Contrasting predation services of predator and omnivore diversity mediated by invasive ants in a tropical agroecosystem

Invasive natural enemies are known to either strengthen or weaken the suppression of herbivorous arthropods. However, the impact of invasive species on the predation service provided by natural enemy diversity remains largely unexplored. Here, we tease apart the roles of invasive ants as providers of a predation service and a potential disservice, i.e. reducing the diversity of natural enemies. In mango orchards on Reunion Island, we evaluated the predation service in 20 open fields by simultaneously monitoring the predation on bait eggs and arthropod communities in two strata: the ground surface and the mango tree canopy. Our results show that the predation on bait eggs was limited to the ground surface. This stratum is dominated by three invasive omnivorous ants: Pheidole megacephala and Solenopsis geminata strongly increased the predation rate of bait eggs, whereas Brachymyrmex cordemoyi was responsible for only a small decrease in predation rate. Predation rate was positively related to predator species richness, and was negatively related to omnivore species richness. The negative relationship between the predation rate and omnivore species richness is caused by the most dominant invasive ant, P. megacephala, which reduces omnivore richness and seems to strongly prey on eggs. This study demonstrates, for the first time, the distinct influence of the diversity of two trophic groups on the predation service and how these effects can be mediated by invasive ant species. (Résumé d'auteur

Symmetry in temporal logic model checking

Temporal logic model checking involves checking the state-space of a model of a system to determine whether errors can occur in the system. Often this involves checking symmetrically equivalent areas of the state-space. The use of symmetry reduction to increase the efficiency of model checking has inspired a wealth of activity in the area of model checking research. We provide a survey of the associated literature

Replication and Abstraction: Symmetry in Automated Formal Verification.

This article surveys fundamental and applied aspects of symmetry in system models, and of symmetry reduction methods used to counter state explosion in model checking, an automated formal verification technique. While covering the research field broadly, we particularly emphasize recent progress in applying the technique to realistic systems, including tools that promise to elevate the scope of symmetry reduction to large-scale program verification. The article targets researchers and engineers interested in formal verification of concurrent systems

Mireille aux Arènes d’Arles

Transcript of MIREILLE AUX ARÈNES D'ARLES by Gustave Derepas, appearing in LA VIE PROVENÇALE, juillet 1899, pp. 197–198

Controle genetique de la transmission de plastes d'origine paternelle chez Petunia hybrida Hort

SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : T 78629 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

L’art à l’école primaire

Derepas G. L’art à l’école primaire. In: La revue pédagogique, tome 21, Juillet-Décembre 1892. pp. 1-10

L’art à l’école primaire

Derepas G. L’art à l’école primaire. In: La revue pédagogique, tome 21, Juillet-Décembre 1892. pp. 1-10

Polarisation et transfert de charge dans les sytèmes cation métallique-molécules (développement de potentiels modèles)

Ce travail porte sur le développement de potentiels modèles permettant de décrire les interactions dans les sytèmes cation métallique-molécules afin, ultérieurement, d'étudier leurs propriétés par des calculs de dynamique moléculaire. Cette étude présente des intérêts non seulement pour des problèmes "environnementaux" mais aussi pour interpréter des expériences sur des petits agrégats en phase gazeuse. Pour des cations "classiques", c'est à dire pour des systèmes où l'interaction cation métallique-molécules peut être décrite par des interactions "classiques" (électrostatique et polarisation), nous traitons maintenant la polarisation non seulement comme un terme à n-corps mais aussi en tenant compte de l'autocohérence sur le champ électrique et des interactions moment induit-moment induit. Ce traitement, plus complet, de l'énergie de polarisation, n'est pas sans effet à la fois sur l'énergétique et sur les structures des systèmes étudiés...This research work aims at developing model potentials for describing metal cation-molecules systems, in order to study them in the near future with molecular dynamic simulations. These systems are involved in a lot of environmental or biological processes. They are also useful to understand experiments on small clusters in the gas phase, such as the ones performed at the C.E.A. For cations for which the main interaction, namely the metal cation-molecule interaction, can be interpreted by a classical term (electrostatic and polarisation), the polarisation term is still a many-body term but is now included with a back-polarisation contribution (i.e. self consistent electric field and induced dipole interactions). This enhanced treatment of the polarisation energy affects both the energetic and the structures. The Mq+(H2O)n, n=1,9 systems we have chosen are the one with M=Na, Cs, Ca, Ba, La and Lu. The minima of the PES for these systems have been obtained with the Monte Carlo growth method...ORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF