Figure 4

The permanence of system ( 2.1 ) with \(\pmb{x(0)=1}\) , \(\pmb{y(0)=0.5}\) , \(\pmb{c_{o}(0)=0.5}\) , \(\pmb{c_{e}(0)=0.5}\) , \(\pmb{a=0.4}\) , \(\pmb{b=1}\) , \(\pmb{d=0.1}\) , \(\pmb{\beta=0.05}\) , \(\pmb{\mu=1}\) , \(\pmb{f=0.1}\) , \(\pmb{m=0.1}\) , \(\pmb{g=0.1}\) , \(\pmb{l=0.25}\) , \(\pmb{D=0.1}\) , \(\pmb{\tau=1}\) . (e \(\boldsymbol{'}\) ) Time-series of \(x(t)\); (f \(\boldsymbol{'}\) ) time-series of \(y(t)\); (g \(\boldsymbol{'}\) ) time-series of \(c_{o}(t)\); (h \(\boldsymbol{'}\) ) time-series of \(c_{e}(t)\).