highly significantP = 6.9 × 10 − 4
We obtained a relatively small but significant effect of exposed ( R 2 = 0.005, P = 0.030), a stronger effect of enveloped ( R 2 = 0.032, P < 10 -5 ), and a highly significant interaction between these factors ( R 2 = 0.012, P = 6.9 × 10 − 4 ).