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Real time monitoring of hydrogenotrophic methanogenesis under deep saline aquifers conditions
No full textInternational audienceTo investigate the microbial response to deep underground gas injection, specifically CO2 and H2, a new optically transparent high-pressure reactor was developed to monitor autotrophic microbial growth via in situ and ex situ characterization techniques. The main advantages rely on avoiding any decompression phases during the entire process, thanks to direct optical access. Here, we monitored the growth of the model methanogenic strain Methanothermococcus thermolithotrophicus by applying different H2/CO2 partial pressures at a total pressure of 100 bar, which is representative of the deep underground storage environment. Additionally, we measured the methane production of the strain at the end of the incubation, which resulted in an increase in methane production with increasing CO2 and H2 partial pressures until a certain point. These reactors can be used to investigate deep microbial strains under pressure conditions close to their natural environments, eliminating decompression biases.</p
DFT-guided design of melanin-inspired materials for high-performance organic solar cells
No full textInternational audienceOrganic solar cells (OSCs) have rapidly emerged as a promising alternative to traditional photovoltaic technologies, such as crystalline silicon, due to their potential for low-cost, lightweight, and flexible applications. The development of efficient, non-toxic, and earth-abundant materials has motivated the transition from fullerene-based acceptors to non-fullerene counterparts. While current non-fullerene acceptors offer improved spectral absorption, they still present limitations in terms of absorption bandwidth and exciton dissociation efficiency, which constrain overall device performance. In this work, we designed and computationally evaluated a series of donor and acceptor molecules based on Y6 derivatives and melanin-inspired motifs. Specifically, we investigated the effect of incorporating hydroxyindole-based end groups (EGmel) into the Y6 core structure using density functional theory (DFT). Our findings show that the presence of EGmel broadens optical absorption (red-shift of Δλmax up to ≈ 83.61 nm with gap reduction of up to ΔEgap ≈ −0.28 eV) and enhances electron-donating/acceptance capabilities (up to ΔRD ≈ −0.07 and ΔRA ≈ 0.10), key traits for high-performance OSCs. Furthermore, we assessed a set of melanin-like oligomers as potential donor materials, which showed open-circuit voltage predictions comparable to benchmark donors such as PM6 and D18. These findings underscore the potential of bio-inspired modifications, such as hydroxyindole end groups and indolic donor cores, to improve the performance and sustainability of next-generation organic photovoltaic materials
Absorption mode broadband 2D MS for proteomics and metabolomics
No full textTwo-dimensional mass spectrometry (2D MS) is a method for tandem mass spectrometry that enables the correlation between precursor and fragment ions without the need for ion isolation. On a Fourier transform ion cyclotron resonance mass spectrometer, the phase correction functions for absorption mode data processing were found to be linear in the precursor ion dimension and quadratic in the fragment ion dimension. Absorption mode data processing on limited data sets has previously shown improvements in signal-to-noise ratio and resolving power by a factor of 2. Here, we have expanded absorption mode data processing to 2D mass spectra regardless of size and frequency range. We have applied absorption mode 2D MS to top-down analysis of variously oxidized ubiquitin proteoforms generated by fast photochemical oxidation of proteins (FPOP) and to an extract of ergot alkaloids. We show that absorption mode data processing significantly improves both the signal-to-noise ratio and the resolving power of the 2D mass spectrum compared to standard magnitude mode in terms of sequence coverage in top-down proteomics, as well as the accuracy of precursor-fragment correlation in metabolomics
Terahertz Imaging of Early Stage Thermal Transformations in Oil Shale
No full textInternational audienceThe characterization of oil shales is essential for evaluating their quality and industrial potential. Existing techniques, such as X-ray tomography (XCT), scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM–EDS), infrared (IR) and Raman spectroscopies, and nuclear magnetic resonance (NMR), provide valuable information. However, none of these methods offer millimetric/sub-millimetric-scale resolution with direct sensitivity to simultaneous changes in both water and organic matter within a bulk sample. To address this limitation, terahertz (THz) imaging has previously been applied to oil shales; however, no studies have explored its use under varying temperature conditions of the sample. This is particularly relevant, as heating the samples at low temperatures (<200 °C) can provide new insights into their structural and compositional evolution. Thus, in this work, we acquired THz images after sequential heating an oil shale sample at 40, 150, and 200 °C for 15 h each, in order to monitor its change during thermal evolution. The results revealed, for the first time, changes in the THz images arising from the evaporation of free water, the release of bound water from clays, and transformation of organic matter. These findings were validated and explained by complementary analyses, including X-ray diffraction (XRD), XCT, and Rock-Eval pyrolysis. Furthermore, a first effective absorption and refractive index model was proposed, which enabled the estimation of free and bound water evaporation
A Quasi-Trefftz Method Based on Local Polynomial Impedance Boundary Conditions for Time-Harmonic Wave Propagation Problems
No full textFacing the need to solve time-harmonic wave problems in wide propagation domains, one needs to resort to iterative algorithms, to which classic numerical methods are usually poorly suited. The Trefftz method, based on the use of actual local solutions as basis functions, can then appear as a viable option for this kind of configurations. Thus, we first propose a general formalism allowing to gather different wave problems, so that a general Ultra Weak Variational Formulation can be defined for them at the same time. Yet, as its classic discretisation by plane waves is used to causing independence and accuracy limitations, we suggest to characterise local solutions by an impedance boundary conditions, which is discretised thanks to piecewise polynomial fields. Unfortunately, analytic expressions of such functions are not practically derivable, and we resort to a local numerical method so as to provide approximations: these quasi-solutions are finally chosen as basis functions in the Trefftz formulation, which is then referred as a quasi-Trefftz method. In the end, numerical experiments allow to highlight robust independence, convergence and iterative behaviour of this method, under calibration conditions of the local solver with respect to the polynomial BC discretisation
