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Publications (10 of 644) Show all publications
Tonkov, S., Possnert, G. & Marinova, E. (2023). 66. Lake Vapsko-2, Rila Mountains (Bulgaria). Grana, 62(1), 70-72
Open this publication in new window or tab >>66. Lake Vapsko-2, Rila Mountains (Bulgaria)
2023 (English)In: Grana, ISSN 0017-3134, E-ISSN 1651-2049, Vol. 62, no 1, p. 70-72Article in journal, Editorial material (Other academic) Published
Place, publisher, year, edition, pages
Taylor & Francis, 2023
National Category
Geosciences, Multidisciplinary
Identifiers
urn:nbn:se:uu:diva-502366 (URN)10.1080/00173134.2022.2128864 (DOI)000888627100001 ()
Available from: 2023-05-29 Created: 2023-05-29 Last updated: 2023-05-29Bibliographically approved
He, P., Pang, H., Yang, Z., Li, S., Huang, Y., Hou, X., . . . Aldahan, A. (2022). 127I and 129I species in the English Channel and its adjacent areas: uncovering impact on the isotopes marine pathways. Water Research, 225, Article ID 119178.
Open this publication in new window or tab >>127I and 129I species in the English Channel and its adjacent areas: uncovering impact on the isotopes marine pathways
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2022 (English)In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 225, article id 119178Article in journal (Refereed) Published
Abstract [en]

Radioactive iodine-129 has been released from the La Hague nuclear fuel reprocessing facility (NRF) into the English Channel, but the distribution and transformation of the isotope species, and environmental consequences have not been fully characterized in the Channel. Here we present data on iodine isotopes (129I and 127I) species in surface water of the English Channel and the southern Celtic Sea. Compared to 127I species, the concentrations of 129I- and 129IO3-show more variations, but iodate is the major species for both 129I and 127I. Our data provide new information regarding iodide-iodate inter-conversion showing that water dilution and mixing are the main factors affecting the 127I and 129I species distribution in the Channel. Some reduction of iodate occurs within the English Channel and mainly in the west part because of biotic processes. The 129I species transformation is overall insignificant, especially in the eastern Channel, where a constant value of 129IO3- /129I is observed, which might characterize the La Hague wastewater signal. In the Celtic Sea, oxidation of iodide can be traced by 127I and 129I species. On a larger scale,129I generally experienced an oxidation process in the Atlantic Ocean, while in the coast of shallow shelf seas, new produced 129I- can be identified, especially in the German Bight and the Baltic Sea. The data of 129I species in the English Channel can provide estimate of redox rates in a much broader marine areas if the transit time of 129I from La Hague is well-defined. Furthermore, estimate of inventories for 129I and its species in the Channel, and fluxes of 129I species from the English Channel to the North Sea add important information to the geochemical cycle of 129I.

Place, publisher, year, edition, pages
Elsevier, 2022
Keywords
English Channel, Iodine species, Iodine isotopes, Seawater, 129I
National Category
Geochemistry
Identifiers
urn:nbn:se:uu:diva-487992 (URN)10.1016/j.watres.2022.119178 (DOI)000868492800004 ()36219893 (PubMedID)
Available from: 2022-11-10 Created: 2022-11-10 Last updated: 2022-11-10Bibliographically approved
Heinke, P., Rost, F., Rode, J., Trus, P., Simonova, I., Lazar, E., . . . Bergmann, O. (2022). Diploid hepatocytes drive physiological liver renewal in adult humans. CELL SYSTEMS, 13(6), 499-+
Open this publication in new window or tab >>Diploid hepatocytes drive physiological liver renewal in adult humans
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2022 (English)In: CELL SYSTEMS, ISSN 2405-4712, Vol. 13, no 6, p. 499-+Article in journal (Refereed) Published
Abstract [en]

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 <3 years). Hepatocyte renewal is highly dependent on the ploidy level. Diploid hepatocytes show more than 7-fold higher annual birth rates 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 diploid and polyploid hepatocytes are limited under homeostatic conditions. With these findings, we present an integrated model of homeostatic liver cell generation in humans that provides fundamental insights into liver cell turnover dynamics.

