eKhSACIR інституційному репозитарії Харківської державної академії культури
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Du concept d'utilité commune
No full textLe principe d'utilité commune est considéré comme fondationnel. Il s'agit de proposer une première définition de l’utilité commune à partir des définitions d’utilité, d’utilité collective et de bien commun. Son intérêt serait de rendre possible (conformément à l'article premier de la déclaration des droits de l'homme et du citoyen) une distinction sociale en optimisant une fonction d’utilité commune
Barriers and Strategies to Boost Soil Carbon Sequestration in Agriculture
No full textInternational audienceThe Paris Agreement calls for limiting global warming below 2°C. The “4 per 1,000 Initiative: Soils for food security and climate” was launched in 2015 to increase soil organic carbon sequestration with three objectives: mitigation of climate change, adaptation to climate change and improved food security. One of the challenges of the Initiative relates to its feasibility in contrasted biophysical, social and economic environments, questioning the adoption rate of required new practices. We conducted participatory multi-stakeholder workshops in France and Senegal to collect knowledge and perception of farmers, NGOs, agro-industries, administrations, donors and researchers on barriers and coping strategies for 4 per 1,000 innovations. Results in both countries reveal the predominance of social and economic barriers such as lack of knowledge or training, increased difficulties of fieldwork, workload, risk handling, funding and social pressure. Biophysical constraints such as limited potential of soil organic matter storage or rainfall scarcity and variability appear more important in Senegal. Identified actions to foster the sequestration of soil carbon call for an improved policy context leading to innovations in land planning, stakeholder communication, demonstration facilities, capacity building or financial support. Fewer constraints and coping strategies mention technical issues, showing that fostering agricultural soil carbon sequestration is more a question of enabling environment than technical innovations or farmers' willingness for change. We conclude that actions to support the 4 per 1,000 Initiative need to include a variety of stakeholders such as extension services, private sector, civil society, local institutions, policy makers, consumers, and not only farmers
Insights into the ancestral flowers of Ranunculales
No full textInternational audienceThe question of the origin of petals has long been debated in the botanical literature. Ranunculales are characterized by a spectacular floral diversity, particularly at the perianth level. Recent progress in understanding the genetic bases of floral organ identity suggests a single origin for petals in Ranunculaceae contrasting with the traditional morphological hypothesis of repeated evolution. However, perianth evolution at order level remains incompletely understood. Recent advances in the elucidation of phylogenetic relationships within the order now provide a new opportunity to study character evolution with model-based methods. We used ancestral state reconstruction methods that take into account various sources of uncertainty to reconstruct the evolution of floral traits at the scale of Ranunculales using a consensus phylogenetic framework of 144 terminal species representing all families within the order. Ranunculales likely had ancestrally three trimerous whorls of perianth organs differentiated into two categories of petaloid organs differing in their shape. Each whorl was further lost or duplicated. Moreover, our results support the hypothesis of a single origin of highly specialised (elaborate) nectariferous petals within Ranunculaceae
Unsupervised Change Detection Analysis in Satellite Image Time Series using Deep Learning Combined with Graph-Based Approaches
No full textInternational audienceNowadays, huge volume of satellite images, via the different Earth Observation missions, are constantly acquired and they constitute a valuable source of information for the analysis of spatio-temporal phenomena. However, it can be challenging to obtain reference data associated to such images to deal with land use or land cover changes as often the nature of the phenomena under study is not known a priori. With the aim to deal with satellite image analysis, considering a real-world scenario where reference data cannot be available, in this paper, we present a novel end-to-end unsupervised approach for change detection and clustering for satellite image time series (SITS). In the proposed framework, we firstly create bi-temporal change masks for every couple of consecutive images using neural network autoencoders. Then, we associate the extracted changes to different spatial objects. The objects sharing the same geographical location are combined in spatio-temporal evolution graphs that are finally clustered accordingly to the type of change process with gated recurrent unit (GRU) autoencoder-based model. The proposed approach was assessed on two real-world SITS data supplying promising results
Outil Cadastre_NH3 : Évaluer les pratiques réduisant les émissions d’ammoniac au champ
No full textNational audienceL'outil Cadastre_NH3 réalise des cadastres dynamiques des émissions d’ammoniac liées à la fertilisation azotée aux échelles régionale et nationale. Ces informations fines sont indispensables pour améliorer les outils opérationnels de prédiction de la qualité de l’air en France, comme pour évaluer l’influence des différentes pratiques de fertilisation sur ces émissions
Weeds enhance multifunctionality in Arable Lands in South-West of France
