Scale-free network topology and multifractality in weighted planar stochastic lattice

We propose a weighted planar stochastic lattice (WPSL) formed by the random sequential partition of a plane into contiguous and non-overlapping blocks and find that it evolves following several non-trivial conservation laws, namely $\sum_i^N x_i^{n-1} y_i^{4/n-1}$ is independent of time $\forall \ n$, where $x_i$ and $y_i$ are the length and width of the $i$th block. Its dual on the other hand, obtained by replacing each block with a node at its center and common border between blocks with an edge joining the two vertices, emerges as a network with a power-law degree distribution $P(k)\sim k^{-\gamma}$ where $\gamma=5.66$ revealing scale-free coordination number disorder since $P(k)$ also describes the fraction of blocks having $k$ neighbours. To quantify the size disorder, we show that if the $i$th block is populated with $p_i\sim x_i^3$ then its distribution in the WPSL exhibits multifractality.Comment: 7 pages, 8 figures, To appear in New Journal of Physics (NJP

Simulations of viscous shape relaxation in shuffled foam clusters

We simulate the shape relaxation of foam clusters and compare them with the time exponential expected for Newtonian fluid. Using two-dimensional Potts Model simulations, we artificially create holes in a foam cluster and shuffle it by applying shear strain cycles. We reproduce the experimentally observed time exponential relaxation of cavity shapes in the foam as a function of the number of strain steps. The cavity rounding up results from local rearrangement of bubbles, due to the conjunction of both a large applied strain and local bubble wall fluctuations

Impact of grazing management on forage qualitative characteristics: a review.

The main system for feeding cattle in Brazil is the forage-based. It happens due to low cost and high potential of forage production, which can be widely explored in a tropical climate country. Although, the nutritive value of the forage oscillates according to the grazing management. The success in production is related to the three main stages: herbage growth, consumption by grazing animals and conversion into animal product, maximizing profitability while providing sustainability. Thus, the objective with this literature review is to address detailed information on how grazing management can affect qualitative indicators of forage plants

Nitrous oxide emissions in eucalyptus production under monoculture and integrated systems in Sinop /MT.

The main cause of climate change is the increase in greenhouse gases (GHG) emissions caused by activities such as agriculture, and nitrous oxide (N2O) is one of the main gases emitted by these activities. Therefore, the objective of this study was to evaluate N2O emissions of Eucalyptus urograndis under monoculture and integrated production systems

Nitrous oxide fluxes in an integrated crop-livestock-forest system in Sinop-MT.

The objective of this study was to evaluate the mitigation potential of crop-livestock-forest integration system (ICLF) or monoculture forest, farming and grazing, check the seasonal differences in emissions between them and the effect of management operations of cultures on N2O fluxes

Exponential Distribution of Locomotion Activity in Cell Cultures

In vitro velocities of several cell types have been measured using computer controlled video microscopy, which allowed to record the cells' trajectories over several days. On the basis of our large data sets we show that the locomotion activity displays a universal exponential distribution. Thus, motion resulting from complex cellular processes can be well described by an unexpected, but very simple distribution function. A simple phenomenological model based on the interaction of various cellular processes and finite ATP production rate is proposed to explain these experimental results.Comment: 4 pages, 3 figure

Perdas na silagem de grão de milho triturado reidratado contendo glicerina bruta e inoculante microbiano

Avaliou-se o efeito da inclusão de diferentes níveis de glicerina bruta, com ou sem inoculante microbiano sobre as perdas na silagem de grão de milho triturado e reidratado. O grão seco de milho moído, inoculado ou não com inoculante microbiano, foi reidratado com água e glicerina bruta em diferentes níveis para manter o teor de umidade em 32,5%, conferindo a adição de 0; 7,5; 15,0 e 22,5% de glicerina bruta (matéria natural) e ensilado em silos experimentais de PVC. O experimento foi conduzido em esquema fatorial (2x4x6) segundo o delineamento inteiramente casualizado com três repetições por tratamento. As perdas por efluente aumentaram linearmente com a adição de níveis crescentes de glicerina bruta, independente do uso de inoculante e também nos períodos de fermentação. Porém, as perdas por gás reduziram linearmente e tiveram resposta quadrática com o aumento da inclusão de glicerina bruta para os tratamentos sem e com in oculante. As perdas de matéria seca totais aumentaram com o incremento nos níveis de glicerina bruta, independente do inoculante. A inclusão de 7,5% de glicerina bruta com inoculante propicia as menores perdas de matéria seca total na silagem de grão de milho triturado e reidratado

Cell adhesion and cortex contractility determine cell patterning in the Drosophila retina

Hayashi and Carthew (Nature 431 [2004], 647) have shown that the packing of cone cells in the Drosophila retina resembles soap bubble packing, and that changing E- and N-cadherin expression can change this packing, as well as cell shape. The analogy with bubbles suggests that cell packing is driven by surface minimization. We find that this assumption is insufficient to model the experimentally observed shapes and packing of the cells based on their cadherin expression. We then consider a model in which adhesion leads to a surface increase, balanced by cell cortex contraction. Using the experimentally observed distributions of E- and N-cadherin, we simulate the packing and cell shapes in the wildtype eye. Furthermore, by changing only the corresponding parameters, this model can describe the mutants with different numbers of cells, or changes in cadherin expression.Comment: revised manuscript; 8 pages, 6 figures; supplementary information not include

Attractants for automated emission measurement (Greenfeed®) in pasture-based systems.

This study aimed to evaluate the frequency and intensity of GreenFeed (GF) use by Nellore steers using different attractants in pastures of integrated systems. The attractant protein supplement and Tifton bermudagrass pelleted hay flavored with vanilla were evaluated over a period of 15 days. The pelleted hay stimulated the animals to stay longer in the equipment (24.23 s), with 8% more visits in intervals longer than 30 s in contrast to protein supplement. This indicates that pelleted hay flavored with vanilla is a potential attractant to encourage Nellore steers to visit GF in grazing systems

Perfil fermentativo da silagem de Brachiaria brizantha cv. Piatã com diferentes aditivos

A possibilidade de uso das gramíneas na forma de silagem, principalmente do gênero das Brachiariasp., deveriam ser mais estudadas no Brasil, que possui grandes áreas de pastagens implantadas com estas espécies. Contudo, são escassos os trabalhos na literatura com uso de aditivos para estas gramíneas. Nesse contexto, objetivou-se avaliar o perfil fermentativo da silagem de Brachiaria brizantha cv. Piatã tratada com diferentes aditivos. A forrageira foi colhida e ensilada em silos experimentais de PVC. O delineamento experimental utilizado foi inteiramente casualizado, fornecendo 4 repetições por tratamento, sendo os cinco tratamentos os diferentes aditivos: T1 ? controle; T2 ? inoculante microbiano SiloMax Centurium (Matsuda); T3 ? inoculante ênzimo-microbianoSil All C4 (Alltech do Brasil); T4 ? fubá de milho (10% na matéria natural) e T5 ? glicerina bruta (10% na matéria natural), totalizando 20 silos experimentais. Foram observados menores valores de pH de 4,22 e 4,29 e, maiores valores de acidez titulável de 53,00 e 52,81 mL de NaOH 0,1N para silagens contendo fubá de milho e glicerina bruta, respectivamente. Recomenda-se ainclusão de 10% de fubá de milho e glicerina bruta na matéria natural na ensilagem de Piatã, pois promove melhor perfil fermentativo