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The global spectrum of tree crown architecture
Get PDFTrees can differ enormously in their crown architectural traits, such as the scaling relationships between tree height, crown width and stem diameter. Yet despite the importance of crown architecture in shaping the structure and function of terrestrial ecosystems, we lack a complete picture of what drives this incredible diversity in crown shapes. Using data from 374,888 globally distributed trees, we explore how climate, disturbance, competition, functional traits, and evolutionary history constrain the height and crown width scaling relationships of 1914 tree species. We find that variation in height–diameter scaling relationships is primarily controlled by water availability and light competition. Conversely, crown width is predominantly shaped by exposure to wind and fire, while also covarying with functional traits related to mechanical stability and photosynthesis. Additionally, we identify several plant lineages with highly distinctive stem and crown forms, such as the exceedingly slender dipterocarps of Southeast Asia, or the extremely wide crowns of legume trees in African savannas. Our study charts the global spectrum of tree crown architecture and pinpoints the processes that shape the 3D structure of woody ecosystems
Scaling up the assessment of logging's impact on forest structure in Central Africa using field and UAV data
Get PDFA third of the forest area in Central Africa has been granted to logging companies. Logging is highly selective in the region, with an average of 0.7–4.0 trees harvested per ha, but its direct impact on forest structure and the spatial variation of this impact remain understudied. Here, we investigated the direct impact of logging on forest structure, we related this impact to logging intensity and canopy opening. We compiled unique datasets collecting field measurements and aerial observations in four FSC certified concessions. Our data includes pre- and post-logging inventory of forest plots covering 38 ha, records of over 6000 harvested trees, and drone RGB images covering over 6000 ha. In average, logging activities reduced forest above-ground biomass by 8.8%, stem density by 6.5%, basal-area by 8.5% and canopy cover by 4.4%. Strong relationships were found between the reduction in biomass, stem density, or basal area with logging intensity, canopy opening and the number and volume of harvested trees (relative root mean squared error (rRMSE) between 0.128 and 0.164). Additionally, we demonstrated that canopy opening can be a good indicator to monitor and upscale logging intensity (rRMSE between 0.0005 and 0.0022). This study is the first covering extensive inventory plots and uninhabited aerial vehicle images before and after logging in different locations in Central Africa, providing a valuable reference to evaluate the impact of logging on forest structure. It demonstrates how canopy opening can be used to estimate measurements usually collected in the field and provides to the remote sensing community a unique dataset that will help improving monitoring systems (Dupuis et al 2024 (available at: https://hdl.handle.net/2268/323683)). These findings also have significant implications to control and manage logging activities, especially for certification standards, forest administrations, and European regulations
MITD1 is a brain-specific interferon-inducible factor that inhibits flavivirus replication
Get PDFWest Nile virus (WNV) and Usutu virus (USUV) are closely related mosquito-borne neurotropic flaviviruses that share common transmission cycle and can infect humans. However, while human infections by WNV are widespread, infections by USUV are comparatively less frequent, less severe, and currently limited to Africa and Europe. To identify human host factors that contribute to the pathogenic signatures of these two flaviviruses, we carried out an arrayed expression screen of over 1,300 interferon-stimulated genes (ISGs). Several ISGs known to target flaviviruses, including IFI6, SHFL, and RTP4 were among the strongest hits. Interestingly, we also found MITD1, an ISG with no previously reported antiviral activity, among the strongest hits. We demonstrated that the antiviral activity of MITD1 was not limited to USUV and WNV, since it also inhibited Zika and dengue virus replication. We found MITD1 to interfere with viral RNA replication by sequestering specific endosomal sorting complexes required for transport-III (ESCRT-III) proteins involved in the formation of viral replication factories. MITD1 expression was not increased by type I interferon (IFN-I) in most human cells and mouse tissues that we examined, although WNV and USUV replication was strongly inhibited by IFN-I. Strikingly, MITD1 was induced in the brain of USUV-infected mice and importantly, in human monocyte-derived microglia. Using human microglial-like cells, we confirmed that MITD1 is an essential mediator of the anti-flavivirus activity of IFN-I in these cells. We conclude that MITD1 plays a key role in the cellular defenses against neurotropic flaviviruses
Capacity-lift service model Service. 3: Self-paced training on the core capacities to manage R&I project for impacts
Get PDFOptimizing nitrogen use efficiency in European livestock systems: From feed to plant growth
No full textNitrogen (N) is a crucial nutrient for agriculture. Its unlimited provision by the Haber-Bosch process has led to high N surplus in agriculture, causing severe negative environmental externalities. The reduction of N losses in livestock systems and consequent enhancement of their nitrogen use efficiency (NUE) represents a key lever to substantially reduce the N surplus to meet European environmental policy targets. This review evaluates the potentials to improve the NUE of European cattle and pig livestock systems from feed to plant N use along the whole livestock system cascade. It discusses options to improve feed NUE and the current measures to reduce N losses at housing, manure storage and application as well as crop N recovery. The findings are synthesized at the overall livestock system level using exemplary case-study farms from selected European regions, to highlight potentials for livestock system NUE improvements in the context of the current and future European legislations. All case-study farms have already implemented measures for N loss mitigation, and their livestock system NUE reaches values between 55 % and 75 %. With the implementation of additional measures such as liquid manure acidification, low emission technologies and best field management, livestock system NUE can reach values between 75 % and 85 %. In order to achieve such high livestock system NUE and meet environmental goals, a scaled implementation of best available technologies is essential, and has to go hand in hand with a legislative harmonization and a targeted development of additional reduction measures and auxiliary tools for farmers
