Behavioral observation, economic, and genealogical data collected in a rural Trinidadian village indicate: (1) males courting the same females have higher rates of agonistic interactions (e.g., arguing, fighting) with each other than they do with other mates; (2) females courting the same males do not have higher rates of agonistic interactions with each other than they do with other females; (...

When social animals engage in inter-group contests, the outcome is determined by group sizes and individual masses, which together determine group resource-holding potential ('group RHP'). Individuals that perceive themselves as being in a group with high RHP may receive a motivational increase and increase their aggression levels. Alternatively, individuals in lower RHP groups may increase the...

In male golden hamsters, exposure to social stress during puberty alters aggressive behavior. Interestingly, agonistic behavior undergoes two major transitions during puberty: a decline in attack frequency and a shift from play fighting to adult-like aggression. Based on previous observations, we developed an approach for characterizing offensive responses as play fighting or adult-like. The pr...

Background: The organochlorine DDT has estrogenic activity but the mechanism underlying the estrogenic activity of this pesticide remains unclear. In the present investigation here, we studied the transcriptional effects of a synthetic organochlorine pesticide o,p’-DDT [1.1.1.-trichloro-2-(o-chlorophenyl)-2-p-chloriphenyl ethane] and its metabolite p,p'-DDE (2-2-bis(4/chlorophenyl)-1-1-di...

California sea lions aggregate in high density colonies during the breeding season. Competition for space and mates results in agonistic interactions that may have long-term population consequences. We explored how demographic, behavioral, and environmental variables influence the rate of agonistic interactions in male and female California sea lions at three breeding colonies with varying popu...

Reason can be defined in many ways, and more than one definition would fertile ground for investigation the Ajax. Perhaps most tempting way to understand Reason, especially given theme of insanity play, is as sanity; however, might also understood an interpersonal phenomenon, ability individuals ‘reason’ together, negotiating arguing reach agreement. It this agonistic (agonistic that it what ch...

We examined agonistic behaviour in seven species of hatchling and juvenile crocodilians held in small groups (N = 4) under similar laboratory conditions. Agonistic interactions occurred in all seven species, typically involved two individuals, were short in duration (5-15 seconds), and occurred between 1600-2200 h in open water. The nature and extent of agonistic interactions, the behaviours di...

Interleukin 7 (IL-7) is an essential cytokine that acts as a potent growth factor of T-cells and supports the B-cell precursors. IL-7 binds to heterodimeric receptor consisting alpha (IL-7Rα) common gamma chain (γc) which shared with IL-2, IL-4, IL-9, IL-15 IL-21. The discovery small-molecule agonists cytokines would be great pharmaceutical interest increasing scientific rationale. In this stud...