1,720,967 research outputs found
Resizing Lisowicia bojani. Volumetric body mass estimate and 3D reconstruction of the giant Late Triassic dicynodont
No full textBody size is one of the most crucial biological properties, with a major influence on ecology, metabolism and several physiological aspects. Recently the exceptionally large dicynodont Lisowicia bojani from the Late Triassic of Poland has been described. Using a regression formula based on long bone circumferences, an impressive body mass of 9.33 tons was reconstructed in the original description for this new and largest member of dicynodonts. The taxon is characterized by particularly robust long bones with very massive and stout shafts, thus raising the theoretical possibility that the regression formulae may have led to a substantial overestimate of the body mass. Here we present a new body mass estimate for Lisowicia based on 3D digital volumetric models, aiming to provide a more reliable and conservative estimate. The new body mass ranges from 4.87 tons to 7.02 tons for the adult taxon, with an average body mass of 5.88 tons; thus, the original value of 9.33 tons overestimates the weight of about 60%. Our study confirms empirically that volumetric methods for body mass estimates should be preferred and implemented whenever possible. Synapsids still had to wait until the Eocene to reach the enormous body mass of 9 tons
Reviewing the iconography and the central role of ‘paleoart’. Four centuries of geo-palaeontological art
No full textBetween the fifteenth and sixteenth centuries, the first naturalistic illustrations appeared in texts and treatises, marking the true and proper passage from simple literary works to real scientific contributions. Since that time, the geo-palaeontological literature and the world of scientific illustrations developed together. For a long time initially the scientist and artist coincided in the same person, until the emergence of the ‘paleoartist’, as a professional devoted to naturalistic representations. Here, we review the fundamental steps of ‘co-evolution’ between advances in scientific knowledge and their representation in ‘paleoart’. The study led to the identification of six principal ‘Genres’; in addition, a subdivision of the history and evolution of ‘paleoart’ into six periods or major ‘eras’ is proposed. The analysis is based on a dataset with a total of 605 authors, considering a time range between the first half of the 18th century up to 2020, with paleoartists from 42 different countries. The relationship between scientist and ‘paleoartist’ has been, and will be in the future, a constructive interaction of ‘reciprocal illumination’, where the questions asked by the artist represent a genuine propellant for the advancement of knowledge and the research itself
Spatial Patterns and Sampling Plan for Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae) and Related Parasitoids on Lettuce
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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
In vivo restoration and volumetric body mass estimate of Mammuthus Meridionalis from Madonna della Strada (Scoppitto, L’Aquila)
Full text linkIn this contribution we present an in vivo reconstruction and volumetric body mass estimate for the mounted skeleton of Mammuthus meridionalis on exhibit at the east bastion of the Spanish Fortress at L’Aquila (Abruzzo, Central Italy). The reconstruction has been obtained starting from a 3D photogrammetric model of the skeleton acquired via a micro-drones and by digitally adding a percentage of soft tissues according to the conditions observed in wild specimens. By applying to the volume the density range proposed in literature for extant proboscideans we obtain an estimate of the body mass in the adult male specimen ranging from 11.3 t to 11.5 t, with average body mass equal to 11.43 t. In addition, we compare the volumetric BM estimate with the BM predictive values obtained by means of traditional regression equations based on long bones linear dimension and shoulder height. The results confirm that the volumetric method is always preferable if sufficiently complete mounted skeletons are available, since application of regression formulas to single bony element can lead to an underestimation or overestimation up to 130%. As a general indication, weight estimates in extinct tetrapods based on single measures and single bones should be totally avoided, especially in groups morphologically and phylogenetically distant from extant reference taxa
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
Volumetric body mass estimate and in vivo reconstruction of the russian Pareiasaur Scutosaurus karpinskii
Full text linkPareiasaurs (Amniota, Parareptilia) were characterized by a global distribution during the Permian period, forming an important component of middle (Capitanian) and late Permian (Lopingian) terrestrial tetrapod biodiversity. This clade represents an early evolution of sizes over a ton, playing a fundamental role in the structure of middle and late Permian biodiversity and ecosystems. Despite their important ecological role and relative abundance around the world, our general knowledge of the biology of these extinct tetrapods is still quite limited. In this contribution we provide a possible in vivo reconstruction of the largest individual of the species Scutosaurus karpinskii and a volumetric body mass estimate for the taxon, considering that body size is one of the most important biological aspects of organisms. The body mass of Scutosaurus was calculated using a 3D photogrammetric model of the complete mounted skeleton PIN 2005/1537 from the Sokolki locality, Arkhangelsk Region, Russia, on exhibit at the Borissiak Paleontological Institute, Russian Academy of Sciences (Moscow). By applying three different densities for living tissues of 0.99, 1, and 1.15 kg/1,000 cm3 to reconstructed “slim,” “average” and “fat” 3D models we obtain average body masses, respectively, of 1,060, 1,160, and 1,330 kg, with a total range varying from a minimum of one ton to a maximum of 1.46 tons. Choosing the average model as the most plausible reconstruction and close to the natural condition, we consider a body mass estimate of 1,160 kg as the most robust value for Scutosaurus, a value compatible with that of a large terrestrial adult black rhino and domestic cow. This contribution demonstrates that barrel-shaped herbivores, subsisting on a high-fiber diet and with a body mass exceeding a ton, had already evolved in the upper Palaeozoic among parareptiles, shedding new light on the structure of the first modern terrestrial ecosystems
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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