1,720,969 research outputs found
The Mammalian successions of Sicily and Sardinia: a tentative of correlation with the biochronological frame of the Italian peninsula
No full textIl Paleolitico nei Monti della Tolfa: Nuove ricerche e prospettive future
No full textNel presente contributo viene proposto un quadro di sintesi sulla Preistoria dei Monti della Tolfa, teso ad ampliare le conoscenze sulla Preistoria locale attraverso nuovi dati acquisiti sia tramite lo studio di materiali provenienti da recenti raccolte di superficie, sia a seguito di un intervento di scavo effettuato nel sito fossilifero di Ficoncella. Lo studio integrale delle nuove raccolte di materiale litico consente di porre le basi per una sequenza relativa delle diverse frequentazioni antropiche riconoscibili sul territorio dal Paleolitico al primo Olocene, con la consapevolezza che le informazioni presentate hanno una valenza conoscitiva tutt’altro che definitiva.A synthesis of the Prehistory of the Monti della Tolfa area is here presented merging the knowledge on local prehistory coming from previous research with a number of new data obtained by analysing material from recent surface surveys and by a preliminary excavation carried at the fossiliferous site of Ficoncella. The study of new collections enable us to outline the cultural sequence at the Monti della Tolfa area from the different Palaeolithic stages to, albeit with doubt, first Holocene
The evolution of Palaeoloxodon skull structure:Disentangling phylogenetic, sexually dimorphic, ontogenetic, and allometric morphological signals
No full textThis paper presents a reappraisal of evolution in the extinct Pleistocene straight-tusked elephant Palaeoloxodon, based on cranial morphology. Particular emphasis is given to the parieto-occipital crest (POC), a specialised structure of the Palaeoloxodon skull. A key aim of this contribution is to discuss the systematic significance of the so-called “Stuttgart” and “namadicus” cranial morphs among Eurasian Palaeoloxodon. Materials examined and discussed mostly represent large-sized continental species from several Afro-Eurasian localities, but includes also the small-sized endemic elephant Palaeoloxodon cf. mnaidriensis from the late Middle-early Late Pleistocene of Sicily. In Africa, where the lineage originated, the morphological evolution of Palaeoloxodon concerned both skull and molariform teeth, which became strongly hypsodont and bore up to 19 lamellae. This dental morphology underwent little notable evolutionary change in Eurasian Palaeoloxodon, contrasting to the marked disparity in their cranial morphology, best elucidated by variations in the POC. Maturation of a strong POC in Palaeoloxodon antiquus, P. namadicus and P. cf. mnaidriensis (Puntali Cave, Sicily) during ontogeny shows a consistent pattern: incipient folding at the M1 stage; complete folding at the M2 stage; further downward migration of the POC towards the nasals at the M3 stage. The POC morphology and variation result from complex interactions of factors, which include, to varying degrees, ontogeny (juvenile vs adult), allometry (e.g. skull size and shape) and possible phylogenetic inertia. Some evidence of sexual dimorphism in POC development is observed in P. namadicus, P. naumanni, and possibly P. antiquus, this is a possible allometric effect which reflects on the markedly greater body size of males at full maturity compared to females. Skull shape and variability of the POC, as well as postcranial proportions, support the specific separation of P. namadicus and P. antiquus. However, the observed pattern of intrapopulational POC variability from German and Italian P. antiquus samples does not support a turnover of the two distinct Palaeoloxodon species in Europe during the Middle Pleistocene (MIS 11–MIS 7). The poorly known P. turkmenicus might represent a separate Middle Pleistocene Palaeoloxodon species from Central Asia more plesiomorphic than either P. antiquus or P. namadicus. P. naumanni from Japan possesses a combination of primitive and derived, autapomorphic characters, supporting its interpretation as an early offshoot during Eurasian Palaeoloxodon evolution.</p
A reappraisal of the Early to Middle Pleistocene Italian Bovidae
No full textDuring the Quaternary, bovids are common elements in the Italian local faunal assemblages (LFAs).
Representatives of Bovini tribe are continuously present, albeit with different lineages. Caprini are
sporadically recorded by several genera, and Antilopini are less represented, only during the Early
Pleistocene in the middle and early late Villafranchian local faunal assemblages (LFAs).
Diversity and ecological role of continental representatives of Italian Bovidae varied with LFAs as well
as in faunal units (FUs) throughout the Early and Middle Pleistocene. Species richness and diversity
peaked during the early late Villafranchian land mammal age (LMA) and then decreased in the post-
Jaramillo Early Pleistocene and at the beginning of the Middle Pleistocene (early and early middle
Galerian LMA). That time was characterized by the exclusive presence of bovids preferring open environments.
The small-sized bovids disappeared by the late Villafranchian, but a major renewal of the guild
took place at the transition from the Galerian to Aurelian LMA) (late Middle Pleistocene).
Endemic species are recorded in a few Italian islands: goat-like bovids with uncertain phylogenetic
affinity are recorded from the Late Pliocene to the Early Pleistocene in Sardinia, while subspecies of
Bovini, reduced in size, were present in Sicily during the Late Middle and Late Pleistocene and have been
claimed as present on the island of Pianosa (Tuscany
Mammuthus meridionalis (Nesti, 1825) from Campo di Pile (L'Aquila, Abruzzo, Central Italy)
No full textIn the summer of 2009, four molars and two tusks, of a single individual of Mammuthus meridionalis, were discovered at Campo di Pile (L’Aquila, Abruzzo, Central Italy) in a fluvial beach sediments of a depositional sequence dated to the late Early Pleistocene. A new fragmentary tusk of a second individual has been recently discovered not far from the former. In the L’Aquila Basin, southern mammoth remains have been already reported, in the nearby Campo di Pile, at Madonna della Strada-Scoppito, where a complete skeleton of M. meridionalis was found in sediments dating to the pre-Jaramillo Early Pleistocene, while some other isolated remains have been recorded at Rocca Santo Stefano and Colle Mancino. During the early Middle Pleistocene Mammuthus (? M. trogontherii) and Palaeoloxodon co-occurred in the faunal assemblage of Pagliare di Sassa. The Campo di Pile findings can confidently be regarded as intermediate in age between the Madonna della Strada and Pagliare di Sassa ones. Ongoing research on the Campo di Pile site contributes to enhancing our knowledge of the Quaternary fauna and paleoenvironmental evolution of L’Aquila Basin
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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