Processes analogous to ecological interactions and dispersal shape the dynamics of economic activities

The processes of ecological interactions, dispersal and mutations shape the dynamics of biological communities, and analogous eco-evolutionary processes acting upon economic entities have been proposed to explain economic change. This hypothesis is compelling because it explains economic change through endogenous mechanisms, but it has not been quantitatively tested at the global economy level. Here, we use an inverse modelling technique and 59 years of economic data covering 77 countries to test whether the collective dynamics of national economic activities can be characterised by eco-evolutionary processes. We estimate the statistical support of dynamic community models in which the dynamics of economic activities are coupled with positive and negative interactions between the activities, the spatial dispersal of the activities, and their transformations into other economic activities. We find strong support for the models capturing positive interactions between economic activities and spatial dispersal of the activities across countries. These results suggest that processes akin to those occurring in ecosystems play a significant role in the dynamics of economic systems. The strength-of-evidence obtained for each model varies across countries and may be caused by differences in the distance between countries, specific institutional contexts, and historical contingencies. Overall, our study provides a new quantitative, biologically inspired framework to study the forces shaping economic change.Comment: 23 page

Central Collisions of Au on Au at 150, 250 and 400 A MeV

Collisions of Au on Au at incident energies of 150, 250 and 400 A MeV were studied with the FOPI-facility at GSI Darmstadt. Nuclear charge (Z < 16) and velocity of the products were detected with full azimuthal acceptance at laboratory angles of 1-30 degrees. Isotope separated light charged particles were measured with movable multiple telescopes in an angular range of 6-90 degrees. Central collisions representing about 1 % of the reaction cross section were selected by requiring high total transverse energy, but vanishing sideflow. The velocity space distributions and yields of the emitted fragments are reported. The data are analysed in terms of a thermal model including radial flow. A comparison with predictions of the Quantum Molecular Model is presented.Comment: LateX text 62 pages, plus six Postscript files with a total of 34 figures, accepted by Nucl.Phys.

Entropy production in the Au + Au reaction between 150 and 800 A MeV

The entropy per nucleon (S/A) has been extracted for the Au [(150—800)A MeV] + Au reaction by using the phase I setup of the 4 pi facility at GSI, Darmstadt. The entropy has been obtained from the comparison of various observables characterizing the dM/dZ fragment multiplicity distributions, extending up to Z~15, with those calculated with the quantum statistical model. It is the first time that S/A values are determined by considering the full ensemble of charged products detected in the reaction. Consistent values of S/A are found from different methods. These entropy values are shown to be fairly independent of the volume of the ``participant'' region considered. They are somewhat lower than those extracted in earlier works but are in good agreement with hydrodynamic calculations and suggest a low viscosity for the hot and dense nuclear matter

Forward and inverse modelling of eco-evolutionary dynamics: in ecological and economic systems

Ecological and economic systems are complex adaptive systems, composed of multiple entities structured at different organizational levels – from genes to ecological communities and from individual behavioral rules to national economies –, that interact between themselves and their environment, and experience evolutionary processes. The processes operating at the different organizational scales affect each other, generating complex couplings across scales. Yet, despite this astonishing organizational complexity, ecological and economic systems both display invariant patterns. A fundamental challenge in the study of ecological and economic systems is to identify the general organizational principles from which these patterns originate. Recently, studies have shown that evolutionary processes can occur on similar time scales as ecological processes, generating eco-evolutionary feedbacks which may play an important role on the dynamics of ecological systems. In parallel, studies on economic systems suggest that economic change is determined by analogous eco-evolutionary processes. Yet, our understanding of eco-evolutionary processes and feedback mechanisms in empirical systems is limited, because of the oversimplicity of current eco-evolutionary models and a lack of confrontation with empirical data. By developing novel modelling approaches to improve the modelling of empirical systems, this thesis advances our general understanding of the eco-evolutionary processes and feedbacks shaping the dynamics of ecological and economic systems. Specifically, Chapter 2 presents and analyses an eco-evolutionary model on spatial graphs to understand how eco-evolutionary processes, together with complex habitat structures, influence the phenotypic distribution of biological populations. Chapter 3 presents an inverse modelling framework to estimate the most likely parameter values of dynamical models from empirical data, granting the opportunity to discriminate between competing eco-evolutionary hypotheses. Chapter 4 tests whether processes operating on economic activities, consisting of positive and negative interactions between them, their spatial dispersal and their transformations, can explain their dynamics at the country level. To reach this goal, the inverse modelling framework, together with data covering 59 years of economic time series over 74 countries, are used. Finally, Chapter 5 presents two numerical methods to efficiently simulate eco-evolutionary models of biological populations that are structured in high dimensional spatial and phenotypic spaces. This thesis altogether advances our general understanding of the eco-evolutionary processes and feedbacks shaping the dynamics of biological populations and economic activities. A comprehensive mapping of elemental eco-evolutionary feedbacks influencing spatially structured biological populations is established. As regards economic activities, processes involving positive interactions between themselves and spatial dispersal are evidenced to systematically affect their dynamics at the country scale. In parallel to those fundamental results, novel forward and inverse modelling methods are developed, allowing to better capture the dynamics of empirical systems. In the face of the ongoing climate and biodiversity crisis, there is an urgent need to accelerate our general understanding of the mechanisms shaping our world. Bridging biology, mathematical modelling, machine learning and economics, the approaches developed in this thesis can massively help us to reach this goal

