A5077704792- Geology and Paleoclimatology Research
- Archaeology and ancient environmental studies
- Radioactive contamination and transfer
- Pleistocene-Era Hominins and Archaeology
- Radioactivity and Radon Measurements
- Isotope Analysis in Ecology
- Ion-surface interactions and analysis
- Marine and environmental studies
- Geological formations and processes
- Geomagnetism and Paleomagnetism Studies
- Methane Hydrates and Related Phenomena
- Ancient and Medieval Archaeology Studies
- Fusion materials and technologies
- Cryospheric studies and observations
- Nuclear Physics and Applications
- Magnetic confinement fusion research
- Nuclear Materials and Properties
- Arctic and Antarctic ice dynamics
- Semiconductor materials and devices
- Atmospheric and Environmental Gas Dynamics
- Integrated Circuits and Semiconductor Failure Analysis
- Mass Spectrometry Techniques and Applications
- Planetary Science and Exploration
- Geological Studies and Exploration
- Geological and Geochemical Analysis
Uppsala University
2014-2024
United Arab Emirates University
2009-2022
Chengdu University of Technology
2022
Royal Military Academy
2020
Herzen University
2020
Samara State University of Social Sciences and Education
2020
University of Helsinki
2020
KTH Royal Institute of Technology
2016
Institute of Plasma Physics
2013
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2013
On the basis of synchronization three carbon-14 (14C)-dated lacustrine sequences from Sweden with tree ring and ice core records, absolute age Younger Dryas-Preboreal climatic shift was determined to be 11,450 11,390 +/- 80 years before present. A 150-year-long cooling in early Preboreal, associated rising Delta14C values, is evident all records indicates an ocean ventilation change. This similar earlier deglacial coolings, box-model calculations suggest that they may have been result...
DNA from excrements can be amplified by means of the polymerase chain reaction. However, this has not been possible with ancient feces. Cross-links between reducing sugars and amino groups were shown to exist in a Pleistocene coprolite Gypsum Cave, Nevada. A chemical agent, N -phenacylthiazolium bromide, that cleaves such cross-links made it amplify sequences. Analyses these sequences showed is derived an extinct sloth, presumably Shasta ground sloth Nothrotheriops shastensis . Plant seven...
The retrieval of mitochondrial DNA (mtDNA) sequences from four Neandertal fossils Germany, Russia, and Croatia has demonstrated that these individuals carried closely related mtDNAs are not found among current humans. However, results do definitively resolve the question a possible contribution to gene pool modern humans since such might have been erased by genetic drift or continuous influx human into pool. A further concern is if some Neandertals mtDNA similar contemporaneous humans, may...
The hematopoietic system seeds the CNS with microglial progenitor cells during fetal period, but subsequent cell generation dynamics and maintenance of this population have been poorly understood. We report that microglia, unlike most other lineages, renew slowly at a median rate 28% per year, some microglia last for more than two decades. Furthermore, we find no evidence existence substantial quiescent long-lived cells, meaning in human brain is sustained by continuous slow turnover...
Abstract The origin of two large peaks in the atmospheric radiocarbon ( 14 C) concentration at AD 774/5 and 993/4 is still debated. There consensus, however, that these features can only be explained by an increase C production rate due to extraterrestrial event. Here we provide evidence were most likely produced extreme solar events, based on several new annually resolved 10 Be measurements from both Arctic Antarctic ice cores. Using core 36 Cl data pair with Be, further show events...
Plasma cells (PCs) produce antibodies that mediate immunity after infection or vaccination. In contrast to PCs in the bone marrow, gut have been considered short lived. this study, we studied PC dynamics human small intestine by cell-turnover analysis organ transplants and retrospective cell birth dating measuring carbon-14 genomic DNA. We identified three distinct subsets: a CD19+ subset was dynamically exchanged, whereas of two CD19- subsets, CD45+ exhibited little CD45- no replacement had...
Some glacial sediment samples recovered from beneath the West Antarctic ice sheet at stream B contain Quaternary diatoms and up to 10(8) atoms of beryllium-10 per gram. Other no only background levels (less than 10(6) gram). The occurrence young high concentrations grounded indicates that Ross Embayment was an open marine environment after a late Pleistocene collapse sheet.
Abstract The Vedde Ash Bed (mid-Younger Dryas) and the Saksunarvatn (early Holocene) are important regional stratigraphic event markers in North Atlantic, Norwegian Sea, adjacent land area. It is thus essential to date them as precisely possible. occurrence of reported for first time from western Norway, both tephras dated by AMS analyses terrestrial plant material lake sediment at Kråkenes. has been previously sites Norway about 10,600 yr B.P. obvious Younger Dryas sediments Kråkenes, its...
Abstract DNA was extracted from five coprolites, excavated in Gypsum Cave, Nevada and radiocarbon dated to approximately 11 000, 20 000 28 500 years bp. All coprolites contained mitochondrial sequences identical a sequence determined bone of the extinct ground sloth Nothrotheriops shastensis . A 157‐bp fragment chloroplast gene for large subunit ribulosebisphosphate carboxylase ( rbcL ) amplified boluses several hundred clones were sequenced. In addition, same sequenced 99 plant species that...
Despite the extensive use of 10 Be as most significant information source on past solar activity, there has been only one record (Dye‐3, Greenland) providing annual resolution over several centuries. Here we report a new spanning period 1389–1994 AD, measured in an ice core from NGRIP site Greenland. and Dye‐3 exhibits similar long‐term variability, although occasional short term differences between two sites indicate that at least high records are needed to assess local variations...
A dedicated detector system for heavy ion elastic recoil detection analysis at the Tandem Laboratory of Uppsala University is presented. Benefits combining a time-of-flight measurement with segmented anode gas ionization chamber are demonstrated. The capability species identification improved present system, compared to that obtained when using single solid state silicon full energy signal. enables separation light elements, up Neon, based on atomic number while signals from elements such as...
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 comparable with strongest detected at AD 774/775. The years stands out because its particular signature in radionuclide data [i.e., carbon-14 ( 14 C) alone does not allow for unequivocal detection event]. illustrates that present efforts to find events based solely on C likely lead underestimated number potentially devastating our society. In addition...