Place, publisher, year, edition, pages
ElsevierElsevier BV, 2022
National Category
Cell and Molecular Biology
Identifiers
urn:nbn:se:uu:diva-480004 (URN)10.1016/j.cels.2022.05.001 (DOI)000814124400006 ()35649419 (PubMedID)
Funder
Karolinska InstituteSwedish Research Council
Available from: 2022-07-06 Created: 2022-07-06 Last updated: 2024-01-15Bibliographically approved
Roeder, S. S., Burkardt, P., Rost, F., Rode, J., Brusch, L., Coras, R., . . . Huttner, H. B. (2022). Evidence for postnatal neurogenesis in the human amygdala. Communications Biology, 5(1), Article ID 366.
Open this publication in new window or tab >>Evidence for postnatal neurogenesis in the human amygdala
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2022 (English)In: Communications Biology, E-ISSN 2399-3642, Vol. 5, no 1, article id 366Article in journal (Refereed) Published
Abstract [en]

The human amygdala is involved in processing of memory, decision-making, and emotional responses. Previous studies suggested that the amygdala may represent a neurogenic niche in mammals. By combining two distinct methodological approaches, lipofuscin quantification and C-14-based retrospective birth dating of neurons, along with mathematical modelling, we here explored whether postnatal neurogenesis exists in the human amygdala. We investigated post-mortem samples of twelve neurologically healthy subjects. The average rate of lipofuscin-negative neurons was 3.4%, representing a substantial proportion of cells substantially younger than the individual. Mass spectrometry analysis of genomic C-14-concentrations in amygdala neurons compared with atmospheric C-14-levels provided evidence for postnatal neuronal exchange. Mathematical modelling identified a best-fitting scenario comprising of a quiescent and a renewing neuronal population with an overall renewal rate of >2.7% per year. In conclusion, we provide evidence for postnatal neurogenesis in the human amygdala with cell turnover rates comparable to the hippocampus. Lipofuscin labeling and (14) C retrospective birth-dating of neurons, along with mathematical modelling, here suggest continued postnatal neurogenesis in the human amygdala, rather than protracted maturation of developmentally generated neurons.

Place, publisher, year, edition, pages
Springer NatureSpringer Nature, 2022
National Category
Neurosciences
Identifiers
urn:nbn:se:uu:diva-474120 (URN)10.1038/s42003-022-03299-8 (DOI)000784972300004 ()35440676 (PubMedID)
Available from: 2022-05-09 Created: 2022-05-09 Last updated: 2024-01-15Bibliographically approved
Possnert, G. & El-Daoushy, F. (2022). PROFESSOR INGRID ULRIKA OLSSON (1927-2018): IN MEMORIAM. Radiocarbon, 64(3), 459-461, Article ID PII S0033822221001089.
Open this publication in new window or tab >>PROFESSOR INGRID ULRIKA OLSSON (1927-2018): IN MEMORIAM
2022 (English)In: Radiocarbon, ISSN 0033-8222, E-ISSN 1945-5755, Vol. 64, no 3, p. 459-461, article id PII S0033822221001089Article in journal (Refereed) Published
Place, publisher, year, edition, pages
Cambridge University PressCAMBRIDGE UNIV PRESS, 2022
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:uu:diva-483575 (URN)10.1017/RDC.2021.108 (DOI)000734685500001 ()
Available from: 2022-08-31 Created: 2022-08-31 Last updated: 2024-01-15Bibliographically approved
Tonkov, S. & Possnert, G. (2021). 55. Lake Ribno Banderishko, Pirin Mountains (Bulgaria). Grana, 60(5), 404-406
Open this publication in new window or tab >>55. Lake Ribno Banderishko, Pirin Mountains (Bulgaria)
2021 (English)In: Grana, ISSN 0017-3134, E-ISSN 1651-2049, Vol. 60, no 5, p. 404-406Article in journal (Refereed) Published
Place, publisher, year, edition, pages
Taylor & FrancisTaylor & Francis, 2021
National Category
Physical Geography
Identifiers
urn:nbn:se:uu:diva-468327 (URN)10.1080/00173134.2021.1902562 (DOI)000661692900001 ()
Available from: 2022-02-23 Created: 2022-02-23 Last updated: 2024-01-15Bibliographically approved
Qiao, J., Zhang, H., Steier, P., Hain, K., Hou, X., Vartti, V.-P., . . . Golser, R. (2021). An unknown source of reactor radionuclides in the Baltic Sea revealed by multi-isotope fingerprints. Nature Communications, 12(1), Article ID 823.
Open this publication in new window or tab >>An unknown source of reactor radionuclides in the Baltic Sea revealed by multi-isotope fingerprints
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2021 (English)In: Nature Communications, E-ISSN 2041-1723, Vol. 12, no 1, article id 823Article in journal (Refereed) Published
Abstract [en]

