| 1. |
- Ahlgren, Hans, 1984-
(författare)
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Prehistoric human impact on wild mammalian populations in Scandinavia
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis aims to study the interactions of pre-agricultural societies in Scandinavia with wild mammals, for example in terms of hunting and translocation. More specifically, the aim is to investigate the possibility of identifying examples of overexploitation, targeted hunting or translocation of wild mammals in prehistoric Scandinavia, and to discuss the implications this could have had for both the wild animals and the humans. The thesis also studies translocation to evaluate the feasibility of using it as a proxy for prehistoric human mobility, and to understand the motivation for this action. Although the focus is on the animals in this thesis, the ultimate purpose is to study humans and their interactions with animals in prehistory. The thesis applies genetic analyses to zooarchaeological material of various mammalian species from different Scandinavian sites, in order to study whether the genetic structures have changed in these species over time, and to assess whether these changes were induced by different human actions. The species studied in this thesis were selected on the basis of the importance they are considered to have had for prehistoric people.The dissertation comprises five studies. The first study investigates the occurrence of mountain hares on the island of Gotland, and discusses how they got there and where they came from. The second study explores the temporal genetic structure of the grey seal in the Baltic Sea, and discusses whether humans and/or climate were the drivers for the sudden disappearance of grey seals from the island of Stora Karlsö. The third study concerns a shift where moose apparently became less important as prey in northern Sweden at the end of the Neolithic period, and discusses whether humans targeted female moose in hunting. The fourth study analyses and discusses the history of the harp seal in the Baltic Sea. The fifth study is a methodological paper which involves identifying seals according to sex, using the dog genome.The overall result of the different case studies shows that there were major population fluctuations over time in all the species studied, and that in some cases, humans are likely to have contributed to this, e.g. through overhunting and translocation. The study also shows that the population fluctuations often occurred in connection with certain climatic events, though it was not possible to separate climatic effects from human impact in terms of the cause.
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| 2. |
- Ahlgren, Hans, 1984-, et al.
(författare)
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The Baltic grey seal : A 9000-year history of presence and absence
- 2022
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Ingår i: The Holocene. - : SAGE Publications. - 0959-6836 .- 1477-0911. ; 32:6, s. 569-577
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Tidskriftsartikel (refereegranskat)abstract
- The grey seal (Halichoerus grypus) has been part of the Baltic Sea fauna for more than 9000 years and has ever since been subjected to extensive human hunting, particularly during the early phases of its presence in the Baltic Sea, but also in the early 20th century. In order to study their temporal genetic structure and to investigate whether there has been a genetically continuous grey seal population in the Baltic, we generated mitochondrial control region data from skeletal remains from ancient grey seals from the archaeological sites Stora Förvar (Sweden) and Neustadt (Germany) and compared these with modern grey seal data. We found that the majority of the Mesolithic grey seals represent haplotypes that is not found in contemporary grey seals, indicating that the Baltic Sea population went extinct, likely due to human overexploitation and environmental change. We hypothesize that grey seals recolonised the Baltic Sea from the North Sea. during the Bronze Age or Iron Age, and that the contemporary Baltic grey seal population is direct descendants of this recolonisation. Our study highlights the power of biomolecular archaeology to understand the factors that shape contemporary marine diversity.
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| 3. |
- Bergfeldt, Nora, et al.
(författare)
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Identification of microbial pathogens in Neolithic Scandinavian humans
- 2024
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Ingår i: Scientific Reports. - : NATURE PORTFOLIO. - 2045-2322. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- With the Neolithic transition, human lifestyle shifted from hunting and gathering to farming. This change altered subsistence patterns, cultural expression, and population structures as shown by the archaeological/zooarchaeological record, as well as by stable isotope and ancient DNA data. Here, we used metagenomic data to analyse if the transitions also impacted the microbiome composition in 25 Mesolithic and Neolithic hunter-gatherers and 13 Neolithic farmers from several Scandinavian Stone Age cultural contexts. Salmonella enterica, a bacterium that may have been the cause of death for the infected individuals, was found in two Neolithic samples from Battle Axe culture contexts. Several species of the bacterial genus Yersinia were found in Neolithic individuals from Funnel Beaker culture contexts as well as from later Neolithic context. Transmission of e.g. Y. enterocolitica may have been facilitated by the denser populations in agricultural contexts.
