Lack of HFRS in other countries may result from better living conditions, low rat densities, and low SEOV-carrying rates by the rats.
We built a particular model that included the effect of rat density, R, and the statistical interaction between rat abundance and habitat, R×H, but not the main effect of habitat, H (model 2 in Table 1).
F = the average breeding success modelled as a function of rat density, R, and habitat structure, H, as 1/(1+exp[−(α+β(R)+β(R×H))] in which α and β are the linear predictors of F on a logit scale (see Table 1).
First, this study examined only the effect of climate factors and autoregression on HFRS epidemics, without taking into account rat density, socioeconomic circumstances, and countermeasures.
We sampled the entire population by trapping (n = 30), achieving eradication, and found a low rat density (3.2 ha−1) indicative of a sink population.
However, it is almost null when rat density is low as a direct effect of the interaction between rat and habitat structure.
First, controlling the factors that increase adult mortality, e.g. long-line fisheries, has a greater effect on population growth rate than controlling those that limit breeding success, i.e. rat density (Table 1).
Rat densities are similar between Rota and Saipan and higher on both those islands than on Guam (Wiewel et al. 2009), indicating that seed predation by rats is unlikely the reason for the varying seed densities between Saipan and Rota.
Eayrs and colleagues have shown in early studies[ 16, 17] that perinatal hypothyroidism in rats alter the density and size of neurones and fibre density in specific brain regions and the orientation of cortical layers.
After subcutaneous implantation for 1 and 3 months in rats, the blood vessel density and percentage of mature vessels were 3-fold greater in the triple factor-bound scaffolds than in the factor-adsorbed or untreated scaffolds.
