315 results on '"Göran Possnert"'
Search Results
2. An unknown source of reactor radionuclides in the Baltic Sea revealed by multi-isotope fingerprints
- Author
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Jixin Qiao, Haitao Zhang, Peter Steier, Karin Hain, Xiaolin Hou, Vesa-Pekka Vartti, Gideon M. Henderson, Mats Eriksson, Ala Aldahan, Göran Possnert, and Robin Golser
- Subjects
Science - Abstract
Anthropogenic activities lead to the accumulation of radioactive substances in the environment. Here the authors use multi-isotopic fingerprints of uranium and iodine to discover a previously unknown source of reactor uranium in the Baltic Sea, likely sourced from a Swedish nuclear facility.
- Published
- 2021
- Full Text
- View/download PDF
3. About Ancient Ceramic Traditions of the Population of the Northern Caspian Region
- Author
-
Aleksandr A. Vybornov, Irina N. Vasilyeva, Marianna A. Kulkova, Мarkku Oinonen, Göran Possnert, and Larisa A. Nesterova
- Subjects
northern caspian region ,neolithic ,radiocarbon dating ,historical and cultural approach ,technical and technological analysis of ceramics ,History of Russia. Soviet Union. Former Soviet Republics ,DK1-4735 ,International relations ,JZ2-6530 - Abstract
Introduction. The territory of the Northern Caspian region plays an important role in the study of the Neolithic of Eastern Europe. The main criterion of this period is clay pottery. One of the difficult issues is the time of the ceramic technology appearance. Methods and materials. The study of the pottery technology of the Neolithic population of the Northern Caspian region is carried out in the framework of the historical and cultural approach to the study of ceramics, according to the method of A. Bobrinsky. The technique is based on binocular microscopy, tracology and experiment in the form of physical modeling. The basis for identifying technological traces on ceramics is the comparative analysis of the vessels under study with the base of standards. It is made by means of physical modeling in field and laboratory conditions. The age of the Neolithic monuments was determined using traditional methods in radiocarbon laboratories in Russia and Ukraine, as well as using AMS at universities in Sweden and Finland. Analysis. Over the past 10 years, more than 68 radiocarbon dates on different materials such as charcoal, bones, organics from ceramics, charred crusts, humus have been obtained. They give the possibility to determine the time of appearance and spread of the earliest pottery in the Northern Caspian region. This is the middle 7th millennium BC. The chronological framework for the development of the Neolithic in the Northern Caspian region is ca. 6600–5500 BC. The paper establishes the main and specific features of ceramic traditions. Results.The technical and technological analysis allows to reveal the genesis, the features of dynamics and further development of pottery in this region. The complex of results obtained allows to attribute the Neolithic sites of the Caspian region to the earliest pottery areal in Eastern Europe.
- Published
- 2020
- Full Text
- View/download PDF
4. The Influence of Orbital Forcing on 10Be Deposition in Greenland Over the Glacial Period
- Author
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Anna Sturevik-Storm, Minjie Zheng, Ala Aldahan, Göran Possnert, and Raimund Muscheler
- Subjects
orbital forcing ,10Be ,atmospheric transport ,aerosol ,ice core ,Greenland ,Science - Abstract
Understanding the transport and deposition of the cosmogenic isotope 10Be is vital for the application of the isotope data to infer past changes of solar activity, to reconstruct past Earth’s magnetic field intensity and climate change. Here, we use data of the cosmogenic isotope 10Be from the Greenland ice cores, namely the NEEM and GRIP ice cores, to identify factors controlling its distribution. After removing the effects of the geomagnetic field on the cosmogenic radionuclide production rate, the results expose imprints of the 20–22 ka precession cycle on the Greenland 10Be records of the last glacial period. This finding can further improve the understanding of 10Be variability in ice sheets and has the prospect of providing better reconstructions of geomagnetic and solar activity based on cosmogenic radionuclide records.
- Published
- 2021
- Full Text
- View/download PDF
5. Meningioma growth dynamics assessed by radiocarbon retrospective birth dating
- Author
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Hagen B. Huttner, Olaf Bergmann, Mehran Salehpour, Raouf El Cheikh, Makoto Nakamura, Angelo Tortora, Paula Heinke, Roland Coras, Elisabet Englund, Ilker Y. Eyüpoglu, Joji B. Kuramatsu, Sebastian S. Roeder, Stephan P. Kloska, Iris Muehlen, Arnd Doerfler, Stefan Schwab, Göran Possnert, Samuel Bernard, and Jonas Frisén
- Subjects
Radiocarbon ,C14 ,Meningioma ,Tumor growth ,Medicine ,Medicine (General) ,R5-920 - Abstract
It is not known how long it takes from the initial neoplastic transformation of a cell to the detection of a tumor, which would be valuable for understanding tumor growth dynamics. Meningiomas show a broad histological, genetic and clinical spectrum, are usually benign and considered slowly growing. There is an intense debate regarding their age and growth pattern and when meningiomas should be resected. We have assessed the age and growth dynamics of 14 patients with meningiomas (WHO grade I: n = 6 with meningothelial and n = 6 with fibrous subtype, as well as n = 2 atypical WHO grade II meningiomas) by combining retrospective birth-dating of cells by analyzing incorporation of nuclear-bomb-test-derived 14C, analysis of cell proliferation, cell density, MRI imaging and mathematical modeling. We provide an integrated model of the growth dynamics of benign meningiomas. The mean age of WHO grade I meningiomas was 22.1 ± 6.5 years, whereas atypical WHO grade II meningiomas originated 1.5 ± 0.1 years prior to surgery (p
- Published
- 2018
- Full Text
- View/download PDF
6. Water Circulation and Marine Environment in the Antarctic Traced by Speciation of 129I and 127I
- Author
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Shan Xing, Xiaolin Hou, Ala Aldahan, Göran Possnert, Keliang Shi, Peng Yi, and Weijian Zhou
- Subjects
Medicine ,Science - Abstract
Abstract Emissions of anthropogenic 129I from human nuclear activities are now detected in the surface water of the Antarctic seas. Surface seawater samples from the Drake Passage, Bellingshausen, Amundsen, and Ross Seas were analyzed for total 129I and 127I, as well as for iodide and iodate of these two isotopes. The variability of 127I and 129I concentrations and their species (127I−/127IO3 −, 129I−/129IO3 −) suggest limited environmental impact where ((1.15–3.15) × 106 atoms/L for 129I concentration and (0.61–1.98) × 10−11 for 129I/127I atomic ratios are the lowest ones compared to the other oceans. The iodine distribution patterns provide useful information on surface water transport and mixing that are vital for better understanding of the Southern Oceans effects on the global climate change. The results indicate multiple spatial interactions between the Antarctic Circumpolar Current (ACC) and Antarctic Peninsula Coastal Current (APCC). These interactions happen in restricted circulation pathways that may partly relate to glacial melting and icebergs transport. Biological activity during the warm season should be one of the key factors controlling the reduction of iodate in the coastal water in the Antarctic.
- Published
- 2017
- Full Text
- View/download PDF
7. The Lifespan and Turnover of Microglia in the Human Brain
- Author
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Pedro Réu, Azadeh Khosravi, Samuel Bernard, Jeff E. Mold, Mehran Salehpour, Kanar Alkass, Shira Perl, John Tisdale, Göran Possnert, Henrik Druid, and Jonas Frisén
- Subjects
microglia ,human ,turnover ,proliferation ,renewal ,Biology (General) ,QH301-705.5 - Abstract
The hematopoietic system seeds the CNS with microglial progenitor cells during the fetal period, but the subsequent cell generation dynamics and maintenance of this population have been poorly understood. We report that microglia, unlike most other hematopoietic lineages, renew slowly at a median rate of 28% per year, and some microglia last for more than two decades. Furthermore, we find no evidence for the existence of a substantial population of quiescent long-lived cells, meaning that the microglia population in the human brain is sustained by continuous slow turnover throughout adult life.
- Published
- 2017
- Full Text
- View/download PDF
8. Impact of fat mass and distribution on lipid turnover in human adipose tissue
- Author
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Kirsty L. Spalding, Samuel Bernard, Erik Näslund, Mehran Salehpour, Göran Possnert, Lena Appelsved, Keng-Yeh Fu, Kanar Alkass, Henrik Druid, Anders Thorell, Mikael Rydén, and Peter Arner
- Subjects
Science - Abstract
Lipid turnover in tissues can be calculated from ratios of different carbon isotopes. Here the authors use this approach to study lipid turnover in two distinct adipose tissue depots and find that, in obese individuals, visceral fat is more lipolytic than subcutaneous fat.
