In this study, six bacterial community structures were analyzed from the Dunde ice core (9.5-m-long) using 16S rRNA gene cloning library technology. Compared to the Muztagata mountain ice core (37-m-long), the Dunde ice core has different dominant community structures, with five genus-related groups sp./, -related., sp., sp., and sp. that are frequently found in the six tested ice layers from 1990 to 2000. Live and total microbial density patterns were examined and related to the dynamics of physical-chemical parameters, mineral particle concentrations, and stable isotopic ratios in the precipitations collected from both Muztagata and Dunde ice cores. The Muztagata ice core revealed seasonal response patterns for both live and total cell density, with high cell density occurring in the warming spring and summer months indicated by the proxy value of the stable isotopic ratios. Seasonal analysis of live cell density for the Dunde ice core was not successful due to the limitations of sampling resolution. Both ice cores showed that the cell density peaks were frequently associated with high concentrations of particles. A comparison of microbial communities in the Dunde and Muztagata glaciers showed that similar taxonomic members exist in the related ice cores, but the composition of the prevalent genus-related groups is largely different between the two geographically different glaciers. This indicates that the micro-biogeography associated with geographic differences was mainly influenced by a few dominant taxonomic groups.
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http://dx.doi.org/10.3389/fmicb.2016.01716 | DOI Listing |
Environ Sci Technol
December 2024
Climate and Environmental Physics, Physics Institute, and Oeschger Centre for Climate Change Research, University of Bern, Sidlerstrasse 5, Bern 3012, Switzerland.
This study presents the integration of the single-particle extinction and scattering (SPES) method in a continuous flow analysis (CFA) setup. Continuous measurements with the instrument allow for the characterization of water-insoluble particles in ice cores at high resolution with a minimized risk of contamination. The SPES method can be used to investigate particles smaller than 1 μm, which previously could not be detected by instruments typically used in CFA.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
Department of Aerospace Engineering, Iowa State University, Ames, Iowa 50014, United States.
Using an interatomic potential that can capture the tetrahedral configuration of water molecules (HO) in ice without the need to explicitly track the motion of the O and H atoms, coarse-grained (CG) atomistic simulations are performed here to characterize the structures, energy, cohesive strengths, and fracture resistance of the grain boundaries (GBs) in polycrystalline ice resulting from water freezing. Taking the symmetric tilt grain boundaries (STGBs) with a tilting axis of ⟨0001⟩ as an example, several main findings from our simulations are (i) the GB energy, , exhibits a strong dependence on the GB misorientation angle, θ. The classical Read-Shockley model only predicts the - θ relation reasonably well when θ < 20° or θ > 45° but fails when 20° < θ < 45°; (ii) two "valleys" appear in the -θ landscape.
View Article and Find Full Text PDFCrit Care
December 2024
Department of Intensive Care, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium.
Background: Intracranial multimodal monitoring (iMMM) is increasingly used in neurocritical care, but a lack of standardization hinders its evidence-based development. Here, we devised core outcome sets (COS) and reporting guidelines to harmonize iMMM practices and research.
Methods: An open, decentralized, three-round Delphi consensus study involved experts between December 2023 and June 2024.
An Acad Bras Cienc
December 2024
Universidade Federal do Rio Grande do Sul, Centro Polar e Climático, Av. Bento Gonçalves, 9500, 91501-970 Porto Alegre, RS, Brazil.
This study investigated the chemical content of a shallow snow core (4.95 m) named TT 6, collected during a Brazilian traverse of the West Antarctic Ice Sheet in the 2014/2015 Austral summer. Stable isotope ratios (δD and δ18O) and ionic content, determined at the Centro Polar e Climático of the Federal University of Rio Grande do Sul (CPC/UFRGS), were used to date the core and reconstruct the climatic conditions at the site.
View Article and Find Full Text PDFAustralas Emerg Care
December 2024
Ambulance Victoria, Doncaster, Victoria, Australia; Monash University, Department of Paramedicine, Frankston, Victoria, Australia; Monash University, School of Public Health and Preventive Medicine, Melbourne, Victoria, Australia. Electronic address:
Introduction: Hypothermia can increase mortality in certain patients. Paramedics apply cotton and foil "space" blankets for warming, yet their effectiveness remains uncertain. This pilot study aimed to evaluate combining cotton blankets with a self-warming blanket versus a combination of cotton blankets and a foil blanket in an out-of-hospital simulation.
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