HAL Université de Toulouse, et Toulouse INP
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Wideband 1-bit Reconfigurable Circularly Polarized Transmitarrays in Ka-Band
No full textInternational audienceThis study details the design of an active Transmitarray (TA) operating in the Ka-band made of a reconfigurable linear-to-circular-polarization (LP-CP) unit-cell. The unit-cells incorporate a true-time-delay (TTD) polarization conversion mechanism and a stacked patch configuration to achieve wide transmission and axial ratio bandwidths. Each cell integrates a pair of PIN diodes for electronically controllable 180° phase shifts. This is the first demonstration of a wide-band reconfigurable and circularly polarized unitcell in millimeter wave bands, without the use of an external polarizer. A 20 × 20 cells Ka-band circularly polarized TA was designed and fabricated. A random symmetric distribution of rotations applied to the inner patch antenna enhances CP purity and increases the scan range. Measurement results demonstrate a broadside gain of 20.55 dB, with both -3 dB gain bandwidth and 3 dB axial ratio bandwidth exceeding 22%, which surpasses all previous millimeter-wave reconfigurable design. In the case of the 20 × 20 cell array manufactured the scan range extends to ±60 • in both E and H planes, with a maximum scan loss of 4.2 dB and axial ratio values under 2 dB for elevation angles up to ±50°. Additional full wave simulations of a larger 60 × 60 cell array demonstrate a better maximum scan loss of 2.4 dB for elevation angles reaching ±50° , 3.8 dB for an elevation angle of ±60 • and 6 dB for an elevation angle of ±70 • with axial ratio values consistently under 3 dB
Mechanisms, detection, and impact of horizontal gene transfer in plant functional evolution
No full textInternational audienceHorizontal gene transfers (HGTs) have been observed across the tree of life. While their adaptive importance in bacteria is conspicuous, the occurrence of HGTs and their evolutionary significance in eukaryotes has only recently started to be considered. In this review, we explore the extent of HGT in the plant kingdom, indicating the widespread occurrence of microbe-plant HGT and plant-plant HGT. We propose mechanisms that mediate these transfers and detail the methods available to identify and test the robustness of putative HGT using both sequence-based and phylogenomic approaches. Exploring recently sequenced plant genomes across the green lineage has revealed hundreds of such HGTs. We discuss the impact of these transfers on plant adaptation and functional diversification. In the future, expanding the phylogenomic scrutinization of the plant kingdom should reveal the full extent of HGT. In situ sequencing and combinations of synthetic biology and experimental evolution may allow catching ongoing HGT and testing the functional relevance of such events
Editorial perspective: How to minimize the risk of your manuscript being rejected: Perspectives to get your paper published in ‘Crop Protection’
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Les pratiques d’adaptation d’images en dessin en relief chez les transcripteurs-adaptateurs professionnels
No full textInternational audienceThe adaptation of images into tactile graphics is a key issue for improving the accessibility of visual representations for people with visual impairment. This study explores the professional practices of transcribers through a survey conducted in collaboration with the Association des Transcripteurs-Adaptateurs Francophones. The survey aims to characterize the requests and the steps involved in creating tactile graphics. The method is based on the collection of quantitative and qualitative data through an online questionnaire distributed to francophone transcribers. The results reveal several phenomena: insufficient transmission of essential information at the request step, difficulties in analyzing the content of complex images, and a lack of user feedback and proofreading of the adaptations. The study also highlights similarities between tactile graphics adaptation practices and instructional design. Finally, recommendations are proposed to improve practices.L’adaptation d’images en dessins en relief constitue un enjeu important pour l’accessibilité des contenus visuels destinés aux personnes déficientes visuelles. Cette étude explore les pratiques professionnelles des transcripteurs-adaptateurs, à travers une enquête menée en collaboration avec l’Association des Transcripteurs Adaptateurs Francophones. L’enquête vise à caractériser les demandes et étapes de réalisation des adaptations en dessins en relief. La méthode repose sur la collecte de données quantitatives et qualitatives via un questionnaire en ligne diffusé auprès des transcripteurs-adaptateurs professionnels français. Les résultats révèlent plusieurs phénomènes : un déficit de transmission des informations essentielles dans les demandes d’adaptation, des difficultés à analyser le contenu des images complexes, un manque de retours d’utilisation et de relecture des adaptations. L’étude révèle des similarités entre les pratiques d’adaptation d’images en dessin en relief et la démarche d’ingénierie classique de conception de ressources pédagogiques. Enfin, des recommandations sont formulées pour améliorer les pratiques
