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Vers une viticulture sans pesticides : analyse du microbiote des vignes et des sols viticoles pour développer le biocontrôle microbien du mildiou
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A Clustered Approach to Adaptive Kriging Particle Filter for Magnetic Field-Aided Navigation
No full textInternational audienceAutonomous navigation is a key aspect in unmanned mobile robotics, where accurate and efficient localisation and tracking are crucial. One of the challenges in these situations is the reliable use of sensor data, particularly in environments where GNSS is unavailable. Magnetometric navigation provides a promising alternative by leveraging the anomalies of the Earth's magnetic field. However, accurate estimation in such settings is hindered by noises, non-linearities and scarcity of environmental information. Gaussian process regression-based particle filtering can be considered to alleviate these difficulties.In this paper, we propose to improve Gaussian process-based particle filtering techniques by introducing a clustering step to select the relevant training data, improving their computational efficiency and accuracy in the presence of spatial nonstationarities. An auxiliary particle filter is considered due to its robustness to particle degeneracy.The approach was validated on simulated magnetometric data for an unmanned aerial vehicle. Numerical results show that the clustering step greatly reduces the computational cost of the regression while maintaining the accuracy and convergence speed of the particle filter, demonstrating that this technique offers significant advantages for real-time autonomous navigation
Transatlanticité et extraterritorialité chez Alain Mabanckou : une esthétique de la langue d’écriture atavico-altéritaire
No full textInternational audienceThis study looks at two novels by Alain Mabanckou, Petit Piment (2015) and Les Cigognessont immortelles (2018), to analyze how the author inscribes his writing in the popular parlersof Pointe-Noire. Through a language nourished by proverbs, African orality and localexpressions, Mabanckou valorizes a deep cultural rootedness while developing an aesthetic ofopenness towards the Other. His writing is both atavistic, faithful to Congolese memories, andalteritarian, open to cultural cross-fertilization, thus joining the Afropolitan dynamic. Drawing2on the reflections of Jean-Jacques Séwanou Dabla, Édouard Glissant and Achille Mbembe,this study shows that transatlanticity and exterritoriality mark Mabanckou's language: hewrites from “elsewhere” without severing his ties with his native land. His approachdeconstructs the fixed identities inherited from colonialism, by valorizing a mobile, hybridand creative identity. The analysis is structured around three approaches: poetics and stylistics(Gérard Genette), geopoetics (Édouard Glissant) and postcolonial criticism (AchilleMbembe). In this way, Mabanckou contributes to a decentered vision of the world andredefines notions of belonging, origin and literary space, creating a cross-border languagecapable of bringing Africa, Europe and the Americas into dialogue.Cette étude s’intéresse à deux romans d’Alain Mabanckou, Petit Piment (2015) et LesCigognes sont immortelles (2018), pour analyser comment l’auteur inscrit son écriture dansles parlers populaires de Pointe-Noire. À travers une langue nourrie de proverbes, d’oralitéafricaine et d’expressions locales, Mabanckou valorise un enracinement culturel profond touten développant une esthétique d’ouverture vers l’Autre. Son écriture est à la fois atavique,fidèle aux mémoires congolaises, et altéritaire, ouverte au métissage culturel, rejoignant ainsila dynamique afropolitaine. S'inspirant des réflexions de Jean-Jacques Séwanou Dabla,Édouard Glissant et Achille Mbembe, cette étude montre que la transatlanticité etl’exterritorialité marquent la langue de Mabanckou : il écrit depuis "ailleurs" sans couper sesliens avec sa terre natale. Sa démarche déconstruit les identités fixes héritées du colonialisme,en valorisant une identité mobile, hybride et créatrice. Trois approches structurent l'analyse :poétique et stylistique (Gérard Genette), géopoétique (Édouard Glissant) et critiquepostcoloniale (Achille Mbembe). Ainsi, Mabanckou participe à une vision décentrée dumonde et redéfinit les notions d’appartenance, d’origine et d’espace littéraire, créant unelangue transfrontalière, capable de faire dialoguer l’Afrique, l’Europe et les Amériques
Reed-Muller codes in the sum-rank metric
No full textInternational audienceWe introduce the sum-rank metric analogue of Reed-Muller codes, which we called linearized Reed-Muller codes, using multivariate Ore polynomials. We study the parameters of these codes, compute their dimension and give a lower bound for their minimum distance. Our codes exhibit quite good parameters, respecting a similar bound to Reed-Muller codes in the Hamming metric. Finally, we also show that many of the newly introduced linearized Reed-Muller codes can be embedded in some linearized Algebraic Geometry codes, recently defined in [Algebraic geometry codes in the sum-rank metric, IEEE Trans. Inf. Theory70 (2024) 3345–3356], a property which could turn out to be useful in light of decoding
Ecological Stress, Adaptation & Innovation: Hunter-Gatherers to Early Farmers in the Horn of Africa
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Peripheral artery disease.
