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Ice core records of carbon dioxide (CO) throughout the last 2000 years provide context for the unprecedented anthropogenic rise in atmospheric CO and insights into global carbon cycle dynamics. Yet the atmospheric history of CO remains uncertain in some time intervals. Here we present measurements of CO and methane (CH) in the Skytrain ice core from 1450 to 1700 CE. Results suggest a sudden decrease in CO around 1610 CE in one widely used record may be an artefact of a small number of anomalously low values. Our analysis supports a more gradual decrease in CO of 0.5 ppm per decade from 1516 to 1670 CE, with an inferred land carbon sink of 2.6 PgC per decade. This corroborates modelled scenarios of large-scale reorganisation of land use in the Americas following New World-Old World contact, whereas a rapid decrease in CO at 1610 CE is incompatible with even the most extreme land-use change scenarios.
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http://dx.doi.org/10.1038/s41467-024-45894-9 | DOI Listing |
Alzheimers Dement
September 2025
Boston University Alzheimer's Disease Research Center and BU CTE Center, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts, USA.
We describe the rationale, methodology, and design of the Boston University Alzheimer's Disease Research Center (BU ADRC) Clinical Core (CC). The CC characterizes a longitudinal cohort of participants with/without brain trauma to characterize the clinical presentation, biomarker profiles, and risk factors of post-traumatic Alzheimer's disease (AD) and AD-related dementias (ADRD), including chronic traumatic encephalopathy (CTE). Participants complete assessments of traumatic brain injury (TBI) and repetitive head impacts (RHIs); annual Uniform Data Set (UDS) and supplementary evaluations; digital phenotyping; annual blood draw; magnetic resonance imaging (MRI) and lumbar puncture every 3 years; electroencephalogram (EEG); and amyloid and/or tau positron emission tomography (PET) on a subset.
View Article and Find Full Text PDFMedicine (Baltimore)
September 2025
School of Sports Science and Technology, Guangzhou College of Applied Science and Technology, Guangdong, China.
Objective: This study combines a bibliometric analysis with an umbrella review to delineate the research landscape, hotspots, and emerging trends in the application of artificial intelligence to the clinical diagnosis and treatment of mild cognitive impairment.
Methods: We searched the Web of Science Core Collection for literature published between 2004 and 2024. Bibliometric analysis of the retrieved publications was performed using CiteSpace and VOSviewer to map publication trends, international collaboration networks, key contributors, and keyword co-occurrence.
Small
August 2025
College of Chemical Engineering, State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
N-doped porous carbon materials are promising potassium-ion battery anodes for overcoming the depressing rate performance and poor cycling stability issues associated with the oversized radius of K-ion. However, the relatively low initial coulombic efficiency (ICE) as a result of porous structure and doped heteroatoms may limit the future application of potassium-ion batteries. Herein, a novel N-doped porous graphite-like carbon armored with dense amorphous shell is synthesized through a Trojan horse strategy by etching and doping the carbon matrix from inside out using oxidized coal tar pitch coated CN as precursor.
View Article and Find Full Text PDFISME J
August 2025
School of Oceanography & Astrobiology Program, University of Washington, Seattle, WA, USA.
Despite growing evidence for the role of DNA methylation in bacterial acclimation to environmental stress, this epigenetic mechanism remains unexplored in sea-ice microbial communities known to tolerate multiple stressors. This study presents a first analysis of DNA methylation patterns in bacterial communities and associated viruses across the vertical thickness of sea ice. Using a novel stepped-sackhole method, we collected sea-ice brines from distinct horizons of an Arctic ice floe, capturing microbial communities that had been exposed to different environmental conditions.
View Article and Find Full Text PDFCamb Prism Coast Futur
January 2025
Science Diplomacy Centerâ„¢, Falmouth, MA, USA.
The 5th International Polar Year (IPY-5) in 2032-2033 represents an important next step in the legacy of the oldest continuous climate research program created by humanity, which intentionally began during a Solar Maximum with IPY-1 in 1882-1883, following the Little Ice Age. Current IPY-5 planning by the International Arctic Science Committee (IASC) and Scientific Committee on Antarctic Research (SCAR) is "From IPY-4 to IPY-5" with scope since 2007-2008, considering relevant large-scale polar process, international activities and UN decades. Additionally, there are essential features to incorporate into IPY-5 planning with Indigenous knowledge as well as next-generation leadership along with international science connections across the United Nations, involving core integration of data system and Earth-Sun system research, which accelerated with the International Geophysical Year (IGY) in 1957-1958 that was renamed from IPY-3.
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