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- Harris, Alison, 1982-
(författare)
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Palaeodiet and Infant Feeding in Coastal Arctic Settlements : Insights from stable isotope analysis of bone and dentine collagen and amino acids
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation investigates the day-to-day activities that sustained human societies in the arctic and subarctic environments of North America and Siberia over the past 1500 years. Maintenance activities, such as food preparation, childcare, and the care of domestic animals, are commonly inflected by social identity and can provide insight into the experience of gender among archaeological and historical populations. This PhD combined stable isotope analysis of bulk bone collagen and single amino acids, with ethnographic research and ancient DNA analysis to answer a number of research questions, such as, how can the effects of destructive biomolecular sampling protocols be minimized?; how were sled dogs provisioned across the Arctic?; how can palaeodietary research inform our understanding of social relationships between humans and dogs?; how long were human infants breastfed among Bering Sea hunter-gatherers?The dissertation is comprised of five studies: a review of stable isotope studies of late Holocene Arctic populations; a methodological paper presenting a best practice for the pre-treatment of humic-contaminated bone samples, and three bioarchaeological applications that variously employ stable isotope analysis of bulk bone collagen, DNA analysis of dog furs, and isotopic analysis of amino acids. The isotopic evidence for dog diets largely corresponds to zooarchaeological and ethnographic evidence for local subsistence practices. Dog bones dating to between the 15th and 19th centuries, from coastal Labrador, Canada, carried a strong marine isotope signature as did dog furs collected during the early 20th century in Greenland, coastal Labrador, and Alaska. Dogs living among reindeer herders in early 20th century Siberia consumed terrestrial protein sources, while those on the Kamchatka Peninsula consumed terrestrial protein supplemented by limited quantities of salmon. Dog provisioning required considerable human labour and was an important structuring component of daily life in the Arctic. The final study presents the first analysis of infant feeding practices among prehistoric hunter-gatherers of the Bering Sea coast. This study uses stable isotope analysis of bulk collagen from dentine increments to show that breastfeeding and weaning practices varied considerably across the sampled group. The novel isotopic analysis of amino acids from dentine suggests those amino acids, such as lysine, that are routed directly from diet to collagen, show promise for distinguishing between the dual influences of diet and systemic stress on the nitrogen isotope values of human proteins.In the thesis summary, I also include a discussion of the ethics of bioarchaeological practice. Indigneous Arctic cultures are frequently the focus of archaeological study in Canada, Scandinavia, the United States, and Russia, but among these regions, the legislation designed to protect Indigenous cultural heritage differs dramatically. In light of the increasing number of bioarchaeological studies conducted in Siberia, I review regional differences in the codes of bioarchaeological practice and, drawing on bioarchaeological research in other international contexts, suggest some possible solutions for future work.
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| 2. |
- Villamayor, Michelle Marie S., et al.
(författare)
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Wafer-sized WS2 monolayer deposition by sputtering
- 2022
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Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3364 .- 2040-3372. ; 14:17, s. 6331-6338
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate that tungsten disulphide (WS2) with thicknesses ranging from monolayer (ML) to several monolayers can be grown on SiO2/Si, Si, and Al2O3 by pulsed direct current-sputtering. The presence of high quality monolayer and multilayered WS2 on the substrates is confirmed by Raman spectroscopy since the peak separations between the A(1g)-E-2g and A(1g)-2LA vibration modes exhibit a gradual increase depending on the number of layers. X-ray diffraction confirms a textured (001) growth of WS2 films. The surface roughness measured with atomic force microscopy is between 1.5 and 3 angstrom for the ML films. The chemical composition WSx (x = 2.03 +/- 0.05) was determined from X-ray Photoelectron Spectroscopy. Transmission electron microscopy was performed on a multilayer film to show the 2D layered structure. A unique method for growing 2D layers directly by sputtering opens up the way for designing 2D materials and batch production of high-uniformity and high-quality (stochiometric, large grain sizes, flatness) WS2 films, which will advance their practical applications in various fields.
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