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Toward robust linear implicit schemes for steady state hypersonic flows
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Basque Pelota and Europeanization: The Actions and Representations of Actors Involved in Two Cross-Border Projects in a Euroregion
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Linearization of Intermodulation Distortion Using a Derivative Extended Model and Three-Tone Signal Identification
No full textInternational audienceThis article deals with the linearization of a radio frequency (RF) receiver chain through digital processing. An extension of a state-of-the-art distortion model is proposed, based on functions of the derivative of the signal. These are shown to translate to dependencies of the instantaneous frequency and instantaneous power of the processed signal. In addition, a three-tone signal identification method is presented, adapted to the estimation of the parameters of the proposed model. Finally, the construction of a measurement bench suitable for the validation of the identification and linearization method is described. Identification and linearization are done iteratively, based on the output signal of the system of interest. Results comparing the linearization using state-of-the-art model and our extended version show an improvement of the instantaneous dynamic range of up to 10 dB
Cake formation in the filtration of associative microgel suspensions
No full textInternational audienceIn this work, we investigate the jamming behavior of associative microgel suspensions used as fluid loss additives in model porous media. We first construct a phase diagram using drying experiments, followed by characterization of the suspensions' rheology and the permeability of the filter cakes at maximum microgel concentration. Microfluidic devices are designed for frontal and lateral flow filtration with pore sizes comparable to or slightly larger than the microgel particles. Microscopic observations reveal irreversible aggregation as the particles pass through pores, leading to cake formation inside and at the exit of the pores-contrary to the classical view of cake formation. Flow in linear channels of similar pore size, however, does not cause jamming, suggesting that extensional shear plays a crucial role. We hypothesize that extensional flows promote the association of hydrophobic groups by unfolding dangling chains, resulting in lowpermeability filter cakes with self-adaptive properties for larger pore networks
La démarche scientifique à l’épreuve de l’inattendu et du malentendu
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Observations Of Multidecadal Gravel Beach Dynamics From Space
No full textInternational audienceGravel barrier systems are ubiquitous on mid-and high-latitude coasts and provide vital protection from coastal flooding and coastal erosion. They are highly dynamic systems that exhibit complex responses to hydrodynamic forcing over a range of timescales (hourly-monthly-decadal-centennial). Their dynamics differ greatly from those of sandy beaches yet have received considerably less attention in the literature, particularly at interannual to decadal scales. We use over four decades of satellite-derived shoreline (SDS) data to explore the long-term dynamic of 45 selected gravel systems around the United Kingdom and Ireland. Unlike most large-scale studies, we apply an SDS extraction methodology specifically tailored to gravel beaches to derive the long-term shoreline trends along 1554 shore-normal transects across our sites. Our findings indicate a great variability in shoreline trends, ranging from -4.73 m/year to +10.5 m/year with the majority of transects (62%) remaining stable over the study period (1984 -2023). Overall, 22% of transects showed statistically significant positive trends and 14% negative trends, resulting in an overall +0.36 m/year mean shoreline trend. Large scale climatic forcing seems to have a stronger control on the evolution of gravel nesses with 29% and 26% of transects having an average correlation of -0.36 and -0.34 with North Atlantic Oscillation and Atlantic Oscillation respectively, while open beaches showed the weakest relationship with climate forcing. Importantly, climate forcing did not seem to be a key driver of change in the regions with the highest rates of progradation
Minimal History-Deterministic Co-Buchi Automata: Congruences and Passive Learning
No full textInternational audienceAbu Radi and Kupferman (2019) demonstrated the efficient minimization of history-deterministic (transition-based) co-Büchi automata, building on the results of Kuperberg and Skrzypczak (2015). We give a congruence-based description of these minimal automata, and a self-contained proof of its correctness. We use this description based on congruences to create a passive learning algorithm that can learn minimal history-deterministic co-Büchi automata from a set of labeled example words. The algorithm runs in polynomial time on a given set of examples, and there is a characteristic set of examples of polynomial size for each minimal history-deterministic co-Büchi automaton
