How disease risk awareness modulates transmission: coupling infectious disease models with behavioural dynamics

Epidemiological models often assume that individuals do not change their behaviour or that those aspects are implicitly incorporated in parameters in the models. Typically, these assumptions are included in the contact rate between infectious and susceptible individuals. However, adaptive behaviours are expected to emerge and play an important role in the transmission dynamics across populations. Here, we propose a theoretical framework to couple transmission dynamics with behavioural dynamics due to infection awareness. We modelled the dynamics of social behaviour using a game theory framework, which is then coupled with an epidemiological model that captures the disease dynamics by assuming that individuals are aware of the actual epidemiological state to reduce their contacts. Results from the mechanistic model show that as individuals increase their awareness, the steady-state value of the final fraction of infected individuals in a susceptible-infected-susceptible (SIS) model decreases. We also incorporate theoretical contact networks, having the awareness parameter dependent on global or local contacts. Results show that even when individuals increase their awareness of the disease, the spatial structure itself defines the steady state.

Protein Fractionation of Green Leaves as an Underutilized Food Source—Protein Yield and the Effect of Process Parameters

Green biomass has potential as a sustainable protein source for human consumption, due to its abundance and favorable properties of its main protein, RuBisCO. Here, protein fractionation outcomes of green leafy biomass from nine crops were evaluated using a standard protocol with three major steps: juicing, thermal precipitation, and acid precipitation. Successful protein fractionation, with a freeze-dried, resolubilized white protein isolate containing RuBisCO as the final fraction, was achieved for seven of the crops, although the amount and quality of the resulting fractions differed considerably between crops. Biomass structure was negatively correlated with successful fractionation of proteins from biomass to green juice. The proteins in carrot and cabbage leaves were strongly associated with particles in the green juice, resulting in unsuccessful fractionation. Differences in thermal stability were correlated with relatedness of the biomass types, e.g., Beta vulgaris varieties showed similar performance in thermal precipitation. The optimal pH values identified for acid precipitation of soluble leaf proteins were lower than the theoretical value for RuBisCO for all biomass types, but with clear differences between biomass types. These findings reveal the challenges in using one standard fractionation protocol for production of food proteins from all types of green biomass and indicate that a general fractionation procedure where parameters are easily adjusted based on biomass type should instead be developed.

Adaptive staffing can mitigate essential worker disease and absenteeism in an emerging epidemic

Essential worker absenteeism has been a pressing problem in the COVID-19 pandemic. Nearly 20% of US hospitals experienced staff shortages, exhausting replacement pools and at times requiring COVID-positive healthcare workers to remain at work. To our knowledge there are no data-informed models examining how different staffing strategies affect epidemic dynamics on a network in the context of rising worker absenteeism. Here we develop a susceptible–infected–quarantined-recovered adaptive network model using pair approximations to gauge the effects of worker replacement versus redistribution of work among remaining healthy workers in the early epidemic phase. Parameterized with hospital data, the model exhibits a time-varying trade-off: Worker replacement minimizes peak prevalence in the early phase, while redistribution minimizes final outbreak size. Any “ideal” strategy requires balancing the need to maintain a baseline number of workers against the desire to decrease total number infected. We show that one adaptive strategy—switching from replacement to redistribution at epidemic peak—decreases disease burden by 9.7% and nearly doubles the final fraction of healthy workers compared to pure replacement.

How punishment and memory mechanism affect cooperative emergence in prisoner’s dilemma game

To remember or forget our acquaintances’ strategies can influence our decision-making significantly. In this paper, we explore the evolutionary prisoner’s dilemma (PD) game model with punishment and memory mechanism in the time-varying network. Our results show that a larger temptation gain [Formula: see text] or a larger the number of connected edges of activated individuals [Formula: see text] would result in the decrease of the final fraction of cooperators. However, with the increase of the maximum penalty cost, the maximum punishment intensity or the value of individual’s “memory factor”, players are more inclined to choose cooperative strategy. In addition, an effective way to promote the cooperation is to improve the social subsidy. Remarkably, only when the social subsidy is greater than the temptation gain, the density of cooperators could increase significantly. Interestingly, there is a linear relationship between the threshold of social subsidy and the temptation gain. The final results show that ones’ activity rates have no significant correlation with their strategies.

Effects of seeds on cooperate epidemic spreading on complex networks

We study the impact of seeds on cooperate epidemic spreading on complex networks. A cooperative spreading model is proposed, in which two diseases are spreading simultaneously. Once the nodes are infected by one disease, they will have a larger probability of being infected by the other. Besides, we adopt five different selection strategies to choose the seeds, and the set size of seeds is fixed at five nodes. Through extensive Monte Carlo simulations, we find that the final fraction of nodes that have been infected by one or both diseases display continuous phase transition on both synthetic networks and real-world networks, and the selection strategy does not alter the transition type. Besides, we find that the eigenvector centrality promotes the cooperative spreading on the artificial network, and the degree centrality promotes the spreading of the two cooperative diseases on the real-world networks. The results of this study are of great significance for the development of the targeted strategies of disease control.

