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Foam formation in a gas–liquid stirred tank: Impact of impeller type and operating conditions
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Regulatory mechanisms of ER body formation and its function in Brassicaceae plants
No full textInternational audienceEndoplasmic reticulum (ER) bodies are unique ER subdomains with a spindle-shaped structure in Brassicaceae, Cleomaceae, and Capparaceae plants, and they accumulate high levels of β-glucosidases (BGLUs). ER body-localized BGLUs are crucial for the hydrolysis of glucosinolates that are responsible for the chemical defense. In Arabidopsis thaliana, ER body-deficient mutants are vulnerable to non-herbivorous arthropods and non-pathogenic fungi, and display altered root microbiota assembly. ER bodies are predominantly observed in seedlings and roots, as well as in the epidermal cells above leaf midveins and margins. ARABIDOPSIS THALIANA MERISTEM LAYER1 (ATML1) transcription factor controls ER body accumulation in leaves through the activation of the NAI1 transcription factor, which upregulates the expression of ER body-related genes. ER bodies are further induced by wounding, indicating that their accumulation is also controlled in response to environmental signals. Jasmonate plays a key role in regulating ER body induction through CORONATINE INSENSITIVE1 (COI1), and the transcription factors MYC2, MYC3, and MYC4, which further control the expression of MYB47 and MYB95, key regulators of ER body-related genes. The conservation of orthologous and paralogous genes among ER body-related genes is observed in Brassicaceae plant genomes, indicating the conservation of ER body accumulation mechanisms among Brassicaceae species
Microstructural dependence and reduction of the size of the representative volume element in polycrystals: Case of cubic and hexagonal elasticity
No full textInternational audienceClosed-form expressions of the size of the representative volume element are determined for computing the elastic moduli of polycrystalline materials with cubic and hexagonal crystal symmetries. The size of the representative volume element corresponds to the number of grains needed in a polycrystal, N, to compute a property of the material (an elastic modulus) with a given error, e. The elastic moduli are computed using periodic polycrystals and finite element simulations. A typical, experimental grain-growth microstructure is considered as a reference case, and the microstructure properties are then modified. This allows us to determine the effect of the different microstructural properties on the error (e). The relationship between the error (e) and the size of the representative volume element (N) is shown to be e=a/√N, where a depends on both the crystal anisotropy of the material and the variability of the effective orientation distribution of the microstructure. This variability in turn arises from the cumulative effects of two main sources: the random sampling of the orientation distribution and the grain size distribution. Then, general expressions of a applying to all cubic and hexagonal-symmetry materials are determined. It is demonstrated that reducing the microstructural variability does not affect the computed elastic modulus values, thereby enabling the use of polycrystals with significantly fewer grains. For copper, the error in the computed shear modulus (e) can be reduced by a factor of 9.4 (for a given number of grains in a polycrystal, N), or equivalently, the number of grains needed in a polycrystal (N) can be reduced by a factor of about 90 (for a given error, e). Similar results are obtained for (hexagonal-symmetry) titanium and zinc, for which N can be reduced by factors of 140 and 45, respectively. The results also indicate that the size of the representative volume element (N) is smaller for hexagonal-symmetry materials than for cubic-symmetry materials, and smaller for the bulk modulus than for the shear modulus
Observing object circulation as movement using participants’ visual ethnography: theoretical relevance and research protocol
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Organizing collective political action in a world in polycrisis: insights from Hannah Arendt and John Dewey
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Respective impacts of global warming, permafrost thaw and urban sprawl on debris-flow risk: Insights from the Dorfbach Torrent, Swiss Alps
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From policy to practice in cervical cancer prevention in Reunion Island
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Plant conservation in a changing Mediterranean world
No full textInternational audienceSocietal Impact Statement The Mediterranean is one of five climatic regions on the planet characterised by a prolonged summer drought, exceptional plant diversity and high rates of endemism. We provide a framework to link the ecology of plant species conservation in the context of rapid and extreme climate deregulation to a philosophical typology of temporal attitudes (i.e., past, present and future). We argue that we must go beyond the historical heritage approach to embrace conservation action in a changing world. We review pragmatic and original ways to deepen social awareness for plant conservation, aligned with the three temporal themes. It is time to bring plants to the forefront of conservation action. Summary In this Thomas Review, we provide a structure that links ecological science of plant species conservation to a philosophical typology of temporal attitudes of scientists, i.e. ways of considering the inscription of one's action in time, with a preference for