Archives ouvertes de Paris-Saclay
Not a member yet
272730 research outputs found
Sort by
Two-point functions in boundary loop models
No full textInternational audienceUsing techniques of conformal bootstrap, we propose analytical expressions for a large class of two-point functions of bulk fields in critical loop models defined on the upper-half plane. Our results include the two-point connectivities in the Fortuin--Kasteleyn random cluster model with both free and wired boundary conditions. We link the continuum expressions to lattice quantities by computing universal ratios of amplitudes for the two-point connectivities, and find excellent agreement with transfer-matrix numerics
Clifford algebras, meson algebras and higher order generalisations
No full textInternational audienceWe analyse the homogeneous parts of Clifford and meson algebras and point out that for the Clifford algebra it is related to fermionic statistics, that is, to fermionic parastatistics of order 1 while for the meson algebra it is related to fermionic parastatistics of order 2. We extend these homogeneous algebras into corresponding algebras related to fermionic parastatistics of all orders. We then define correspondingly higher order generalizations of Clifford and meson algebras
Citation-Driven Multi-View Training for Patent Embeddings: QaECTER and Sophia-Bench
No full textPatent retrieval underpins critical decisions in innovation, examination, and IP strategy, yet progress has been hampered by the absence of benchmarks that reflect the diversity of real world search scenarios. We address this gap with two contributions. First, we introduce Sophiabench, a large-scale patent retrieval benchmark comprising 10,000 queries and 75,000 corpus documents stratified across ten years, eight IPC technology sections, and twelve filing jurisdictions. Unlike prior benchmarks, Sophia-bench tests retrieval using 12 different query types-from structured patent fields to AI-generated summaries-and evaluates results against citation-based ground truth enhanced with a novel domain-relevance metric (InScope). Together, these enable systematic measurement of how well models perform across query types, technology domains, and jurisdictions. Second, we introduce QaECTER, a 344M-parameter embedding model trained on patent citation graphs and multi-view self-alignment. Despite its compact size, QaECTER establishes a new state of the art for patent retrieval. It outperforms the #1 model on the English retrieval text embedding benchmark (RTEB), a model 23× larger, as well as all existing patent specific models across every query type, IPC section, and jurisdiction on Sophia-bench, with gains of up to 7.2% average NDCG@10 over the next-best model. These results are confirmed on an independent external benchmark, where QaECTER surpasses all prior models without requiring task-specific instruction prompts. Both the benchmark and the model are designed for practical deployment in large-scale patent search systems
Expositions hormonales au cours de la vie, asthme actuel et fonction respiratoire des femmes : données de la cohorte CONSTANCES
No full textInternational audienceIntroductionLes disparités entre les sexes en termes de prévalence et de sévérité des pathologies respiratoires chroniques, notamment l’asthme et la BPCO, sont bien établies et ont motivé de nombreuses recherches quant au rôle des hormones sexuelles. Cependant, les résultats demeurent inconsistants. Nous avons exploré les associations entre des indicateurs de l’exposition endogène et exogène aux œstrogènes et la fonction respiratoire, l’asthme actuel et les symptômes respiratoires, chez les femmes de la cohorte Constances. Une modulation par l’Indice de Masse Corporelle (IMC) et le tabac a été recherchée.MéthodesL’analyse a porté sur 61 921 femmes âgées de 18 à 69 ans avec des mesures spirométriques reproductibles à l’inclusion. Les expositions hormonales endogène et exogène ont été approchées par les caractéristiques de la vie reproductive, et par la prise de pilule contraceptive