1,721,032 research outputs found
A look from the inside: MicroCT analysis of burned bones
No full textMicroCT imaging is increasingly used in paleoanthropological and zooarchaeological research to analyse the internal microstructure of bone, replacing comparatively invasive and destructive methods. Consequently the analytical potential of this relatively new 3D imaging technology can be enhanced by developing discipline specific protocols for archaeological analysis. Here we examine how the microstructure of mammal bone changes after burning and explore if X-ray computed microtomography (microCT) can be used to obtain reliable information from burned specimens. We subjected domestic pig, roe deer, and red fox bones to burning at different temperatures and for different periods using an oven and an open fire. We observed significant changes in the three-dimensional microstructure of trabecular bone, suggesting that biomechanical studies or other analyses (for instance, determination of age-at-death) can be compromised by burning. In addition, bone subjected to very high temperatures (600°C or more) became cracked, posing challenges for quantifying characteristics of bone microstructure. Specimens burned at 600°C or greater temperatures, exhibit a characteristic criss-cross cracking pattern concentrated in the cortical region of the epiphyses. This feature, which can be readily observed on the surface of whole bone, could help the identification of heavily burned specimens that are small fragments, where color and surface texture are altered by diagenesis or weathering.MicroCT imaging is increasingly used in paleoanthropological and zooarchaeological research to analyse the internal microstructure of bone, replacing comparatively invasive and destructive methods. Consequently the analytical potential of this relatively new 3D imaging technology can be enhanced by developing discipline specific protocols for archaeological analysis. Here we examine how the microstructure of mammal bone changes after burning and explore if X-ay computed microtomography (microCT) can be used to obtain reliable information from burned specimens. We subjected domestic pig, roe deer, and red fox bones to burning at different temperatures and for different periods using an oven and an open fire. We observed significant changes in the three-dimensional microstructure of trabecular bone, suggesting that biomechanical studies or other analyses (for instance, determination of age-at-death) can be compromised by burning. In addition, bone subjected to very high temperatures (600 degrees C or more) became cracked, posing challenges for quantifying characteristics of bone microstructure. Specimens burned at 600 degrees C or greater temperatures, exhibit a characteristic criss-cross cracking pattern concentrated in the cortical region of the epiphyses. This feature, which can be readily observed on the surface of whole bone, could help the identification of heavily burned specimens that are small fragments, where color and surface texture are altered by diagenesis or weathering
Synchroton Radiation Microprobe Analysis of Human Dental Calculi from an Archaeological Site: a New Possible Perspective in Palaeonutrition Studies
No full textUsing X-ray Microtomography to Discriminate Between Dogs’ and Wolves’ Lower Carnassial Tooth
Full text linkDogs and wolves exhibit similar dental features since they belong to the same species. Here we explore a new method to
discriminate between wild and domestic forms, based on the analysis of the internal structure of the teeth. We analysed the lower first molar of 21 dogs and 17 wolves. X-ray microtomographic analyses were performed and tooth tissue proportions were assessed by the proportion of the dentine volume. As a result, dog molars show a lower percentage of dentine than those of wolves. This analysis offers promising applications in the study of dog domestication origins
Shaft-hole axes from Caput Adriae made from amphibole-rich metabasites: evidence of connections between Northeastern Italy and Central Europe during the fifth millennium BC
No full textHere we show the results of a study concerning a small group of shaft-hole axes found in northeastern Italy, made from amphibole-rich metabasites, fine-grained and free of phenoblasts.
The main mineral phases are amphibole, ranging from actinolite to hornblende, and plagioclase (An10–15 and An70–77). The amphiboles generally show a needle shape and are often radially arranged. Quartz is present in thin veinlets, while ilmenite is widespread in small patches. The petrographic and geochemical features suggest that the axes originate from the southern thermal aureole of Tanvald granite in northern Bohemia. In accordance with this provenance, the typology of the tools shows similarities with the perforated shoe-last axes spread across Central Europe during the fifth millennium BC and made from similar raw material. For the first time, these axes give evidence of long-distance (about 800 km) contacts between northeastern Italy and Central Europe during the Neolithic
A metabasite shaft-hole axe from Grotta Azzurra di Samatorza (Trieste Karst): first evidence of connections between northeastern Italy and Central Europe during Neolithic
No full textIMA 2010; 20th General Meeting of the International Mineralogical Association - 21 -27 August 2010
Budapest, Hungar
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
Petrographic and geochemical comparison between the Copper Age "Ljubljana type" axes and similar lithotypes from Eisenkappler Diabaszug complex (southern Austria)
No full textThe petrographic and geochemical features of “Ljubljana type” axes (including Lt1-3 groups), one of the largest assemblage of Copper Age stone artefacts in the Caput Adriae region, have been compared to rocks specifically sampled from the Eisenkappler Diabaszug complex (southern Austria), recently considered as the most probable provenance area. Both the axes and the geological samples show similar mineralogical and petrographic features and are characterized by a common OIB-like signature, metamorphic and spilitization features. The collected data confirm that the Lt3 group originates from one outcrop located in the eastern part of the complex while the precise provenance of the Lt1-2 axes is still to be identified in the same geological area
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