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Doğal olarak aflatoksin ile kontamine olmuş yerfıstığı küspesinin rhodococcus erythropolıs kullanılarak mikrobiyal detoksifikasyonu.
No full textAflatoxins are highly mutagenic toxins with carcinogenic effects produced as secondary metabolites by fungal species Aspergillus flavus and Aspergillus parasiticus under certain conditions. Chronic or acute consumption of aflatoxins found in food and feed products possesses great health risks. It is particularly an important problem in animal feed from food waste and by-products. Therefore there is growing need to eliminate aflatoxins from contaminated products. In this study, first the optimum growth conditions of gram-positive, aerobic bacterium Rhodococcus erythropolis, which is known to be degrading aflatoxin, were determined in synthetic media. One factor at a time approach was adopted to determine the most effective carbon and nitrogen sources for growth. Plackett Burman design was used to screen other variables (temperature, pH, liquid culture volume, agitation speed and concentrations of nitrogen and carbon sources) vi important for growth. Three variables determined as significant by Plackett-Burman design was then further evaluated with Box-Behnken response surface optimization method and optimum conditions were defined for growth of R. erythropolis. For better understanding of aflatoxin degrading ability of R. erythropolis, viable cells and crude extracellular enzymes were compared. Process conditions for detoxification of Aflatoxin B1 were optimized by Box-Behnken response surface method with three variables (solid concentration, inoculum volume and time). Decrease in toxicity of treated groundnut meal was assessed by sheep liver glutathione-S-transferase (GST) assay. The results showed that peptone and glucose are the best nitrogen and carbon sources for growth of R. erythropolis, respectively. Optimal culture conditions were found as 22.5 °C of temperature, pH 7, 100 mL of liquid volume in 500 mL flasks, 1% (v/v) of inoculum volume, 135 rpm of agitation speed, 5 g/L of glucose concentration and 5 g/L of peptone concentration. Viable cells were found to be more effective for Aflatoxin B1 degradation and used for rest of the study. It was observed that R. erythropolis cells and extracellular enzymes are able to degrade aflatoxin even when grown in absence of the toxin. It was observed that viable cell cultures of R. erythropolis performed better detoxification activity than extracellular enzymes. Optimum conditions for detoxification were found as 27.4 %(w/v) of solid concentration, 4.88 %(v/v) of inoculum volume and 24 h of time by Box-Behnken response optimization. At these conditions maximum reduction in AFB1 was predicted as 92.2% and verified as 87.3% Toxicity of treated groundnut meal extracts were found to be decreased significanty by GST assay. Treated samples inhibited the enzyme activity 64.5% and untreated samples inhibited 86.6%. As a result, viable cell cultures of R. erythropolis was suggested as an effective detoxification agent for aflatoxin contaminated groundnut meal used for animal feed.M.S. - Master of Scienc
Co-production of pectinase, xylanase and cellulase complex using Bacillus subtilis grown on food processing wastes
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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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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