Publications scientifiques de l'Université de Reims Champagne-Ardenne
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Entretien avec Jean-François Thémines par Anne Glaudel. Parcours de recherche et didactique de la géographie
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Benefits of a group-based running session on feelings of energy and fatigue: No augmenting effect of green exercise during the defoliation season
No full textInternational audienceThis randomized controlled trial investigated the impact of a brief session of group-based running on feelings of energy and fatigue, comparing exercise in a local nature reserve versus an outdoor built environment, and a sedentary control condition. Sixty-six physically active university students participated, with 56 providing full data for each time point. Consistent with previous research, participants in both exercise groups reported significantly increased energy and decreased fatigue compared to those in the sedentary control group. However, the type of outdoor environment did not significantly influence the magnitude of improvements. Contrary to expectations, there was no significant difference in energy enhancement or fatigue mitigation between participants who jogged in a local nature reserve versus those who jogged on a cinder track in an urbanized area. The study discusses potential reasons for this, including seasonal variations in forest volatile organic compounds (FVOCs) concentrations, which may impact the psychological effects associated with forest environments. Further research is needed to better understand the complex relationship between exercise, environment, and feelings of energy/feelings of fatigue
Analysis of adobes from vernacular raw earth buildings in the Champagne region (France)
No full textInternational audienceThis study contributes to the understanding of the vernacular raw-earth heritage of the Champagne region in France, where such structures are currently being documented. The research investigates the mineral composition, grain size distribution, and physico-chemical, mechanical, thermal, and hydric properties of seven adobe types derived from soils with varying compositions (predominantly silicate or limestone-based soils). In particular, the influence of calcite content, which spans a wide range from 0 % to 84.9 %, was examined. The results indicate a strong dependency of peak compressive strength on calcite content: higher CaCO₃ levels correspond to lower peak compressive strength. Additionally, the study reveals that the metal oxide content of soils is a critical factor directly associated with mechanical performance. Interestingly, it was observed that historical builders often used weaker adobes for load-bearing purposes and stronger ones for filling, likely without adherence to formal construction standards. Rather than compressive strength, wall design appears to have played a more critical role in structural stability. Regarding thermal properties, calcite content showed minimal influence on diffusivity, specific heat capacity, and thermal conductivity across all adobe samples. Furthermore, all adobes demonstrated excellent to very good moisture regulation performance, with corresponding Moisture Buffer Values varying from 1.65 to 3.09 g/(m².%RH). The findings of this study underscore the potential of traditional raw-earth techniques in rediscovering and evaluating earthen architecture, with implications for promoting sustainable and environmentally friendly contemporary earthen construction and renovation practices
Rootstocks and drought stress impact the composition and functionality of grapevine rhizosphere bacterial microbiota
No full textInternational audienceThe microbiota, a component of the plant holobiont, plays an active role in the response to biotic and abiotic stresses. Nowadays, with recurrent drought and global warming, a growing challenge in viticulture is being addressed by different practices, including the use of adapted rootstocks. However, the relationships between these practices, abiotic stress and the composition and functions of the rhizosphere microbiota remain to be deciphered. This study aimed to unravel the impact of five rootstocks, water management and the combination of both on the rhizosphere bacterial microbiota in grapevines using shotgun metagenomics approach. The results showed that drought impacted the diversity, composition and functionality of the rhizosphere bacterial community. The genera Mycolicibacterium, Mycobacterium and Rhodococcus, and the bacterial functions, including DNA damage repair, fatty acid synthesis, sugar and amino acid transport, oxidative stress reduction, toxin synthesis and detoxification of exogenous compounds were significantly enriched under drought conditions. Rootstocks also significantly affected the rhizosphere bacterial richness but its influence on diversity and functionality compared to water management was weaker. Some taxa and function could be linked to water managements applied. The interaction between rootstocks and water management further influenced the rhizosphere composition, especially under drought conditions, where distinct clustering was observed for specific rootstocks. The results highlight the importance of conducting multifactorial studies to better understand their impact on shaping functional rhizosphere bacterial communities. This study paves the way for future research on beneficial bacterial inoculation and genetic engineering of rootstock to cope with drought stress
How to predict gymnastics' results - A simple method based on the 2022 European Championships
No full textInternational audienceIt is very important for coaches in charge of selection to know the competition level based on the athletes registered, as well as to assess the gymnasts’ capacity to achieve the expected performance. In international artistic gymnastics competitions, access to the all-around (C2), apparatus (C3), and team (C4) finals is determined based on the results of the qualification round (C1). A specialist who competes on only one or two apparatuses may have a chance to win medals on those apparatuses but may also be a disadvantage to the team score. Based on the nominative entries submitted by each competing nation one month prior to the 2022 European Championships held in Munich, we extracted previous individual scores from national and international competitions over a period of six months before the 2022 EC. Individual standard deviations were computed for each competing athlete, and their mean and maximal scores were used as two predictive outcomes. The individual standard deviation on still rings showed a low Q1, median, Q3, and IQR for both junior and senior MAG, while pommel horse exhibited greater variability. Among WAG athletes, those competing in junior and senior vault and floor had lower Q1, median, Q3, and IQR compared to uneven bars and balance beam. When comparing both predictions (mean and maximal values) to the scores obtained in Munich, small differences were observed in terms of random errors. However, a large systematic error indicated a significant overestimation in the maximal prediction, explained by the fact that athletes are not always able to perform at their best. The percentage of gymnasts with a score less than 0.30 points away from the mean prediction ranged from 28.1% (senior floor) to 58.9% (junior still rings) for MAG and from 23.9% (junior balance beam) to 70.7% (senior vault) for WAG athletes. The simple method outlined in this article provides information about the method’s reliability on different apparatuses, as well as insight into the accuracy of score predictions across the apparatuses
