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Automatic Extraction of Timing Models for WCET Estimation From a High-Level Synthesis Flow
No full textInternational audienceReal-time, domain-specific processors require faithful timing models for WCET analysis. However, existing models are typically hand-crafted from sparse documentation, making them error-prone and difficult to maintain. This work aims to automatically extract WCET timing models from single-issue in-order processor pipelines generated by High-Level Synthesis (HLS). By deriving timing models directly from the SpecHLS intermediate representation, the models are faithful by construction. Experimental results show that our timing-model extraction process generalizes across diverse RISC-V core variants and yields WCET estimates within 0.48% on average of those from a handcrafted model, on the Mälardalen WCET benchmarks
Specific alterations of reactive species interactome markers reflect recovery after mild traumatic brain injury
No full textISTCTInternational audienceRecovery from mild traumatic brain injury (mTBI) is believed to be mediated by the secondary injury response with oxidative stress (OS) playing a central role. Previous studies have largely examined isolated OS markers, yielding inconsistent results. This study adopts a more integrated approach by investigating various components of the reactive species interactome (RSI), a conceptual framework that captures the dynamic interplay of redox components, to better understand the role of OS in the recovery trajectory after mTBI.Twenty-two RSI components were measured in plasma obtained from 65 patients with mTBI in the acute phase (<24 h) and subacute phase (four to six weeks) post-injury and 25 healthy controls (HC). Principal component analysis (PCA) was conducted to identify a subset of RSI markers capable of distinguishing between patients with mTBI and HC. Associations between RSI profiles and functional recovery at six months post-injury, as measured by the Glasgow Outcome Scale Extended, were assessed.Trends (uncorrected P < 0.05) towards increases of hydrogen sulfide (H 2 S) and glutathione and decreases for zinc and peroxynitrite in patients with acute mTBI were observed. Across recovery groups, patients with complete recovery had significantly higher levels of acutely measured catalase (P = 0.002, r rb = 0.45) and lower levels of peroxynitrite (P = 0.003, r rb = -0.43) than patients with incomplete recovery. Subject component scores obtained from the varimax rotated PCA component three (RC3) distinguished mTBI from HC and patients with complete functional recovery from patients with incomplete functional recovery. Strong positive loaders of RC3 included elevated levels of H 2 S, circulating ATP, and malondialdehyde, while loadings of calcium, zinc and peroxynitrite contributed negatively to this component.Our findings highlight a pattern of RSI component alterations associated with recovery following mTBI. These findings underscore the complexity of the redox response after mTBI and highlight potential therapeutic targets, including modulation of H2S, catalase activity and zinc homeostasis
Turning a solar cell into a catalyst: (Ag,Cu)(In,Ga)Se<sub>2</sub> p–n junction enabling ambient dry reforming of methane
No full textInternational audiencePhotocatalysis driven by solar energy offers a sustainable alternative to thermocatalysis for methane valorization, however large-scale deployment remains limited by catalyst efficiency and scalability. Meanwhile, photovoltaic technologies, though highly developed for electricity generation, still face challenges in costly energy storage and underutilized potential in direct solar-to-chemical energy conversion. In this context, CIGS thin-film solar cells emerge as promising candidates for photocatalytic applications due to their strong light absorption, tunable electronic properties, and industrial scalability. In the present work, we use a thin-film CIGS solar cell plates, re-designed as a monolithic photocatalyst, to drive DRM under ambient conditions. A 2 µm ptype (Ag,Cu)(In,Ga)Se2 (ACIGS) absorber deposited on a soda-lime glass/Mo substrate is overcoated with an ntype CdS layer, forming a p-n junction that couples strong light absorption with built-in charge separation. Under irradiation, ACIGS/CdS plates produce > 2 mmol g cat -1 syngas with ≈ 85 % CO selectivity at ambient conditions, without any external electric power or thermal input. Mechanistic evidence indicates deep CH4 dissociation to surface carbon and hydrogen, with subsequent CO2 reduction by surface carbon to CO. The catalytic plates are air-regenerable under light and exhibit notable stability. Turning a solar-cell design into the catalytic junction tackles efficiency and manufacturing hurdles for CH4/CO2 conversion. Because CIGS and CdS processes already exist at industrial scale, this approach provides a practical route to deployable solar chemical hardware; further gains are expected from junction optimization and selective co-catalysts
Domoic acid production by a Pseudo-nitzschia australis strain under zinc and copper exposure
