67 research outputs found

    Multiproxy paleodietary reconstruction using stable isotopes and starch analysis: the case of the archaeological site of Playa del Mango, Granma, Cuba

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    Paleoethnobotanical and stable isotope studies have demonstrated that the indigenous groups that populated the Antilles, traditionally understood as dependent exclusively on wild resources, cultivated and consumed both C3 and C4 plants even before the arrival of the ceramic-bearing Arawak groups. However, the relative importance of cultigens and the differential use of plants, especially maize, between populations and individuals remains un-known. In this paper we combined the analysis of stable isotopes (delta 15N, delta 13Cco, delta 13Cen, delta 13Cap, delta 34S) of 27 in-dividuals from the archaeological site of Playa del Mango, Cuba with the identification of starch grains in dental calculus. The stable isotope results indicate that the sampled population had a 70:30 C3/C4 diet, where at least 65 % was based on C3 protein. Starches from C3 (e.g., Marantaceae, Ipomoea batatas) and C4 plants (Zea mays) were found in similar proportions (50:50). These results support that the lack or abundance of starch grains cannot be used to infer directly the frequency at which C3 and C4 plants were consumed within a small popu-lation. Statistically significant differences between females and males in the carbon isotope composition of diet, and its energy portion, suggests a differential consumption of plants by sex. Playa del Mango individual diets were statistically different from those of coeval sites, supporting our previous findings that groups with different dietary traditions concurrently inhabited Cuba in precolonial times. The study demonstrates the power of combined use of stable isotope models, and starch analysis, to provide a more nuanced reconstruction of dietary practices in past human populations.Archaeological science

    Operation 3D Printers Renishaw AM400 for 3D Printing by Method SLM

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    BYRTUS, R. Obsluha 3D tiskárny Renishaw AM400 pro 3D tisk metodou SLM: Bakalářská práce. Ostrava: VŠB – Technická univerzita Ostrava, Fakulta strojní, Katedra obrábění, montáže a strojírenské metrologie, 2017 47s. Vedoucí práce: Ing. Marek Pagáč, Ph.D. Hlavní náplň bakalářské práce spočívala v provedení rešerše všech dostupných metod aditivní výroby a vytvoření uceleného postupu procesu stavby metodou SLM na zařízení Renishaw AM400 za použití korozivzdorného práškového kovu AISI 316L. Teoretická část se zabývala teorii 3D tisku, představením jednotlivých metod tisku a systémů. Dále byla představena samotná metoda selektivního laserového tavení kovů, specifikace práškových kovů a 3D tiskárna na kov. Praktická část je věnována obsluze stroje, jeho kalibrací a činnostem potřebným k zahájení a dokončení tisku.BYRTUS, R. Operation 3D Printers Renishaw AM400 for 3D Printing by Method SLM: Bachelor thesis, Ostrava: VŠB – Technical University of Ostrava, Faculty of Mechanical Engineering, Department of Machining, Assembly and Engineering Metrology, 2017 47s. Thesis head: Ing. Marek Pagáč, Ph.D. The main aim of the bachelor thesis was to investigate all available methods of additional production and to create a complex process of the SLM method of the Renishaw AM400 using a stainless steel AISI 316L powder. The theoretical part deals with the theory of 3D printing, introducing the individual printing methods and systems. In addition, the method of selective laser metal melting, the specification of powder metals and the 3D metal printer were introduced. The practical part is devoted to machine operation, calibration and activities required to initiate and complete printing.346 - Katedra obrábění, montáže a strojírenské metrologievýborn

    The bashful and the boastful : prestigious leaders and social change in Mesolithic Societies

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    The creation and maintenance of influential leaders and authorities is one of the key themes of archaeological and historical enquiry. However the social dynamics of authorities and leaders in the Mesolithic remains a largely unexplored area of study. The role and influence of authorities can be remarkably different in different situations yet they exist in all societies and in almost all social contexts from playgrounds to parliaments. Here we explore the literature on the dynamics of authority creation, maintenance and contestation in egalitarian societies, and discuss the implications for our interpretation and understanding of the formation of authorities and leaders and changing social relationships within the Mesolithic

    The preburning condition of Chalcolithic cremated human remains from the Perdigoes enclosures (Portugal)