Adam Ferguson and commercial Society : a reflection on social order at the dawn of Industrial modernity

Comment l’ordre social est-il possible et qu’est-ce qui lui assure sa légitimité ? Suite aux bouleversements profonds que connaît la société à l’orée de la modernité industrielle, la société commerçante offrirait moult promesses : l’éradication de la pauvreté, de la violence et de la guerre. On lui reproche cependant de développer l’égoïsme de l’agent, de produire des inégalités, de dissoudre le lien social et finalement de mettre en péril l’existence en société. Loin de résoudre un problème de sociabilité, la société commerçante serait, au contraire, confrontée à des difficultés nombreuses. Cette thèse étudie la position d’Adam Ferguson (1723-1816) qui identifie d’emblée le caractère problématique de la société commerçante à partir d’une réflexion sur l’ordre spontané et la motivation morale de l’agent. Grâce à l’examen de la philosophie et de la psychologie morales qu’il développe en dialogue avec ses contemporains – Smith, Rousseau, Hume, Mandeville et Hutcheson, entre autres –, cette étude propose une nouvelle approche de cet auteur qui met en lumière l’originalité et la cohérence de sa pensée et l’inscrit pleinement dans les débats sur l’ordre social appelés par le développement du commerce et de l’industrialisation. Cette thèse offre ainsi un nouvel éclairage sur les discussions concernant la société commerçante au XVIIIe siècle, en mettant au jour certains aspects inexplorés de l’œuvre de l’un de ses principaux interlocuteurs et, ce faisant, permet de mieux cerner ce qu’est la société commerçante et ce qu’elle présuppose.How is social order possible and what ensures its legitimacy? Following the profound changes society experienced at the dawn of industrial modernity, commercial society seemed to offer many promises, such as the eradication of poverty, violence, and war. However, its critics reproach it with developing the egoism of the agent, producing inequalities, dissolving social bonds, and finally for jeopardizing existence in society itself. Far from solving a problem of sociability, commercial society would, on the contrary, be faced with many difficulties. This thesis examines the position of Adam Ferguson (1723 – 1816), who uses his reflection on spontaneous order and the moral motivation of the agent as a basis to immediately identify the problematic nature of commercial society. By looking at the moral philosophy and psychology he developed in dialogue with his contemporaries – Smith, Rousseau, Hume, Mandeville, and Hutcheson, among others – this study offers a new approach to this author that sheds light on the originality and the coherence of his thought and situates him squarely within the debates on social order that came about with the growth of commerce and industrialization. This thesis thus provides a new perspective on discussions concerning commercial society in the 18th century, bringing to light certain unexplored aspects of the work of one of the main individuals engaging with it and, in so doing, allows us to better understand what commercial society is and what it presuppose

La rotation des opioïdes (étude descriptive au sein d'un centre régional de lutte contre le cancer)

LYON1-BU Santé (693882101) / SudocSudocFranceF

Eco-evolutionary model on spatial graphs reveals how habitat structure affects phenotypic differentiation

Differentiation mechanisms are influenced by the properties of the landscape over which individuals interact, disperse and evolve. Here, we investigate how habitat connectivity and habitat heterogeneity affect phenotypic differentiation by formulating a stochastic eco-evolutionary model where individuals are structured over a spatial graph. We combine analytical insights into the eco-evolutionary dynamics with numerical simulations to understand how the graph topology and the spatial distribution of habitat types affect differentiation. We show that not only low connectivity but also heterogeneity in connectivity promotes neutral differentiation, due to increased competition in highly connected vertices. Habitat assortativity, a measure of habitat spatial auto-correlation in graphs, additionally drives differentiation under habitat-dependent selection. While assortative graphs systematically amplify adaptive differentiation, they can foster or depress neutral differentiation depending on the migration regime. By formalising the eco-evolutionary and spatial dynamics of biological populations on graphs, our study establishes fundamental links between landscape features and phenotypic differentiation.ISSN:2399-364