| 1. |
- Hartung, Kerstin, 1989-
(författare)
-
Paths to improving atmospheric models across scales : The importance of the unresolved scales
- 2018
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Correct representation of physical processes, the parametrizations, and their interaction with the resolved circulation is crucial for the performance of numerical models. Here, focus is put on understanding model biases and developing tools to alleviate existing biases. Atmospheric blocking can divert the typical atmospheric flow for several days up to weeks and thereby impacts the mean climate of the region experiencing blocking. Models typically underestimate the frequency of atmospheric blocking. Based on results from the global climate model EC-Earth, it is found that the atmospheric model resolution is not strongly influencing the representation of atmospheric blocking once the grid reaches about 80 km grid length in the horizontal. Updating several physical parametrizations, and thereby the model version, is the largest contributor to advancements in simulating atmospheric blocking. The importance of the topography for the large-scale atmospheric flow is further investigated with the reanalysis ERA-Interim by applying a simplified theoretical analysis. It is found that the idealized topographic forcing theory can explain some part of the observed large-scale properties of the flow, though the method does mainly produce relative results. The explained part of the large-scale structure is increased during periods of northwesterly flow and when the flow impinges the mountain ridge almost orthogonally.Small-scale processes acting in air masses transported from midlatitudes to the Arctic are also discussed. Numerical models often struggle with representing the stable conditions in the Arctic and tend to underestimate the downward longwave impact during cloudy conditions. A comparison of single-column models (SCMs) indicates that most models can capture the bimodal longwave distribution which develops from alternating cloudy and clear-sky conditions. SCMs are often used for model development as they allow to decouple the parametrized physical processes from the large-scale environment and enable many parameter sensitivity tests. A new tool is presented which can be used for the development of physical parametrizations in marine and polar conditions. It combines one-dimensional models of the atmosphere and ocean, including sea-ice, into a coupled atmosphere-ocean SCM (AOSCM). The presented setup constitutes an advantage compared to SCMs of one component because the coupling is directly modelled and the interaction between the respective boundary layers does not dependent on prescribed boundary conditions.
|
|
| 2. |
- Ren, Yansong, et al.
(författare)
-
Multistimuli-Responsive Enaminitrile Molecular Switches Displaying H+-Induced Aggregate Emission, Metal Ion-Induced Turn-On Fluorescence, and Organogelation Properties
- 2018
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 140:42, s. 13640-13643
-
Tidskriftsartikel (refereegranskat)abstract
- Multistimuli-responsive enaminitrile-based configurational switches displaying aggregation-induced emission (AIE), fluorescence turn-on effects, and super gelation properties are presented. The E-isomers dominated (>97%) in neutral/basic solution, and the structures underwent precisely controlled switching around the enamine C=C bond upon addition of acid/base. Specific fluorescence output was observed in response to different external input in the solution and solid states. In response to H+, configurational switching resulted in complete formation of the nonemissive Z-H+-isomers in solution, however displaying deep-blue to blue fluorescence (Phi(F) up to 0.41) in the solid state. In response to Cu-II in the solution state, the E-isomers exhibited intense, turn-on, blue-green fluorescence, which could be turned off by addition of competitive coordination. The acid/base-activated switching, together with the induced AIE-effects, further enabled the accomplishment of a responsive superorganogelator. In nonpolar solvents, a blue-fluorescent supramolecular gel was formed upon addition of acid to the E-isomer suspension. The gelation could be reversed by addition of base, and the overall, reversible process could be repeated at least five cycles.
|
|
| 3. |
- Zhu, Baoyi, et al.
(författare)
-
Array profiling reveals contribution of Cthrc1 to growth of the denervated rat urinary bladder
- 2018
-
Ingår i: American Journal of Physiology - Renal Physiology. - : American Physiological Society. - 1931-857X .- 1522-1466. ; 314:5, s. f893-f905
-
Tidskriftsartikel (refereegranskat)abstract
- Bladder denervation and bladder outlet obstruction are urological conditions that cause bladder growth. Transcriptomic surveys in outlet obstruction have identified differentially expressed genes, but similar studies following denervation have not been done. This was addressed using a rat model in which the pelvic ganglia were cryo-ablated followed by bladder microarray analyses. At 10 days following denervation, bladder weight had increased 5.6-fold, and 2,890 mRNAs and 135 micro-RNAs (miRNAs) were differentially expressed. Comparison with array data from obstructed bladders demonstrated overlap between the conditions, and 10% of mRNAs changed significantly and in the same direction. Many mRNAs, including collagen triple helix repeat containing 1 (Cthrc1), Prc1, Plod2, and Dkk3, and miRNAs, such as miR-212 and miR-29. resided in the shared signature. Discordantly regulated transcripts in the two models were rare, making up for <0.07% of all changes, and the gene products in this category localized to the urothelium of normal bladders. These transcripts may potentially be used to diagnose sensory denervation. Western blotting demonstrated directionally consistent changes at the protein level, with increases of, e.g., Cthrc1, Prc1, Plod2, and Dkk3. We chose Cthrc1 for further studies and found that Cthrcl was induced in the smooth muscle cell (SMC) layer following denervation. TGF-beta 1 stimulation and miR-30d-5p inhibition increased Cthrc1 in bladder SMCs, and knockdown and overexpression of Cthrc1 reduced and increased SMC proliferation. This work defines common and distinguishing features of bladder denervation and obstruction and suggests a role for Cthrc1 in bladder growth following denervation.
|
|
