1. |
- Allentoft, Morten E., et al.
(författare)
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100 ancient genomes show repeated population turnovers in Neolithic Denmark
- 2024
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Ingår i: Nature. - 0028-0836 .- 1476-4687. ; 625, s. 329-337
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Tidskriftsartikel (refereegranskat)abstract
- Major migration events in Holocene Eurasia have been characterized genetically at broad regional scales1–4. However, insights into the population dynamics in the contact zones are hampered by a lack of ancient genomic data sampled at high spatiotemporal resolution5–7. Here, to address this, we analysed shotgun-sequenced genomes from 100 skeletons spanning 7,300 years of the Mesolithic period, Neolithic period and Early Bronze Age in Denmark and integrated these with proxies for diet (13C and 15N content), mobility (87Sr/86Sr ratio) and vegetation cover (pollen). We observe that Danish Mesolithic individuals of the Maglemose, Kongemose and Ertebølle cultures form a distinct genetic cluster related to other Western European hunter-gatherers. Despite shifts in material culture they displayed genetic homogeneity from around 10,500 to 5,900 calibrated years before present, when Neolithic farmers with Anatolian-derived ancestry arrived. Although the Neolithic transition was delayed by more than a millennium relative to Central Europe, it was very abrupt and resulted in a population turnover with limited genetic contribution from local hunter-gatherers. The succeeding Neolithic population, associated with the Funnel Beaker culture, persisted for only about 1,000 years before immigrants with eastern Steppe-derived ancestry arrived. This second and equally rapid population replacement gave rise to the Single Grave culture with an ancestry profile more similar to present-day Danes. In our multiproxy dataset, these major demographic events are manifested as parallel shifts in genotype, phenotype, diet and land use.
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2. |
- Allentoft, Morten E., et al.
(författare)
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Population genomics of post-glacial western Eurasia
- 2024
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Ingår i: Nature. - 0028-0836 .- 1476-4687. ; 625:7994, s. 301-311
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Tidskriftsartikel (refereegranskat)abstract
- Western Eurasia witnessed several large-scale human migrations during the Holocene1–5. Here, to investigate the cross-continental effects of these migrations, we shotgun-sequenced 317 genomes—mainly from the Mesolithic and Neolithic periods—from across northern and western Eurasia. These were imputed alongside published data to obtain diploid genotypes from more than 1,600 ancient humans. Our analyses revealed a ‘great divide’ genomic boundary extending from the Black Sea to the Baltic. Mesolithic hunter-gatherers were highly genetically differentiated east and west of this zone, and the effect of the neolithization was equally disparate. Large-scale ancestry shifts occurred in the west as farming was introduced, including near-total replacement of hunter-gatherers in many areas, whereas no substantial ancestry shifts happened east of the zone during the same period. Similarly, relatedness decreased in the west from the Neolithic transition onwards, whereas, east of the Urals, relatedness remained high until around 4,000 bp, consistent with the persistence of localized groups of hunter-gatherers. The boundary dissolved when Yamnaya-related ancestry spread across western Eurasia around 5,000 bp, resulting in a second major turnover that reached most parts of Europe within a 1,000-year span. The genetic origin and fate of the Yamnaya have remained elusive, but we show that hunter-gatherers from the Middle Don region contributed ancestry to them. Yamnaya groups later admixed with individuals associated with the Globular Amphora culture before expanding into Europe. Similar turnovers occurred in western Siberia, where we report new genomic data from a ‘Neolithic steppe’ cline spanning the Siberian forest steppe to Lake Baikal. These prehistoric migrations had profound and lasting effects on the genetic diversity of Eurasian populations.
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3. |
- Benesch, Henric, 1972, et al.
(författare)
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Ingreppsfestival
- 2010
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Ingår i: Kanaltorgsgatan, Heurlins plats, Stenpiren, Verkstadsgatan (Göteborg).
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- I samband med det forskningsprojektet Ingrepp genomfördes en Ingreppfestival med avseende på att i ett öppet publikt sammanhang diskutera utgångspunkterna forskningsgruppen formulerat i tabloiden Ingrepp – en tidning om städer, planering och konst, vilket delades ut gratis en vecka innan festivalen. I tidningen hittade man läsning kring städer, stadsutveckling, konst och konstnärlig forskning vilken hade bäring på den utvecklingsprocess som pågick och pågår på Södra Älvstranden i Göteborg. Både tabloiden och festivalen var ett direkt uttryck för gruppen vilja att ta ut diskussionen på gatan och i sitt sammanhang, men också ett sätt att pröva konstens och akademins möjligheter att gripa in och delta i samhälleliga skeenden. Festivalen vilken turnerade runt på fyra platser under fyra dagar längs Södra Älvstranden innefattade allt ifrån inbjudna samtal/debatter/seminarier till workshops kring Södra Älvstrandens framtid till tipspromenader, picnics och olika former av performativa iscensättningar under bar himmel.
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4. |
- Morrill, Johan, et al.
