HAL Portal Univ-Côtedazur
Not a member yet
95391 research outputs found
Sort by
Identifying Retailscape Transformations: A Methodological Framework for Spatiotemporal Analysis in Urban Environment
No full textInternational audienc
High alpine preglacial caves modified by glacial processes and late condensationcorrosion in the Scerscen Valley (Valmalenco, Western Alps, Italy)
No full textInternational audienceThe Scerscen Valley (western Italian Alps) is home to caves at an altitude of around 2600 m, opening close to the Speleogenesis edge of a glacier. The aim of the research as part of a multi-disciplinary project was to reconstruct the evolution Alpine Cosmogenic GeomorphologyHydrogeologyglaciersburial dating of cosmonucleide some the of caves the related most burial recent to dating, the processes, geological recorded such and morphology paleoenvironmental as condensation-corrosion and micrometeorology, evolution and of sediment the carried area deposition. and out mineralogical to evaluate We the performed identifirole of cation by XRD, and hydrogeology using dye tracing and physical and chemical analyses. The cosmonucleide dating of quartz pebbles showed that the Veronica Cave is the oldest, with deposits dated at 1.3 ± 0.4 Ma, and possibly even older. It certainly formed at a much lower altitude (approx. 1300 m a.s.l. or lower) during the Alpine uplift. The Morgana and Marsooi caves, given the smaller volume of their phreatic conduits (1/3 of Veronica), are possibly more recent, formed during interglacials and evolved close to a glacial body. The caves initiated in dolomitic marble under the influence of sulfuric acid speleogenesis (SAS) due to pyrite oxidation. The conduits were then enlarged dramatically under phreatic conditions. The caves have evolved since their preglacial formation, with phases of filling by fluvio-glacial sediments and unclogging. Water tracing and physico-chemical analysis attest to a well-karstified aquifer, with rapid water circulation (>20 m/h) and low temperatures (~2 °C), draining towards the main spring, "La Prediletta", located at the foot of the dolomitic marbles. Microclimatic records (cave temperature and humidity) show seasonal cycles of condensation and evaporation, influenced by air exchanges with the outside atmosphere. These processes contributed to the formation of secondary minerals by evaporation (gypsum, hydromagnesite…) and, above all, to the significant enlargement of passages by the retreat of walls with characteristic morphologies (facets and grooved walls). The Scerscen caves bear witness to a long geological and climatic history, from their formation before the Mid-Pleistocene ice ages to their present-day evolution. They offer valuable insights into karst processes in the high mountains, and interactions between glaciers and aquifers
Chapter 11 - Organ communication in insects during growth and development
No full textInternational audienceThis chapter aims at summarizing examples of organ communication and formulating possible underlying principles about the cellular and molecular pathways in insect development and growth. Some of these examples of organ communication are explicitly verbalized as a problem of organ communication in the literature, while others are not, and therefore their inclusion here relies on my interpretation. Generally, we distinguish between the embryo that develops and differentiates in a closed system within the egg case and the stages outside the embryo and before metamorphosis that constantly receive information especially nutrients from an open system, the environment
Toughness Properties of Arbitrarily Partitionable Graphs
No full textInternational audienceDrawing inspiration from a well-known conjecture of Chv\'atal on a toughness threshold guaranteeing graph Hamiltonicity, we investigate toughness properties of so-called arbitrarily partitionable (AP) graphs, which are those graphs that can be partitioned into arbitrarily many connected graphs with arbitrary orders, and can be perceived as a weakening of Hamiltonian and traceable graphs. In particular, we provide constructions of non-AP graphs with toughness about , \textit{i.e.}, in which, when removing the vertices of any cut-set , the number of resulting connected components is at most about . We also consider side related questions on graphs that can be partitioned arbitrarily into only a few connected graphs (with arbitrary orders). Among other things, we prove that not all -tough graphs can always be partitioned into four connected graphs this way. As going along, we also raise several other questions and problems of interest on the topic
Conception et implémentation d'une ontologie des facteurs psychosociaux liés aux attitudes et comportements alimentaires dysfonctionnels chez les sportifs
No full textNational audienceDysfunctional eating attitudes and behaviors (DEAB), represent complex phenomena linked to multiple psychosocial factors in the context of sport. Current research in this field shows high complexity and inconsistencies concerning the theoretical concepts used, the measurement tools employed, and the relationships between these concepts. In this context, we developed an ontology of factors related to DEAB in sport, aiming for a better understanding of the complexity of the relationships between these factors. This paper presents this ontology and the knowledge graph built from a scientific literature review.Les attitudes et comportements alimentaires dysfonctionnels (ACAD) représentent des phénomènes complexes liés à de multiples facteurs psychosociaux dans le contexte sportif. Les recherches actuelles dans ce domaine présentent une forte complexité et des inconsistances concernant les concepts théoriques mobilisés, les outils de mesure utilisés et les relations entre ces concepts. Dans ce contexte, nous avons développé une ontologie des facteurs psychosociaux liés aux ACAD en sport permettant une meilleure compréhension de la complexité des relations entre ces facteurs. Cet article présente l'ontologie développée et le graphe de connaissances construit à partir d'une revue de la littérature scientifique
Impact of wheat-legume mix intercrops on wheat epidemics by modelling