- Published
- 2017
- Full Text
- View/download PDF
9. Cell generation dynamics underlying naive T-cell homeostasis in adult humans.
- Author
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Jeff E Mold, Pedro Réu, Axel Olin, Samuel Bernard, Jakob Michaëlsson, Sanket Rane, Andrew Yates, Azadeh Khosravi, Mehran Salehpour, Göran Possnert, Petter Brodin, and Jonas Frisén
- Subjects
Biology (General) ,QH301-705.5 - Abstract
Thymic involution and proliferation of naive T cells both contribute to shaping the naive T-cell repertoire as humans age, but a clear understanding of the roles of each throughout a human life span has been difficult to determine. By measuring nuclear bomb test-derived 14C in genomic DNA, we determined the turnover rates of CD4+ and CD8+ naive T-cell populations and defined their dynamics in healthy individuals ranging from 20 to 65 years of age. We demonstrate that naive T-cell generation decreases with age because of a combination of declining peripheral division and thymic production during adulthood. Concomitant decline in T-cell loss compensates for decreased generation rates. We investigated putative mechanisms underlying age-related changes in homeostatic regulation of CD4+ naive T-cell turnover, using mass cytometry to profile candidate signaling pathways involved in T-cell activation and proliferation relative to CD31 expression, a marker of thymic proximity for the CD4+ naive T-cell population. We show that basal nuclear factor κB (NF-κB) phosphorylation positively correlated with CD31 expression and thus is decreased in peripherally expanded naive T-cell clones. Functionally, we found that NF-κB signaling was essential for naive T-cell proliferation to the homeostatic growth factor interleukin (IL)-7, and reduced NF-κB phosphorylation in CD4+CD31- naive T cells is linked to reduced homeostatic proliferation potential. Our results reveal an age-related decline in naive T-cell turnover as a putative regulator of naive T-cell diversity and identify a molecular pathway that restricts proliferation of peripherally expanded naive T-cell clones that accumulate with age.
- Published
- 2019
- Full Text
- View/download PDF
10. Carotid plaque age is a feature of plaque stability inversely related to levels of plasma insulin.
- Author
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Sara Hägg, Mehran Salehpour, Peri Noori, Jesper Lundström, Göran Possnert, Rabbe Takolander, Peter Konrad, Stefan Rosfors, Arno Ruusalepp, Josefin Skogsberg, Jesper Tegnér, and Johan Björkegren
- Subjects
Medicine ,Science - Abstract
BACKGROUND: The stability of atherosclerotic plaques determines the risk for rupture, which may lead to thrombus formation and potentially severe clinical complications such as myocardial infarction and stroke. Although the rate of plaque formation may be important for plaque stability, this process is not well understood. We took advantage of the atmospheric (14)C-declination curve (a result of the atomic bomb tests in the 1950s and 1960s) to determine the average biological age of carotid plaques. METHODOLOGY/PRINCIPAL FINDING: The cores of carotid plaques were dissected from 29 well-characterized, symptomatic patients with carotid stenosis and analyzed for (14)C content by accelerator mass spectrometry. The average plaque age (i.e. formation time) was 9.6±3.3 years. All but two plaques had formed within 5-15 years before surgery. Plaque age was not associated with the chronological ages of the patients but was inversely related to plasma insulin levels (p = 0.0014). Most plaques were echo-lucent rather than echo-rich (2.24±0.97, range 1-5). However, plaques in the lowest tercile of plaque age (most recently formed) were characterized by further instability with a higher content of lipids and macrophages (67.8±12.4 vs. 50.4±6.2, p = 0.00005; 57.6±26.1 vs. 39.8±25.7, p
- Published
- 2011
- Full Text
- View/download PDF
11. Analysis of the putative remains of a European patron saint--St. Birgitta.
- Author
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Martina Nilsson, Göran Possnert, Hanna Edlund, Bruce Budowle, Anna Kjellström, and Marie Allen
- Subjects
Medicine ,Science - Abstract
Saint Birgitta (Saint Bridget of Sweden) lived between 1303 and 1373 and was designated one of Europe's six patron saints by the Pope in 1999. According to legend, the skulls of St. Birgitta and her daughter Katarina are maintained in a relic shrine in Vadstena abbey, mid Sweden. The origin of the two skulls was assessed first by analysis of mitochondrial DNA (mtDNA) to confirm a maternal relationship. The results of this analysis displayed several differences between the two individuals, thus supporting an interpretation of the two skulls not being individuals that are maternally related. Because the efficiency of PCR amplification and quantity of DNA suggested a different amount of degradation and possibly a very different age for each of the skulls, an orthogonal procedure, radiocarbon dating, was performed. The radiocarbon dating results suggest an age difference of at least 200 years and neither of the dating results coincides with the period St. Birgitta or her daughter Katarina lived. The relic, thought to originate from St. Birgitta, has an age corresponding to the 13(th) century (1215-1270 cal AD, 2sigma confidence), which is older than expected. Thus, the two different analyses are consistent in questioning the authenticity of either of the human skulls maintained in the Vadstena relic shrine being that of St. Birgitta. Of course there are limitations when interpreting the data of any ancient biological materials and these must be considered for a final decision on the authenticity of the remains.
- Published
- 2010
- Full Text
- View/download PDF
12. No evidence of Neandertal mtDNA contribution to early modern humans.
- Author
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David Serre, André Langaney, Mario Chech, Maria Teschler-Nicola, Maja Paunovic, Philippe Mennecier, Michael Hofreiter, Göran Possnert, and Svante Pääbo
- Subjects
Biology (General) ,QH301-705.5 - Abstract
The retrieval of mitochondrial DNA (mtDNA) sequences from four Neandertal fossils from Germany, Russia, and Croatia has demonstrated that these individuals carried closely related mtDNAs that are not found among current humans. However, these results do not definitively resolve the question of a possible Neandertal contribution to the gene pool of modern humans since such a contribution might have been erased by genetic drift or by the continuous influx of modern human DNA into the Neandertal gene pool. A further concern is that if some Neandertals carried mtDNA sequences similar to contemporaneous humans, such sequences may be erroneously regarded as modern contaminations when retrieved from fossils. Here we address these issues by the analysis of 24 Neandertal and 40 early modern human remains. The biomolecular preservation of four Neandertals and of five early modern humans was good enough to suggest the preservation of DNA. All four Neandertals yielded mtDNA sequences similar to those previously determined from Neandertal individuals, whereas none of the five early modern humans contained such mtDNA sequences. In combination with current mtDNA data, this excludes any large genetic contribution by Neandertals to early modern humans, but does not rule out the possibility of a smaller contribution.
- Published
- 2004
- Full Text
- View/download PDF
13. The First Seal Hunter Families on Gotland - On the Mesolithic Occupation in the Stora Förvar Cave
- Author
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Christian Lindqvist and Göran Possnert
- Subjects
Archaeology ,CC1-960 - Abstract
The article presents some results of a joint interdisciplinary researchproject, The Stora Förvar Cave and Gotlands peopling, faunal history and subsistence economy/diet development from the Boreal to the Subatlantic, initiated by Christian Lindqvist in 1991. Its objectives include investigations of a number of crucial issues in a long-term perspective, such as the initial settlement, the early faunal history, the early subsistence economy and diet, but also the character of the Mesolithic-Neolithic shift on Gotland, by means of human and zooosteological, carbon isotope and ancient DNA analyses. The article presents and discusses artefact, osteological, and 13C and 14C data and interpretations concerning the duration and character of the Mesolithic occupation —temporary kill/butchering site, seasonal hunting station, semi-sedentary base camp or burial cave —as well as osteobiographical data on the identified human individuals and their burial customs.
- Published
- 1999
- Full Text
- View/download PDF
14. Anthropogenic 129I in seawaters along the north-central part of the English Channel: Levels and tracer applications
- Author
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Peng He, Zheng Yang, Hongying Pang, Ala Aldahan, Xiaolin Hou, Göran Possnert, Xiangjun Pei, and Yi Huang
- Subjects
Aquatic Science ,Oceanography - Published
- 2022
15. 66. Lake Vapsko-2, Rila Mountains (Bulgaria)
- Author
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Spassimir Tonkov, Göran Possnert, and Elena Marinova
- Subjects
Plant Science ,Ecology, Evolution, Behavior and Systematics - Published
- 2022
16. The First Seal Hunter Families on Gotland - On the Mesolithic Occupation in the Stora Förvar Cave
- Author
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Göran Possnert and Christian Lindqvist
- Subjects
Archeology ,geography ,geography.geographical_feature_category ,Cave ,Computer science ,Archaeology ,Mesolithic ,Seal hunter - Abstract
The article presents some results of a joint interdisciplinary researchproject, The Stora Förvar Cave and Gotlands peopling, faunal history and subsistence economy/diet development from the Boreal to the Subatlantic, initiated by Christian Lindqvist in 1991. Its objectives include investigations of a number of crucial issues in a long-term perspective, such as the initial settlement, the early faunal history, the early subsistence economy and diet, but also the character of the Mesolithic-Neolithic shift on Gotland, by means of human and zooosteological, carbon isotope and ancient DNA analyses. The article presents and discusses artefact, osteological, and 13C and 14C data and interpretations concerning the duration and character of the Mesolithic occupation —temporary kill/butchering site, seasonal hunting station, semi-sedentary base camp or burial cave —as well as osteobiographical data on the identified human individuals and their burial customs.
