1,720,955 research outputs found
Fungi as bioresources for remediation of HCH-contaminated soils: from microbial community-level physiological profile to selective isolation in enrichment
No full textThe interaction between human activities and global change (including persistent chemicals
pollution) poses severe threats for the soil microbiota thus reducing the provision of ecosystem
services1. In this context -, -, and -hexachlorocyclohexane (HCH) are highly persistent organic
pollutants ofglobal concern, and a severe risk for human health and ecosystem functioning.
Soil fungi, thanksto the ability to tolerate, bioaccumulate and biodegrade HCH, are important
bioresources as biobased solutions for HCH-contaminated soil remediation. The study area
was selected within the National Priority Site “Bacino del Fiume Sacco” in the Metropolitan
City of Rome (Italy). Soil cores, up to 1 m of depth, were collected from 2 plots and later
divided in topsoil (TS: 0-10 cm) and subsoil (SS: 10-100 cm) samples. The first goal was to
characterize the microbial community level physiological profile, so the soil samples were
analysed by the Biolog EcoPlateTM Technique2 to compare metabolic activities of the
communities at different depths (TS and SS). Moving on, the project focused on the fungal
fraction of the microbial community, evaluating the fungal loaddifferences between TS and
SS, through the count of the colony forming units (CFUs/dry soil weight). The CFUs results
show a higher fungal load in topsoil than that in subsoil by one order of magnitude. To isolate
fungal bioresources suitable for HCH degradation, a selective enrichment procedure with a high
concentration HCH mixture as the only carbon source, was carried out. At the end of the
procedure several species, mainly belonging to Fusarium and Alternaria genera,were isolated
and are currently preserved in the Culture Collection of the Fungal Biodiversity Laboratory
(FBL) of the Department of Environmental Biology of Sapienza University of Rome. The
isolated fungi represent useful bioresources for further studies aimed at the development of
mycoremediation application for HCH contaminated soil remediation
Fungi in action against hexachlorocyclohexane: a focus on biosurfactants from fungal biodiversity
No full textHexachlorocyclohexane (HCH) is a highly persistent organic pollutant of global concern, involving severe
risks for human health and ecosystem functioning. Mycoremediation represents a feasible nature-based
solution for the restoration of soils polluted by HCH thanks to the ability of fungi to tolerate, bioaccumulate
and degrade it. Known for its insecticidal properties of one of its isomers (γ-HCH), it has been used for a long
time in European soils and despite the ban in the Stockholm Convention, high concentrations exceeding the
threshold values have been found in many areas. One of this is the National Priority Site “Bacino del Fiume
Sacco” within the Metropolitan City of Rome that has been selected as study area. Soil cores up to 1m of depth,
divided in topsoil and subsoil samples, were collected from 2 plots. To isolate fungi able to utilize HCH as the
sole C-source, an isolation in enrichment conditions was carried out providing an high concentration of
isomers’ mixture (α-, β-, γ- and δ-HCH). A total of 49 fungal strains was isolated, mostly belonging to
Fusarium and Alternaria genera. To evaluate the ability of these fungi to produce biosurfactants, metabolites
that enhance HCH biodegradability, three tests were carried out: oil emulsification activity test, oil
displacement test and drop collapse assay. The results of the assays showed the ability of some strains to
produce biosurfactants, making them suitable candidates for further investigation
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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