No full textInternational audiencePeripheral artery disease (PAD) is characterized by blockage of the arteries that supply the lower extremities, often occurring as a result of atherosclerosis and thrombosis. PAD affects approximately 230 million people worldwide, with a growing prevalence owing to population ageing and concomitant cardiovascular risk factors, including smoking, diabetes mellitus, hypertension and dyslipidaemia. Patients with PAD have an increased risk of major cardiovascular and limb events, and substantially poorer walking performance compared with those without PAD. The screening and identification of PAD involves clinical and imaging assessments of disease extent and severity and stratification of individual risk to ensure appropriate management. Patients with PAD should be treated with guideline-directed medical therapy (GDMT), including antithrombotic, lipid-lowering, glucose-lowering and anti-hypertensive therapies, and exercise therapies that aim to improve function as well as cardiovascular and limb outcomes. For patients with compromised limb viability, such as acute and chronic limb-threatening ischaemia, or severe functional impairment that does not improve with exercise training, lower extremity revascularization is recommended. Given the complexity of PAD management, a multidisciplinary vascular team is required to achieve the best individualized treatment. Further research efforts should focus on reducing ischaemic events and health disparities and on optimizing the implementation of GDMT and exercise therapy, as well as improving the quality of life in patients with PAD
An Improved Threshold Homomorphic Cryptosystem Based on Class Groups
No full textInternational audienceWe present distributed key generation and decryption protocols for an additively homomorphic cryptosystem based on class groups, improving on a similar system proposed by Braun, Damgård, and Orlandi at CRYPTO '23. Our key generation is similarly constant round but achieves lower communication complexity than the previous work. This improvement is in part the result of relaxing the reconstruction property required of the underlying integer verifiable secret sharing scheme. This eliminates the reliance on potentially costly proofs of knowledge in unknown order groups. We present a new method to batch zero-knowledge proofs in unknown order groups which strengthens these improvements. We also present a protocol which is proven secure against adaptive adversaries in the single inconsistent player (SIP) model. Our protocols are secure in the universal composability (UC) framework and provide guaranteed output delivery. We demonstrate the relative efficiency of our techniques by presenting the running times and communication costs associated with our implementation of the statically secure protocol and provide a direct comparison with alternate state of the art constructions
Targeted design of organic Janus particles for improved photocatalytic hydrogen evolution
No full textInternational audienceOrganic bulk heterojunction particles are decorated in a well-controlled way with metals by using light-assisted bipolar electrodeposition to yield Janus particles. Their asymmetric character leads to significantly enhanced photocatalytic hydrogen evolution reaction. The organic particles are first synthesized via miniemulsion, tuning their size by carefully controlling various preparation parameters. Subsequently, the synergistic effect of an electric field and light is explored for the site-selective bipolar electrochemical deposition of different metals (Pt, Au or Pd). Photocatalytic tests reveal that in the case of platinum, the resulting Janus particles significantly outperform particles randomly covered with metal, as well as unmodified particles, showing an increase in hydrogen evolution efficiency by up to 500%. This superior performance is attributed to an enhanced charge carrier separation in the Janus structure, where Pt, confined at one side, facilitates more efficient electron shuttling and transfer. This work constitutes the first study reporting a promising approach for designing novel metal-organic Janus particles to boost photocatalytic hydrogen evolution and opens up new perspectives for optimizing the design of various other hybrid systems for sustainable energy conversion
Polymorphism and singularity of the Second Mesolithic of Southern France
No full textInternational audienceBetween the middle of the 7th and 6th millennia BCE, with the spread of the « Blade and Trapezes Complex « (BTC), southern France can be divided into two main groups, based on lithic production. In the East, in from the Mediterranean to the northern Alps, the Castelnovian complex, first defined by Max Escalon de Fonton, is characterised by the production of regular blades produced by pressure or indirect percussion, from which various types of trapezoidal, often asymmetrical, arrowheads were later derived. To the West, from the plains of Roussillon to the Atlantic coast, the so-called absence of laminar production and the existence of an original type of armature, such as « Gazel points » or « Bastard points », testify to the presence of another cultural sphere. During the 80's, some referred to as the ‘Cuzoul Gazel group', a notion now abandoned for lack of internal coherence and chronlogical inconstancy. This Second Mesolithic of Occitania and Aquitaine is actuly under revision due to a major documentary renewal, with the excavation of several sites and the revision of other lithic and chronostratigraphic assemblages, especially in the area between the Rhône Valley and the Aude. Our talk will therefore provide an opportunity to take stock of the available data and to determine whether or not these industries are original in terms of the spread of the blade and trapeze complex
NaSICON NaFe2PO4(SO4)2 revisited: insights into the crystal structure and electrochemical performance
No full textInternational audienceWith the aim to meet the needs for positive electrode materials for Na-ion batteries, based on abundant elements, synthesis routes using two different Fe3+ precursors were explored for the preparation of a pure mixed phosphate-sulfate NaSICON-type compound, NaFe23+PO4(SO4)2 (NFPS). Interestingly, a structural model described in the R-3 space group is found from careful analysis of X-ray, neutron, and electron diffraction. Atoms P and S (and thus, PO4 and SO4 anionic groups) are statistically distributed within the polyanionic framework, with a splitting of the conventional Na2 3b site into two positions 3a and 18f. Na-half cells with NFPS as a positive electrode material delivered 126 mAh/g, nearly the full theoretical capacity, at a cycling rate of D/30–C/30 (i.e., the exchange of 2 Na+ in 30 h).</p