Serologic Evidence for Selected Infectious Diseases in Marsican Brown Bears (Ursus arctos marsicanus) in Italy (2004-09)
JOURNAL OF WILDLIFE DISEASES
Authors: Di Francesco, Cristina Esmeralda; Gentile, Leonardo; Di Pirro, Vincenza; Ladiana, Lara; Tagliabue, Silvia; Marsilio, Fulvio
Abstract
We tested 30 serum samples collected during 2004-09 from 22 free-ranging Marsican brown bears (Ursus arctos marsicanus) in the National Park of Abruzzo, Lazio, and Molise, Italy, for antibodies against canine distemper virus (CDV), canine adenovirus type 2 (CAV-2), canine parvovirus type 2 (CPV-2), Brace lla spp., and eight Leptospira interrogans sensu lato serovars. Antibody to CDV was detected in 11 samples (37%); only two bears (10%) had detectable CAV-2 and Brace lla spp. antibodies; three bears were positive for L. interrogans serovar Bratislava; and one sample had antibody against L. interrogans serovar Copenhageni. All samples were positive for CPV-2 antibody. The CPV-2 antibody titers varied from 1:640 to 1:10,240, suggesting that transmission was still active. Fifty percent of bears were positive for antibody to two or more pathogens. Our results highlight the need to consider infectious diseases as a potential risk for Marsican brown bear conservation.
Numerical Analysis and Demonstration: Transmission Shaft Influence on Meshing Vibration in Driving and Driven Gears
SHOCK AND VIBRATION
Authors: Xu Jinli; Su Xingyi; Peng Bo
Abstract
The variable axial transmission system composed of universal joint transmission shafts and a gear pair has been applied in many engineering fields. In the design of a drive system, the dynamics of the gear pair have been studied in detail. However few have paid attention to the effect on the system modal characteristics of the gear pair, arising from the universal joint transmission shafts. This work establishes a torsional vibration mathematical model of the transmission shaft, driving gear, and driven gear based on lumped masses and the main reducer system assembly of a CDV (car-based delivery vehicle) car. The model is solved by the state space method. The influence of the angle between transmission shafts and intermediate support stiffness on the vibration and noise of the main reducer is obtained and verified experimentally. A reference for the main reducer and transmission shaft design and the allied parameter matching are provided.