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Conserving and regenerating the High Atlas cultural landscapes: gendered perspectives from the local Amazigh communities
No full textInternational audienceLocal communities play a vital role in conserving biocultural diversity; yet their priorities are seldom considered when designing sustainable measures and actions, particularly in remote areas. These processes are frequently developed from urban perspectives, focusing on regional or national scales, and local social dynamics are often overlooked. In this paper, we explore community-based conservation recommendations to develop a strategy for the cultural landscapes of the High Atlas, integrating insights from both local Amazigh voices and academic perspectives. We conducted focus groups with three representative communities in the High Atlas, involving 92 participants. We first documented the environmental changes that both women and men perceived separately. Next, community members provided recommendations for biocultural diversity conservation, which were further discussed among all participants. The participants' perceived changes and the proposed recommendations varied significantly between villages, even over short distances. These variations emerged from each village's primary livelihood and the types of ecosystems on which they depend. Both men and women noted numerous changes in agriculture, pastoralism, and the economy, and suggested actions to address the negative impacts. Women highlighted positive developments in medicinal practices; however, they also pointed out infrastructural deficiencies that hinder human well-being. These discussions served as the grounds for preparing community action plans that guided biocultural conservation action with these populations. Grounding rural development planning, programming, and monitoring in gendered local perceptions and aspirations is crucial for the resilience and adaptation of these landscapes, the people and other non-human living beings inhabiting them
The evolution of drought characteristics in semi-arid Africa over the last four decades
No full textInternational audiencetudy regionSemi-arid Africa, covering six subregions: the Mediterranean (MED), Sahel, North Eastern Africa (NEAF), South Eastern Africa (SEAF), Southern Africa (SAF), and Madagascar (MDG).Study focusWe analyse drought duration, intensity, and severity from 1979 to 2024 across semi-arid Africa. Using Climate Prediction Center (CPC, 0.5°) precipitation and temperature, we compute the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI). Trends are detected with the Mann–Kendall test and Theil–Sen slope estimator. Short-term droughts (3–6 months), strongly influenced by temperature variability, are distinguished from 12-month events driven by cumulative hydrological deficits.New hydrological insightsThree drought episodes emerge: the early 1990s, early 2000s, and the recent period beginning in 2022. Long time-scale indices (SPI-12, SPEI-12) capture the most persistent droughts, whereas short time-scale indices (SPEI-3, SPEI-6) reveal intense temperature-driven episodes. In MED, only 7–25 % of grid cells show significant SPI trends in duration, severity, and intensity, but up to 75 % exhibit drought intensification with SPEI, underscoring strong temperature sensitivity. Across NEAF, SEAF, SAF, and MDG, 25–55 % of pixels show significant increases in drought duration (up to +3 months per decade), severity (+3 units per decade), and intensity (+0.5 units per decade). Parts of the western Sahel and southern Madagascar display decreasing trends. Overall, the study delivers a continent-wide assessment of drought evolution and identifies hotspots where intensifying drought threatens water resources and food security
Drivers of alpine-treeline-ecotone dynamics in the Pyrenees
No full textInternational audienceAimWhile alpine-treeline ecotones are expected to shift upwards and densify under climate warming, observed dynamics vary across mountain ranges. Most studies focus solely on elevational shifts, yet different dimensions may respond to different drivers—limiting our ability to predict ecosystem responses. We examined multiple aspects of treeline ecotone changes (elevational shifts, spatial-pattern changes, and infilling) in the temperate mountain range of the Pyrenees, focusing on the eastern French sector, and uncovered interactions between climate, topography, land use, and lithology at different spatial scales.MethodsWe studied 626 treeline ecotones in the eastern French Pyrenees to examine elevational shifts, spatial-pattern changes, and infilling in relation to climate, land-use, and habitat drivers. Regression and factorial analyses identified key drivers and recurrent environmental combinations affecting treeline ecotone dynamics.ResultsThree environmental clusters revealed contrasting regional dynamics across the eastern French Pyrenees. Western treeline ecotones showed the strongest upward shift, central treeline ecotones exhibited the highest local infilling, and eastern high-elevation treeline ecotones displayed downward shift and diffuse patterns. Overall, local topography influenced fine-scale infilling, while regional land-use and biogeographic contexts controlled broader treeline ecotone elevational shift, highlighting how different drivers operate at multiple spatial scales.ConclusionUnderstanding the effects of climate change requires considering multiple dimensions beyond elevational shifts, as each aspect of treeline ecotone dynamics responds differently to drivers operating at different spatial scales. Management strategies should adapt to multi-scale contexts rather than uniform approaches, particularly where treeline ecotone structure indicates scale-dependent processes
