J Exp Psychol Anim Behav Process
April 1999
The durations of animals' brief vocalizations provide conspecifics with important recognition cues. In the present experiments, zebra finches and humans (trained musicians) were rewarded for responding after S+ (standard) auditory signals from 56 to 663 ms and not for responding after shorter or longer S- (comparison) durations from 10 to 3684 ms. With either a single standard (Experiment 1) or multiple standards (Experiment 2), both zebra finches and humans timed brief signals to about the same level of accuracy.
View Article and Find Full Text PDFPhysiol Behav
September 1996
This report describes simple modifications to a stereotaxic instrument that allow for the administration of an inhalant anaesthetic and provide improved access to avian dorsal forebrain structures along with a more natural orientation for small birds during neurosurgery.
View Article and Find Full Text PDFJ Gen Microbiol
December 1990
The effects of changing the composition of the growth medium, the dilution rate and the source of the bacterial host on maintenance of the plasmid pAT153 in Escherichia coli HB101 have been studied. In a medium supplemented with Casamino acids, the plasmid was maintained longer during phosphate-limited growth at a dilution rate of 0.3 h-1 than at 0.
View Article and Find Full Text PDFTwo derivatives of plasmid pAT153 which arose spontaneously in phosphate-limited continuous cultures of Escherichia coli HB101[pAT153] have been characterised. The smaller plasmid, pLAB-446, resulted from a deletion of 446 base pairs of DNA covering the translation start and codon sequence of the tetracycline resistance gene. The other plasmid, pLAB135, differed from pAT153 only by an A:T to G:C transition in the transcribed but untranslated leader region of the tet gene which decreased tet transcription by 84%, possibly due to the formation of a more stable stem-loop structure in the mRNA.
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