412 research outputs found
Variable time scales, agent-based models, and role-playing games: The PIEPLUE river basin management game
This article presents a specific association of a role-playing game (RPG) and an agent-based model (ABM) aimed at dealing with a large range of time scales. Applications to the field of natural resource management lead one to consider the short time scale of resource use in practice at the same time as the longer ones related to resource dynamics or actors' investments. In their daily practice, stakeholders are translating their long-term strategies, a translation that is contextualized and combined with some cooccurring events. Long-term thinking is required for sustainable use of natural resources, but it should take into account its necessary adaptation on a short time scale. This raises the necessity for tools able to tackle jointly these various time scales. The similarity of architecture between computerized ABMs and RPGs makes them easy to associate in a hybrid tool, targeted at meeting this requirement. The proposition of this article is to allocate the representation of short time scales to computerized ABMs and the long ones to RPGs, while keeping the same static structural conceptual model, shared as a common root by both. This synergy is illustrated with PIEPLUE, an interactive setting tackling water-sharing issues.GESTION DE L'EAU;BASSIN VERSANT;RESSOURCE NATURELLE;MODELE;JEU DE ROLE;SYSTEME MULTIAGENTS;AGENT-BASED MODEL;CASE STUDY OF WATER SHARING;CONCEPTUAL MODEL;HYBRID TOOL;INVESTMENTS;LONG-TERM ISSUES;NATURAL RESOURCE MANAGEMENT;PIEPLUE;PARTICIPATORY MODELING;RESOURCE DYNAMICS;RESOURCE USE;ROLE-PLAYING GAME;STAKEHOLDERS;SUSTAINABLE USE OF NATURAL RESOURCES;TIME-SCALE DIVERSITY;VARIABLE TIME SCALES;WATER MANAGEMENT
Building an Agent-Based Model for exploring how informal rules impact the functioning of newly-established Water User Associations in Central Asia
International audienceIn transition countries informal institutions play a major role and often interfere with new formal institutions leading to large discrepancies between rules on paper and rules in use. We develop an agent-based model to explore the interaction between formal and informal rules and its effect on the performance of the formal institutions, based on the example of water user associations (WUA) in Uzbekistan. The model is based on field experience such as community-based work and role playing games, complemented by available literature. In this paper we present the conceptualization of the model, its empirical foundation and a first baseline scenario. We model a water user association where rules based on formal and informal institutions can be used. The baseline scenario represents the results of a totally formal WUA. In a next step we will introduce informal rules and explore how they can coexist with formal ones. Further work will bring us to question rules' implementation and roles and relationships evolution through selective rules adoption. The model will allow exploring under which conditions the institution WUA can function well and what might be mechanisms for the selection and adoption of rules by individual members
Modelling farm vulnerability to flooding: towards the appraisal of vulnerability mitigation policies
International audienceIn France, two new kinds of flood management policies are promoted: floodplain restoration and vulnerability mitigation. Few experience feedback exist on these policies but they may have strong impacts on farms. Flood management on Rhône River is highly illustrative of these policies and local authorities would like to appraise the efficiency of these policies with an economic tool (Cost-Benefit Analysis) to help decision making. But the current methods of flood damage modelling do not make the appraisal of these policies possible; mainly because they do not take into account the organizational and temporal dimensions of damage formation and propagation at farm scale. After a presentation of the Rhône River context and policies, we review existing methods of flood damage modelling for agriculture and show the interest to focus on the farm scale instead of land plot scale. Based upon the theoretical frameworks for systemic approach, we detail the construction of our conceptual model of farm vulnerability before presenting a case study that shows how the model can be implemented to compute flood damage at farm scale. Finally, the outlooks concerning the use of the model to appraise vulnerability mitigation policies and its application at regional scale are developed
Caractérisation des stratégies de gestion pour la modélisation de la vulnérabilité des exploitations agricoles aux inondations : Lier les dimensions spatiale, organisationnelle et temporelle d'un système complexe
National audienceLes politiques publiques de gestion des inondations s'orientent vers la restauration des champs d'expansion de crue et de réduction de la vulnérabilité, qui auront un impact important sur les exploitations agricoles. L'évaluation des effets de ces politiques sur les exploitations agricoles n'est pas envisageable avec les méthodologies actuelles et le retour d'expérience quasiment inexistant. Il était donc nécessaire de développer un modèle de simulation des dommages directs et induits en prenant en compte la dimension systémique de l'exploitation agricole. Pour cela, nous proposons un modèle conceptuel de la vulnérabilité à l'échelle de l'exploitation agricole et montrons comment il nous a permis de mettre en évidence l'importance des stratégies de gestion post-inondation pour la modélisation des dommages. Nous présentons ensuite les résultats des enquêtes réalisées sur les exploitations arboricoles de la zone aval du Rhône pour la caractérisation de ces stratégies. Enfin, nous montrons comment nous avons intégré dans le modèle de simulation des dommages, les données recueillies par enquêtes. Les premiers résultats de simulation des dommages confirment l'importance de prendre en compte les effets induits de l'inondation sur le système " exploitation agricole ". En perspective, l'utilisation du modèle de simulation des dommages dans le cadre d'une évaluation économique des politiques de réduction de la vulnérabilité des exploitations agricoles sur la zone aval du Rhône est discutée
WAT-A-GAME: sharing water and policies in your own basin