A Metric Fractionator for Estimation of Total Cell Number in Paraffin-Embedded Flat or Hollow Organs

The physical fractionator is a convenient and practical solution for estimation of total cell number in a regulatory toxicology setting because it is insensitive to shrinkage allowing for paraffin processing/embedding and does not require measurement of the reference or organ volume. The principle involves sampling a known fraction of an organ in one or more steps and counting the total number of cells present in the final sample, physical disector section pairs. The total cell number in the organ is estimated by multiplying the cell count in the final fraction by the inverse of the sampling fraction(s). The key feature of the design is that tissue shrinkage due to paraffin processing occurs before the organ is uniformly sampled. Another requirement is that thermal expansion or contraction is avoided during the preparation of disector sections from the individual embedded subsamples, which ensures that the disector sections represent a known constant fraction. This vertical physical fractionator with subsampling is a simple and fast estimator to obtain precise and robust estimates of total cell number in large flat or hollow organs that do not prolong routine necropsy procedures. It is compatible with paraffin processing, avoids exhaustive sectioning, and allows for the collection of routine histopathology sections.

Physical properties of terrestrial planets and water delivery in the habitable zone using N-body simulations with fragmentation

Aims. The goal of this research is to study how the fragmentation of planetary embryos can affect the physical and dynamical properties of terrestrial planets around solar-type stars. Our study focuses on the formation and evolution of planets and water delivery in the habitable zone (HZ). We distinguish class A and class B HZ planets, which have an accretion seed initially located inside and beyond the snow line, respectively. Methods. We developed an N-body integrator that incorporates fragmentation and hit-and-run collisions, which is called D3 N-body code. From this, we performed 46 numerical simulations of planetary accretion in systems that host two gaseous giants similar to Jupiter and Saturn. We compared two sets of 23 N-body simulations, one of which includes a realistic collisional treatment and the other one models all impacts as perfect mergers. Results. The final masses of the HZ planets formed in runs with fragmentation are about 15–20% lower than those obtained without fragmentation. As for the class A HZ planets, those formed in simulations without fragmentation experience very significant increases in mass with respect to their initial values, while the growth of those produced in runs with fragmentation is less relevant. We remark that the fragments play a secondary role in the masses of the class A HZ planets, providing less than 30% of their final values. In runs without fragmentation, the final fraction of water of the class A HZ planets keeps the initial value since they do not accrete water-rich embryos. In runs with fragmentation, the final fraction of water of such planets strongly depends on the model used to distribute the water after each collision. The class B HZ planets do not show significant differences concerning their final water contents in runs with and without fragmentation. From this, we find that the collisional fragmentation is not a barrier to the survival of water worlds in the HZ.

Separation of immunoglobulins from colostrum using methods based on salting-out techniques

This study aimed to obtain a purified IgG fraction from bovine colostrum using salting-out precipitation methods as base techniques. As the first step after skimming of colostrum, isoelectric precipitation or rennet coagulation were used for casein removal. IgG concentrations in raw material and final products were determined using the ELISA method. SDS-PAGE electrophoresis was used for purity determination of the final fraction of IgG. According to the obtained results, the combination of precipitation, gel filtration, and cross-flow filtration techniques enables to separate the IgG fraction with purity up to 90% and yield up to 91%. Acid whey has a higher yield in comparison with sweet whey and both ammonium sulphate and sodium sulphate have similar effectivity for precipitation of IgG. The final concentrate of IgG can be used as a standalone product or as an additive to other food supplements.

Anti-Platelet Fraction Isolated from Galega Officinalis

Summary A fraction from crude extract of Galega officinalis has been purified by column chromatography on Sephadex G-25, Sepharose 4B, DEAE-Cellulose and Sephadex G-100. The final purification factor of the fraction is 120. The peak in elution profile after Sephadex G-150 shows a molecular weight of 100-140 kDa. The isolated fraction appears to have 74% polysaccharides and 23% of proteins. No loss of activity of the final fraction is observed after storage for several months at 4°C and in lyophilized condition. The fraction compounds inhibit platelet aggregation induced by ADP, collagen and thrombin.

Quantification of Phase Transformation Kinetics under Thermomechanical Conditions Using Dilatometry Data

Using dilatometric technique, it is the purpose of present research to quantify the kinetics of austenite decomposition during cooling after isothermal hot compression. To reach this aim, based on lattice parameters and thermal expansion coefficients of different phases, a new model was proposed. In this model, the contributions of both isotropic and non-isotropic dilatations were considered. The model was applied to 22MnB5 steel to predict formation of bainite and martensite. Furthermore, the model was developed in order to determine the final fraction of deformation induced ferrite (DIF).