La conversation en suspens dans 'Le Dimanche des mères' de Graham Swift
No full textInternational audienceIn the opening scene of 'Mother Sunday' (2016), Graham Swift presents a conversation between a master and a maid, both naked. It is a moment that is suspended in an inner dialogue and a dialogue between bodies and eyes. The power relationship is reversed in the silence that intertwines past and present, and in the affirmation of a protagonist who breaks with her class to become a writer. This conversation on a special day is the expression of a liberation. It is represented in an intermediality with painting, and it takes a political and finally a poetic dimension.Dans la scène inaugurale du 'Dimanche des mères' (2016), Graham Swift présente une conversation entre un maître et une bonne tous deux dénudés. Ce moment est suspendu dans un dialogue intérieur et un dialogue entre les corps et les regards. Le rapport de pouvoir s’inverse dans le silence qui entremêle passé et présent et dans l’affirmation d’une protagoniste qui rompt avec sa classe pour devenir écrivaine. Cette conversation lors d’un journée particulière est l’expression d’une libération. Elle est représentée dans une intermédialité avec la peinture, et elle prend une dimension politique et enfin poétique
Addressing Soil Fertility Challenges in Arid Agriculture: A Two-Year Evaluation of Combined Soil Organic Amendments Under Saline Irrigation
No full textInternational audienceBackground: Soil salinity poses a significant threat to agricultural lands by ad-versely affecting soil properties, crop productivity, and, consequently, global food security. This study evaluated the effects of date palm waste compost (C), applied alone or com-bined with biochar (BCC) or Ramial chipped wood (RCWC), on soil properties and barley yield under arid and saline conditions. Methods: A field experiment was performed in a completely random design with three replications. In addition to the unamended soil (control), treatments with compost (C), biochar + compost (BCC) and Ramial chipped wood + compost (RCWC) were tested. We monitored soil physico-chemical parameters, straw biomass, grain yield, and soluble sugar levels over two crop seasons. Results: Alltreatments enhanced soil fertility. However, the sodium adsorption ratio (SAR) and the cation ratio of soil structural stability (CROSS) increased in soils amended with compost alone in the second crop year. Barley (Hordeum vulgare L.) cultivated in soil amended with C and BCC produced 28% and 37% more dry biomass, respectively, in the second year, while no significant effects were observed in the first year. This may be attributed to the higher availability of nutrient content (N and P) in soils during the second year. In the first year, plants amended with BCC exhibited the highest accumulation of sucrose and fructose,with increases of up to 39% and 66%, respectively. Conclusions: Compost application did not affect barley yield during the first crop year, highlighting limited effects on soil fertility. However, C and BCC improved barley yield in the second year after application. No synergistic effect was observed between biochar, Ramial chipped wood, and compost. Future Perspective: Further studies should focus on the long-term effects of organic soil management, including salinity issues, to support sustainable agriculture in arid regions
On the set of non radiative solutions for the energy critical wave equation
No full textNon radiative solutions of the energy critical non linear wave equation are global solutions that furthermore have vanishing asymptotic energy outside the lightcone at both :for some R > 0. They were shown to play an important role in the analysis of long time dynamics of solutions, in particular regarding the soliton resolution: we refer to the seminal works of Duyckaerts, Kenig and Merle, see \cite{DKM:23} and the references therein.We show that the set of non radiative solutions which are small in the energy space is a manifold whose tangent space at is given by non radiative solutions to the linear equation (described in \cite{CL24}). We also construct nonlinear solutions with an arbitrary prescribed radiation field
Olga Neuwirth: Miroirs déformants
No full textInternational audienceCet article est un portrait de la compositrice autrichienne Olga Neuwirth, à la lumière de ses œuvres récentes et de propos recueillis
Hawai’i is shifting toward regenerative tourism, yet extractive logics persist
No full textInternational audienceMass-tourism destinations are under criticism for intensifying climate risk, biodiversity loss, and social inequities, yet practical alternatives remain scarce. Hawai’i typifies this problem: since the 1970s, the archipelago has relied on a high-volume model that drew 10.4 million visitors in 2019 and continues to generate more than one-fifth of the state’s GDP, while concurrently eroding beaches, exhausting freshwater supplies, and commodifying Native Hawaiian culture. Recognizing these pressures, Hawai’i adopted regenerative tourism as a strategic objective in 2019 to pursue net-positive outcomes, including ecological restoration, cultural revival, and community wealth. However, the application and feasibility of regenerative tourism in mature, mass-market settings remain unclear. To address this gap, this research is a qualitative case study of the Waikīkī beachfront hotel corridor. In-depth, semi-structured interviews were conducted in 2023 with hotel sector stakeholders, state planners, not-for-profit leaders, cultural practitioners, and consultants. Interviews were analyzed with reflexive thematic coding and interpreted through an adapted regenerative tourism analytical framework. Findings reveal uneven but significant movement toward regenerative approaches. Public-sector actors and Kānaka Maoli practitioners articulate multi-capital definitions of wealth and pilot participatory supply-driven innovations. Conversely, for-profit operators retain a demand-driven approach, rebranding experiential add-ons as ‘regenerative’ while maintaining extractive infrastructures. The study thus demonstrates both the promise and the limits of implementing regenerative principles in high-volume contexts, recommending Indigenous co-governance and transdisciplinary learning loops to move beyond branding