Does vocal learning accelerate acoustic diversification? Evolution of contact calls in Neotropical parrots.

Learning has been traditionally thought to accelerate the evolutionary change of behavioural traits. We evaluated the evolutionary rate of learned vocalizations and the interplay of morphology and ecology in the evolution of these signals. We examined contact calls of 51 species of Neotropical parrots from the tribe Arini. Parrots are ideal subjects due to their wide range of body sizes and habitats, and their open-ended vocal learning that allows them to modify their calls throughout life. We estimated the evolutionary rate of acoustic parameters of parrot contact calls and compared them to those of morphological traits and habitat. We also evaluated the effect of body mass, bill length, vegetation density and species interactions on acoustic parameters of contact calls while controlling for phylogeny. Evolutionary rates of acoustic parameters did not differ from those of our predictor variables except for spectral entropy, which had a significantly slower rate of evolution. We found support for correlated evolution of call duration, and fundamental and peak frequencies with body mass, and of fundamental frequency with bill length. The degree of sympatry between species did not have a significant effect on acoustic parameters. Our results suggest that parrot contact calls, which are learned acoustic signals, show evolutionary rates similar to those of morphological traits. This is the first study to our knowledge to provide evidence that change through cultural evolution does not necessarily accelerate the evolutionary rate of traits acquired through life-long vocal learning.

Estudios iniciales para el desarrollo de procesos en la produccion de vacunas bacterianas por cultivo agitado. / Initial studies to develop a process in the production of bacterial vaccines by means of agitated culture

En el presente trabajo se hacen estudios preliminares para establecer el cultivo agitado de Corynebacterium diphteriae y Bordetella pertussis, usando las cepas que se emplean en cultivo estacionario y algunas ya adaptadas a este tipo de cultivo o para aumentar la produccion de DPT en el Instituto Nacional de Higiene. Se establecieron las condiciones generales de propagacion en el matraz y en el fermentador de 14 litros. En el caso de C. diphteriae se logro obtener en el matraz de 500 ml hasta 142 Lf/ml y en el de B. pertussis se obtuvieron rendimientos de 30.4 UO/ml en el fermentador de 14 litros. Los resultados se obtuvieron en 48 horas de proceso

Estudio comparativo de los medios de cultivo HBP-2 y FGP-1 en la produccion de Bordetella pertussis por fermentacion. / Comparative study of culture media HBP-2 and FGP-1 in the production of Bordetella pertussis by fermentation

Se compararon dos medios de cultivo utilizados en el Instituto Nacional de Higiene para la produccion de vacuna pertussis. El medio FGP-1 produce 30% mayor opacidad, en menor tiempo y a mas bajo costo que el medio HBP-2. Ambos medios producen lotes de potencia semejante