ON A FEKETE-SZEG Ö THEOREM
No full textWe consider again a classical theorem relating capacities and algebraic integers and the question of the simultaneous approximation of different complex numbers by conjugate algebraic integers of degree
The recharge illusion: How seasonal surface loading can hide continuing groundwater resource declines in confined deltaic aquifers
No full textInternational audienceReliable estimates of groundwater recharge are critical for managing water resources and preventing groundwater depletion. However, groundwater recharge estimates can be distorted when loading signals are mistakenly interpreted as signs of groundwater recharge. This study introduces a novel extension to existing frequency-domain methods to quantify loading imprints in groundwater measurements by disentangling superposing signals from Earth, atmospheric, ocean, and river tides, using the K1 tidal constituent to remove the river tide influence. This approach enables the application of frequency-domain methods for calculating the loading efficiency in deltaic groundwater systems, where superposing multiple forcings govern tidal constituents in groundwater heads. Using multi-factor regression deconvolution analysis, surface loading signals are removed from groundwater head time series. Applying this method to groundwater head data from the southern Vietnamese Mekong Delta strongly suggests that the observed seasonal rise in groundwater heads does not reflect recharge. Instead, the apparent upward trend in uncorrected data is attributed to mechanical surface loading from seasonal surface water accumulation linked to expanding aquaculture. The loading-corrected time series show a consistent decline during both dry and rainy seasons, aligning with observed annual depletion rates. This indicates a deficiency of net effective groundwater recharge throughout the year, reflecting unsustainable groundwater exploitation practices. The methods and findings of this study offer a scientific framework for the analysis of multiple superimposed surface loading processes in deltaic aquifer systems, thereby enhancing groundwater recharge assessments in such hydrogeological environments
Impact of conventional and non-conventional processing technologies on phenolic compounds and polysaccharides in strawberry nectar: A comparative study of stability
No full textInternational audienceThermal treatments extend the shelf life of processed products however, they may modify their qualities. This study examines the effects of processing and storage (4 • C during 60 days) on phenolic compounds and cell walls in strawberry nectar. Under microbial inactivation standardization, conventional thermal treatment (TT) was compared to Ohmic Heating (OH), High Pressure Processing (HPP), and Pulsed Electric Field (PEF). HPP resulted in the least colour variation after processing. After storage, colour decreased significantly after PEF, while TT preserved colour most effectively. Immediately after processing HPP-and OH-samples exhibited the highest total phenolic compounds (no reduction and a 4% reduction). However, after 60 days of storage TT better preserved phenolic compounds (a 7% reduction). Proanthocyanidins and anthocyanins degraded over time (a 14% (HPPsamples) and 42% (PEF-samples) reduction respectively). Cell wall components such as neutral sugars and galacturonic acid uniformly degraded after storage. Pectin degree of methylation significantly decreased after storage especially after PEF and HPP treatments which probably failed to achieve complete enzyme inactivation. Storage had a more significant impact on nectar quality attributes than processing
Data-driven discovery of dimensionless numbers and governing laws: A scaling technique for nuclear test facility design
No full textNew designs of water-cooled reactors that include thermal-hydraulics systems undergo safety analysis during the licensing process. For economic reasons and safety concerns, systems are firstly tested on reduced scale test facilities. A proper scaling ensures that dominant thermalhydraulics safety-related phenomena are captured, even though unavoidable scale distortions occur. Some existing scaling methods, based on prior knowledge of the physical phenomena at stake, can quantify such distortions. They are however limited when the phenomena are non-linear and coupled, or even not formalized as an equation. Dimensionless numbers play a central role in scaling techniques as their scale invariant properties help preserve similarities between reactor and test facilities. Building on this principle, this paper proposes a data driven alternative to traditional scaling techniques. From a dataset of physical variables describing the phenomenon of interest, the method identifies a governing law that captures the dominant safety related phenomenon. This governing law is expressed in terms of dimensionless numbers, which are physically meaningful combinations of dimensional variables and are automatically inferred by the algorithm. Based on a clear mathematical formulation, the proposed data driven method combines advanced regression analysis with the constrained optimization of a cross validation based objective function. Two variants are presented: one assuming that the output of the nondimensional governing law is known, and an extension in which this output is estimated. Both variants identify the dominant input dimensionless number as well as the explicit form of the governing law. As a proof of concept, the method is tested on a simulated dataset representative of single-phase natural circulation in a passive heat removal system
