| 1. |
- Mialon, B., et al.
(author)
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Benchmarking the prediction of dynamic derivatives : Wind tunnel tests, validation, acceleration methods
- 2010
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In: AIAA Atmospheric Flight Mechanics Conference 2010. - 9781624101519
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Conference paper (peer-reviewed)abstract
- The dynamic derivatives are widely used in linear aerodynamic models which are considered to determine the flying qualities of an aircraft: The ability to predict them reliably, quickly and sufficiently early in the design process is more and more important. This paper describes some experimental and computational activities dealing with the determination of dynamic derivatives. The work has been carried out within the FP6 European project SimSAC. Numerical and experimental results are compared for two aircraft configurations: The generic civil transport aircraft, wing-fuselage-tail configuration DLR-F12 and a generic Transonic CRuiser (TCR), which is a canard configuration. Static and dynamic wind tunnel tests have been carried out for both configurations and are briefly described. The data base generated for the TCR configuration includes small amplitude oscillations, dedicated to the determination of dynamic derivatives, and large amplitude oscillations, in order to investigate the dynamic effects on nonlinear aerodynamic characteristics. The influence of the canard has been investigated. Dynamic derivatives have been determined on both configurations with a large panel of tools, from linear aerodynamic (Vortex Lattice Methods) to CFD (unsteady Reynolds-Averaged Navier-Stokes solvers). Strong limitations of linear aerodynamic tools are observed for the canard configuration. A specific attention is paid to acceleration techniques in CFD methods, which allow the computational time to be dramatically reduced while keeping a satisfactory accuracy.
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| 2. |
- Rodriguez-Fernandez, N., et al.
(author)
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Paving the Road to Flex and Biomass : The Land Surface Carbon Constellation Study
- 2022
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In: IGARSS 2022 - 2022 IEEE International Geoscience and Remote Sensing Symposium. - 9781665427920 ; 2022-July, s. 5571-5574
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Conference paper (peer-reviewed)abstract
- Remote sensing observations of variables related to vegetation at microwave and optical/infrared wavelengths are presented over three regions in Europe in the Iberian peninsula, northern Finland and central Europe. They include the instrumented sites of Las Majadas, Sodankyla and Reusel. The final goal is to better constrain land carbon cycle models using the complementarities of vegetation optical depth derived at different frequencies from active and passive instruments (related to vegetation water content and biomass) as well as optical data of the fraction of absorbed photosynthetically active radiation or solar induced fluorescence, closely linked to photosynthesis. The first results confirm this complementarity. For instance, time series of different variables exhibit positive correlations in some areas and negative correlations in other areas.
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| 3. |
- Wigneron, J. P., et al.
(author)
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SMOS-IC : Current status and overview of soil moisture and VOD applications
- 2018
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In: 2018 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2018 - Proceedings. - 9781538671504 ; 2018-July, s. 1451-1454
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Conference paper (peer-reviewed)abstract
- In 2017, the new SMOS-IC retrieval product of soil moisture (SM) and L-band Vegetation Optical depth (L-VOD) was developed. This product relies on a two-parameter inversion of the L-MEB model (L-band Microwave Emission of the Biosphere) which requires little ancillary information and was found to be accurate, making it very well-suited for application in agriculture, hydrology, climate and vegetation monitoring. In this communication we present recent improvements in the SMOS-IC retrieval algorithm and recent applications using the soil moisture or VOD retrievals from the SMOS-IC data set. SMOS-IC SM is available at the French CATDS center.
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| 4. |
- Holmström, Tim H., et al.
(author)
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c-Jun supports ribosomal RNA processing and nucleolar localization of RNA helicase DDX21
- 2008
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In: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 283:11, s. 7046-7053
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Journal article (peer-reviewed)abstract
- The molecular mechanisms by which the AP-1 transcription factor c-Jun exerts its biological functions are not clearly understood. In addition to its well established role in transcriptional regulation of gene expression, several reports have suggested that c-Jun may also regulate cell behavior by non-transcriptional mechanisms. Here, we report that small interfering RNA-mediated depletion of c-Jun from mammalian cells results in inhibition of 28 S and 18 S rRNA accumulation. Moreover, we show that c-Jun depletion results in partial translocation of RNA helicase DDX21, implicated in rRNA processing, from the nucleolus to the nucleoplasm. We demonstrate that DDX21 translocation is rescued by exogenous c-Jun expression and that c-Jun depletion inhibits rRNA binding of DDX21. Furthermore, the direct interaction between c-Jun and DDX21 regulates nucleolar localization of DDX21. These results demonstrate that in addition to its transcriptional effects, c-Jun regulates rRNA processing and nucleolar compartmentalization of the rRNA processing protein DDX21. Thus, our results demonstrate a nucleolar mechanism through which c-Jun can regulate cell behavior. Moreover, these results suggest that the phenotypes observed previously in c-Jun-depleted mouse models and cell lines could be partly due to the effects of c-Jun on rRNA processing.
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| 5. |
- Kaminski, T., et al.
(author)
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Constraining terrestrial carbon fluxes through assimilation of SMOS products
- 2018
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In: 2018 IEEE International Geoscience and Remote Sensing Symposium, IGARSS 2018 - Proceedings. - 9781538671504 ; 2018-July, s. 1455-1458
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Conference paper (peer-reviewed)abstract
- The ongoing ESA funded'SMOS + Vegetation' project combines a retrieval component that aims at further improving the SMOS VOD product with an assimilation component that aims at demonstrating the added value of this product in constraining simulated land surface fluxes of carbon dioxide. This contribution focuses on the project's modelling and assimilation component. We describe the construction of dedicated observation operators that link the state of the terrestrial biosphere model to simulated VOD and surface layer soil moisture. We present our carbon assimilation system around a terrestrial biosphere model and demonstrate its operation through simultaneous assimilation of the SMOS VOD product over seven sites covering a range of plant functional types.
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| 6. |
- Scholze, M., et al.
(author)
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Mean European Carbon Sink Over 2010–2015 Estimated by Simultaneous Assimilation of Atmospheric CO2, Soil Moisture, and Vegetation Optical Depth
- 2019
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In: Geophysical Research Letters. - 0094-8276. ; 46:23, s. 13796-13796
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Journal article (peer-reviewed)abstract
- The northern land biosphere is believed to be the main global sink of CO2, but the contribution of Europe is uncertain. While bottom-up estimates and inverse atmospheric transport studies based on atmospheric CO2 observed in situ or from space by OCO-2 point to a moderate rate of uptake, some other inversions based on remotely sensed atmospheric CO2 from GOSAT/SCIAMACHY and biomass estimates from passive microwave satellite data point to a large sink of around 1 Gt C/yr. We present results from combining both approaches in a data assimilation framework, inverting a biosphere model against in situ atmospheric CO2 and passive microwave measurements. When assimilating all observations, we estimate a European carbon sink of 0.303 ± 0.083 Gt C/yr for 2010–2015. The result agrees with other bottom-up studies and atmospheric inversions using in situ CO2 or OCO-2 observations pointing to potential data problems when using observations from GOSAT or SCIAMACHY to estimate the European CO2 sink.
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