683 research outputs found
What do business models do? Narratives, calculation and market exploration
Building on a case study of an entrepreneurial venture, we investigate the role played by business models in the innovation process. Rather than debating their accuracy and efficiency, we adopt a pragmatic approach to business models -- we examine them as market devices, focusing on their materiality, use and dynamics. Taking into account the variety of its forms, which range from corporate presentations to business plans, we show that the business model is a narrative and calculative device that allows entrepreneurs to explore a market and plays a performative role by contributing to the construction of the techno-economic network of an innovation.WP abstract: Analyzes the uses and functions of business models through original, qualitative case studies focused on research-based spin-offs.Business models; spin-offs; innovation; commercialization; calculation; exploration; R&D; entrepreneurship
Short Run and Long Run Causality in Time Series: Inference
We propose methods for testing hypothesis of non-causality at various horizons, as defined in Dufour and Renault (1998, Econometrica). We study in detail the case of VAR models and we propose linear methods based on running vector autoregressions at different horizons. While the hypotheses considered are nonlinear, the proposed methods only require linear regression techniques as well as standard Gaussian asymptotic distributional theory. Bootstrap procedures are also considered. For the case of integrated processes, we propose extended regression methods that avoid nonstandard asymptotics. The methods are applied to a VAR model of the U.S. economy. Nous proposons des méthodes pour tester des hypothèses de non-causalité à différents horizons, tel que défini dans Dufour et Renault (1998, Econometrica). Nous étudions le cas des modèles VAR en détail et nous proposons des méthodes linéaires basées sur l'estimation d'autorégressions vectorielles à différents horizons. Même si les hypothèses considérées sont non linéaires, les méthodes proposées ne requièrent que des techniques de régression linéaire de même que la théorie distributionnelle asymptotique gaussienne habituelle. Dans le cas des processus intégrés, nous proposons des méthodes de régression étendue qui ne requièrent pas de théorie asymptotique non standard. L'application du bootstrap est aussi considérée. Les méthodes sont appliquées à un modèle VAR de l'économie américaine.time series; Granger causality; indirect causality; multiple horizon causality; autoregression; autoregressive model; vector autoregression; VAR; stationary process; nonstationary process;integrated process; unit root; extended autoregression; bootstrap; Monte Carlo; macroeconomics;money; interest rates; output; inflation, séries chronologiques; causalité; causalité indirecte; causalité à différents horizons; autorégression; modèle autorégressif; autorégression vectorielle; VAR; processus stationnaire; processus non stationnaire; processus intégré; racine unitaire; autorégression étendue; bootstrap; Monte Carlo; macroéconomie; monnaie; taux d'intérêt; production; inflation
What do business models do? Narratives, calculation and market exploration
http://www.csi.ensmp.fr/Items/WorkingPapers/Download/DLWP.php?wp=WP_CSI_012.pdfCSI WORKING PAPERS SERIES 012International audienceBuilding on a case study of an entrepreneurial venture, we investigate the role played by business models in the innovation process. Rather than debating their accuracy and efficiency, we adopt a pragmatic approach to business models -- we examine them as market devices, focusing on their materiality, use and dynamics. Taking into account the variety of its forms, which range from corporate presentations to business plans, we show that the business model is a narrative and calculative device that allows entrepreneurs to explore a market and plays a performative role by contributing to the construction of the techno-economic network of an innovation.WP abstract: Analyzes the uses and functions of business models through original, qualitative case studies focused on research-based spin-offs.Analyse des usages et fonctions des "business models" à partir d'études de cas originaux dans le domaine des entreprises innovantes issues de la recherche
Autophagy plays an important role in protecting Pacific oysters from OsHV-1 and Vibrio aestuarianus infections.
