Winning Fights Induces Hyperaggression via the Action of the Biogenic Amine Octopamine in Crickets

Winning an agonistic interaction against a conspecific is known to heighten aggressiveness, but the underlying events and mechanism are poorly understood. We quantified the effect of experiencing successive wins on aggression in adult male crickets (Gryllus bimaculatus) by staging knockout tournaments and investigated its dependence on biogenic amines by treatment with amine receptor antagonists. For an inter-fight interval of 5 min, fights between winners escalated to higher levels of aggression and lasted significantly longer than the preceding round. This winner effect is transient, and no longer evident for an inter-fight interval of 20 min, indicating that it does not result from selecting individuals that were hyper-aggressive from the outset. A winner effect was also evident in crickets that experienced wins without physical exertion, or that engaged in fights that were interrupted before a win was experienced. Finally, the winner effect was abolished by prior treatment with epinastine, a highly selective octopamine receptor blocker, but not by propranolol, a ß-adrenergic receptor antagonist, nor by yohimbine, an insect tyramine receptor blocker nor by fluphenazine an insect dopamine-receptor blocker. Taken together our study in the cricket indicates that the physical exertion of fighting, together with some rewarding aspect of the actual winning experience, leads to a transient increase in aggressive motivation via activation of the octopaminergic system, the invertebrate equivalent to the adrenergic system of vertebrates

Release and Transformation of Sodium in Kitchen Waste during Torrefaction

The release and transformation of typical chemical forms of sodium (i.e., H2O-soluble salts and carboxylates) in kitchen waste during torrefaction at 200-300 °C was investigated in this study. It was found that sodium release is negligible (<2%) at 200 °C after torrefaction for 15 min, but the release increases to ~10% when the temperature is increased to 300 °C. Because of the high concentration of water-soluble sodium in raw noodles, the release of sodium during torrefaction is mainly in the form of NaHCO3 or Na2CO3, as NaCl is relatively stable at torrefaction temperatures. The transformation of Na from a water-soluble form to a CH3COONH4-soluble form during torrefaction was found to be an important factor in the release of sodium from raw noodles, since sodium release occurs much more readily from a Na-exchanged sample during torrefaction.CH3COONH4-soluble sodium is also found to transform back into a water-soluble form during torrefaction. For example, ~18% of the sodium in a Na-exchanged sample transforms to a water-soluble form (i.e., Na2CO3) at 300 °C, indicating the existence of an interconversion mechanism between the water-soluble and CH3COONH4-soluble forms. A small amount of water-soluble orCH3COONH4-soluble sodium could also transform to acid-soluble and stable forms during torrefaction at high temperatures (i.e., 300 °C)