| 1. |
- Alwmark, S., et al.
(författare)
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Diverse Lava Flow Morphologies in the Stratigraphy of the Jezero Crater Floor
- 2023
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Ingår i: Journal of Geophysical Research: Planets. - 2169-9097. ; 128:7
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Tidskriftsartikel (refereegranskat)abstract
- We present a combined geomorphologic, multispectral, and geochemical analysis of crater floor rocks in Jezero crater based on data obtained by the Mast Camera Zoom and SuperCam instruments onboard the NASA Mars 2020 Perseverance rover. The combined data from this analysis together with the results of a comparative study with geologic sites on Earth allows us to interpret the origins of rocks exposed along the Artuby ridge, a ∼900 m long scarp of lower Máaz formation rocks. The ridge exposes rocks belonging to two morphologically distinct members, Artuby and Rochette, both of which have basaltic composition and are spectrally indistinguishable in our analysis. Artuby rocks consist of morphologically distinct units that alternate over the ridge, bulbous, hummocky, layers with varying thicknesses that in places appear to have flowed over underlying strata, and sub-planar thinner laterally continuous layers with variable friability. The Rochette member has a massive appearance with pronounced pitting and sub-horizontal partings. Our findings are most consistent with a primary igneous emplacement as lava flows, through multiple eruptions, and we propose that the thin layers result either from preferential weathering, interbedded ash/tephra layers, ʻaʻā clinker layers, or aeolian deposition. Our analyses provide essential geologic context for the Máaz formation samples that will be returned to Earth and highlight the diversity and complexity of geologic processes on Mars not visible from orbit.
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| 2. |
- Loisel, J., et al.
(författare)
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Expert assessment of future vulnerability of the global peatland carbon sink
- 2021
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Ingår i: Nature Climate Change. - : Springer Science and Business Media LLC. - 1758-678X .- 1758-6798. ; 11:1, s. 70-77
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Tidskriftsartikel (refereegranskat)abstract
- Peatlands are impacted by climate and land-use changes, with feedback to warming by acting as either sources or sinks of carbon. Expert elicitation combined with literature review reveals key drivers of change that alter peatland carbon dynamics, with implications for improving models. The carbon balance of peatlands is predicted to shift from a sink to a source this century. However, peatland ecosystems are still omitted from the main Earth system models that are used for future climate change projections, and they are not considered in integrated assessment models that are used in impact and mitigation studies. By using evidence synthesized from the literature and an expert elicitation, we define and quantify the leading drivers of change that have impacted peatland carbon stocks during the Holocene and predict their effect during this century and in the far future. We also identify uncertainties and knowledge gaps in the scientific community and provide insight towards better integration of peatlands into modelling frameworks. Given the importance of the contribution by peatlands to the global carbon cycle, this study shows that peatland science is a critical research area and that we still have a long way to go to fully understand the peatland-carbon-climate nexus.
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| 3. |
- Mollier, P., et al.
(författare)
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Promoterless GUS expression in a large number of Arabidopsis thaliana transformants obtained by the in planta infiltration method
- 1995
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Ingår i: Comptes rendus de l'Académie des sciences. Série 3, Sciences de la vie. - 0764-4469 .- 1878-5565. ; 318:4, s. 465-474
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Tidskriftsartikel (refereegranskat)abstract
- A large number of Arabidopsis thaliana transformant T2 families were obtained using in planta infiltration method. A T-DNA containing 2 resistance genes for the selection of the transformants and the promoterless gus gene for promoter-trapping was transferred from the Agrobacterium cells to the plant genome. The GUS activity of each transformant was tested histochemically an 15-day-old seedlings grown in vitro either under light or dark conditions. For each transformant, the GUS activity spatial pattern in plant organs and tissues and the light influence on the GUS activity were studied. Vast variation of GUS activity spatial patterns was observed. A majority of transformants displayed a strictly light-dependent GUS activity Lastly, it was seen that certain transformants could give variable GUS patterns at different stages of development. These spatial, temporal and light-dependent GUS activity features allowed us to characterize the activity of the putative corresponding promoter.
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| 4. |
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