NuBIAN: Nubian technology, Behavioural Innovation and Adaptation. New perspectives on Middle Stone Age technological variability and population dynamics

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Electrical impedance spectroscopy for potassium content analysis and botanical origin identification of honey

Publication . Elamine, Youssef; INÁCIO, PEDRO; Miguel, Maria da Graça; Carlier, Jorge; Costa, Maria Clara; Estevinho, Leticia M.; Gomes, Henrique L.

Minerals are reported to dominate the electrical properties of honey and indicate its botanical and geographical origins. In this study, Electrochemical Impedance Spectroscopy (EIS) was used to assess the relation between mineral elements, electrical properties and botanical origin using three honey varieties - Citrus sp., Eucalyptus sp., and Erica sp. These varieties are identified through pollen analysis and market labelling. Flame atomic absorption and emission spectroscopies were used to quantify the concentrations of eight elements (potassium, sodium, calcium, magnesium, manganese, zinc, copper, and iron). Among all the mineral elements, potassium showed a consistent correlation with impedance. The potassium estimation in honey and standard solutions (calibration curve) had similar sensitivities of 153.43 nF/mM and 132.68 nF/mM, respectively. Additionally, the analysis revealed that potassium dominates the mineral composition, with the other species present in minimal quantities. The EIS technique showed high sensitivity to potassium and other ionisable species, making it possible to classify the botanical origin of these three honey types. The EIS technique proved to be both time and cost effective, yielding a classification rate higher than that achieved by analysing mineral composition.

2024-09Journal article

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More than surface finds: nubian levallois core metric variability and site distribution across Africa and Southwest Asia

Publication . Samawi, Osama; Hallinan, Emily

Nubian Levallois cores are currently one of the most debated artefact types in Palaeolithic archaeology. Previous work has focused mainly on the definition and technological characteristics of these cores, with discussion of their distribution framed only in qualitative terms. Here, we present the first quantitative spatial analysis of sites with Nubian Levallois cores across the five global regions where they occur. Using modelled Pleistocene conditions for various bioclimatic and topographic variables, we compare the environmental context of 84 sites featuring Nubian cores with 81 contemporaneous sites where they are absent. Metric analysis of cores from 14 new and previously published sites offers further insights into technological and behavioural patterns at an inter-regional scale. Our results show that Nubian cores during MIS 5 are present in areas characterised by aridity, complex topography, and high biomass, whereas for MIS 3, only temperature was a significant predictor. Metric results reveal distinct patterns in both space and time, finding the largest and most standardised cores in Southern Arabia during MIS 5, with the smallest cores in MIS 3 Eastern and Southern Africa. We propose that environmental factors were a more significant driver behind the adoption of the Nubian Levallois method than previously acknowledged. Our results provide essential environmental context for future model-testing of Late Pleistocene demography and cultural connectivity during this critical phase of human evolution.

2024-09-11Journal article

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