ou d’un traitement hormonal de la ménopause (THM). Les associations ont été étudiées par régression linéaire (fonction respiratoire), logistique (asthme actuel) et binomiale négative (score de symptômes d’asthme), ajustées sur le centre, les données socio-démographiques, l’IMC, les comportements de santé et les comorbidités.RésultatsParmi les femmes incluses, 10,3% déclaraient un asthme actuel, 92% utilisaient une pilule contraceptive, 38% étaient ménopausées dont 40% prenant un THM. Un âge précoce à la ménarche (14ans) était aussi associé à une augmentation du risque d’asthme, et à une diminution de la CVF. Comparées aux femmes nullipares, les femmes ayant eu au moins un enfant avaient un VEMS/CVF plus bas mais une meilleure CVF. Le statut ménopausique n’était pas associé à l’asthme actuel, en revanche, chez les femmes ménopausées, un âge précoce à la ménopause et la ménopause chirurgicale étaient associés à une augmentation des symptômes d’asthme. Par ailleurs, les femmes ménopausées avaient une CVF diminuée et un risque de profil restrictif (CVFLLN) augmenté par rapport aux femmes non ménopausées du même âge. La prise de contraceptifs oraux ou de THM était associée à une augmentation de l’asthme actuel et des symptômes d’asthme quel que soit l’IMC, mais aussi à une meilleure CVF.ConclusionDans ce large échantillon de la population générale, les facteurs reproductifs pouvant refléter une exposition plus importante ou plus longue aux œstrogènes étaient associés à une meilleure CVF, mais à une diminution du VEMS/CVF. Une étude des profils respiratoires dérivés à la fois des données de spirométrie et des symptômes est en cours pour mieux comprendre les résultats observés pour l’asthme
Caractérisation des phénotypes inflammatoires sanguins dans la BronchoPneumopathie Chronique Obstructive et la pré-BPCO en population générale : la cohorte CONSTANCES
No full textInternational audienceIntroductionLes phénotypes inflammatoires basés sur les éosinophiles et les neutrophiles sanguins ont été associés à des expressions cliniques distinctes de l'asthme dans CONSTANCES. Nous avons caractérisé ces phénotypes chez les participants de la cohorte atteints de BronchoPneumopathie Chronique Obstructive (BPCO) ou de pré-BPCO.MéthodesÀ l'inclusion, les participants avec une BPCO ou une pré-BPCO, une numération formule sanguine complète, et sans déclaration d’asthme ont été sélectionnés. À partir d’auto-questionnaires (Symptômes respiratoires : S ; antécédents de bronchite chronique (BC) ou emphysème :À ; Facteur de Risque, tabagisme≥10 paquets-années : FDR) et de spirométrie (Obstruction bronchique (Obs) ; VEMS< 80% préd. sans Obs : PRISm), des sous-groupes cliniques ont été définis : BPCO avérée : Obs+S+A, BPCO probable : Obs+S sans A, BPCO possible : Obs sans S ni A, pré-BPCO clinique et/ou spirométrique (spiro) : FDR+PRISm et/ou S sans A. Les phénotypes paucigranulocytaire (réf. ), neutrophilique (NEU), éosinophilique (EOS) et mixte (M) ont été définis à partir de seuils sanguins de neutrophiles (< /⩾5000 cell/mm3) et d'éosinophiles (< /⩾250cell/mm3). La dyspnée a été évaluée par l’échelle mMRC. Les associations entre phénotypes inflammatoires et caractéristiques cliniques ont été étudiées à l'aide de modèles logistiques ajustés sur l'âge, le sexe, le statut tabagique, le niveau d'éducation, l'indice de défavorisation français, et l'indice de masse corporelle (IMC).RésultatsLes 9197 adultes avaient 48 ans d’âge moyen, 51% étaient des femmes, 40% fumeurs actuels, 17% avaient un IMC≥30kg/m2 ; 2,6%, 4,7% et 13% avaient une BPCO avérée, probable ou possible, et 31,4%, 33,2% et 15% une pré-BPCO clinique, spiro ou les deux. Les phénotypes paucigranulocytaire, neutrophilique (NEU), éosinophilique (EOS) et mixte (M) représentaient 70,5%, 7,6%, 19,4% et 2,5%.Dans toute la population étudiée (BPCO avérée, probable et possible, et pré-BPCO), les phénotypes NEU, EOS et M étaient significativement associés à un risque accru de sifflements avec essoufflement avec des odds-ratio ajustés (aOR) entre 1,30 et 1,68. Le phénotype