1,720,958 research outputs found
Alloscardovia theropitheci sp. nov., isolated from the faeces of gelada baboon, the 'bleeding heart' monkey (Theropithecus gelada)
No full textA novel irregularly shaped and slightly curved rod bacterial strain, GLDI4/2T, showing activity of fructose 6-phosphate phosphoketolase was isolated from a faecal sample of an adult gelada baboon (Theropithecus gelada). Phylogenetic analyses based on 16S rRNA genes as well as multilocus sequences (representing fusA, gyrB and xfp genes) and the core genome revealed that GLDI4/2T exhibited phylogenetic relatedness to Alloscardovia omnicolens DSM 21503T and to Alloscardovia macacae DSM 24762T. Comparative analysis of 16S rRNA gene sequences confirmed the phylogenetic results showing the highest gene sequence identity with strain A. omnicolens DSM 21503T (96.0 %). Activities of α- and β-gluco(galacto)sidases were detected in strain GLDI4/2T, which is characteristic for almost all members of the family Bifidobacteriaceae. Compared to other Alloscardovia species its DNA G+C content (43.8 mol%) was very low. Phylogenetic studies and the evaluation of phenotypic characteristics, including the results of biochemical, physiological and chemotaxonomic analyses, confirmed the novel species status for strain GLDI4/2T, for which the name Alloscardoviatheropitheci sp. nov. is proposed. The type strain is GLDI4/2T (=DSM 106019T=JCM 32430T)
Bifidobacterium jacchi sp. nov., isolated from the faeces of a baby common marmoset (Callithrix jacchus)
Full text linkA novel Bifidobacterium strain, MRM 9.3T, was isolated from a faecal sample of a baby common marmoset (Callithrixjacchus). Cells were Gram-stain-positive, non-motile, non-sporulating, non-haemolytic, facultatively anaerobic and fructose 6-phosphate phosphoketolase-positive. Phylogenetic analyses based on 16S rRNA genes as well as multilocus sequences (representing hsp60, rpoB, clpC, dnaJ and dnaG genes) and the core genomes revealed that strain MRM 9.3T exhibited phylogenetic relatedness to Bifidobacterium myosotis DSM 100196T. Comparative analysis of 16S rRNA gene sequences confirmed the phylogenetic results showing the highest gene sequence identity with strain B.ifidobacterium myosotis DSM 100196T (95.6 %). The average nucleotide identity, amino acid average identity and in silico DNA-DNA hybridization values between MRM 9.3T and DSM 100196T were 79.9, 72.1 and 28.5 %, respectively. Phenotypic and genotypic features clearly showed that the strain MRM 9.3T represents a novel species, for which the name Bifidobacterium jacchi sp. nov. is proposed. The type strain is MRM 9.3T (=DSM 103362T =JCM 31788T)
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
Metagenomic characterisation of gut microbiota in IBS patients
No full textIntroduction: Irritable Bowel Syndrome (IBS) is a gastrointestinal (GI) disorder that exhibits different GI and neurological symptoms such as abdominal pain, diarrhoea, constipation and mood disorders. The gut microbiota play an important role in modulating the communication between the Central Nervous System (CNS) and the GI tract, the so-called microbiota-gut-brain axis. In this context, IBS is a clear example of the alteration of the fine equilibrium between the gut microbiota and the CNS. Furthermore it has been observed that probiotic treatments of IBS results in the relief of GI and neurological symptoms, thus we could hypothesize the direct impact of the gut microbiota on IBS physiopathology. Since the IBS bacterial gut microbiota has been extensively studied we focused our attention also on the fungal counterpart of the gut microbiota, "the mycobiota".
