1,948 research outputs found
Urbanization, socio-economic changes and population growth in Brazil: dietary shifts and environmental implications.
Population growth, economic globalization, improving living standards and urbanization are causing important changes in the global food system and modifying the dietary habits in many parts of the world (Molden, 2007; Godfray et al., 2010). The nutritional transition (linked to the development of countries and the increasing wealth of its population) implies a shift away from traditional staple food such as roots and tuber vegetables and a rise in consumption of meat and milk products, refined and processed foods, as well as sugars, oils and fats (Ambler-Edwards et al., 2009). The contemporary food system puts significant pressure on natural resources, especially on land and water, because the growing food demand pushes the agricultural frontier beyond, causing large impacts on ecosystems (Ambler-Edwards et al. 2009: 11-18). Also, the trend towards richer diets in animal proteins and processed food adds further pressure on the environment, since it requires larger amount of water and land to be produced (Allan, 2011; Mekonnen and Hoekstra, 2012)
A technological analysis of non-flaked stone tools in Olduvai Beds I & II. Stressing the relevance of percussion activities in the African Lower Pleistocene
Dans cette contribution, les activités de percussion des sites des Beds I et II d´Olduvai sont réexaminées à partir de l’étude des assemblages recueillis par Mary Leakey dans les années 1960. Tant les types de percussion reconnus à Olduvai que les caractéristiques principales des enclumes, des percuteurs et des produits obtenus ont été systématisés. Il est ainsi possible d´évaluer l´importance des activités de percussion par rapport aux opérations de taille dans certains assemblages, ce qui fournit des informations significatives concernant la fonction des sites en question.This paper studies the percussive technology in some of the Olduvai Bed I and II sites excavated by Mary Leakey in the 1960s. Types of percussion recorded at Olduvai and the most relevant features of the anvils, hammerstones and by-products are systematized. The importance of percussion activities versus knapping processes in some of the Olduvai assemblages is discussed, which provides insights on the functionality of early archaeological sites
A technological analysis of non-flaked stone tools in Olduvai Beds I & II. Stressing the relevance of percussion activities in the African Lower Pleistocene
Dans cette contribution, les activités de percussion des sites des Beds I et II d´Olduvai sont réexaminées à partir de l’étude des assemblages recueillis par Mary Leakey dans les années 1960. Tant les types de percussion reconnus à Olduvai que les caractéristiques principales des enclumes, des percuteurs et des produits obtenus ont été systématisés. Il est ainsi possible d´évaluer l´importance des activités de percussion par rapport aux opérations de taille dans certains assemblages, ce qui fournit des informations significatives concernant la fonction des sites en question.This paper studies the percussive technology in some of the Olduvai Bed I and II sites excavated by Mary Leakey in the 1960s. Types of percussion recorded at Olduvai and the most relevant features of the anvils, hammerstones and by-products are systematized. The importance of percussion activities versus knapping processes in some of the Olduvai assemblages is discussed, which provides insights on the functionality of early archaeological sites
Archaeological surveys in Tendaho (Lower Awash, Afar Regional State, Ethiopia)
Altres ajuts: BICAEHFID/832980Este trabajo presenta las prospecciones arqueolĂłgicas en la zona de Tendaho (Lower Awash, Triángulo de Afar en EtiopĂa), destinadas a la documentaciĂłn de yacimientos plio-pleistocenos en peligro de desaparecer por la construcciĂłn de una presa. Presentamos tambiĂ©n una modelizaciĂłn en SIG de la extensiĂłn de la presa y el área potencial afectada, y valoramos la importancia de los materiales documentados durante las prospecciones.This paper presents the archaeological surveys conducted in the Tendaho area (Lower Awash, Afar Triangle in Ethiopia), aimed at documenting Plio-Pleistocene sites endangered by the construction of a dam. We also introduce a GIS model of the area affected by the dam, and evaluate the relevance of materials documented during our surveys
La tecnologĂa lĂtica del 'Complejo ST' de Peninj (Lago Natron, Tanzania) : análisis de un conjunto del Olduvayense africano
En este trabajo se presenta un análisis sistemático de los materiales lĂticos hasta ahora estudiados en el Complejo ST de Peninj, en el lago Natron (Tanzania). Este complejo está constituido por un grupo de 11 yacimientos arqueolĂłgicos muy prĂłximos topográficamente y situados en la misma posiciĂłn estratigráfica, por encima de la Toba 1 en las Upper Sandy Cáliz (Arcillas Arenosas Superiores) de la FormaciĂłn Humbu de Peninj, cuya cronologĂa se estima entre los 1,6-1,4 ma. Desde una perspectiva tecnolĂłgica, se estudiarán conjuntamente los objetos lĂticos recuperados en cada uno de estos yacimientos, incidiendo en la relevancia de las conclusiones obtenidas para el conocimiento del Olduvayense africanoIn this work a sistematic analysis of the lithic materials from the ST Site Complex (Lake Natron, Tanzania) is presented. This complex is composed of a cluster of eleven archaeological sites, which share a topographic proximity and the same stratigraphic position. They are located above Tuff 1 in the Upper Sandy Clays of the Humbu Formation of Peninj, dated around 1,6-1,4 ma. Lithic artefacts from each archaeological site will be analysed together from a technological perspective, focusing on the relevance of the conclusions obtained for knowledge of the African Oldowa
Diversidad y continuidad de los sistemas tĂ©cnicos del PaleolĂtico Medio en los Pirineos sur-orientales