The invaded range of the tree fern Sphaeropteris cooperi is predicted to shrink in two southern hemisphere biodiversity hotspots
Get PDFBiological invasions are increasing globally, with species demonstrating differing responses to climate change in their native and invaded ranges. Investigating how alien species respond to climate change is important for planning management interventions. This study considered how the distribution of Sphaeropteris cooperi (Hook. ex F.Muell.) R.M.Tryon, a widely cultivated invasive tree fern with a broad climatic tolerance, could alter under climate change in two invaded southern hemisphere biodiversity hotspots: South Africa's Garden Route and La Réunion Island, Mascarene Archipelago. To determine the distributional changes of S. cooperi under future climate change scenarios, its niche dynamics were assessed in its native range (Australia) and two invaded southern hemisphere ranges using Schoener's statistic for niche overlap and principal component analyses. An ensemble modelling approach was used to predict the potential distribution of S. cooperi under future (2041–2070 and 2071–2100) carbon emission scenarios (SSP1-2.6 and SSP 5–8.5) using five global climate models. The results suggest that S. cooperi demonstrates some climatic niche overlap (17.6 %) between the Garden Route and its native range (Australia), but less overlap (3.7 %) was found between La Réunion Island and Australia. On La Réunion Island, little niche overlap together with niche expansion suggests that S. cooperi occupies niches not occupied in its native range, and that niche conservatism does not hold true for this location. Thus, under current climatic conditions, future spread may be anticipated in both the Garden Route and La Réunion Island. However, climatic conditions are shifting making it important to consider climate change when predicting how the range of this invader may change in the future. Species distribution models revealed that for both biodiversity hotspots, regardless of climatic scenario or the time frame considered, the range of S. cooperi is predicted to shrink, although the degree of decline is expected to vary with time and climate scenario
L'espace au service de la santé
Get PDFL'exploration spatiale dépasse la simple conquête de nouveaux territoires, elle représente aussi un levier majeur d'innovation dans le domaine médical. L'environnement spatial, caractérisé par la microgravité, les radiations et l'isolement, impose des défis physiologiques, psychologiques et biologiques aux astronautes. Pour préserver leur santé, des solutions technologiques avancées sont développées, allant de la télémédecine aux systèmes de surveillance physiologique ou plus généralement à des systèmes d'assistance pour l'aide au diagnostic et aux soins. Les défis que posent les missions spatiales permettent ainsi d'accélérer des innovations pour répondre à la fois aux besoins spatiaux et à des applications sur Terre, notamment pour le suivi médical en environnements isolés ou extrêmes où l'accès aux soins est limité. Par ailleurs, les technologies ou données issues du spatial, notamment grâce aux satellites d'observation, de communication ou aux services de géolocalisation, peuvent jouer un rôle crucial en santé publique. Elles permettent de contribuer à la surveillance sanitaire, de détecter des risques environnementaux affectant la santé humaine et d'améliorer l'accès aux soins à distance, notamment dans les zones reculées. En France, le Centre national d'études spatiales (CNES) et l'Institut de médecine et de physiologie spatiales (MEDES) sont des acteurs clés dans ces avancées. En collaboration avec les communautés scientifiques et industrielles, ils participent activement à la recherche et au développement de nouvelles technologies médicales adaptées aux défis de l'exploration spatiale et transposables aux besoins terrestres. Grâce à ces efforts, l'espace devient un laboratoire d'innovation médicale, dont les retombées bénéficient aussi bien aux astronautes qu'aux populations terrestres confrontées à des défis similaires en matière de santé
Rapport de mission Santeff - Atelier d'accompagnement à la co-analyse des enquêtes de perception de la santé du territoire - Période du 18 au 23 septembre 2024
Get PDFComparative minerals and vitamins composition of bactrian (Camelus bactrianus) and dromedary (Camelus dromedarius) meat
Get PDFOne humped dromedary (Camelus dromedarius) and two humped Bactrian (Camelus bactrianus) camels are different species, but with close biology allowing fertile crossbreeding. Several publications have explored the differences in meat composition (amino acids and fat). This study was designed to compare the mineral and vitamin composition of dromedary and Bactrian camel meat. Six muscle samples were collected from nine Bactrians, from Kazakhstan, and ten dromedaries from the Sultanate of Oman. Minerals were determined using an Atomic Absorption Spectrophotometer and the vitamins were investigated by high-performance liquid chromatography. Differences in mineral and vitamin composition were investigated using discriminant analysis. Calcium, potassium, phosphorus, and zinc were the most important discriminating minerals allowing for 71.3% of well-classed animals. A close percentage (74.4%) was observed with the combination of vitamins B1, B12, and C. Dromedary meat contained significantly more calcium, zinc, vitamin B1, and B6 than Bactrian. However, the inter-species difference appeared to be less important than the inter-muscle differences, with a more specific composition of the Longissimus thoracis, compared to other muscles, especially its low mineral concentration and relatively higher vitamin E. Bactrian and dromedary camels, despite their relative genetic proximity, live in two different ecosystems, which may explain the differences in their meat composition