1,720,992 research outputs found
Interaction of probiotic bacteria with commensal bacteria : an overview
No full textThe gastrointestinal tract of humans and animals is divided into sections that have different functions (Figure 3.1). The different regions of the gastrointestinal tract represent very different environments for the bacteria inhabiting the gut. These different regions are characterized by differences in pH, secretion of enzymes, moisture, temperature and presence or absence of villi on the intestinal surface. It is now known that different species of bacteria reside in different regions of the gut, and a species occupies a particular region in order to meet its nutritional and environmental requirements (Ewing and Cole, 1994). The bacterial flora of the GIT represents an ecosystem of high complexity, the understanding of which is very limited (Berg, 1996)
Overall conclusions and future directions
No full textThe aim of this book was to address the following issues:
I. To investigate E. coli diversity in the porcine GIT in order to assess whether faecal isolates are representative of those found elsewhere in the gut and therefore provide better understanding of interactions that may be taking place between probiotic bacteria and commensal strains and pathogenic strains found in different regions of the gut.
2. To optimize a method that would enable assessment of bacterial strains for their ability to inhibit growth of bacterial pathogens in vitro, thereby providing a tool to compare the efficacy of inhibition by various Gram-positive probiotic strains.
3. To assess the ability of colicin producer Gram-negative E. coli strains to inhibit growth of other Gram-negative and Gram-positive pathogens so that the producer strains may be further scrutinized for their probiotic properties
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Introduction to probiotic bacteria
No full textEver since Alexander Fleming discovered the antibacterial properties of the fungus Penicillium spp. in 1929 (Fleming, 1929), the world has seen a rapid dominance of antibiotics in the treatment of various diseases. The development of broad spectrum and highly specific antibiotics has led to medical science relying heavily on antibiotics as therapeutic agents against different pathogens. There is however certain drawbacks associated with antibiotic therapies. The eliminating action of antibodies does not discriminate between pathogens and the beneficial intestinal microflora. Consequently, an antibiotic therapy also results in an altered intestinal balance causing a number of unpleasant side effects that can persist long after the cessation of treatment. The fast emergence of multiple antibiotic resistant populations of bacteria such as vancomycin- resistant enterococci and methicillin resistant Staphylococcus aureus in hospital environments is also a growing concern among the medical practitioners. Furthermore, some infections once thought readily treatable with antibiotics are now being recognised as serious health threats. For example, a diarrhoeal disease can result from Clostridium difjicile, an opportunistic pathogen, due to the disruption of the normal intestinal microflora during antibiotic treatment. Although this disease is generally treated successfully with a second antibiotic some infections however recur in spite of the antibiotic therapy (Sanders, 1999). Consequently, people all over the world are recognising that preventing or reducing the risk of a disease is preferable to treating diseases. The World Health Organisation recommends global programs to reduce the use of antibiotics in human medicine and suggests increased efforts to prevent diseases through the development of more effective and safer vaccines (Stanton et. al., 2001). A climate has thus been initiated wherein both doctors and patients are searching for preventive rather than curative approaches to diseases in which the intestinal microflora is not adversely affected. One such approach that has rapidly gained popularity is the concept and recognition of probiotics, a general term for nutritional supplements containing one or more cultures of living organisms (typically bacteria or yeast) that, when introduced to a human have a beneficial impact on the host by improving the endogenous microflora (Markowitz and Bengmark, 2002). As compared to the invasive, costly and chemical properties of antibiotics, probiotics scores by being non-invasive, safe, natural, and mostly free of any unpleasant side effects. In recent decades there has been an increase in the prevalence of diseases linked to changes in environmental factors and linking to gut microbiota, providing a rationale for an increased use of probiotics, which can shape the host's immune response
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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