Ichthyophthirius multifiliis, Dactylogyrus sp., Gyrodactylus sp., digenean metacercaria and Trichodina sp. Parasitic infection of the gills (55.795) was higher than the skin (42.75%). The most prevalent parasite in skin infection was Gyrodactylus sp. (14.49%) but this was absent from the gills which was dominated by digenean metacercaria (26.08%). The existence of such parasitic organisms could pose a threat to native fish populations and the aquaculture sector. It is recommended that a risk analysis method based on the detection and assessment of fish diseases found in live ornamental fish be established and used. Also, exotic pathogenic parasites, as well as their hosts, must be closely monitored to reduce the likelihood of infections being introduced into new areas
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
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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