Self-organized patterns of coexistence out of a predator-prey cellular automaton

We present a stochastic approach to modeling the dynamics of coexistence of prey and predator populations. It is assumed that the space of coexistence is explicitly subdivided in a grid of cells. Each cell can be occupied by only one individual of each species or can be empty. The system evolves in time according to a probabilistic cellular automaton composed by a set of local rules which describe interactions between species individuals and mimic the process of birth, death and predation. By performing computational simulations, we found that, depending on the values of the parameters of the model, the following states can be reached: a prey absorbing state and active states of two types. In one of them both species coexist in a stationary regime with population densities constant in time. The other kind of active state is characterized by local coupled time oscillations of prey and predator populations. We focus on the self-organized structures arising from spatio-temporal dynamics of the coexistence. We identify distinct spatial patterns of prey and predators and verify that they are intimally connected to the time coexistence behavior of the species. The occurrence of a prey percolating cluster on the spatial patterns of the active states is also examined.Comment: 19 pages, 11 figure

Emerging Ionic Soft Materials based on Deep Eutectic Solvents

PostprintIn the last five years, the use of deep eutectic solvents (DES) have been opening new perspectives towards the creation of novel ionic soft materials as alternatives to expensive ionic liquids. This Mini-Review highlights the progress and advances in soft ionic materials or gels, mostly composed by a DES immobilized within difference matrices, such as linear polymers, polymer networks, biopolymers, supramolecular compounds or organosilane networks. By taking advantage of the DES characteristics and properties in the solid state, this building system delivers a variety of tailor-made materials showing different functionalities (ionic conductivity, self-healing, stretchability and pH-responsiveness) and offers a way to circumvent drawbacks related to shaping and risk of leakage in many technological applications. In this context, we provide a judicious analysis of these emerging ionic soft materials, their properties and applications open in energy, (bio)electronics, drug delivery, analytical chemistry, and wastewater treatment. Perspectives and opportunities for future research directions on this blossoming field are also discussed.Liliana C. Tomé has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 745734. This work was supported by Marie Sklodowska-Curie Research and Innovation Staff Exchanges (RISE) project under the grant agreement No 823989 “IONBIKE”

O CD-ROM "Vamos fazer jornais escolares " : um contributo para a inserção da literacia dos media e das TIC nos currículos

Este texto apresenta uma investigação realizada em Portugal, cujos resultados apontam para o facto da produção de jornais escolares, por alunos do 2º e 3º Ciclo, contribuir para desenvolver a Literacia dos Media e a Educação para a Cidadania, bem como para promover a utilização da Tecnologias de Informação e Comunicação na sala de aula

cLFV processes and suppression of non-unitary mixing effects in low scale seesaw models

We examine the parameter space region of the inverse seesaw model that is consistent with neutrino oscillation data. We focus on the correlation between the current limits from the search of the $\mu\to e\gamma$ lepton flavour violating decay and the non-standard effects associated with the presence of new heavy neutrino states. Unlike what we would expect from an inverse seesaw model, we have found a parametrization for the mass matrices in which the rates of charged lepton flavour-violating processes are negligible. Additionally, we provide a model where the inverse seesaw is obtained naturally, and the mass matrices get this structure with negligible violation of the lepton flavour.Comment: 20 pages, 3 figures and 3 table

Dynamic critical exponents of the Ising model with multispin interactions

We revisit the short-time dynamics of 2D Ising model with three spin interactions in one direction and estimate the critical exponents $z,$ $\theta,$ $\beta$ and $\nu$. Taking properly into account the symmetry of the Hamiltonian we obtain results completely different from those obtained by Wang et al.. For the dynamic exponent $z$ our result coincides with that of the 4-state Potts model in two dimensions. In addition, results for the static exponents $\nu$ and $\beta$ agree with previous estimates obtained from finite size scaling combined with conformal invariance. Finally, for the new dynamic exponent $\theta$ we find a negative and close to zero value, a result also expected for the 4-state Potts model according to Okano et al.Comment: 12 pages, 9 figures, corrected Abstract mistypes, corrected equation on page 4 (Parameter Q

Mean-field analysis of the majority-vote model broken-ergodicity steady state

We study analytically a variant of the one-dimensional majority-vote model in which the individual retains its opinion in case there is a tie among the neighbors' opinions. The individuals are fixed in the sites of a ring of size $L$ and can interact with their nearest neighbors only. The interesting feature of this model is that it exhibits an infinity of spatially heterogeneous absorbing configurations for $L \to \infty$ whose statistical properties we probe analytically using a mean-field framework based on the decomposition of the $L$-site joint probability distribution into the $n$-contiguous-site joint distributions, the so-called $n$-site approximation. To describe the broken-ergodicity steady state of the model we solve analytically the mean-field dynamic equations for arbitrary time $t$ in the cases n=3 and 4. The asymptotic limit $t \to \infty$ reveals the mapping between the statistical properties of the random initial configurations and those of the final absorbing configurations. For the pair approximation ($n=2$) we derive that mapping using a trick that avoids solving the full dynamics. Most remarkably, we find that the predictions of the 4-site approximation reduce to those of the 3-site in the case of expectations involving three contiguous sites. In addition, those expectations fit the Monte Carlo data perfectly and so we conjecture that they are in fact the exact expectations for the one-dimensional majority-vote model

Neonatal Diagnosis of Prader-Willi Syndrome

A síndrome de Prader-Willi tem uma prevalência aproximada de 1:25000 nascimentos. No período neonatal há hipotonia severa, atraso de crescimento e dificuldade alimentar que persistem durante o primeiro ano de vida. O quadro clínico inicial contrasta com a bulimia que se evidencia mais tarde e que, não controlada, pode conduzir à obesidade mórbida. Descrevem-se as características clínicas, o diagnóstico genético e os cuidados específicos a ter na promoção da saúde a propósito de cinco crianças com síndrome de Prader Willi, cujo diagnóstico foi feito no período neonatal