- Published
- 2021
17. PROFESSOR INGRID ULRIKA OLSSON (1927–2018): IN MEMORIAM
- Author
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Göran Possnert and Farid El-Daoushy
- Subjects
Archeology ,General Earth and Planetary Sciences - Published
- 2021
18. About Ancient Ceramic Traditions of the Population of the Northern Caspian Region
- Author
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Markku Oinonen, Larisa A. Nesterova, Göran Possnert, Irina N. Vasilyeva, Marianna Kulkova, Aleksandr Vybornov, Doctoral Programme in Geosciences, Unit of Biodiversity Informatics, and Natural Sciences Unit
- Subjects
Cultural Studies ,010506 paleontology ,History ,Sociology and Political Science ,Population ,01 natural sciences ,615 History and Archaeology ,law.invention ,law ,Northern Caspian region ,historical and cultural approach ,lcsh:DK1-4735 ,0601 history and archaeology ,Radiocarbon dating ,Neolithic ,education ,Arkeologi ,0105 earth and related environmental sciences ,education.field_of_study ,lcsh:History of Russia. Soviet Union. Former Soviet Republics ,060102 archaeology ,radiocarbon dating ,lcsh:International relations ,06 humanities and the arts ,Archaeology ,technical and technological analysis of ceramics ,Geography ,neolithic ,Political Science and International Relations ,Period (geology) ,northern caspian region ,Pottery ,lcsh:JZ2-6530 - Abstract
Introduction. The territory of the Northern Caspian region plays an important role in the study of the Neolithic of Eastern Europe. The main criterion of this period is clay pottery. One of the difficult issues is the time of the ceramic technology appearance. Methods and materials. The study of the pottery technology of the Neolithic population of the Northern Caspian region is carried out in the framework of the historical and cultural approach to the study of ceramics, according to the method of A. Bobrinsky. The technique is based on binocular microscopy, tracology and experiment in the form of physical modeling. The basis for identifying technological traces on ceramics is the comparative analysis of the vessels under study with the base of standards. It is made by means of physical modeling in field and laboratory conditions. The age of the Neolithic monuments was determined using traditional methods in radiocarbon laboratories in Russia and Ukraine, as well as using AMS at universities in Sweden and Finland. Analysis. Over the past 10 years, more than 68 radiocarbon dates on different materials such as charcoal, bones, organics from ceramics, charred crusts, humus have been obtained. They give the possibility to determine the time of appearance and spread of the earliest pottery in the Northern Caspian region. This is the middle 7th millennium BC. The chronological framework for the development of the Neolithic in the Northern Caspian region is ca. 6600–5500 BC. The paper establishes the main and specific features of ceramic traditions. Results.The technical and technological analysis allows to reveal the genesis, the features of dynamics and further development of pottery in this region. The complex of results obtained allows to attribute the Neolithic sites of the Caspian region to the earliest pottery areal in Eastern Europe.
- Published
- 2020
19. The Influence of Orbital Forcing on 10Be Deposition in Greenland Over the Glacial Period
- Author
-
Raimund Muscheler, Ala Aldahan, Anna Sturevik-Storm, Göran Possnert, and Minjie Zheng
- Subjects
Climate Research ,Orbital forcing ,aerosol ,atmospheric transport ,Science ,Greenland ,Climate change ,Klimatforskning ,glacial period ,Ice core ,Glacial period ,Be-10 ,Radionuclide ,geography ,geography.geographical_feature_category ,10Be ,orbital forcing ,Geology ,Earth's magnetic field ,General Earth and Planetary Sciences ,Geologi ,Physical geography ,Ice sheet ,Deposition (chemistry) ,ice core - Abstract
Understanding the transport and deposition of the cosmogenic isotope 10Be is vital for the application of the isotope data to infer past changes of solar activity, to reconstruct past Earth’s magnetic field intensity and climate change. Here, we use data of the cosmogenic isotope 10Be from the Greenland ice cores, namely the NEEM and GRIP ice cores, to identify factors controlling its distribution. After removing the effects of the geomagnetic field on the cosmogenic radionuclide production rate, the results expose imprints of the 20–22 ka precession cycle on the Greenland 10Be records of the last glacial period. This finding can further improve the understanding of 10Be variability in ice sheets and has the prospect of providing better reconstructions of geomagnetic and solar activity based on cosmogenic radionuclide records.
- Published
- 2021
20. 127I and 129I species in the English Channel and its adjacent areas: Uncovering impact on the isotopes marine pathways
- Author
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Peng He, Hongying Pang, Zheng Yang, Sihong Li, Yi Huang, Xiaolin Hou, Göran Possnert, Xuefeng Zheng, Xiangjun Pei, and Ala Aldahan
- Subjects
Environmental Engineering ,Ecological Modeling ,Pollution ,Waste Management and Disposal ,Water Science and Technology ,Civil and Structural Engineering - Published
- 2022
21. 46.Lake Panichishte, Rila Mountains (Bulgaria)
- Author
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Elissaveta Bozilova, Spassimir Tonkov, and Göran Possnert
- Subjects
Plant Science ,Ecology, Evolution, Behavior and Systematics - Published
- 2020
22. Late Holocene pathway of Asian Summer Monsoons imprinted in soils and societal implications
- Author
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Frank W. Schwartz, Li Chen, Weijian Zhou, Ahmed Murad, Peng Chen, Ala Aldahan, Edward A. Sudicky, Xiaolin Hou, Raimund Muscheler, Göran Possnert, Zhongbo Yu, Peng Yi, and Yukun Fan
- Subjects
010506 paleontology ,Archeology ,Global and Planetary Change ,geography ,Topsoil ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Bedrock ,Earth science ,Geology ,Weathering ,Monsoon ,01 natural sciences ,Spatial ecology ,East Asia ,Precipitation ,Ecology, Evolution, Behavior and Systematics ,Holocene ,0105 earth and related environmental sciences - Abstract
The Asian Summer Monsoons (ASM) represent the main source of precipitation in China and East Asia with about one third of the world population and a region of widespread civilizations. Identifying the temporal and spatial patterns (pathways) of these monsoonal events during the Late Holocene to today has been a matter of debate amongst the scientific community. Here we show that the distribution patterns of the cosmogenic isotope 10 Be and oceanic 127 I in the topsoil across China exhibit imprints of the main ASM pathways. Our results indicate the monsoon pathway pattern persisted for several millennia or more and suggest a strong bond between 10 Be and water vapor transport patterns. Our data also reveal a 127 I distribution pattern controlled by the ASM pathways, rather than proximity to the sea or bedrock weathering. The persistent pathway of the ASM during the late Holocene, together with higher than average global soil iodine concentration, may have further strengthened the development of civilizations in this region of the world through reduction of iodine deficiency related diseases.
- Published
- 2019
23. Use of 10Be isotope to predict landscape development in the source area of the Yellow River (SAYR), northeastern Qinghai-Tibet Plateau
- Author
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Ling Xiong, Zhongbo Yu, Mousong Wu, Chengwei Wan, Peng Yi, Dongliang Luo, Huijun Jin, Ala Aldahan, Minjie Zheng, Göran Possnert, Peng Chen, and Raimund Muscheler
- Subjects
Hydrology ,geography ,Plateau ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Soil and Water Assessment Tool ,Landform ,Health, Toxicology and Mutagenesis ,Sediment ,General Medicine ,010501 environmental sciences ,Structural basin ,Permafrost ,01 natural sciences ,Pollution ,Erosion ,Environmental Chemistry ,Environmental science ,Ecosystem ,Waste Management and Disposal ,0105 earth and related environmental sciences - Abstract
The magnitude of soil and sediment erosion and accumulation processes can profoundly affect landscape development and hamper efficient management of natural resources. Consequently, estimating the rates and causes of these processes is essential, particularly in remote regions, for prediction of changes in landform and river evolution and protection of local ecosystem. We here present the results of a soil and sediment erosion investigation in the Source Area of the Yellow River (SAYR), northeast Qinghai-Tibet Plateau based on a combined analysis of 10Be cosmogenic isotope and Soil and Water Assessment Tool (SWAT) simulation modelling. The data reveal variable soil erosion trends that range between 103 and 830 t km−2 a−1. The low values occur in the western part of the basin that are associated with low sediment yield, while the high values appear in the dominant sediment export part of the basin along the main stream of the Yellow River in the east. Generally, soil and sediment accumulation is characterized by high 10Be concentration in the western part and the northwest of Ngoring Lake. The style of landform development by the erosion/accumulation processes is closely linked to the distribution and degradation extent of the permafrost in the study region. Soil surface erosion increases with more permafrost degradation from the western to the eastern part of the basin, and surface soil particles are dominantly removed from the surface rather than deeper layers.
- Published
- 2019
24. Diploid hepatocytes drive physiological liver renewal in adult humans
- Author
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Paula Heinke, Fabian Rost, Julian Rode, Palina Trus, Irina Simonova, Enikő Lázár, Joshua Feddema, Thilo Welsch, Kanar Alkass, Mehran Salehpour, Andrea Zimmermann, Daniel Seehofer, Göran Possnert, Georg Damm, Henrik Druid, Lutz Brusch, and Olaf Bergmann
- Subjects
Adult ,Polyploidy ,Histology ,Liver ,Child, Preschool ,Cell- och molekylärbiologi ,Hepatocytes ,Humans ,Cell Biology ,Diploidy ,Cell and Molecular Biology ,Retrospective Studies ,Pathology and Forensic Medicine - Abstract
Physiological liver cell replacement is central to maintaining the organ's high metabolic activity, although its characteristics are difficult to study in humans. Using retrospective radiocarbon (C-14) birth dating of cells, we report that human hepatocytes show continuous and lifelong turnover, allowing the liver to remain a young organ (average age
- Published
- 2022
25. The results of the settlement Oroshayemoye study in 2018
- Author
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Natalya Valerievna Roslyakova, Marianna Alekseevna Kulkova, Mikhail Alexandrovich Streltsov, Alexander Alekseevich Vybornov, Göran Possnert, Alexander Sergeevich Popov, Alexander Ivanovich Yudin, Markku Oinonen, N. S. Doga, Pavel A. Kosintsev, and Irina N. Vasilyeva
- Subjects
biology ,Osteology ,Excavation ,Aurochs ,biology.organism_classification ,Archaeology ,law.invention ,Geography ,Tarpan ,law ,Period (geology) ,Radiocarbon dating ,Pottery ,Stratigraphy (archaeology) - Abstract
An essential aspect of studying the Neolithic is the identification of its early phase. The research is constrained by scarce source base of the study. Until recently, the early Neolithic in the Lower Volga region has not been identified by the experts. The situation has changed due to the excavation of the settlement Oroshayemoye I on the river B. Uzen. This paper focuses on the received materials. The monument is multi-layered. During the field work in 2018, the lower cultural layer was investigated. Ceramic, stone and osteological equipment was found in it. The pottery and set of tools are typologically similar to the materials of the lower layer of the Varfolomeyevskaya site, which belong to the Orlovskaya culture. The technological analysis of the ceramics of the Oroshayemoye settlement showed its proximity to the pottery making technology of Orlovskaya culture. The study of osteological remains revealed the presence of bones of aurochs, saiga, tarpan and other wild species on the monument, as well as a domestic dog. According to radiocarbon analysis, the age of the lower layer of the monument is determined by the last quarter of VII the beginning of the VI millennium BC. Paleoclimatic studies conducted on the monument showed that during this period the climate was warm and humid.