No full textInternational audienceThe diatom species Pseudo-nitzschia australis can produce domoic acid (DA), a neurotoxin- responsible for amnesic shellfish poisoning. Copper (Cu) and zinc (Zn) are essential trace metals for marine phytoplankton, but they can become either limiting or toxic at pico- to subnanomolar ionic concentrations—levels that are can be reached in coastal ecosystems. The effect of exposure to these metals on DA production remains unclear for Cu and is largely unknown for Zn. In this study, we investigated the effects of toxic picomolar concentrations of Cu²⁺ and four non-limiting concentrations of Zn²⁺ on the metabolism and physiology of a toxic P. australis strain isolated from the coastal waters of North Biscay (France). Using principal component analysis, we observed changes in cell populations over time depending on metal exposure. Cu²⁺ toxicity was marked by a 35 % decrease in maximum cell density and a reduction in growth rate (µ₊Cu = 0.55 µₐₓ). DA production was differentially modulated by the two metals: toxic Cu²⁺ levels stimulated DA synthesis (+200 %), while elevated Zn²⁺ bioavailability significantly decreased it (by up to –85 %), including when Zn²⁺ was combined with toxic levels of Cu²⁺ (–65 %). We further discuss DA production by P. australis as a potential protective mechanism against oxidative stress. Additional data on intracellular glutathione (GSH) quotas—an important reactive oxygen species (ROS) scavenger and Cu²⁺ chelator— are presented and linked to Zn2+ bioavailability. GSH cell quotas were significantly correlated with DA production (p < 0.05) further supporting existing links between metal exposition, oxydative stress and DA production. This study suggests that ambient concentrations of Cu²⁺ and Zn²⁺ are critical factors regulating DA production in coastal marine systems
Supramolecular rotaxanes and polyrotaxanes as potential MRI contrast agents: a comprehensive 17O NMR and relaxometric study
No full textInternational audienceRotaxanes and polyrotaxanes made of substituted cyclodextrins (CDs) were designed as potential MRI contrast agents or bimodal optical and MRI probes. After characterization of the threading kinetics and the exact composition of the polyrotaxanes, their MRI properties have been investigated by 1 H relaxometry and 17 O NMR. We demonstrated that the relaxivity of these systems is increasing with increasing size (modified CDs, rotaxanes, and polyrotaxanes). 17 O NMR studies show that the various systems have similar water exchange rates, in the same range as that of Gd-DOTA-monoamide complexes. Interestingly, NMRD data of the smaller systems can be only analyzed by considering both local and global motions via Lipari-Szabo approach, underlining the importance of internal flexibility. On the other hand, the disubsituted rotaxane and the polyrotaxanes are highly rigid and can be characterized with a single rotational correlation time. Their relaxivity is considerably enhanced by a second sphere contribution which is strongly dependent on the structure. It increases from the rotaxane to the mono-and the disubstituted polyrotaxanes, and as expected, it diminishes with decreasing coverage of the axle. The fundamental understanding provided by this comprehensive study will help the design of versatile and more efficient supramolecular interlocked systems such as rotaxanes and polyrotaxanes for MRI applications.</div
Modelling future of airport accessibility: synthetic population and discrete choice model approach to UAM and CCAM demand at Brussels airport
No full textInternational audienceThe emergence of Urban Air Mobility (UAM) and Connected, Cooperative and Automated Mobility (CCAM) offers transformative potential for airport accessibility, promising faster and more personalised connections to major air hubs. However, accurately forecasting the demand for these future transport modes remains a key challenge due to their limited real-world presence and reliance on speculative user preferences. This paper presents a robust and flexible methodology for assessing the future modal split of airport access, integrating both current and emerging mobility options within a discrete choice modelling (DCM) framework. Using a nested logit model calibrated on survey data from over 29,000 Belgian passengers at Brussels Airport, we developed a general-coefficient-based utility specification that enables the integration of hypothetical modes such as UAM and CCAM. This model was then applied to a synthetic population of airport passengers generated via iterative proportional fitting and spatial enrichment. By incorporating realistic operational assumptions for UAM and CCAM, we estimated demand under future scenarios. The results indicate that UAM and CCAM could capture 4.7% and 6.8% of airport access trips respectively, with modal shifts primarily originating from taxi and private car users. This demand modelling framework is assumption-agnostic and adaptable, providing a versatile tool for policy analysis and infrastructure planning as these technologies approach deployment. Future applications will benefit from updated data as these services are piloted, supporting more precise and policy-relevant demand estimations
The role of hydrogen sulfide and trisulfur radical ion in molybdenum transport by hydrothermal fluids: implications for porphyry-epithermal Cu-Au-Mo deposits
