ckage{upgreek} 				\setlength{\oddsidemargin}{-69pt} 				\begin{document}$$ \left\{\begin{array}{c}\frac{d{s}_P}{dt}={n}_P-{m}_P{s}_P-{b}_P{s}_P\left({i}_P+\upkappa {a}_P\right)-{b}_W{s}_Pw\\ {}\fra