- Published
- 2018
26. Detection of an unknown emission source in the Baltic Sea using the new oceanographic tracer U-233/U-236
- Author
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Robin Golser, Mats Eriksson, Vesa-Pekka Vartti, Haitao Zhang, Göran Possnert, Ala Aldahan, Jixin Qiao, Xiaolin Hou, Peter Steier, Gideon M. Henderson, and Karin Hain
- Subjects
Oceanography ,Baltic sea ,TRACER ,Environmental science - Abstract
By analysing the two long-lived anthropogenic Uranium (U) isotopes U-233 and U-236 in different compartments of the environment affected by releases of nuclear power production or by global fallout from nuclear weapons tests, we showed that the corresponding isotopic ratios U-233/U-236 differ by one order of magnitude. Based on these experimental results which were obtained with the ultra-sensitive detection method Accelerator Mass Spectrometry, we suggested a representative ratio for nuclear weapons fallout of U-233/U-236 = (1.40 ± 0.15) ·10-2 and (0.12 ± 0.01) ·10-2 for releases from nuclear power production. Consequently, the U-233/U-236 ratio not only has the potential to become a novel sensitive fingerprint for releases from nuclear industry, but could also serve as a powerful oceanographic tracer due to the conservative behaviour of U in ocean water which does not suffer from chemical fractionation. As a first application of this paired tracer, we studied the distribution of U-233 and U-236 concentrations in addition to I-129 in the Baltic Sea which is known to have received inputs of radionuclides from various contamination sources including the two European reprocessing plants, global fallout from weapons testings and fallout from the Chernobyl accident. Our data indicate an additional unidentified source of reactor U-236 in the Baltic Sea demonstrating the high sensitivity of the U-233/U-236 ratio to distinguish different emission sources in water mixing processes.
- Published
- 2021
27. The dynamics of Holocene monsoon based on meteoric 10Be at Kunlun Pass on the northeastern Qinghai-Tibet Plateau
- Author
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Minjie Zheng, Jinguo Wang, Peng Yi, Göran Possnert, Peng Chen, Zhongbo Yu, Dongliang Luo, Markus Czymzik, Huijun Jin, Ala Aldahan, Qingbai Wu, and Xuegao Chen
- Subjects
Qinghai tibet plateau ,Physical geography ,Monsoon ,Holocene ,Geology - Abstract
Multiple proxy records have been used for the understanding of environmental and climate changes during the Holocene. For the first time, we here measure meteoric 10Be isotope of sediments from a drill core collected at the Kunlun Pass (KP) on the northeastern Qinghai-Tibet Plateau (NETP) to investigate mositure and atmospheric circulation changes during the Holocene. The 10Be flux suggests relative low levels in the Early Holocene, followed by a sharp increase to high values at around 4 ka BP (4 ka BP = 4000 years before present). Afterwards, the 10Be flux remains on a high level during the Late Holocene, but decreases slightly towards today. These 10Be deposition patterns are compared to moisture changes in regions dominated by the Indian Summer Monsoon (ISM), East Asian Summer Monsoon (EASM), and the Westerlies. Different from the gradual changes in monsoon patterns, the 10Be data reveal low levels during the Early Holocene until ~4 ka BP when an obvious increase was indicated and a relative high level continues to this day, which is relatively more in agreement with patterns of the Westerlies. This finding provides a new evidence for a shift in the dominant pattern of atmospheric circulation at the KP region from a more monsoonal one to one dominated by the Westerlies. Our results improve the understanding of non-stationary interactions and spatial relevance of the EASM, the ISM and the Westerlies on the Qinghai-Tibet Plateau.
- Published
- 2021
28. Solar Activity of the Past 100 Years Inferred From10Be in Ice Cores—Implications for Long‐Term Solar Activity Reconstructions
- Author
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Florian Adolphi, Mousong Wu, Jesper Sjolte, Göran Possnert, Ala Aldahan, Peng Chen, Raimund Muscheler, and Minjie Zheng
- Subjects
Climate Research ,010504 meteorology & atmospheric sciences ,solar reconstructions ,seasonally resolved Be-10 ,010502 geochemistry & geophysics ,Multidisciplinär geovetenskap ,01 natural sciences ,Klimatforskning ,Term (time) ,neutron monitor data ,Geophysics ,Ice core ,13. Climate action ,Climatology ,General Earth and Planetary Sciences ,Geosciences, Multidisciplinary ,ice core ,Dye3 ,NEEM ,Geology ,0105 earth and related environmental sciences - Abstract
Differences between 10Be records from Greenland and Antarctica over the last 100 years have led to different conclusions about past changes in solar activity. The reasons for this disagreement remain unresolved. We analyze a seasonally resolved 10Be record from a firn core (NEEM ice core project) in Northwestern Greenland for 1887-2002. By comparing the NEEM data to 10Be data from the NGRIP and Dye3 ice cores, we find that the Dye3 data after 1958 are significantly lower. These low values lead to a normalization problem in solar reconstructions when connecting 10Be variations to modern observations. Excluding these data strongly reduces the differences between solar reconstructions over the last 2000 years based on Greenland and Antarctic 10Be data. Furthermore, 10Be records from polar regions and group sunspot numbers do not support a substantial increase in solar activity for the 1937-1950 period as proposed by previous extensions of the neutron monitor data.This article is protected by copyright. All rights reserved.
- Published
- 2021
29. An unknown source of reactor radionuclides in the Baltic Sea revealed by multi-isotope fingerprints
- Author
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Peter Steier, Xiaolin Hou, Karin Hain, Haitao Zhang, Robin Golser, Vesa-Pekka Vartti, Ala Aldahan, Mats Eriksson, Göran Possnert, Gideon M. Henderson, and Jixin Qiao
- Subjects
inorganic chemicals ,Baltic States ,Radioactive Fallout ,Water Pollutants, Radioactive ,010504 meteorology & atmospheric sciences ,Science ,General Physics and Astronomy ,chemistry.chemical_element ,Annan geovetenskap och miljövetenskap ,010501 environmental sciences ,complex mixtures ,01 natural sciences ,Article ,General Biochemistry, Genetics and Molecular Biology ,Nuclear safeguards ,TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY ,Humans ,Seawater ,0105 earth and related environmental sciences ,Radioisotopes ,Sweden ,Radionuclide ,Multidisciplinary ,Waste management ,Isotope ,fungi ,technology, industry, and agriculture ,Sediment ,General Chemistry ,Uranium ,equipment and supplies ,Miljövetenskap ,Spent nuclear fuel ,Environmental sciences ,Ocean sciences ,Unknown Source ,Marine chemistry ,chemistry ,Baltic sea ,Environmental science ,Environmental Sciences ,Other Earth and Related Environmental Sciences - Abstract
We present an application of multi-isotopic fingerprints (i.e., 236U/238U, 233U/236U, 236U/129I and 129I/127I) for the discovery of previously unrecognized sources of anthropogenic radioactivity. Our data indicate a source of reactor 236U in the Baltic Sea in addition to inputs from the two European reprocessing plants and global fallout. This additional reactor 236U may come from unreported discharges from Swedish nuclear research facilities as supported by high 236U levels in sediment nearby Studsvik, or from accidental leakages of spent nuclear fuel disposed on the Baltic seafloor, either reported or unreported. Such leakages would indicate problems with the radiological safety of seafloor disposal, and may be accompanied by releases of other radionuclides. The results demonstrate the high sensitivity of multi-isotopic tracer systems, especially the 233U/236U signature, to distinguish environmental emissions of unrevealed radioactive releases for nuclear safeguards, emergency preparedness and environmental tracer studies., Anthropogenic activities lead to the accumulation of radioactive substances in the environment. Here the authors use multi-isotopic fingerprints of uranium and iodine to discover a previously unknown source of reactor uranium in the Baltic Sea, likely sourced from a Swedish nuclear facility.
