Publications scientifiques de l'Université de Reims Champagne-Ardenne
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Effect of organic amendments based on date palm residues on barley crop (Hordeum vulgare L.) in an oasian environment: case of the Oued Righ region, Algeria.
No full textInternational audienceThe Saharan soils are known to be poor in organic matter and mineral elements essential to plants. In this context, the field trial has been conducted in the experimental station of the National Institute of Agronomic Research of Algeria (INRAA) of Sidi Mehdi Touggourt in order to improve soil agronomic suitability of the region's palm groves and increase yields. The trial examined the effect of five treatments, including an unamended control and four combinations of organic amendments and/or chemical fertilizer (compost, biochar + compost, biochar + fertilizer and fertilizer alone) on some growth and yield parameters of the barley crop (number of tillers per plant, plant height, and grain yield). A randomized experimental design with three repetitions was used. For all studied parameters, the biochar + fertilizer treatment ranked first compared to the other treatments. In terms of grain yields, it exceeded 51 qt/ha followed by fertilizer treatment (49.9 qt/ha). The compost amendment gave a yield of 36.6 qt/ha. The biochar + compost treatment and the control (cultivated without amendment) were the last with yields of 30.8qt/ha and 27.7 qt/ha, respectively. The statistical study revealed significant to very highly significant differences between treatments depending on the parameters
Le mystère de la maladie des pêcheurs (2020-2021) sénégalais levé [Note politique AWA]
No full text1 : otherIl aura fallu quatre années d'investigations, la mobilisation d'une quarantaine de scientifiques à travers une vingtaine d'équipes de recherche situées dans une quinzaine de laboratoires à travers le monde, pour venir àbout de l'énigme de la maladie mystérieuse qui a sévit au Sénégal en 2020 et 2021 chez les pêcheurs artisans. Cette maladie mystérieuse a touché plus d'un millier de pêcheurs sénégalais, suscitant l'inquiétude et l'attentioninternationale, est une dermatite aiguë. Les mêmes symptômes sont apparus sur des pêcheurs artisans en Guinée en 2023. Une étude menée par un consortium scientifique international (article publié en février 2025)dévoile l'origine de cette maladie : une toxine, la Portimine A, produite par la microalgue marine Vulcanodinium rugosum, jusqu'ici inconnu au Sénégal et dans sa sous-région CSRP. Cette toxine, qui perturbe les cellules de la peau humaine, déclenche une inflammation sévère. Cette étude met en lumière une problématique plus large : l'impact croissant des toxines environnementales sur la santé humaine, dans un contexte du changementglobal, notamment le changement climatique et l'accroissement des flux de transport maritime qui favorisent la prolifération et la redistribution de certains micro-organismes marins, comme les dinoflagellés toxiques.Le trafic maritime favorise la dissémination d'espèces marines d'un écosystème à un autre, notamment par les eaux de ballast. L'épidémie de dermatite associée à la Portimine A illustre les risques imprévisibles queles transformations subies par les écosystèmes marins peuvent entraîner. Elle souligne également l'urgence de surveiller, de manière coordonnée interdisciplinaire à une échelle sous-régionale, les espèces marinesproductrices de toxines, de comprendre leurs mécanismes d'action et d'adaptation, et de développer des solutions pour prévenir et traiter les menaces qui pèsent sur la santé humaine et les écosystèmes marins
Nationalité : de l'opposabilité de l'art. 30-3 c. civ. à des enfants mineurs
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GPA : Vers la reconnaissance d'un « droit à l'enfant » ? À propos d'une parenté de pure intention
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Dividing to Conquer Complexity: A Computational Framework to Study Cell Wall Enzymatic Deconstruction in Highly Deconstructed Samples
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Determination of trade-offs between 2G bioethanol production yields and pretreatment costs for industrially steam exploded woody biomass
No full textInternational audienceLignocellulosic biomass, including wood, can be transformed into bioethanol using steam explosion as pretreatment to improve saccharification and fermentation steps. Pretreatment is however the most expensive part of the process in terms of CAPEX and OPEX and requires to be optimized. In order to evaluate the link between pretreatment efficiency and cost, three contrasted wood species (oak, poplar and spruce) were pretreated with continuous steam explosion at pilot-scale following full factorial designs. Response surfaces obtained were combined with an economic assessment to determine trade-offs aiming at maximizing both fermentable sugars released during the enzymatic hydrolysis step and bioethanol yield during the fermentation step as well as minimizing costs of pretreatment in an industrial context. Results showed that bioethanol yields were highly dependent on wood species and that high severities of pretreatment were not the most relevant to apply. Optimal conditions of pretreatment corresponding to 70 % and 48 % of bioethanol producible from oak and poplar, respectively, were defined. The desirability function that has been modelled thus helps designing adapted pretreatment conditions regarding bioethanol production and process cost
Using the ODD protocol and NetLogo to replicate agent-based models