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| 4. |
- Bergfeldt, Nora, et al.
(författare)
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Identification of microbial pathogens in Neolithic Scandinavian humans
- 2024
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Ingår i: Scientific Reports. - : NATURE PORTFOLIO. - 2045-2322. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- With the Neolithic transition, human lifestyle shifted from hunting and gathering to farming. This change altered subsistence patterns, cultural expression, and population structures as shown by the archaeological/zooarchaeological record, as well as by stable isotope and ancient DNA data. Here, we used metagenomic data to analyse if the transitions also impacted the microbiome composition in 25 Mesolithic and Neolithic hunter-gatherers and 13 Neolithic farmers from several Scandinavian Stone Age cultural contexts. Salmonella enterica, a bacterium that may have been the cause of death for the infected individuals, was found in two Neolithic samples from Battle Axe culture contexts. Several species of the bacterial genus Yersinia were found in Neolithic individuals from Funnel Beaker culture contexts as well as from later Neolithic context. Transmission of e.g. Y. enterocolitica may have been facilitated by the denser populations in agricultural contexts.
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| 5. |
- Feuerborn, Tatiana Richtman, 1993-
(författare)
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Genomic insights into the population history of circumpolar Arctic dogs
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The Siberian and North American Arctic have both borne witness to numerous migrations of humans and with them their dogs. This PhD thesis is based on whole genome data from 22 Siberian dogs and 72 North American Arctic dogs, in addition to 186 mitochondrial genomes Siberian and North American Arctic dogs. Mitochondrial genome data allowed for the identification of migration events that introduced distinct dog populations to North America, associated with different cultural complexes arriving to the region. A novel mitochondrial clade was also identified in dogs from eastern Siberia and Alaska. Genetic analysis was performed to confirm the macroscopic identification of fur used to make clothing in the Arctic in conjunction with stable isotope analyses to explore dietary differences of dog populations across the circumpolar region. The whole genome data generated for this PhD also detected and explored evidence for several gene flow events from West Eurasian dogs into the dogs of Siberia starting 10,900 BP. There was an additional gene flow event that introduced Near East related ancestry to the dogs of the Siberian Steppe before the Late Bronze Age. Dogs carrying this West Eurasian ancestry spread throughout Siberia, reaching northwestern Siberia by the Iron Age, by 2,000 BP. Further gene flow was detected later in Siberia from West Eurasia a thousand years later. North American Arctic dogs universally carry the Near East related ancestry that is seen in Siberian dogs starting in the Bronze Age, showing it had reached the Bering Strait before the ancestors of the Inuit departed Siberia for Alaska. Once in North America Inuit dogs experienced several other gene flow events from pre-contact subarctic dogs, modern European dogs, and wolves. The population structure seen in North American Arctic dogs reflects geography and the subsequent isolation as well as population turnover events associated with catastrophic epidemics in the dog populations. Finally, a simple method was developed to evaluate and remove human contamination from ancient DNA datasets originating from faunal taxa. All together this thesis has compiled genomic information from 94 Arctic dogs to shed light upon the genetic history of these dogs from the early Holocene through to the present day. This dataset has been able to provide insight not only into past dynamics of Arctic dogs but also a much needed resource for understanding and preserving the indigenous dog populations still present in the Arctic that face continued challenges of globalisation and climate change.
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| 6. |
- Fjellström, Markus, 1987-, et al.