Methods and aims. The aim of the present work was to evaluate biodiversity in bacterial and fungal microbiota of a cohort of 20 IBS subject and 21 healthy subject (HS) through culture-based and metagenomics approaches. The bacterial diversity that relies on DNA polymorphism has been performed by means of cluster analysis of ARDRA profiles. Moreover the absolute abundances of bifidobacteria and enterobacteria has been evaluated by qPCR. For IBS gut mycobiota characterization, fungal strains from IBS stool samples were isolated and identified by mean of ITS1-4 sequencing. Furthermore, isolates were phenotypically characterized to evaluate their resistance to GI tract stresses (temperature, low pH and oxbile resistance), while Candida isolates were further clustered by means of their RAPD profiles.
Results: The cluster analysis of ARDRA profiles showed that IBS bacterial microbiota clusters apart from HS microbiota. In addition we observed a 2.8-fold increase in the absolute abundance of enterobacteria in IBS subjects vs HS. The analysis of the gut mycobiota revealed significant differences in fungal isolates abundance in IBS subjects vs HS even if we did not find any significant difference in species richness. In particular, results showed an abundance of fungi (61.8% C. albicans), with a higher number of colony count 4.7 log10 CFU/g faeces in IBS subjects respect to HS faecal samples with 1.9 log10 CFU/g (48,75% C. albicans).
RAPD prolfile analysis of C. albicans and C. parapsilosis showed that IBS isolates clustered apart from HS isolates, suggesting their different genotypical background. Finally, we observed that IBS fungal isolates showed different phenotypical features with an increased ability to growth to high temperatures and low pH respect to isolates from HS.
Conclusions: Our results showed the presence of alterations in the microbial community structure of IBS subjects, both at bacterial and fungal level. The absolute abundance of enterobacteria in IBS subjects suggests their connection with putative inflammatory phenomena as previously observed in IBS and other pathologies (Lee and Park, 2014). The phenotypical characterization of IBS fungal isolates revealed that such isolates showed a different response in respect GI-like stresses. Moreover we observed that C. albicans and C. parapsilosis isolates from IBS are both phenotypically and genotypically different from HS Candida isolates suggesting their putative different ecological distribution. Finally we could hypotesize that dysbiosis of the gut microbiota in IBS could be one of the driving factor in IBS pathophysiology that could be responsible of intestinal fungal population overgrowth.
Lee JY, Park KS. 2014. World J Gastroenterol 20:2456-246
Gut microbiota profiles and characterization of cultivable fungal isolates in IBS patients
Full text linkStudies so far conducted on irritable bowel syndrome (IBS) have been focused mainly on the role of gut bacterial dysbiosis in modulating the intestinal permeability, inflammation, and motility, with consequences on the quality of life. Limited evidences showed a potential involvement of gut fungal communities. Here, the gut bacterial and fungal microbiota of a cohort of IBS patients have been characterized and compared with that of healthy subjects (HS). The IBS microbial community structure differed significantly compared to HS. In particular, we observed an enrichment of bacterial taxa involved in gut inflammation, such as Enterobacteriaceae, Streptococcus, Fusobacteria, Gemella, and Rothia, as well as depletion of health-promoting bacterial genera, such as Roseburia and Faecalibacterium. Gut microbial profiles in IBS patients differed also in accordance with constipation. Sequence analysis of the gut mycobiota showed enrichment of Saccharomycetes in IBS. Culturomics analysis of fungal isolates from feces showed enrichment of Candida spp. displaying from IBS a clonal expansion and a distinct genotypic profiles and different phenotypical features when compared to HS of Candida albicans isolates. Alongside the well-characterized gut bacterial dysbiosis in IBS, this study shed light on a yet poorly explored fungal component of the intestinal ecosystem, the gut mycobiota. Our results showed a differential fungal community in IBS compared to HS, suggesting potential for new insights on the involvement of the gut mycobiota in IBS. KEY POINTS: Comparison of gut microbiota and mycobiota between IBS and healthy subjects Investigation of cultivable fungi in IBS and healthy subjects Candida albicans isolates result more virulent in IBS subjects compared to healthy subjects
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
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