We present an application of multi-isotopic fingerprints (i.e., U-236/U-238, U-233/U-236, U-236/I-129 and I-129/I-127) for the discovery of previously unrecognized sources of anthropogenic radioactivity. Our data indicate a source of reactor U-236 in the Baltic Sea in addition to inputs from the two European reprocessing plants and global fallout. This additional reactor U-236 may come from unreported discharges from Swedish nuclear research facilities as supported by high U-236 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 U-233/U-236 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.

Place, publisher, year, edition, pages
Springer NatureNATURE RESEARCH, 2021
National Category
Environmental Sciences
Identifiers
urn:nbn:se:uu:diva-437895 (URN)10.1038/s41467-021-21059-w (DOI)000617499600025 ()33547296 (PubMedID)
Available from: 2021-03-19 Created: 2021-03-19 Last updated: 2024-01-15Bibliographically approved
Martens, J., Romankevich, E., Semiletov, I., Wild, B., van Dongen, B., Vonk, J., . . . Gustafsson, Ö. (2021). CASCADE: The Circum-Arctic Sediment CArbon DatabasE. Earth System Science Data, 13(6), 2561-2572
Open this publication in new window or tab >>CASCADE: The Circum-Arctic Sediment CArbon DatabasE
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2021 (English)In: Earth System Science Data, ISSN 1866-3508, E-ISSN 1866-3516, Vol. 13, no 6, p. 2561-2572Article in journal (Refereed) Published
Abstract [en]

Biogeochemical cycling in the semi-enclosed Arctic Ocean is strongly influenced by land–ocean transport of carbon and other elements and is vulnerable to environmental and climate changes. Sediments of the Arctic Ocean are an important part of biogeochemical cycling in the Arctic and provide the opportunity to study present and historical input and the fate of organic matter (e.g., through permafrost thawing).

Comprehensive sedimentary records are required to compare differences between the Arctic regions and to study Arctic biogeochemical budgets. To this end, the Circum-Arctic Sediment CArbon DatabasE (CASCADE) was established to curate data primarily on concentrations of organic carbon (OC) and OC isotopes (δ13C, Δ14C) yet also on total N (TN) as well as terrigenous biomarkers and other sediment geochemical and physical properties. This new database builds on the published literature and earlier unpublished records through an extensive international community collaboration.

This paper describes the establishment, structure and current status of CASCADE. The first public version includes OC concentrations in surface sediments at 4244 oceanographic stations including 2317 with TN concentrations, 1555 with δ13C-OC values and 268 with Δ14C-OC values and 653 records with quantified terrigenous biomarkers (high-molecular-weight n-alkanes, n-alkanoic acids and lignin phenols). CASCADE also includes data from 326 sediment cores, retrieved by shallow box or multi-coring, deep gravity/piston coring, or sea-bottom drilling. The comprehensive dataset reveals large-scale features of both OC content and OC sources between the shelf sea recipients. This offers insight into release of pre-aged terrigenous OC to the East Siberian Arctic shelf and younger terrigenous OC to the Kara Sea. Circum-Arctic sediments thereby reveal patterns of terrestrial OC remobilization and provide clues about thawing of permafrost.

CASCADE enables synoptic analysis of OC in Arctic Ocean sediments and facilitates a wide array of future empirical and modeling studies of the Arctic carbon cycle. The database is openly and freely available online (https://doi.org/10.17043/cascade; Martens et al., 2021), is provided in various machine-readable data formats (data tables, GIS shapefile, GIS raster), and also provides ways for contributing data for future CASCADE versions. We will continuously update CASCADE with newly published and contributed data over the foreseeable future as part of the database management of the Bolin Centre for Climate Research at Stockholm University.

