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Scavenger birds can feed on large- to small-sized vertebrates and may contribute in the formation of archaeological sites. To evaluate the modifications and dispersal patterns of bones produced by New World vulture and caracara from Northwestern Patagonia, samples of adult sheep, young sheep, and hare carcasses were offered and subsequently analyzed. New World vultures and caracaras quickly fed on the samples. Taphonomic and bone dispersal patterns suggest two types of accumulations: (1) open-air sites with large and medium-sized vertebrates represented by complete, fractured, scratched, notched, and punctured elements and (2) rock shelter or cave sites dominated by small vertebrates represented by broken, corroded, fractured, and digested elements.  相似文献   
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Urban sprawl has a major impact on the environment, public health and the socio-economic evolution of cities. The causes are numerous, being mainly related to the generalized use of the automobile in modern cities. Urban sprawl has been especially relevant in US cities since the 1950s, rapidly spreading to other cities in the rest of the world. This paper studies the case of Spain using recent data. Spanish cities have grown rapidly over the 90s and 2000s. The country has completed the process of urbanization and has suffered the effects of a major real estate bubble. In this context, we are interested in measuring and explaining where and why urban sprawl has appeared in Spanish cities. Digital mapping carried out around the year 2000 providing full coverage of Spain is used to calculate an Urban Sprawl Index. It is applied to all urban areas and municipalities throughout the country, providing an objective, comparable measurement of sprawl and identifying which areas are most affected by this phenomenon. A second stage of analysis is conducted in an attempt to explain the causes of the differences in sprawl among Spanish cities with a regression model based on the literature. We have found that the cases most affected by sprawl are the latest urban developments on the Mediterranean coast as well as certain areas in the vicinity of large cities: the mountains to the north of Madrid and the coastline near Barcelona and Valencia. In some cases, urban sprawl is starting to become a problem for the environment and urban sustainability, with important consequences for the future evolution of the affected cities.  相似文献   
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If there is one piece of the Castro culture goldwork that stands out above the rest, it is the set of figurative gold diadem‐belt fragments from Moñes (Piloña, Asturias, Spain). Its uniqueness lies in its combination of local technological tradition with exogenous practices, like figurative representation. The figures that appear are armed characters, occasionally on horseback, and sometimes zoomorphic in appearance (especially as bird‐men), together with different kinds of animals, especially those from an aquatic environment. This iconography has been interpreted as emphasizing the warlike character of Celtic symbolism as expressed through an aquatic funerary ritual. My argument here, however, provides an alternative interpretation based on a context of dramatic social change, which warranted the reformulation of creation mythology such as that depicted on the diadem‐belt. This context must be viewed in relation to different social responses which developed during the first century BC, both before and immediately after the Roman conquest.  相似文献   
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A new interpretation of early stone-tool use by hominins at Olduvai depicts them as involved in battering activities (using pounding tools) rather than making cutting butchering tools as is commonly inferred in most other Plio-Pleistocene sites where lithics appear associated to faunal remains. The bulk of this interpretation is based on the recognition of the stigma of percussion activities in anvils and detached by-products. Renewed excavations at BK after more than half a century of the beginning of the digging at the site by M. Leakey have produced a new and unbiased lithic assemblage. The taphonomic study of the faunal assemblage has shown that BK is an anthropogenic site where carcass butchery practices were repeatedly performed over a vast amount of time. The present analysis of the lithic artefacts supports this interpretation by showing that the obtainment of flakes was the principal aim in stone knapping. We argue that a number of technical traits observed in the lithic collection of BK can be best interpreted as the result of bipolar loading rather than the by-products of battering activities. Since BK has provided the second largest collection of hominid-modified bones from Olduvai, it is concluded that detached pieces produced in the course of bipolar reduction might have played an active role in bone modification and that active rather than passive percussion behaviors might have been responsible for the formation of the lithic assemblage. The functionality of the Oldowan stone tools are discussed under the light of the new study.  相似文献   
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In recent years, there has been a growing interest in the problems caused by the existence of instability in cross-sectional regressions. The results about local autocorrelation measures are part of this debate, as are the proposals concerning the concept of geographically weighted regressions. This article also deals with the problem of stability (or the lack thereof), but focusing the discussion on the supposition of constancy in the parameter of spatial dependence. In most cases, this assumption is treated, with the risks that this involves, as a maintained hypothesis, which should be ascertained before continuing with the modeling exercise. In the article, we present a simple heterogeneity test for this type of parameters, based on the Lagrange Multiplier principle. To illustrate its use, we take the distribution of per capita income among the European regions as our discussion case. According to our results, there are clear signs of structural breaks in the spatial distribution of this variable and the scale factor and the autocorrelation coefficient appear to be principal actors.  相似文献   
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