1,721,012 research outputs found
Variazioni di cianobatteri e microalghe nei sedimenti e della comunità batterica planctonica nel lago alpino d'alta quota Colbricon superiore.
No full textMicrobiodiversità dei Laghi del Colbricon, Trentino, Italy, un approccio di tassonomia molecolare
No full textWe carried out a study of the prokaryotic and eukaryotic communities of the upper Colbricon Lake. The lake
is situated at 1922 m a.s.l., in the Natural Park Paneveggio-Pale di S. Martino, in an highly natural area despite the
presence of a frequently visited mountain lodge in the summer season. The analysis spanned over seven years and
involved a twofold approach: 1) limnological, concerning eukariotic phytoplankton and Cyanophyta; 2) biomolecular,
for the study of bacterial communities, achieving their systematic attribution by bioinformatics. We found 125 taxa
of eukaryotic phytoplankton and 17 Cyanophyta. The bacterial sampling in fall 2004 revealed 78 prokaryotic taxa.
The structure of the bacterial community has been compared with that previously observed, with the same methods
prior to the works of waste water drainage pipes re-channelling downstream of the lake. The comparison has allowed
to verify the substitution of the previously dominant species with species of different ecological attitude. The former
were represented by weakly-pathogenic microorganisms indicative of an anthropic impact, while the new ones are not
of clinic kind but reveal an increase of trophic conditions and the presence of hydrocarbon residues, whose origin may
be related to the installation near the lodge of a diesel-fuelled auxiliary generator
Comparison between culturable and non culturable bacterial communities in an alpine lake ecosystem
No full textTaxonomical analysis of the suspended bacterial faction in the dromedary rumen fluid
No full textAn analysis of the dominant microbial taxa present in suspension within the rumen fluid from slaughtered one-humped camel (Camelus dromedarius) in Algeria was carried out using culture-independent molecular techniques. The rumen fluid of freshly eviscerated animals was sampled by a syringe and filtered through 0.22 μm filters in sterile conditions. Lyophilized filters were subsequently used as starting material for bacterial lysis and total DNA extraction procedures using DNA purification kits and suitably adapted protocols. The gene corresponding to the small subunit of ribosomal RNA (16S rDNA) was PCR-amplified from the bulk of DNA using eubacterial primers, and the pool of amplicons was ligated to plasmids and cloned in Escherichia coli, generating a clone bank of several hundred individuals representative of the rumen bacterial community. A preliminary analysis of 86 clones, sorted by amplified ribosomal DNA restriction analysis (ARDRA), and sequenced by Applied Biosystems automated sequencing using fluorescent terminators yielded the following results. The most abundant amplicon belonged to the Pseudomonas genus encompassing over 65% of the clones. Pseudomonas lutea appeared the most frequent homology hit in a BLAST GenBank comparison. The remaining flora featured taxa include (in order of deceasing abundance): Synechococcus sp., Moraxella osloensis, Sphingomonas sp., Diaphorobacter nitroreducens, Acinetobacter sp., Ruminococcus albus, Propionibacterium acnes and Comamonas sp. The data constitute the baseline for a comparison of the results with those that will be obtained by further metagenomic approaches to compare the fluid associated bacterial community with those attached to the solid particulate fraction
Analisi di fingerprint molecolare delle comunità batteriche negli humus di peccete alpine
No full textSei foreste Trentine di abete rosso sono state studiate prendendo in considerazione il DNA dei geni per l’RNA ribosomale 16S della comunità batterica amplificati mediante PCR. I siti includevano tre tipi di roccia madre, esposizione nord e sud e quattro fasi evolutive del bosco per un totale di 24 combinazioni. Il DNA amplificato e digerito con enzimi di restrizione è stato ordinato in cluster attraverso un software di analisi dell’immagine. L’analisi dei cluster ha evidenziato il seguente ordine di importanza dei fattori nel plasmare le differenze tra le comunità microbiche: roccia madre, esposizione e fase evolutiva del bosco
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
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