| 1. |
- 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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| 2. |
- 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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| 3. |
- Elberling, Bo, et al.
(författare)
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Soil and Plant Community Characteristics and Dynamics at Zackenberg
- 2008
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Ingår i: High-arctic ecosystem dynamics in a changing climate - Ten years of monitoring and research at Zackenberg Research Station, Northeast Greenland (Advances in Ecological Research). - 0065-2504. - 9780123736659 ; 40, s. 223-248
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Arctic soils hold large amounts of nutrients in the weatherable minerals and the soil organic matter, which slowly decompose. The decomposition processes release nutrients to the plant-available nutrient pool as well as greenhouse gases to the atmosphere. Changes in climatic conditions, for example, changes in the distribution of snow, water balance and the length of the growing season, are likely to affect the complex interactions between plants, abiotic and biotic soil processes as well as the composition of soil micro- and macro-fauna and thereby the overall decomposition rates. These interactions, in turn, will influence soil-plant functioning and vegetation composition in the short as well as in the long term. In this chapter, we report on soils and. plant communities and their distribution patterns in the valley Zackenbergdalen and focus on the detailed investigations within five dominating plant communities. These five communities are located along an ecological gradient in the landscape and are closely related to differences in water availability. They are therefore indirectly formed as a result of the distribution of landforms, redistribution of snow and drainage conditions. Each of the plant communities is closely related to specific nutrient levels and degree of soil development including soil element accumulation and translocation, for example, organic carbon. Results presented here show that different parts of the landscape have responded quite differently to the same overall climate changes the last 10 years and thus, most likely in the future too. Fens represent the wettest sites holding large reactive buried carbon stocks. A warmer climate will cause a permafrost degradation, which most likely will result in anoxic decomposition and increasing methane emissions. However, the net gas emissions at fen sites are sensitive to long-term changes in the water table level. Indeed, increasing maximum active layer depth at fen sites has been recorded together with a decreasing water level at Zackenberg. This is in line with the first signs of increasing extension of grasslands at the expense of fens. In contrast, the most exposed and dry areas have less soil carbon, and decomposition processes are periodically water limited. Here, an increase in air temperatures may increase active layer depth more than at fen sites, but water availability will be critical in determining nutrient cycling and plant production. Field manipulation experiments of increasing temperature, water supply and nutrient addition show that soil-plant interactions are sensitive to these variables. However, additional plant-specific investigations are needed before net effects of climate changes on different landscape and plant communities can be integrated in a landscape context and used to assess the net ecosystem effect of future climate scenarios.
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| 4. |
- Raghavan, Maanasa, et al.
(författare)
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The genetic prehistory of the New World Arctic
- 2014
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 345:6200, s. 1020-
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Tidskriftsartikel (refereegranskat)abstract
- The New World Arctic, the last region of the Americas to be populated by humans, has a relatively well-researched archaeology, but an understanding of its genetic history is lacking. We present genome-wide sequence data from ancient and present-day humans from Greenland, Arctic Canada, Alaska, Aleutian Islands, and Siberia. We show that Paleo-Eskimos (similar to 3000 BCE to 1300 CE) represent a migration pulse into the Americas independent of both Native American and Inuit expansions. Furthermore, the genetic continuity characterizing the Paleo-Eskimo period was interrupted by the arrival of a new population, representing the ancestors of present-day Inuit, with evidence of past gene flow between these lineages. Despite periodic abandonment of major Arctic regions, a single Paleo-Eskimo metapopulation likely survived in near-isolation for more than 4000 years, only to vanish around 700 years ago.
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| 5. |
- Ameen, Carly, et al.
(författare)
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Specialized sledge dogs accompanied Inuit dispersal across the North American Arctic
- 2019
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 286:1916
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Tidskriftsartikel (refereegranskat)abstract
- Domestic dogs have been central to life in the North American Arctic for millennia. The ancestors of the Inuit were the first to introduce the widespread usage of dog sledge transportation technology to the Americas, but whether the Inuit adopted local Palaeo-Inuit dogs or introduced a new dog population to the region remains unknown. To test these hypotheses, we generated mitochondrial DNA and geometric morphometric data of skull and dental elements from a total of 922 North American Arctic dogs and wolves spanning over 4500 years. Our analyses revealed that dogs from Inuit sites dating from 2000 BP possess morphological and genetic signatures that distinguish them from earlier Palaeo-Inuit dogs, and identified a novel mitochondrial clade in eastern Siberia and Alaska. The genetic legacy of these Inuit dogs survives today in modern Arctic sledge dogs despite phenotypic differences between archaeological and modern Arctic dogs. Together, our data reveal that Inuit dogs derive from a secondary pre-contact migration of dogs distinct from Palaeo-Inuit dogs, and probably aided the Inuit expansion across the North American Arctic beginning around 1000 BP.
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| 6. |
- Hansen, Bjarne H, et al.
