Portail HAL-PSL
Not a member yet
293219 research outputs found
Sort by
Le genre Chlorophytum Ker Gawl. (Asparagales, Asparagaceae) à Madagascar, avec la description de 12 nouvelles espèces, 4 nouvelles sous-espèces et 1 nouvelle variété
No full textInternational audienceThe genus Chlorophytum Ker Gawl. (Asparagaceae) is revised taxonomically for Madagascar. It is a palaeotropical genus of more than 200 species, all of which are geophytes that are distributed throughout Africa, the Arabian Peninsula (Oman), Southeast Asia, the Indian subcontinent, China and Australia. We recognise 39 endemic taxa for Madagascar (30 species, 4 subspecies, 3 varieties and 2 potential species not formally named due to incomplete material). Descriptions and geographical data are provided for all taxa, of which 17 are newly described in this revision: 12 species (C. albociliatum sp. nov., C. aspidistrifolium sp. nov., C. basivaginatum sp. nov., C. candelabrum sp. nov., C. darainense sp. nov., C. helvillae sp. nov., C. meridionale sp. nov., C. nigrogranulosum sp. nov., C. nusbaumeri sp. nov., C. ranirisonii sp. nov., C. ratovosonii sp. nov., C. tolyanum sp. nov.); 4 subspecies (C. sofiense subsp. gautieri subsp. nov., C. graniticum subsp. ambrense subsp. nov., C. meridionale subsp. ihosyense subsp. nov., C. meridionale subsp. tulearense subsp. nov.); and 1 variety (C. madagascariense var. boinense var. nov.). Chlorophytum gramineum (Baker) H.Perrier, is based on an illegitimate name (Anthericum gramineum Baker), and is replaced by the later legitimate name, C. madagascariense Baker, that we consider to be a taxonomic synonym. We retain the varieties described by Perrier de la Bâthie within this species, transferring them to C. madagascariense, and we give a new name – C. madagascariense var. pervillei nom. nov. Furthermore, we lectotypify eight species: C. decaryanum, C. decipiens, C. dianellifolium, C. geayanum, C. graniticum, C. namorokense H.Perrier, C. sofiense, C. subligulatum, and two varieties: C. dianellifolium var. transiens and C. madagascariense var. sciaphilum comb. nov.). An identification key and preliminary conservation status assessments following IUCN Red List criteria are provided for all species
ComposeAnything: Composite Object Priors for Text-to-Image Generation
No full textInternational audienceCurrent text-to-image models struggle to generate scenes with many objects and complex relations. Training-time solutions such as layout conditioning or reinforcement learning improve compositional accuracy but often degrade image quality and realism by enforcing rigid constraints. To address this limitation, we introduce ComposeAnything, an inference-only framework that injects a structured composite object prior directly into the diffusion process. Rather than starting from random latent noises or performing expensive noise optimization, we construct a single 2.5D composite prior encoding strong object appearance, counts, sizes, and coarse depth-aware placement, and use it to initialize and guide one diffusion trajectory. This explicit prior is interpretable and editable in image space, enabling human-in-the-loop refinement by simply adjusting the composite. Our training-free, backbone-agnostic method improves compositional consistency on T2I-CompBench and NSR-1K benchmarks, particularly for complex prompts, while maintaining high visual quality compared to both training-based baselines and other inference-time methods
Diversification and historical biogeography of the Himalayan toad (Duttaphrynus himalayanus)
No full textInternational audienc
Coarse-grained physics-based modelling for tape casting of fuel-electrode supports in Solid Oxide Cells
No full textInternational audienceOptimising the tape casting process for fabricating NiO/YSZ cermet-based fuel-electrode supports in Solid Oxide Cells remains a resource-intensive challenge. Improving the green tape properties are often reliant on trial-and-error procedures or proprietary knowledge that is inaccessible to the broader scientific community. In this work, we use computational simulations as a powerful tool to link the manufacturing process to the final microstructure of the tape. A novel three-dimensional physics-based model is presented to simulate the slip preparation and the homogeneous drying process of the tape casting producing the fuel electrode support in Solid Oxide Cells. Our model is well-calibrated to experimental data, and we investigate the dried microstructure of the simulated support
The impact of lunar topography on the 21-cm power spectrum for grid-based arrays : Insights for the Dark-ages EXplorer (DEX)
