Article
Geochemistry & Geophysics
Alexandra Fogtmann-Schulz, Claudia Baittinger, Christoffer Karoff, Jesper Olsen, Mads F. Knudsen
Summary: A new biennial record of radiocarbon measured in Danish oak covering the years 1251-1378 CE shows changes in the Hale and Schwabe solar cycles during the Wolf Minimum. The record's spectral analysis revealed peaks at 27 and 9.1 years, suggesting alterations in these cycles, but further research is needed to confirm these findings. The study also reconstructed the solar modulation function indicating a periodicity of approximately 9 years preceding the Wolf Minimum.
Article
Astronomy & Astrophysics
Shuai Fu, Xiaoping Zhang, Lingling Zhao, Yong Li
Summary: This paper investigates Galactic cosmic-ray variations over solar cycles 23 and 24, revealing record-breaking GCR intensities during the solar minimum in 2019-2020 and changes in the modulation environment that reduce solar modulation levels, providing a plausible explanation for the intense GCR levels in interplanetary space.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2021)
Article
Soil Science
Katherine A. Heckman, Christopher W. Swanston, Margaret S. Torn, Paul J. Hanson, Lucas E. Nave, Rachel C. Porras, Umakant Mishra, Markus Bill
Summary: The sources and stability of soil organic carbon are still poorly understood, with the complexity of the soil C cycle system hindering a clear understanding of its components. Experimental results from Oak Ridge Reservation indicate that newly fixed plant carbon can rapidly incorporate into all fractions of soil, regardless of their previous stability, suggesting a high degree of heterogeneity within soil fractions.
Article
Engineering, Aerospace
Dieter Bilitza, Chao Xiong
Summary: The study utilized various satellite and sounder data to refine the IRI model for a more accurate representation of the topside ionosphere's response to solar activity, with good agreement between different data sets.
ADVANCES IN SPACE RESEARCH
(2021)
Article
Geosciences, Multidisciplinary
Weiyi Sun, Jian Liu, Bin Wang, Deliang Chen, Lingfeng Wan, Jing Wang
Summary: This study investigates the influence of solar activity on the Asian summer monsoon (ASM) at different time scales. Simulation results suggest that solar forcing can significantly affect ASM precipitation on a 300-600-year periodicity during the middle-late Holocene. Proxy data also support this multi-centennial variation. The western North Pacific circulation system plays a key role in modulating the ASM variation, through enhancing the south Asia-WNP monsoon trough.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Astronomy & Astrophysics
Leonid Kitchatinov, Anna Khlystova
Summary: This study proposes a dynamo model to explain the phenomenon of long-term north-south asymmetry in sunspot activity, showing how the superposition of dipolar and quadrupolar fields leads to this asymmetry. The model computations reveal the phase-locking and irregular transitions of dipolar and quadrupolar fields oscillations. Additionally, the possibility of polar field asymmetry as a precursor of sunspot asymmetry in following activity cycles is discussed based on the dynamo model and observations.
ASTROPHYSICAL JOURNAL
(2021)
Article
Energy & Fuels
Ramesh Pandey, Amit Munshi, Tushar Shimpi, Akash Shah, Alexandra Bothwell, Darius Kuciauskas, James R. Sites
Summary: By adjusting the magnesium content in the MgXZn1-XO (MZO) emitter, the optimal efficiency for CdTe-based solar cells can be achieved, with good cell performance seen in a range of x values from 0.1 to 0.25.
Article
Astronomy & Astrophysics
Geisa Ponte, Diego Lorenzo-Oliveira, Jorge Melendez, Jhon Yana Galarza, Adriana Valio
Summary: The study finds that the photometric variability of solar-twins is strongly correlated with stellar age, and can be used as a simple age diagnostic.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Oncology
Heidi Amalie Rosendahl Jensen, Trine Allerslev Horsbol, Lau Caspar Thygesen, Michael Davidsen, Anne Illemann Christensen, Ola Ekholm
Summary: This study examines the accuracy of self-reported cancer history and its negative predictive value using registry data as the criterion standard. The results show that the negative predictive value is consistently high, but sensitivity varies greatly across different cancer types.
