1,720,957 research outputs found
Dating the context (or contextualizing the dating?): new evidences from the Southern Cemetery at Erimi-Laonin tou Porakou (EC-LC I)
No full textCollagen quality indicators for Radiocarbon dating of bones: new data on Bronze Age Cyprus
No full textRadiocarbon dating of bones can be very useful in archaeological contexts, especially when dealing with funerary deposits lacking material culture, e. g. pottery vessels. C-14 measurements of bone samples are usually performed on the extracted collagen residue. The content and the quality of collagen can vary significantly, mainly depending on bone preservation and diagenesis. Generally speaking, environmental conditions such as low pH level of soils, high temperatures, and percolating groundwaters, typical of arid and tropical zones, can affect the preservation of collagen; at the same time, bones recovered in such environments are more likely to be contaminated with carbon from the surrounding environment. Possible contamination of samples can also occur in temperate zones. While low collagen content is a condition we cannot overcome, we can use several chemical and elemental indicators in order to assess collagen quality. Among these, the C/N atomic ratio is considered a good parameter for detecting low-quality collagen and possibly contaminated samples. In a combustion and graphitization setup like that installed at INFN-LABEC, Florence, measurement can be easily performed using an elemental analyzer when combusting the sample prior to graphitization, thus requiring no extra effort (or extra amount of sample) during the preparation procedure. Bone samples recently C-14 dated at INFN-LABEC have confirmed that the measurement of C/N atomic ratios can give some indications of the collagen quality. The bone material was collected from 3 necropoles of the Bronze Age period in Cyprus (Erimi-Laonin tou Porakou, Lophou-Kolaouzou, and Erimi-Kafkalla&Pitharka, along the Kouris Valley), an area characterized by environmental conditions that do not favor bone preservation. Samples were treated to extract collagen and measured by accelerator mass spectrometry (AMS). C-14 results have been compared with the archaeological evidence, showing some relationship between measured C/N atomic ratios and collagen quality. In particular, when grouping the measured samples according to their C/N ratio, the agreement between C-14 dates and archaeological evidence is good or inconsistent when the C/N ratio clearly falls inside or outside the "recommended" range, respectively, with a still reasonable agreement also when it is slightly above the upper limit of that range
Strategies for sampling difficult archaeological contexts and improving the quality of radiocarbon data: the case of Erimi Laonin tou Porakou, Cyprus
No full textAfter decades of collaborative experience between archaeologists and radiocarbon scientists, with the aim at producing radiocarbon dates capable of answering the most various research questions, it is now widely recognized that an accurate sampling strategy is the cornerstone of a solid C-14-based chronology. In this paper, we discuss the sampling criteria required to obtain good quality C-14 data within a challenging archaeological context like the Bronze Age site of Erimi Laonin tou Porakou (Limassol, Cyprus). Following a dedicated sampling strategy, in the productive complex of the settlement, charcoal samples were collected from secure contexts according to stratigraphic examination of excavated strata and analysis of associated features and material culture. Micromorphology was also applied for a more accurate interpretation of individual deposits and reconstruction of depositional and post-depositional processes. In the necropolis, bone samples were selected among the fragmentary and commingled human remains through evaluation of the preservation state and the minimum number of individuals (MNI). A discrepancy between the charcoal and the bone C-14 determinations was encountered, probably due to old wood issues. The C-14 dates were analyzed using a Bayesian model that incorporates the archaeological information, and a preliminary C-14-based chronology was defined for this site
Little Big Data. On-going archaeological science-based researches at Bronze Age Erimi Laonin tou Porakou
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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
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