Dynamic Models for International Environmental Agreements

In this paper we develop a model to analyze, in a dynamic framework, how countries join international environmental agreements (IEAs). In the model, where countries suffer from the same environmental damage as a result of the total global emissions, a non-signatory country decides its emissions by maximizing its own welfare, whereas a signatory country decides its emissions by maximizing the aggregate welfare of all signatory countries. Signatory countries are assumed to be able to punish the non-signatories at a cost. When countries decide on their pollution emissions they account for the evolution of the pollution over time. Moreover, we propose a mechanism to describe how countries reach a stable IEA. The model is able to capture situations with partial cooperation in an IEA stable over time. It also captures situations where all countries participate in a stable agreement, or situations where no stable agreement is feasible. When more than one possibility coexists, the long-term outcome of the game depends on the initial conditions (i.e. the size of the initial group of signatory countries and the pollution level).International Environmental Agreements, Non-Cooperative Dynamic Game, Coalition Stability

Cooperating firms in inventive and absorptive research

We consider a duopoly competing in quantity, where firms can invest in both innovative and absorptive R&D to reduce their unit production cost, and where they benefit from free R&D spillovers between them. We analyze the case where firms act non cooperatively and the case where they cooperate by forming a research joint venture. We show that, in both modes of play, there exists a unique symmetric solution. We find that the investment in innovative R&D is always higher than in absorptive R&D. We also find that the value of the learning parameter has almost no impact on innovative R&D, firms profits, consumer's surplus and social welfare. Finally, differences in investment in absorptive research and social welfare under the two regimes are in opposite directions according to the importance of the free spillover.Innovative R&D; Absorptive R&D; Learning Parameter; Spillover; Research Joint Venture

Control in a dissipative environment: the example of a Cope rearrangement

International audienceIn this work, we present optimal control calculations in a dissipative. environment TO this end, the auxiliary density matrix, method describing the dissipative. quantum dynamics is combined. With,optimal Control theory. The resulting approach, which is nonperturbative in the laser system interaction, is applied to model the control; of Cope's isomerization of the methyl-cyclopentadienylcarboxylate dimer, described as the motion along a one-dimensional reaction path. The construction of the reaction path model as well as the dipole moments: required for the laser interaction are obtained from DFT quantum chemistry calculations. As a main result: we show that the proposed methodology, which includes the environment at the design stage of the control, leads to control fields which can react on dissipative effects during the dynamics and lead to an increased control objective, as compared to control fields obtained Without dissipation. The chosen example is analyzed in detail, and the physical mechanisms of the control under dissipation are elucidated

Contribution to the study of semiochemical slow release formulations. Development of flash chromatographic methods

Peer reviewe

Cooperating firms in inventive and absorptive research

We consider a duopoly competing in quantity, where firms can invest in both innovative and absorptive R&D to reduce their unit production cost, and where they benefit from free R&D spillovers between them. We analyze the case where firms act non cooperatively and the case where they cooperate by forming a research joint venture. We show that, in both modes of play, there exists a unique symmetric solution. We find that the investment in innovative R&D is always higher than in absorptive R&D. We also find that the value of the learning parameter has almost no impact on innovative R&D, firms profits, consumer's surplus and social welfare. Finally, differences in investment in absorptive research and social welfare under the two regimes are in opposite directions according to the importance of the free spillover

Cooperating firms in inventive and absorptive research

We consider a duopoly competing in quantity, where firms can invest in both innovative and absorptive R&D to reduce their unit production cost, and where they benefit from free R&D spillovers between them. We analyze the case where firms act non cooperatively and the case where they cooperate by forming a research joint venture. We show that, in both modes of play, there exists a unique symmetric solution. We find that the investment in innovative R&D is always higher than in absorptive R&D. We also find that the value of the learning parameter has almost no impact on innovative R&D, firms profits, consumer's surplus and social welfare. Finally, differences in investment in absorptive research and social welfare under the two regimes are in opposite directions according to the importance of the free spillover

Development of natural semiochemical slow-release formulations as biological control devices

peer reviewedSemiochemicals – informative molecules used in insect-insect or plant-insect interactions – have been widely considered within various integrated pest management (IPM) strategies. In the present work, two sesquiterpenoids, E-β-farnesene and E-β-caryophyllene, were formulated for their properties as aphid enemy attractants. E-β-farnesene, the alarm pheromone of many aphid species, was also identified as a kairomone by attracting aphid predators and parasitoids. E-β-caryophyllene was identified as a potential component of the aggregation pheromone of the Asian ladybird, Harmonia axyridis Pallas, another aphid predator. The two products were purified from essential oils of Matricaria chamomilla L. (Asteraceae) and Nepeta cataria L. (Lamiaceae), respectively. Natural and biodegradable formulations were then investigated in order to deliver these molecules on crop fields for a long period of time as biological control devices. Due to their sensitivity to oxidation, both sesquiterpenes needed to be protected from oxygen degradation. For this purpose, alginate – hydrophilic matrix with low oxygen permeability – was used as polymer for the formulations: the main objective was to deliver semiochemicals in the air in a controlled way. Consequently, a careful selection of alginates was realised. Formulated beads showed different structural and encapsulation properties depending on various formulation factors. Alginate formulations were characterised by texturometry and by confocal microscopy in order to observe the distribution of semiochemicals in alginate network. The last step of alginate bead characterisation consisted in studying release rate of semiochemicals in laboratory-controlled conditions by optimised volatile collection system and validated fast GC analytical procedures Finally, the efficiency of formulations as aphid predator (Syrphidae species) and parasitoid (Aphidius ervi) attractants was demonstrated by field trapping and olfactometry experiments.SOLAPHI

Efficiency of spiramycin and tylosin for the treatment of mycoplasmosis in chickens experimentally inf ected by Mycoplasma gallisepticum

Des poulets exempts d’organismes pathogènes spécifiés âgés de 3 semai nes sont inoculés par voie intratracheale avec une souche virulente de Mycoplasma gallisepticum R-P10. A partir du 4' jour après inoculation, les oiseaux reçoivent de la spiramycine selon trois posologies différentes ou de la tylosine pendant 2 ou 3 jours consécutifs. Les résultats montrent que les symptômes respiratoires et les lésions des oiseaux traités sont moins sévères que ceux des oiseaux non traités. La croissance des animaux est améliorée par les différents traitements. Les indices de réisolement de MG sont nettement réduits chez les oiseaux traités mais MG est réisolé dans tous les groupes 27 jours après inoculation.Three week-old specific pathogen free chickens were intratracheally inoculated with a virulent strain of Mycoplasma gallisepticum MG R-P10. From the fourth day after inoculation, birds were given spiramycin at three different doses or tylosin for two or three consecutive days. The results showed that respiratory symptoms and lesions of treated birds were less severe than those of infected non treated chickens. The growth rate was improved by the different medications. The MG recovery scores were markedly reduced in treated birds but MG could be reisolated from all different groups at 27 days post inoculation