Iridoviruses have been associated with severe disease and economic loss in farmed food fish and ornamental fish, with mortality often reported to reach 50% or more. In the present study, three tropical marine food fish species and four tropical freshwater ornamental fish species with systemic iridovirus infections were examined histopathologically and ultrastructurally. Light microscopy consistently revealed pale to intensely basophilic hypertrophied virus-infected cells in spleen, kidney and intestine from all seven species. Ultrastructural examination showed changes in the vascular endothelium overlying hypertrophied virus-infected cells suggestive of pressure necrosis. Viral isolation was improved by the use of fibroblastic cell lines. This, together with the sub-endothelial location of infected cells in all infected species examined, suggests that systemic iridoviruses are mesotheliotropic.

Animals↗

PubMedDate not supplied

Fundamental frequency, intensity, and vowel duration characteristics related to perception of Cantonese alaryngeal speech.

Fundamental frequency (F(0)), F(0) contours, vowel duration, and intensity associated with Cantonese alaryngeal speech, and their relation to the perception of meaning were studied. Thirty adult male native Cantonese speakers participated in the study: 10 esophageal, 10 electrolaryngeal, and 10 laryngeal speakers. Results indicated that perceptually, listeners were able to identify what the Cantonese esophageal speakers were saying, particularly for words associated with high-level, low-falling and high-rising tonal contours. Acoustic analysis of the speech signals of the esophageal speakers indicated that intensity and durational data did not contribute to the perception of meaning. The F(0) contours appeared to be the acoustic cues associated with the signal that contributed most to the perception of meaning.

Adult↗