Les profils métaboliques simulés révèlent des biais dans les méthodes d'enrichissement de voies
No full textInternational audienceIntroduction Initially developed for transcriptomics data, pathway analysis (PA) methods can introduce biases when applied to metabolomics data, especially if input parameters are not chosen with care. This is particularly true for exometabolomics data, where there can be many metabolic steps between the measured exported metabolites in the profile and internal disruptions in the organism. However, evaluating PA methods experimentally is practically impossible when the sample’s “true" metabolic disruption is unknown. Objectives This study aims to show that PA can lead to non-specific enrichment, potentially resulting in false assumptions about the true cause of perturbed metabolic states. Methods Using in silico metabolic modelling, we can create disruptions in metabolic networks. SAMBA, a constraint-based modelling approach, simulates metabolic profiles for entire pathway knockouts, providing both a known disruption site as well as a simulated metabolic profile for PA methods. PA should be able to detect the known disrupted pathway among the significantly enriched pathways for that profile. Results Through network-level statistics, visualisation, and graph-based metrics, we show that even when a given pathway is completely blocked, it may not be significantly enriched when using PA methods with its corresponding simulated metabolic profile. This can be due to various reasons such as the chosen PA method, the initial pathway set definition, or the network’s inherent structure. Conclusion This work highlights how some metabolomics data may not be suited to typical PA methods, and serves as a benchmark for analysing, improving and potentially developing new PA tools
Impact de l'ajustement dynamique de la difficulté du jeu sur le sentiment de flow
No full textInternational audienceDynamic difficulty adjustment (DDA) is a key mechanism for maintaining player engagement in video games. This study compares two types of DDA: one based on player performance, and the other on pupil size, a physiological indicator reflecting arousal and cognitive load. Forty-four participants played two sessions of Tetris using these two adjustment methods. Flow experience was measured using a standardized scale and an innovative temporal graphtracing method. Although no significant difference was observed on average in flow scores, exploratory results show that pupil-based adjustment leads to more frequent changes in game difficulty and a generally higher effective level of challenge, without degrading performance or the players' flow experience. These results highlight the potential of difficulty adjustments based on the player's physiological state and open up new perspectives for affective game design
Association between mycophenolic acid treatment and infection with specific strains of Pneumocystis jirovecii in solid organ transplant recipients in France and Switzerland: a multicentre, retrospective, cross-sectional study
No full textInternational audienceBackground: Pneumocystis pneumonia (PCP) case clusters involving solid organ transplant (SOT) recipients have been reported worldwide. Mycophenolic acid, an immunosuppressant used to prevent rejection in SOT recipients that targets the inosine 5 ′ -monophosphate dehydrogenase (IMPDH) protein, has been hypothesised to exert selective pressure on Pneumocystis jirovecii, with the missense mutation G1020A (Ala261Thr) in the impdh gene a possible marker of such selective pressure. The aim of this study was to test the hypothesis that SOT recipients harbour P jirovecii with mutations in the impdh gene and are infected with specific P jirovecii strains.Methods: In this retrospective, multicentre, cross-sectional study of nationally representative, individual-level data, we included SOT recipients, regardless of the organ transplanted, involved or not in a PCP case cluster, and non-SOT recipients (control group) without mycophenolic acid exposure, diagnosed with PCP from 26 French and one Swiss secondary health-care centres. We included patients aged 18 years or older for whom archival P jirovecii DNA extracts were available in sufficient quantity and quality. P jirovecii specimens were characterised using a multilocus sequence typing method including impdh gene analysis. The primary outcome of this study was the detection of the G1020A (Ala261Thr) mutation in the impdh gene. A multivariable logistic regression was done to assess the relation between this mutation and the following variables retrieved from medical records: age, mycophenolic acid exposure at the time of PCP diagnosis, involvement in a PCP case cluster, PCP prophylaxis, and clinical outcome.Findings: 58 SOT recipients (44 treated with mycophenolic acid) and 59 non-SOT recipients (control group; not treated with mycophenolic acid) diagnosed with PCP between Jan 1, 2001, and Dec 31, 2021, were enrolled. The G1020A (Ala261Thr) mutation was detected in P jirovecii specimens from 40 (68⋅9%) SOT recipients (37 treated with mycophenolic acid) and in none of the P jirovecii specimens from the patients in the control group. The multivariable analysis showed that the allele characterised by the G1020A mutation was associated