INTERNATIONAL JOURNAL OF CANCER
(2023)
Article
Biotechnology & Applied Microbiology
Yu-He Zhao, Tong Zhou, Jiu-Xia Wang, Yan Li, Min-Feng Fang, Jian-Ni Liu, Zhong-Hu Li
Summary: This study investigated the nucleotide evolution, phylogenetic relationships, and structural variations of chloroplast tRNAs in gymnosperms, revealing conserved secondary structures, presence of precoded 3' CCA tails, and novel structural changes affecting tRNA stability. Phylogenetic analysis indicated tRNAs evolved from multiple common ancestors, with a higher transition rate compared to the transversion rate, and more loss events than duplication events in gymnosperm chloroplast tRNAs.
Article
Environmental Sciences
Rui Cheng, Troy S. Magney, Erica L. Orcutt, Zoe Pierrat, Philipp Kohler, David R. Bowling, M. Syndonia Bret-Harte, Eugenie S. Euskirchen, Martin Jung, Hideki Kobayashi, Adrian Rocha, Oliver Sonnentag, Jochen Stutz, Sophia Walther, Donatella Zona, Christian Frankenberg
Summary: Photosynthesis of terrestrial ecosystems in the Arctic-Boreal region is crucial for the global carbon cycle. However, using solar-induced chlorophyll fluorescence (SIF) as a proxy for photosynthesis in high latitudes presents challenges due to unique plant species and land cover types, as well as complex terrain and sub-pixel land cover. This study evaluates the empirical relationships between SIF and gross primary production (GPP) in the Arctic-Boreal region, revealing specific issues that need to be considered for accurate estimation of GPP and dealing with model-data uncertainties.
ENVIRONMENTAL RESEARCH LETTERS
(2022)
Article
Astronomy & Astrophysics
Valeriy Tenishev, Michael R. Combi, Yinsi Shou, Stephen Bougher, Yingjuan Ma
Summary: Due to the lack of a substantial planetary magnetic field, the fast-flowing solar wind plasma can spread to regions close to Venus, resulting in the interaction between Venus and the plasma. The distribution of thermal atomic oxygen in the thermosphere and corona is crucial in understanding this interaction. By combining the Venus Thermosphere General Circulation Model (VTGCM) and Adaptive Mesh Particle Simulator (AMPS) codes, we have successfully studied the variability of the hot oxygen corona under different solar conditions.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Forestry
Sofia Knapic, Camila S. F. Linhares, Jose S. Machado
Summary: This study analyzed the within-stem variation in the mechanical properties of Portuguese oak wood. The results showed that the distance to pith had a significant effect on the mechanical properties for one provenance, but not for others.
Review
Astronomy & Astrophysics
Bidya Binay Karak
Summary: One obvious feature of the solar cycle is its variation from one cycle to another. This article reviews the dynamo models for the long-term variations of the solar cycle, including modulations beyond the 11-year periodicity. The article discusses the causes for the modulation, presents illustrative models, and highlights the current trends and challenges.
LIVING REVIEWS IN SOLAR PHYSICS
(2023)
Article
Geochemistry & Geophysics
Alison K. Tune, Jennifer L. Druhan, Corey R. Lawrence, Daniella M. Rempe
Summary: This study investigates the oxidation of organic carbon in sedimentary bedrock and finds that the actual oxidation rate in the field is much lower than the rate achieved in laboratory experiments. Physical accessibility of organic carbon is found to be a key factor influencing oxidation, and respiration of recently fixed carbon from deep rooting dominates CO2 production.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Architecture
Giulia Tirelli, Giovanna Bosi, Anna Galli, Irka Hajdas, Alf Lindroos, Marco Martini, Francesco Maspero, Marta Mazzanti, Jesper Olsen, Laura Panzeri, Asa Ringbom, Emanuela Sibilia, Elena Silvestri, Paola Torri, Stefano Lugli
Summary: This study examines the vaults of the medieval Modena Cathedral in the 15th century, revealing the presence of different materials and multiple repair works over time. The findings provide valuable insights into the construction history and earthquake chronology of the cathedral, which are crucial for earthquake risk assessments and strengthening projects of ancient buildings.