- Published
- 2021
30. Supplementary material to 'CASCADE – The Circum-Arctic Sediment CArbon DatabasE'
- Author
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Jannik Martens, Evgeny Romankevich, Igor Semiletov, Birgit Wild, Bart van Dongen, Jorien Vonk, Tommaso Tesi, Natalia Shakhova, Oleg V. Dudarev, Denis Kosmach, Alexander Vetrov, Leopold Lobkovsky, Nikolay Belyaev, Robie Macdonald, Anna J. Pieńkowski, Timothy I. Eglinton, Negar Haghipour, Salve Dahle, Michael L. Carroll, Emmelie K. L. Åström, Jacqueline M. Grebmeier, Lee W. Cooper, Göran Possnert, and Örjan Gustafsson
- Published
- 2020
31. Holocene monsoon dynamics at Kunlun Pass on the northeastern Qinghai-Tibet Plateau
- Author
-
Minjie Zheng, Peng Yi, Xuegao Chen, Zhongbo Yu, Qingbai Wu, Göran Possnert, Markus Czymzik, Huijun Jin, Ala Aldahan, Peng Chen, Dongliang Luo, and Jinguo Wang
- Subjects
geography ,Environmental Engineering ,Plateau ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Atmospheric circulation ,Flux ,Westerlies ,010501 environmental sciences ,Before Present ,Monsoon ,01 natural sciences ,Pollution ,Environmental Chemistry ,Physical geography ,Waste Management and Disposal ,Deposition (chemistry) ,Geology ,Holocene ,0105 earth and related environmental sciences - Abstract
Various proxy records have been used for the understanding of environmental and climate variations during the Holocene. Here, for the first time, we use meteoric 10Be isotope measurements performed on sediments from a drill core collected at the Kunlun Pass (KP) on the northeastern Qinghai-Tibet Plateau (NETP) to investigate hydroclimate changes during the Holocene. The 10Be flux suggests relative low levels in the Early Holocene, followed by a sharp increase to high values at around 4 ka BP (4 ka BP = 4000 years before present). Afterwards, the 10Be flux remains on a high level during the Late Holocene, but decreases slightly towards today. These 10Be deposition patterns are compared to moisture changes in regions dominated by the Indian Summer Monsoon (ISM), East Asian Summer Monsoon (EASM), and the Westerlies. Different from the gradual changes in monsoon patterns, the 10Be data reveal low levels during the Early Holocene until ~4 ka BP when an obvious increase is indicated and a relative high level continues to this day, which is relatively more in agreement with patterns of the Westerlies. This finding provides a new evidence for a shift in the dominant pattern of atmospheric circulation at the KP region from a more monsoonal one to one dominated by the Westerlies. Our results improve the understanding of non-stationary interactions and spatial relevance of the EASM, the ISM and the Westerlies on the Qinghai-Tibet Plateau.
- Published
- 2020
32. A previously unknown source of reactor radionuclides in the Baltic Sea, identified by 233, 236, 238U and 127, 129I multi-fingerprinting
- Author
-
Ala Aldahan, Peter Steier, Mats Eriksson, Göran Possnert, Haitao Zhang, Jixin Qiao, Xiaolin Hou, Vesa-Pekka Vartti, Gideon M. Henderson, and Karin Hain
- Subjects
Radionuclide ,Oceanography ,Unknown Source ,Baltic sea ,TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY ,Environmental science - Abstract
We present the first application of multi-isotopic fingerprints (i.e., 236U/238U, 233U/236U, 236U/129I and 129I/127I) for the discovery of unrevealed radioactive sources. Our data indicate that, besides the reactor signature from the two European reprocessing plants and global fallout signature, there must be a previously undiscovered additional reactor 236U source in the Baltic Sea. This reactor 236U may come from unreported discharges from nuclear research facilities in Sweden, or it may come from accidental leakage from disposal of spent nuclear fuel on the Baltic seafloor, either reported or unreported. Such leakage would indicate potential problems with the safety of seafloor disposal, and may be accompanied by leakage of other radionuclides. The results demonstrate the high sensitivity of the multi-isotopic tracer systems, especially the newly accessible 233U/236U signature, to distinguish environmental emissions of unrevealed historical or present radioactive releases for nuclear safeguard and emergency preparedness, as well as tracing environmental processes from the releasing sites.
- Published
- 2020
33. Radionuclide wiggle matching reveals a nonsynchronous early Holocene climate oscillation in Greenland and western Europe around a grand solar minimum
- Author
-
Florian Mekhaldi, Celia Martín-Puertas, Markus Czymzik, Svante Björck, Achim Brauer, Jesper Sjolte, Ala Aldahan, Göran Possnert, Florian Adolphi, and Raimund Muscheler
- Subjects
Solar minimum ,lcsh:GE1-350 ,Global and Planetary Change ,Varve ,Climate Research ,Stratigraphy ,Anomaly (natural sciences) ,Climate oscillation ,lcsh:Environmental protection ,Paleontology ,Klimatforskning ,Preboreal ,Ice core ,lcsh:Environmental pollution ,Climatology ,lcsh:TD172-193.5 ,Wiggle matching ,lcsh:TD169-171.8 ,Geology ,Holocene ,lcsh:Environmental sciences - Abstract
Several climate oscillations have been reported from the early Holocene superepoch, the best known of which is the Preboreal oscillation (PBO). It is still unclear how the PBO and the number of climate oscillations observed in Greenland ice cores and European terrestrial records are related to one another. This is mainly due to uncertainties in the chronologies of the records. Here, we present new, high-resolution 10Be concentration data from the varved Meerfelder Maar sediment record in Germany, spanning the period 11 310–11 000 years BP. These new data allow us to synchronize this well-studied record, as well as Greenland ice core records, with the IntCal13 timescale via radionuclide wiggle matching. In doing so, we show that the climate oscillations identified in Greenland and Europe between 11 450 and 11 000 years BP were not synchronous but terminated and began, respectively, with the onset of a grand solar minimum. A similar spatial anomaly pattern is found in a number of modeling studies on solar forcing of climate in the North Atlantic region. We further postulate that freshwater delivery to the North Atlantic would have had the potential to amplify solar forcing through a slowdown of the Atlantic meridional overturning circulation (AMOC) reinforcing surface air temperature anomalies in the region.
- Published
- 2020
34. Solar and meteorological influences on seasonal atmospheric
- Author
-
Minjie, Zheng, Jesper, Sjolte, Florian, Adolphi, Ala, Aldahan, Göran, Possnert, Mousong, Wu, and Raimund, Muscheler
- Subjects
Europe ,Meteorology ,Air Pollutants, Radioactive ,Atmosphere ,Seasons - Abstract
Assessing the transport of natural radionuclides in the atmosphere provides a powerful tool to study air mass circulation. Here, we investigated the seasonal atmospheric distribution of the naturally produced
- Published
- 2020
35. Reconstruction of geomagnetic dipole moment variations for the last glacial period based on cosmogenic radionuclides from Greenland ice cores
- Author
-
Minjie Zheng, Anna Sturevik-Storm, Ala Aldahan, Raimund Muscheler, Florian Adolphi, Göran Possnert, and Andreas Nilsson
- Subjects
Moment (mathematics) ,Radionuclide ,Dipole ,Earth's magnetic field ,Ice core ,Glacial period ,Geophysics ,Geology - Abstract
Geomagnetic dipole moment variations, for example associated with polarity reversals and excursions, are linked to changes in cosmogenic radionuclide production rates. Therefore, it is possible to reconstruct past changes in the dipole moment based on cosmogenic radionuclide records from natural archives such as ice cores. Here we present a geomagnetic dipole moment reconstruction based on 10Be and 36Cl data from two Greenland ice cores over the period from 11.7 ka to 108 ka BP (before present AD 1950). We find significant correlations between the cosmogenic radionuclides and climate proxies which may be due to the common transport and deposition processes of these species. In an attempt to minimize climate-related variations in our dipole moment reconstruction, we apply a multi-linear correction method by removing common variability between 10Be and 36Cl and climate parameters (accumulation, δ18O and aerosol data) from the radionuclide records. The comparison of the resulting cosmogenic radionuclide-based dipole reconstruction with independent geomagnetic field records shows good agreement. This validates the use of cosmogenic radionuclides in ice cores to reconstruct past geomagnetic dipole moment variations after correction for the climate effect.
- Published
- 2020
36. Solar and climate signals revealed by seasonal Be-10 data from the NEEM ice core project for the neutron monitor period
- Author
-
Florian Adolphi, Mousong Wu, Peng Chen, Ala Aldahan, Jesper Sjolte, Raimund Muscheler, Göran Possnert, and Minjie Zheng
- Subjects
Eemian ,Neutron monitor ,Climate Research ,010504 meteorology & atmospheric sciences ,Atmospheric circulation ,Firn ,cosmogenic radionuclides ,seasonally resolved Be-10 ,010502 geochemistry & geophysics ,Atmospheric sciences ,01 natural sciences ,Solar cycle ,Klimatforskning ,Geophysics ,Ice core ,Space and Planetary Science ,Geochemistry and Petrology ,NEEM firn core ,Earth and Planetary Sciences (miscellaneous) ,Tropopause ,Deposition (chemistry) ,climate and solar signal ,Geology ,0105 earth and related environmental sciences - Abstract
Be-10 in ice cores has been instrumental for reconstructing past changes in solar activity prior to direct observations. For a robust use of these records, it is pivotal to understand the Be-10 transport and deposition. However, there are only few high-resolution seasonal Be-10 data longer than one full solar cycle (11 years) that could enable a quantification of the influences of atmospheric circulation and deposition processes on the Be-10 signal in ice. Here we present a seasonally resolved Be-10 data set covering the neutron monitor period (1951-2002) from a firn core connected to the NEEM (North Greenland Eemian Ice Drilling) project. The results suggest that both summer and winter Be-10 reflect the production signal induced by solar modulation of galactic cosmic rays. However, superimposed on this solar signal we find additional meteorologically driven influences on Be-10 transport and deposition. We found that the tropopause pressure over 30 degrees N represents an important factor influencing NEEM Be-10 concentrations on seasonal and annual scales. Be-10 deposited in summer also correlates significantly with the tropopause pressure over Greenland suggesting a direct contribution of stratospheric intrusions during summer to the Be-10 deposition in Greenland. To correct for these transport/deposition influences, we apply a first-order correction to the Be-10 data using a multi-linear regression model. The "climate-corrected" Be-10 data shows a comparable skill for reconstructing production rate changes as the Be-10 composite record from five different ice cores in Greenland. The results suggest that the correction approach can be a complementary method to the stacking to better isolate the production rate signal from the Be-10 data when only limited data are available.
