23 research outputs found
Effects of tectonic structures, salt solution mining, and density-driven groundwater hydraulics on evaporite dissolution (Switzerland)
Subsurface dissolution (subrosion) of evaporites such as halite and gypsum can lead to extensive land subsidence. Recent land subsidences have been surveyed at six separate locations in northwestern Switzerland. The diameters of the affected surface areas range from 100 to 1,500 m, and corresponding subsidence rates reached more than 100 mm/year. Based on a geometrical model, three sites could be outlined where land subsidence can likely be attributed to salt solution mining. The effects of increased hydrostatic gradient due to both groundwater withdrawal and fluid density contrasts were evaluated in more detail for the remaining sites with a series of 2D density-coupled solute-transport simulations along an approximately 1,000-m-long and 150-m-deep 2D cross section. Simulation results indicate that the upconing process of saline groundwater into the main aquifer occurs under different distributions of subsurface parameters and hydraulic boundary conditions. For the presented setup, the simulations also revealed that the most sensitive factor for the dissolution rate is the structure or dip of the halite formation, which leads to an increase of dissolution rate with increasing dip. Due to the increased density of the brine, an intrinsic flow dynamic develops which follows the direction of the di
Optimizing Carbon Storage Operations for Long-Term Safety
To combat global warming and mitigate the risks associated with climate
change, carbon capture and storage (CCS) has emerged as a crucial technology.
However, safely sequestering CO2 in geological formations for long-term storage
presents several challenges. In this study, we address these issues by modeling
the decision-making process for carbon storage operations as a partially
observable Markov decision process (POMDP). We solve the POMDP using belief
state planning to optimize injector and monitoring well locations, with the
goal of maximizing stored CO2 while maintaining safety. Empirical results in
simulation demonstrate that our approach is effective in ensuring safe
long-term carbon storage operations. We showcase the flexibility of our
approach by introducing three different monitoring strategies and examining
their impact on decision quality. Additionally, we introduce a neural network
surrogate model for the POMDP decision-making process to handle the complex
dynamics of the multi-phase flow. We also investigate the effects of different
fidelity levels of the surrogate model on decision qualities
Immune evasion by proteolytic shedding of natural killer group 2, member D ligands in Helicobacter pylori infection
BackgroundHelicobacter pylori (H. pylori) uses various strategies that attenuate mucosal immunity to ensure its persistence in the stomach. We recently found evidence that H. pylori might modulate the natural killer group 2, member 2 (NKG2D) system. The NKG2D receptor and its ligands are a major activation system of natural killer and cytotoxic T cells, which are important for mucosal immunity and tumor immunosurveillance. The NKG2D system allows recognition and elimination of infected and transformed cells, however viruses and cancers often subvert its activation. Here we aimed to identify a potential evasion of the NKG2D system in H. pylori infection.MethodsWe analyzed expression of NKG2D system genes in gastric tissues of H. pylori gastritis and gastric cancer patients, and performed cell-culture based infection experiments using H. pylori isogenic mutants and epithelial and NK cell lines.ResultsIn biopsies of H. pylori gastritis patients, NKG2D receptor expression was reduced while NKG2D ligands accumulated in the lamina propria, suggesting NKG2D evasion. In vitro, H. pylori induced the transcription and proteolytic shedding of NKG2D ligands in stomach epithelial cells, and these effects were associated with specific H. pylori virulence factors. The H. pylori-driven release of soluble NKG2D ligands reduced the immunogenic visibility of infected cells and attenuated the cytotoxic activity of effector immune cells, specifically the anti-tumor activity of NK cells.ConclusionH. pylori manipulates the NKG2D system. This so far unrecognized strategy of immune evasion by H. pylori could potentially facilitate chronic bacterial persistence and might also promote stomach cancer development by allowing transformed cells to escape immune recognition and grow unimpeded to overt malignancy
Immune evasion by proteolytic shedding of natural killer group 2, member D ligands in Helicobacter pylori infection
[Background]: Helicobacter pylori (H. pylori) uses various strategies that attenuate mucosal immunity to ensure its persistence in the stomach. We recently found evidence that H. pylori might modulate the natural killer group 2, member 2 (NKG2D) system. The NKG2D receptor and its ligands are a major activation system of natural killer and cytotoxic T cells, which are important for mucosal immunity and tumor immunosurveillance. The NKG2D system allows recognition and elimination of infected and transformed cells, however viruses and cancers often subvert its activation. Here we aimed to identify a potential evasion of the NKG2D system in H. pylori infection.[Methods]: We analyzed expression of NKG2D system genes in gastric tissues of H. pylori gastritis and gastric cancer patients, and performed cell-culture based infection experiments using H. pylori isogenic mutants and epithelial and NK cell lines.[Results]: In biopsies of H. pylori gastritis patients, NKG2D receptor expression was reduced while NKG2D ligands accumulated in the lamina propria, suggesting NKG2D evasion. In vitro, H. pylori induced the transcription and proteolytic shedding of NKG2D ligands in stomach epithelial cells, and these effects were associated with specific H. pylori virulence factors. The H. pylori-driven release of soluble NKG2D ligands reduced the immunogenic visibility of infected cells and attenuated the cytotoxic activity of effector immune cells, specifically the anti-tumor activity of NK cells.[Conclusion]: H. pylori manipulates the NKG2D system. This so far unrecognized strategy of immune evasion by H. pylori could potentially facilitate chronic bacterial persistence and might also promote stomach cancer development by allowing transformed cells to escape immune recognition and grow unimpeded to overt malignancy.Supported by the Austrian Science Fund (FWF, DK-MOLIN W1241 and the “Cluster of Excellence: Microbiomes Drive Planetary Health”) and by the Spanish Ministry of Science and Innovation under Grants (PID2021-123795OB-I00, PID2020-115506RB-I00) [Ministerio de Ciencia, Innovación y Universidades (MCIU)/Agencia Estatal de Investigación (AEI)/European Regional Development Fund (FEDER, EU)].Peer reviewe
Ein „heldenhafter“ Patient aus Bronze : Zur Restaurierung des Tegetthoff-Denkmals in Graz
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