Recent mass mortality outbreaks around the world in Pacific oysters, Crassostrea gigas, have seriously affected the aquaculture economy. Although the causes for these mortality outbreaks appear complex, infectious agents are involved. Two pathogens are associated with mass mortality outbreaks, the virus ostreid herpesvirus 1 (OsHV-1) and the bacterium Vibrio aestuarianus. Here we describe the interactions between these 2 pathogens and autophagy, a conserved intracellular pathway playing a key role in innate immunity. We show for the first time that autophagy pathway is present and functional in Pacific oysters and plays an important role to protect animals from infections. This study contributes to better understand the innate immune system of Pacific oysters.This work was partially funded through the EU project Bivalife
(FP7 KBBE, contract n 266157), the Poitou Charentes
Region and DPMA (Direction des p^eches maritimes et de
l’aquaculture, AESTU project). David Rubinsztein is aWellcome
Trust Prinicipal Research Fellow.This is the final published version. It first appeared at http://www.tandfonline.com/doi/full/10.1080/15548627.2015.1017188
A nuclear export signal within the structural Gag protein is required for prototype foamy virus replication
<p>Abstract</p> <p>Background</p> <p>The Gag polyproteins play distinct roles during the replication cycle of retroviruses, hijacking many cellular machineries to fulfill them. In the case of the prototype foamy virus (PFV), Gag structural proteins undergo transient nuclear trafficking after their synthesis, returning back to the cytoplasm for capsid assembly and virus egress. The functional role of this nuclear stage as well as the molecular mechanism(s) responsible for Gag nuclear export are not understood.</p> <p>Results</p> <p>We have identified a leptomycin B (LMB)-sensitive nuclear export sequence (NES) within the N-terminus of PFV Gag that is absolutely required for the completion of late stages of virus replication. Point mutations of conserved residues within this motif lead to nuclear redistribution of Gag, preventing subsequent virus egress. We have shown that a NES-defective PFV Gag acts as a dominant negative mutant by sequestrating its wild-type counterpart in the nucleus. Trans-complementation experiments with the heterologous NES of HIV-1 Rev allow the cytoplasmic redistribution of FV Gag, but fail to restore infectivity.</p> <p>Conclusions</p> <p>PFV Gag-Gag interactions are finely tuned in the cytoplasm to regulate their functions, capsid assembly, and virus release. In the nucleus, we have shown Gag-Gag interactions which could be involved in the nuclear export of Gag and viral RNA. We propose that nuclear export of unspliced and partially spliced PFV RNAs relies on two complementary mechanisms, which take place successively during the replication cycle.</p
Le paleoenvironnement vegetal des occupations humaines de la Grotte de Payre à la fin du Pleistocène moyen et au début du Pleistocène supérieur (Ardèche, France)
The Middle Paleolithic site named Payre is located in the south-east of France, in the Middle Rhone Valley, in the Mediterranean world. Since 1990, the excavations have yielded a sequence dated from the isotopic stages 7 to 5. The palynological study based on settlement levels from the isotopic stages 6 and 5 has provided us with information about the vegetal environment of the end of the Middle Pleistocene and the beginning of the Upper Pleistocene. When men came, the landscape was semi-forest and the climate was temperate with Mediterranean influences.[es] El emplazamiento arqueológico del Paleolítico Medio de Payre se sitúa al sureste de Francia, en el valle del Ródano, en el contexto mediterráneo actual. Las excavaciones que vienen llevándose a cabo desde 1990 presentan una secuencia fechada en los estadios isotópicos 7 al 5. El estudio palinológico de los niveles de ocupación de los estadios isotópicos 6 y 5 nos informan sobre el contexto vegetal del final del Pleistoceno Medio y de principios del Pleistoceno Superior. Los diferentes periodos climáticos se caracterizan por la predominancia de los taxones arbóreos como Quercus t. ilex y Buxus. El paisaje es a lo largo del diagrama, globalmente semi-abierto y el clima de tipo templado presenta influencias mediterráneas.
[fr] Le gisement paléolithique moyen de Payre est situé dans le sud-est de la France, dans la moyenne vallée du Rhône en contexte méditerranéen. Les fouilles, qui s'y déroulent depuis 1990, livrent une séquence datée des stades isotopiques 7 à 5. L'étude palynologique des niveaux d'occupation des stades isotopiques 6 et 5 nous informe sur le contexte végétal de la fin du Pléistocène moyen et du début du Pléistocène supérieur. Le paysage est, lors des diverses occupations humaines, globalement semi-ouvert et le climat de type tempéré sous influence méditerranéenne
Splitting games over finite sets
This paper studies zero-sum splitting games with finite sets of states. Players dynamically choose a pair of martingales {pt,qt}t, in order to control a terminal payoff u(p∞,q∞). A firstpartintroduces the notion of “Mertens-Zamir transform” of a real-valued matrix and use it to approximate the solution of the Mertens-Zamir system for continuous functions on the square [0, 1]2. A second part considers the general case of finite splitting games with arbitrary correspondences containing the Dirac mass on the current state: building on Laraki and Renault (2020), we show that the value exists by constructing non Markovian ε-optimal strategies and we characterize it as the unique concave-convex function satisfying two new conditions
Long information design
We analyze information design games between two designers with opposite preferences and a single agent. Before the agent makes a decision, designers repeatedly disclose public information about persistent state parameters. Disclosure continues until no designer wishes to reveal further information. We consider environments with general constraints on feasible information disclosure policies. Our main results characterize equilibrium payoffs and strategies of this long information design game and compare them with the equilibrium outcomes of games where designers move only at a single predetermined period. When information disclosure policies are unconstrained, we show that at equilibrium in the long game, information is revealed right away in a single period; otherwise, the number of periods in which information is disclosed might be unbounded. As an application, we study a competition in product demonstration and show that more information is revealed if each designer could disclose information at a predetermined period. The format that provides the buyer with most information is the sequential game where the last mover is the ex-ante favorite seller
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