- Published
- 2020
37. Diploid Hepatocytes Drive Physiological Liver Renewal in Adult Humans
- Author
-
Paula Heinke, Mehran Salehpour, Lutz Brusch, Thilo Welsch, Henrik Druid, Julian Rode, Olaf Bergmann, Fabian Rost, Joshua Feddema, Göran Possnert, and Kanar Alkass
- Subjects
medicine.anatomical_structure ,Polyploid ,Human liver ,Hepatocyte ,Liver cell ,medicine ,Ploidy ,Biology ,Polyploid Cells ,Metabolic activity ,Homeostasis ,Cell biology - Abstract
Physiological liver cell replacement is central to maintaining the organ's high metabolic activity, although its characteristics are difficult to study in humans. Using retrospective 14 C birth dating of cells, we report that human hepatocytes show continuous and lifelong turnover, maintaining the liver a young organ (average age < 3 years ). Hepatocyte renewal is highly dependent on the ploidy level. Diploid hepatocytes show an seven-fold higher annual exchange rate than polyploid hepatocytes. These observations support the view that physiological liver cell renewal in humans is mainly dependent on diploid hepatocytes, whereas polyploid cells are compromised in their ability to divide. Moreover, cellular transitions between these two subpopulations are limited, with minimal contribution to the respective other ploidy class under homeostatic conditions. With these findings, we present a new integrated model of liver cell generation in humans that provides fundamental insights into liver cell turnover dynamics.
- Published
- 2020
38. Circulation of Circumpolar Deep Water and marine environment traced by 127I and 129I speciation in the Amundsen Sea Polynya, Antarctica
- Author
-
Göran Possnert, Xiaolin Hou, Shan Xing, Ala Aldahan, and Keliang Shi
- Subjects
Water mass ,010504 meteorology & atmospheric sciences ,Health, Toxicology and Mutagenesis ,010501 environmental sciences ,01 natural sciences ,Ice shelf ,Amundsen sea polynya ,Circumpolar Deep Water ,Circumpolar deep water ,Phytoplankton ,Sea ice ,Environmental Chemistry ,SDG 14 - Life Below Water ,Waste Management and Disposal ,Marine environment ,0105 earth and related environmental sciences ,Iodine-129 ,geography ,geography.geographical_feature_category ,Continental shelf ,Iodine species ,General Medicine ,Pollution ,Oceanography ,Environmental science ,Upwelling ,Seawater - Abstract
The long-lived anthropogenic 129I released from human nuclear activities has been widely employed as an effective oceanographic tracer to investigate circulation of water masses in marine environment. Depth profiles of seawater collected from the Amundsen Sea Polynya, Antarctica were analyzed for total 129I and 127I, as well as their species of iodide and iodate. The measured 129I concentrations ((1.15–3.43) × 106 atoms/L) and 129I/127I atomic ratios ((0.53–1.19) × 10−11) indicate that anthropogenic 129I has not only reached the Antarctic surface marine environment but also the deep water due to a strong vertical mixing of water masses. The Circumpolar Deep Water (CDW) flowed southward along continental shelf towards the ice shelf zone (74.25°S) at a depth of 1025 m and then migrated upward and northward to the polynya and finally to the sea ice zone (71.95°S). The maximum upwelling depth of the CDW was around 200 m in the polynya. The source of 129I− in the polynya is predominantly the intrusion of source waters rather than the in-situ reduction of iodate by phytoplankton, implying a considerably slow reduction process of iodate to iodide in this region.
- Published
- 2020
39. 127I and 129I along a Transect in the English Channel
- Author
-
Peng He, Ala Aldahan, Xiaolin Hou, and Göran Possnert
- Published
- 2020
40. Supplementary material to 'Radionuclide wiggle-matching reveals a non-synchronous Early Holocene climate oscillation in Greenland and Western Europe around a grand solar minimum'
- Author
-
Florian Mekhaldi, Markus Czymzik, Florian Adolphi, Jesper Sjolte, Svante Björck, Ala Aldahan, Achim Brauer, Celia Martín-Puertas, Göran Possnert, and Raimund Muscheler
- Published
- 2019
41. Radionuclide wiggle-matching reveals a non-synchronous Early Holocene climate oscillation in Greenland and Western Europe around a grand solar minimum
- Author
-
Florian Mekhaldi, Markus Czymzik, Florian Adolphi, Jesper Sjolte, Svante Björck, Ala Aldahan, Achim Brauer, Celia Martín-Puertas, Göran Possnert, and Raimund Muscheler
- Abstract
Several climate events have been reported from the Early Holocene superepoch, the best known of these being the Preboreal oscillation (PBO). It is still unclear how the PBO and the number of climate events observed in Greenland ice cores and European terrestrial records are related to one another. This is mainly due to uncertainties in the chronologies of the records. Here, we present new high resolution 10Be concentration data from the varved Meerfelder Maar sediment record in Germany, spanning the period 11310–11000 years BP. These new data allow us to synchronize this well-studied record as well as Greenland ice-core records to the IntCal13 time-scale via radionuclide wiggle-matching. In doing so, we show that the climate oscillations identified in Greenland and Europe between 11450 and 11000 years BP were not synchronous but terminated and began, respectively, with the onset of a grand solar minimum. A similar spatial anomaly pattern is found in a number of modeling studies on solar forcing of climate in the North Atlantic region. We further postulate that freshwater delivery to the North Atlantic would have had the potential to amplify solar forcing through a slowdown of the Atlantic meridional overturning circulation (AMOC) reinforcing surface air temperature anomalies in the region.
- Published
- 2019
42. On the Holocene vegetation history of the Central Rila Mountains, Bulgaria: The palaeoecological record of peat bog Vodniza (2113 m)
- Author
-
Spassimir Tonkov, Elena Marinova, Elissaveta Bozilova, Göran Possnert, and Dolja Pavlova
- Subjects
010506 paleontology ,Peat ,010504 meteorology & atmospheric sciences ,biology ,Holocene climatic optimum ,Paleontology ,Picea abies ,Vegetation ,Pinus peuce ,biology.organism_classification ,01 natural sciences ,Geography ,Pinus mugo ,Physical geography ,Ecology, Evolution, Behavior and Systematics ,Holocene ,Tree line ,0105 earth and related environmental sciences - Abstract
Information on the Holocene vegetation history of the Central Rila Mountains for the last 10,000 years was obtained by means of pollen and fossil stomata analyses of a 500 cm core retrieved from peat bog Vodniza (2113 m a.s.l.), and supported by radiocarbon chronology. The early Holocene afforestation started with an initial Betula phase with stands of Juniperus and Pinus which occupied barren soils (10,000–8300 cal. yrs. BP) while deciduous oak forests with abundant Tilia , Ulmus , Acer , and later on Corylus , spread at lower elevations. During the Holocene climatic optimum (8300–6000 cal. yrs. BP) the conifers Pinus ( Pinus sylvestris , Pinus mugo , Pinus peuce ) and Abies expanded at the expense of the birch and oak forests. The tree line was running above 2100 m comparable to the present-day situation and started to descend after ca. 3200 cal. yrs. BP mostly due to human impact. The last tree which penetrated into the coniferous belt after 3400 cal. yrs. BP and reached altitudes of 2000–2100 m, confirmed by the find of fossil stomata, was Picea abies . Its maximal distribution was achieved between 2250 and 1100 cal. yrs. BP, alongside with some enlargement of beech communities. The first indications of stock-breeding and other human activities in the Central Rila Mountains were recorded since 3400–3200 cal. yrs. BP (Late Bronze Age). The vegetation reconstruction during the Holocene followed a pattern coherent with the information from the Northern Pirin and partly from the Western Rhodopes Mountains. The palaeoecological evidence from the Rila Mountains could be compared in broad lines with the high quality data obtained from the Romanian Carpathians by the application of multi-proxy research approach.