Predictions of wheat phenotypic variability by integrating high-throughput phenotyping observations into a crop growth model
No full textInternational audienceAccurate prediction of phenotypes across genotypes and environments is crucial for accelerating crop improvement. Process-based crop growth models (CGMs) can capture complex genotype-by-environment interactions, but their use is limited by labor-intensive genotypic parameter measurements. Here, we developed a faster data assimilation pipeline integrating high-throughput phenotyping (HTP) observations with the Sir-iusQuality wheat model to efficiently estimate key genotypic parameters and predict genotype performance. Using time-series RGB imagery from a ground-based Phenomobile, we assimilated intercepted photosynthetically active radiation (fIPAR), heading date, and final grain yield to jointly assimilated to calibrate twelve genotypic parameters governing phenology, canopy development, light interception, biomass accumulation, and grain filling. Two data assimilation strategies-a Bayesian DREAM (zs) algorithm and a lookup table (LUT) inversion-were compared through both in silico experiment and eight years of multi-environment field trials of nine durum wheat cultivars. The LUT method demonstrated superior computational efficiency, with prediction accuracy comparable to Bayesian inference on real field data. Multi-year field trials showed that two environments (year/site) were sufficient to reliably characterize genotypic parameters and predict performance across environments. By combining time-series HTP data with ecophysiological modeling, our data assimilation pipeline offers breeders a powerful tool for genotype characterization. It streamlines the process of capturing environmental variance and phenotypic stability, reducing time and effort in crop improvement
Seasonal hazard-vulnerability patterns between drought and wildfire in New Caledonia derived from remote sensing products
No full textInternational audienceClimate change is escalating the frequency and intensity of droughts and wildfires globally. In New Caledonia, future intensification is projected, yet the seasonal and directional temporal relationships between vegetation drought and wildfire activity remain insufficiently characterized at the regional scale. This study presents a regional case study combining remote sensing and in-situ datasets spanning 2000-2024, aggregated at monthly and municipal scales, to analyse drought-fire temporal interactions in New Caledonia. The approach quantifies the temporal sequencing of interactions between vegetation condition and burned area occurrence, distinguishing periods when vegetation stress precedes fire activity (fire hazard) from periods when fire occurrence is followed by altered vegetation conditions (post-fire vulnerability and potential feedbacks). Lagged and seasonal correlation analyses were conducted using the Vegetation Health Index (VHI) as a proxy of vegetation drought and the Burned areas Anomaly Index (BAI) to characterize wildfire activity. Results reveal robust and spatially coherent correlations between vegetation drought and burned area extent, highlighting the strong association between VHI and subsequent wildfire activity. Distinct seasonal interaction patterns emerge, with vegetation condition preceding fire activity during the early dry season (August-September), while fire occurrence is followed by modified surface conditions over subsequent months (November-May), consistent with postfire ecosystem vulnerability and feedback mechanism. Marked geographic contrasts are observed, particularly between the west and east coasts. These findings improve understanding of drought-fire temporal linkages in New Caledonia and provide actionable, region-specific insights for seasonally targeted and spatially explicit wildfire risk management
Charles Brosselard et le Tuḥfat al-i‘tibār : sur la paternité des inscriptions arabes de Tlemcen
No full textInternational audienceCharles Brosselard published in the period beteween December 1859 and May 1862 series of epigraphic inscriptions in the African Revue with the title : Arab’s Inscriptions of Tlemcen. However, our recent edition of the Arab manuscript entitled : Tuḥfat al-i‘tibār fīmā wuğida min āṯār bi-madīnat al-ğidār composed by Sī Ḥammū Ban Rūstān, secretary then mufti of the Arab Bureau in Tlemcen in the 1850s, who questioned the attribution of this first work on the commemorative and funeral inscriptions of Tlemcen. This work accomplished at the request of Charles Brosselard, which was based on his publications and reattributed to Sī Ḥammū Ban Rustān and aqually studied the context of its composition and context as well.Charles Brosselard publia entre décembre 1858 et mai 1862 une série d’édition des inscriptions épigraphiques dans la Revue africaine sous le titre : les inscriptions arabes de Tlemcen. Cependant, notre récente édition d’un manuscrit arabe intitulé Tuḥfat al-i‘tibār fīmā wuğida min āṯār bi-madīnat al-ğidār composé par Sī Ḥammū Ban Rūstān, secrétaire puis mufti du Bureau arabe de Tlemcen dans les années 1850, remet en cause l’attribution de ce premier travail sur les inscriptions commémoratives et funéraires de Tlemcen. Ce travail, accompli à la demande de Charles Brosselard dont il fut la base de ses publications, est à réattribuer à Sī Ḥammū Ban Rustān. Sont également étudiés le contexte de composition ainsi que son contenu