EOS était associé à un moindre risque d’essoufflement au repos (aOR=0,78 [0,62-0,99]) et de dyspnée (mMRC≥2, aOR=0,84 [0,71-0,99]), et le phénotype NEU était associé à un risque accru (mMRC=1, aOR=1,23 [0,99-1,53]). Les phénotypes EOS et M étaient significativement associés à un risque accru de rhinite allergique actuelle avec des aOR de 1,74 et 1,43. Le phénotype M était aussi associé à un risque accru de réveil par sensation d’oppression thoracique (aOR=1,40 [0,995-1,95]). Le phénotype NEU était associé à un risque accru de BC déclarée (aOR=2,53 [1,42-4,48]).Les analyses des participants avec une BPCO avérée ou probable (n=675) montraient des associations similaires pour le phénotype M et sifflements avec essoufflement (aOR=2,84 [1,15-7,01]), EOS avec mMRC≥2 (aOR=0,64 [0,38-1,09]) et rhinite actuelle (aOR=1,68 [1,04-2,70]), et NEU avec BC (aOR=2,53 [1,21-5,30]).ConclusionChez les participants avec une BPCO ou pré-BPCO, chaque phénotype inflammatoire semble être associé à une expression clinique distincte. La caractérisation de ces phénotypes selon les sous-groupes cliniques est en cours
Formation of gradients of atomic oxygen in nanosecond plasma for plasma-assisted detonation: experimental and numerical study
No full textInternational audienceThis work aims at producing a gradient of atomic oxygen on a scale of 10 cm in a plane-to-plane nanosecond discharge in 150 mbar of air with a varying gap size for applications in combustion and ignition of detonation waves. Local measurements of atomic oxygen density along the discharge span, at varying heights between high-voltage and grounded electrode, are performed with Xe calibrated O-TALIF and validated by 2D numerical modelling. They both show existence of a gradient of atomic density of oxygen along the span. Reduced electric field is measured with two experimental techniques: optical emission spectroscopy by a spectral band intensity ratio of the first negative system and the second positive system of nitrogen, and E-FISH. It is also compared with numerical modelling. All techniques show existence of a gradient of reduced electric field along the span. This distribution of reduced electric field, in combination with the non-uniform energy deposition in the plasma, is shown to explain the measured gradient of density of atomic oxygen
An Automatic Procedure for the Attribution of Extreme Events at the Global Scale: A Proof of Concept for Heat Waves
No full textInternational audienceScientific and media attention to extreme events has increased in recent years due to their severity and the damage they cause. Estimating the contribution of climate change to the probability of occurrence and intensity of these events has become a common practice, thanks to initiatives relying on climate science researchers, who diagnose the return period of the event and the contribution of the anthropogenic forcings in the event properties. These initiatives have succeeded in shedding light on the detection and attribution concept but still rely on the commitment of researchers to deal with an ever-increasing number of events. Here, we propose a proof of concept of an automatic attribution method which, in a few seconds, can attribute a heat wave that has occurred anywhere on the globe and estimate its statistical properties both in the past and in the future, using an existing method based on Bayesian statistics that combines past observations and climate models. Our web application currently covers extreme heat events over a period of 3 days and paves the way to a number of relevant applications, such as (i) enabling public or private organizations to become autonomous, i.e., processing the events they wish without waiting for an academic research investigation; (ii) handling events that have received less attention but have had a major impact, particularly in developing countries; and (iii) climate monitoring of extreme events over a specific region
From Attributional to Consequential LCA: Which Theoretical Framework for Assessing AI’s Environmental Impacts?
