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Sharma, R. K.

Publications and source records attributed to Sharma, R. K..

2 recordsLinked to original sources

Spatial variation in population-density of snow leopards in a multiple use landscape in Spiti Valley, Trans-Himalaya

The endangered snow leopard Panthera uncia occurs in human use landscapes in the mountains of South and Central Asia. Conservationists generally agree that snow leopards must be conserved through a land-sharing approach, rather than land-sparing in the form of strictly protected areas. Effective conservation through land-sharing requires a good understanding of how snow leopards respond to human use of the landscape. Snow leopard density is expected to show spatial variation within a landscape because of variation in the intensity of human use and the quality of habitat. However, snow leopards have been difficult to enumerate and monitor. Variation in the density of snow leopards remains undocumented, and the impact of human use on their populations is poorly understood. We examined spatial variation in snow leopard density in Spiti Valley, an important snow leopard landscape in India, via spatially explicit capture recapture analysis of camera trap data. We camera trapped an area encompassing a minimum convex polygon of 953 km2. We estimated an overall density of 0.49 (95% CI: 0.39-0.73) adult snow leopards per 100 km2. Using AIC, our best model showed the density of snow leopards to depend on wild prey density, movement about activity centres to depend on altitude, and the expected number of encounters at the activity centre to depend on topography. Models that also used livestock biomass as a density covariate ranked second, but the effect of livestock was weak. Our results highlight the importance of maintaining high density pockets of wild prey populations in multiple use landscapes to enhance snow leopard conservation.

ecology

Protective efficacy of calcium phosphate nanoparticle adsorbed bivalent subunit vaccine of Pasteurella multocida against homologous challenge in mice

Swine pasteurellosis, caused by Pasteurella multocida capsular types A and D, causes heavy economic loss to the pig farmers. The vaccine presently used is abacterin of Pasteurella multocida capsular type B that is proven to be effective against bovine pasteurellosis. However, its efficacy against swine pasteurellosis is questionable. The present study was carried out to evaluate the efficacy of calcium phosphate nanoparticle adjuvanted bivalent subunit vaccine prepared from Pasteurella multocida capsular types A and D along with a monovalent subunit vaccine prepared from Pasteurella multocida capsular type B in mice. The Alum precipitated bacterin vaccine was used as the control. The bivalent subunit vaccine comprising the immune components of both the capsular types showed significantly higher IgG response than either of the other two vaccines. Both the calcium phosphate nanoparticle adjuvanted vaccines could elicit 100% protection in mice against homologous challenges but the aluminum hydroxide adjuvanted bacterin vaccine could not elicit significant protection. Based on this preliminary work, it was concluded that the bivalent subunit vaccine would be a better option for immunization of swine against swine pasteurellosis. IMPORTANCE OF THE WORKThe swine pasteurellosis is an important economic disease affecting the pig population in the North-eastern part of India that contributes the major pig population. The disease is caused by Serotype A and D of Pasteurella multocida. At present the inactivated vaccine is used that is actually developed against P52 strain of serotype B:2 of Pasteurella multocida, which is mainly involved in haemorrhagic septicaemia (or bovine pasteurellosis) that affects the cattle, buffaloe, sheep and goat. As a result, the present vaccine does not give sufficient protection in pigs but gives significant protection in cattle, buffaloe, sheep and goat. Hence, there is a need of development of vaccine that can address specifically swine pasteurellosis by targeting serotype A and D of Pasteurella multocida.

microbiology