31 research outputs found
Ancient DNA reveals admixture history and endogamy in the prehistoric Aegean (advance online)
The Neolithic and Bronze Ages were highly transformative periods forthe genetic history of Europe but for the Aegeanâa region fundamentalto Europeâs prehistoryâthe biological dimensions of cultural transitionshave been elucidated only to a limited extent so far. We have analysed newlygenerated genome-wide data from 102 ancient individuals from Crete, theGreek mainland and the Aegean Islands, spanning from the Neolithic tothe Iron Age. We found that the early farmers from Crete shared the sameancestry as other contemporaneous Neolithic Aegeans. In contrast, the endof the Neolithic period and the following Early Bronze Age were marked byâeasternâ gene flow, which was predominantly of Anatolian origin in Crete.Confirming previous findings for additional Central/Eastern Europeanancestry in the Greek mainland by the Middle Bronze Age, we additionallyshow that such genetic signatures appeared in Crete gradually from theseventeenth to twelfth centuries bc, a period when the influence of themainland over the island intensified. Biological and cultural connectednesswithin the Aegean is also supported by the finding of consanguineousendogamy practiced at high frequencies, unprecedented in the globalancient DNA record. Our results highlight the potential of archaeogenomicapproaches in the Aegean for unravelling the interplay of genetic admixture,marital and other cultural practice
Nothing Lasts Forever: Environmental Discourses on the Collapse of Past Societies
The study of the collapse of past societies raises many questions for the theory and practice of archaeology. Interest in collapse extends as well into the natural sciences and environmental and sustainability policy. Despite a range of approaches to collapse, the predominant paradigm is environmental collapse, which I argue obscures recognition of the dynamic role of social processes that lie at the heart of human communities. These environmental discourses, together with confusion over terminology and the concepts of collapse, have created widespread aporia about collapse and resulted in the creation of mixed messages about complex historical and social processes
Dynamics and Control During Start-up of Energy Integrated Distillation Column
To advocate the usage of process integration in industrial practice, it is important to be able to guarantee not only robust control during near steady state operation, but also to provide procedures for generating fast and reliable start-up sequences. This contribution concentrates on describing a systematic procedure for development of plant start-up sequences. The basis for the start-up procedure development is available qualitative process knowledge. Application of the start-up sequence generation procedure is demonstrated upon an energy integrated distillation plant. This plant illustrates some of the inherent effects of process integration upon a start-up procedure. In particular the effect of energy recycle upon the possible start-up sequence, and the effect of using an actuator for control purposes, i.e. the heat pump, which in itself requires significant start-up time. The experimental application of a generated start-up sequence illustrates that safe and reliable startups are..