The adoption of pottery into the New World:exploring pottery function and dispersal in Southwest Alaska through organic residue analysis

In this PhD project the first use of pottery by prehistoric peoples in Alaska was researched through lipid residue analysis and isotope analysis. Pottery was first invented by hunter-gatherers in East Asia some 20,000 years ago. Recent research shows that early pottery was often used to process aquatic species. In the (sub)Arctic, pottery was not adopted until 3,000 years ago. The presence of pottery in this extreme environment seems out of place. What drove the adoption of pottery into this region? This research has shown that, much like the earlier pottery in East Asia, Alaskan pottery was mainly used to process aquatic species. An interesting pattern shows differences between the earliest pottery in Alaska, which was used to process salmon, and the later pottery that was used to process sea mammals. This pattern seems to extend to Siberia, where early pottery sites are mainly found along large rivers. It is possible that pottery technology spread along the river systems of Northeast Asia into Alaska. In Alaska the dispersal event was delayed significantly on Kodiak Island, where the technology was only partly adopted at around 500 years ago, and finally terminated with the introduction of Russian cooking kettles during contact times

Something fishy in the Great Lakes?:The reappraisal of early pottery use in north-eastern North America.

Lipid residue analysis has recently been applied to investigate the adoption of pottery by Early Woodland hunter-gatherers in north-eastern North America. Results, however, have proven contradictory, especially regarding the extent towhich early ceramics were used for processing aquatic resources. Here, the authors argue that this inconsistency is due to the use of different analytical procedures and criteria for identifying aquatic organisms, rather than anyactual variations in pottery use. By applying robust analytical criteria and methods to Early Woodland pottery from the Great Lakes region, the authors present evidence supporting their hypothesis that such pottery was indeed used for processing aquatic resource

Investigating the function of prehistoric stone bowls and griddle stones in the Aleutian Islands by lipid residue analysis

The earliest durable cooking technologies found in Alaska are stone bowls and griddle stones recovered from the Aleutian Islands. This article aims to identify the function of these artefacts. Molecular and chemical analyses of carbonised residues found on their surfaces confirm that these artefacts were used to process marine resources. Both artefacts have high lipid content and C:N ratios, suggesting they were used to process oily substances. Stable isotope results of individual lipids suggest that they were used to process different sets of resources within the aquatic spectrum as griddle stones have slightly more 13C-depleted lipids than stone bowls, possibly indicating more variable use. Integration of these results with archaeological and ethnographic data leads us to infer that griddle stones were used for cooking a diversity of aquatic resources, possibly with the addition of plant foods, whereas stone bowls were specifically used to render marine mammal fats. We further hypothesize that a sudden peak in stone bowl frequencies at 4000–3000 cal yr BP was connected to a Neoglacial cold spell bringing sea ice conditions to the Aleutian Islands. This may have led to new subsistence strategies in which the rendering of marine mammal fats played a central role

P12-S Frontotemporal electrode set for ICU bedside cEEG monitoring for comatose patients after cardiac arrest

Background: Electroencephalogram (EEG) patterns within 24 h after cardiac arrest (CA) have shown to reliably predict neurological outcome. The recording set-up may be simplified by using a less extensive electrode set. We compared a 4-channel frontotemporal EEG headband (BrainStatus, Bittium, Oulu, Finland) to a 9-channel Ag-AgCl electrode set.Material and methods: Between July 2018 and January 2019, EEGs were recorded in 22 consecutive adult patients admitted after CA with both electrode sets simultaneously. EEG patterns were assessed visually, corresponding to the guidelines of the American Clinical Neurophysiology Society (ACNS). Five minute epochs at 24 h after CA were scored by three independent EEG readers blinded to clinical data. Final classification was determined by majority vote. To evaluate classification agreement between the electrode sets, confusion matrices and Cohen’s Kappa were used.Results: At 24 h after CA, the background patterns of 21 patients were available. With the 9 electrode set, nine patients had a continuous pattern, two patients had a discontinuous pattern, two patients showed burst-suppression without identical burst, one patient showed burst-suppression with identical bursts, and four patients had a suppressed background pattern. The background pattern of three patients was obscured by artefacts. The agreement for background pattern scoring of the 4 electrode set compared to this 9 electrode set was fair ( = 0.32).Conclusions: Visual classification of EEG patterns in patients with postanoxic coma with a 9-channel Ag-AgCl electrode set cannot be replaced with a 4-channel frontotemporal EEG headband

On Geometric Alignment in Low Doubling Dimension

In real-world, many problems can be formulated as the alignment between two geometric patterns. Previously, a great amount of research focus on the alignment of 2D or 3D patterns, especially in the field of computer vision. Recently, the alignment of geometric patterns in high dimension finds several novel applications, and has attracted more and more attentions. However, the research is still rather limited in terms of algorithms. To the best of our knowledge, most existing approaches for high dimensional alignment are just simple extensions of their counterparts for 2D and 3D cases, and often suffer from the issues such as high complexities. In this paper, we propose an effective framework to compress the high dimensional geometric patterns and approximately preserve the alignment quality. As a consequence, existing alignment approach can be applied to the compressed geometric patterns and thus the time complexity is significantly reduced. Our idea is inspired by the observation that high dimensional data often has a low intrinsic dimension. We adopt the widely used notion "doubling dimension" to measure the extents of our compression and the resulting approximation. Finally, we test our method on both random and real datasets, the experimental results reveal that running the alignment algorithm on compressed patterns can achieve similar qualities, comparing with the results on the original patterns, but the running times (including the times cost for compression) are substantially lower

Unraveling Island Economies through Organic Residue Analysis: The Case of Mocha Island (Southern Chile)

Biophysical conditions played a fundamental role in early human colonization of insular territories, particularly in food-producing societies dealing with limited resources and the challenges of maintaining a sustainable carrying capacity. Studies on past human colonization of small oceanic islands thus offer insights into economic plasticity, ecological impacts, and adaptation of early food-producing groups. On the coast of southern Chile, early evidence is dated to 950 cal BP of island colonization by coastal populations with mainland subsistence systems based on the exploitation of marine resources, along with gathering, managing, and cultivating plants and hunting terrestrial animals. Strikingly, the extent to which these mixed economies contributed to insular colonization efforts is largely unknown. Here we used organic residue analysis of ceramic artifacts to shed light on the subsistence of populations on Mocha Island in southern Chile. We extracted and analyzed lipids from 51 pottery sherds associated with the El Vergel cultural complex that flourished in southern Chile between 950 and 400 cal BP. Chemical and stable isotope analysis of the extracts identified a range of food products, including C3 and C4 plants and marine organisms. The results reveal the central role of mixed subsistence systems in fueling the colonization of Mocha Island