INTERNATIONAL JOURNAL OF ARCHITECTURAL HERITAGE
(2023)
Review
Plant Sciences
Welmoed A. Out, Kirsti Hanninen, Claudia Baittinger, Caroline Vermeeren
Summary: This paper explores the hypothesis of woodland management at the Neolithic Alvastra site by reviewing previous arguments and interpretations. The results indicate that there is no evidence supporting the practice of woodland management at this site.
VEGETATION HISTORY AND ARCHAEOBOTANY
(2022)
Article
Astronomy & Astrophysics
Hong-peng Lu, Hui Tian, Li-yun Zhang, Christoffer Karoff, He-chao Chen, Jian-rong Shi, Zhen-yong Hou, Ya-jie Chen, Yu Xu, Yu-chuan Wu, Dong-tao Cao, Jiang-tao Wang
Summary: This study successfully detected three stellar CME candidates by analyzing the asymmetries of H alpha line profiles and found that the H alpha lines of these candidates exhibit blue-wing or red-wing enhancements. This indicates the existence of stellar CMEs in main-sequence stars.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Anthropology
Mark Horton, Jesper Olsen, Jeffrey Fleisher, Stephanie Wynne-Jones
Summary: In this article, the authors present the results of a recent high-resolution radiocarbon dating program on the urban sequence at Kilwa Kisiwani in southern Tanzania. The study includes Bayesian modeling of 21 calibrated C-14 dates and offers new insights into the timing and tempo of the occupation at Kilwa.
AFRICAN ARCHAEOLOGICAL REVIEW
(2022)
Article
Environmental Sciences
Nicolaj K. Larsen, Anne Sofie Sondergaard, Laura B. Levy, Astrid Strunk, Daniel S. Skov, Anders Bjork, Shfaqat A. Khan, Jesper Olsen
Summary: Northeast Greenland has experienced significant changes in the Greenland Ice Sheet, and this study provides new age constraints for the deglaciation process. By analyzing cosmogenic exposure ages, the authors determine that the outer coast region deglaciated between 12.8 +/- 0.6 and 11.5 +/- 0.2 ka, while the region close to the present ice margin deglaciated 2 to 4 ka later between 9.2 +/- 0.3 to 8.6 +/- 0.3 ka. These findings contribute to our understanding of the glaciation history of the Greenland Ice Sheet and can be useful for future ice sheet models.
ARCTIC ANTARCTIC AND ALPINE RESEARCH
(2022)
Article
Geography, Physical
Sabrina Gjodvad Kaiser Kudsk, Mads Faurschou Knudsen, Christoffer Karoff, Claudia Baittinger, Stergios Misios, Jesper Olsen
Summary: This study investigates solar variability between 650 CE and 1900 based on new and published C-14 records. It identifies a Maunder-type minimum in 656-707 CE and suggests a potential prolongation of the 11-year solar cycle before the onset of major solar minima. The study also reviews the impact of near-Earth supernova events on C-14 production rates.
QUATERNARY SCIENCE REVIEWS
(2022)
Article
Anthropology
Tibor-Tamas Daroczi, Marietta Csanyi, Judit Tarnoki, Fanni Nagy, Jesper Olsen
Summary: The multi-stratified site of Turkeve-Terehalom provides valuable insights into the Middle Bronze Age in the Eastern Carpathian Basin. Through meticulous excavation and linking of stratified finds, particularly pottery, a new chronological model has been established. This challenges existing views on Bronze Age structures, destruction patterns, and continental networking during the Middle Bronze Age.
