the effects of some histaminergic agents were evaluated on stress- induced immunosuppression in immunized nale rats. in rat immunized with sheep red blood cells ( srbcs). restraint stress (rs) prevented the booster-induced rise in anti-srbc antibody titre and cell immunity response. intracerebroventicular (i.c>v) injection of histamine (150 µg/rat) induced a similar effect with rs. pretreatment...

Collective action is more likely to occur and to be effective when it is consistent with the self-interest of the affected individuals. The Maine lobster fishery is an instructive example of biological and technological circumstances combining with individual self-interest to create conditions favorable to collective action. The model describes the way social structure emerges from the adaptive...