(författare)
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β-Mannanase-catalyzed synthesis of alkyl mannooligosides
- 2018
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Ingår i: Applied Microbiology and Biotechnology. - : Springer Science and Business Media LLC. - 0175-7598 .- 1432-0614. ; 102:12, s. 5149-5163
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Tidskriftsartikel (refereegranskat)abstract
- β-Mannanases catalyze the conversion and modification of β-mannans and may, in addition to hydrolysis, also be capable of transglycosylation which can result in enzymatic synthesis of novel glycoconjugates. Using alcohols as glycosyl acceptors (alcoholysis), β-mannanases can potentially be used to synthesize alkyl glycosides, biodegradable surfactants, from renewable β-mannans. In this paper, we investigate the synthesis of alkyl mannooligosides using glycoside hydrolase family 5 β-mannanases from the fungi Trichoderma reesei (TrMan5A and TrMan5A-R171K) and Aspergillus nidulans (AnMan5C). To evaluate β-mannanase alcoholysis capacity, a novel mass spectrometry-based method was developed that allows for relative comparison of the formation of alcoholysis products using different enzymes or reaction conditions. Differences in alcoholysis capacity and potential secondary hydrolysis of alkyl mannooligosides were observed when comparing alcoholysis catalyzed by the three β-mannanases using methanol or 1-hexanol as acceptor. Among the three β-mannanases studied, TrMan5A was the most efficient in producing hexyl mannooligosides with 1-hexanol as acceptor. Hexyl mannooligosides were synthesized using TrMan5A and purified using high-performance liquid chromatography. The data suggests a high selectivity of TrMan5A for 1-hexanol as acceptor over water. The synthesized hexyl mannooligosides were structurally characterized using nuclear magnetic resonance, with results in agreement with their predicted β-conformation. The surfactant properties of the synthesized hexyl mannooligosides were evaluated using tensiometry, showing that they have similar micelle-forming properties as commercially available hexyl glucosides. The present paper demonstrates the possibility of using β-mannanases for alkyl glycoside synthesis and increases the potential utilization of renewable β-mannans.
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5. |
- Rosengren, Anna, et al.
(författare)
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Enzymatic synthesis and polymerisation of β-mannosyl acrylates produced from renewable hemicellulosic glycans
- 2019
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Ingår i: Green Chemistry. - : Royal Society of Chemistry (RSC). - 1463-9270 .- 1463-9262. ; 21:8, s. 2104-2118
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Tidskriftsartikel (refereegranskat)abstract
- We show that glycoside hydrolases can catalyse the synthesis of glycosyl acrylate monomers using renewable hemicellulose as glycosyl donor, and we also demonstrate the preparation of novel glycopolymers by radical polymerisation of these monomers. For this, two family 5 β-mannanases (TrMan5A from Trichoderma reesei and AnMan5B from Aspergillus niger) were evaluated for transglycosylation capacity using 2-hydroxyethyl methacrylate (HEMA) as glycosyl acceptor. Both enzymes catalysed conjugation between manno-oligosaccharides and HEMA, as analysed with MALDI-ToF mass spectrometry (MS) as initial product screening method. The two enzymes gave different product profiles (glycosyl donor length) with HEMA, as well as with allyl alcohol as acceptor molecules. AnMan5A appeared to prefer saccharide acceptors with lower intensity MS peaks detected for the desired allyl and HEMA conjugations. Contrary to AnMan5A, TrMan5A gave pronounced MS peaks for HEMA-saccharide conjugation products.TrMan5A was shown to catalyse the synthesis of β-mannosyl acrylates using locust bean gum galactomannan or softwood hemicellulose (acetyl-galactoglucomannan) as donor substrate. Evaluation of reaction conditions using galactomannan as donor, HEMA as acceptor and TrMan5A as enzyme catalyst was followed by the enzymatic production and preparative liquid chromatography purification of 2-(β-manno(oligo)syloxy) ethyl methacrylates (Mannosyl-EMA and Mannobiosyl-EMA). The chemical structures and radical polymerisations of these novel monomers were concluded using 1H and 13C NMR spectroscopy and size-exclusion chromatography. The two new water soluble polymers have a polyacrylate backbone with one or two pendant mannosyl groups per monomeric EMA unit, respectively. These novel glycopolymers may show properties suitable for various technical and biomedical applications responding to the current demand for functional greener materials to replace fossil based ones.
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6. |
- Rosengren, Karl Erik
(författare)
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De Lege Delenda - International Legislation on Health-Related Genetics and Biotechnology
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Law should be the expression of the collective will, and the regulative sphere becomes therefore a highly consensual field supposed to reflect generally agreed norms and values. Although it is generally admitted that genetic and biotechnology developments can contribute to immense benefits within the health-care sector, the exponential globalisation trend and the rapid pace of scientific and technological developments in the field of modern biotechnology makes it however increasingly difficult to substantiate the ideal content of law. The modern life-world is surrounded nowadays by technical imperatives and is confronted by large numbers of reasonable requirements like those arising in the borderland between law and medicine or law and biology. The pace of development and the interplay pattern of unprecedented issues create challenges with which current institutions have considerable difficulties in coping. The dangerous consequence is a growing lack of a general view, the absence of a deeper understanding of the longer-term implications, which is so necessary for the sound development of any kind of balanced and fair global course of action. De Lege Delenda, the fading away of legislation, is meant to draw attention to the difficulties that classical regulation encounters in the face of both the complexity and the pace of recent technological developments, particularly in the field of biotechnology. Between the classical terms De Lege Lata, law as it is given, and De Lege Ferenda, law as it should be, as it should take form in the future, De Lege Delenda points not so much to the absence of efficient law in the field as to the impossibility of regulating these highly innovative fields with the classical tools of traditional law. It indicates a situation in which the regulatory institutions can neither provide a law capable through its implementation of guiding developments nor envisage any potential new way of reaching an ideal solution. The title reflects thus the conclusions drawn from a series of papers constituting this thesis and providing clear indications that legislation has lost much of its previous function and efficacy.
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