Le sort de la dépouille mortelle en droit gabonais. De la sacralité à l'oubli juridique
No full textSince the beginning of humanity, man has always wondered about death and his own death. To help him cross this daunting passage and perhaps find another form of life in the afterlife, he gradually established a multitude of funeral rites that have evolved over the centuries under the influence of mentalities, lifestyles, customs and traditions, religions, symbols, and the cultures of peoples. It is also important to emphasize that when the soul leaves the body, only a material remains, so it is necessary to define the legal framework. In this sense, CHEVANDIER said during the preliminary work on the 1887 law on the freedom of funerals that the corpse of an individual is their primary asset. Likewise, to quote Bérengère GLEIZE in her legal analysis of the body as a source of funerary practices, death is, for the lawyer, a major event resulting in the disappearance of legal personality. This death can be defined as a legal fact that can be characterized as a certain term, and which has the effect of removing the quality of being a subject of rights from someone who has now exited the legal scene. Indeed, the consequences are numerous, particularly in civil law, with the dissolution of personal ties and the opening of succession. But if the subject of law no longer exists, death is not nothingness: the body survives this transition from life to death by transforming into a corpse. The law cannot be indifferent to this remnant of the deceased, to this material trace of the departed person.Depuis le début de l'humanité, l'homme s'est toujours interrogé sur la mort et sa mort. Pour l'aider à franchir ce passage redoutable et peut-être retrouver une autre forme de vie dans l'au-delàs, il a institué progressivement une multitude de rites funéraires qui ont évolué à travers les siècles suivant l'influence des mentalités, des modes de vie, des us et coutumes, des religions, des symboles et des cultures des peuples. Aussi, il est important que souligner que lorsque l'âme quitte le corps, il ne reste plus qu'un matériau donc il reste à définir le régime juridique. C'est dans ce sens que CHEVANDIER disait lors des travaux préliminaires à la loi de 1887 sur la liberté des funérailles, que, le cadavre de l'individu est le premier de ses biens. Aussi, pour reprendre Bérengère GLEIZE dans son analyse juridique du corps comme source du funéraire, la mort est, pour le juriste, un fait majeur emportant la disparition de la personnalité juridique. Laquelle mort peut se définir comme un fait juridique pouvant être qualifié de terme certain, et qui a pour effet de retirer la qualité de sujet de droits à l'être désormais sorti de la scène juridique. En effet, les conséquences sont nombreuses, notamment en droit civil, avec la dissolution des liens personnels et l'ouverture de la succession. Mais si le sujet de droit n'existe plus, la mort n'est pas le néant : le corps survit à ce passage de la vie à la mort en se transformant en cadavre. Le droit ne saurait être indifférent à ce reliquat du défunt, à cette trace matérielle de la personne disparue
Modules des dérivations logarithmiques et applications aux diviseurs libres
No full textWe introduce a weighted version of the module of logarithmic derivations of a divisor in weighted projective space, and provide a generalization of Saito's criterion for freeness in terms of weighted multiple eigenschemes (wME-schemes). Freeness of the nonstandard Z-graded module allows one to consider big families of free divisors in affine and standard projective space, i.e. when the module of logarithmic derivations of the divisor is free over the respective coordinate rings. We present a method to identify and construct these new families of free divisors in affine and projective space in any dimension, and give numerous explicit examples
Bridging eco-exposome and one health approaches to address emerging infectious diseases through the EMERG project
No full textInternational audienceAbstract Introduction Emerging or re-emerging infectious diseases (EIDs) are being increasingly reported and represent a significant burden on public health and global economies, as exemplified by COVID-19 pandemic. Context Given the current EID importance at the territory level in Nouvelle-Aquitaine (NA, a French southwestern region), we designed a project to address this risk. The EMERG project and consortium (for “Microbial exposome and EID risks: the benefits of a One Health management of zoonotic influenza-related issues and beyond”) aim at deciphering and anticipating EID risks in NA. EMERG project design EMERG is a transdisciplinary network for evaluating and predicting EID risk and zoonotic potential. EMERG focuses on highly pathogenic avian influenza, zoonotic arboviral infections due to West Nile and Usutu viruses, and the burden of microbial multidrug resistance in NA. Investigative approaches were developed considering the exposome extended to animals, namely the eco-exposome and specifically the microbial eco-exposome. It brings together specialists in human, animal and environmental health. EMERG aim is to provide up-to-date and region-specific data on major EID risks and their determinants in NA, thereby facilitating local management and anticipation of threatening events, epizootics, and epidemics. Implications, limitations, and future directions In addition to addressing the multiscale nature of complex ecosystems driving EIDs, this transdisciplinary project supports informed decision-making for an adapted regional (NA) policy and can be integrated into larger (national, international) public health initiatives. While EMERG has several limitations, it represents a practical implementation of the One Health approach and eco-exposome concept, which is essential for preventing future EID risks. Here, we focused on project design and organization, and presented examples to demonstrate EMERG feasibility throughout a case study