a temporal dimension in the past, the present or the future. We developed this framework to illustrate original ways of deepening social awareness for plant conservation. In section 1, we widen ecological and evolutionary foundations for plant conservation based on the historical floristic heritage to embrace the need to protect species at their range limits and the need to monitor the effects of extreme climate events. The processes that shape diversity and adaptation are central to this approach. Section 2 describes three temporal attitudes associated with the above three conservation themes. The remembrance attitude is characterised by its interest in the long‐term history of plant diversity. The anticipation attitude relies on climate scenarios and expected species distribution changes. Finally, a prudent attitude consists of making regular observations of ongoing change that relies on an iterative temporality of a continually renewed present. In section 3, we illustrate pragmatic and original ways to deepen social awareness for plant conservation in line with the three temporal themes. We conclude with a comment on the uncertainties surrounding conservation science and the need for confidence to act locally.El Mediterráneo es una de las cinco regiones climáticas del planeta caracterizadas por una prolongada sequía estival, una diversidad vegetal excepcional y altos índices de endemismo. En un contexto de desregulación climática acelerada y extrema, proponemos un marco para vincular la ecología de la conservación de especies vegetales con una tipología filosófica de actitudes temporales (pasado, presente y futuro). Sostenemos que es necesario superar un enfoque rígido centrado en el patrimonio natural y estructurar acciones de conservación adecuadas a un mundo en transformación. Examinamos medios pragmáticos y originales para fortalecer la concientización social sobre la conservación de las plantas en relación con estas tres dimensiones temporales. Ha llegado el momento de situar a las plantas en el centro de las estrategias de conservación.La Méditerranée est l'une des cinq régions climatiques de la planète caractérisées par une sécheresse estivale prolongée, une diversité végétale exceptionnelle et des taux élevés d'endémisme. Dans un contexte de dérégulation climatique accélérée et extrême, nous proposons un cadre pour relier l'écologie de la conservation des espèces végétales, à une typologie philosophique des attitudes temporelles (passé, présent et futur). Nous défendons l'idée qu'il faut dépasser une approche figée du patrimoine naturel et structurer des actions de conservation dans un monde en mutation. Nous passons en revue des moyens pragmatiques et originaux de renforcer la sensibilisation sociale à la conservation des plantes, en lien avec ces trois dimensions temporelles. Le moment est venu de mettre les plantes au cœur des stratégies de conservation.Il Mediterraneo è una delle cinque regioni climatiche del pianeta caratterizzate da una siccità estiva prolungata, un'eccezionale diversità vegetale e alti tassi di endemismo. In un contesto di sregolamento climatico, rapido ed estremo, proponiamo un quadro per collegare l'ecologia della conservazione delle specie vegetali a una tipologia filosofica delle attitudini temporali (passato, presente e futuro). Sosteniamo che occorre superare un approccio statico al patrimonio naturale e strutturare azioni di conservazione in un mondo in trasformazione. Esaminiamo modalità pragmatiche e originali per rafforzare la consapevolezza sociale sulla conservazione delle piante, in relazione a queste tre dimensioni temporali. È giunto il momento di mettere le piante al centro delle strategie di conservazione
DUALF-D: Disentangled dual-hyperprior approach for light field image compression
No full textInternational audienceLight field (LF) imaging captures spatial and angular information, offering a 4D scene representation enabling enhanced visual understanding. However, high dimensionality and redundancy across spatial and angular domains present major challenges for compression, particularly where storage, transmission bandwidth, or processing latency are constrained. We present a novel Variational Autoencoder (VAE)-based framework that explicitly disentangles spatial and angular features using two parallel latent branches. Each branch is coupled with an independent hyperprior model, allowing more precise distribution estimation for entropy coding and finer rate-distortion control. This dual-hyperprior structure enables the network to adaptively compress spatial and angular information based on their unique statistical characteristics, improving coding efficiency. To further enhance latent feature specialization and promote disentanglement, we introduce a mutual information-based regularization term that minimizes redundancy between the two branches while preserving feature diversity. Unlike prior methods relying on covariance-based penalties prone to collapse, our information-theoretic regularizer provides more stable and interpretable latent separation. Experimental results on publicly available LF datasets demonstrate our method achieves strong compression performance, yielding an average BD-PSNR gain of 2.91 dB over HEVC and high compression ratios (e.g., 200:1). Additionally, our design enables fast inference, with a total end-to-end time over 19x faster than the JPEG Pleno standard, making it well-suited for real-time and bandwidth-sensitive applications. By jointly leveraging disentangled representation learning, dual-hyperprior modeling, and information-theoretic regularization, our approach offers a scalable, effective solution for practical light field image compression.</div