- Published
- 2018
43. Early Holocene human population events on the island of Gotland in the Baltic Sea (9200-3800 cal. BP)
- Author
-
Göran Possnert, Jan Apel, Jan Storå, and Paul Wallin
- Subjects
010506 paleontology ,education.field_of_study ,060102 archaeology ,biology ,Population size ,Population ,Littorina ,06 humanities and the arts ,biology.organism_classification ,01 natural sciences ,Archaeology ,law.invention ,Geography ,Beaker ,law ,0601 history and archaeology ,Radiocarbon dating ,Physical geography ,education ,Mesolithic ,Holocene ,0105 earth and related environmental sciences ,Earth-Surface Processes ,Marine transgression - Abstract
The summed probability distribution of 162 radiocarbon dates from Gotland was analysed with reference to archaeological and environmental data in order to evaluate possible variations in settlement intensity on the island. The data indicated variations in demographic development on the island, with probably several different colonization events and external influences; the pioneer settlement reached the island around 9200 cal. BP. After the initial colonization, the radiocarbon dates were rather evenly distributed until around 7700–7600 cal. BP, then there was a drop in the number of dates between 8300 and 8000 cal. BP that may be associated with the 8200 cold event. A marked decline in the number of dates between 7600 and 6000 cal. BP may be associated initially with the Littorina I transgression, but this transgression cannot explain why the Late Mesolithic period is not well represented on Gotland: the climatic development was favourable but did not result in increased human activity. The number of radiocarbon dates indicated that the population size remained low until around 6000 cal. BP, after which there was a gradual increase that reached a first ‘threshold’ after 5600 cal. BP and a second ‘threshold’ after 4500 cal. BP. The first apparent population increase was associated with the appearance of the Funnel Beaker Culture (FBC) and the second with Pitted Ware Culture (PWC) complexes. A decline in the number of dates occurred after 4300 cal. BP, i.e. towards the Late Neolithic. There was an association between the frequency distributions of the radiocarbon dates and the number of stray finds from different time periods but any correlation was not straightforward.
- Published
- 2018
44. Comparison of measurement and modeling results of the global 10Be flux in topsoil
- Author
-
Z. B. Yu, Peng Yi, Vincent de Paul Mugwaneza, Ala Aldahan, Göran Possnert, and Peng Chen
- Subjects
Topsoil ,010504 meteorology & atmospheric sciences ,Soil test ,Health, Toxicology and Mutagenesis ,Public Health, Environmental and Occupational Health ,010502 geochemistry & geophysics ,Atmospheric sciences ,01 natural sciences ,Pollution ,Analytical Chemistry ,Data modeling ,Atmosphere ,Flux (metallurgy) ,Nuclear Energy and Engineering ,Soil water ,Erosion ,Environmental science ,Radiology, Nuclear Medicine and imaging ,Scale (map) ,Spectroscopy ,0105 earth and related environmental sciences - Abstract
Soils are among the major terrestrial reservoirs of atmospheric 10Be isotope and provide information of landscape evolution history. Despite this importance, there is no overview of the global soil 10Be fluxes in topsoil that is linked with atmospheric flux models. A comparison between measured (in topsoil) and atmospherically modeled 10Be fluxes is presented here. The data show relatively good agreement in the latitudinal trends. This feature demonstrates the potential to use the modeling data in estimating soil development/erosion rates in large scale basins where extensive 10Be measurements can be limited.
- Published
- 2017
45. Antibody-secreting plasma cells persist for decades in human intestine
- Author
-
Espen S. Baekkevold, Ludvig M. Sollid, Jeff E. Mold, Hildur Sif Thorarensen, Ole Øyen, Einar Martin Aandahl, Sheraz Yaqub, Rune Horneland, Göran Possnert, Raquel Bartolome Casado, Omri Snir, Frode L. Jahnsen, Lisa Richter, Jonas Frisén, Pedro Réu, Vemund Paulsen, Ole J. B. Landsverk, and Mehran Salehpour
- Subjects
Adult ,Male ,0301 basic medicine ,medicine.medical_specialty ,Adolescent ,Antigens, CD19 ,Plasma Cells ,Immunology ,behavioral disciplines and activities ,Organ transplantation ,CD19 ,03 medical and health sciences ,Antigen ,Immunity ,medicine ,Humans ,Immunology and Allergy ,Antibody-Producing Cells ,Child ,Research Articles ,Aged ,Aged, 80 and over ,biology ,Brief Definitive Report ,Middle Aged ,humanities ,Small intestine ,3. Good health ,Intestines ,030104 developmental biology ,medicine.anatomical_structure ,Ageing ,biology.protein ,Leukocyte Common Antigens ,Female ,Bone marrow ,Antibody - Abstract
This study provides a definite answer to the long-standing question concerning the longevity of the secretory antibody response. Landsverk et al. show that antigenic attrition affects a minor plasma cell subset and that distinct plasma cells are likely maintained for life in the human small intestine., Plasma cells (PCs) produce antibodies that mediate immunity after infection or vaccination. In contrast to PCs in the bone marrow, PCs in the gut have been considered short lived. In this study, we studied PC dynamics in the human small intestine by cell-turnover analysis in organ transplants and by retrospective cell birth dating measuring carbon-14 in genomic DNA. We identified three distinct PC subsets: a CD19+ PC subset was dynamically exchanged, whereas of two CD19− PC subsets, CD45+ PCs exhibited little and CD45− PCs no replacement and had a median age of 11 and 22 yr, respectively. Accumulation of CD45− PCs during ageing and the presence of rotavirus-specific clones entirely within the CD19− PC subsets support selection and maintenance of protective PCs for life in human intestine.
- Published
- 2017
46. Deposition rates and 14C apparent ages of Holocene sediments in the Bothnian Bay of the Gulf of Bothnia using paleomagnetic dating as a reference
- Author
-
Johan Ingri, Anders Widerlund, Thongchai Suteerasak, Göran Possnert, and Sten-åke Elming
- Subjects
Paleomagnetism ,010504 meteorology & atmospheric sciences ,Brackish water ,Geochemistry ,Geology ,Crust ,010502 geochemistry & geophysics ,Oceanography ,01 natural sciences ,law.invention ,Salinity ,Tectonic uplift ,Geochemistry and Petrology ,law ,Radiocarbon dating ,Bay ,Holocene sediments ,0105 earth and related environmental sciences - Abstract
Three 6-m-long cores of sediments were collected in the northern, middle and southern part of the Bothnian Bay. The sediments were dated by paleomagnetic dating techniques, constrained by magnetic properties and geochemical data. The results indicate the ages of the sediments in the bottom part of the cores in the northern, middle and southern parts of the Bothnian Bay to be approximately 5300 years BP, 5350 years BP and 3500 years BP, respectively. The deposition rate calculated from the estimated ages at various depths show that the deposition rate was generally in the range 0.5–1.5 mm/year but it was higher in the southern part than in the middle and northern parts of the bay. There was a significant increase in the deposition rate at ca 2200 years BP, recorded in all three cores, a rate varying between 2.47 and 3.07 mm/year and lasting until ca 1840 years BP. A proposed constant uplift rate of the crust during the period ca 5500 years BP to present is thus not reflected by a constant deposition rate. The peaks in deposition rates at ca 2200–1840 years BP were followed by a decrease in salinity. This phenomenon is suggested to be caused by crustal uplift, with a threshold being formed in the southern part of the bay, thereby increasing the reactivation of bottom sediments and reducing the inflow of brackish water from the Bothnian Sea. The 14C ages of the sediments reveal differences in age compared with the paleomagnetic ages. In the southern core, the 14C ages are ca 1350 years older, and in the north, the age offset is mixed. The reactivation and re-deposition of sediments is argued to be the reason for the apparent 14C age differences. This finding demonstrates that 14C cannot be used for the dating of Bothnian Bay sediments unless the radiocarbon age offset has been determined.
- Published
- 2017
47. Cell generation dynamics underlying naïve T cell homeostasis in adult humans
- Author
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Jakob Michaëlsson, Samuel Bernard, Axel Olin, Jeff E. Mold, Petter Brodin, Sanket Rane, Azadeh Khosravi, Pedro Réu, Göran Possnert, Jonas Frisén, Mehran Salehpour, Andrew J. Yates, Karolinska Institutet [Stockholm], Center for Neuroscience and Cell Biology (CNC) (CNC), University of Coimbra [Portugal] (UC)-Neuroscience Research Domain, Multi-scale modelling of cell dynamics : application to hematopoiesis (DRACULA), Institut Camille Jordan [Villeurbanne] (ICJ), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre de génétique et de physiologie moléculaire et cellulaire (CGPhiMC), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Columbia University Medical Center (CUMC), Columbia University [New York], Albert Einstein College of Medicine [New York], Department of Cell and Molecular Biology [Stockholm], Department of Physics and Astronomy [Uppsala], Uppsala University, Angström Laboratory, Centre de génétique et de physiologie moléculaire et cellulaire (CGPhiMC), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut Camille Jordan (ICJ), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
CD4-Positive T-Lymphocytes ,Male ,0301 basic medicine ,Aging ,Physiology ,medicine.medical_treatment ,Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy) ,CD8-Positive T-Lymphocytes ,Lymphocyte Activation ,Biochemistry ,White Blood Cells ,0302 clinical medicine ,Animal Cells ,Medicine and Health Sciences ,Homeostasis ,Cytotoxic T cell ,Cell Cycle and Cell Division ,Biology (General) ,Phosphorylation ,Post-Translational Modification ,0303 health sciences ,Thymic involution ,T Cells ,General Neuroscience ,Repertoire ,NF-kappa B ,Gene Expression Regulation, Developmental ,Middle Aged ,Thymus ,3. Good health ,Cell biology ,Platelet Endothelial Cell Adhesion Molecule-1 ,medicine.anatomical_structure ,Cell Processes ,[SDV.IMM]Life Sciences [q-bio]/Immunology ,Female ,Cellular Types ,Signal transduction ,General Agricultural and Biological Sciences ,Signal Transduction ,Research Article ,Adult ,Naive T cell ,QH301-705.5 ,Immune Cells ,T cell ,Immunology ,[MATH.MATH-DS]Mathematics [math]/Dynamical Systems [math.DS] ,Cytotoxic T cells ,Thymus Gland ,Biology ,Research and Analysis Methods ,General Biochemistry, Genetics and Molecular Biology ,Immunophenotyping ,03 medical and health sciences ,medicine ,Humans ,Adults ,Cell Lineage ,Molecular Biology Techniques ,Molecular Biology ,Transcription factor ,Medicinsk bioteknologi (med inriktning mot cellbiologi (inklusive stamcellsbiologi), molekylärbiologi, mikrobiologi, biokemi eller biofarmaci) ,Aged ,Cell Proliferation ,030304 developmental biology ,Cloning ,Blood Cells ,General Immunology and Microbiology ,Interleukin-7 ,Growth factor ,Biology and Life Sciences ,Proteins ,Cell Biology ,030104 developmental biology ,Age Groups ,Immune System ,People and Places ,Population Groupings ,Physiological Processes ,030217 neurology & neurosurgery ,CD8 ,030215 immunology - Abstract
Thymic involution and proliferation of naive T cells both contribute to shaping the naive T-cell repertoire as humans age, but a clear understanding of the roles of each throughout a human life span has been difficult to determine. By measuring nuclear bomb test–derived 14C in genomic DNA, we determined the turnover rates of CD4+ and CD8+ naive T-cell populations and defined their dynamics in healthy individuals ranging from 20 to 65 years of age. We demonstrate that naive T-cell generation decreases with age because of a combination of declining peripheral division and thymic production during adulthood. Concomitant decline in T-cell loss compensates for decreased generation rates. We investigated putative mechanisms underlying age-related changes in homeostatic regulation of CD4+ naive T-cell turnover, using mass cytometry to profile candidate signaling pathways involved in T-cell activation and proliferation relative to CD31 expression, a marker of thymic proximity for the CD4+ naive T-cell population. We show that basal nuclear factor κB (NF-κB) phosphorylation positively correlated with CD31 expression and thus is decreased in peripherally expanded naive T-cell clones. Functionally, we found that NF-κB signaling was essential for naive T-cell proliferation to the homeostatic growth factor interleukin (IL)-7, and reduced NF-κB phosphorylation in CD4+CD31− naive T cells is linked to reduced homeostatic proliferation potential. Our results reveal an age-related decline in naive T-cell turnover as a putative regulator of naive T-cell diversity and identify a molecular pathway that restricts proliferation of peripherally expanded naive T-cell clones that accumulate with age., Our pool of naive T cells is critical for protection against new infections and cancers. By measuring remnant 14C from 1960s nuclear bomb blasts that has been incorporated into cellular DNA, this study defines the average age of the naive T-cell pool in healthy adults, revealing the slow, regulated turnover of the naive T-cell pool, supporting its maintenance for a human lifetime.
