Architectural analysis provides a powerful analytical framework for understanding the ontogenetic trajectories of tree species and their adaptive responses to environmental constraints. Despite their ecological, economic, and cultural importance in West African agroforestry systems, the architectural development of Khaya senegalensis (Desr.) A. Juss. (Meliaceae) and Pterocarpus erinaceus Poir. (Fabaceae), two overexploited taxa classified as Vulnerable on the IUCN Red List, had never been formally described. This study presents the first complete characterization of their architectural development, from the seedling stage to senescence, based on architectural and retrospective analyses conducted on 360 individuals per species across seven localities along a south-north bioclimatic gradient in Côte d'Ivoire, covering contrasting vegetation zones ranging from dense humid forest to dry Sudanian savanna. Both species display well-defined ontogenetic trajectories comprising four phases: juvenile establishment, architectural construction, reproductive transition, and crown restructuring associated with ageing. Distinct architectural models were identified: K. senegalensis conforms to Rauh's model, characterized by a monopodial orthotropic trunk with indefinite growth and rhythmic acrotonic branching; P. erinaceus follows Troll's model, in which the orthotropic trunk progressively gives rise to a sympodial plagiotropic system with mixed terminal and lateral flowering. Architectural units, defined as the minimal structural organization enabling a species to reach reproductive maturity, were established at the adult stage: that of K. senegalensis comprises four axis categories and five branching orders, while that of P. erinaceus comprises three axis categories and up to six branching orders in old trees. Significant variation in growth-unit morphology among habitats and localities ( P<0.05 ) revealed the architectural plasticity of both species in response to ecological gradients. The calculated Favourable Development indices ( FDi ) identified Bouaké and Katiola as optimal zones for K. senegalensis , and Bouaké and Toumodi for P. erinaceus , providing objective spatial criteria for reforestation planning. These findings demonstrate that architectural traits are robust indicators of development, adaptive strategies, and crown functioning. By linking structural organization to productivity, resilience, and regeneration potential, this study provides a scientific basis for integrating architectural analysis into reforestation programmes, sustainable forest management, and the design of agroforestry systems for threatened African tree species facing growing climatic and anthropogenic pressures. Complementary regression analyses further showed that phytomer number, rather than internode elongation, primarily governs growth-unit length in both species, and that growth unit diameter scales positively with growth unit length; a multivariate analysis of variance (MANOVA) confirmed that ontogenetic stage and locality, but not habitat alone, robustly structure growth-unit morphology.

The red blood cell (RBC) membrane is composed of a lipid bilayer and a cytoskeleton interconnected by protein junction complexes, allowing for potential sliding between the lipid bilayer and the cytoskeleton. Despite this biological reality, it is most often modelled as a single-layer model, a hyperelastic capsule or a fluid vesicle. Another approach involves incorporating the membrane's composite structure using double layers, where one layer represents the lipid bilayer and the other represents the cytoskeleton. In this paper, we computationally assess the various modelling strategies by analysing RBC behaviour in extensional flow and four distinct regimes that simulate RBC dynamics in shear flow. The proposed double-layer strategies, such as the vesicle-capsule and capsule-capsule models, account for the fluidity and surface incompressibility of the lipid bilayer in different ways. Our findings demonstrate that introducing sliding between the layers offers the cytoskeleton a considerable degree of freedom to alleviate its elastic stresses, resulting in a significant increase in RBC elongation. Surprisingly, our study reveals that the membrane modelling strategy for RBCs holds greater importance than the choice of the cytoskeleton's reference shape. These results highlight the inadequacy of considering mechanical properties alone and emphasise the need for careful integration of these properties. Furthermore, our findings fortuitously uncover a novel indicator for determining the appropriate stress-free shape of the cytoskeleton.

The architectural plasticity forms observed in trees is a result of meristem functioning, which generates new organs and branches, and adjusts growth processes in response to heterogeneous climatic adaptations that affect biomass allocation. Analyzing this plasticity should enable the selection of adapted individuals for optimizing successful cropping systems. Mahogany tree (Khaya senegalensis) is a rhythmically growing indigenous agroforestry tree that is heavily exploited for its multiple uses. Understanding its growth characteristics, as well as the complexity of its structure (randomness, rhythmicity, etc. of Mahogany tree), could facilitate its conservation and sustainable management. This study aims to model the architecture and physiology of young mahogany trees based on field data using an organ-level structural-functional model called 'GreenLab', which is founded on source-sink relationships. Ninety trees aged 6, 12, and 24 months were measured in the field. Development was calculated using a dual-scale automaton based on the Monte Carlo process, while biomass production and its distribution to different plant organs (source and sink) were calibrated using Pressler's law using Markov chains. Meristematic activity laws, combined with organ sinks (D: Demand), photosynthesis (Q: Supply), and organic series (Q/D: Trophic pressure), were employed to simulate individual architecture. The results demonstrate that the model realistically and flexibly describes topological development and replicates biomass production and allocation processes for rhythmically growing trees. This model will enable the identification of mahogany ideotypes suited for enhancing agroforestry cropping systems based on this species and several other threatened species. These findings introduce and thus lay the groundwork for a computational plant model tailored to the needs of agroforestry from a novel perspective, offering new avenues for agronomic and forestry applications in West Africa and Cote d'Ivoire.