En aquest article es presenta una sĂntesi metodològica sobre la tecnologia utilitzada en l’elaboraciĂł dels productes de talla al llarg del paleolĂtic mitjĂ , a la vegada que es duu a terme una anĂ lisi comparativa dels mètodes de talla documentats en els nivells N10 de la Roca dels Bous i en les unitats UA3, S5, S6 i S7 de l’Estret de TragĂł. Aquests assentaments, ubicats en els Pre-pirineus orientals (Noguera, Lleida), presenten ocupacions musterianes amb cronologies de l’MIS5 en els nivells mĂ©s antics de TragĂł i de l’MIS3 amb N10 de la Roca dels Bous i els nivells recents de TragĂł. En ambdĂłs jaciments i independentment de la cronologia dels nivells estudiats, s’hi detecta una variabilitat i una coexistència de mètodes de talla agrupats en estratègies expeditives i estructurades. D’altra banda, en tots els conjunts analitzats es documenten intensos processos de reducciĂł dels nuclis, la qual cosa no es pot relacionar amb la manca de matèries primeres. Els patrons tecnoeconòmics que es detecten en els nivells mĂ©s antics de TragĂł persisteixen en les ocupacions mĂ©s recents d’aquest mateix jaciment, aixĂ com en el nivell N10 de la Roca dels Bous. L’estabilitat al llarg del temps d’aquests comportaments ens porta a suggerir la continuĂŻtat de determinats elements tecnocognitius dels neandertals als Pre-Pirineus sud-orientals.In this paper, we present a methodological approach in order to define general trends in the Middle Palaeolithic technical systems. This approach has been applied to level N10 of Roca dels Bous site and levels UA3, S5, S6 and S7 of Estret de TragĂł site. These rockshelters are located in the South-eastern Pre-Pyrenees (Noguera, Catalonia, Spain) and they were occupied in the MIS5 —TragĂł UA3—, and MIS3 —S7, S6 and S5 in TragĂł and Roca dels Bous level N10—. The analysis of these assemblages shows both a certain degree of technical variability and the coexistence of «expedient» and structured knapping methods. These assemblages also share anintense core-reduction pattern not related to the scarcity of raw material. This techno-economic pattern ha been identified in all the leves of TragĂł and in the Roca dels Bous one. We propose that this stability in technical behaviour can be interpreted in terms of a long term continuity of the techno-cognitive sphere of the South-eastern Prepyrenean Neanderthals.En este artĂculo se presenta una sĂntesis metodolĂłgica sobre la tecnologĂa empleada en la elaboraciĂłn de los productos de talla a lo largo del PaleolĂtico Medio de los Pirineos Orientales, a la vez que se lleva a cabo un análisis comparativo de los mĂ©todos de talla documentados en los niveles N10 de la Roca dels Bous y en las unidades UA3, S5, S6 y S7 de Estret de TragĂł. Estos asentamientos, ubicados en los Pre-Pirineos Orientales (Noguera, Lleida), presentan ocupaciones musterienses con cronologĂas del MIS5 en los niveles más antiguos de TragĂł y del MIS3 tanto en N10 de la Roca dels Bous como en los niveles más recientes de TragĂł. En ambos yacimientos e independientemente de la cronologĂa de los niveles estudiados, se detecta la coexistencia de distintos mĂ©todos de talla agrupados en estrategias de talla expeditivas y estructuradas. Por otro lado, en todos los conjuntos analizados se documentan intensos procesos de reducciĂłn de los nĂşcleos, lo cual no se puede relacionar con la escasez de materias primas. Los patrones tecno-econĂłmicos que se detectan en los niveles más antiguos de TragĂł persisten en las ocupaciones más recientes de este mismo yacimiento, asĂ como en el nivel N10 de la Roca dels Bous. La estabilidad en el tiempo de estos comportamientos permite sugerir la continuidad de elementos tecno-cognitivos en los neandertales en el Pre-Pirineo sur-oriental
The Giardial Arginine Deiminase Participates in Giardia-Host Immunomodulation in a Structure-Dependent Fashion via Toll-like Receptors
Beyond the problem in public health that protist-generated diseases represent, understanding the variety of mechanisms used by these parasites to interact with the human immune system is of biological and medical relevance. Giardia lamblia is an early divergent eukaryotic microorganism showing remarkable pathogenic strategies for evading the immune system of vertebrates. Among various multifunctional proteins in Giardia, arginine deiminase is considered an enzyme that plays multiple regulatory roles during the life cycle of this parasite. One of its most important roles is the crosstalk between the parasite and host. Such a molecular “chat” is mediated in human cells by membrane receptors called Toll-like receptors (TLRs). Here, we studied the importance of the 3D structure of giardial arginine deiminase (GlADI) to immunomodulate the human immune response through TLRs. We demonstrated the direct effect of GlADI on human TLR signaling. We predicted its mode of interaction with TLRs two and four by using the AlphaFold-predicted structure of GlADI and molecular docking. Furthermore, we showed that the immunomodulatory capacity of this virulent factor of Giardia depends on the maintenance of its 3D structure. Finally, we also showed the influence of this enzyme to exert specific responses on infant-like dendritic cells
Change and stasis in the Iberian Middle Paleolithic. : Considerations on the significance of Mousterian technological variability
The European Mousterian has traditionally been portrayed as a long period of technological stasis as opposed to the technotypological dynamism of Upper Paleolithic cultures. The classic debate on Mousterian variability explained interassemblage differences either by ethnic, cultural, functional, and chronological or by paleoenvironmental causes, but variability was based on typological considerations. Recently, technological factors have been introduced in discussions over time trends and geographic differences in the Mousterian. This paper will address the topic by reviewing technological strategies in the Iberian Middle Paleolithic. Three sites from northeastern Spain are chosen as a case study to address the existence of directional patterns in the Iberian Mousterian. We conclude that albeit diachronic variability exists, it does not show patterning, which suggests stochastic variation rather than directional change in the technological strategies of Iberian Neanderthal
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