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“Victories of Freedom which Humans Achieved by Research in the Foundation of Things”. - This article analyzes the political self-conception of leading representatives of the natural sciences in 19th century Germany. It is argued that the main feature of this self-conception which remained constant over the time consisted in a strong “rationalization-imperative”, i.e. the postulate that state and society have to be reshaped on the basis of natural science. On the other hand, this imperative was put forward in very different forms and with different political content: it shifted from revolutionary aspirations in the period of 1848 to moderate and sometimes even reactionary positions in the last decades of the century.  相似文献   
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Shell beads are well established in the archaeological record of sub-Saharan Africa and appear as early as 75,000 BP; however, most research has focused on ostrich eggshell (OES) and various marine mollusc species. Beads made from various land snails shells (LSS), frequently described as Achatina, also appear to be widespread. Yet tracking their appearance and distribution is difficult because LSS beads are often intentionally or unintentionally lumped with OES beads, there are no directly dated examples, and bead reporting in general is highly variable in the archaeological literature. Nevertheless, Achatina and other potential cases of LSS beads are present at over 80 archaeological sites in at least eight countries, spanning the early Holocene to recent past. Here, we collate published cases and report on several more. We also present a new case from Magubike Rockshelter in southern Tanzania with the first directly dated LSS beads, which we use to illustrate methods for identifying LSS as a raw material. Despite the long history of OES bead production on the continent and the abundance of land snails available throughout the Pleistocene, LSS beads appear only in the late Holocene and are almost exclusively found in Iron Age contexts. We consider possible explanations for the late adoption of land snails as a raw material for beadmaking within the larger context of environmental, economic, and social processes in Holocene Africa. By highlighting the existence of these artifacts, we hope to facilitate more in-depth research on the timing, production, and distribution of LSS beads in African prehistory.  相似文献   
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Professor James Kwesi Anquandah was Ghana’s first archaeologist. He was also the first Ghanaian to become head of the Archaeology Department at the University of Ghana, which was the first archaeology department in sub-Saharan Africa, established in 1951. Dedicating his life to Ghanaian archaeology, particularly during the difficult years in Ghana in the 1980s and early 1990s, Anquandah had a significant impact on the development of archaeology in Ghana. In addition to his research, advisory and curatorial work, Professor Anquandah was instrumental in the training of three generations of Ghanaian archaeologists. During the course of a professional career that spanned nearly six decades, Professor Anquandah made archaeology relevant and accessible to all Ghanaians.  相似文献   
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The period comprising the end of the Early Neolithic and the Middle Neolithic, dated broadly within the fifth millennium cal BC, corresponds to an interval that remains largely unknown in the extreme north-western tip of Africa. This situation contrasts with that of the Early Neolithic, a period characterised by the earliest evidence of the diffusion of a productive economy, cultivated plants and domestic animals. The paucity of data for these later phases can be explained in part by the lack of secure contexts and sequences based on radiocarbon datings of short-lived samples. The current study presents the results of the excavations of El-Khil Caves B and C that yield materials allowing re-evaluation of the chronology of a type of ceramic known as Ashakar ware. The study also identifies two traditions in the northern Moroccan Middle Neolithic. The first is heir to the so-called Impressa Mediterranean ware and rooted in the Cardial Neolithic, while the second is characterised by roulette cord impressions, red slip and tunnel lugs and probably rooted in the region of the Sahara, and has no technological precedents in the study area.  相似文献   
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