1,720,979 research outputs found
Archaeometric investigation of a Late Roman marble statue from Kaucana (RG) with considerations on the diffusion of Thasos marble in Sicily
No full textIn this work, a Roman white marble fragment of a headless body and a limestone ballast have been studied. The artifacts were discovered during the underwater archaeological explorations carried out in the Late Roman Harbor of Kaucana in Palmento of Punta Secca (RG; Sicily). Petro-archeometrics analysis to identify their provenience were performed with the aim to constraint archaeological hypothesis. In particular, to characterize the white marble we used a multi-technique approach to the petrographic description including the distinctive parameters AGS, MGS and GBS carried out by optical microscopy (MO), whereas mineralogical and chemical analysis were obtained respectively by means of X-Ray Diffraction and X-Ray Fluorescence with a portable instrument. Furthermore, the determination of the ∂18O and ∂13C isotopic ratios gave important information for the identification of the provenience of marble by comparison with literature data. Regarding the ballast, the characterization of the limestone was carried out by traditional petrographic, mineralogical and chemical methods. Finally, information about morphology and causes of underwater deterioration suffered by the materials was obtained by SEM-EDS analysis. All the data strongly suggest the provenance from Capo Vathy quarry in Thasos island (Greece) for the marble. Whereas for the ballast, both a Thasian and south Sicilian origin is excluded. This paper contributes to reconstructing the marble routes from Greece to the western parts of the Roman Empire
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
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
Limiti di carica microbica ed accettabilità delle carni avicole fresche
Full text linkThe minimum number of bacteria, which correlate to end of shelf-life, should be defined by producers in order to establish microbiological standards at the end of
productive process or at specifie defect action points, taking into account the possible temperature conditions the various products will probably meet. This would allow the quality assurance of all lots of products until the end of declared shelf life. Entire chicken, sliced chicken breast,
skewers of chicken with pepper, ripened chicken leg and cordon bleu samples were stored at temperature condition from -0.2° to 5.9°C for 9-11 days. Then they were analysed for microbiological traits and, on the basis of sensorial characteristics, were classified as acceptable, marginally acceptable or not acceptable. It was defined the maximum number ofPseudomonasspp., total coliforms or total plate count at which unacceptable products were not found and significance of these discriminatory limits was evaluated.Per stabilire la durata commerciale delle diverse preparazioni di carni avicole i produttori dovrebbero conoscere quali sono le concentrazioni minime di batteri alteranti correlabili alla comparsa di alterazioni e quali sono, quindi, gli standard microbiologici in fase di produzione od in specifici punti critici di controllo (defect action point) che permettano di assicurare, in condizioni programmate di temperatura, la qualità di un lotto di produzione fine al termine indicato in etichetta. Campioni di diversi lotti di busti di pollo, petti di pollo a fette, spiedini con peperone, fusotti ripieni e cordon bleu sono stati sottoposti a regimi di temperatura tra -0,2° e 5,9°C per 9-11 giorni. Al termine di questo periodo sono stati fatti controlli microbiologici e sulla base
delle caratteristiche organolettiche sono stati classificati accettabili, marginali o inaccettabili. È stato quindi individuato il limite più alto diPseudomonasspp., coliformi totali o carica mesofila totale al di sotto del quale non fossero riscontrabili unità inaccettabili ed è stata valutata la significatività
di questo limite discriminante
Heat resistance of Listeria monocytogenes persistent cells following osmotic stress in cooked pork sausages
No full textPersistent bacteria are subset of cells capable of surviving bactericidal treatments longer. They originate in response to environmental stressors and show a longer lag phase compared to the rest of the population they are part of. Impact of persistent cells on food safety and role of common food preservation techniques in their formation are still unclear. This study aims to investigate whether osmotic stress induces formation of persistent cells in Listeria monocytogenes capable of resisting longer during cooking cycle of pork sausages. Lag-phase duration at single-cell level of a strain grown in 6%-NaCl broth using image processing software was first investigated. Then, trend of the strain inactivation curve was evaluated in experimentally contaminated pork sausages cooked at 65 degrees C for 11 min. Results showed that salt triggers the formation of persistent cells characterised by a longer lag phase and increased heat resistance, posing a concern especially for ready-to-eat foods
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