Situation du criquet marocain "Dociostaurus maroccanusThunb., 1815" par rapport aux différentes espèces acridiennes : morphométrie et capacités de déplacements

La faculté de déplacements par vol des criquets adultes permet aux populations acridiennes de se déplacer sur de grandes distances et de rechercher des habitats dont les caractéristiques répondent le mieux à leurs besoins. Dans le présent travail, nous étudions des traits morphologiques d’un certain nombre d’espèces migratrices et non migratrices de deux sous-familles d’Acrididae (Oedipodinae et Gomphocerinae). Par les mesures de différentes parties du corps des criquets adultes, nous avons pu situer le criquet marocain "Dociostaurus maroccanus Thunb., 1815" par rapport à l’ensemble des espèces étudiées. Cette étude morphométrique, souligne bien la liaison existante entre les capacités des déplacements des criquets et leurs traits morphologiques. Ainsi, on note bien une importante distinction morphologique entre l’espèce migratrice Locusta migratoria et les espèces non migratrices. Dociostaurus maroccanus se montre capable d’effectuer des déplacements importants, mais elle ne peut être migratrice comme Locusta migratoria.Mots-clés : Morphométrie, capacités de déplacements, traits morphologiques, Criquet marocain, espèces migratrices

Integrated optimization of strategic and tactical planning decisions in forestry

The traditional approach to plan the forest products value chain using a combination of sequential and hierarchical planning phases leads to suboptimal solutions. We present an integrated planning model to support forest planning on the long term with anticipation of the impacts on the economic and logistic activities in the forest value chain on a shorter term, and we propose a novel optimization approach that includes acceleration strategies to efficiently solve large-scale practical instances of this integrated planning problem. Our model extends and binds the models implemented in two solver engines that have developed in previous work. The first system, called Logilab, allows for defining and solving value chain optimization problems. The second system, called Silvilab, allows for generating and solving strategic problems. We revisit the tactical model in Logilab and we extend the strategic model in Silvilab so that the integrated planning problem can be solved using column generation decomposition with the subproblems formulated as hypergraphs and solved using a dynamic programing algorithm. Also, a new set of spatial sustainability constraints is considered in this model. Based on numerical experiments on large-scale industrial cases, the integrated approach resulted in up to 13% profit increase in comparison with the non-integrated approach. In addition, the proposed approach compares advantageously with a standard LP column generation approach to the integrated forest planning problem, both in CPU time (with an average 2.4 factor speed-up) and in memory requirement (with an average reduction by a factor of 20)

Normalized equilibrium in Tullock rent seeking game

International audienceGames with Common Coupled Constraints represent manyreal life situations. In these games, if one player fails tosatisfy its constraints common to other players, then theother players are also penalised. Therefore these games canbe viewed as being cooperative in goals related to meetingthe common constraints, and non cooperative in terms ofthe utilities. We study in this paper the Tullock rent seekinggame with additional common coupled constraints. We havesucceded in showing that the utilities satisfy the property ofdiagonal strict concavity (DSC), which can be viewed asan extention of concavity to a game setting. It not onlyguarantees the uniqueness of the Nash equilibrium but also of the normalized equilibrium

Nuclear power and coastal birds: predicting the ecological consequences of warm-water outflows

Local alteration of species abundance in natural communities due to anthropogenic impacts may have secondary, cascading effects on species at higher trophic levels. Such effects are typically hard to single out due to their ubiquitous nature and, therefore, may render impact assessment exercises difficult to undertake. Here we describe how we used empirical knowledge together with modelling tools to predict the indirect trophic effects of a future warm-water outflow on populations of shorebirds and wildfowl. Of the main potential benthic prey used by the birds in this instance, the clam Macoma balthica was the only species suspected to be adversely affected by a future increase of temperature. Various scenarios of decreases in prey energy content, simulating various degrees of temperature increase, were tested using an individual-based model, MORPH, in order to assess the effects on birds. The survival and body condition of eight of the 10 bird species modelled, dunlin, ringed plover, turnstone, redshank, grey plover, black-tailed godwit, oystercatcher and shelduck were shown to be not influenced even by the most conservative prey reduction scenarios. Most of these species are known to feed primarily on polychaete worms. For the few bivalve-feeding species, the larger size-classes of polychaete worms were predicted to be a sufficient alternative food. Only knot was predicted to have a lower survival under the two worst case scenario of decreased M. balthica energy content. We believe that this is the first time such predicted cascade effects from a future warm-water outflow have been shown

Bounded Generalized Kelly Mechanism for Multi-Tenant Caching in Mobile Edge Clouds

Mobile edge computing represents a promising paradigm for 5G telecommunication operators. Among various services that can be provided by this technology, cloud edge caching is receiving increasing attention by network providers. By using cloud technology, in particular, the memory space of mobile edge network devices can be provisioned to OTT content providers over specific areas. They can use cache space in order to serve their customers with improved quality of service figures. We study a competitive scheme where contents are dynamically stored in the edge memory deployed by the network provider. OTT content providers are subject to Kelly mechanism with generalized cost and with bounded strategy set. After proving the uniqueness of the Nash equilibrium of such scheme, a simple bisection algorithm for its calculation is provided. Numerical results characterize the Nash equilibrium