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A multiscale lattice Boltzmann model for simulating Stokes to pre-Darcy flow
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Changes in phenology mediate vertebrate population responses to temperature globally
No full textInternational audiencePhenotypic responses to climate affect individual fitness, but the extent to which this translates into effects on population dynamics remains poorly understood. We assemble 213 time series on phenotypes and population sizes of wild vertebrates globally and match them with local climate data. Our meta-analysis shows that morphological traits are mostly climate insensitive. However, phenology is earlier in warmer-than-average years, which contributes positively to population growth in most species. At lower latitudes, temperature has weaker effects on phenology but stronger direct negative effects on population growth, likely because these populations are less capable of tracking climate via plasticity. Variation in the phenology-mediated effect of temperature on population growth cannot be explained by latitude, generation time, migratory mode, or diet. This suggests that simple relationships between species characteristics and population responses to warming may not occur in nature. Instead, we may need to embrace ecological complexity by considering local-scale predictors that capture intra-specific variation
Airbnb and Returns to Housing Capital: Evidence on Inequality from Administrative Data
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Tungsten-induced atypical multilayer growth in a new amorphous Al-Ti-(W) thin films: A key to improve corrosion resistance in saline environment
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Multi‐Method Geophysical Surveys Between and Around the Kerlescan and the Manio Megalithic Alignments in Carnac (Morbihan, France)
No full textInternational audienceThe Carnac alignments in Morbihan (France) are among the most famous Neolithic sites of the world. Paradoxically, they have benefited little from a thorough renewal of archaeological data over the past century. There are many reasons for this, but it is mainly because the site has been regarded more as a monument to visit and protect than as an archaeological site to be explored through excavation. The largest archaeological intervention in the menhir alignments had been the excavation ‘Manio 2’ burial mound by Zacharie Le Rouzic and the Péquart in 1922. Research and conservation efforts slowed down after Zacharie Le Rouzic died in 1939, except for the excavations carried out on the Kerlescan site between 1940 and 1942 during the German occupation by Werner Hülle. After World War II, preserving the site became the priority. Intense research into megalithism in the region came to a halt and shifted to other areas of Brittany and did not include the Carnac alignments. However, several grey areas remain, particularly regarding the shape and location of the settlements associated with the Carnac alignments, such as ditches, fences, postholes and hearths. These structures were obviously more discreet and undoubtedly accompanied the menhir alignments and burial mounds. Discoveries made during preventive excavations around Carnac have revealed a high density of cooking stones and monoliths, which were undetectable during surface surveys because of their burial. Therefore, the possibility of discovering such structures using geophysical methods is a significant research challenge that offers considerable potential for expanding our knowledge. The objective of the 2024 geophysical surveys was to evaluate the effectiveness of modern geophysical methods in detecting underground structures related to the Carnac alignments. These surveys built on the expertise developed through the ANR MONUMEN program in central‐western France. This article summarizes the initial results of the geophysical surveys of the Carnac alignments
Predation Risk Does Not Delay Breeding but Reduces Nest Survival in High‐Arctic Shorebirds
No full textInternational audienceUnderstanding predator-prey interactions is crucial for correctly answering many fundamental research questions, given their behavioural, ecological and evolutionary consequences. Such interactions can result in the direct consumption of the prey, but also in behavioural responses such as changes in breeding phenology. Space use of predators and the associated predation risk is a dynamic process, resulting in constant adjustments by the prey at different spatiotemporal scales. In the Arctic, predator-prey interactions are expected to change owing to the ongoing climate change and the associated shifts in ecosystem composition. However, most studies investigating the impact of predation on ground-nesting birds use data from artificial nests that lack the behavioural component of incubation. Consequently, studies investigating the impact of predation risk on real nests are needed, especially in arctic ecosystems of relatively low productivity. Using nest data collected over 3 years in Northeast Greenland, we investigated how spatial variations in predation risk by arctic foxes (Vulpes lagopus) impacted daily nest survival rates and start of incubation dates of two sympatric species of sandpipers: the sanderling (Calidris alba) and the dunlin (Calidris alpina arctica). Fox spatial activity was estimated by calculating their Autocorrelated kernel Utilisation Distributions based on fine-scale GPS data. We found that both sandpiper species had higher daily nest survival rates in areas of low fox activity. However, sandpipers initiated their nests earlier in areas of high fox activity. Together, these results show that predation risk does not delay the breeding phenology of high-Arctic sandpipers, and that predation risk clearly translates into lower nest survival, as often claimed by previous studies using artificial nests
