Evaluation of the multitest medium for rapid presumptive identification of Vibrio cholerae from environmental sources

The multitest V. cholerae medium (VC medium) for rapid presumptive identification of Vibrio cholerae was evaluated. On the basis of reactions in the VC medium, 379 strains recovered during a yearlong ecological study in Calcutta were presumptively identified as V. cholerae. Further phenotypic characterization of these strains revealed that the reactions of 371 (97.9%) isolates were consistent with that of V. cholerae. False-positive reactions were exhibited by eight (2.1%) strains, three of which were identified as Vibrio fluvialis biotype 1. By slightly varying the basic formulation of the VC medium, we could eliminate some false-positive reactions. On the basis of the present evaluation, we recommend the routine use of the VC medium.     

Enhanced anaerobic digestion of cellulose by intermittent floc-dispersion at 55°C

Summary The thermophilic (55°C) bioconversion of cellulose (-floc) to volatile fatty acids ceased prior to completion at high cellulose concentrations. This was attributable to the formation of large aggregates of partially digested cellulose which resulted in mass transfer limitations. Mechanical re-dispersion of cellulose enhanced the acid production. The total acid concentration increased from 4.18 g/L volatile acids (control) to 6.92 g/L after two blendings.     

Preference for meat is not innate in dogs

Indian free-ranging dogs live in a carbohydrate-rich environment as scavengers in and around human settlements. They rarely hunt and consequently do not encounter rich sources of protein. Instead, they have adapted to a diet of primarily carbohydrates. As descendents of the exclusively carnivorous wolves, they are subjected to the evolutionary load of a physiological demand for proteins. To meet their protein needs, they resort to a Rule of Thumb—if it smells like meat, eat it. Pups face high competition from group and non-group members and are in a phase of rapid growth with high protein demands. Following the Rule of Thumb, they can acquire more protein at the cost of increased competition and reduced supplementary non-protein nutrition. However, if the mother supplements their diet with protein-rich regurgitates and/or milk, then the pups can benefit by being generalists. Using a choice test in the field, we show that, while adults have a clear preference for meat, pups have no such preference, and they even eagerly eat degraded protein. Thus, the Rule of Thumb used by adult dogs for efficient scavenging is not innate and needs to be learned. The Rule of Thumb might be acquired by cultural transmission, through exposure to meat in the mother’s regurgitate, or while accompanying her on foraging trips.     

Effect of glucagon on alanine 2-oxoglutarate aminotransferase

Alanine-2-oxoglutarate aminotransferase activity in mouse liver is stimulated by the intravenous injection of glucagon. The stimulation is abolished by pretreatment with actinomycin D indicating that the increased activity is probably due to new enzyme formation. Administration of dibutyryl cyclic AMP, isoproterenol, an activator of adenyl cyclase and theophylline, an inhibitor of phosphodiesterase also increases the enzyme activity suggesting the involvement of cyclic AMP in glucagon-mediated increase of enzyme activity.