A few cosmological implications of tensor nonlocalities

We consider nonlocal gravity theories that include tensor nonlocalities. We show that in the cosmological context, the tensor nonlocalities, unlike scalar ones, generically give rise to growing modes. An explicit example with quadratic curvature terms is studied in detail. Possible consequences for recent nonlocal cosmological models proposed in the literature are also discussed.Comment: 7 pages. New references include

Heat-Bath and Metropolis Dynamics in Ising-like Models on Directed Regular Random Graphs

Using a single-site mean-field approximation (MFA) and Monte Carlo simulations, we examine Ising-like models on directed regular random graphs. The models are directed-network implementations of the Ising model, Ising model with absorbing states, and majority voter models. When these nonequilibrium models are driven by the heat-bath dynamics, their stationary characteristics, such as magnetization, are correctly reproduced by MFA as confirmed by Monte Carlo simulations. It turns out that MFA reproduces the same result as the generating functional analysis that is expected to provide the exact description of such models. We argue that on directed regular random graphs, the neighbors of a given vertex are typically uncorrelated, and that is why MFA for models with heat-bath dynamics provides their exact description. For models with Metropolis dynamics, certain additional correlations become relevant, and MFA, which neglects these correlations, is less accurate. Models with heat-bath dynamics undergo continuous phase transition, and at the critical point, the power-law time decay of the order parameter exhibits the behavior of the Ising mean-field universality class. Analogous phase transitions for models with Metropolis dynamics are discontinuous.Comment: 14 page

Conservação de castanha por irradiação

Preservação de castanha por irradiação para eliminação dos insectos pós-colheita, como alternativa à fumigação química e ao tratamento por águas quentes, não alterando as principais características do fruto, como a cor, sabor, textura e composição nutricional

Impact of gamma irradiation on nutritional composition and antioxidant activity of Aloysia citriodora Paláu and Melittis melissophyllum L.

Aloysia citriodora Paláu and Melittis melissophyllum L. are examples of plants that have been used for medicinal purposes as dietary supplements or infusions [1,2]. The incorporation of plant extracts/compounds in pharmaceuticals has been increasing. However, due to the high demand of the pharmaceutical industry for the use of raw materials with good microbiological quality, decontamination techniques should be applied. Irradiation arises as an alternative [3]. The aim of this work was to evaluate the effects of gamma irradiation (0 kGy – control, 1 kGy and 10 kGy) on nutritional value and antioxidant activity of A. triphylla and M. melissophyllum. The nutritional value was determined following official analysis methodologies; free sugars were analyzed by high performance liquid chromatography coupled to a refraction index detector (RI-HPLC), fatty acids by gas chromatography coupled with a flame ionization detector (GC-FID), and tocopherols by HPLC-fluorescence. The antioxidant properties of the infusions were evaluated through free radicals scavenging activity, reducing power and inhibiting of lipid peroxidation. In general, gamma irradiation protected fructose, trehalose, and the major fatty acids found in A. citriodora. Furthermore, the dose of 10 kGy protected oxalic, malic, and quinic acids, as also protein and ash levels and revealed the highest antioxidant activity for the majority of the assays. The dose of 1 kGy protected all isoforms of tocopherols detected in the plant. Regarding M. melissophyllum, it was concluded that the control sample (non-irradiated) showed the highest antioxidant activity, as well as the highest levels of -tocopherol. However, in general, it was observed that a dose of 10 kGy maintains the nutritional properties of the plant, such as protein and ash levels. Thus, we can conclude that irradiation is a decontaminating technique that does not interfere drastically with the chemical properties of the studied plants.Proder (Project nº 53514, AROMAP) and to Fundação para a Ciência e a Tecnologia (FCT, Portugal) for financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2011). The authors are also grateful to “MaisErvas - Aromáticas e Medicinais” for samples providing

Flores comestíveis: múltiplas utilizações do mais belo da natureza

As flores comestíveis têm vindo a tornar-se cada vez mais populares, o que se torna claramente evidente pelo aumento de livros de receitas, artigos de revistas e sites sobre o tema, para além do crescimento da investigação científica relacionada com o seu potencial nutricional. O foco principal é a alta gastronomia, atraindo a atenção de gourmets e chefs.Projecto bilateral FCT – CNPq, Portugal/Brazil 2014-201

Efeito da radiação gama nos níveis de tocoferóis em Lactarius deliciosus

Os efeitos da radiação gama no teor de tocoferóis em Lactarius deliciosus L. Gray foi avaliado em amostras submetidas a diferentes períodos de armazenamento a 4 ºC. As doses aplicadas foram 0,5 e 1 kGy a um débito de dose de 2,3 kGy/h, usando uma câmara de radiação gama com fonte de 60Co. Após tratamento, as amostras foram armazenadas sob refrigeração (4 a 5 ºC) e analisadas aos 0, 4 e 8 dias de armazenamento. A composição em tocoferóis foi determinada por HPLC-fluorescência. As amostras não sujeitas a radiação e analisadas de imediato foram os únicos casos em que se detetou β-tocoferol (93±11 μg/100 g massa seca) e γ-tocoferol (68±6 μg/100 g massa seca); sendo que as restantes isoformas diminuíram nas amostras irradiadas e armazenadas, presumivelmente devido a processos oxidativos. Os dados obtidos mostram que, até 1 kGy, a irradiação gama pode fornecer uma alternativa conveniente para garantir a qualidade e prolongar a vida útil de cogumelos.FCT e COMPETE/QREN/UE- projetos estratégicos PEst-OE/AGR/UI0690/2011 do CIMO e PEst-C/EQB/LA0006/2011 do REQUIMTE; bolsa SFRH/BD/76019/2011 concedida a A. Fernande

Analytical methods applied to assess the effects of gamma irradiation on color, chemical composition and antioxidant activity of Ginkgo biloba L

The extracts from the leaves of Ginkgo biloba are widely used in medicines and food supplements in order to overcome different health problems. To provide decontamination, irradiation is a safe and effective technique, particularly suitable to be integrated in quality control of the postharvest samples. In this study, different analytical methods were applied to assess the effects of gamma irradiation (1 and 10 kGy) in G. biloba color, chemical composition and antioxidant properties. Irradiation preserved macronutrients, fatty acids, γ- and δ-tocopherols, fructose, trehalose, quinic and shikimic acids. In particular, 1 kGy protected α-tocopherol, oxalic and malic acids contents, while 10 kGy decreased α-tocopherol, glucose, sucrose, oxalic and malic acids level. Nevertheless, this dose was the most effective for antioxidant activity. Overall, 1 kGy would be the recommended dose to maintain nutritional profile of G. biloba, protect specific molecules and also increase antioxidant activity of infusion and methanolic extracts prepared from its leaves.The authors are grateful to Fundação para a Ciência e a Tecnologia (FCT, Portugal) for financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2011). The authors are also grateful to Clarinda Paixão, from Américo Duarte Paixão Lda, for samples providing