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Microbiological and calorimetric investigations on degraded marbles from the Cà d'Oro facade (Venice)
No full textMicrobiological, physicochemical and biochemical investigations were carried out on degraded marble samples from the Ca d'Oro facade (Venice) in order to verify the presence of biodeterioration agents. The aerobic heterotrophic bacteria (mean value 10(5) CFU/g marble), which were also observed by scanning electron microscope (SEM), were characterized as belonging to the Micrococcus and Bacillus genera. Nitrifying and sulphooxidizing bacteria were not found in any samples. The fungi (mean value 10(2) CFU/g marble) were attributed to the Penicillium and Aspergillus genera. Enrichment cultures revealed the presence of photosynthetic microorganisms belonging to the div. Cyanophyta and Chlorophyta.
The metabolic activity of the microorganisms derived from the cultural tests, was confirmed by the ATP content extracted directly from the powdered marble samples (average 3170 pg ATP per g marble).
Microbiological alterations of stone are the result of the metabolic activity of the microorganisms, whose heat production is an expression of this activity. Confirmation of the presence of the microorganisms on the degraded marble samples was, therefore, obtained by calorimetric investigations, which revealed that the process is completely exothermic and can be divided into two phases: the first showed the attainment of a plateau, typical of a zero-order reaction; the second was characterized by a peak followed by an abrupt arrest
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Research on chromatic alterations of marbles from the fountain of Villa-Litta (Lainate, Italy)
No full textThe fountain of Galatea at Villa Litta (Lainate, Milan) showed abundant flowerings of black spots accompanied by little red spots on the marble surface. On these altered areas no chemolithotrophic bacteria were found, although many heterotrophic microorganisms were present. The high number of colonies of Alternaria alternata isolated by black spots may induce us to believe that this fungal strain is the cause of such alteration. From the red areas however, in spite of the high number of heterotrophic bacteria (10(6) CFU/g marble), only a few red pigmented microbial strains classified as Micrococcus roseus, Flavobacterium sp. and Rhodotorula minuta were isolated. The resonance Raman spectra carried out on the red spots showed the absence of carotenoids, whilst the normal Raman spectra showed the presence of minium (Pb3O4). The lead probably derives from the pipes of the fountain.
Two biocides, Neo-Desogen and Cequartyl, were tested by minimum inhibitory concentration on the isolated microorganisms: R. minuta showed a higher sensitivity to both biocides compared with A. alternata, whilst M. roseus and Flavobacterium sp. showed more sensitivity towards Cequartyl. Three years after treatment with Neo-Desogen, small black and red spots were found. Microbiological analyses and ATP determination showed a new colonization of the heterotrophic bacteria (10(6) CFU/g) corresponding to the red spots, and of Mycetes (10(3) CFU/g) corresponding to the black ones
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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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