PRAEHISTORISCHE ZEITSCHRIFT
(2023)
Article
Archaeology
Jacob Kveiborg, Jesper Olsen
Summary: This study applies targeted radiocarbon dating to investigate animal bone depositions in Danish wetland sites during the early Iron Age. The results reveal a highly complex biography of ritual wetland deposits, lasting up to 800 years from the 4th - 5th century BC. Domestic animal species were preferred, suggesting their special significance. Some species were deposited for longer periods, and certain wetland sites were used for centuries while others were not. Overall, the study highlights the intricate and dynamic relationship between wetlands, animals, and early Iron Age rituals.
JOURNAL OF ARCHAEOLOGICAL SCIENCE-REPORTS
(2023)
Article
Orthopedics
Allan Cramer, Grith Hojfeldt, Peter Schjerling, Jakob Agergaard, Gerrit van Hall, Jesper Olsen, Per Holmich, Michael Kjaer, Kristoffer Weisskirchner Barfod
Summary: The study aimed to investigate the turnover of tendon tissue before and after an Achilles tendon rupture. The results showed that there was already increased turnover of tendon tissue before the rupture, and the synthesis rate of collagen remained relatively constant in the first two weeks after the rupture. This suggests that the formation of new tendon tissue is not an immediate process during the regeneration of ruptured tendons in patients.
AMERICAN JOURNAL OF SPORTS MEDICINE
(2023)
Article
Geosciences, Multidisciplinary
Jesper Norgaard, Martin Margold, John D. Jansen, Redzhep Kurbanov, Izabela Szuman, Jane Lund Andersen, Jesper Olsen, Mads Faurschou Knudsen
Summary: This study presents the first dates from the central part of Northeast Siberia, providing age constraints on glaciations in the region. The results indicate limited Late Pleistocene glaciations to the highlands, suggesting the absence of a large, coalescent ice sheet in Northeast Siberia during the Last Glacial Maximum or Marine Isotope Stage 6.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Archaeology
Gerard T. Barrett, Kerry Allen, Paula J. Reimer, Asa Ringbom, Jesper Olsen, Alf Lindroos
Summary: Ramped pyrolysis radiocarbon dating was performed on lime lumps extracted from the oldest remains of Turku Cathedral in Finland. The results revealed an age range in the late 13th century AD, which aligns with historical sources and previous dating work. This study demonstrates the reliability and repeatability of ramped pyrolysis as a technique for dating mortar.
JOURNAL OF CULTURAL HERITAGE
(2023)
Article
Geochemistry & Geophysics
Jesper Olsen, Tibor-Tamas Daroczi, Marie Kanstrup
Summary: During the past twenty years, radiocarbon dating of hydroxyapatite archaeological cremated bones has become a standard practice. Different laboratories have various pretreatment procedures, some of which involve the use of Sulfix to fix SO2 prior to CO2 reduction. Recent findings suggest that the use of Sulfix may lead to older C-14 ages. This study reports on the use of Sulfix at the Aarhus AMS Centre and presents an experiment testing alternative purification agents.
Article
Geosciences, Multidisciplinary
Christoffer Karoff, Angel Liduvino Vara-Vela
Summary: Over the past decade, there has been a significant and unexplained increase in methane emissions, which could contribute to accelerated climate change. The primary source of this increase is believed to be agriculture, although oil and gas production as well as wetlands are also potential contributors. To accurately measure methane emissions, space-based remote sensing is the most effective method. Through the analysis of three years of data, it was discovered that methane concentrations are highest over croplands and lowest over shrublands, consistent with expectations. However, it was surprising to find lower than average methane concentrations over wetlands, which are typically considered a major source of methane emissions.
FRONTIERS IN EARTH SCIENCE
(2023)