(författare)
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Approaching historic reindeer herding in Northern Sweden by stable isotope analysis
- 2020
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Ingår i: Journal of Nordic Archaeological Science. - 1650-1519. ; 19, s. 63-75
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Tidskriftsartikel (refereegranskat)abstract
- A strong cultural connection exists between reindeer and modern Sámi identityand economy. Reindeer domestication is, however, a rather late event, andthere are many Sámi who live off resources other than reindeer herding. Theuse of stable isotope analysis on historic reindeer from different geographicareas can contribute to analysing both the processes involved in reindeer domesticationand different environmental utilization by the Sámi. In this study,reindeer bones from six different sites in northern Sweden, ranging in datefrom the 11th to the 20th century, were analysed for stable isotopes to studyhow reindeer have been utilized in various historic contexts – settlements,offering sites and a marketplace. The stable isotope analysis demonstrateddifferent practices in utilization of reindeer, such as foddering. Foddering issuggested to have caused the elevated δ15N values found in reindeer at theoffering sites Vindelgransele and Unna Saiva, as well as at the settlementVivallen. The analysis further indicates that the offering sites were used bysingle Sámi groups. An important outcome of our study is that the biologyof reindeer in Sápmi was culturally influenced by the Sámi even before thereindeer was domesticated.
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| 7. |
- Harris, Alison J. T., 1982-, et al.
(författare)
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Archives of human-dog relationships : Genetic and stable isotope analysis of Arctic fur clothing
- 2020
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Ingår i: Journal of Anthropological Archaeology. - : Elsevier BV. - 0278-4165 .- 1090-2686. ; 59
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Tidskriftsartikel (refereegranskat)abstract
- Among Indigenous populations of the Arctic, domestic dogs (Canislupus familiaris) were social actors aiding in traction and subsistence activities. Less commonly, dogs fulfilled a fur-bearing role in both the North American and Siberian Arctic. Examples of garments featuring dog skins were collected during the 19th-20th centuries and are now curated by the National Museum of Denmark. We sequenced the mitochondrial genomes of macroscopically identified dog skin garments. We conducted stable carbon and nitrogen isotope ratio analysis of the dog furs and of fur samples from contemporaneous pelts of Arctic (C. lupus arctos) and grey (C. lupus) wolves. Despite the presence of biocides used to protect the fur clothing during storage, we extracted well-preserved DNA using a minimally-invasive sampling protocol. Unexpectedly, the mtDNA genomes of one-third of the samples were consistent with wild taxa, rather than domestic dogs. The strong marine component in the diets of North American dogs distinguished them from Greenland and Canadian wolves, but Siberian dogs consumed diets that were isotopically similar to wild species. We found that dog provisioning practices were variable across the Siberian and North American Arctic, but in all cases, involved considerable human labor.
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| 8. |
- Jendeberg, Johan, 1972-
(författare)
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Non-enhanced single-energy computed tomography of urinary stones
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Computed tomography (CT) is the mainstay imaging method for urinary stones.The aim of this thesis was to optimize the information obtained from the initial CT scan to allow a well-founded diagnosis and prognosis, and to guide the clinician as early and as far as possible in the further treatment of urinary stone disease.We examined CT scan parameters with regards to their importance for prediction of spontaneous ureteral stone passage, the impact of interreader variability of stone size estimates on this prediction, and the predictive accuracy of a semi-automated, three-dimensional (3D) segmentation algorithm. We also developed and tested the ability of a machine learning algorithm to classify pelvic calcifications into ureteral stones and phleboliths.Using single-energy CT, three quantitative methods for classification of stone composition into uric acid and non-uric acid stones in vivo were prospectively validated, using dual-energy CT as reference.Our results show that spontaneous ureteral stone passage can be predicted with high accuracy, with knowledge of stone size and position. The interreader variability in the size estimation has a large impact on the predicted outcome, but can be eliminated through a 3D segmentation algorithm. Which size estimate we use is of minor importance, but it is important that we use the chosen estimate consistently. A machine learning algorithm can differentiate distal ureteral stones from phleboliths, but more than local features are needed to reach optimal discrimination.A single-energy CT method can distinguish uric acid from non-uric acid stones in vivo with accuracy comparable to dual-energy CT.In conclusion, single-energy CT not only detects a urinary stone, but can also provide us with a prediction regarding spontaneous stone passage and a classification of stone type into uric acid and non-uric acid.
