| 1. |
- Yang, D. P., et al.
(författare)
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Nociceptor neurons direct goblet cells via a CGRP-RAMP1 axis to drive mucus production and gut barrier protection
- 2022
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Ingår i: Cell. - : Elsevier BV. - 0092-8674. ; 185:22
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Tidskriftsartikel (refereegranskat)abstract
- Neuroepithelial crosstalk is critical for gut physiology. However, the mechanisms by which sensory neurons communicate with epithelial cells to mediate gut barrier protection at homeostasis and during inflammation are not well understood. Here, we find that Nav1.8+CGRP+ nociceptor neurons are juxtaposed with and signal to intestinal goblet cells to drive mucus secretion and gut protection. Nociceptor ablation led to decreased mucus thickness and dysbiosis, while chemogenetic nociceptor activation or capsaicin treatment induced mucus growth. Mouse and human goblet cells expressed Ramp1, receptor for the neuropeptide CGRP. Nociceptors signal via the CGRP-Ramp1 pathway to induce rapid goblet cell emptying and mucus secretion. Notably, commensal microbes activated nociceptors to control homeostatic CGRP release. In the absence of nociceptors or epithelial Ramp1, mice showed increased epithelial stress and susceptibility to colitis. Conversely, CGRP administration protected nociceptor-ablated mice against colitis. Our findings demon-strate a neuron-goblet cell axis that orchestrates gut mucosal barrier protection.
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| 2. |
- Baeumer, B., et al.
(författare)
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Boundary conditions for fractional diffusion
- 2018
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Ingår i: Journal of Computational and Applied Mathematics. - : Elsevier BV. - 0377-0427. ; 336, s. 408-424
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Tidskriftsartikel (refereegranskat)abstract
- This paper derives physically meaningful boundary conditions for fractional diffusion equations, using a mass balance approach. Numerical solutions are presented, and theoretical properties are reviewed, including well-posedness and steady state solutions. Absorbing and reflecting boundary conditions are considered, and illustrated through several examples. Reflecting boundary conditions involve fractional derivatives. The Caputo fractional derivative is shown to be unsuitable for modeling fractional diffusion, since the resulting boundary value problem is not positivitypreserving.
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| 3. |
- Baeumer, Boris, et al.
(författare)
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Reprint of: Boundary conditions for fractional diffusion
- 2018
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Ingår i: Journal of Computational and Applied Mathematics. - : Elsevier BV. - 0377-0427. ; 339, s. 414-430
-
Tidskriftsartikel (refereegranskat)abstract
- This paper derives physically meaningful boundary conditions for fractional diffusion equations, using a mass balance approach. Numerical solutions are presented, and theoretical properties are reviewed, including well-posedness and steady state solutions. Absorbing and reflecting boundary conditions are considered, and illustrated through several examples. Reflecting boundary conditions involve fractional derivatives. The Caputo fractional derivative is shown to be unsuitable for modeling fractional diffusion, since the resulting boundary value problem is not positivity preserving.
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| 4. |
- Gustafson, Gunnar, 1945, et al.
(författare)
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A new stochastic model for fracture transmissivity assessment
- 2008
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Ingår i: Water Resources Research. - 0043-1397 .- 1944-7973. ; 44
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Tidskriftsartikel (refereegranskat)abstract
- A new stochastic model is proposed for fracture counts and transmissivities in a borehole interval. This new model incorporates several empirical observations, including: (i) Clustering of fractures; (ii) Exponential fracture spacings; (iii) Transmissivities extending over several orders of magnitude; (iv) Power law probability tail for transmissivities at finer scales; (v) Log-normal transmissivities at larger scales; and (vi) Dependence between fracture counts and transmissivities. Several example applications are provided using borehole data from Sweden
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