12 research outputs found
Climate change impacts on freshwater fishes: a Patagonian perspective
The fish fauna of Patagonian lakes comprises a small, unique group of native species and several exotic ones. The consequences of environmental changes for Patagonian fish populations vary according to the physiology of the species considered. Several previously predicted facts such as extirpations, extinctions, and translocations have occurred and human actions such as transport, introduction, and stocking of exotic species suggest a more complex future. We discuss the historical biogeography of Patagonian freshwater ichthyofauna to help us better understand their present adaptations and physiological ecology. We also address potential interactions between climate change and processes such as migration, species introductions, and invasions. There is still much to learn from Patagonian fishes to comprehend how these species will endure environmental changes.Fil: Becker, Leandro Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales.; ArgentinaFil: Crichigno, Sonia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales.; ArgentinaFil: Cussac, Victor Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales.; Argentin
Simulation of multi-radio multi-channel 802.11-based mesh networks in ns-3
In the context of wireless network simulation, many simulators are capable of evaluating the performance of single-channel network protocols, but they need many modifications to be able to simulate multi-radio multi-channel networks. We address the problem of simulating channel assignment protocols for multi-radio wireless mesh networks in ns-3 simulator, providing the essential steps needed to simulate a channel assignment protocol. In addition, we explain the details of simulating the Semi-dynamic Interference aware Channel Assignment (SICA) protocol as an example. We use SICA as a reference to address the challenges of validating and verifying the simulation model. To validate the channel assignment model in SICA, we use mathematical validation based on Markov chains. Furthermore, we propose a novel automated test module to verify the simulation process.This work has been partially supported by the Spanish Government under project TEC2012-32354 (Plan Nacional I+D) and TIN2013-47272-C2-2, and by the Catalan Government (SGR-2014-1173 and SGR-2014-881
Phenotypic diversity, population structure and stress protein-based capacitoring in populations of Xeropicta derbentina, a heat-tolerant land snail species
The shell colour of many pulmonate land snail species is highly diverse. Besides a genetic basis, environmentally triggered epigenetic mechanisms including stress proteins as evolutionary capacitors are thought to influence such phenotypic diversity. In this study, we investigated the relationship of stress protein (Hsp70) levels with temperature stress tolerance, population structure and phenotypic diversity within and among different populations of a xerophilic Mediterranean snail species (Xeropicta derbentina). Hsp70 levels varied considerably among populations, and were significantly associated with shell colour diversity: individuals in populations exhibiting low diversity expressed higher Hsp70 levels both constitutively and under heat stress than those of phenotypically diverse populations. In contrast, population structure (cytochrome c oxidase subunit I gene) did not correlate with phenotypic diversity. However, genetic parameters (both within and among population differences) were able to explain variation in Hsp70 induction at elevated but non-pathologic temperatures. Our observation that (1) population structure had a high explanatory potential for Hsp70 induction and that (2) Hsp70 levels, in turn, correlated with phenotypic diversity while (3) population structure and phenotypic diversity failed to correlate provides empirical evidence for Hsp70 to act as a mediator between genotypic variation and phenotype and thus for chaperone-driven evolutionary capacitance in natural populations