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Shifting Drivers of Holocene Fire Regimes in Uzbekistan: From Natural Factors to Anthropogenic Impact
No full textInternational audienceIn the context of the current fire intensification associated to climate aridification, this study explores Holocene fire regimes in the foothills of the Pamir-Alai Range (Uzbekistan) through macro-charcoal analysis of sediment cores from Lake Fazilman and the Ogshagil wetland, spanning the past 11000 years. In addition to their novelty, the results reveal distinct fire phases driven by both climatic fluctuations and human activities. During the early Holocene (12000–5000 cal. yr BP), fire activity was primarily climate-driven, with higher frequencies during arid phases. A significant shift occurred around 4000 – 3000 cal. yr BP, with synchronous fire trends at both sites suggesting increased anthropogenic influence linked to agro-pastoral practices of the Oxus Civilization, the Andronovo Cultures and the Handmade Painted Ware Cultures. Fire frequency declined during periods of intensified agricultural practices but increased again in later centuries, likely influenced by shifts in land use and socio-economic dynamics. Over the past 500 years, a rise in fire activity and woody plant combustion, likely influenced by post-medieval pastoral land use and firewood transportation, suggests intensified human impact. This study provides new insights into the interplay between climate, vegetation, human activity and fire in shaping Central Asia's steppe landscapes
Sweat sodium composition and sweat loss estimation through wearable sensors and predictive equations in dry and humid hot conditions
No full textInternational audienceIntroduction: Individualized sweat testing is essential for tailoring hydration and nutrition strategies, as water and sodium losses during exercise vary greatly across athletes. The validity of a wearable sweat sensor (S1, Flowbio) and a handheld analyzer (LAQUAtwin, Horiba Advanced Techno) for measuring sweat sodium concentration ([Na + ]) was tested against flame photometry (FP). Additionally, whole body sweat loss (WBSL) estimated by the S1 and by a sweat rate calculator (SRC) was compared to the scale-based method. Methods: Twenty-three recreationally active participants (11 males, 12 females) completed two sessions in hot and dry (40 °C, 36% rh) and hot and humid (30 °C, 81% rh) controlled environmental conditions on a cycling ergometer (74 ± 12 min, 1.9 ± 0.4 W/kg). Participants were instrumented with two S1 sensors and absorbent patches placed on each upper arm. Sweat was extracted from patches to measure [Na + ] with LAQUAtwin and FP. Nude body mass was measured to the nearest 0.005 kg before and after exercise, with fluid intake monitored to determine WBSL. The influence of the method and the condition on the measure of sweat [Na + ] and WBSL was investigated with linear mixed-effects models. Results: The estimated marginal means of sweat [Na + ] in dry conditions for S1 and LAQUAtwin were equivalent (both 53 mmol/L, p = 0.952) and significantly lower than FP (63 mmol, both -10 mmol, p < 0.001). No significant interaction effects were observed between methods and conditions. For WBSL, the S1 estimation (1.479 kg) was not different than the scale measure (1.432 kg, 0.047, p = 0.624) while the SRC estimation (1.202 kg) was significantly lower than the scale and S1 (both p < 0.001), without interactions effects. Conclusion: S1 offers equivalent and more practical collection of sweat [Na + ] compared to the LAQUAtwin during indoor cycling ergometer exercise. However, measurements from both devices should currently be interpreted Frontiers in Physiology 01 frontiersin.org Bandiera et al. 10.3389/fphys.2025.1717275with caution and not considered equivalent to laboratory-grade analyses. Furthermore, S1 is an adequate tool during indoor cycling ergometer exercise to estimate WBSL when scale measurements are impractical, while SRC was found to underestimate fluid loss.</p
The Developmental Eye Movement Test as a Screening Tool for Reading Difficulties: Insights From a Large-Scale Study in French Schoolchildren
No full textInternational audienceBackground: Efficient visual information processing and cognitive control of saccadic eye movements are critical for reading acquisition in early school. Identifying children at risk of reading difficulties requires reliable assessment tools that can be implemented on a large scale. The Developmental Eye Movement (DEM) test provides an indirect measure of the efficiency of visuo-attentional processes related to eye movements in a simulated reading task. Purpose, Research Design, and Study Sample: To support its use as a screening tool, we conducted a normative validation of the DEM-test in a large, unselected cohort of 1,059 French school-aged children (6–11 years old). Data Collection and Analysis: Age- and grade-specific norms (means and percentile ranks) were established for vertical time, adjusted horizontal time, and error rates. Additionally, we examined its sensitivity to reading difficulties in 46 poor readers and 56 dyslexic children. Results: The results showed a significant developmental progression for all DEM-test indices across age groups, a correlation between DEM-test scores and reading performance (measured by the Alouette test), and significant differences between French, American, and Italian normative data, confirming the influence of language on DEM-test performance. Our findings also revealed a high prevalence of visuo-attentional deficits in poor readers and children with dyslexia. Moreover, the DEM test demonstrated high sensitivity in identifying children at risk of reading difficulties, whether due to a specific reading disorder or a general reading delay. Conclusions: This study provides French-specific normative data for the DEM-test and highlights its potential for large-scale implementation in educational settings. Our findings support using the DEM-test as a quick, non-invasive, and early screening tool to detect reading problems at their onset. By facilitating early identification, this proactive approach could help reduce educational inequalities and guide public health and education policies
