Microinjections of the dopamine agonist apomorphine into the nucleus basalis prosencephali of pigeons elicit stereotyped pecking behaviour. Injections of 6-hydroxydopamine, a toxic dopamine antagonist, into the same nucleus impair stereotyped pecking induced by systemic apomorphine administration, but do not interfere with pecking in the normal feeding context.

The production and coordination of rhythmic activities in birds is seldom investigated. Here we describe the pecking and breathing rhythms of pigeons under different conditions. When feeding from a heap of small grains, hungry pigeons pecked at regular intervals of about 0.3 s. The pecking rhythm was slightly slo,":,er in the afternoon. The pecking rhythm induced by the dopaminergic drug apomor...

Asymmetric information models predict a “pecking order” which reflects a combination of owner-manager preferences and external capital supply constraints whenever insiders know more about the true value of the firm’s prospects than outsiders. The pecking order results in retained earnings being the most preferred source of finance, then debt and finally the issue of new shares to outsiders. Usi...

We quantify the empirical relevance of the pecking order hypothesis using a novel empirical model and testing strategy that addresses statistical power concerns with previous tests. While the classificatory ability of the pecking order varies significantly depending on whether one interprets the hypothesis in a strict or liberal (e.g., “modified” pecking order) manner, the pecking order is neve...

Free radicals are species with one or more unpaired electrons. The unpaired electron results in a species that is often highly reactive. Free radicals have a wide range of reactions; two broad classes of reactions are electron transfer and addition reactions resulting in covalent bond formation. Free radicals can be classified as reducing (donating an electron to an acceptor) or oxidizing (acce...

Background; Feather waste is generated in large amounts as a by-product of commercial poultry processing. The main component of feather is keratin. The main purpose of this study was to identify Bacillus spp. (the keratinolytic bacteria) that are able to degrade the feather for producing keratin. Methods; Bacillus spp. Were isolated from the waste of poultries located in Miyaneh city. The bact...