1,720,996 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
Carbon sequestration potential and microbial diversity in vineyards under a climate change scenario – Preliminary results
No full textClimate change has a strong influence on soil organic carbon (SOC) stock and vulnerability, as well as on microbial biodiversity, across different agroecosystems including vineyards. A randomized block design, consisting of 3 blocks composed of 8 plots each, and two factors, i.e., land management practice (amendment, cover crop, bare soil) and climate manipulation (ambient temperature, warming), was set up in three study areas within the Veneto region (North of Italy). Open top chambers (OTC) were used to obtain a temperature increase of ~2 °C (SSP2-4.5). Soil samples will be collected at four times (after 0, 6, 12, and 18 months from the OTC placement) and at 3 depths (0-15, 15-30, and 30-45 cm) and characterized from the physical, chemically and microbiological point of view. From each sample, particulate and mineral-associated organic matter (POM and MAOM respectively) were isolated and characterized by elemental and thermal analysis. DNA was extracted from topsoils (0-15 cm) and metagenomic analyses were carried out.
The preliminary results show that, as expected, no significant differences in SOC stocks occur following 6 months of warming, while a general and slight increase in carbon concentration already occurs in plots with cover crops. In the latter, POM plays a greater role in SOC accrual but, regardless of the vineyard and the agronomic management, is the more labile one, as estimated by thermal analysis. Conversely, MAOM represents the main SOC pool, whose stability increases with depth. The microbiological analysis highlighted a significant difference in bacterial populations among the study areas. On the other hand, no significant differences were observed among treatments and climate manipulations. It is expected that results obtained after 12 and 18 months will help to better understand the effects of management practices in SOC and microbial dynamics in vineyards under a climate change scenario
Bacteria from black crusts on stone monuments can precipitate CaCO3 allowing the development of a new bio-consolidation protocol for ornamental stone
No full textThe microbial precipitation of CaCO3 is an emerging strategy for the consolidation of decayed limestone. Strains of Bacillus sp. and Micrococcus sp. isolated from black crusts were selected by polycyclic aromatic hydrocarbon enrichment culture and tested for their ability to precipitate CaCO3 by induced mineralization. Among the isolates, Bacillus sp. A2, B1, B5 and Micrococcus sp. A10 produced the largest quantities of biogenic calcite. Stone bio-consolidation was then tested using Carbogel as a carrier. The most efficient bio-cementation on limestone slabs was achieved by Bacillus sp. A2 and B1 and Micrococcus sp. A10. Bio-consolidation treatments were also applied to fragmented stones from the Church of Santa Maria dei Miracoli by inoculating the three bacterial strains individually or as a mixture. Bacillus sp. A2, Micrococcus sp. A10 and the mixture achieved the most efficient consolidation. Our data showed that Carbogel provides an appropriate substitute for natural biofilm formation in bio-consolidation protocols. Scanning electron microscopy and energy-dispersive X-ray spectroscopy revealed calcified bacterial cells filling the pores of stone specimens, increasing the calcium content by 100% more than a non-inoculated control treatment under the same conditions. Our new bio-consolidation protocol therefore provides an effective strategy to prevent the further deterioration of stone monuments
Mesocosm‐based simulations to optimize a bioremediation strategy for the effective restoration of wildfire‐impacted soils contaminated with high‐molecular‐weight hydrocarbons
Full text linkAims: We obtained four microbial isolates from soil exposed to forest fire and evaluated their potential bioremediation activity when combined with a biosurfactant-producing bacterial strain for the decontamination of wildfire-impacted soil polluted with high-molecular-weight (HMW) hydrocarbons. Methods and Results: We established mesocosm trials to compare three bioremediation strategies: natural attenuation, bioaugmentation and biostimulation. Chemical analysis, culture-dependent and culture-independent methods were used to evaluate the bioremediation efficiency and speciation of the microbial cenoses based on these approaches. After treatment for 90 days, bioaugmentation removed 75·2–75·9% of the HMW hydrocarbons, biostimulation removed 63·2–69·5% and natural attenuation removed ~22·5%. Hydrocarbon degradation was significantly enhanced in the mesocosm supplemented with the biosurfactant-producing bacterial strain after 20 and 50 days of treatment compared to the other bioremediation strategies. Conclusions: We found that the bioaugmentation approach was more effective than biostimulation and natural attenuation for the removal of HMW hydrocarbons from fire-impacted soil. Significance and Impact of the Study: Our study showed that micro-organisms from wildfire-impacted soil show significant potential for bioremediation, and that biosurfactant-producing bacterial strains can be combined with them as part of an effective bioremediation strategy
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
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