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| 9. |
- Rodríguez-Varela, Ricardo, et al.
(författare)
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The genetic history of Scandinavia from the Roman Iron Age to the present
- 2023
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Ingår i: Cell. - : Elsevier. - 0092-8674 .- 1097-4172. ; 186:1, s. 32-46
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Tidskriftsartikel (refereegranskat)abstract
- We investigate a 2,000-year genetic transect through Scandinavia spanning the Iron Age to the present, based on 48 new and 249 published ancient genomes and genotypes from 16,638 modern individuals. We find regional variation in the timing and magnitude of gene flow from three sources: the eastern Baltic, the British-Irish Isles, and southern Europe. British-Irish ancestry was widespread in Scandinavia from the Viking period, whereas eastern Baltic ancestry is more localized to Gotland and central Sweden. In some regions, a drop in current levels of external ancestry suggests that ancient immigrants contributed proportionately less to the modern Scandinavian gene pool than indicated by the ancestry of genomes from the Viking and Medieval periods. Finally, we show that a north-south genetic cline that characterizes modern Scandinavians is mainly due to the differential levels of Uralic ancestry and that this cline existed in the Viking Age and possibly earlier.
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| 10. |
- Sandstedt, Mårten, 1972-
(författare)
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Computed Tomography of the Coronary Arteries : Developmental and Prognostic Investigations
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Computed tomography (CT) is an increasingly used modality for investigations of patients with suspected coronary artery disease (CAD). Technical advances could improve diagnostic accuracy and lead to clinical workflow improvements. Also, more prognostic information can optimize clinical follow-up strategies and treatments.The general aim of this thesis was to explore the use of CT for CAD investigations. Three studies aimed to examine new technologies, including the evaluation of an on-site, computed tomography-based fractional flow reserve (CT-FFR) software (study I), the evaluation of an AI-based, calcium scoring computed tomography (CSCT) software (study III), and the evaluation of an photon-counting detector (PCD)-CT (study IV). One study aimed to evaluate the long-term prognostic value of coronary computed tomography angiography (CCTA) in symptomatic patients with no history of CAD (study II).The software evaluation studies (study I and III) and the prognostic study (study II) utilized CT data from clinical patients, while the PCD-CT evaluation study (study IV) used CT data from cadaveric specimens. The performances of both software programs were compared with standard references, being represented by fractional flow reserve (FFR) measurements (study I), and coronary artery calcification (CAC) scores from a semi-automatic software (study III), respectively. The PCD-CT performance on CAC quantification was compared with corresponding results from an energy integrating detector (EID)-CT, using micro-CT as the standard reference (study IV). The prognostic study merged registries to identify major adverse cardiac events (MACE), having a follow-up time of up to 7.5 years (study II).The CT-FFR and CSCT software correlation and agreement to corresponding standard references were good and excellent, respectively. Also, both software programs had time-saving potential (study I and III). The CAC quantification was more accurate using PCD-CT than EID-CT (study IV). The prognosis was excellent in patients with normal coronary arteries, and progressively impaired in non-obstructive and obstructive CAD (study II).The results in this thesis convey developmental, technical CT technology advances for CAD investigations. In addition, prognostic follow-up data is communicated. The results may benefit patients by an increased accuracy in the CT evaluation of CAD and can contribute to improve clinical follow-up strategies. Furthermore, the results suggest possibilities to improve the workflow in clinical radiology, which potentially could impact health care costs.
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