Fatal Intestinal Coccidiosis in a Three-Week-Old Buffalo Calf (Bubalus bubalus)
Abstract The water buffalo (Bubalus bubalus) is important to the economy of several countries, especially in Asia and South America. Little is known regarding the impact of coccidiosis in buffaloes. Cattle and buffaloes are considered to have common species of Eimeria, but critical cross-transmissions have not been made because it is difficult to raise these hosts coccidian free. Clinical coccidiosis was confirmed post mortem in a 22-day-old buffalo calf that died after a 3- to 4-day illness. Oocysts morphologically identical to Eimeria bareillyi were found in the feces and in sections of small intestine. Oocysts were often pyriform, sometimes with asymmetrical sides. The shorter end was flattened and approximately 5–6 μm wide. Unsporulated oocysts in feces were 23.2–29.5 × 16.5–22 μm, with an average of 27.2 × 19.3 μm. Schizonts, gamonts, and oocysts were identified in sections of small intestine where they were located in enterocytes of the jejunum and ileum. No coccidian stages were seen in sections of colon. This is one of the first confirmed cases of clinical coccidiosis in water buffalo.
Proposed life cycle of Eimeria zuernii.
SUMMARY Ten bull calves, three months old or less, were infected with oocysts of Eimeria zuernii. At post-mortem examination large schizonts were found in the lower ileum and small schizonts were present in the colon and caecum. Gametogony occurred in the colon and caecum. The life cycle of E. zuernii apparently contains at least two schizogonous generations before gametogony.
Modelling of Mooney viscosity relaxation in natural rubber
Abstract Better assessment of natural rubber (NR) quality and processability, through the identification of new attributes, is still a major challenge. With this scope, 12 model samples of natural polyisoprene and two of synthetic polyisoprene were characterized in terms of Mooney torque relaxation, using the standardized ISO289 method (ML(1+4)100, explained later in the Section 1 ). The main purpose of this study was to identify a model that gave a better fit for the experimental decay of Mooney torque over time (ML(t)=f(t)) than the usual power law model used before (Y=at−b, [G.M. Bristow, A.G. Sears, The use of novel parameters in the assessment of natural rubber processability, NR Technol. 18 (1987); H.G. Burhin, W. Spreutels, J.M. Campbell, MV2000 Mooney viscometer: Mooney relaxation measurements on raw polymers and compounded rubber stocks, Kautsch. Gummi Kunstst. 43 (1990) 431]). The results showed that a generalized Maxwell model, and the Wu–Abbott empirical model ( Y = 1 − a Ln ( t ) − ( b t / ( c + t ) ) ) [T. Wu, J.A. Abbott, Firmness and force relaxation characteristics of tomatoes stored intact or as slices, Postharvest Biol. Technol. 24 (2002) 59–68], recently used for describing stress relaxation of tomato flesh, allowed a better description of the relaxation curve for the samples studied than the power law or stretched exponential traditionally used. Moreover, the total relaxation time (τm) given by the generalized Maxwell model showed good correlation with the total gel content of the samples studied.