ABSTRACT
Quantifying and understanding the impact of anthropogenic sound on marine mammals has been the focus of many researchers both in laboratory settings as well as in the field. This study presents the audiogram of a sub-adult Blainville's beaked whale that stranded in Hawaii. The hearing measurements were conducted using the non-invasive auditory brainstem response technique. A total of 11 sinusoidally amplitude modulated tones were tested ranging from 5.6 to 160 kHz. The audiogram data indicated that the region of best hearing was found between 40 and 50 kHz with thresholds below 50 dB. This frequency range partially overlaps with the frequency modulated upsweep that Blainville's beaked whales have been reported to use during echolocation. These results match the frequency range obtained from the hearing measurements of a Gervais' beaked whale previously tested using contact acoustic stimulation and emphasize the importance of obtaining rapid hearing measurements on live stranded animals to improve the understanding of poorly known species.
Subject(s)
Audiometry , Evoked Potentials, Auditory/physiology , Whales/physiology , Acoustic Stimulation , Animals , Auditory Threshold/physiology , Fourier Analysis , MaleABSTRACT
OBJECTIVE: To identify potential sources of human Mycobacterium bovis infection in Bobo-Dioulasso, Burkina Faso. METHODS: A tuberculin survey among 174 cattle was performed. Mycobacteriologic identification in 64 samples of pooled milk, and in 199 tissue samples collected from the slaughterhouse of Bobo-Dioulasso, Burkina Faso, was also done. We retrospectively analyzed the distribution of tuberculosis (TB) cases on 1140 clinical records according to professional occupation and to ethnic group. The frequency of pulmonary and extrapulmonary TB was related to potential exposure and route of transmission of M. bovis from animals. RESULTS: Out of six herds (total 170 bovines), only one was free of any positive tuberculin test. Among 199 bovines which had been slaughtered over four consecutive nights, 38 (19%) had morphologic lesions suggestive of TB; 17 (45%) of those were positive for acid-fast bacilli by microscopic examination on one of their lesions, and 20 samples (53%) presented a positive culture for a pathogenic mycobacterium, including M. bovis and M. tuberculosis. In the retrospective analysis, Peuls more frequently had a pulmonary form of disease. This may be related to the route of transmission. CONCLUSIONS: Attention has to be paid to human TB of bovine origin in Burkina Faso. The identification of M. tuberculosis in milk and in tissue samples raises the question of the transmission of TB from humans to cattle.
ABSTRACT
Several wheats (Triticum aestivum L. em Thell.) containing the short arm of chromosome 1R from rye (Secale cereale L.) translocated to the long arm of wheat chromosome 1B were examined, by in situ hybridization with a biotinylated probe, for the expression of rye rRNA genes located in the nucleolus-organizing region (NOR) present on the short arm of 1R. The wheats analyzed contain a reduced rye NOR band, identified by a C-banding technique, that was assumed to have resulted from a deletion that reduced the number of rRNA genes and spacer units. Genes being actively transcribed could be recognized as dispersed label on DNA within the nucleolus, while those genes that were inactive were seen as condensed label. After in situ hybridization with a biotinylated rye NOR spacer probe, no evidence of rye rRNA gene activity was detected in the plants containing a reduced rye NOR band. Biotin-labeling of chromosomes containing a normal-sized rye NOR locus showed a degree of rye activity consistent with the results of a previous study that used a radioactive probe detected by autoradiography. It was determined previously that rye rRNA genes in a wheat background show significantly less activity than in diploid rye because the spacer units between the rRNA genes of rye are smaller than those of wheat, and in cereals the ribosomal locus with the larger spacer unit is preferentially transcribed. The present results indicate that the number of spacer units is also important in determining which NOR locus (i.e., rye or wheat) will be expressed when several ribosomal loci are present in a wheat background.