Drops in extensional flow undergo a deformation, which is primarily fixed by a balance between their surface tension and the viscous stress. This deformation, predicted and measured by Taylor on millimetric drops, is expected to be affected by the presence of surfactants but has never been measured systematically. We provide a controlled experiment allowing us to measure this deformation as a function of the drop size and of the shear stress for different surfactants at varying concentrations. Our observation is that the deformation predicted by Taylor is recovered at zero and high surfactant concentration, whereas it is smaller at concentrations close to the critical micellar concentration. This is in contradiction to the existing analytical models. We develop a new analytical model, taking into account the surfactant dynamics. The model predicts a transition between a deformation similar to that of a pure liquid and a smaller one. We show that the transition is driven by a parameter KL, which compares adsorption and desorption dynamics. Finally, the concentration C*, at which we observe this transition in the extensional flow is in good agreement with the one predicted by independent measurements of KL.

Coupling plant growth model with pests and diseases (P&D) models, with consideration for the long-term feedback that occurs after the interaction, is still a challenging task nowadays. While a number of studies have examined various methodologies, none of them provides a generic frame able to host existing models and their codes without updating deeply their architecture. We developed MIMIC (Mediation Interface for Model Inner Coupling), an open-access framework/tool for this objective. MIMIC allows to couple plant growth and P&D models in a variety of ways. Users can experiment with various interaction configurations, ranging from a weak coupling that is mediated by the direct exchange of inputs and outputs between models to an advanced coupling that utilizes a third-party tool if the models’ data or operating cycles do not align. The users decide how the interactions operate, and the platform offers powerful tools to design key features of the interactions, mobilizing metaprogramming techniques. The proposed framework is demonstrated, implementing coffee berry borers’ attacks on Coffea arabica fruits. Observations conducted in a field in Sumatra (Indonesia) assess the coupled interaction model. Finally, we highlight the user-centric implementation characteristics of MIMIC, as a practical and convenient tool that requires minimal coding knowledge to use.

The controlled rupture of a core-shell capsule and the timely release of encapsulated materials are essential steps of the efficient design of such carriers. The mechanical and physico-chemical properties of their shells (or membranes) mainly govern the evolution of such systems under stress and notably the link between the dynamics of rupture and the mechanical properties. This issue is addressed considering weakly cohesive shells made by the interfacial complexation of Chitosan and PFacid in a planar extensional flow. Three regimes are observed, thanks to the two observational planes. Whatever the time of reaction in membrane assembly, there is no rupture in deformation as long as the hydrodynamic stress is below a critical value. At low times of complexation (weak shear elastic modulus), the rupture is reminiscent of the breakup of droplets: a dumbell or a waist. Fluorescent labelling of the membrane shows that this process is governed by continuous thinning of the membrane up to the destabilization. It is likely that the membrane shows a transition from a solid to liquid state. At longer times of complexation, the rupture has a feature of solid-like breakup (breakage) with a discontinuity of the membrane. The maximal internal constraint determined numerically marks the initial location of breakup as shown. The pattern becomes more complex as the elongation rate increases with several points of rupture. A phase diagram in the space parameters of the shear elastic modulus and the hydrodynamic stress is established.

Agroforestry systems are complex due to the diverse interactions between their elements, and they develop over several decades. Existing numerical models focus either on the structure or on the functions of agroforestry systems. However, both of these aspects are necessary, as function influences structure and vice versa. Here, we present a representation of agroforestry systems based on combinatorial maps (which are a type of multidimensional graphs), that allows conceptualizing the structure–function relationship at the agroecosystem scale. We show that such a model can represent the structure of agroforestry systems at multiple scales and its evolution through time. We propose an implementation of this framework, coded in Python, which is available on GitHub. In the future, this framework could be coupled with knowledge based or with biophysical simulation models to predict the production of ecosystem services. The code can also be integrated into visualization tools. Combinatorial maps seem promising to provide a unifying and generic description of agroforestry systems, including their structure, functions, and dynamics, with the possibility to translate to and from other representations.

A finite element model has been developed for the computation of melting/ solidifying process under the combined action of buoyancy and surface tension forces. Validated on the square cavity benchmark of Gobin and Le Quéré (Bertrand et al. [3] , Gobin and Le Quéré [17]), the numerical model is used to extend this previous analysis to the free surface case where surface tension can drive the flow (capillary flow). A comparison of the results obtained for three types of boundary conditions applied at the top of the melting pool is performed. It shows that in the studied case of tin where the thermal Bond number is moderated (Bo = 200), the flow is still mainly dominated by buoyancy effect as long as the melted pool is deep enough like in the square cavity case of the above mentioned benchmark.

