Prediction of invasion from the early stage of an epidemic

Predictability of undesired events is a question of great interest in many scientific disciplines including seismology, economy and epidemiology. Here, we focus on the predictability of invasion of a broad class of epidemics caused by diseases that lead to permanent immunity of infected hosts after recovery or death. We approach the problem from the perspective of the science of complexity by proposing and testing several strategies for the estimation of important characteristics of epidemics, such as the probability of invasion. Our results suggest that parsimonious approximate methodologies may lead to the most reliable and robust predictions. The proposed methodologies are first applied to analysis of experimentally observed epidemics: invasion of the fungal plant pathogen Rhizoctonia solani in replicated host microcosms. We then consider numerical experiments of the susceptible–infected–removed model to investigate the performance of the proposed methods in further detail. The suggested framework can be used as a valuable tool for quick assessment of epidemic threat at the stage when epidemics only start developing. Moreover, our work amplifies the significance of the small-scale and finite-time microcosm realizations of epidemics revealing their predictive power.     

Fault Recovery in Time-Synchronized Mission Critical ZigBee-Based Wireless Sensor Networks

Reliability and precise timestamping of events that occur are two of the most important requirements for mission critical wireless sensor networks. Accurate timestamping is obtained by synchronizing the nodes to each other while reliability can be obtained by eliminating single points of failure (SPF). In this paper, we address the SPF problem of a ZigBee-based wireless sensor network by means of using multiple coordinators with different personal area network identifiers (PAN IDs). We propose a solution where members of a network switch from one coordinator to another in case of failure by changing their respective PAN ID. We verify experimentally that our solution provides gains in terms of recovery speed and, therefore, synchronization accuracy with respect to a solution proposed in the literature.     

Scalable production of calcite nanocrystals by atomization process: Synthesis,characterization and biological interactions study

Nowadays, there is strong interest in the development of smart inorganic nanostructured materials as tools for targeted delivery in cancer cells. We proposed a novel synthetic procedure of calcium carbonate nanocrystals (NCs) and their use as drug delivery systems, studying the physical chemical properties and the in vitro interaction with two model cancer cells.Pure and thermodynamically stable CaCO₃ NCs in calcite phase were synthesized by a readily and feasible method, easily scalable, that allows the control of NCs shape and size without any surfactant use. CaCO₃ NCs were extensively investigated by Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), X-ray Diffraction (XRD), Raman spectroscopy and Brunauer–Emmett–Teller analysis (BET). To deeper investigate their possible use as nanovectors for drug cancer therapies, CaCO₃ NCs biocompatibility (by MTT assay), cell interaction and internalization were studied in in vitro experiments on HeLa and MCF7 cell lines. Confocal and transmission electron microscopies were used to monitor and evaluate NCs-cell interaction and cellular uptake.Data here reported demonstrated that synthesized NCs readily penetrate HeLa and MCF7 cells. NCs preferentially localize inside the cytoplasm, but were also found into mitochondria, nucleus and lysosomes. This study suggests that synthesized CaCO₃ NCs are good candidates as effective intracellular therapeutic delivery system.     

Investigation and modelling of natural convection and conduction heat exchange: study on food systems with modified starch by means of computational fluid dynamics

This study is focused on the effects of starch gelatinisation on heat exchange in food systems containing four modified starch concentrations (0, 2, 6 and 10%). Viscosity profiles of samples were experimentally measured: the effect of gelatinisation was evident, particularly at 6% and 10%, where the viscosity increased from 0.010 to 70 Pa s and to 1507 Pa s, respectively. The heat exchange rate showed a decrease with the increasing of starch concentration, and the effects were observed until 6%. Four Computational Fluid Dynamics (CFD) models were also developed, experimentally validated (RMSE < 1.5 °C) and used to study the heat exchange. Velocity profiles showed that the convective flows slowed down from 2.5 to 0 mms^?1 after the gelatinisation. Finally, the effects on the slowest heating/cooling zone (SHZ/SCZ) location in the CFD models were studied: at 0% and 2%, the SHZ settled 15 and 80 mm from the bottom of jars in heating and cooling phase, respectively. At 6% and 10%, before the starch gelatinisation phase, the SHZ was located in a similar position of the 0% and 2% while when the gelatinisation occurred the SHZ slightly moved towards the geometric centre (50 mm) as for an only‐conductive product.     

Fatigue and healing properties of bituminous mastics reinforced with nano-sized additives

The research work described in the paper focused on fatigue and healing properties of bituminous mastics reinforced with nano-sized additives.Commercially available multiwall carbon nanotubes (CNTs) and montmorillonite nanoclay (NC) were combined with a single base bitumen and a standard mineral filler to produce bituminous mastics. These blends were prepared in the laboratory by making use of a technique consisting in simple shear mixing followed by sonication.Fatigue behaviour of mastics under repeated loading was investigated by means of time sweeps performed in the strain-controlled mode at various amplitudes. Healing potential was assessed by adopting a testing protocol specifically conceived to discriminate between recovery of damage induced by fatigue loading and other artefact phenomena which may affect material response. All rheological measurements were carried out with a dynamic shear rheometer in the parallel plates geometry.Outcomes of the experimental investigation were found to be highly dependent on the nature of additive type, as a result of the key role played by interaction mechanisms that nano-particles can establish within the bituminous mastic.