No full textInternational audienceHighligts: • ODD protocol and NetLogo were used for model replication. • 15 out of 18 agent-based models from different disciplines were successfully replicated. • Model replication can support theory development. • A checklist to support model replication is provided. • Standards such as ODD and quasi-standards such as NetLogo support Good Modelling Practice.Abstract: Replicating existing models and their key results not only adds credibility to the original work, it also allows modellers to start model development from an existing approach rather than from scratch. New theory can then be developed by changing the assumptions or scenarios tested, or by carrying out more in-depth analysis of the model. However, model replication can be challenging if the original model description is incomplete or ambiguous. Here we show that the use of standards can facilitate and speed up replication: the ODD protocol for describing models, and NetLogo, an easy-to-learn but powerful software platform and language for implementing agent-based models. To demonstrate the benefits of this approach, we conducted a replication experiment on 18 agent-based models from different disciplines. The researchers doing the replications had no or little previous experience using ODD and NetLogo. Their task was to rewrite the original model description using ODD, implement the model in NetLogo and try to replicate at least one exemplary main result. They were also asked to produce, if time allowed, some initial new results with the replicated model, and to record the total time spent on the replication exercise. Replication was successful for 15 out of 18 models. The time taken varied between 2 and 12 days, with an average of 5 days. ODD helped to systematically scan the original model description, while NetLogo proved easy and quick to learn, but difficult to debug when implementation problems arose. Although most of the models replicated were relatively simple, we conclude that even for more complex models it can be useful to use ODD and NetLogo for replication, at least for developing a prototype to help decide how to proceed with the replicated model. Overall, the use of both, standard approaches such as ODD and easy to learn but powerful software such as NetLogo, can promote coherence and efficiency within and between different models and modelling communities. Imagine if all modellers spoke ODD and NetLogo as a common language or lingua franca
Extending the functional form of the methane PES in redundant coordinates for high excited vibrational energy levels calculation
No full textInternational audiencePotential energy functions (PES) of AB4-type molecules which are constructed using ten symmetrised combinations of natural four A-Bi valence and six (A-Bi)(A-Bj) interbond angled are referred to as (10S) PESs. This set of coordinates is redundant with respect to the conventional set of 3N-6=9 vibrational degrees of freedom. At high energy ranges, it was found that (10S) PESs permitted improving by factor of five the fit quality of ab initio electronic energies of methane versus standard nine symmetric coordinates (9S) PES representations both in internal, orthogonal or normal-mode coordinates. We extend predictions of vibrational band origins to spectral range above 10000 cm -1 to help future analyses of experimental spectra. Accuracy at high energies is increased without notable deterioration at low-E levels (rms of 0.26 cm -1 ). Based on a comparison between various variants of (10S) PESs we expect that new theoretical band origins should have accuracy not worse than 1-3 cm -1 up to 13400 cm -1 .</div
Polarization of circulating follicular helper T cells correlates with bullous pemphigoid severity
No full textInternational audienceBackground: Follicular helper T (Tfh) cells form a distinct population of T-helper cells with different polarizations (type 1, type 2 and type 17) that regulates humoral responses and may participate in the pathophysiology of B-cell-mediated autoimmune diseases such as bullous pemphigoid (BP), a dermatosis mediated by autoantibodies specific for hemi-desmosomal proteins.Objectives: To evaluate the impact on circulating Tfh cells of super potent topical corticosteroid (TCS) treatment, which is more effective and safer than high doses of oral corticosteroids, and is the recommended first-line treatment of BP. Methods Using flow cytometry, we compared the frequency, polarization and activation of Tfh cells in the blood of patients with BP with age- and sex-matched control participants without BP at baseline and longitudinally, after the initiation of TCS treatmentResults: We found that, at baseline, circulating Tfh cells were more frequent in patients with BP than in participants without BP and exhibited an activated phenotype. We further showed a decrease in type 1 and an increase in type 17 Tfh cells in the blood of patients with BP, which resulted in a higher type 2 + type 17 to type 1 Tfh cell ratio. This ratio correlated positively with disease severity, as measured by the Bullous Pemphigoid Disease Area Index. Remarkably, with TCS treatment, although the frequency of Tfh cells in patients with BP returned to a level similar to that of control participants, the activated phenotype persisted. Interestingly, serum interleukin-21 levels and the Tfh cell subset ratio, similarly to disease activity and serum anti-BP180 and anti-BP230 autoantibodies, decreased with TCS treatment.Conclusions: Overall, our findings suggest the involvement Tfh cell polarization in the pathophysiology of BP and open the door to modulation of Tfh cell activity for treatment purposes