No full textInternational audienceHighlights: • Simulated intercropping decrease disease intensity and improve protectiveness while canopy indicators predict such effects. • Pea intercropped with wheat decreased disease intensity compared with faba bean. • Nitrogen fertilization increased disease intensity. • This study stressed the critical lack of experimental data on disease in intercropping.Abstract: Context : Intercropping is a promising strategy for integrated disease management and agroecological transition, although experimental and modelling studies are scarce.Objectives: This study aims to understand and quantify the impact of non-host species choice and nitrogen (N) fertilization on disease epidemics in the context of intercropping.Methods: We collected existing experimental data on LAI based on a literature survey of non-diseased wheat intercropped with different non-host legume species (pea and faba bean) and N fertilization treatments. Based on a foliar epidemic model for intercropping, we simulated epidemics directly on these experimental data of LAI. The model is parameterized for two wheat fungal diseases: Septoria tritici blotch, a rain-borne disease, and wheat leaf rust, an air-borne disease.Results: Our results indicate that intercropping can decrease disease intensity and improve protectiveness for both diseases. Effect depends however on species choice as pea intercropped with wheat leads to lower disease intensity and better intercropping protectiveness compared with faba bean, whereas N fertilization increased disease intensity. We also found that crop indicators describing wheat leaf area index (LAI) can predict disease intensity, whereas indicators describing companion LAI can better predict intercropping protectiveness.Conclusions: Intercropping can significantly reduce fungal epidemics on wheat, and intercropping management practices can be optimized for effective disease management in wheat-legume intercrops. The dilution effect is more related to disease intensity, while the barrier effect is more related to intercropping protectiveness.Implications: These findings pave the way for identifying field indicators to predict epidemics. However, this study also stressed the critical lack of experimental data on disease in intercropping
Le droit comptable et le droit fiscal, facteurs d’(in)effectivité des objectifs climatiques
No full textInternational audienc
The Harmonious Coloring Game
No full textInternational audienceA harmonious k-coloring of a graph G is a 2-distance proper k-coloring of its vertices such that each edge is uniquely identified by the colors of its endpoints. Here, we introduce its game version: the harmonious coloring game. In this two-player game, Alice and Bob alternately select an uncolored vertex and assigns to it a color in {1,...,k} with the constraint that, at every turn, the set of colored vertices induces a valid partial harmonious coloring. Alice wins if all vertices are colored; otherwise, Bob wins. The harmonious game chromatic number is the minimum integer k such that Alice has a winning strategy with colors. In this paper, we prove the PSPACE-hardness of three variants of this game. As a by-product, we prove that a variant introduced by Chen et al. in 1997 of the classical graph coloring game is PSPACE-hard even in graphs with diameter two. We also obtain lower and upper bounds for in graph classes, such as paths, cycles, grids and forests of stars
DIVA: An Ontology-based Approach to Model User Activity within Visualization Systems
No full textInternational audienceThe study of user activity supports evaluation of visualization systems, recommendation of suitable views or tasks, guidance of interaction, and validation of analytical results. It enables researchers to understand how these visualization systems are used and to gain insight into users' reasoning processes during data exploration. However, there is a lack of structured frameworks for systematically collecting and reasoning over such data. In this paper, we build upon Semantic Web standards to model and represent user activity as knowledge graphs. We introduce an OWL ontology specifically designed for this purpose and demonstrate its application by transforming system log data-collected during user studies with a multiview visualization tool for urban mobility data exploration-into an RDF knowledge graph. Finally, we illustrate the utility and expressiveness of our model by enabling intuitive exploration and interpretation of user activity through the implementation of competency questions as SPARQL queries and the visualization of these queries' results on the RDF graph representing user activity
Can we detect soil salinity in ancient arid agricultural soils? A geoarchaeological, physico-chemical and micromorphological investigation (Oasis of Masafi, UAE)
No full textInternational audienceOases are key agricultural landscapes in semi-arid to hyper-arid regions. They are currently threatened by socio-economic shifts, decreasing water-soil resources and rising salinity issues. In the UAE, the Masafi oasis has been farmed for millennia, prompting questions about how ancient societies managed salinity. To assess current salinity, we collected surface water samples and salt efflorescences in the oasis. To analyse how agricultural and hydraulic practices influence salt accumulation and leaching processes, we studied a Reference Pit in a plot in which we collected soil samples and a continuous core for a 3-month laboratory experiment of reconstructed irrigation practices. Sedimentological, physico-chemical and micromorphological analyses were performed before and after irrigation. Results were confronted with similar analyses processed in an Archaeological Pit in which ancient cultivated soils were identified. Findings show that Masafi soils currently face salinity-sodicity problems. Salt accumulation was also found in ancient soils. These traces may have been preserved thanks to the burial of these soils under thick non-cultivated sediments and gully deposits, along with reduced irrigation and increased evaporation. Changes in salt composition over time suggest shifts in water quality, highlighting the role of both natural and human-driven processes in the long-term evolution of oasis agriculture