(författare)
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The Scandinavian Sarcoma Group Skeletal Metastasis Registry Functional outcome and pain after surgery for bone metastases in the pelvis and extremities
- 2009
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Ingår i: ACTA ORTHOPAEDICA. - : Medical Journals Sweden AB. - 1745-3674 .- 1745-3682. ; 80, s. 85-90
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Tidskriftsartikel (refereegranskat)abstract
- Background Few authors have investigated function and pain after surgical treatment of patients with bone metastases. In 1999 the Scandinavian Sarcoma Group (SSG) initiated the Skeletal Metastasis Registry as a multi-centric, prospective study to provide a scientific basis for recommendations of treatment. Patients and methods We have analyzed function and pain in 530 patients (mean age 65 yr) operated on (599 operations) for non-spinal skeletal metastases at 9 SSG centres. 7% were operated for more than 1 metastasis. Carcinoma of the breast, prostate, kidney, and lung were the dominating sites for primary tumors. Results 25% of the patients died within 6 weeks after operation. 11% of the patients had complications. 6% had reoperation. In patients surviving more than 1 year the reoperation rate was 12%. 92% of the patients had no, light or moderate pain from metastasis at 6 weeks (first control) and 6 months follow-up. Patients using opioids were reduced from 40% preoperative to 30% at 6 months after surgery. In patients with metastases in pelvis or lower extremity 79% were walking with or without crutches, 6 weeks and 88%, 6 months after surgery. More patients with metastases; in proximal femur were mobile at 6 weeks and 6 months when treated with prosthetic replacement compared to internal fixation. Interpretation Palliative surgery for bone metastases improves function and reduce pain. Mobility is improved by surgery in patients with metastases in the pelvis or lower extremity. Prosthetic replacement seems to do better than internal fixation for metastases in the proximal femur. We need to analyze function and pain earlier than 6 weeks postoperative to investigate the benefit of surgery in patients with short time survival.
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| 7. |
- Rasmussen, Morten, et al.
(författare)
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Ancient human genome sequence of an extinct Palaeo-Eskimo
- 2010
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 463:7282, s. 757-762
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Tidskriftsartikel (refereegranskat)abstract
- We report here the genome sequence of an ancient human. Obtained from ∼4,000-year-old permafrost-preserved hair, the genome represents a male individual from the first known culture to settle in Greenland. Sequenced to an average depth of 20×, we recover 79% of the diploid genome, an amount close to the practical limit of current sequencing technologies. We identify 353,151 high-confidence single-nucleotide polymorphisms (SNPs), of which 6.8% have not been reported previously. We estimate raw read contamination to be no higher than 0.8%. We use functional SNP assessment to assign possible phenotypic characteristics of the individual that belonged to a culture whose location has yielded only trace human remains. We compare the high-confidence SNPs to those of contemporary populations to find the populations most closely related to the individual. This provides evidence for a migration from Siberia into the New World some 5,500 years ago, independent of that giving rise to the modern Native Americans and Inuit.
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| 8. |
- Ratasvuori, Maire, et al.
(författare)
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Prognostic role of en-bloc resection and late onset of bone metastasis in patients with bone-seeking carcinomas of the kidney, breast, lung, and prostate: SSG study on 672 operated skeletal metastases
- 2014
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Ingår i: Journal of Surgical Oncology. - : Wiley-Blackwell. - 0022-4790 .- 1096-9098. ; 110:4, s. 360-365
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Tidskriftsartikel (refereegranskat)abstract
- Background and Objectives In metastatic disease, decisions regarding potential surgery require reliable data about the patients survival. In this study, we evaluated different prognostic factors and their impact in four common primary tumors causing bone metastases. Methods Data were acquired from the Scandinavian Sarcoma Group (SSG) metastasis registry. The patients underwent surgery between July 1999 and July 2009. This study included breast, prostate, lung, and kidney cancer cases, with a total of 672 operated non-spinal metastases. Differences in prognostic factors were evaluated using the Kaplan-Meier method with long-rank test. Cox regression multivariate analysis was performed to identify statistically independent prognostic factors. Results Significant factors affecting survival were the presence of organ metastases, overall heath status, and disease load. In kidney cancer, en bloc resection of solitary metastases was associated with a significant fourfold longer survival compared to intralesional surgery. Preoperative radiotherapy was associated with higher complication and reoperation rates. Conclusions This data summary is important tool for clinicians to evaluate survival and choose treatment options for patients suffering from metastatic bone disease. J. Surg. Oncol. 2014; 110:360-365.
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| 9. |
- Wedin, Rikard, et al.
(författare)
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Complications and survival after surgical treatment of 214 metastatic lesions of the humerus
- 2012
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Ingår i: Journal of Shoulder and Elbow Surgery. - : Elsevier BV. - 1058-2746 .- 1532-6500. ; 21:8, s. 1049-1055
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Tidskriftsartikel (refereegranskat)abstract
- Background: The humerus is the second most common long-bone site of metastatic bone disease. We report complications, risk factors for failure, and survival of a large series of patients operated on for skeletal metastases of the humerus. Materials and methods: This study was based on 208 patients treated surgically for 214 metastatic lesions of the humerus. Reconstructions were achieved by intramedullary nails in 148, endoprostheses in 35, plate fixation in 21, and by other methods in 10. Results: The median age at surgery was 67 years (range, 29-87 years). Breast cancer was the primary tumor in 31%. The overall failure rate of the surgical reconstructions was 9%. The reoperation rate was 7% in the proximal humerus, 8% in the diaphysis, and 33% in the distal part of the bone. Among 36 operations involving an endoprosthesis, 2 were failures (6%) compared with 18 of 178 osteosynthetic devices (10%). In the osteosynthesis group, intramedullary nails failed in 7% and plate fixation failed in 22%. Multivariate Cox regression analysis showed that prostate cancer was associated with an increased risk of failure after surgery (hazard ratio, 7; P < 0.033). The cumulative survival after surgery was 40% (95% confidence interval [CI] 34-47) at 1 year, 21% (95% CI, 15-26) at 2 years, and 16% (95% CI, 12-19) at 3 years. Conclusions: Our method of choice is the cemented hemiprosthesis for pathologic proximal humeral fractures and interlocked intramedullary nail for lesions in the diaphysis. Pathologic fractures in the distal humerus are uncommon and associated with a very high reoperation rate. Level of evidence: Level IV, Case Series, Treatment Study. (C) 2012 Journal of Shoulder and Elbow Surgery Board of Trustees.
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