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Towards Optimising Programs with Sketch-Guided Polyhedral Compilation
No full textInternational audienceWhen programmers use semi-automatic compilers, they typically write optimisation scripts, to guide the compiler towards key optimisations. Instead of writing scripts, it may be preferable to write sketches that focus on the desired structure of the optimised code, without worrying about individual transformations.In this article, we present a new semi-automatic, sketchguided compilation approach. We introduce a sketch language that enables expressing the result of imperative loop transformations and a new polyhedral algorithm capable of generating code constrained by both a sketch and a computation specification.</div
On voting rules satisfying false-name-proofness and participation
No full textWe consider voting rules in settings where voters' identities are difficult to verify.Voters can manipulate the process by casting multiple votes under different identities or abstaining from voting. Immunities to such manipulations are called false-nameproofness and participation, respectively. For the universal domain of (strict) preferences, these properties together imply anonymity and are incompatible with neutrality.For the domain of preferences defined over all subsets of a given set of objects, both of these properties cannot be met by onto and object neutral rules that also satisfy the topsonly criterion. However, when preferences over subsets of objects are restricted to be separable, all these properties can be satisfied. Furthermore, the domain of separable preferences is maximal for these properties.</p
All-sky search for long-duration gravitational-wave transients in the first part of the fourth LIGO-Virgo-KAGRA Observing run
No full textInternational audienceWe present an all-sky search for long-duration gravitational waves (GWs) from the first part of the LIGO-Virgo-KAGRA fourth observing run (O4), called O4a and comprising data taken between 24 May 2023 and 16 January 2024. The GW signals targeted by this search are the so-called "long-duration" (> 1 s) transients expected from a variety of astrophysical processes, including non-axisymmetric deformations in magnetars or eccentric binary coalescences. We make minimal assumptions on the emitted GW waveforms in terms of morphologies and durations. Overall, our search targets signals with durations ~1-1000 s and frequency content in the range 16-2048 Hz. In the absence of significant detections, we report the sensitivity limits of our search in terms of root-sum-square signal amplitude (hrss) of reference waveforms. These limits improve upon the results from the third LIGO-Virgo-KAGRA observing run (O3) by about 30% on average. Moreover, this analysis demonstrates substantial progress in our ability to search for long-duration GW signals owing to enhancements in pipeline detection efficiencies. As detector sensitivities continue to advance and observational runs grow longer, unmodeled long-duration searches will increasingly be able to explore a range of compelling astrophysical scenarios involving neutron stars and black holes
Earliest evidence for the use of desert kite mass-hunting structures in southeastern Jordan during the late pre-pottery neolithic B
No full textInternational audienceDesert kites – large-scale stone structures used for mass game hunting – are among the most extensive prehistoric constructions in the Middle East. Despite their ubiquity, the chronology of their emergence has long remained unresolved. This study presents the earliest direct and robust evidence for the construction and use of desert kites, based on integrated radiocarbon and optically stimulated luminescence (OSL) dating of three kites from a single chain in Jibal al-Khashabiyeh, southeastern Jordan. Excavations focused on the cell-like features around kite enclosures, revealed to be deep pit-traps. Bayesian modeling of 28 dates (10 radiocarbon, 18 OSL) places the highest probabilities of construction of these structures firmly within the Late Pre-Pottery Neolithic B (LPPNB), during the second half of the 8th mill. cal BCE. These findings firmly place kite use as a parallel, indigenous developments in the arid east roughly coinciding with the inhabitation oflarge agro-pastoralist settlements in the Jordanian highlands to the west, reflecting the mosaicked nature of Neolithic developments that characterized the southern Levant already for two millennia. They support a model of indigenous development by highly organized hunter-forager groups inhabiting the arid margins of the southern Levant. The scale, planning, and ecological knowledge embedded in kite architecture produced food in abundance while also supporting novel forms of social organization. The results reposition desert kites as a distinct form of early landscape modification and hunting architecture. The Jibal al-Khashabiyeh data thus anchor a transformative hunting tradition in deep time, offering a new lens on Neolithic innovation beyond the “Fertile Crescent” core
