Oxygen isotope records of cores from the central Arctic Ocean yield evidence for a major influx of meltwater at the beginning of the last deglaciation 15.7 thousand years ago (16,650 calendar years B.C.). The almost parallel trends of the isotope records from the Arctic Ocean, the Fram Strait, and the east Greenland continental margin suggest contemporaneous variations of the Eurasian Arctic and Greenland (Laurentide) ice sheets or increased export of low-saline waters from the Arctic within the East Greenland Current during the last deglaciation. On the basis of isotope and carbon data, the modern surface- and deep-water characteristics and seasonally open-ice conditions with increased surface-water productivity were established in the central Arctic at the end of Termination lb about 7.2 thousand years ago or 6,000 calendar years B.C.).
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http://dx.doi.org/10.1126/science.264.5159.692 | DOI Listing |
Nat Commun
January 2025
Florida Museum of Natural History, Dickinson Hall, 1659 Museum Road, Gainesville, FL, 32611, USA.
The Thorny Skate (Amblyraja radiata) is a vulnerable species displaying a discrete size-polymorphism in the northwest Atlantic Ocean (NWA). We conducted whole genome sequencing of samples collected across its range. Genetic diversity was similar at all sampled sites, but we discovered a ~ 31 megabase bi-allelic supergene associated with the size polymorphism, with the larger size allele having introgressed in the last ~160,000 years B.
View Article and Find Full Text PDFCommun Earth Environ
January 2025
Recherche en Prévision Numérique Environnementale/Environnement et Changement Climatique Canada, Dorval, QC Canada.
The Last Ice Area-located to the north of Greenland and the northern Canadian Arctic Archipelago-is expected to persist as the central Arctic Ocean becomes seasonally ice-free within a few decades. Projections of the Last Ice Area, however, have come from relatively low resolution Global Climate Models that do not resolve sea ice export through the waterways of the Canadian Arctic Archipelago and Nares Strait. Here we revisit Last Ice Area projections using high-resolution numerical simulations from the Community Earth System Model, which resolves these narrow waterways.
View Article and Find Full Text PDFLife (Basel)
December 2024
N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk 163020, Russia.
Heart rate variability biofeedback (HRV BF) training aids adaptation to new climatic, geographical, and social environments. Neurophysiological changes during the HRV BF in individuals from tropical regions studying in the Arctic are not well understood. The aim of this study was to research electroencephalographic (EEG) changes during a single short-term HRV BF session in Indian and Russian students studying in the Russian Arctic.
View Article and Find Full Text PDFLancet Child Adolesc Health
February 2025
Stellenbosch University, Faculty of Medicine and Health Sciences, Department of Paediatrics and Child Health, Desmond Tutu TB Centre, Tygerberg, South Africa.
Background: There are few data on the treatment of children and adolescents with multidrug-resistant (MDR) or rifampicin-resistant (RR) tuberculosis, especially with more recently available drugs and regimens. We aimed to describe the clinical and treatment characteristics and their associations with treatment outcomes in this susceptible population.
Methods: We conducted a systematic review and individual participant data meta-analysis.
JAMA Psychiatry
January 2025
Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden.
Importance: Depressive symptoms are associated with cognitive decline in older individuals. Uncertainty about underlying mechanisms hampers diagnostic and therapeutic efforts. This large-scale study aimed to elucidate the association between depressive symptoms and amyloid pathology.
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