with mycophenolic acid exposure at the time of PCP diagnosis (adjusted odds ratio 73⋅61 [95% CI 17⋅41-455⋅70]; p<0⋅0001) and involvement in a PCP case cluster (12⋅77 [1⋅58-171⋅90]; p=0⋅029), whereas it was not associated with age, PCP prophylaxis, and clinical deterioration. A second missense mutation, G1020T (Ala261Ser) was identified in P jirovecii specimens from three SOT recipients (two treated with mycophenolic acid). Two specific multilocus genotypes (MLG-31 and MLG-34) of P jirovecii associated with Ala261Thr and Ala261Ser substitutions in IMPDH, respectively, were detected only in SOT recipients (38 patients with MLG-31 and three patients with MLG-34).Interpretation SOT recipients in this study were primarily infected with specific P jirovecii strains with mutations in the impdh gene, which might confer a selective advantage as both the G1020A (Ala261Thr) and G1020T (Ala261Ser) are associated with mycophenolic acid resistance in other fungi. Mycophenolic acid selective pressure might explain the maintenance and circulation of these P jirovecii strains within this patient population, and consequently their potential involvement in PCP case clusters
Agroécologie et biodiversité : construire la recherche en lien avec les territoires: Rencontre entre les chercheurs et les acteurs du territoire en Occitanie ouest
No full textNational audienceL’objectif de la Semaine Écologie, Environnement Biodiversité (SEEB), organisée par le CNRS, est de faire connaitre et reconnaitre l’expertise des laboratoires travaillant sur les socio-écosystèmes, en dialogue avec les Zones Ateliers (ZA) et les Observatoires Hommes Milieux (OHM). L'édition 2025 porte sur les liens entre agroécologie, biodiversité et gestion des ressources face aux changements globaux. Elle met en lumière la co-construction de savoirs et d’outils entre chercheurs et acteurs territoriaux pour accompagner la transition agroécologique. À travers des exemples concrets de collaboration, elle montre comment la recherche peut s’intégrer aux dynamiques locales et participer à l’évolution des pratiques.Lors de la journée organisée en Occitanie à Cazères (31) le 18 mai à la Maison Garonne, une communication a permis d'introduire les deux dispositifs locaux la ZA Pyrénées-Garonne (PYGAR) et l’OHM Pyrénées Haut Vicdessos et Vallée des Gaves, dont les approches agroécologiques contribuent à préserver la biodiversité et les fonctionnalités des écosystèmes, tout en répondant aux enjeux de gestion des ressources (eau, sols…) et à la viabilité économique des exploitations agricoles
Plastics used in agriculture and for food: uses, properties and impacts. Condensed report of the collective scientific assessment
No full textPlastics used in agriculture and for food: uses, properties and impacts. Condensed report of the collecive scientific assessment
Ventriculitis characteristics and outcomes (VELCRO): an international retrospective cohort study
No full textInternational audienceVentriculitis is a dreaded complication of central nervous system infections, which has been scarcely described in the literature. We aimed to present a contemporary picture of ventriculitis, describing its characteristics and outcomes across the spectrum of aetiologies that may lead to ventriculitis. VELCRO is an international retrospective multicentre cohort study conducted at 34 hospitals in six countries. Adult patients fulfilling clinical, microbiological and imaging criteria of ventriculitis between 2010 and 2021 were included. Survival analyses were performed using a multivariable Cox proportional hazards regression model to identify risk factors for 1-year all-cause mortality. Overall, 436 patients with ventriculitis were included: 274 (62.8%) males, median age 58 years [interquartile range 48-68], 68 (15.6%) had diabetes mellitus and 62 (14.2%) were immunocompromised. The most common neuroimaging features of ventriculitis were ependymal enhancement (n=310/436, 71.1%), intraventricular pus (n=286/436, 65.6%) and intraventricular septations (n=85/436, 19.5%). To describe the cohort, patients were divided into three groups: ventriculitis with brain abscess(es) (V-BA, n=181), community-acquired ventriculitis without brain abscess (CA-V, n=88), and healthcare-associated ventriculitis without brain abscess (HCA-V, n=167). Intensive care unit admission was required for 351 patients (80.5%) and the median hospital length of stay was 45 days [26-74]. One-year mortality rate was 33.7% (n=147/436), with a lower rate in patients with V-BA (n=50/181, 27.6%) than in patients with CA-V (n=30/88, 34.1%) and HCA-V (n=67/167, 40.1%). On multivariable analysis, the predictive factors for 1-year mortality were: age > 60 years, immunosuppression, diabetes mellitus, Glasgow Coma Scale score < 13 at presentation, infection involving Enterobacterales or fungi, acute hydrocephalus, cerebral ischemia and intraventricular septations. Staphylococcal ventriculitis was associated with a lower 1-year mortality. Long-term unfavourable outcome (modified Rankin score (mRS) > 2 after 6 months of follow-up) occurred in 43.3% (n=91/210), considering that 26.7% (n=56) had a mRS > 2 before the onset of ventriculitis. Ventriculitis is associated with high mortality and neurological morbidity. Further large prospective studies are needed in this area of research