No full textInternational audienceThe current challenge in agriculture is to move from intensively managed to multifunctional agricultural landscapes that can simultaneously provide multiple ecological functions (multifunctionality), thus ensuring the delivery of ecosystem services important for human well-being. There is evidence that biodiversity is the main driver of multiple ecosystem functions. However, how biodiversity, and which components of biodiversity are the sources of multifunctionality, remain elusive. In the present study, we explore the role of weed richness and weed abundance as possible sources of ecosystem multifunctionality of an intensive agricultural landscape. Weeds are a key component of the arable field ecosystem trophic network by supporting various ecological functions while being a possible threat for production. We combine empirical data on ten ecosystem functions related to pollination, pest control and soil fertility, and measured across 184 fields cultivated with winter cereal, oilseed rape or hays in the Long Term Socio-Ecological Research site Zone Atelier Plaine & Val de Sèvre. We found that weed diversity was a strong contributor to multifunctionality in all crop types, especially when using the threshold-based approach. The effects of weed diversity were less pronounced for individual ecological functions except for weed seed predation and urease activity. As weeds may have dual effects on yields, we also explored the relationship between ecosystem multifunctionality and yield considering weed abundance. We however found a neutral relationship between yield and ecosystem multifunctionality. These results suggest that field management that maintains high levels of weed diversity can enhance multifunctionality and most ecological functions. Understanding how to maintain weed diversity in agricultural landscapes can therefore help to design sustainable management favoring the delivery of multiple services while maintaining food production. The next challenge will therefore be to assess the relative contribution of management practices, landscape features and weed diversity on ecosystem multifunctionality and yield
Impacts au niveau de l'exploitation agricole de la libéralisation du commerce et de l'élimination de la PAC à travers l'UE: une évaluation utilisant le modèle IFM-CAP
No full textInternational audienceThis paper assesses the farm-level impacts of trade liberalisation and CAP removal across EU using IFM-CAP (Individual Farm Model for CAP Analysis). IFM-CAP is a static positive programming model developed to capture the full heterogeneity of EU farms in terms of feedback to policy representation and impacts. Simulation results show that a small set of farm-types experience an increase in income due to the improvement in prices and yields (e.g. farms spe-cialised in granivores, milk and horticulture), while farms that are most CAP subsidy dependent (e.g. specialist cattle, specialist COP and small farms) lose income by more than 12% at aggregate EU level. As much as 77% of all farms lose income if CAP is removed , while the proportion of most income vulnerable farms almost doubles.Cet article évalue les impacts au niveau de l'exploitation agricole de la libéralisation du commerce et de la suppression de la PAC à travers l'UE en utilisant IFM-CAP (modèle de ferme individuel pour l'analyse de la PAC). IFM-CAP est un modèle de programmation positive statique développé pour prendre en compte la pleine hétérogénéité des exploitations agricoles de l'UE en termes de représentation et d'impact des politiques. Les résultats de la simulation montrent qu'un petit ensemble d'exploitation agricole type enregistre une augmentation de revenu en raison de l'amélioration des prix et des rendements (par exemple, les exploitations spécialisées dans les granivores, le lait et l'horticulture), tandis que les exploitations qui dépendent le plus de la PAC (par exemple celles spécialisées en bovins et en COP et les petites exploitations) perdent plus de 12% des revenus au niveau agrégé de l'UE. Jusqu'à 77% de toutes les exploitations agricoles perdent des revenus si la PAC est supprimée, tandis que la proportion des exploitations agricoles les plus vulnérables double
Conceptual basis, formalisations and parameterization of the STICS crop model, second edition
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Inhibition of jasmonate-mediated plant defences by the fungal metabolite higginsianin B
No full textInternational audienceInfection of Arabidopsis thaliana by the ascomycete fungus Colletotrichum higginsianum is characterized by an early symptomless biotrophic phase followed by a destructive necrotrophic phase. The fungal genome contains 77 secondary metabolism-related biosynthetic gene clusters, whose expression during the infection process is tightly regulated. Deleting CclA, a chromatin regulator involved in the repression of some biosynthetic gene clusters through H3K4 trimethylation, allowed overproduction of three families of terpenoids and isolation of 12 different molecules. These natural products were tested in combination with methyl jasmonate, an elicitor of jasmonate responses, for their capacity to alter defence gene induction in Arabidopsis. Higginsianin B inhibited methyl jasmonate-triggered expression of the defence reporter VSP1p:GUS, suggesting it may block bioactive jasmonoyl isoleucine (JA-Ile) synthesis or signalling in planta. Using the JA-Ile sensor Jas9-VENUS, we found that higginsianin B, but not three other structurally related molecules, suppressed JA-Ile signalling by preventing the degradation of JAZ proteins, the repressors of jasmonate responses. Higginsianin B likely blocks the 26S proteasome-dependent degradation of JAZ proteins because it inhibited chymotrypsin-and caspase-like protease activities. The inhibition of target degradation by higginsianin B also extended to auxin signalling, as higginsianin B treatment reduced auxin-dependent expression of DR5p:GUS. Overall, our data indicate that specific fungal secondary metabolites can act similarly to protein effectors to subvert plant immune and developmental responses
Surprising low diversity of the plant pathogen Phytophthora in Amazonian forests
No full textInternational audienceThe genus Phytophthora represents a group of plant pathogens with broad global distribution. The majority of them causes collar and root-rot of diverse plant species. Little is known about Phytophthora communities in forest ecosystems, especially in Neotropical forests where natural enemies could maintain the huge plant diversity via negative density dependence. We characterized the diversity of soil-borne Phytophthora communities in the North French Guiana rainforest and investigated how they are structured by host identity and environmental factors. In this little-explored habitat, 250 soil cores were sampled from ten plots hosting ten different plant families across three forest environments (Terra Firme, Seasonally Flooded and White Sand). Phytophthora diversity was studied using baiting approach and metabarcoding (High Throughput Sequencing) on environmental DNA extracted from both soil samples and baiting-leaves. These three approaches revealed very similar communities, characterized by an unexpected low diversity of Phytophthora species, with the dominance of two cryptic species close to Phytophthora heveae. As expected, Phytophthora community composition of French Guiana rainforest was significantly impacted by the host plant family and environment. However, these plant pathogen communities are very small and are dominated by generalist species, questioning their potential roles as drivers of plant diversity in these Amazonian forests