scholarly journals Supplementary material to "New ground ice maps for Canada using a paleogeographic modelling approach"

2018 ◽  
Author(s):  
H. Brendan O'Neill ◽  
Stephen A. Wolfe ◽  
Caroline Duchesne
Keyword(s):  
Ground Ice ◽  
Supplementary Material ◽  
Modelling Approach

scholarly journals New ground ice maps for Canada using a paleogeographic modelling approach

2019 ◽  
Vol 13 (3) ◽  
pp. 753-773 ◽  
Author(s):  
H. Brendan O'Neill ◽  
Stephen A. Wolfe ◽  
Caroline Duchesne
Keyword(s):  
Glacial Lake ◽  
Significant Advance ◽  
Small Scale ◽  
Permafrost Degradation ◽  
Field Observations ◽  
Tree Line ◽  
Ground Ice ◽  
Near Surface ◽  
Western Arctic ◽  
Modelling Approach

Abstract. Ground ice melt caused by climate-induced permafrost degradation may trigger significant ecological change, damage infrastructure, and alter biogeochemical cycles. The fundamental ground ice mapping for Canada is now >20 years old and does not include significant new insights gained from recent field- and remote-sensing-based studies. New modelling incorporating paleogeography is presented in this paper to depict the distribution of three ground ice types (relict ice, segregated ice, and wedge ice) in northern Canada. The modelling uses an expert-system approach in a geographic information system (GIS), founded in conceptual principles gained from empirically based research, to predict ground ice abundance in near-surface permafrost. Datasets of surficial geology, deglaciation, paleovegetation, glacial lake and marine limits, and modern permafrost distribution allow representations in the models of paleoclimatic shifts, tree line migration, marine and glacial lake inundation, and terrestrial emergence, and their effect on ground ice abundance. The model outputs are generally consistent with field observations, indicating abundant relict ice in the western Arctic, where it has remained preserved since deglaciation in thick glacigenic sediments in continuous permafrost. Segregated ice is widely distributed in fine-grained deposits, occurring in the highest abundance in glacial lake and marine sediments. The modelled abundance of wedge ice largely reflects the exposure time of terrain to low air temperatures in tundra environments following deglaciation or marine/glacial lake inundation and is thus highest in the western Arctic. Holocene environmental changes result in reduced ice abundance where the tree line advanced during warmer periods. Published observations of thaw slumps and massive ice exposures, segregated ice and associated landforms, and ice wedges allow a favourable preliminary assessment of the models, and the results are generally comparable with the previous ground ice mapping for Canada. However, the model outputs are more spatially explicit and better reflect observed ground ice conditions in many regions. Synthetic modelling products that incorporated the previous ground ice information may therefore include inaccuracies. The presented modelling approach is a significant advance in permafrost mapping, but additional field observations and volumetric ice estimates from more areas in Canada are required to improve calibration and validation of small-scale ground ice modelling. The ground ice maps from this paper are available in the supplement in GeoTIFF format.

scholarly journals Modelling platelet–blood flow interaction using the subcellular element Langevin method

2011 ◽  
Vol 8 (65) ◽  
pp. 1760-1771 ◽  
Author(s):  
Christopher R. Sweet ◽  
Santanu Chatterjee ◽  
Zhiliang Xu ◽  
Katharine Bisordi ◽  
Elliot D. Rosen ◽  
...  
Keyword(s):  
Blood Flow ◽  
Three Dimensional ◽  
Cell Interaction ◽  
Computationally Efficient ◽  
Cell Geometry ◽  
Linear Shear ◽  
Flow Interactions ◽  
Supplementary Material ◽  
Blood Chamber ◽  
Modelling Approach

In this paper, a new three-dimensional modelling approach is described for studying fluid–viscoelastic cell interaction, the subcellular element Langevin (SCEL) method, with cells modelled by subcellular elements (SCEs) and SCE cells coupled with fluid flow and substrate models by using the Langevin equation. It is demonstrated that: (i) the new method is computationally efficient, scaling as 𝒪( N ) for N SCEs; (ii) cell geometry, stiffness and adhesivity can be modelled by directly relating parameters to experimentally measured values; (iii) modelling the fluid–platelet interface as a surface leads to a very good correlation with experimentally observed platelet flow interactions. Using this method, the three-dimensional motion of a viscoelastic platelet in a shear blood flow was simulated and compared with experiments on tracking platelets in a blood chamber. It is shown that the complex platelet-flipping dynamics under linear shear flows can be accurately recovered with the SCEL model when compared with the experiments. All experimental details and electronic supplementary material are archived at http://biomath.math.nd.edu/scelsupplementaryinformation/.

scholarly journals Supplementary material to "Catchment tracers reveal discharge, recharge and sources of groundwater-borne pollutants in a novel lake modelling approach"

