1,720,967 research outputs found
Innovative experimental approach for identifying spatial relationships between PM oxidative potential and PM chemical composition and sources
No full textRecent studies identified the generation of oxidative
stress as one of the major mechanisms by which PM
exerts its adverse biological effects. The ability of PM to
induce oxidative stress is frequently estimated by
acellular oxidative potential (OP) assays, such as acid
ascorbic (AA), 2,7-dichlorofluorescenin (DCFH) and
dithiothreitol (DTT) assay, used as a proxy of ROS
generation in biological systems.
In this study we applied the AA, DCFH and DTT
assays to PM10 samples, previously chemically analysed
(Massimi et al, 2020), collected at 23 different sampling
sites in Terni (an urban and industrial hot-spot of
Central Italy), by using innovative and very-low volume
devices for PM sampling on membrane filters (HSRS -
High Spatial Resolution Sampler; Fai Instruments, Fonte
Nuova, Rome, Italy). The HSRS worked in parallel during
a two-month winter monitoring period. The sampling
sites have been chosen for spatially representing the
main local emission sources and the samplers were
located in order to cover the study area with around 1
km spatial resolution (Figure 1, upper panel).
In this study we aimed to assess the spatial
variability of the three acellular assays (Figure 1) in
order to investigate relationships between the different
OP results and the contribution of the local emission
sources to the total PM10. To our knowledge, the
comparison of the three OP assays applied to PM10
spatially-resolved samples has never been undertaken
so far. Furthermore, we applied the three OP assays to
size-segregated PM samples collected by a multistage
impactor (cut-sizes: 0.18, 0.32, 0.56, 1.0, 1.8, 3.2, 5.6, 10
and 18 μm) at three sampling sites (MA, CA and PR;
Figure 1, upper panel), characterized by different
strength of the main PM sources, in order to evaluate
the different sensitivity of the three acellular assays
toward fine and coarse particles.
The results showed that AA was particularly
sensitive toward coarse particles coming from the rail
network (close to GI, CR and HG), released by the
abrasion of train brakes. On the contrary, DCFH
appeared to be more related to PM10 coming from
industrial sources (steel plant at PR and OB) and
biomass burning (domestic biomass heating at BR),
while DTT was found to be sensitive only toward fine
particles released by biomass burning (burning of
carpentry waste products at FA and domestic biomass
heating at BR). The innovative experimental approach
allowed us identifying spatial relationships between PM
oxidative potential and PM chemical composition and
sources
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
Application of a chemical fractionation procedure for the characterization of leaf deposited PM
No full textVariations 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
Spatial mapping of element concentrations in PM10: A powerful tool to identify spatial relationships between emission sources and oxidative potential of PM
No full textDispelling 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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