1,721,068 research outputs found
Helicobacter pylori: A foodborne pathogen?
Helicobacter pylori (H. pylori) is an organism that is widespread in the human population and is sometimes responsible for some of the most common chronic clinical disorders of the upper gastrointestinal tract in humans, such as chronic-active gastritis, duodenal and gastric ulcer disease, low-grade B-cell mucosa associated lymphoid tissue lymphoma of the stomach, and gastric adenocarcinoma, which is the third leading cause of cancer death worldwide. The routes of infection have not yet been firmly established, and different routes of transmission have been suggested, although the most commonly accepted hypothesis is that infection takes place through the faecal-oral route and that contaminated water and foods might play an important role in transmission of the microorganism to humans. Furthermore, several authors have considered H. pylori to be a foodborne pathogen because of some of its microbiological and epidemiological characteristics. H. pylori has been detected in drinking water, seawater, vegetables and foods of animal origin. H. pylori survives in complex foodstuffs such as milk, vegetables and ready-to-eat foods. This review article presents an overview of the present knowledge on the microbiological aspects in terms of phenotypic characteristics and growth requirements of H. pylori, focusing on the potential role that foodstuffs and water may play in the transmission of the pathogen to humans and the methods successfully used for the detection of this microorganism in foodstuffs and water
Proteolytic and milk clotting activities in extracts obtained from the crustaceans Munida
In the present study, individuals of the crustaceans Munida have been investigated as a possible source of enzymes to be
used in cheese making as an alternative to calf rennet. The crustaceans were blended and the extracts were filtered and tested
for their proteolytic activity and milk clotting capability. The optimal values of pH and temperature of the total proteolytic
activity determined on azocasein were in the ranges pH 6.5–7.5 and 55–60 ◦C, respectively. The extracts showed a higher
capability to cleave S1-casein than - and k-casein. As determined with specific inhibitors, using azocasein or zymography,
the extracts appeared to contain serine proteases as well as cysteine and aspartic proteases. Hydrolysis of -casein gave
peptides which were different from those obtained with trypsin or a commercial calf rennet. Moderate milk clotting activity
was also present.
The ability to cleave casein, in particular S1-casein, and the moderate clotting activity, indicate that the extracts of the
crustaceans Munida could be useful in the dairy industry both for milk clotting, as an alternative or in addition to calf rennet,
and for the acceleration of cheese ripening in order to reduce time and costs of storage and maturation of cheese
The microbiological quality of Rana esculenta (L.) samples directed to the national and foreign markets
Left main coronary artery aneurysm: A case report and review of the literature
Left main coronary artery aneurysm is an uncommon feature of coronary artery disease in adults. We describe the case of a large aneurysm in a 58-year-old patient undergoing cardiac catheterization for effort angina and inducible myocardial ischemia. Specific considerations about the underlying causes and therapeutic options are discussed
Going Beyond Counting First Authors in Author Co-citation Analysis
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
“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
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
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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