A carregar...
Projeto de investigação
NuBIAN: Nubian technology, Behavioural Innovation and Adaptation. New perspectives on Middle Stone Age technological variability and population dynamics
Financiador
Autores
Publicações
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.
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.
Quantifying levallois: a 3D geometric morphometric approach to nubian technology
Publication . Hallinan, Emily; Cascalheira, João
Levallois technology, a hallmark of Middle Palaeolithic stone tool manufacture, involves sophisticated core reduction strategies that have major implications for understanding human cognitive and technological evolution. However, traditional methods of analysing Levallois cores often fail to capture the nuanced variability in their morphology. This study introduces a novel application of three-dimensional geometric morphometrics (GM) to quantify the shape variability of Nubian Levallois cores from the Nile Valley and Dhofar regions. By employing this technique, we analysed core surfaces and preferential scar shapes, identifying distinct regional and technological patterns. Our results reveal significant inter-regional differences in core elongation and surface convexity, highlighting the importance of shape-oriented, rather than metric-based, analysis of prepared cores. This new GM approach offers a robust and replicable tool for investigating lithic variability and holds potential for broader applications in Palaeolithic research, enhancing our understanding of human technological adaptations.
Unravelling the deep: assessing the bycatch of deep-sea elasmobranchs in crustacean bottom trawl fisheries in Portugal
Publication . Dias, Ester; Marsili, Tiago; Barkai, Amos; Queiroz, Nuno; Graça Aranha Carvalho Ramos, Sofia; Pires da Rocha, Pedro; Teodosio, Maria
Deep-sea elasmobranchs (DSE) play a crucial role in marine ecosystems. However, they are poorly studied and face threats from overfishing, emphasizing an urgent need for improved scientific information, monitoring, and management strategies to reduce their bycatch. This study aimed to assess DSE bycatch from crustacean bottom trawling in southern Portugal, considering depths above and below 800 m (Regulation 2016/2336). Potential bycatch of deep-sea sharks was evaluated using in situ observations from the months of February and March and extrapolated for the fishing ban period (2017–2022). A total of 1559 specimens belonging to 18 DSE species were collected from 77 hauls between June 2020 and May 2022. Despite trawlers preferences for fishing above 800 m in the South, fishing below 800 m in the Southwest resulted in increased bycatch of DSE, including protected, uncommon, and endangered species such as Deania calceus, Mitsukurina owstoni, and Centroscymnus coelolepis. Furthermore, the areas and depth strata occupied by species like Galeus melastomus and Scymnodon ringens, suggested habitat flexibility, while others showed an apparent preference for specific depths and areas. These findings highlight the complexity of managing DSE populations amidst fishing pressures and depth restrictions. Despite the ban imposed to fishing below 800 m, bottom trawling persisted, leading to a potential elevated bycatch of deep-sea sharks for the months of February and March. This study emphasizes the urgency for improved enforcement of regulations in Portuguese waters and calls for the implementation of effective bycatch mitigation and fisheries management practices to safeguard DSE populations.
Unidades organizacionais
Descrição
Palavras-chave
Contribuidores
Financiadores
Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
CEEC IND4ed
Número da atribuição
2021.00041.CEECIND/CP1672/CT0007