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来源类型 | Other |
Pandemics of Focal Plant Disease: A Model. | |
van den Bosch F; Metz JAJ; Zadoks JC | |
发表日期 | 1997 |
出处 | Technical Note 97-06, Department of Agricultural, Environmental and Systems Technology, Subdepartment of Mathematics, Wageningen Agricultural University, Wageningen, Netherlands (1997) |
出版年 | 1997 |
语种 | 英语 |
摘要 | An analytical model of a pandemic, initiated by a single focus and spreading over a continent, is developed, using foci as the smallest units of disease and fields as the smallest units of host. A few generalizing assumptions lead to a parameter sparse model which may answer general questions on pandemics in a qualitative manner. For pandemic spread of disease during one season a `within-season velocity of pandemic spread', C, is expressed in a set of integral equations. Reduction of inoculum during the off-season is expressed by a `survival ratio' of inoculum, epsilon. The effect of the off-season is a `push-back' of the pandemic front over a distance dh. It will be shown how dh is related to C and epsilon. The mean pandemic spread over successive years is calculated as the `polyetic velocity of pandemic spread', V, which depends on C and the push-back distance. The concept of `pandemic effectiveness' is parameterized. Relations between the two velocities of pandemic spread and several models are studied. Velocities of pandemic spread depend in a limited way on field density represented by the `cropping ratio' zeta. A general conclusion is that eradication and containment of a beginning pandemic becomes more difficult when the pandemic effectiveness of the disease is high, the tail of the spore dispersal probability distribution is long, the the sanitation during the off-season is poor, and the growing or epidemic season is long. |
主题 | Adaptive Dynamics Network (ADN) |
URL | http://pure.iiasa.ac.at/id/eprint/5159/ |
来源智库 | International Institute for Applied Systems Analysis (Austria) |
资源类型 | 智库出版物 |
条目标识符 | http://119.78.100.153/handle/2XGU8XDN/134790 |
推荐引用方式 GB/T 7714 | van den Bosch F,Metz JAJ,Zadoks JC. Pandemics of Focal Plant Disease: A Model.. 1997. |
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