| 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. |
- Günther, Torsten, et al.
(författare)
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Population genomics of Mesolithic Scandinavia : Investigating early postglacial migration routes and high-latitude adaptation
- 2018
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Ingår i: PLoS biology. - : Public Library of Science (PLoS). - 1544-9173 .- 1545-7885. ; 16:1
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Tidskriftsartikel (refereegranskat)abstract
- Scandinavia was one of the last geographic areas in Europe to become habitable for humans after the Last Glacial Maximum (LGM). However, the routes and genetic composition of these postglacial migrants remain unclear. We sequenced the genomes, up to 57x coverage, of seven hunter-gatherers excavated across Scandinavia and dated from 9,500-6,000 years before present (BP). Surprisingly, among the Scandinavian Mesolithic individuals, the genetic data display an east-west genetic gradient that opposes the pattern seen in other parts of Mesolithic Europe. Our results suggest two different early postglacial migrations into Scandinavia: initially from the south, and later, from the northeast. The latter followed the ice-free Norwegian north Atlantic coast, along which novel and advanced pressure-blade stone-tool techniques may have spread. These two groups met and mixed in Scandinavia, creating a genetically diverse population, which shows patterns of genetic adaptation to high latitude environments. These potential adaptations include high frequencies of low pigmentation variants and a gene region associated with physical performance, which shows strong continuity into modern-day northern Europeans.
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| 3. |
- Götherström, Anders, et al.
(författare)
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Bone preservation and DNA amplification
- 2002
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Ingår i: Archaeometry. - : Wiley. - 0003-813X .- 1475-4754. ; 44:3, s. 395-404
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Tidskriftsartikel (refereegranskat)abstract
- The use of ancient DNA has increased during the past two decades in several scientific disciplines. However, the underlying mechanism of DNA degradation in bone tissue are poorly understood. Here we address the importance of hydroxyapatite and collagen for DNA preservation in bone. We used two series of bones and teeth, one set of modern experimentally degraded bovid bones and one set of ancient horse bones/teeth. From these samples, we measured crystallinity, DNA presence and extracted collagen. The mtDNA fragments, parts of cytochrome b and the D-loop were amplified and sequenced. Our results show that presence of DNA was strongly related to the crystallinity in the hydroxyapatite and to the amount of collagen. This suggests that the hypothesis that hydroxyapatite has a crucial role in DNA preservation in calcified tissue is valid; and hydroxyapatite and collagen can be used to indicate whether DNA is present in the material. This is what would be expected if DNA is adsorbed to and stabilized by hydroxyapatite in calcified tissue, and collagen is part of the complex system that preserves DNA in bone tissue. Further, since collagen is the preferred material for radiocarbon dating, such bones may be a starting-point for a DNA analysis.
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| 4. |
- Hansson, Lars-Olof, et al.
(författare)
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Performance evaluation of a turbidimetric cystatin C assay on different high-throughput platforms
- 2010
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Ingår i: Scandinavian Journal of Clinical & Laboratory Investigation. - : Informa UK Limited. - 1502-7686 .- 0036-5513. ; 70:5, s. 347-353
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Tidskriftsartikel (refereegranskat)abstract
- Objective. The goal with this study was to evaluate the analytical performance of a new cystatin C immunoassay (Tina-quant (R) a Cystatin C, Roche Diagnostics GmbH). The evaluation was carried out at four centers according to a standardized protocol. Material and methods. The Tina-quant (R) a Cystatin C is a latex particle-enhanced immunoturbidimetric assay. Roche cobas (R) 6000, MODULAR ANALYTICS SWA and COBAS INTEGRA (R) instruments were included in the study. Method comparison studies were carried out against two turbidimetric methods (Dako Cystatin C, Gentian Cystatin C), and one nephelometric method (Siemens N-Latex Cystatin C). Results. Linearity was proven throughout the measuring range from 0.4 to 8 mg/L. Within-run CVs ranged from 0.7-2.8%, and total CVs from 1.4-4.7 % (concentration range 0.6-3.9 mg/L). Comparable results were obtained with paired serum and Li-heparinate plasma samples. Good agreement was achieved in the comparisons between the Tina-quant (R) a Cystatin C assay and the other commercially available cystatin C assays, two different turbidimetric methods (slope range 0.88-1.04, intercept < 0.17 mg/L, r >= 0.993) and one nephelometric assay (slope range 0.90-1.05, intercept < 0.21 mg/L, r >= 0.986). Conclusions. The Tina-quant (R) a Cystatin C assay was shown to be precise and accurate with proven linearity over the measuring range. Good comparability was obtained with other commercially available assays for the determination of cystatin C. The Tina-quant (R) a Cystatin C assay is very well suited for clinical use on routine clinical chemistry analysers to detect renal dysfunction with a 24 h availability.
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| 5. |
- Valdiosera, Cristina, et al.
(författare)
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Typing single polymorphic nucleotides in mitochondrial DNA as a way to access Middle Pleistocene DNA
- 2006
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Ingår i: Biology Letters. - : The Royal Society. - 1744-9561 .- 1744-957X. ; 2:4, s. 601-603
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we have used a technique designed to target short fragments containing informative mitochondrial substitutions to extend the temporal limits of DNA recovery and study the molecular phylogeny of Ursus deningeri. We present a cladistic analysis using DNA recovered from 400 kyr old U. deningeri remains, which demonstrates U. deningeri's relation to Ursus spelaeus. This study extends the limits of recovery from skeletal remains by almost 300 kyr. Plant material from permafrost environments has yielded DNA of this age in earlier studies, and our data suggest that DNA in teeth from cave environments may be equally well preserved.
