Comparison of Different Parallel Implementations of the 2+1-Dimensional KPZ Model and the 3-Dimensional KMC Model

We show that efficient simulations of the Kardar-Parisi-Zhang interface growth in 2 + 1 dimensions and of the 3-dimensional Kinetic Monte Carlo of thermally activated diffusion can be realized both on GPUs and modern CPUs. In this article we present results of different implementations on GPUs using CUDA and OpenCL and also on CPUs using OpenCL and MPI. We investigate the runtime and scaling behavior on different architectures to find optimal solutions for solving current simulation problems in the field of statistical physics and materials science.Comment: 14 pages, 8 figures, to be published in a forthcoming EPJST special issue on "Computer simulations on GPU

The Harris-Luck criterion for random lattices

The Harris-Luck criterion judges the relevance of (potentially) spatially correlated, quenched disorder induced by, e.g., random bonds, randomly diluted sites or a quasi-periodicity of the lattice, for altering the critical behavior of a coupled matter system. We investigate the applicability of this type of criterion to the case of spin variables coupled to random lattices. Their aptitude to alter critical behavior depends on the degree of spatial correlations present, which is quantified by a wandering exponent. We consider the cases of Poissonian random graphs resulting from the Voronoi-Delaunay construction and of planar, ``fat'' $\phi^3$ Feynman diagrams and precisely determine their wandering exponents. The resulting predictions are compared to various exact and numerical results for the Potts model coupled to these quenched ensembles of random graphs.Comment: 13 pages, 9 figures, 2 tables, REVTeX 4. Version as published, one figure added for clarification, minor re-wordings and typo cleanu

Influência de fatores ambientais na distribuição de famílias de insetos aquáticos em rios no sul do Brasil

Os rios neotropicais sofrem os efeitos das ações humanas. Medidas conservacionistas, pela escassez de estudos na região e do conhecimento límnico, baseiam-se em dados referentes a outras regiões, sendo muitas vezes ineficazes pela inobservância das diferenças nas respostas das comunidades aquáticas às variáveis ambientais em escalas distintas. Este estudo teve como objetivos: conhecer a riqueza de insetos aquáticos em uma bacia neotropical; verificar qual a influência das variáveis ambientais na distribuição das famílias de insetos aquáticos em quatro tributários dessa bacia e observar se o padrão de distribuição das famílias de insetos aquáticos varia entre as ordens dos rios ou entre microbacias, de acordo com a influência de variáveis ambientais e espaciais. Foi encontrado um total de 9.135 indivíduos distribuídos em 26 famílias de macroinvertebrados. A estrutura das comunidades foi distinta entre as microbacias. As famílias de insetos aquáticos foram influenciadas pelas variáveis ambientais e espaciais diferentes em cada microbacia

Macroinvertebrate-based index of biotic integrity for protection of streams in west-central Mexico

The water and habitat quality of many streams in west-central Mexico are influenced by municipal and industrial effluent, as well as water diversion for irrigation, livestock, and deforestation. Restoration efforts have been hampered by a lack of clear standards against which to judge the degree and trend in environmental degradation. We describe the development and characteristics of a macroinvertebrate-based index of biotic integrity (IBI) designed to provide such standards. Eight metrics chosen a priori comprised the IBI: catch per unit effort, generic richness, % Ephemeroptera-Plecoptera-Trichoptera genera, % Chironomidae individuais, Hilsenhoff Biotic Index, % depositional individuais, % predator individuais, and % gatherer genera. Each metric distinguished sites with minimum or moderate human influence from sites with severe influence. The IBI was developed with data from 27 sites and validated with 6 others. Values from the development data set correlated well with the measures of human influence based on qualitative assessment of habitat and water quality (Pearson's r = 0.86). IBI values for 7 sites on Río Ayuquila corresponded with a documented longitudinal pattern of human influence and the existing fish-based IBI (Pearson's r = 0.87). This macroinvertebrate IBI shows promise for developing biological standards, facilitating long-term monitoring, and improving ecological integrity of streams in west-central Mexico

Macroinvertebrate-based index of biotic integrity for protection of streams in west-central Mexico

The water and habitat quality of many streams in west-central Mexico are influenced by municipal and industrial effluent, as well as water diversion for irrigation, livestock, and deforestation. Restoration efforts have been hampered by a lack of clear standards against which to judge the degree and trend in environmental degradation. We describe the development and characteristics of a macroinvertebrate-based index of biotic integrity (IBI) designed to provide such standards. Eight metrics chosen a priori comprised the IBI: catch per unit effort, generic richness, % Ephemeroptera-Plecoptera-Trichoptera genera, % Chironomidae individuais, Hilsenhoff Biotic Index, % depositional individuais, % predator individuais, and % gatherer genera. Each metric distinguished sites with minimum or moderate human influence from sites with severe influence. The IBI was developed with data from 27 sites and validated with 6 others. Values from the development data set correlated well with the measures of human influence based on qualitative assessment of habitat and water quality (Pearson's r = 0.86). IBI values for 7 sites on Río Ayuquila corresponded with a documented longitudinal pattern of human influence and the existing fish-based IBI (Pearson's r = 0.87). This macroinvertebrate IBI shows promise for developing biological standards, facilitating long-term monitoring, and improving ecological integrity of streams in west-central Mexico

Structures and functions associated with the group of mammalian lectins containing collagen-like sequences

AbstractThe number of proteins found in body fluids and at cell surfaces, which are known to display carbohydrate-binding properties, continues to increase rapidly. In these proteins, in addition to a domain associated with lectin properties, one or more, non-lectin domains are present. It is possible that binding of sugar residues by the lectin domain may be important in triggering a variety of recognition and clearance mechanisms via the non-lectin domains. The group of lectins containing collagen-like sequences may provide some insight into structure/function relationships of the different domains in view of the well defined structures already available for several of these molecules