No full textInternational audienceKnowledge of the chemical speciation of molybdenum in fluids under hydrothermal conditions is key to understanding the formation of porphyry Cu-Au-Mo deposits, which are the primary economic source of copper, molybdenum and rhenium. However, the chemical identity and thermodynamic stability of aqueous complexes of molybdenum and the role of different ligands on Mo metal transport yet remain inconsistent and incomplete, in particular for sulfur-bearing fluids typical of such environments. We have experimentally studied the role of hydrogen sulfide (H 2 S and HS -) and the trisulfur radical ion (S 3 •-) in the transport of molybdenum by hydrothermal fluids at 300 °C and 500 bar as a function of pH, redox conditions as well as sulfur speciation and concentration. We combined solubility measurements of molybdenite in hydrothermal reactors using fluid quenching or sampling, with in situ synchrotron X-ray absorption spectroscopy experiments and thermodynamic and molecular modeling. Our solubility and spectroscopic dataset is consistent with the formation of the tetrathiomolybdate complex, MoS 4 2-, in reduced, H 2 S/HS --dominated fluids of neutralto-alkaline pH. In contrast, a mixed-ligand complex with three sulfide ions and one trisulfur radical ion, MoS 3 (S 3 ) -, prevails in more oxidized and more acidic fluids at the sulfide-sulfate transition where S 3 •-is far more abundant. In both complexes, Mo is nominally hexavalent and in a first-shell tetrahedral coordination with sulfur atoms. The derived equilibrium constants of the formal solubility reactions (log 10 K):MoS 2(s) + 2 H 2 S 0 (aq) + 0.5 O 2(g) = MoS 4 2-+ 2 H + + H 2 O (liq) and MoS 2(s) + H 2 S 0 (aq) + S 3 •-+ 0.5 O 2(g) = MoS 3 (S 3 ) -+ H 2 O (liq) , at 300 °C and 500 bar are 0.5±0.4 and 14.6±0.4, respectively. The solubility of MoS 2(s) predicted using these constants aligns well with Mo concentrations measured in natural fluid inclusions in quartz that record S-rich fluids from porphyry-epithermal systems. In contrast, other types of Mo complexes invoked so far (molybdates, alkali ion pairs, oxy-chlorides or oxysulfides) are negligible at such conditions. Thus, trisulfur radical ion complexes may be important carriers of Mo in hydrothermal fluids and would require further systematic investigation across a wide range of temperature and pressure.</p
Chapter 13. What are the Consequences for Africa(s) and Issues for the Rest of the World ?
No full textInternational audienceThis chapter offers an analytical structuring of the salient points made by the authors. Firstly, the forum demonstrated the relevance of using three levels of analysis simultaneously to grasp the complexity of the transport and logistics situation in Africa: the macro level (continental, national), the meso level (sectoral, industrial) and the micro level (company and stakeholders). Secondly, the authors have highlighted five key themes for reflection, which are all invitations to push forwardthe research agenda: logistical and digital infrastructures, both of which are deemed insufficient; the expectations of the productive sector with regard to governments and their administrations; the need for deep-rooted African governance, which takes account of African realities and distances itself from models promoted by Western consultants; vigilance with regard to productive and commercial choices that commit to the future of the African economy; and finally, serious training issues which, for the contributors, must give priority to training skills rooted in Africa
Aux origines des écosystèmes entrepreneuriaux : L’entrepreneuriat, modèles d’organisation d’hier à aujourd’hui
No full textInternational audienceCe chapitre propose de revenir sur les origines, l’évolution et l’importance actuelle des écosystèmes entrepreneuriaux en plongeant au cœur de l’évolution des dynamiques entrepreneuriales, s’éloignant progressivement de la figure solitaire de l’entrepreneur pour embrasser la notion plus vaste et intégrative de l’écosystème entrepreneurial
Ni-NbO<sub>x</sub> Bifunctional Catalysts for Selective Hydrodeoxygenation of m-Cresol to Toluene
No full textInternational audienceThe catalytic performances of a series of Ni supported on mesoporous silica (SBA-15) and niobia, as well as Ni-NbOx dispersed on SBA-15 were evaluated for the hydrodeoxygenation (HDO) of m-cresol at 300 °C under atmospheric pressure. Under the reaction conditions, hydrogenation and C-C hydrogenolysis pathways yielding only oxygenated products dominated over the monometallic Ni catalyst. In contrast, the Direct DeOxygenation pathway (DDO) leading to toluene was significantly promoted when Ni was in contact with oxophilic NbOx surface. Tuning the Ni-Nb ratio on silica revealed a remarkable enhancement of the DDO rate constant. Indeed, the kinetic rate constant determined over 5Ni5Nb/SBA was about 11 times higher than that measured on the catalyst containing only the Ni phase. This enhanced performance can be attributed to the formation of well-dispersed Ni-NbOx interfacial sites, where the hydrogenation capability of Ni associate with the oxophilic character of Nb⁵⁺/Nb⁴⁺ species allowing to a more efficient activation of the C-O bonding and promoting the DDO reaction pathway. These results offer valuable insights for the rational design of selective catalysts for the transformation of lignin-derived bio-oils into aromatic hydrocarbons