Place, publisher, year, edition, pages
Copernicus Publications, 2021
National Category
Climate Research
Identifiers
urn:nbn:se:uu:diva-447948 (URN)10.5194/essd-13-2561-2021 (DOI)000661356600001 ()
Funder
EU, European Research Council, CC-TOP 695331EU, Horizon 2020, 773421Swedish Research Council, 2017-01601Knut and Alice Wallenberg Foundation, 2011.0027The Research Council of Norway, 228107The Research Council of Norway, 223259
Available from: 2021-07-01 Created: 2021-07-01 Last updated: 2024-01-15Bibliographically approved
Zheng, M., Sturevik Storm, A., Nilsson, A., Adolphi, F., Aldahan, A., Possnert, G. & Muscheler, R. (2021). Geomagnetic dipole moment variations for the last glacial period inferred from cosmogenic radionuclides in Greenland ice cores via disentangling the climate and production signals. Quaternary Science Reviews, 258
Open this publication in new window or tab >>Geomagnetic dipole moment variations for the last glacial period inferred from cosmogenic radionuclides in Greenland ice cores via disentangling the climate and production signals
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2021 (English)In: Quaternary Science Reviews, ISSN 0277-3791, E-ISSN 1873-457X, Vol. 258Article in journal (Refereed) Published
Abstract [en]

The geomagnetic dipole moment (GDM) modulates the production rates of cosmogenic radionuclides via the shielding of galactic cosmic rays. Therefore, it is possible to use this linkage to reconstruct past changes in the GDM based on cosmogenic radionuclide records from natural archives such as ice cores. Here we present a GDM reconstruction based on 10Be and 36Cl data from two Greenland ice cores from 11.7 ka to 108 ka b2k (before A.D. 2000). We find that the cosmogenic radionuclide records reflect a mixture of climate and production effects that require separation to evaluate the changes in the GDM. To minimize climate-related variations on isotope data, we applied a multi-linear correction method by removing common variability between 10Be and 36Cl and climate parameters (accumulation rates, d18O and ion data) from radionuclide records. The resulting & ldquo;climate corrected & rdquo; radionuclide data are con-verted to GDM using a theoretical production model. Comparison of & ldquo;climate corrected & rdquo; radionuclides based GDM reconstructions with independent paleomagnetic-derived GDM records shows a good agreement. Furthermore, the & ldquo;climate correction & rdquo; leads to an improved agreement with GDM re-constructions than simply using radionuclide fluxes, lending support to the validity of our correction method to isolate production rate changes from ice core radionuclide records. With this correction method, we can extend the GDM reconstructions based on the cosmogenic radionuclides in ice cores to a period when there is a strong climate signal in the data. (c) 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). <comment>Superscript/Subscript Available</comment

Place, publisher, year, edition, pages
ElsevierPERGAMON-ELSEVIER SCIENCE LTD, 2021
Keywords
Quaternary, Glaciology, Greenland ice cores, Cosmogenic isotopes, Multi-linear correction, Geomagnetic dipole moment reconstruction
National Category
Climate Research
Identifiers
urn:nbn:se:uu:diva-443683 (URN)10.1016/j.quascirev.2021.106881 (DOI)000643687700011 ()
Funder
Swedish Research Council, 20138421Swedish Research Council, 201600218Swedish Research CouncilEU, FP7, Seventh Framework ProgrammeEU, FP7, Seventh Framework Programme
Available from: 2021-06-18 Created: 2021-06-18 Last updated: 2024-01-15Bibliographically approved
Chen, P., Yu, Z., Czymzik, M., Aldahan, A., Wang, J., Yi, P., . . . Wu, Q. (2021). Holocene monsoon dynamics at Kunlun Pass on the northeastern Qinghai-Tibet Plateau. Science of the Total Environment, 771, Article ID 145369.
Open this publication in new window or tab >>Holocene monsoon dynamics at Kunlun Pass on the northeastern Qinghai-Tibet Plateau
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2021 (English)In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 771, article id 145369Article in journal (Refereed) Published
Abstract [en]

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 Be-10 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 Be-10 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 Be-10 flux remains on a high level during the Late Holocene, but decreases slightly towards today. These Be-10 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 Be-10 data reveal low levels during the Early Holocene until similar to 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 fora shift in the dominant pattern of atmospheric circulation 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.

Place, publisher, year, edition, pages
ElsevierELSEVIER, 2021
Keywords
Asian Summer Monsoon, The Westerlies, Beryllium-10, Moisture variation, Atmospheric circulations
National Category
Climate Research Geology
Identifiers
urn:nbn:se:uu:diva-442174 (URN)10.1016/j.scitotenv.2021.145369 (DOI)000627895900100 ()33545484 (PubMedID)
Available from: 2021-05-17 Created: 2021-05-17 Last updated: 2024-01-15Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-4840-291x

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