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| 6. |
- Abdelaziz, Omar Y., et al.
(författare)
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Oxidative Depolymerization of Kraft Lignin for Microbial Conversion
- 2019
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Ingår i: ACS Sustainable Chemistry and Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 7:13, s. 11640-11652
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Tidskriftsartikel (refereegranskat)abstract
- The valorization of lignin is being increasingly recognized as crucial to improve the economic viability of integrated biorefineries. Because of its inherent heterogeneity and recalcitrance, lignin has been treated as a waste product in the pulp and paper industry, but new technologies are now being explored to transform lignin into a sustainable resource and enhance its value chain. In the present study, alkaline oxidative depolymerization was investigated as a potential form of pretreatment to enable further biological conversion of LignoBoost kraft lignin (LB). LB lignin oxidation reactions were studied at various temperatures (120-200 °C) and O2 partial pressures (3-15 bar) to identify the optimal conditions for obtaining a biocompatible, oxidatively depolymerized lignin (ODLB) stream. The low molecular weight compounds resulting from this treatment consisted mainly of aromatic monomers and carboxylic acids. The highest yield of aromatic monomers, 3 wt %, was obtained at 160 °C and 3 bar O2. The yield of carboxylic acids increased with both increasing temperature and O2 pressure, exceeding 13% under the harshest conditions investigated. The growth of four aromatic-catabolizing bacterial strains was examined on reaction product mixtures, all of which showed growth on agar plates utilizing ODLB as the sole source of carbon and energy. Rhodococcus opacus and Sphingobium sp. SYK-6 were found to consume most of the aromatic monomers present in the ODLB (e.g., vanillin, vanillate, acetovanillone, and guaiacol). The findings of this study indicate that pretreatment by oxidative depolymerization has potential in the biological valorization of technical lignin streams, for the production of valuable chemicals and materials.
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| 7. |
- Afzal, Zeeshan, 1991-, et al.
(författare)
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A Multipath TCP Proxy
- 2015
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Konferensbidrag (refereegranskat)abstract
- Multipath TCP (MPTCP) is an extension to traditionalTCP that enables a number of performance advantages,which were not offered before. While the protocol specificationis close to being finalized, there still remain some concernsregarding deployability and security. This paper describes theon going work to develop a solution that will facilitate thedeployment of MPTCP. The solution will not only allow non-MPTCP capable end-hosts to benefit from MPTCP performancegains, but also help ease the network security concerns that manymiddleboxes face due to the possibility of data stream beingfragmented across multiple subflows.
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| 8. |
- Afzal, Zeeshan, 1991-, et al.
(författare)
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Towards Multipath TCP Aware Security Technologies
- 2016
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Ingår i: 2016 8th IFIP International Conference onNew Technologies, Mobility and Security (NTMS). - New York : IEEE. - 9781509029143 ; , s. 1-8
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Konferensbidrag (refereegranskat)abstract
- Multipath TCP (MPTCP) is a proposed extension to TCP that enables a number of performance advantages that have not been offered before. While the protocol specification is close to being finalized, there still remain some unaddressed challenges regarding the deployment and security implications of the protocol. This work attempts to tackle some of these concerns by proposing and implementing MPTCP aware security services and deploying them inside a proof of concept MPTCP proxy. The aim is to enable hosts, even those without native MPTCP support, to securely benefit from the MPTCP performance advantages. Our evaluations show that the security services that are implemented enable proper intrusion detection and prevention to thwart potential attacks as well as threshold rules to prevent denial of service (DoS) attacks.
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| 9. |
- Ahlgren, Hans, et al.
(författare)
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Multiple prehistoric introductions of the mountain hare (Lepus timidus) on a remote island, as revealed by ancient DNA
- 2016
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Ingår i: Journal of Biogeography. - : Wiley. - 0305-0270 .- 1365-2699. ; 43:9, s. 1786-1796
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Tidskriftsartikel (refereegranskat)abstract
- Aim: The majority of the non-volant mammals now present on the island of Gotland, Sweden, have been introduced in modern times. One exception is the mountain hare (Lepus timidus), which was present on the island more than 9000 years ago. This paper investigates the origins of the Gotland hares and temporal changes in their genetic structure, and considers how they may have reached the island.Location: The island of Gotland, Sweden (57°30′ N, 18°20′ E).Methods: Two fragments of the mitochondrial D-loop 130 + 164 base pairs in length from skeletal remains from 40 ancient mountain hares from Gotland, 38 from the Swedish mainland and five from Lithuania were analysed and compared with 90 modern L. timidus haplotypes from different locations in Eurasia and five haplotypes of the Don-hare (Lepus tanaiticus) morphotype.Results: The Mesolithic hares from Gotland (7304 bc–5989 bc) cluster with modern hares from Russia, Scotland, the Alps and Fennoscandia whereas the Gotland hares from the Neolithic and onwards (2848 bc–1641 ad) cluster with Neolithic hares from the Swedish mainland and modern hares from Fennoscandia. The Neolithic haplotypes from Lithuania and the Don-hare haplotypes were dispersed within the network. The level of differentiation (FST) between the Mesolithic and Neolithic hares on Gotland was twice as great as that observed on the mainland.Main conclusions: The ancient hares on Gotland fall into two haplogroups separated in time, indicating that the mountain hare became extinct at one point, with subsequent re-colonization events. In view of the isolated location of Gotland, it is probable that the hares were brought there by human means of transport.
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| 10. |
- 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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