1,720,962 research outputs found

    Identification and characterization of actinomycetes for biological control of bacterial wilt of Ralstonia solanacearum isolated from tomato

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    Five actinomycetes which showed antimicrobial activity towards Ralstonia solanacearum were identified using specific polymerase chain reaction (PCR) of 16S rDNA gene. Strain C1 and Strain G10 were identified as Streptomyces aureofaciens and S. roseoflavus respectively. All actinomycetes were then characterized using antimicrobial and extracellular enzyme activity, metabolic and restriction fragment length polymorphism (RFLP) profiles. Strain A3 showed positive reaction to three bacteria namely Xanthomonas campestris, Staphylococcus aureus and Listeria monocytogenes. Strain C1 and Strain I15 showed positive reaction towards S. aureus and X. campestris respectively. Strains A3, C1 and I15 were able to metabolize xylan and cellulose, while Strain G10 and Strain L8 were able to use all substrates (xylan, mannan and cellulose) as carbon sources. All the Streptomyces strains were positive towards more than 25 carbon sources and can be differentiated into five distinct strains. These results were consistent and confirmed with DNA analysis of RFLP profiles. The specific amplification of 16S rDNA PCR restriction profiles for the strains using three restriction endonucleases, resulted two restriction profiles produced from the digested 16S rDNA product using HaeIII (H1-H2) and HinfI (Hf1-Hf2), while PstI produced three restriction profiles (P1-P3). No profiles were produced from restriction endonuclases of XbaI, SpeI and BamHI

    Halal market surveillance of soft and hard gel capsules in pharmaceutical products using PCR and southern-hybridization on the biochip analysis

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    The study was conducted to detect the porcine DNA in pharmaceutical products in local market using polymerase chain reaction (PCR) and southern-hybridization on the biochip. A total of 113 (n=113) of hard (82 samples) and soft gel (31 samples) capsules from pharmaceutical products were purchased and tested for the presence of porcine DNA for Halal authentication. All capsules were gelatin-based purchased from local over the counter (OTC) markets. Of all samples tested, 37.2% (42/113) contained porcine DNA. While, none porcine DNA band was detected for 62.8% (71/113) of capsules tested. All samples which were positive toward porcine DNA were imported pharmaceutical products with none Halal logo. Results in the presence study demonstrated that the PCR techniques and southern-hybridization on the biochip is suitable tool for monitoring the Haram component in highly processed product of soft and hard capsule

    Typing of Erwinia chrysanthemi isolated from josapine pineapple in Malaysia using antimicrobial susceptibility, plasmid profiles, ERIC-PCR and RFLP analysis

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    Ninety one leaf samples of Josapine pineapple cultivar (Kelantan, n=8Pahang, n=20Perak, n=11Sabah, n=15Johor, n=37) showing symptoms of heart rot disease were collected to determine the incidence of Erwinia chrysanthemi. Sixteen strains of E. chrysanthemi were isolated from 13 leaf samples from Pahang (n=4), Sabah (n=2) and Johor (n=7). All of the E. chrysanthemi strains displayed resistance to bacitracin with two strains showing resistance to sulfamethoxazole. None of the E. chrysanthemi strains were resistant toward ampicillin, carbenicillin, cephalothin, ceftriaxone, cefuroxime, gentamicin, kanamycin, nalidixic acid, penicillin G, streptomycin and tetracycline. All of the E. chrysanthemi strains were plasmidless. The dendrogram generated from the ERIC-PCR fingerprinting showed that the E. chrysanthemi strains formed 4 clusters and 7 single isolates at 80% similarity level. The restriction fragment length polymorphism (RFLP) analysis for 16 strains of E. chrysanthemi with HinfI and HaeIII endonuclease, 2 and 4 restriction profiles were obtained, respectively. The combinations of the four techniques were able to differentiate the 16 E. chrysanthemi strains into 14 genome types, suggesting a wide diversity of strains examined. ERICPCR fingerprinting method is found to be more discriminating and useful for the determination of the E. chrysanthemi strains relatedness

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

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    We 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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