Combination of searches for heavy vector boson resonances in proton-proton collisions at = 13 TeV
No full textInternational audienceA combined statistical analysis of searches for heavy vector boson resonances decaying into pairs of W, Z, or Higgs bosons, as well as into quark pairs (, , , ) or lepton pairs (, ), with e, , , is presented. The results are based on proton-proton collision data at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb, collected by the CMS experiment from 2016 to 2018. No significant deviation from the expectations of the standard model is observed. The results are interpreted in the simplified heavy vector triplet (HVT) framework, setting 95% confidence level upper limits on the production cross sections and coupling strengths to standard model particles or the HVT bosons. The results exclude HVT resonances with masses below 5.5 TeV in a weakly coupled scenario, below 4.8 TeV in a strongly coupled scenario, and up to 2.0 TeV in the case of production via vector boson fusion. The combination provides the most stringent constraints to date on new phenomena predicted by the HVT model
Distribution of antibiotic resistance genes across contrasted tropical agroecosystems in Réunion Island
No full textThis study presents the first exploratory assessment of antibiotic resistance genes (ARGs) and antibiotic residues in agricultural environments on Réunion Island, a French tropical territory in the south-western Indian Ocean. Sixteen samples from diverse matrices (manure, soil, water, and vegetables) across different agroecosystems were analyzed using high-throughput qPCR targeting 332 ARGs and chemical methods targeting 58 antibiotic compounds and trace elements. ARGs were widely detected across all matrices, with highest abundance observed in amended soils and manure. Surprisingly, ARG profiles, in terms of both abundance and average number, were comparable between unamended soils and natural soils. Antibiotic residues were found in only five manure and soil samples, with no clear correlation between the presence of these residues, trace elements and ARG abundance.Organic amendments significantly increased ARG levels in soils and non-metric multidimensional scaling revealed that ARG profiles clustered primarily by matrix type rather than by location. High-risk ARGs were widely prevalent, with 86% detected and 23% ubiquitous across all samples, and their occurrence in water and raw vegetables suggests potential human exposure through the food chain. This study highlights the influence of agricultural practices on environmental antimicrobial resistance in tropical island contexts and supports the need for expanded One Health surveillance integrating the environmental, animal and human compartments.</p
Existence of a solution of the TV Wasserstein gradient flow
No full textOn the flat torus in any dimension we prove existence of a solution to the TV Wasserstein gradient flow equation, only assuming that the initial density is bounded from below and above by strictly positive constants. This solution preserves upper and lower bounds of the densities, and shows a certain decay of the BV norm (of the order of for -- if , otherwise the BV norm is of course bounded -- and of the order of as ). This generalizes a previous result by Carlier and Poon, who only gave a full proof in one dimension of space and did not consider the case .The main tool consists in considering an approximated TV-JKO scheme which artificially imposes a lower bound on the density and allows to find a continuous-in-time solution regular enough to prove that the lower bounds of the initial datum propagates in time, and study on this approximated equation the decay of the BV norm
Natalia Chtempel, Mandelstam à Voronej
No full textОсип Мандельштам в Воронеже. Воспоминания. Фотоальбом. Стихи [Osip Mandelstam à Voronej. Souvenirs. Album photo. Poèmes, édition préface et notes de P. M. Nerler, Moscou, 2008, p. 12-60.Natalia Chtempel, Mandelstam à Voronej, in Ossip, Mandelstam, Cahiers de Voronej. Traduction du russe et préface de Jean-Claude Schneider. Suivi de «L’exil à Voronej», Le Bruit du temps, p. 197-234.En dehors des mémoires de l'épouse d'Ossip Mandelstam, les souvenirs de Natalia Chtempel (ou Stempel) constituent l’une des rares sources qui permette de retracer la vie du poète entre septembre 1936 et mai 1937, à Voronej. Parue pour la première fois dans la revue Europe (2009), cette traduction des souvenirs de Natalia Stempel a été révisée, corrigée et assortie d’une nouvelle annotation
Observer et décrire le monde commun: de l’observation clinque de recherche en psychologie et en psychosociologie