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    The Iberian Chalcolithic displayed a remarkable variety of funerary practices, which has been related to interpopulation differences, intrapopulation social-cultural differences, and complex multistage funerary rituals. Perdigoes, a Chalcolithic set of ditched enclosures, reflects such diversity including a wide array of funerary practices. Among those practices is cremation, which, despite relatively rare, is represented in different structures in Perdigoes. One of these structures (Pit 40) presents an unparalleled high minimum number of individuals (n = 240), contrasting with nearby and coeval structures. In this study, we analyse heat-induced bone changes and other archaeothanatological variables to tentatively assess the preburning condition of the human remains. The results of Pit 40 are also compared with other comparable contexts to assess if this unique context presents further funerary differences relative to those other contexts in, for example, body processing. Our results suggest preferential cremation of fleshed human remains, but burning of at least a minority of skeletonised remains and deposition of possibly unburned remains also likely occurred. Body processing appears to be comparable with that of the cremation contexts of Perdigoes but contrasts with that of another nearby context (Dolmen of Olival da Pega 2b) in which burned bones were also found.Portuguese Foundation for Science and TechnologyPortuguese Foundation for Science and Technology [PEst-OE/SADG/UI0283/2013, POCI-01-0145-FEDER-016766, PTDC/EPH-ARQ/0798/2014, PTDC/IVC-ANT/1201/2014, SFRH/BPD/84268/2012]info:eu-repo/semantics/publishedVersio

    The evolution and changing ecology of the African hominid oral microbiome.

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    The oral microbiome plays key roles in human biology, health, and disease, but little is known about the global diversity, variation, or evolution of this microbial community. To better understand the evolution and changing ecology of the human oral microbiome, we analyzed 124 dental biofilm metagenomes from humans, including Neanderthals and Late Pleistocene to present-day modern humans, chimpanzees, and gorillas, as well as New World howler monkeys for comparison. We find that a core microbiome of primarily biofilm structural taxa has been maintained throughout African hominid evolution, and these microbial groups are also shared with howler monkeys, suggesting that they have been important oral members since before the catarrhine-platyrrhine split ca. 40 Mya. However, community structure and individual microbial phylogenies do not closely reflect host relationships, and the dental biofilms of Homo and chimpanzees are distinguished by major taxonomic and functional differences. Reconstructing oral metagenomes from up to 100 thousand years ago, we show that the microbial profiles of both Neanderthals and modern humans are highly similar, sharing functional adaptations in nutrient metabolism. These include an apparent Homo-specific acquisition of salivary amylase-binding capability by oral streptococci, suggesting microbial coadaptation with host diet. We additionally find evidence of shared genetic diversity in the oral bacteria of Neanderthal and Upper Paleolithic modern humans that is not observed in later modern human populations. Differences in the oral microbiomes of African hominids provide insights into human evolution, the ancestral state of the human microbiome, and a temporal framework for understanding microbial health and disease

    Ten millennia of hepatitis B virus evolution

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    Hepatitis B virus (HBV) has been infecting humans for millennia and remains a global health problem, but its past diversity and dispersal routes are largely unknown. We generated HBV genomic data from 137 Eurasians and Native Americans dated between similar to 10,500 and similar to 400 years ago. We date the most recent common ancestor of all HBV lineages to between similar to 20,000 and 12,000 years ago, with the virus present in European and South American hunter-gatherers during the early Holocene. After the European Neolithic transition, Mesolithic HBV strains were replaced by a lineage likely disseminated by early farmers that prevailed throughout western Eurasia for similar to 4000 years, declining around the end of the 2nd millennium BCE. The only remnant of this prehistoric HBV diversity is the rare genotype G, which appears to have reemerged during the HIV pandemic.Molecular Technology and Informatics for Personalised Medicine and Healt

    Ten millennia of hepatitis B virus evolution

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    Hepatitis B virus (HBV) has been infecting humans for millennia and remains a global health problem, but its past diversity and dispersal routes are largely unknown. We generated HBV genomic data from 137 Eurasians and Native Americans dated between ~10,500 and ~400 years ago. We date the most recent common ancestor of all HBV lineages to between ~20,000 and 12,000 years ago, with the virus present in European and South American hunter-gatherers during the early Holocene. After the European Neolithic transition, Mesolithic HBV strains were replaced by a lineage likely disseminated by early farmers that prevailed throughout western Eurasia for ~4000 years, declining around the end of the 2nd millennium BCE. The only remnant of this prehistoric HBV diversity is the rare genotype G, which appears to have reemerged during the HIV pandemic

    The role of seismic stratigraphy in interpretation

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