Comparative Toxicity of Bordeaux Mixture by Ingestion and Cuticular Contact Under Climate Change Conditions on <i>Trichogramma cordubensis</i>
No full textInternational audienceIn the face of environmental contamination to copper, mainly resulting from frequent copper-based fungicide applications, it is crucial to understand the side effects of these pesticides on non-target organisms to favor sustainable pest management. Pest natural enemies are indeed severely exposed to copper fungicides through external physical contact and by ingestion. In this study, we assessed the effects of Bordeaux mixture applications on the longevity of the biological control agent Trichogramma cordubensis (Vargas and Cabello, 1985) (Hymenoptera: Trichogrammatidae). The first set of experiments aimed to evaluate the effective doses of Bordeaux mixture contamination by using eight doses from 0 g.L -1 to 160 g.L -1 . When ingesting honey contaminated with Bordeaux mixture the longevity of T. cordubensis was strongly reduced. Conversely, cuticular contact with Bordeaux mixture, without ingestion, had no effect on T. cordubensis longevity. The second set of experiments examined how the effects of Bordeaux mixture on T. cordubensis longevity were modulated by global warming conditions, under two fluctuating climatic regimes simulating current and future conditions in Burgundy, France. These experiments used effective doses obtained after the first experiments. Similarly to the first experiments, Bordeaux mixture ingestion led to strongly reduced longevity, whereas cuticular contact had no effects on T. cordubensis longevity. Warming conditions reduced T. cordubensis longevity by 36% after both ingestion and cuticular contact with Bordeaux mixture, with no statistical interaction with Bordeaux mixture. Ingesting Bordeaux mixture was considered to be slightly to moderately harmful, significantly reducing the longevity from 40% to 81% with increasing concentrations, whereas cuticular contact with Bordeaux mixture was harmless to T. cordubensis. This study sheds new light on the side effects of metal-based fungicides on natural enemies and their subsequent effects on biocontrol programs. It suggests that increasing temperatures should have deleterious effects on Trichogramma species, regardless of fungicide contamination by Bordeaux mixture
2. Mise en images : L’iconographie de la révolution aux États-Unis depuis le XVIIIe siècle
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Publicité télévisée des enseignes de distribution : « le loup plaidant contre le renard »
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Effect of recycled waste cardboard chips on the physico-thermal-hygric properties of hemp-lime biocomposites
No full textInternational audienceBuildings are major contributors to global energy consumption and environmental impacts, highlighting the critical need for sustainable and energy-efficient insulation materials. Biocomposites incorporating recycled cardboard have emerged as promising solutions for such applications; however, their production methods are often labor-intensive, energy-demanding, and time-consuming. To address these limitations, the present study explores the feasibility of using recycled waste cardboard chips (RWCC) as a partial or complete replacement for conventional hemp shives in hemp-lime biocomposites. A simplified, low-energy, and rapid processing methodology was developed in which untreated RWCC, cut directly from post-consumer cardboard, were incorporated into hemp-lime matrices without any pre-treatment. The RWCC were mixed using a rapid blending procedure and lightly compacted, thereby eliminating the need for grinding, crushing, soaking, defibrating, extended compaction, or thermal curing. Substitution ratios ranging from 0 to 100 wt% were investigated to assess physical, thermal, and hygric properties. The resulting biocomposites exhibited low densities (514-682 kg/m 3 ) and high porosities (68.7-75.5%), leading to low thermal conductivity (0.0775-0.0919 W/(m⋅K)), high heat capacity (972-1036 J/(kg⋅K)), low thermal diffusivity (1.25-1.51 × 10 -7 m 2 /s), and low thermal effusivity (200-248 J/(m 2 ⋅K⋅s 1/2 )), thereby enhancing both insulation performance and thermal inertia. Adequate vapor permeability (1.24-2.12 × 10 -11 kg/(m⋅s⋅Pa)) and moisture buffer capacity (0.66-1.59 g/(m 2 ⋅%RH)) were also observed, supporting healthy indoor environments. Overall, the results demonstrate the feasibility of valorizing untreated RWCC in hemp-lime matrices, achieving properties comparable to those of established bio-based insulation materials while significantly reducing processing intensity