2017 ◽  
Author(s):  
Emil Kristensen ◽  
Mikkel Madsen-Østerbye ◽  
Philippe Massicotte ◽  
Ole Pedersen ◽  
Stiig Markager ◽  
...  
Keyword(s):  
Lake Modelling ◽  
Supplementary Material ◽  
Modelling Approach

scholarly journals Dataset-specific thresholds significantly improve detection of low transcribed regulatory genes in polysome profiling experiments

2020 ◽  
Author(s):  
Igor V. Deyneko ◽  
Orkhan N. Mustafaev ◽  
Alexander А. Tyurin ◽  
Ksenya V. Zhukova ◽  
Irina V. Goldenkova-Pavlova
Keyword(s):  
Great Influence ◽  
Background Level ◽  
Regulatory Proteins ◽  
Rna Seq ◽  
Biological Noise ◽  
Polysome Profiling ◽  
Higher Power ◽  
Genes Encoding ◽  
Supplementary Material ◽  
Modelling Approach

AbstractMotivationPolysome profiling is novel, and yet has proved to be an effective approach to detect mRNAs with differential ribosomal load and explore the regulatory mechanisms driving efficient translation. Genes encoding regulatory proteins, having a great influence of the organism, usually reveal moderate to low transcriptional levels, compared, for example, to genes of house-keeping machinery. This complicates the reliable detection of such genes in the presence of technical and/or biological noise.ResultsIn this work we investigate how cleaning of polysome profiling data on Arabidopsis thaliana influences the ability to detect genes with low level of total mRNA, but with a highly differential ribosomal load, i.e. genes translationally active. Suggested data modelling approach to identify a background level of mRNA counts individually for each dataset, shows higher power in detection of low transcribed genes, compared to the use of thresholds for the minimal required mRNA counts or the use of raw data. The significant increase in detected number of regulation–related genes was demonstrated. The described approach is applicable to a wide variety of RNA-seq data. All identified and classified mRNAs with high and low translation status are made available in supplementary material.

scholarly journals Supplementary material to "Impact of bottom trawling on sediment biogeochemistry: a modelling approach"

2020 ◽  
Author(s):  
Emil De Borger ◽  
Justin Tiano ◽  
Ulrike Braeckman ◽  
Adriaan D. Rijnsdorp ◽  
Karline Soetaert
Keyword(s):  
Bottom Trawling ◽  
Sediment Biogeochemistry ◽  
Supplementary Material ◽  
Modelling Approach

scholarly journals New ground ice maps for Canada using a paleogeographic modelling approach

2018 ◽  
Author(s):  
H. Brendan O'Neill ◽  
Stephen A. Wolfe ◽  
Caroline Duchesne
Keyword(s):  
Glacial Lake ◽  
Significant Advance ◽  
Small Scale ◽  
Permafrost Degradation ◽  
Field Observations ◽  
Tree Line ◽  
Ground Ice ◽  
Near Surface ◽  
Western Arctic ◽  
Modelling Approach

Abstract. Ground ice melt caused by climate-induced permafrost degradation may trigger significant ecological change, damage infrastructure, and alter biogeochemical cycles. The fundamental ground ice mapping for Canada is now > 20 years old, and does not include significant new insights gained from recent field and remote sensing based studies. New modelling incorporating paleogeography is presented in this paper to depict the distribution of three ground ice types (massive ice and icy sediments, segregated ice, and wedge ice) in northern Canada. The modelling uses an expert-system approach in a geographic information system (GIS), founded in conceptual principles gained from empirically-based research, to predict ground ice abundance in near-surface permafrost. Datasets of surficial geology, deglaciation, paleovegetation, glacial lake and marine limits, and modern permafrost distribution allow representations in the models of paleoclimatic shifts, tree line migration, marine and glacial lake inundation, and terrestrial emergence, and their effect on ground ice abundance. The model outputs are generally consistent with field observations, indicating abundant relict massive ice and icy sediments in the western Arctic, where it has remained preserved since deglaciation in thick glacigenic sediments in continuous permafrost. Segregated ice is widely distributed in fine-grained deposits, occurring in highest abundance in glacial lake and marine sediments. The modelled abundance of wedge ice largely reflects the exposure time of terrain to low air temperatures in tundra environments following deglaciation or marine/glacial lake inundation, and is thus highest in the western Arctic. Holocene environmental changes result in reduced ice abundance where tree line advanced during warmer periods. Published observations of thaw slumps and ice exposures, segregated ice and associated landforms, and ice wedges allow a favourable preliminary assessment of the models, and the results are generally comparable with the previous ground ice mapping for Canada. However, the model outputs are more spatially explicit and better reflect observed ground ice conditions in some regions. Synthetic modelling products that incorporated the previous ground ice information may therefore include inaccuracies. The presented modelling approach is a significant advance in permafrost mapping, but additional field observations and volumetric ice estimates from more areas in Canada are required to improve calibration and validation of small-scale ground ice modelling.

Sign in / Sign up

Export Citation Format

Share Document