Runtime Monitoring for Safety-Critical Vision-based Runway Detection
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The effect of articulatory rehearsal on dual-retrieval processes in semantically related list recall: A comparison between 8- and 10-year-old children and young adults
No full textInternational audienceWhen asked to remember a list of items for later testing, we often repeat earlier items to ourselves as later items are presented. This process, called “rehearsal,” develops during childhood. The present study examined the role of rehearsal in recalling lists of semantically related words and used the dual-retrieval model to pinpoint the retrieval processes modified by rehearsal in children and adults. Thirty-one children (Mage = 8.8 years, SD = 0.5, 12 females and 19 males) and 29 adults (Mage = 20.5 years, SD = 2.7, 23 females and 6 males) performed a complex span task consisting of maintaining words to be recalled later in immediate and delayed tests, while performing a concurrent task. The difficulty of the task was adjusted according to each participant’s abilities. Participants performed the task either silently, which allowed them to use rehearsal, or under articulatory suppression, which reduced rehearsal opportunities. The results showed that, although adults had a higher rate of correct recall, children benefited from rehearsal opportunities for both immediate and delayed correct recall. There were also fewer semantic errors in both age groups when rehearsal could be used. The dual-retrieval model revealed that rehearsal fosters direct access to verbatim memory and reconstruction based on gist memory. Finally, the difference in correct recall and direct access between the two age groups decreased when rehearsal could be used. These findings suggest that, although rehearsal is more effective for adults, children benefit more from it for correct recall and direct access to verbatim traces
Regularization of optimal control problems on stratified domains using additional controls
No full textInternational audienceIn this paper, we investigate a Mayer optimal control problem governed by a dynamics defined regionally. We consider that the state space is stratified into a family of disjoint regions with nonsmooth interfaces, and that in each region, the dynamics is given by a smooth expression. First, it is shown that this problem is equivalent to a new optimal control problem, with additional controls and a (smooth) dynamics defined as a convex combination of the smooth dynamics, along with a mixed control-state constraint. Next, we introduce a family of auxiliary optimal control problems. In these problems, we first regularize the nonsmooth interfaces. In addition, we consider the convex combination of smooth dynamics (only) within a boundary layer. Furthermore, we add a penalization term to the cost function to account for the mixed control-state constraint. Our main result is that solutions to these (smooth) problems converge (up to a subsequence) to a solution of the original one. It is obtained thanks to a new hypothesis related to solutions to the auxiliary problems, which is weaker than the transverse crossing condition of the literature. This technique is implemented numerically on two examples involving non-transverse crossings of interfaces showing its efficiency
Changes in Cooking and Breadmaking Properties of IR 841 Paddy Rice During Storage in West Africa
No full textInternational audienceTemperature and relative humidity can significantly affect quality of paddy rice during storage. Limited studies established the link between storage time, environmental fluctuations, changes in grain and flour physicochemical properties, and culinary performances. In a West African context, IR 841 paddy rice variety was stored under humid-sub-humid (HSH), and dry (DRY) conditions for 12 months. Over 12 months, rice stored under DRY conditions experienced greater environmental fluctuations than rice stored under HSH conditions. Grain water absorption capacity (WAC) increased during storage under DRY conditions, rising from 3.3 ± 0.3 to 3.8 ± 0.3 g/g DM between 0 and 12 months. Flour amylose content and soluble solids remained relatively stable from month 0 to 6 in all conditions, and further under HSH conditions. The observed changes led to improved grain cooking performance after 6 months of storage under DRY conditions. After 12 months, a decrease in rice flour WAC and a peak in viscosity were observed, while mean particle size increased from 42 ± 1 to 67 ± 3 µm under HSH conditions and from 31 ± 3 to 83 ± 3 µm under DRY conditions. Storage time may reduce the breadmaking capacity of rice flour. Overall, environmental fluctuations under DRY conditions strongly affected rice grain and flour properties.</div
Querelles. Penser par la dispute, au Moyen Âge et aujourd'hui
No full textInternational audienceThis work explores the role of disputes in shaping thought. It approaches the quarrel diachronically, treating it both as an object of analysis in medieval studies and as a methodological tool—that is, one of the ways in which research in medieval studies is constructed.Cet ouvrage interroge le rôle des querelles dans la fabrique de la pensée. Il s’agit de considérer la querelle en diachronie, comme objet d’analyse des études médiévales, et comme outil de la médiévistique, c’est-à-dire l’un des modes de construction de la recherche
Introduction. Les sports d'hiver au révélateur de l'Olympisme
No full textInternational audienceCe chapitre introductif propose de tracer minutieusement l’évolution historique des Jeux olympiques d’hiver. Il explore le contexte et les conditions de leur avènement, les dynamiques institutionnelles qui s’y jouent, les mutations de leurs programmes successifs, les méandres géopolitiques dans lesquels ils se meuvent et les résistances auxquels ils font face. En somme, si les Jeux olympiques d’hiver sont un évènement majeur du calendrier sportif international, ils sont tout sauf un « allant de soi » comparé à leurs homologues estivaux