No full textInternational audienceThe Dark Ages (DA) provides a crucial window into the physics of the infant Universe, with the 21-cm signal offering the only direct probe for mapping out the three-dimensional distribution of matter at this epoch. To measure this cosmological signal, the Dark-ages EXplorer (DEX) has been proposed as a compact, grid-based radio array on the lunar farside. The minimal design consists of a 32 32 array of 3-m dipole antennas, operating in the MHz band. A practical challenge on the lunar surface is that the antennas may get displaced from their intended positions due to deployment imprecisions and non-coplanarity arising from local surface undulations. We present, for the first time, an end-to-end simulation pipeline, called SPADE-21cm, that integrates a sky model with a DA 21-cm signal model simulated in the lunar frame and incorporating lunar topography data. We study the effects of both lateral (xy) and vertical (z) offsets on the two-dimensional power spectra across the MHz and MHz spectral windows, with tolerance thresholds derived only for the latter. Our results show that positional offsets bias the power spectrum by per cent relative to the expected 21-cm power spectrum during DA. Lateral offsets within (at 32.5 MHz) keep the fraction of Fourier modes with strong contamination (> 50 per cent of the signal) to less than 1 per cent, whereas vertical height offsets affect a larger fraction. This conclusion holds for the 21-cm window with cMpc over the range of cMpc
Magnetically supramassive and hypermassive compact stars
No full textInternational audienceIt is known that the mass of magnetized relativistic compact star is larger than that of non-magnetized one for the same equation of state and central density, albeit the excess of mass is sizable only if the magnetic fields are strong enough B~10^17-10^18G. Using our recently developed numerical code COCAL, we systematically compute such compact star solutions in equilibrium associated with mixed poloidal and toroidal magnetic fields, and show the magnetically supramassive solutions whose masses exceed by more than 10% of the maximum mass of the static and spherically symmetric solutions. For some extremely strong magnetic field configurations, we also obtain solutions more massive than the maximum mass of the uniformly rotating solutions at the Kepler (mass-shedding) limit, namely magnetically hypermassive solutions
Marine protected areas as living labs ? Lessons learned & future perspectives
No full textInternational audienc
A Mnemonic Matrix Rule for (Split) Octonionic Multiplication and its Extension to the Cayley--Dickson Tower
No full textInternational audienceWe present a compact mnemonic device for computing the product of two (split) octonions written in Cayley--Dickson form q+l p with q,p in H. The rule appears as a simple (R+L) pattern of right-ordered and left-ordered (quaternionic) products inside a 2X2 quaternionic matrix model. The pattern extends verbatim to all algebras in the Cayley--Dickson tower, providing an efficient computational tool in non-associative settings. To our knowledge, this explicit ``(R+L)'' mnemonic does not appear in the classical literature on octonions or composition algebras
Mother Earth and the matriarchal imaginary of environmental law: posthuman advances and biopolitical limits of the rights of nature
No full textInternational audienceAt the turn of the twenty-first century, the figure of Mother Earth has been recognized as a person with autonomous rights in the law of various traditions globally. Ecuador’s 2008 Constitution marked a significant moment when it granted legal personality to the Pachamama. Bolivia followed suit by recognizing the rights of Mother Earth, although not as constitutionally protected fundamental rights. Similarly, New Zealand’s Te Awa Tupua law (2017) enshrined the rights of the Whanganui River as a legal person, embodying the Māori principle Ko au te awa, ko te awa ko au (I am the river and the river is me). These legal reforms attempt to integrate Indigenous worldviews into Western legal frameworks inherited from colonialism. They have been welcomed as a radical overhaul of the anthropocentric paradigm of law. Enshrining the figure of Mother Earth as a subject of law can also be interpreted as a shift toward ecofeminist ideals, where nature’s legal personhood aligns with matriarchal mythologies. However, these evolutions have also been denounced as the biopolitical subjection of nature resulting from the inability of Western law’s rights discourse to encompass the deeper spiritual and physical connections between humans and nonhumans, celebrated in Indigenous cosmologies. Posthuman feminist care ethics might offer a better frame than rights for integrating the specific relation of stewardship encapsulated in Indigenous cosmologies
Numerical Analysis of Test Optimality
No full textIn nonstandard testing environments, researchers often derive ad hoc tests with correct (asymptotic) size, but their optimality properties are typically unknown a priori and difficult to assess. This paper develops a numerical framework for determining whether an ad hoc test is effectively optimal-approximately maximizing a weighted average power criterion for some weights over the alternative and attaining a power envelope generated by a single weighted average power-maximizing test. Our approach uses nested optimization algorithms to approximate the weight function that makes an ad hoc test's weighted average power as close as possible to that of a true weighted average power-maximizing test, and we show the surprising result that the rejection probabilities corresponding to the latter form an approximate power envelope for the former. We provide convergence guarantees, discuss practical implementation and apply the method to the weak-instrument-robust conditional likelihood ratio test and a recently-proposed test for when a nuisance parameter may be on or near its boundary