Population dynamics and socio-spatial organization of the Aurignacian: Scalable quantitative demographic data for western and central Europe.

Demographic estimates are presented for the Aurignacian techno-complex (~42,000 to 33,000 y calBP) and discussed in the context of socio-spatial organization of hunter-gatherer populations. Results of the analytical approach applied estimate a mean of 1,500 persons (upper limit: 3,300; lower limit: 800) for western and central Europe. The temporal and spatial analysis indicates an increase of the population during the Aurignacian as well as marked regional differences in population size and density. Demographic increase and patterns of socio-spatial organization continue during the subsequent early Gravettian period. We introduce the concept of Core Areas and Extended Areas as informed analytical spatial scales, which are evaluated against additional chronological and archaeological data. Lithic raw material transport and personal ornaments serve as correlates for human mobility and connectedness in the interpretative framework of this study. Observed regional differences are set in relation with the new demographic data. Our large-scale approach on Aurignacian population dynamics in Europe suggests that past socio-spatial organization followed socially inherent rules to establish and maintain a functioning social network of extremely low population densities. The data suggest that the network was fully established across Europe during the early phase of the Gravettian, when demographic as well as cultural developments peaked.

Effect of linoleic acids on the release of ß-carotene from carotenoid-producing Saccharomyces cerevisiae into sunflower oil.

In situ extraction is important for highly productive and cost-efficient processes in industrial biotechnology, but it is difficult to establish for intracellularly accumulating carotenoids like ß-carotene. In this study, the organic solvent used in aqueous-organic two-phase media exerted a strong effect on the release of ß-carotene from recombinant yeast cells. The carotenoid-synthesizing Saccharomyces cerevisiae strain YB/I/E was cultivated in two-liquid-phase media with 20% dodecane or 20% sunflower oil. Up to 0.6 µg/ml ß-carotene was released into sunflower oil, but less than 0.1 µg/ml into dodecane, although biocompatibility and solubility of ß-carotene is appropriate for both solvents. Addition of linoleic acid, the main component of sunflower oil, to the dodecane phase increased the amount of ß-carotene released, indicating that linoleic acid is the component responsible for the ß-carotene release into sunflower oil. These findings demonstrate that the effect of the organic solvent should be taken into consideration for further research on in situ extraction of carotenoids.