No full textThe current hype surrounding generative AI is amplifying the environmental footprint of Information and Communication Technologies (ICT). In response, research into 'green AI' or 'AI for green' has surged. One area of research in this field involves assessing the environmental impacts of AI services. However, studies often lack explicit epistemological and methodological framing, which hinders the quality of their results and sometimes makes them inconsistent. In response to the absence of appropriate framing, the present study draws upon the LCA literature to propose three consistent methodological frameworks, based on their respective epistemological and methodological principles : Attributional LCA, Short-Term Consequential LCA, and Long-Term Consequential LCA. Each approach is examined in terms of its ethical foundations, mathematical logic, and practical implications for defining system boundaries, handling fixed and dynamic costs, and accounting for indirect effects. These approaches are then applied to a common use case for a generative AI service. By clarifying these epistemic and methodological principles, we aim to enhance environmental assessment practices within the sustainable AI literature and improve our understanding of the environmental impacts of this technology
Pliocene contrasted climate conditions in space and over time: A unique pollen dataset from the NW Mediterranean Region for comparison with climate models
No full textInternational audienceA set of 62 Pliocene pollen records and reconstructed climate parameters across the Northwestern Mediterranean Region, together with palaeoclimate simulations from the IPSL earth system model, provide a unique opportunity to study the Pliocene, especially the early Piacenzian Cooling (ePC) and the mid-Piacenzian Warm Period (mPWP). Vegetation reconstructed from pollen records documents strong spatial contrasts in the area. It reveals a retreat of the subtropical broad-leaved evergreen forest to the advantage of Mediterranean sclerophyllous ecosystems.This study is a first attempt to compare observation-based data with model simulations in the Northwestern Mediterranean Region. It reveals substantial discrepancies with encouraging results, pointing out the need to expand the work of data -model comparisons to other regions. The mid-Piacenzian warm period appears to be an interesting past analogue for the ongoing anthropogenic global warming, including its regional impacts. We observe that two areas (Northern Catalonia and the Southern Alps-Liguria) were affected by increased precipitation during brief episodes in the mid-Piacenzian, while the Roussillon-Languedoc-Provence area experienced drier conditions. Such a spatial pattern seems comparable with the present-day context. The significance of ecosystems composed of some Cupressaceae (Cupressus-Juniperus-type) is interpreted partially as subtropical forest, and partially as Mediterranean vegetation. This regional study provides valuable data and interpretations to improve the contribution of past records to such evaluations, and inspires future palaeoclimate simulations with finer resolution
Pre-diagnosis thyroid dysfunction and ovarian cancer risk and survival: a prospective cohort study
No full textInternational audienceAbstract Background Thyroid hormones influence reproductive and metabolic pathways that may affect ovarian cancer development and progression. However, epidemiological evidence is limited and inconsistent. We examined the association between physician-diagnosed thyroid dysfunction and ovarian cancer risk and survival in a large prospective cohort. Methods We included 80,348 women from the E3N cohort who completed at least one biennial questionnaire enquiring about physician-diagnosed thyroid dysfunction (hyperthyroidism or hypothyroidism) between 1992 and 2014. We used Cox regression models with time-varying exposure to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for ovarian cancer incidence through 2018 and, among women diagnosed with ovarian cancer, for overall survival through 2024. Models were adjusted for established ovarian cancer risk or prognostic factors. Results During follow-up (up to 2018), 589 ovarian cancer cases were identified. Overall, pre-diagnostic thyroid dysfunction was not associated with ovarian cancer risk. However, hypothyroidism diagnosed ≥5 years earlier was associated with reduced risk (HR = 0.65, 95% CI = 0.45–0.95) and hyperthyroidism diagnosed ≥5 years earlier and not using levothyroxine was associated with increased risk (HR = 1.70, 95%CI = 1.04-2.78). We found no meaningful association between pre-diagnostic thyroid dysfunction and survival following an ovarian cancer diagnosis. Conclusions Hypothyroidism may be associated with decreased ovarian cancer risk, and hyperthyroidism with increased ovarian cancer risk. Neither hyperthyroidism nor hypothyroidism appeared to affect survival. Whether these associations are causal or whether levothyroxine use plays a role in the development of cancer should be investigated further