N-Terminal Stabilization of Radiolabeled Neurotensin Analogues for Improved Tumor Uptake
No full textInternational audiencePeptide-based radiopharmaceuticals targeting neurotensin-receptor-1 (NTS1) are mainly stabilized using chemical modifications at the NT[8-13] sequence, thus increasing the stability and the uptake of the corresponding radionuclide-macrocycle-linker-bioconjugate. We postulate that the introduction of the linker at the N-term part induces additional cleavage sites that can be further stabilized to achieve a prolonged uptake. Double (JMV 7259 and JMV 7222) and triple-stabilized neurotensin analogues (JMV 7258 and JMV 7490) were synthesized, radiolabeled, and evaluated on HT-29 cells (NTS1+ ). Nanomolar NTS1-affinity and high internalization rates were observed for all of the radiopharmaceuticals. Efflux was lower for radiolabeled JMV 7490. Consequently, [111In]In-JMV 7490 showed uptake of 5.86 ± 0.86 and 3.65 ± 0.29% ID/g of tissue in HT-29 xenografts at 1 and 4 h, respectively. We have successfully shown that high and persistent uptake of NTS 1positive tumor cells is achievable by stabilization of the N-term part. Efflux also appears to be a critical parameter for the successful targeting of NTS1 using radiopharmaceuticals
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No full textThe work of Rajanikanta Bardaloi, recognized as the first Assamese novelist, is distinguished by a style that closely mirrors spoken language. His writing is structured around two pivotal historical moments: the Moran uprising between 1769 and 1805 (the Moamoria Rebellion), and the Burmese invasion between 1817 and 1825. These two events mark the beginning of the decline of the Ahom dynasty, which had gradually established its rule over the whole of Assam after entering the region from Burma in the thirteenth century. By focusing on the Burmese invasion, experienced as a collective trauma due to the atrocities committed by the army, Bardaloi adopts an ambiguous stance: while the British are portrayed as liberators who freed the Assamese from Burmese domination, their customs are not to be emulated. In this way, his work takes on an almost ethnographic dimension through the interweaving of social and cultural realities, transforming into a kind of national hymn where his characters’ songs intertwine fictional love stories with historical and political events.L'oeuvre de Rajanikanta Bardaloi, reconnu comme le premier auteur des romans assamais, se caractérise par un style proche de la langue parlée. Elle est construite autour de deux dates pivots : la révolution des Moran entre 1769 et 1805 (The Moamoria Rebellion) et l’invasion birmane entre 1817 et 1825. Ces deux évènements sont à l’origine du déclin des Ahom qui ont progressivement établi leur règne sur tout l’Assam en entrant par la Birmanie au XIIIe siècle. En focalisant son propos sur l’invasion birmane, vécue comme un traumatisme en raison des exactions de l’armée, Bardaloi assume une position ambiguë : si les Anglais sont décrits comme des sauveurs, lorsqu’ils libèrent les Assamais des Birmans, il n’est pas question de s’approprier leurs mœurs. À cette fin, son œuvre prend une dimension quasi ethnographique grâce à l’entrelacement des faits sociaux et culturels qu’il relate comme un hymne national en faisant chanter ses personnages entre des récits d’amour fictifs et des faits politiques réels
Transcriptional regulation by LKB1 in lung adenocarcinomas: Exploring oxidative stress, neuroglial and amino acid signatures
No full textInternational audienceLung adenocarcinoma (LUAD) is one of the most prevalent cancer types worldwide and has one of the poorest survival rates. Understanding its developpment is crucial for improving diagnosis, prognosis, and treatment. A key factor in LUAD is the frequent loss-of-function mutations in LKB1/STK11, a kinase that regulates metabolism. These mutations are linked to increased metastasis and worse clinical outcomes.In this study, we analyzed gene expression data from LUAD patients to explore how LKB1 mutations affect cancer behavior. We found that LKB1 mutations in KRAS-driven LUAD lead to widespread gene downregulation. By integrating avalaible protein interaction data, mass spectrometry analysis of LKB1 nuclear partners, and co-immunoprecipitations experiments, we identified BRG1, a chromatin activator and subunit of the BAF complex, as a nuclear partner of LKB1. Further analysis suggested that LKB1 mutations may impair BRG1 activity, disrupting chromatin regulation and gene expression.Notably, LUAD patients with mutated LKB1 showed gene expression patterns indicative of oxidative stress, defective neuronal-glial and neuroinflammation programs, and altered amino acid homeostasis. These changes resemble the roles LKB1 plays in neural crest stem cells, suggesting that LKB1 may reduce tumor aggressiveness in LUAD by maintaining a developmental gene expression program