40th Annual Conference, Int. Simulation And Gaming Association, Singapour, SGP, 29-/06/2009 - 03/07/2009International audienceAfter having designed and used various games for learning and supporting water management and governance, many similarities appear. However, the components, topologies, and social and political setting of the basins are different. Therefore we have started designing andvalidating a new generic game platform, WAT-A-GAME, alias AMANZI. This new game aims at facilitating exploration and transformation of water management and water use at the small catchment scale. It gives a simple but enlightening view of the various consequences of individual and collective choices, including regulation policies. After comparing it with some previous games, we discuss its main rationales and features. We show how it can be adapted to very different settings, how players can usefully contribute to designing an instance, and how it can especially address dialogue between multi-level stakeholders. We describe an application in South-Africa, in the Inkomati basin and the preliminary results of this instance
How agency models inspire large scale participatory planning and its evaluation
International audienceWe describe how three models, for sustainable change, human agency in collective resource management, and socio-environmental systems, have been used to design a protocol and the tools for a large scale (1500 participants, 35 villages) multi-level participatory process held in Africa for Integrated Natural Resource Management, through the European Project Afromaison. The process especially combines a common action model to support proposals by stakeholders, an integration matrix to build coherent plans, a role playing game design process, and a method to combine planning and playing to engage into the plans. It has also inspired the design of the attached monitoring and evaluation process. We describe the process in two countries, Ethiopia and Uganda, present the theoretical bases of the evaluation framework using the ENCORE paradigm and the implemented methodology transferred to local evaluators. We introduce some results and propose comments on potential learning back to the modelling community
Modelling farm vulnerability to flooding: towards the appraisal of vulnerability mitigation policies
In France, two new kinds of flood management policies are promoted: floodplain restoration and vulnerability mitigation. Few experience feedback exist on these policies but they may have strong impacts on farms. Flood management on Rhône River is highly illustrative of these policies and local authorities would like to appraise the efficiency of these policies with an economic tool (Cost-Benefit Analysis) to help decision making. But the current methods of flood damage modelling do not make the appraisal of these policies possible; mainly because they do not take into account the organizational and temporal dimensions of damage formation and propagation at farm scale. After a presentation of the Rhône River context and policies, we review existing methods of flood damage modelling for agriculture and show the interest to focus on the farm scale instead of land plot scale. Based upon the theoretical frameworks for systemic approach, we detail the construction of our conceptual model of farm vulnerability before presenting a case study that shows how the model can be implemented to compute flood damage at farm scale. Finally, the outlooks concerning the use of the model to appraise vulnerability mitigation policies and its application at regional scale are developed.Modélisation;Vulnérabilité;Langage UML;Évaluation des risques;Exploitation agricole;Inondation
Investigation on the thermal gelation of Chitosan/\u3b2-Glycerophosphate solutions
This work deals with the effect of temperature on the thermal-gelation process of water solutions containing
chitosan \u3b2-glycerolphosphate disodium salt hydrate. In particular, the attention is focused on the role played by
temperature on the gel final properties, a very important aspect in the frame of drug delivery systems. The study
was performed by combining rheology and low field nuclear magnetic resonance, two approaches that revealed
to be highly synergic as they can detect different aspects of the developing polymeric network. This study
indicates that 30 \ub0C represent a sort of threshold for both the gelation kinetics and the gel final properties.
Indeed, above this temperature, gelation kinetics was rapid and yielded to a strong gel. On the contrary, a slow
kinetics and a final weak gel occurred below 30 \ub0C. Finally, rheology and low field NMR allowed, independently,
evaluating the time evolution of the network mesh size upon gelation
Membrane insertion of anthrax protective antigen and cytoplasmic delivery of lethal factor occur at different stages of the endocytic pathway
The protective antigen (PA) of anthrax toxin binds to a cell surface receptor, undergoes heptamerization, and binds the enzymatic subunits, the lethal factor (LF) and the edema factor (EF). The resulting complex is then endocytosed. Via mechanisms that depend on the vacuolar ATPase and require membrane insertion of PA, LF and EF are ultimately delivered to the cytoplasm where their targets reside. Here, we show that membrane insertion of PA already occurs in early endosomes, possibly only in the multivesicular regions, but that subsequent delivery of LF to the cytoplasm occurs preferentially later in the endocytic pathway and relies on the dynamics of internal vesicles of multivesicular late endosomes
Evidence against a Human Cell-Specific Role for LRP6 in Anthrax Toxin Entry
The role of the cellular protein LRP6 in anthrax toxin entry is controversial. Previous studies showed that LRP6 was important for efficient intoxication of human M2182 prostate carcinoma cells but other studies performed with cells from gene-knockout mice demonstrated no role for either LRP6 or the related LRP5 protein in anthrax toxin entry. One possible explanation for this discrepancy is that LRP6 may be important for anthrax toxin entry into human, but not mouse, cells. To test this idea we have investigated the effect of knocking down LRP6 or LRP5 expression with siRNAs in human HeLa cells. We show here that efficient knockdown of either LRP6, LRP5, or both proteins has no influence on the kinetics of anthrax lethal toxin entry or MEK1 substrate cleavage in these cells. These data argue against a human-specific role for LRP6 in anthrax toxin entry and suggest instead that involvement of this protein may be restricted to certain cell types independently of their species of origin
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