1. |
|
|
2. |
- Katlein, Christian, et al.
(författare)
-
Platelet Ice Under Arctic Pack Ice in Winter
- 2020
-
Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 47:16
-
Tidskriftsartikel (refereegranskat)abstract
- The formation of platelet ice is well known to occur under Antarctic sea ice, where subice platelet layers form from supercooled ice shelf water. In the Arctic, however, platelet ice formation has not been extensively observed, and its formation and morphology currently remain enigmatic. Here, we present the first comprehensive, long-term in situ observations of a decimeter thick subice platelet layer under free-drifting pack ice of the Central Arctic in winter. Observations carried out with a remotely operated underwater vehicle (ROV) during the midwinter leg of the MOSAiC drift expedition provide clear evidence of the growth of platelet ice layers from supercooled water present in the ocean mixed layer. This platelet formation takes place under all ice types present during the surveys. Oceanographic data from autonomous observing platforms lead us to the conclusion that platelet ice formation is a widespread but yet overlooked feature of Arctic winter sea ice growth.
|
|
3. |
- Peret, Benjamin, et al.
(författare)
-
Sequential induction of auxin efflux and influx carriers regulates lateral root emergence
- 2013
-
Ingår i: Molecular Systems Biology. - : Nature Publishing Group. - 1744-4292 .- 1744-4292. ; 9, s. Article number 699-
-
Tidskriftsartikel (refereegranskat)abstract
- In Arabidopsis, lateral roots originate from pericycle cells deep within the primary root. New lateral root primordia ( LRP) have to emerge through several overlaying tissues. Here, we report that auxin produced in new LRP is transported towards the outer tissues where it triggers cell separation by inducing both the auxin influx carrier LAX3 and cell-wall enzymes. LAX3 is expressed in just two cell files overlaying new LRP. To understand how this striking pattern of LAX3 expression is regulated, we developed a mathematical model that captures the network regulating its expression and auxin transport within realistic three-dimensional cell and tissue geometries. Our model revealed that, for the LAX3 spatial expression to be robust to natural variations in root tissue geometry, an efflux carrier is required-later identified to be PIN3. To prevent LAX3 from being transiently expressed in multiple cell files, PIN3 and LAX3 must be induced consecutively, which we later demonstrated to be the case. Our study exemplifies how mathematical models can be used to direct experiments to elucidate complex developmental processes.
|
|