The influence of incorporation of the dopants with proton-acceptor properties into perfluorosulfonic acid cation exchange membranes (MF-4SC and Nafion), and their treatment conditions on the characteristics of Donnan potential (DP)-sensors (analytical signal is the Donnan potential) in the aqueous solutions containing asparaginate and potassium ions in a wide pH range was investigated. A silica, surface modified by 3-aminopropyl and 3-(2-imidazolin-1-yl)-propyl groups, was used as the dopant. The membranes were subjected to mechanical deformation and thermal treatment at various relative humidities.
View Article and Find Full Text PDFThe potential for vocal modification in mammals has recently been of great interest. This study focuses on the potential for vocal matching in juvenile and adolescent goitred gazelles Gazella subgutturosa that were group housed as part of an animal management programme. Two groups of animals (16 and 19 unrelated individuals, respectively) were recorded at two different ages, juvenile and adolescent, regarding 20-25 calls per individual per age; each group was evaluated in a separate year.
View Article and Find Full Text PDFIndividualistic voices are important for establishing personalized relationships among individuals. In young animals, individual vocal identity is affected by permanent changes of the acoustics due to the growth of their vocal apparatus. Different acoustic variables change uncoordinatedly, so vocal individuality should be repeatedly upgraded along development.
View Article and Find Full Text PDFIn goitred gazelles (Gazella subgutturosa), sexual dimorphism of larynx size and position is reminiscent of the case in humans, suggesting shared features of vocal ontogenesis in both species. This study investigates the ontogeny of nasal and oral calls in 23 (10 male and 13 female) individually identified goitred gazelles from shortly after birth up to adolescence. The fundamental frequency (f0) and formants were measured as the acoustic correlates of the developing sexual dimorphism.
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