We report on a systematic numerical exploration of the vesicle dynamics in a channel, which is a model of red blood cells in microcirculation. We find a spontaneous transition, called swirling, from straight motion with axisymmetric shape to a motion along a helix with a stationary deformed shape that rolls on itself and spins around the flow direction. We also report on a planar oscillatory motion of the mass center, called three-dimensional snaking, for which the shape deforms periodically. Both emerge from supercritical pitch-fork bifurcation with the same threshold. The universality of these oscillatory dynamics emerges from Hopf bifurcations with two order parameters. These two oscillatory dy-namics are put in the context of vesicle shape and dynamics in the parameter space of reduced volume v, capillary number, and confinement. Phase diagrams are established for v = 0.95, v = 0.9, and v = 0.85 showing that oscillatory dynamics appears if the vesicle is sufficiently deflated. Stationary shapes (parachute/bullet/peanut, croissant, and slipper) are fixed points, while swirling and snaking are characterized by two limit cycles.

Seed size is a critical factor that can impact the regeneration process of plant populations. The objective of this study is to identify optimal seeds for the cultivation of two overexploited native forest species in Côte d’Ivoire, namely Khaya senegalensis (Desr.) A.Juss., 1830 and Parkia biglobosa (Jacq.) R.BR. ex G. Don, 1830. A total of 1080 seeds per species were evaluated for germination and seedling vigour in two distinct environments (dry and humid) in Côte d’Ivoire. The results demonstrated that, for Khaya senegalensis, larger seeds exhibited higher germination rates, whereas for Parkia biglobosa, smaller and medium-sized seeds showed better germination performance. However, regardless of species and study site, larger seeds consistently produced more vigorous seedlings. In this case, pretreatment tests on large seeds of Parkia biglobosa can potentially enhance their germination performance. Large seeds, ranging from 0.25–0.37 g in Khaya senegalensis and 0.2–0.32 g in Parkia biglobosa, appear to be the most suitable and best candidates for high-quality, high-performance seeds to optimise the cultivation of these species in Côte d’Ivoire. Distributing such seeds to farmers can contribute to the success of reforestation and agroforestry programs involving these target species in Côte d’Ivoire. These findings contribute to the sustainable management of the target species and can serve as a basis for restructuring forest regeneration policies in Côte d’Ivoire.

Seed size is a key factor that can affect the regeneration process of plant populations. This study aims to identify efficient seeds that can optimise the cultivation of two overexploited native forest species in Côte d'Ivoire, namely Khaya senegalensis and Parkia bliglobosa . Sets of 1080 seeds per species were tested for their germination and seedling vigour in two distinct environments (dry and humid) in Côte d'Ivoire. The results showed that, for optimized germination, large seeds were preferable for Khaya senegalensis while for Parkia biglobosa , on the contrary, small and medium seeds were preferable. However, the most vigorous seedlings were generated by germinating large seeds regardless of species and study site. In this case, pre-treatment tests on large seeds in Parkia biglobosa are possible to improve their germination performance. Large seeds appear to be the best candidates for high quality, high performance seeds that can optimise the cultivation of Khaya senegalensis (0.25-0.37g) and Parkia biglobosa (0.25-0.37g) in Côte d'Ivoire. They can be provided to farmers to assist in the success of replanting programmes (reforestation and agroforestry) using the target species in Côte d'Ivoire. These results can contribute to the sustainable management of the target species and serve as a basis for restructuring forest regeneration policy in Côte d'Ivoire.

Parkia biglobosa is a much-loved and over-exploited African savannah species for its socio-economic importance. Knowing and taking into account its architectural unit, which is the basis for diagnosing phenology, productivity and tree health, could provide a new perspective on its sustainable management. The aim of this study is to establish the architectural development in Parkia biglobosa by retrospective analysis. To achieve this objective, 390 individuals of all sizes ranging from seedlings to senescent trees were observed and analysed under various soil and climatic conditions in Côte d’Ivoire. The results showed that Parkia biglobosa is a light plant but shading tolerant. It is a mixed vegetative axis plant, the stem phytomere, the module or growth unit, the axis, the architectural unit and the reiterated complex. Retrospective analysis of the modules showed that the dimensions of the growth units are indicators of morphological variation and species adaptation to a changing climate (P < 0.05). However, the equations generated by the morphological and habitat dimension linkage models are not significant (R 2 and r < 0.7) to be used as a guide for field data collection. This study represents an initiation into the architectural study of this species and the information provided will serve as a basis for further research into the architecture in relation to the sustainable use of this species.

This review retraces the history of the GreenLab functional structural plant model and its current status, highlighting three aspects: (i) What are the main features of the GreenLab model? (ii) How can the model be a guide for defining relevant measurement strategies and experimental protocols? and (iii) What kind of applications can such a model address? This question is answered using case studies as illustrations and through the discussion. Results obtained over two decades show the GreenLab model to be an efficient synthesis between the structural models and the crop models, allowing for passage from plant individual level to crop scale.