Palaeolithic chert exploitation in the limestone stretch of the Egyptian Nile Valley

Different raw material procurement strategies are attested in the limestone stretch of the Egyptian Nile Valley. Chert cobbles from Nile terraces or from their derived deposits were generally used. Four main procurement strategies have been recognized. During the Middle Palaeolithic intensive surface collecting was the most common strategy. However, open quarrying techniques involving features such as ditches are also attested. True subterranean mining with vertical shafts and underground galleries was known by the Early Upper Palaeolithic at 35,000 years BP. Extracted nodules were processed at the procurement sites. The study of the reduction strategies has proved valuable in gaining a better understanding of the Palaeolithic sequence of the Egyptian Nile Valley.

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Résumé Différentes stratégies d'obtention de matière première ont été reconnues dans la zone calcaire de la vallée du Nil égyptien. En majorité, ce sont des galets de chert qui ont été utilisés. Les stratégies d'obtention se classent en quatre types. Au Paléolithique Moyen la méthode la plus fréquente était la collection intensive en surface. Mais il y eut aussi une technique d'exploitation en profondeur, à l'aide de tranchées à ciel ouvert. Une véritable extraction minière avec des puits verticaux et des galleries souterraines fut pratiquée dès le début du Paléolithique Supérieur, vers 35.000 BP. Les galets extraits étaient réduits sur les sites d'exploitation mêmes. L'étude des processus de réduction nous a permis de mieux comprendre la séquence paléolithique de la vallée du Nil égyptien.

     

LOCATION AND ENTREPRENEURSHIP: INSIGHTS FROM A SPATIALLY‐EXPLICIT OCCUPATIONAL CHOICE MODEL WITH AN APPLICATION TO CHILE

Occupational choice and heterogeneous managerial ability enter a spatial Dixit‐Stiglitz setting, linking location, wages and regional entrepreneurship rates. Market potential has a positive partial effect and wages a negative partial effect on the regional supply of entrepreneurs, both balancing in equilibrium with endogenous wages. Market potential increases profits, but also the opportunity cost of entrepreneurship. In the long‐run equilibrium with perfect mobility, the cut‐off level of ability determining selection into entrepreneurship will be the same across regions; moreover, regional differences in entrepreneurship rates depend only in differences in average fixed costs of firms. An empirical application is provided for Chile.     

Mapping the audit traces of interdisciplinary collaboration: bridging and blending between choreography and cognitive science

ABSTRACT

Two long-term sci–art research projects are described and positioned in the broader conceptual landscape of interdisciplinary collaboration. Both projects were aimed at understanding and augmenting choreographic decision-making and both were grounded in research conducted within a leading contemporary dance company. In each case, the work drew upon methods and theory from the cognitive sciences, and both had a direct impact on the way in which the company made new work. In the synthesis presented here the concept of an audit trace is introduced. Audit traces identify how specific classes of knowledge are used and transformed not only within the arts or sciences but also when arts practice is informed by science or when arts practice informs science.