Southeast Greenland contributes significantly to global sea level rise, with mass loss having increased by about 600% over the past 30 years due to enhanced melt and dynamic instabilities of marine-terminating glaciers. Accurate modelling of glacier dynamics is crucial to minimise uncertainties in predictions of future sea level rise, necessitating detailed reconstructions of long-term glacial histories. One key complexity in these models that is not well understood or documented is ice flow piracy, where ice is redirected between catchment basins, significantly influencing regional glacier dynamics and mass balance.
View Article and Find Full Text PDFThis paper introduces a comprehensive protocol leveraging open-access techniques to create small- to medium-scale 3D representations of the environment by using iPhone and iPad light detection and ranging (LiDAR). The protocol focuses on two capabilities of the iPhone LiDAR. The first capability is 3D modeling: iPhone LiDAR rapidly generates detailed indoor and outdoor 3D models, providing insights into object size, volume and geometry.
View Article and Find Full Text PDFThe major input of mercury (Hg) to the Arctic is normally ascribed to long-range transport of anthropogenic Hg emissions. Recently, alarming concentrations of Hg in meltwater from the Greenland Ice Sheet (GrIS) were reported with bedrock as the proposed source. Reported Hg concentrations were 100 to 1000 times higher than in known freshwater systems of Greenland, calling for independent validation of the extraordinary concentrations and conclusions.
View Article and Find Full Text PDFMicroorganisms in subsurface sediments live from recalcitrant organic matter deposited thousands or millions of years ago. Their catabolic activities are low, but the deep biosphere is of global importance due to its volume. The stability of deeply buried sediments provides a natural laboratory where prokaryotic communities that live in steady state with their environments can be studied over long time scales.
View Article and Find Full Text PDFIn the ongoing debates about eukaryogenesis-the series of evolutionary events leading to the emergence of the eukaryotic cell from prokaryotic ancestors-members of the Asgard archaea play a key part as the closest archaeal relatives of eukaryotes. However, the nature and phylogenetic identity of the last common ancestor of Asgard archaea and eukaryotes remain unresolved. Here we analyse distinct phylogenetic marker datasets of an expanded genomic sampling of Asgard archaea and evaluate competing evolutionary scenarios using state-of-the-art phylogenomic approaches.
View Article and Find Full Text PDFWe used ancient DNA (aDNA) extraction methods to sequence museum voucher samples of a frenulate siboglinid polychaete described from a northern Norwegian fjord over fifty years ago. Our sequencing results indicate a genetic match with the cryptic seep species, (99% pairwise identity for 574 bp mtCOI fragments) Due to its similarity with , the identity of has been a matter of debate since its description, which we have now resolved. Furthermore, our results demonstrate that chemosynthesis-based siboglinids, that constitute the bulk of the biomass at Arctic seeps are not seep specialists.
View Article and Find Full Text PDFLate Pliocene and Early Pleistocene epochs 3.6 to 0.8 million years ago had climates resembling those forecasted under future warming.
View Article and Find Full Text PDFPurpose: To investigate whether skiers with a fast-start pacing pattern increase time-trial performance by use of a more even pacing strategy.
Methods: Thirty-four skiers (∼17 y, 16 male) performed an individual 7.5 (3 × 2.
Population ageing has resulted in an increasing number of older people living with chronic diseases (multimorbidity) requiring five or more medications daily (polypharmacy). Ageing produces important changes in the cardiovascular system and represents the most potent single cardiovascular risk factor. Cardiovascular diseases (CVDs) constitute the greatest burden for older people, their caregivers, and healthcare systems.
View Article and Find Full Text PDFPurpose: The cardiac T-wave peak-to-end interval (T) is thought to reflect dispersion in ventricular repolarisation, with abnormalities in T associated with increased risk of arrhythmia. Extracellular K modulates cardiac repolarisation, and since arterial plasma K concentration ([K]) rapidly increases during and declines following exercise, we investigated the relationship between [K] and T with exercise.
Methods: Serial ECGs (T, T/QT ratio) and [K] were obtained from 8 healthy, normokalaemic volunteers and 22 patients with end-stage renal disease (ESRD), at rest, during, and after exhaustive exercise.
During the last glacial-interglacial cycle, Arctic biotas experienced substantial climatic changes, yet the nature, extent and rate of their responses are not fully understood. Here we report a large-scale environmental DNA metagenomic study of ancient plant and mammal communities, analysing 535 permafrost and lake sediment samples from across the Arctic spanning the past 50,000 years. Furthermore, we present 1,541 contemporary plant genome assemblies that were generated as reference sequences.
View Article and Find Full Text PDFThe origin of the eukaryotic cell is a major open question in biology. Asgard archaea are the closest known prokaryotic relatives of eukaryotes, and their genomes encode various eukaryotic signature proteins, indicating some elements of cellular complexity prior to the emergence of the first eukaryotic cell. Yet, microscopic evidence to demonstrate the cellular structure of uncultivated Asgard archaea in the environment is thus far lacking.
View Article and Find Full Text PDFPharmacogenomics promises to advance cardiovascular therapy, but there remain pragmatic barriers to implementation. These are particularly important to explore within Europe, as there are differences in the populations, availability of resources, and expertise, as well as in ethico-legal frameworks. Differences in healthcare delivery across Europe present a challenge, but also opportunities to collaborate on pharmacogenomics implementation.
View Article and Find Full Text PDFOil spills in Arctic marine environments are expected to increase concurrently with the expansion of shipping routes and petroleum exploitation into previously inaccessible ice-dominated regions. Most research on oil biodegradation focusses on the bulk oil, but the fate of the water-accommodated fraction (WAF), mainly composed of toxic aromatic compounds, is largely underexplored. To evaluate the bacterial degradation capacity of such dissolved aromatics in Greenlandic seawater, microcosms consisting of 0 °C seawater polluted with WAF were investigated over a 3-month period.
View Article and Find Full Text PDFSulfate-reducing microorganisms (SRM) in subsurface sediments live under constant substrate and energy limitation, yet little is known about how they adapt to this mode of life. We combined controlled chemostat cultivation and transcriptomics to examine how the marine sulfate reducer, Desulfobacterium autotrophicum, copes with substrate (sulfate or lactate) limitation. The half-saturation uptake constant (K) for lactate was 1.
View Article and Find Full Text PDFThe Greenland ice sheet has been one of the largest sources of sea-level rise since the early 2000s. However, basal melt has not been included explicitly in assessments of ice-sheet mass loss so far. Here, we present the first estimate of the total and regional basal melt produced by the ice sheet and the recent change in basal melt through time.
View Article and Find Full Text PDFHypokalaemia is common in patients with cardiovascular disease. In this review, we emphasize the importance of tight potassium regulation in patients with cardiovascular disease based on findings from observational studies. To enhance the understanding, we also describe the mechanisms of potassium homeostasis maintenance, the most common causes of hypokalaemia and present strategies for monitoring and management of low potassium levels.
View Article and Find Full Text PDFA previous cultivation-independent investigation of the microbial community structure of natural oil and asphalt seeps in the Kurdistan Region of Iraq (KRI) revealed the dominance of uncultured bacterial taxa belonging to the phyla Deferribacterota and Coprothermobacterota and the orders Thermodesulfobacteriales, Thermales, and Burkholderiales. Here we report on a cultivation-dependent approach to identify members of these groups involved in hydrocarbon degradation in the KRI oil and asphalt seeps. For this purpose, we set up anoxic crude oil-degrading enrichment cultures based on cultivation media known to support the growth of members of the above-mentioned taxonomic groups.
View Article and Find Full Text PDF