1,720,962 research outputs found
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
Bacterial diversity of a wooded riparian strip soil specifically designed for enhancing the denitrification process
No full textThis research is part of a project aimed at verifying the potential of a specifically assessed wooded riparian zone in removing the excess of combined nitrogen from the Zero River so as to reduce nutrient inputs into the Venice Lagoon. Among the specific objectives of the project, there was the determination of change in the composition of the microbial populations of soil of the wooded riparian strip. The composition of the bacterial communities collected at different depths inside and outside the riparian strip was determined by combined approaches involving cultivation (CFU), microscopic approaches (CTC test), and DNA-based techniques (ARDRA and DGGE). The size of the living population was the same inside and outside the experimental strip, with a minor percentage of culturable bacteria. Higher numbers of metabolically active bacteria and higher bacterial diversity were detected in the internal soil, with deeper soil layers showing reduced diversity, thus indicating that soil management within the riparian strip effectively supports the viability of bacterial communities. Total operational taxonomic units (OTUs) and percentage of single OTUs were also found to be always higher in the internal soil samples for all soil layers, with the percentage of Firmicutes increasing and Actinobacteria decreasing with depth. The increasing soil organic carbon inputs due to the contribution of the growing plants were found to support bacterial diversity in all soil layers. DNA-based analysis also indicated a clear effect of the applied treatments on soil bacterial diversity and a well-defined separation of the bacterial communities related to the different soil layers of the riparian stri
Vegetation, soil and hydrology management influence denitrification activity and the composition of nirK-type denitrifier communities in a newly afforested riparian buffer
No full textSoil microbial community composition and activity could be affected by suitable manipulation of the environment they live in. If correctly applied such an approach could become a very effective way to remediate excess of chemicals. The concentration of nitrogen, especially nitrate deriving from
agricultural managements, is generally found to increase in water flow. Therefore, by forcing the water flow through a buffer strip specifically designed and possibly afforested with suitable plant species, may result effective in reducing high nitrogen contents. The management of a riparian buffer may definitely affect the soil microbial activities, including denitrification, as well as the composition of the
community.
The present study reports on the changes occurred in terms of denitrifying microbial community composition, as compared to that of a neighbouring agricultural area, as a consequence of hydraulic management coupled to the suspension of farming practices and to the development of the woody and
herbaceous vegetation.
With this aim, denitrification was repeatedly measured and the data obtained were related to those deriving from a specific analysis of bacterial groups involved in denitrification. nirK, encoding for nitrite reductase, an enzyme essential for the conversion of nitrite to nitric oxide and considered the
key step in the denitrification process, was chosen as the target gene.
The main results obtained indicated that denitrification activity changes in riparian buffer as compared to agricultural soil and it is strongly influenced by carbon availability and soil depth.
Although no significant differences on the community composition between superficial (0–15 cm) and medium (40–55 cm) layers were observed, the nirK-type denitrifier community was shown to significantly differ between riparian and agricultural soils in both surface and medium layers
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
Characterization of the microbial diversity in the water fluxes of a wooded riparian strip set up for nitrogen removal
No full textThis research is part of a project aimed at verifying the potential of a specifically assessed wooded riparian zone in removing excess of combined nitrogen from the Zero river flow for the reduction of nutrient input into Venice Lagoon. Seasonal fluctuations of microbial populations in the water entering and leaving the wooded riparian strip were determined for at least two years. Combined approaches
involving cultivation, microscopic approaches and DNA bases techniques were adopted to characterize both culturable and total microbial community. Seven major bacterial lineages, namely Firmicutes, Gammaproteobacteria,Actinobacteria, Alphaproteobacteria, Betaproteobacteria, Flavobacteria, and
Sphingobacteria were present in water samples as revealed by 16S rDNA sequence analysis of the culturable fraction of the bacterial population.
Gammaproteobacteria were the most dominant both in spring and fall, although
distinct bacterial communities were clearly detectable for the two seasons.
However, while DGGE cluster analysis did not reveal significant differences
between irrigation and drainage ditches, a significant alteration was detected by
PCA based on 16S rDNA of the culturable fraction. Since the wooded riparian
strip was vigorously working in terms of N removing by plant uptake and
especially by microbial denitrification, as demonstrated by parallel studies
performed on the same experimental site (Gumiero et al., 2011), it is reasonable to
suppose that the culturable bacteria fraction is the one effectively carrying out the
required task. In other words, the wooded riparian buffer zone specifically assessed
for water remediation (nitrogen removal) is efficiently working as a result of the
special conditions there produced to support the work of specific microbial
populations. This is confirmed by the increase of metabolically active bacteria
detected at the drainage ditches.
Taken together, the overall results provide key indications for the management of a
phytoremediation sit
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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