1,724,457 research outputs found
4468. Sepet (M.), Jeanne d'Arc, 1869
No full text4468. Sepet (M.), Jeanne d'Arc, 1869. In: Molinier Auguste. Les Sources de l'histoire de France - Des origines aux guerres d'Italie (1494). IV. Les Valois, 1328-1461. Paris : A. Picard et fils, 1904. p. 312
Non-radioactive in situ hybridization for the detection of cytomegalovirus infections
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4468.pdf (Publisher’s version ) (Open Access
Linked collectors and determiners for: HSTM herbarium - Universidade Federal do Oeste do Pará - Herbário Virtual REFLORA.
No full textNatural history specimen data linked to collectors and determiners held within, "HSTM herbarium - Universidade Federal do Oeste do Pará - Herbário Virtual REFLORA". Claims or attributions were made on Bionomia by volunteer Scribes, <a href="http://bionomia.net/dataset/97802be9-3e72-4468-8611-0c9cd3a905a7">https://bionomia.net/dataset/97802be9-3e72-4468-8611-0c9cd3a905a7</a> using specimen data from the dataset aggregated by the Global Biodiversity Information Facility, <a href="https://gbif.org/dataset/97802be9-3e72-4468-8611-0c9cd3a905a7">https://gbif.org/dataset/97802be9-3e72-4468-8611-0c9cd3a905a7</a>. Formatted as a Frictionless Data package
Micro-petrological Analysis of Shergottite Meteorite North West Africa 4468
No full textThis study investigates the chemical variations within mineral phases in the Martian meteorite sample North West Africa (NWA) 4468. Meteorites are the only samples of Martian rocks that can be studied directly. Their geochemical and mineralogical compositions provide key evidence for magmatic processes occurring on Mars. Recent observations of volcanic areas on Mars, e.g. the Athabasca Valles, suggest that Mars is in fact still a volcanically active planet. Application of micro-petrology, i.e. processes represented and recorded on a mineral-scale, is the only effective way to study meteorites which are exceedingly rare and found only as very small volume samples. Meteorite NWA 4468 is an example of a Shergottite, a group of 150-220 Ma Martian meteorites, typically basaltic in composition, coarse grained and enriched in incompatible elements. NWA 4468 is a basaltic sample with large pyroxene oikocrysts, olivines, oxides and plagioclase grains. The later have been shock-altered to maskelynite. Shergottites are generally thought to represent cumulates fractionated from high-volume melting of the lower, primitive, Martian mantle. Samples were examined using reflected light microscopy and backscattering electron-imaging, followed by detailed X-ray mapping of both the large olivine and pyroxenes crystals. The olivine crystals are generally not zoned in Fe and Mg, but do preserve phosphorus (P-) zoning. This occurs in about 20% of the olivine crystals and suggests early skeletal growth and subsequent ripening of the crystals, which in turn overprinted any Fe and Mg zoning that may have originally occurred. This type of P-zoning has been noted in terrestrial basaltic samples and can used to make predictions about the growth history and cooling rates recorded. In this case the olivine crystals formed early in the crystallization history but also at elevated temperatures. Pyroxene oikocrysts show distinct zoning from pigeonite to augite, i.e. from Ca-rich and Ca-poor sectors within individual grains. Zoning in Fe and Mg is also partially preserved in the pyroxene crystals. This can be used to determine the minimum recorded crystallization temperatures and relative cooling rates. The pyroxene crystals in this example likely formed later and at cooler temperatures than the olivine crystals. Analyses of oxides and have also been carried out to enable as wide a range of mineral thermobarometers as possible to be applied. Applied thermometry and barometry, combined with characterization of preserved micro-textural features in NWA4468, will provide further insight into the overall formation of large magmatic systems on Mars.
Keywords:Shergottite Northwest Africa 4468, Geochemistry, Crystallization. Magmatism, Mars, Phosphorous zoning
Pages: 52
Supervisor: Richard Co
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
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
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