Scaling effect in COVID-19 spreading: The role of heterogeneity in a hybrid ODE-network model with restrictions on the inter-cities flow.

The new Covid-19 pandemic has left traces of suffering and devastation to individuals of almost all countries worldwide and severe impact on the global economy. Understanding the clinical characteristics, interactions with the environment, and the variables that favor or hinder its dissemination help the public authorities in the fight and prevention, leading for a rapid response in society. Using models to estimate contamination scenarios in real time plays an important role. Population compartments models based on ordinary differential equations (ODE) for a given region assume two homogeneous premises, the contact mechanisms and diffusion rates, disregarding heterogeneous factors as different contact rates for each municipality and the flow of contaminated people among them. This work considers a hybrid model for covid-19, based on local SIR models and the population flow network among municipalities, responsible for a complex lag dynamic in their contagion curves. Based on actual infection data, local contact rates ( ß ) are evaluated. The epidemic evolution at each municipality depends on the local SIR parameters and on the inter-municipality transport flow. When heterogeneity of ß values and flow network are included, forecasts differ from those of the homogeneous ODE model. This effect is more relevant when more municipalities are considered, hinting that the latter overestimates new cases. In addition, mitigation scenarios are assessed to evaluate the effect of earlier interventions reducing the inter-municipality flux. Restricting the flow between municipalities in the initial stage of the epidemic is fundamental for flattening the contamination curve, highlighting advantages of a contamination lag between the capital curve and those of other municipalities in the territories.

Organic walled microfossils in wet peperites from the early Cretaceous Paraná-Etendeka volcanism of Brazil.

Large igneous provinces (LIPs) are major magmatic events that have a significant impact on the global environment and the biosphere, for example as triggers of mass extinctions. LIPs provide an excellent sedimentological and geochemical record of short but intense periods of geological activity in the past, but their contribution towards understanding ancient life is much more restricted due to the destructive nature of their igneous origin. Here, we provide the first paleontological evidence for organic walled microfossils extracted from wet peperites from the Early Cretaceous Paraná-Etendeka intertrappean deposits of the Paraná basin in Brazil. Wet peperites are a volcaniclastic rock formed by the interaction of lava and subaqueous sediments.The Paraná-Etendeka was formed during the Valanginian (ca. 132 Ma) as a continental flood basalt in present day South America and Namibia, and released enormous amounts of carbon dioxide, sulfur dioxide, methane and hydrogen fluoride into the atmosphere. The organic walled microfossils recovered from the Paraná-Etendeka peperites include pollen grains, spores, acritarchs, and other remains of unidentifiable organic matter. In addition to the peperites, organic walled microfossils were also found in heterolithic sandstones and interpillow sandstones. Our findings represent the first insight into the biodiversity of the Paraná Basin during the Early Cretaceous during a period of intense magmatism, and the microfossil assemblages corroborate a regional paleoclimatic transition from arid to more humid conditions that were likely induced by the volcanic activity. We corroborate the potential of wet peperite rocks as a valuable source of paleobiological data and emphasize the importance of sampling volcaniclastic units that have been traditionally considered with lower fossiliferous potential due to their igneous origin.

Copaiba oil and vegetal tannin as functionalizing agents for açai nanofibril films: valorization of forest wastes from Amazonia.

The applicability of cellulose nanofibrils (CNFs) has received attention due to their attractive properties. This study proposes the functionalization of açai CNFs with copaiba oil and vegetal tannins to produce films with potential for packaging. Bio-based films were evaluated by vapor permeability, colorimetry, and mechanical strength. CNFs were produced by mechanical fibrillation, from suspensions of bleached açai fibers and commercial eucalipytus pulp. Moreover, copaiba oil and vegetal tannin were added to the CNFs to produce films/nanopapers by casting from both suspensions with concentrations of 1% (based on CNF dry mass). The bulk densities of the eucalyptus CNF films were higher (1.126-1.171 g cm-3) compared to the açai CNF ones. Films from eucalyptus and açai pulps containing copaiba oil and tannins presented higher Tonset and Tmax, respectively (312 and 370 °C). Films with açaí CNFs functionalized with copaiba oil and tannin showed the lowest permeability value (370 g day-1 m-2). Films produced with eucalyptus pulp, and eucalyptus pulp functionalized with copaiba oil highlighted by superior mechanical strength, achieving 133.8 and 121.4 MPa, respectively. The evaluation of colorimetry showed a greater tendency to yellowing for açai films, especially those functionalized with vegetal tannins. Besides the low cost, functionalized vegetal-based nanomaterials could have attractive properties, with potential for application as some kind of packaging, for transporting basic products, such as breads, flours, or products with low moisture content, enabling efficient utilization of forest wastes.