An individual-based evolving predator-prey ecosystem simulation using a fuzzy cognitive map as the behavior model

This paper presents an individual-based predator-prey model with, for the first time, each agent behavior being modeled by a Fuzzy Cognitive Map (FCM), allowing the evolution of the agent behavior through the epochs of the simulation. The FCM enables the agent to evaluate its environment (e.g., distance to predator/prey, distance to potential breeding partner, distance to food, energy level), its internal state (e.g., fear, hunger, curiosity) with memory and choosing several possible actions such as evasion, eating or breeding. The FCM of each individual is unique and is the outcome of the evolution process throughout the simulation. The notion of species is also implemented in a way that species emerge from the evolving population of agents. To our knowledge, our system is the only one that allows modeling the links between behavior patterns and speciation. The simulation produces a lot of data including: number of individuals, level of energy by individual, choice of action, age of the individuals, average FCM associated to each species, number of species. This study investigates patterns of macroevolutionary processes such as the emergence of species in a simulated ecosystem and proposes a general framework for the study of specific ecological problems such as invasive species and species diversity patterns. We present promising results showing coherent behaviors of the whole simulation with the emergence of strong correlation patterns also observed in existing ecosystems

Polymorphic variants of genes involved in homocysteine metabolism in celiac disease

Celiac disease (CD) is a polygenic chronic enteropathy conferring an increased risk for various nutrient deficiency states. Hyperhomocysteinemia is a frequent finding in CD and may be related to the development of venous thrombosis, cardiovascular disease, and stroke in untreated CD patients. Recently, a possible excess in the frequency of the MTHFR c.677C>T (rs1801133) gene variant in CD patients was reported. The purpose of this study was to determine if there exist differences in the distribution of polymorphic variants of genes involved in homocysteine/methyl group metabolism between CD patients and the general population. A set of 10 gene polymorphisms (MTHFR rs1801133, MTR rs1805087, MTHFD1 rs2236225, MTRR rs1801394, CBS 844ins68, BHMT1 rs7356530 and rs3733890, BHMT2 rs526264 and rs625879, and TCN2 rs1801198) was tested in 134 patients with CD and 160 matched healthy controls. The frequency of the MTR rs1805087 GG genotype in CD patients was lower than in controls (0.01 and 0.06, respectively), although statistical significance was not achieved (P = 0.06). For the other analyzed polymorphisms, there was no evidence of difference in both allelic and genotypic distribution between cases and controls. The exhaustive Multifactor Dimensionality Reduction analysis revealed no combination of interactive polymorphisms predicting the incidence of CD. In contrast to the well-documented clinical observations of increased risks of vascular disease in patients with longstanding untreated CD, in our group of patients no significant association with CD was found for all tested polymorphic variants of genes involved in homocysteine metabolism. These findings should be replicated in studies with a larger sample size

La théorie évolutive de la connaissance. La relation phylogénétique de la représentation à l'objet

I examine the hypothesis that there exist synthetic a priori (innate), not available for the agent's control, Phylogenetically Acquired Representations (PAR), that have their origin in the causal, selective relations between the organism and some factors from its phylogenetic environment; the adaptative genesis of PAR would provide them the status of knowledge. The validity of this hypothesis is analysed in confrontation with the major tenets of the Modern Synthesis, such as the concept of the gene and of the genetic causation; the concept of the unit of selection; the concept of the species; the concepts of information and of innateness. I examine the metaphysical suppositions underlying taxonomical practice. I introduce the Relativist Theory of Evolution, inspired by the theory of evolutionary constructivism (by R. Lewontin) and by the Theory of Niche Construction (by J.Odling-Smee), breaking with externalist models of the relation environment/organism of the Modern Synthesis.Dans ma thèse j'examine l'hypothèse affirmant qu'il existe des représentations synthétiques a priori (innées), non accessibles au contrôle du sujet (Représentations Acquises Phylogénétiquement, RAP), et que ces représentations proviennent de relations causales sélectives entre l'organisme et certains facteurs de l'environnement phylogénétique; la genèse adaptative des RAP leur procurerait le statut de connaissance. La validité de cette hypothèse est analysée à travers l'étude critique des concepts principaux de la Théorie Synthétique de l'Evolution, tels que le concept du gène, de la causalité génétique, de l'unité de sélection, de l'espèce ; le concept de l'information ; le concept de l'inné. J'examine des suppositions métaphysiques sous-tendant la pratique taxinomique. Enfin, j'introduis la Théorie Relativiste de l'Evolution, inspirée par la théorie du constructivisme évolutif (R. Lewontin) et par la théorie de la construction de niche (Niche Construction de J.Odling-Smee), rompant avec la modélisation externaliste de la relation environnement/organisme propre à la Théorie Synthétique de l'Evolution.LYON3-Bibliothèques (693872102) / SudocLYON-BIU-LSH (693872101) / SudocSudocFranceF

Isolation and Antimicrobial Activity of Coumarin Derivatives from Fruits of Peucedanum luxurians Tamamsch

As a continuation of searching for phytoconstituents that act as promising agents for antimicrobial therapy, rare coumarins were isolated from fruits of Peucedanum luxurians and tested. In a first step, the content of major compounds in the aerial parts and fruits of P. luxurians were compared. The results clearly showed that the fruits with dichloromethane as a solvent yielded, in most cases, higher concentrations of almost all the analyzed coumarins than the aerial parts, with peucedanin detected as the most abundant compound with a concentration of 4563.94 ± 3.35 mg/100 g. Under this perspective, the dichloromethane extract from the fruits of P. luxurians was further submitted to high performance countercurrent chromatography with a mixture of n-hexane, ethyl acetate, methanol, and water 6:5:6:5 (v/v). Combination of HPCCC and prep-HPLC yielded 6',7'-dihydroxybergamottin (1), officinalin (2), stenocarpin isobutyrate (3), officinalin isobutyrate (4), 8-methoxypeucedanin (5), and peucedanin (6). Isolated compounds were tested against several Gram-positive and Gram-negative bacteria strains. 6',7'-Dihydroxybergamottin, peucedanin, and officinalin isobutyrate appeared to be the most active against all tested bacteria strains with minimum inhibitory concentration (MIC) values between 1.20 and 4.80 mg/mL. To the best of our knowledge, this is the first report about countercurrent isolation of mentioned coumarins, as well as the first information about their antimicrobial activity