1,720,957 research outputs found
Molecular analysis of host cells response against infection of virulent strains Listeria monocytogenes / Maimunah Mustakim, Zuraini Mat Issa and Prof Dr Son Radu
Full text linkListeria monocytogenes is a foodborne pathogenic bacteria causing severe systemic infection in susceptible individuals. This facultative intracellular pathogen infects host tissues using their flagella actin. Listeria monocytogenes propelled from one cell to another through the assembly of the flagella actin with the host cells.The present study aims to examine the rearrangement of host cells cytoskeleton actin upon infection of Listeria monocytogenes. Human colon carcinoma (HCT 116) cell lines were infected with Listeria monocytogenes strains. Cells were stained withalexa fluor 635 phalloidin prior to observation by confocal laser scanning microscopy (CLSM) to examine cellular changes of the host cells upon infection with the bacteria. The infected cells showed actin rearrangement from filamentous network to aggregation features. The infected cells also showed reduced membrane ruffling. The present study demonstrated interaction of host cells actin with Listeria monocytogenes. Confocal laser scanning microscope (CLSM) examination revealed the cytoskeleton actin rearrangement in the infected host cells
Characterization of Listeria monocytogenes isolated from foods / Zuraini Mat Issa, Maimunah Mustakim and Son Radu
Full text linkListeria monocytogenes is one of the major food-borne pathogen with an opportunistic character that is able to cause severe human listeriosis worldwide. The development of a surveillance and detection system concerning food safety in this country needs to be improved. Therefore, this study was conducted to provide a general baseline on the contamination of L. monocytogenes in various foods in the local markets in Selangor. A total of 140 raw and ready-to-eat food samples were analyzed by plating on selective PALCAM medium and the suspected L. monocytogenes colonies were confirmed at molecular level by MPN-PCR technique using primers specific for this food-borne pathogen. All of the 23 isolated strains yield a PCR product of 938 bp and 701 bp for 16s rRNA gene and hylA virulence gene respectively. The confirmed isolates were characterized for their intra-species discrimination according to reaction between antigen-antisera by serotyping technique and patterns generated by RAPD bands. Two screened RAPD primers demonstrating potentially useful banding patterns were selected and examined against L monocytogenes isolates. Positive isolates were evaluated for their susceptibility to eight commonly used antibiotic agents by using disc diffusion assay. L monocytogenes was detected in 8.57% of collected food samples which 33.3%, 25% and 13.3% were detected in burger, minced meat and sausage samples respectively. The highest resistances (100%) of L monocytogenes isolates were demonstrated against ampicillin and penicillin G antibiotics, whereas high susceptibility was showed toward streptomycin (100%). The molecular approaches used in this study provide highly sensitive and specific results which were very easy and fast to perform. These findings also suggested that the contamination of L monocytogenes in foods is relatively low. However, it highlighted the emergence of antibiotics multi-resistant Listeria in the present environment
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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