Food Chemistry: Food quality and new analytical approaches

Peer Reviewe

Avaliação dos impactes ambientais de sistemas de produção agrícola alternativos no Baixo Mondego

O objectivo principal deste trabalho centra-se em avaliar os impactes ambientais de dois sistemas de produção agrícola na cultura do milho – Sementeira Directa (SD) e Modo de Produção Biológico (MPB) - na região do Baixo Mondego, Portugal. Durante o estudo, um programa de computador AMBITEC-AGRO - sistema da avaliação do impacto ambiental da tecnologia agropecuária foi utilizado após a adaptação do mesmo à realidade Portuguesa. Um inquérito foi preparado e apresentado aos produtores que aplicavam a(s) tecnologia(s) afim de obter informações sobre o impacte das mesmas quer na parcela ou na região. Os resultados foram recolhidos e inseridos posteriormente no programa afim de proceder à avaliação dos impactes ambientais. Os resultados principais mostram que ambos os sistemas de produção indicam um impacte positivo, com +2.22 para a SD e +2.07 para MPB numa escala de -15 a +15. O software utilizado para avaliação do impacte é de fácil aplicação e pode ser extremamente útil na eco-certificação futura das explorações agrícolas, fornecendo uma ferramenta para avaliar a sua sustentabilidade

The role of Dark Matter interaction in galaxy clusters

We consider a toy model to analyze the consequences of dark matter interaction with a dark energy background on the overall rotation of galaxy clusters and the misalignment between their dark matter and baryon distributions when compared to {\Lambda}CDM predictions. The interaction parameters are found via a genetic algorithm search. The results obtained suggest that interaction is a basic phenomenon whose effects are detectable even in simple models of galactic dynamics.Comment: RevTeX 4.1, 5 pages, 3 figure

X-ray method to study temperature-dependent stripe domains in MnAs/GaAs(001)

MnAs films grown on GaAs (001) exhibit a progressive transition between hexagonal (ferromagnetic) and orthorhombic (paramagnetic) phases at wide temperature range instead of abrupt transition during the first-order phase transition. The coexistence of two phases is favored by the anisotropic strain arising from the constraint on the MnAs films imposed by the substrate. This phase coexistence occurs in ordered arrangement alternating periodic terrace steps. We present here a method to study the surface morphology throughout this transition by means of specular and diffuse scattering of soft x-rays, tuning the photon energy at the Mn 2p resonance. The results show the long-range arrangement of the periodic stripe-like structure during the phase coexistence and its period remains constant, in agreement with previous results using other techniques.Comment: 4 pages, 4 figures, submitted to Applied Physics Letter

A Self-Adaptive Penalty Method for Integrating Prior Knowledge Constraints into Neural ODEs

The continuous dynamics of natural systems has been effectively modelled using Neural Ordinary Differential Equations (Neural ODEs). However, for accurate and meaningful predictions, it is crucial that the models follow the underlying rules or laws that govern these systems. In this work, we propose a self-adaptive penalty algorithm for Neural ODEs to enable modelling of constrained natural systems. The proposed self-adaptive penalty function can dynamically adjust the penalty parameters. The explicit introduction of prior knowledge helps to increase the interpretability of Neural ODE -based models. We validate the proposed approach by modelling three natural systems with prior knowledge constraints: population growth, chemical reaction evolution, and damped harmonic oscillator motion. The numerical experiments and a comparison with other penalty Neural ODE approaches and \emph{vanilla} Neural ODE, demonstrate the effectiveness of the proposed self-adaptive penalty algorithm for Neural ODEs in modelling constrained natural systems. Moreover, the self-adaptive penalty approach provides more accurate and robust models with reliable and meaningful predictions

Growth-Driven Percolations: The Dynamics of Community Formation in Neuronal Systems

The quintessential property of neuronal systems is their intensive patterns of selective synaptic connections. The current work describes a physics-based approach to neuronal shape modeling and synthesis and its consideration for the simulation of neuronal development and the formation of neuronal communities. Starting from images of real neurons, geometrical measurements are obtained and used to construct probabilistic models which can be subsequently sampled in order to produce morphologically realistic neuronal cells. Such cells are progressively grown while monitoring their connections along time, which are analysed in terms of percolation concepts. However, unlike traditional percolation, the critical point is verified along the growth stages, not the density of cells, which remains constant throughout the neuronal growth dynamics. It is shown, through simulations, that growing beta cells tend to reach percolation sooner than the alpha counterparts with the same diameter. Also, the percolation becomes more abrupt for higher densities of cells, being markedly sharper for the beta cells.Comment: 8 pages, 10 figure

O tucumã (Astrocaryum vulgare Mart.) principais características e potencialidade agroindustrial.

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Qualidade químico-bromatológica do feno de Cornichão cv. Estanzuela Ganador, cortado em três estádios vegetativos.

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The fracturation influence on the exploitation of ornamental rocks: the case of the Pedras Salgadas granite (Vila Real, North of Portugal)

[Abstract] The exploitation of ornamental granite in Pedras Salgadas region is limited by the regional fault pattern, which is formed by three sets of principal faults. Based upon the joint spacings measurements, the medium was computed for each quarry and for the massif. The medium exploitaion yield of the quarries was also estimated