Disease extinction in the presence of non-Gaussian noise

Extinctions of coupled populations, and rare-event dynamics under non-Gaussian noise

The survival of natural populations may be greatly affected by environmental conditions that vary in space and time. We look at a population residing in two locations (patches) coupled by migration, in which the local conditions fluctuate in time. We report on two findings. First, we find that unlike rare events in many other systems, here the histories leading to a rare extinction event are not dominated by a single path. We develop the appropriate framework, which turns out to be a hybrid of the standard saddle-point method, and the Donsker-Varadhan formalism which treats rare events of atyp…

Noise can lead to exponential epidemic spreading despite $R_0$ below one

Branching processes are widely used to model evolutionary and population dynamics as well as the spread of infectious diseases. To characterize the dynamics of their growth or spread, the basic reproduction number $R_0$ has received considerable attention. In the context of infectious diseases, it is usually defined as the expected number of secondary cases produced by an infectious case in a completely susceptible population. Typically $R_0>1$ indicates that an outbreak is expected to continue and to grow exponentially, while $R_0<1$ usually indicates that an outbreak is expected to terminate…

Correlated noise induced control of prey extinction

We study the steady state properties of a phenomenological two-state predator model in presence of correlated Gaussian white noise. Based on the corresponding Fokker-Planck equation for probability distribution function the steady state solution of the probability distribution function and its extrema have been investigated. We show for a typical value of noise correlation there is a giant loss of bistability which in turn prevents the prey population from going into extinction.

Spatial effects in parasite induced marine diseases of immobile hosts

Emerging marine infectious diseases pose a substantial threat to marine ecosystems and the conservation of their biodiversity. Compartmental models of epidemic transmission in marine sessile organisms, available only recently, are based on non-spatial descriptions in which space is homogenised and parasite mobility is not explicitly accounted for. However, in realistic scenarios epidemic transmission is conditioned by the spatial distribution of hosts and the parasites mobility patterns, calling for a explicit description of space. In this work we develop a spatially-explicit individual-based …

使用高斯过程对计算肺血流动力学模型进行贝叶斯参数推断与不确定性量化

Bayesian Parameter Inference and Uncertainty Quantification for a Computational Pulmonary Hemodynamics Model Using Gaussian Processes

本研究利用高斯过程仿真器加速一维肺血流动力学模型的校准，在临床可行时间内推断CTEPH微血管参数及不确定性，发现参数变化与疾病严重程度高度相关，为微血管功能障碍评估提供了快速且具备不确定性感知的框架。