1,720,964 research outputs found
Bacteria associated to spontaneous plants in a historical PCB polluted soil show potential to sustain natural attenuation
No full textThe SIN Caffaro is a large polluted site of national priority located in Italy, originated by the activities of a former chemical factory. The site is highly contaminated by chlorinated persistent organic pollutants, mainly constituted by polychlorobyphenils (PCBs), together with heavy metals and metalloids, in variable concentrations and uneven distribution. We aimed to explore the diversity of root-associated bacterial communities driven by different plant species spontaneously established in abandoned agricultural soils within the most polluted area in the site. The overall structure of the non-vegetated and root-associated soil fractions bacterial communities was described by high-throughput sequencing of the 16S rRNA gene, and a collection of rhizobacteria was established and tested for plant growth promotion (PGP) traits and bioremediation potential. The results showed that the recruitment of specific bacterial communities in the root-associated soil fractions was driven by both soil fractions and plant species. PCR-based detection in the soil metagenome of bacterial bphA gene, encoding for the biphenyl dioxygenase α subunit, indicated that the soil in the site possesses metabolic traits linked to PCB degradation. The cultivable microbiota in the rhizosphere of the different plant species showed highly similar phylogenetic and functional composition, in terms of PGP and bioremediation potential. 72% of the strains harbored the bphA gene and displayed catechol 2,3-dioxygenase and 46% showed ACC deaminase activities, the latter considered a PGP trait contributing to plant tolerance to environmental stress. Overall, this work highlighted that spontaneous plant species differentially affect the rhizosphere bacterial community composition and harbor the intrinsic potential to sustain natural attenuation processes, further exploitable for rhizoremediation intervention at the SIN Caffaro
Rhizophere microbiota harborng PCB degrading potential is associated to spontaneous plants in a polluted site
No full textThe SIN Caffaro is a large polluted site of national priority located in Italy, originated by the activities of a former chemical factory. The soil in the site presents a mixed contamination of halogenated persistent organic pollutants (PCBs, dioxins and furans), heavy metals and metalloids in variable concentrations, uneven distributed in the area and often exceeding the safety values. After the closure of the production plant, only the process of natural attenuation occurred in the SIN Caffaro soils. We aimed to explore the natural attenuation potential of the SIN Caffaro soil microbiota, focusing on the interactions between plants and associated bacteria. We studied the phylogenetic and functional diversity of the microbiome associated to three plant species naturally selected in the most contaminated area of the SIN Caffaro. The soil bacterial community was described by Illumina sequencing of the 16S rRNA gene, and a collection of rhizobacteria was established and tested for plant growth promotion (PGP) traits and bioremediation potential. The results showed that both the soil niche and the plant species shaped the composition of the resident microbiota, which was more strongly influenced by the plant species in the rhizosphere than in the soil surrounding roots. Hence, we can speculate that the “rhizosphere effect” was stronger than the high pollutant concentration in shaping the bacterial community structure. The microbiota selected in all the soil niches showed nevertheless a degrading potential, according to the PCR-based detection of the bphA gene, encoding for the biphenyl dioxygenase α subunit, in the soil metagenome. The cultivable microbiota in the rhizosphere of the different plant species showed highly similar phylogenetic and functional composition, in terms of PGP and bioremediation potential. A large part of the strains harbored the bphA gene and displayed catechol 2,3-dioxygenase and ACC deaminase activities, the latter considered a PGP trait contributing to plant tolerance to environmental stress. Overall, this work highlighted that spontaneous plant species differentially affect the rhizosphere bacterial community composition and harbor the intrinsic potential to sustain natural attenuation processes, further exploitable for rhizoremediation intervention at the SIN Caffaro
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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