1,721,027 research outputs found
Application of Photometric Stereo in the optical field and Scanning Electron Microscopy. Physical sculptures from Archaeology to Microelectronics
No full text
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
Toxicological outcomes linked to e-cigarette consumption: evidence from an in vivo model
No full textBackground:
Designed to deliver nicotine avoiding tobacco combustion, electronic cigarettes (e-cigs) are aggressively promoted as safer alternative to tobacco products and a putative approach to smoking cessation. However, to date the risk-benefit ratio remains largely unknown and recent investigations have questioned their safety. Here we presented our recent in vivo studies on the toxicological aspects associated to the electronic delivery systems.
Methods:
Male Sprague Dawley rats were whole-body exposed to the vapour generated by the devices. The e-cig was equipped with different coils (1.5 and 0.25 Ohm) and the Voltage applied ranged from 3.5 to 5.5 V in order to explore the role of these parameters on toxicological outcomes.
The treatment was carried out loading the device with e-liquid containing or not 18 mg/mL (1 mL/day) of nicotine. E-cig treated animals were subjected to the procedure for 3 h/day for 28 days. The levels of O2, N2, and CO2 were monitored by GC/MS to establish safe O2/N2 and CO2/ O2 ratios in the cages.
Furthermore, the experiments were repeated considering also “non-liquid devices” with alternative heating systems able to heat tobacco.
Results:
When e-cig was run at high voltage (5.5 V; 18 mg/mL nicotine) we recorded the release of hazardous carbonyl compounds (such as formaldehyde, acetaldehyde and acrolein). The animals showed a powerful booster effect on phase-I carcinogen-bioactivating enzymes, an impairment of the antioxidant and phase II catalysts, related to the increment of oxygen free radical (ROS) production, and DNA oxidation through 8-hydroxy-2′-deoxyguanosine yield in lung tissue. Insights into the genotoxicity also emerged from the extensive DNA damage in leukocytes measured by the comet assay, the increment in the percentage of immature micronucleated reticulocytes and the increased number of revertants in the urine. Lowering the voltage at 3.5 V and loading the device with a nicotine-free liquid, we still found aldehydes in the mainstream, and noteworthy, their amount enhanced moving form nicotine to nicotine-free liquids. Interestingly, the aldehydes increased as the resistance decreased from 1.5 to 0.25 Ohm, and the frames from electron microscope confirmed a disorganization of alveolar and bronchial epithelium more marked in the 0.25 Ohm group.
Finally, since changes in liver parameters including ALT and hepatocellular vacuolization in rats exposed to the vapour from “non-liquid e-cigs” were reported, we added a breakthrough finding on treated animals showing a disruption of the redox homeostasis, with higher levels of ROS, and increased markers of oxidative injuries such as lipid peroxidation and protein carbonylation, combined with an impairment of the enzymatic and non-enzymatic antioxidant defence systems.
Conclusion:
As a whole, our studies show how electronic delivery devices can trigger detrimental phenomena typically induced by conventional cigarettes
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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