No full textThis article aims to clarify and situate epistemologically a unique approach to clinical observation in psychological research. The author takes stock of more than 15 years of practice, reflection, and teaching of a methodology that is essential to the humanities and social sciences in general, and to psychology in particular: observation. Combining a psychoanalytic approach with a psycho-sociological approach, the clinical research observation developed in this text is part of a clinical research approach linked to the extension of psychoanalysis to groups and institutions. This text aims to provide precise and common methodological guidelines for researchers, but also for psychology practitioners and students of the humanities. The main idea here is to demonstrate that the observer's position is based on the articulation of three levels of observation: self-observation, hetero-observation, and meta-observation. Observation is a complex task that lies at the intersection of the intrapsychic, the intersubjective, and the transubjective.Cet article vise à préciser et à situer épistémologiquement une approche singulière de l’observation clinique de recherche en psychologie. L’auteure y dresse le bilan de plus de 15 années de pratique, de réflexion et d’enseignement d’une méthodologie essentielle aux sciences humaines et sociales en générale et à la psychologie en particulier : l’observation. Faite du métissage entre une approche psychanalytique et une démarche psychosociologique l’observation clinique de recherche telle que developpée dans ce texte se situe dans une demarche clinique de recherche liée aux extension de la psychanalyse aux groupes et aux institutions. Ce texte veut donner des pistes métholdogiques précises et usuelles pour les chercheurs et les chercheuses mais aussi pour les praticiens de la psychologie et encore pour les étudiant.es en sciences humaines. L’idée forte de ici réside dans la démonstration que c’est l’articulation de trois niveaux d’observation qui fonde la posture de l’observateur : l’auto-observation, l’hétéro-observation, la méta-observation. Observer est une tâche complexe qui se loge au nouage entre l’intrapsychique, l’intersubjectif et le transubjectif
Effects of lateral hydrological connectivity on the taxonomic and functional structure of fish communities in Saône river floodplains (France): implications for non‐native species distribution.
No full textInternational audienceLarge alluvial plain rivers provide a complex mosaic of freshwater habitats characterised by a lateral hydrological connectivity (LHC) gradient between the main channel and floodplains. This connectivity plays a key role in structuring aquatic communities, influencing species distribution, diversity, and ecosystem processes. The aims of our study were to assess the effects of the LHC gradient on both fish taxonomic and functional diversity, and to characterise the effects of this connectivity on the distribution of non‐native species. Community data were gathered through electrofishing at five sites in the main channel of the Saône River (France), and in four permanently (parapotamic) and four occasionally (plesiopotamic) connected oxbows. Functional diversity was investigated using a trait‐based approach as surrogates of ecosystem processes. A total of 28 fish species were identified, including 14 non‐native species. Our results show that main channel and plesiopotamic oxbows exhibited distinct compositional and structural patterns of fish communities, while parapotamic oxbows displayed an intermediate composition and community structure. Taxonomic and functional diversity decreased along the lateral continuum from the main channel to plesiopotamic waterbodies. In contrast, while non‐native species richness was similar between the main channel and floodplains, their densities were higher in floodplain oxbows. These findings highlight the prominent role of hydrological connectivity in sustaining both taxonomic and functional diversity in riverine ecosystems. Fish community variations between habitats may be explained by physical changes resulting from reduced connectivity, primarily characterised by a loss of depth and surface area, which in turn affect a broad spectrum of abiotic and biotic factors. High densities of non‐native species in lentic environments like oxbows can be attributed to specific abiotic conditions (e.g., hypoxia, rapid temperature fluctuations and eutrophication) and the greater tolerance and plasticity of non‐native species compared to native species. Additionally, the absence of predators reduces top‐down control and intensifies competition with native species for resources. Conservation and management strategies should prioritise preserving and restoring connectivity to support native fish communities, limit the dominance of non‐native species, and maintain the ecological integrity of freshwater ecosystems