1,720,965 research outputs found
Molecular fingerprinting of Helicobacter pylori strains from duodenal ulcer patients.
No full textAims: To characterize the molecular fingerprinting of Helicobacter pylori population isolated in duodenal ulcer
patients treated with triple therapy.
Methods and Results: Gastric biopsy specimens from corpus and antrum, were cultured for H. pylori isolation.
Helicobacter pylori eradication was evaluated after 4 and 16 weeks. DNAs of all isolates were characterized by
random amplified polymorphic DNA typing and cagA gene was also detected. After the therapy, five patients
harboured the microorganism at 4 weeks and two of them remained H. pylori positive at 16 weeks. The analysis of
DNA fingerprinting of strains isolated from antrum and corpus of patients susceptible to treatment, showed similar
patterns. Instead, when the therapy was not effective, strains isolated from sequential biopsies from initial and after
4 and 16 weeks, showed distinct fingerprintings and retained the cagA status, over time.
Conclusions: The drugs used for therapy could exercise an effect in genotypical rearrangement among H. pylori
cells.
Significance and Impact of the Study: The variableness among H. pylori strains represents a way to challenge
environmental stress
Detection of free and plankton-associated Helicobacter pylori in seawater.
No full textAims: To detect both free and plankton-associated Helicobacter pylori in seawater samples collected on the Italian
coast of the Adriatic Sea using a nested-PCR.
Methods and Results: Dissolved oxygen, pH, salinity and chlorophyll a were the parameters recorded together
with the characterization of zooplanktonic organisms. Plankton-associated H. pylori DNA was searched for in water
samples filtered through 200 and 64 lm nylon nets whereas free bacteria were retained with the subsequent
filtration through 0Æ22 lm pore-size membranes. Nested-PCR using primers for the glmM (ureC) gene was
performed to reveal the presence of H. pylori. The DNA sequencing of amplified products confirmed the specificity
of the assay. The sensitivity of the nested-PCR assay for H. pylori detection was 62 CFU per 100 ml in spiked water
samples. Helicobacter pylori either free or bound to planktonic organisms was found in seven of 12 monthly samples.
In particular, free bacteria were detected during the summer sampling and in November, December and March
associated to planktonic cells.
Conclusions: The presence of free and plankton-associated H. pylori in seawater suggests that it can be a
significant reservoir and a potential route of transmission for the microorganism.
Significance and Impact of the Study: Our study seems to provide a promising background to define new and
effective strategies for surveillance of this human pathogen
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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