Stability of nonlinear system using takagi-sugeno fuzzy models and hyper-rectangle of LMIs

This paper presents a theorem based on the hyper-rectangle defined by the closed set of the time derivatives of the membership functions of Takagi-Sugeno fuzzy systems. This result is also based on Linear Matrix Inequalities and allows the reduction of the conservatism of the stability analysis in the sense of Lyapunov. The theorem generalizes previous results available in the literature. © 2013 Brazilian Society for Automatics - SBA.

The dimensionality of ecological networks

How many dimensions (trait-axes) are required to predict whether two species interact? This unanswered question originated with the idea of ecological niches, and yet bears relevance today for understanding what determines network structure. Here, we analyse a set of 200 ecological networks, including food webs, antagonistic and mutualistic networks, and find that the number of dimensions needed to completely explain all interactions is small (< 10), with model selection favouring less than five. Using 18 high-quality webs including several species traits, we identify which traits contribute the most to explaining network structure. We show that accounting for a few traits dramatically improves our understanding of the structure of ecological networks. Matching traits for resources and consumers, for example, fruit size and bill gape, are the most successful combinations. These results link ecologically important species attributes to large-scale community structure. © 2013 Blackwell Publishing Ltd/CNRS.

Mixing Eucalyptus and Acacia trees leads to fine root over-yielding and vertical segregation between species

The consequences of diversity on belowground processes are still poorly known in tropical forests. The distributions of very fine roots (diameter <1 mm) and fine roots (diameter <3 mm) were studied in a randomized block design close to the harvest age of fast-growing plantations. A replacement series was set up in Brazil with mono-specific Eucalyptus grandis (100E) and Acacia mangium (100A) stands and a mixture with the same stocking density and 50 % of each species (50A:50E). The total fine root (FR) biomass down to a depth of 2 m was about 27 % higher in 50A:50E than in 100A and 100E. Fine root over-yielding in 50A:50E resulted from a 72 % rise in E. grandis fine root biomass per tree relative to 100E, whereas A. mangium FR biomass per tree was 17 % lower than in 100A. Mixing A. mangium with E. grandis trees led to a drop in A. mangium FR biomass in the upper 50 cm of soil relative to 100A, partially balanced by a rise in deep soil layers. Our results highlight similarities in the effects of directional resources on leaf and FR distributions in the mixture, with A. mangium leaves below the E. grandis canopy and a low density of A. mangium fine roots in the resource-rich soil layers relative to monospecific stands. The vertical segregation of resource-absorbing organs did not lead to niche complementarity expected to increase the total biomass production. © 2012 Springer-Verlag Berlin Heidelberg.

Interference of cage fish farm on diet, condition factor and numeric abundance on wild fish in a Neotropical reservoir

Historically, the ichthyofauna of large Brazilian rivers has been subject to anthropogenic interference, such as impoundments. Currently, cage fish farming systems are a new source of impact on aquatic ecosystems. The objective of this study was to characterise the impact of freshwater fish farms on the feeding of five species of Neotropical freshwater fish. Specimens of Astyanax altiparanae, Galeocharax knerii, Iheringicthys labrosus, Pimelodus maculatus and Plagioscion squamosissimus were sampled in areas around two systems of cage fish farming (CF), and two control areas (CT) that were not influenced by this activity. Results show that there were significant changes in the diet of trophic generalist species (A. altiparanae, P. maculatus and I. labrosus) accompanied by a related increase in the condition factor values of these species in cage areas. Trophic specialist species, such as the carnivorous fish species G. knerii and P. squamosissimus, presented small differences between the CF and CT areas with regard to diet and showed no differences in other analyses performed. In conclusion, cage fish farms can affect the natural diet of trophic generalist fish species, directly affecting the nutritional status (condition factor), where food wastes was found to be one of the principal items consumed by this trophic guild. Results indicate that these species are responsible for recycling a great quantity of organic matter transferred by this type of activity, which, along with local fishery activities, contribute to mitigation of associated processes of eutrophication. © 2013 Elsevier B.V.

O laboratório do artista - cientista

Pós-graduação em Artes - IA

Diversidade de morcegos (Chiroptera; Mammalia) em três áreas do noroeste paulista, com ênfase nas relações tróficas em Phyllostomidae

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Uso de recursos e padrão de co-ocorrência com insetos predadores em comunidades sub-tropicais de girinos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Similaridade ecológica em comunidades de girinos: o papel de componentes históricos (filogenéticos) e contemporâneos (ecológicos)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise morfológica e histoquímica do corpo gorduroso e dos túbulos de Malpighi de operárias adultas de Scaptotrigona postica (Latreille, 1807) (Hymenoptera, Apidae) tratadas com fipronil e ácido bórico

Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC

Macroalgas lóticas do Parque Nacional Chapada dos Veadeiros e arredores (GO): levantamento florístico e distribuição ecológica das comunidades

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A indústria de defesa brasileira: o setor de carros de combate e a Engesa

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Produção de café orgânico na região sul de Minas Gerais: eficiência econômica e energética

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Free trade and the development of sustainable agriculture in the Caribbean

Includes bibliography

O conhecimento sobre os recursos vegetais alimentares em bairros rurais no Vale do Paraíba-SP

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Antifúngicos naturais e sintéticos: estudo dos mecanismos de ação em sistema de infecção in vitro empregando cepas de Cryptococcus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)