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- 2019
48. Multiradionuclide evidence for an extreme solar proton event around 2,610 B.P. (∼660 BC)
- Author
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Marcus Christl, Edouard Bard, Ala Aldahan, Paschal O’Hare, Hans-Arno Synal, John R. Southon, Jürg Beer, Grant M. Raisbeck, Raimund Muscheler, Florian Mekhaldi, Junghun Park, Emma Anderberg, Simon Fahrni, Florian Adolphi, Göran Possnert, Department of Geology [Lund], Lund University [Lund], Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Swiss Federal Insitute of Aquatic Science and Technology [Dübendorf] (EAWAG), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), Laboratory of Ion Beam Physics, Angström Laboratory, Uppsala University, Department of Earth System Science [Irvine] (ESS), University of California [Irvine] (UCI), University of California-University of California, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), University of California [Irvine] (UC Irvine), University of California (UC)-University of California (UC), Collège de France - Chaire Evolution du climat et de l'océan, Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), and Chaire Evolution du climat et de l'océan
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Solar proton ,Radionuclide ,Multidisciplinary ,010504 meteorology & atmospheric sciences ,Conjunction (astronomy) ,Event (relativity) ,Lead (sea ice) ,solar storms ,ice cores ,[SDU.STU]Sciences of the Universe [physics]/Earth Sciences ,Atmospheric sciences ,01 natural sciences ,solar proton events ,Earth, Atmospheric, and Planetary Sciences ,Ice core ,13. Climate action ,Physical Sciences ,0103 physical sciences ,Energy spectrum ,Environmental science ,010303 astronomy & astrophysics ,radionuclides ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,Production rate - Abstract
Significance This study provides evidence of an enormous solar storm around 2,610 B.P. It is only the third such event reliably documented and is comparable with the strongest event detected at AD 774/775. The event of 2,610 years B.P. stands out because of its particular signature in the radionuclide data [i.e., carbon-14 (14C) data alone does not allow for an unequivocal detection of the event]. It illustrates that present efforts to find such events based solely on 14C data likely lead to an underestimated number of such potentially devastating events for our society. In addition to 14C data, high-resolution records of beryllium-10 and chlorine-36 are crucial for reliable estimates of the occurrence rate and the properties of past solar proton events., Recently, it has been confirmed that extreme solar proton events can lead to significantly increased atmospheric production rates of cosmogenic radionuclides. Evidence of such events is recorded in annually resolved natural archives, such as tree rings [carbon-14 (14C)] and ice cores [beryllium-10 (10Be), chlorine-36 (36Cl)]. Here, we show evidence for an extreme solar event around 2,610 years B.P. (∼660 BC) based on high-resolution 10Be data from two Greenland ice cores. Our conclusions are supported by modeled 14C production rates for the same period. Using existing 36Cl ice core data in conjunction with 10Be, we further show that this solar event was characterized by a very hard energy spectrum. These results indicate that the 2,610-years B.P. event was an order of magnitude stronger than any solar event recorded during the instrumental period and comparable with the solar proton event of AD 774/775, the largest solar event known to date. The results illustrate the importance of multiple ice core radionuclide measurements for the reliable identification of short-term production rate increases and the assessment of their origins.
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- 2019
49. Publisher Correction: Dynamics of oligodendrocyte generation in multiple sclerosis
- Author
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Embla Steiner, Mehdi Djelloul, Jonas Frisén, Lou Brundin, Maggie S. Y. Yeung, Göran Possnert, Samuel Bernard, and Mehran Salehpour
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0301 basic medicine ,Multidisciplinary ,Computer science ,Published Erratum ,Multiple sclerosis ,medicine.disease ,Oligodendrocyte ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Error bar ,medicine ,Neuroscience - Abstract
In this Letter, the vertical error bars were missing from Fig. 3b and 3c. This figure has been corrected online.
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- 2019
50. Dynamics of oligodendrocyte generation in multiple sclerosis
- Author
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Göran Possnert, Embla Steiner, Mehdi Djelloul, Samuel Bernard, Jonas Frisén, Lou Brundin, Mehran Salehpour, Maggie S. Y. Yeung, Karolinska Institutet [Stockholm], Multi-scale modelling of cell dynamics : application to hematopoiesis (DRACULA), Institut Camille Jordan [Villeurbanne] (ICJ), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre de génétique et de physiologie moléculaire et cellulaire (CGPhiMC), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Modélisation mathématique, calcul scientifique (MMCS), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Astronomy [Uppsala], Uppsala University, Angström Laboratory, Centre de génétique et de physiologie moléculaire et cellulaire (CGPhiMC), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut Camille Jordan (ICJ), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), and Institut Camille Jordan (ICJ)
- Subjects
0301 basic medicine ,Adult ,Male ,medicine.medical_specialty ,Aging ,Neurology ,Multiple Sclerosis ,Central nervous system ,[MATH.MATH-DS]Mathematics [math]/Dynamical Systems [math.DS] ,Cell Separation ,Biology ,White matter ,03 medical and health sciences ,Myelin ,0302 clinical medicine ,medicine ,Demyelinating disease ,Humans ,Remyelination ,Age of Onset ,Myelin Sheath ,Cell Proliferation ,Multidisciplinary ,Multiple sclerosis ,Cell Differentiation ,medicine.disease ,White Matter ,Oligodendrocyte ,Oligodendroglia ,030104 developmental biology ,medicine.anatomical_structure ,Case-Control Studies ,Female ,Neuroscience ,030217 neurology & neurosurgery - Abstract
International audience; Oligodendrocytes wrap nerve fibres in the central nervous system with layers of specialized cell membrane to form myelin sheaths1. Myelin is destroyed by the immune system in multiple sclerosis, but myelin is thought to regenerate and neurological function can be recovered. In animal models of demyelinating disease, myelin is regenerated by newly generated oligodendrocytes, and remaining mature oligodendrocytes do not seem to contribute to this process2,3,4. Given the major differences in the dynamics of oligodendrocyte generation and adaptive myelination between rodents and humans5,6,7,8,9, it is not clear how well experimental animal models reflect the situation in multiple sclerosis. Here, by measuring the integration of 14C derived from nuclear testing in genomic DNA10, we assess the dynamics of oligodendrocyte generation in patients with multiple sclerosis. The generation of new oligodendrocytes was increased several-fold in normal-appearing white matter in a subset of individuals with very aggressive multiple sclerosis, but not in most subjects with the disease, demonstrating an inherent potential to substantially increase oligodendrocyte generation that fails in most patients. Oligodendrocytes in shadow plaques—thinly myelinated lesions that are thought to represent remyelinated areas—were old in patients with multiple sclerosis. The absence of new oligodendrocytes in shadow plaques suggests that remyelination of lesions occurs transiently or not at all, or that myelin is regenerated by pre-existing, and not new, oligodendrocytes in multiple sclerosis. We report unexpected oligodendrocyte generation dynamics in multiple sclerosis, and this should guide the use of current, and the development of new, therapies.
- Published
- 2019
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