Strontium isotope evidence for human mobility in the Neolithic of northern Greece

Strontium isotope ratios are widely used in archaeology to differentiate between local and non-local populations. Herein, strontium isotope ratios of 36 human tooth enamels from seven archaeological sites spanning the Early to Late Neolithic of northern Greece (7th–5th millennia B.C.E.) were analysed with the aim of providing new information relating to the movement of humans across the region. Local bioavailable 87Sr/86Sr signals were established using tooth enamel from 26 domestic animals from the same Neolithic sites. 87Sr/86Sr values of faunal enamel correlate well with predicted strontium isotope ratios of the local geology. This is consistent with animal management occurring at a local level, although at Late Neolithic sites strontium isotope values became more varied, potentially indicating changing herding practices. The strontium isotope analysis of human tooth enamel likewise suggests limited population movement within the Neolithic of northern Greece. Almost all individuals sampled exhibited 87Sr/86Sr values consistent with having spent their early life (during the period of tooth mineralisation) in the local area, although movement could have occurred between isotopically homo- geneous areas. The strontium isotope ratios of only three individuals lay outside of the local bioavailable 87Sr/86Sr range and these individuals are interpreted as having spent their early lives in a region with a more radiogenic biologically available 87Sr/86Sr. Mobility patterns determined using Sr isotope analysis supports the current evidence for movement and exchange observed through studies of pottery circulation. Suggesting limited movement in the Early and Middle Neolithic and greater movement in the Late Neolithic

A bottom-up view of food surplus: using stable carbon and nitrogen isotope analysis to investigate agricultural strategies and diet at Bronze Age Archontiko and Thessaloniki Toumba, northern Greece

We use stable isotope analysis of crop, faunal and human remains to investigate agricultural strategies and diet at EBA-LBA Archontiko and MBA-LBA Thessaloniki Toumba. Crop production strategies varied between settlements, phases and species; flexibility is also apparent within the crop stores of individual houses. Escalating manuring intensity at LBA Thessaloniki Toumba coincides with large co-residential ‘blocks’ geared towards hoarding of agricultural surpluses, spectacularly preserved by fire at nearby LBA Assiros Toumba. Faunal isotope values reflect a range of feeding strategies, including probable herding of cattle on C4-rich coastal salt marshes, evident at Archontiko through to the LBA alongside bulk cockle harvesting. Palaeodietary analysis of LBA humans at Thessaloniki Toumba indicates that C3 crops represent the only plausible staples. Millet was a minor food but may have played a particular role in the sub-adult diet. Meat probably featured in supra-household food sharing and hospitality, associated with Mycenaean-style tableware in the LBA

Quenching of excited chlorophyll A in vivo by nitrobenzene.

Nitrobenzene exerts a dual effect on the excitation of chlorophyll a(Chl a) in vivo. (a) A 3(3,4-dichlorophenyl)-1,1-dimethylurea-inhibited quenching that manifests as a partial inhibition of variable chloroplast fluorescence and of 2,6-dichlorophenol indophenol (DCPIP) photoreduction and saturates at ca. 5-10 muM. Since nitrobenzene is not a Hill oxidant, this effect is attributed to a catalyzed back flow of electrons from intersystem intermediates to pre-photosystem II oxidants. (b) A direct quenching of the excited Chl a in vivo. This effect has a threshold of ca. 100 muM nitrobenzene; at higher concentrations it leads to almost complete suppression of chloroplast fluorescence and DCPIP photoreduction. Tris-washed chloroplast enriched in the photosystem II reaction center species Z+Q- and ZQ- are nearly four times more sensitive to nitrobenzene quenching than those enriched in Z+Q. On the other hand, normal chloroplasts are about 10 to the fourth times more sensitive. Hence, it is argued that the extreme sensitivity of normal chloroplast fluorescence is not due to a preferential association of nitrobenzene with a particular redox species of the reaction center

From texts to teeth: A multi-isotope study of sheep and goat herding practices in the Late Bronze Age (‘Mycenaean’) polity of Knossos, Crete

Linear B administrative documents of the late second millennium BC from urban Knossos, Crete, reveal that spatially extensive and centrally monitored sheep flocks and wool production played a fundamental role in Mycenaean palatial economy. Here we employ multi-isotope (δ13C, δ18O, 87Sr/86Sr) analysis of sequentially sampled sheep and goat tooth enamel bioapatite to explore life histories of animals consumed at Knossos. Interpretation of isotopic results incorporates new baseline data on 87Sr/86Sr ratios of bioavailable Sr from modern Cretan plants collected in relevant zones. Results reveal a variety of herding regimes, including seasonal (‘wet/winter’ to ‘dry/summer’) vertical movement of sheep from lowland to highland locations, more restricted mobility for goats in lowland to mid-altitude territories, possible input of fodder to goat diet, and exploitation of a range of plant ecosystems. Results broadly match documentary evidence and ethnographic/ecological expectations for sheep and goat herding at varying scales and underline the role of Knossos in mobilising resources from a range of herding systems and territories

From texts to teeth: A multi-isotope study of sheep and goat herding practices in the Late Bronze Age (‘Mycenaean’) polity of Knossos, Crete

Linear B administrative documents of the late second millennium BC from urban Knossos, Crete, reveal that spatially extensive and centrally monitored sheep flocks and wool production played a fundamental role in Mycenaean palatial economy. Here we employ multi-isotope (δ13C, δ18O, 87Sr/86Sr) analysis of sequentially sampled sheep and goat tooth enamel bioapatite to explore life histories of animals consumed at Knossos. Interpretation of isotopic results incorporates new baseline data on 87Sr/86Sr ratios of bioavailable Sr from modern Cretan plants collected in relevant zones. Results reveal a variety of herding regimes, including seasonal (‘wet/winter’ to ‘dry/summer’) vertical movement of sheep from lowland to highland locations, more restricted mobility for goats in lowland to mid-altitude territories, possible input of fodder to goat diet, and exploitation of a range of plant ecosystems. Results broadly match documentary evidence and ethnographic/ecological expectations for sheep and goat herding at varying scales and underline the role of Knossos in mobilising resources from a range of herding systems and territories

Bioinspired rational design of bi-material 3D printed soft-hard interfaces

Durable interfacing of hard and soft materials is a major design challenge caused by the ensuing stress concentrations. In nature, soft-hard interfaces exhibit remarkable mechanical performance, with failures rarely happening at the interface. Here, we mimic the strategies observed in nature to design efficient soft-hard interfaces. We base our geometrical designs on triply periodic minimal surfaces (i.e., Octo, Diamond, and Gyroid), collagen-like triple helices, and randomly distributed particles. A combination of computational simulations and experimental techniques, including uniaxial tensile and quad-lap shear tests, are used to characterize the mechanical performance of the interfaces. Our analyses suggest that smooth interdigitated connections, compliant gradient transitions, and either decreasing or constraining strain concentrations lead to simultaneously strong and tough interfaces. We generate additional interfaces where the abovementioned toughening mechanisms work synergistically to create soft-hard interfaces with strengths approaching the upper achievable limit and enhancing toughness values by 50%, as compared to the control group.Biomaterials & Tissue BiomechanicsMechatronic Desig