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91.
Understanding the nature of the physical properties of lithic raw materials is a pre-requisite for developing more reliable interpretations of use-wear evidence and tool function. We use nanoindentation and use-wear experimentation as a way to measure differences in raw material surface hardness and roughness in order to show that differences in lithic material properties have implications for rates of use-wear accrual.  相似文献   
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In this paper, we consider two different cases of spillover effects: the first is a case where the model does not contain any additional endogenous regressors. Related to this, we give a variance formula that can be used to make inference for estimated spillover effects. In the second case, we extend the discussion of spillover effects to a model containing additional endogenous variables. We suggest approximations to the spillover effects that according to the results of our Monte Carlo experiment are quite accurate. However, our variance formula can not be determined unless the equations of the entire system are known. Suggestions for approximations in this case are left for future research.  相似文献   
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ABSTRACT In this paper, we specify a linear Cliff‐and‐Ord‐type spatial model. The model allows for spatial lags in the dependent variable, the exogenous variables, and disturbances. The innovations in the disturbance process are assumed to be heteroskedastic with an unknown form. We formulate multistep GMM/IV‐type estimation procedures for the parameters of the model. We also give the limiting distributions for our suggested estimators and consistent estimators for their asymptotic variance‐covariance matrices. We conduct a Monte Carlo study to show that the derived large‐sample distribution provides a good approximation to the actual small‐sample distribution of our estimators.  相似文献   
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This article presents a multidisciplinary analysis of a human skull with preserved soft tissue curated by a small museum in Boscastle, Cornwall, UK. The skull lacks a mandible and is coated in a black tar-like substance. Records left by a previous museum curator (now deceased) claimed the skull to be the head of a medieval execution victim. The skull was purportedly recovered from a London church that was destroyed during the Second World War where it had been kept in a carved oak box. If these details are correct, the skull would appear to have been venerated as a relic. The skull and box have been analysed using a range of techniques including computerised tomography, laser scanning, microscopy, infrared spectroscopy and radiocarbon dating. These analyses demonstrated the skull in fact to be that of an Egyptian mummy dating from the Ptolemaic period. Other instances have been noted of parts of Egyptian mummies being presented as European saintly relics, and the ‘Boscastle skull’ would appear to be an example of such. A wider point illustrated by the work presented here is that sufficient application of modern analytical techniques may reveal considerable information regarding human remains which otherwise have little or no provenance. This point strengthens arguments for the retention of such remains by curating institutions.  相似文献   
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