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Peyote, a psychoactive cactus native to the Chihuahuan Desert, has been preserved from excavations at only two archaeological sites: Shumla Caves in the Lower Pecos region of southwest Texas and shelter CM-79 near Cuatro Ciénegas in Coahuila, Mexico. We determined three indistinguishable radiocarbon ages of 5160 ± 45, 5200 ± 35, and 5210 ± 35 14C years BP, yielding a mean age of 5195 ± 20 14C years BP for the three specimens from Shumla Caves. For one of the Cuatro Ciénegas specimens we obtained the first direct radiocarbon date of 835 ± 35 14C years BP. This study demonstrates the use of peyote by inhabitants of the Lower Pecos region of the Chihuahuan Desert about 6000 calendar years ago, and confirms its use by inhabitants of the Cuatro Ciénegas region of the Chihuahuan Desert in Late Prehistoric times. The Shumla Caves' specimens are composed of an aggregate of ground peyote mixed with other plant material, i.e., they appear to be manufactured peyote effigies, and are definitely not intact peyote buttons.  相似文献   
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Explaining how the monumental statues (moai) of Easter Island were transported has remained open to debate and speculation, including their resource expenditures and role in deforestation. Archaeological evidence including analysis of moai variability, particularly those abandoned along ancient roads, indicates transport was achieved in a vertical position. To test this proposition we constructed a precise three-dimensional 4.35 metric ton replica of an actual statue and demonstrate how positioning the center of mass allowed it to fall forward and rock from side to side causing it to ‘walk.’ Our experiments reveal how the statue form was engineered for efficient transport by a small number of individuals.  相似文献   
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Palaeodietary studies typically focus on the analysis of bone collagen due to the limited availability of plant remains. Isotopic analysis of plant remains, however, allow for a more extensive consideration of the contribution of plants to the human diet and can potentially provide information about the environment in which the crops were grown. This paper reports the results of carbon and nitrogen isotope analyses performed on charred barley and wheat grains recovered from pits within Danebury Iron Age hillfort. To the best of our knowledge, this is the first Iron Age site in Britain from which charred grains have been isotopically analysed. Our results suggest that cereals found at the hillfort were grown in several different environmental contexts. The isotope data demonstrate that the herbivores were not consuming a diet primarily based on grains as the δ15N values of the grains are very similar to those of the herbivores. Palaeodietary investigations typically assume that humans eating plant protein only would have the same δ15N value as the local herbivores. This assumption is clearly invalid at Danebury, where the humans and animals appear to have consumed either different parts of the same plants or different plants. Researchers typically interpret high differences between human and animal δ15N values as indicative of diets high in animal protein, however where major plant resources have δ15N values similar to those of the herbivores our ability to distinguish between plant and animal sources of protein in the diet is limited. Our research has demonstrated that whenever possible it is desirable to measure the isotopic signatures of potential major plant resources in order to understand past subsistence strategies.  相似文献   
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This study investigates bone stable isotopes from pigs from medieval York, to characterise the pigs' diet and to explore their contribution to isotopic values from contemporary human bones. Pig bones from the Swinegate (N?=?9) and Coppergate (N?=?14) sites were used for carbon and nitrogen stable isotope analysis to test the hypothesis that the majority of pigs in medieval York were yard-kept and fed on scraps and fish waste, elevating their nitrogen ratios. The results show that the Swinegate and Coppergate pigs gave nitrogen isotope values similar to contemporary sheep and therefore that animal protein made little or no dietary contribution. One sample showed C and N results consistent with more animal protein in the diet, and we propose that this could have been a yard-kept pig consuming human refuse. The majority of the data indicate that the pigs were eating a largely herbivorous diet and that pigs in medieval York may have been raised in rural or woodland locations rather than in the city.  相似文献   
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The industrial structures of Quebec and Ontario differ, with labour-intensive industries prevalent in Quebec, capital-intensive in Ontario. Existing explanations of this structural divergence are complemented by a trade theory interpretation based on the Heckscher-Ohlin hypothesis. Analysis based on the twenty major industrial categories of the sic yields insignificant results, but when resource and market-oriented industries are excluded, significant results are obtained. Trade between Quebec and Ontario also conforms with the theory. The results suggest that it is to Quebec's advantage to continue trading freely with the rest of Canada.
Les structures industrielles au Quebec et en Ontario sont differentes: les industries de main d'truvre predominent au Quebec et celles capital eleve predominent en Ontario. Aux explications actuelles de cette divergence structurelle s'ajoute celle d'une theorie des echanges basee sur I'hypothese HeckscherOhlin. Une analyse basee sur les vingt premieres categories du recensement industriel rev& des resultats peu probants. On obtient cependant des resultats significatifs lorsque I'on exclue de cette analyse les industries dont la localisation est liee aux marches ou a la prksence de tessources naturelles. Le commerce entre le Quebec et I'Ontario est aussi en accord avec cette theorie. Ces resultats suggerent qu'il est avantageux pour le Quebec de poursuivre une politique de libre echange avec la reste du Canada.  相似文献   
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