Browsing by Author "Li, F."
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- ItemContinuously stable strategy of pathogen evolution in a classic epidemiological SIR model(Oriprobe Information Services, Inc, 2018) Han, X.-Z.; Hui, C.; Li, F.; Lin, M.-X.Using the framework of adaptive dynamics, here a classic susceptible-infected-recovery (SIR) host- pathogen model was considered to explore the evolutionary dynamics of pathogen virulence. Both transmission rate and recovery rate were assumed to be constrained by trade-offs with the pathogenic virulence, and the trade-offs crucially determined the behavior of the evolutionary dynamics. No additional increase in mortality due to infection was assumed and the invasion fitness and evolutionary trajectories of pathogen virulence were explored using pairwise invadability plots. The results showed that initial strains of viruses with different levels of virulence converged to one continuously stable singular point, prohibiting any other complex evolutionary outcomes to occur on the strain diversity. The insufficient nonlinearity in the population dynamics and the lack of additional increase of mortality due to infection could have led to the lack of evolutionary diversity, which could, nonetheless, serve as the base for developing potential mechanisms for reducing the diversity of virus strains in public health management.
- ItemThe effect of temperature on the developmental rates of seedling emergence and leaf-unfolding in two dwarf bamboo species.(Springer, 2018) Lin, S.; Shao, L.; Hui, C.; Sandhu, H.S.; Fan, T.; Zhang, L.; Li, F.; Ding, Y.; Shi, P.Key message: The mean and variance of developmental rates of bamboos at different temperatures follow a power law. The rate isomorphy hypothesis, demonstrated in insects and mites, does not hold in bamboos. The developmental time of plants and poikilotherms can be significantly affected by temperature. Developmental rate (i.e. the reciprocal of developmental time) of arthropods and germination rate of some plant seeds have been demonstrated to follow a linear function with temperature. The rate isomorphy hypothesis in entomology suggests a lower developmental threshold below which development of all life stages terminates. If this hypothesis also holds for plants, the estimated lower threshold for one development stage could be used for predicting thresholds of other stages. Here, we tested this hypothesis to compare the developmental time of seedling emergence and the time from seedling emergence to the unfolding of the third leaf in two bamboo species. We used five constant thermal environments from 18.5 to 28.5 °C with an increment of 2.5 °C. Both species showed a linear relationship between temperature and developmental rate, with the mean and variance of developmental rates following a power law. Using the bootstrap percentile method, we showed that the isomorphy hypothesis does not hold for both species. The effect of temperature on the survival rate at the time of seedling emergence differed significantly between the two species.