Single- and few-moded lithium aluminosilicate optical fiber for athermal Brillouin strain sensing.

Results are presented toward realizing a true single-mode fiber whose Brillouin frequency shift is independent of temperature, while its dependence on strain is comparable to conventional high-silica-content single-mode fibers. Demonstrated here is a fiber with a negative thermal sensitivity dν/dT of -0.26 MHz/K and a strain sensitivity of +406 MHz/%. The suppression of the Brillouin thermal response is enabled by the large thermal expansion coefficient of the group I oxide-containing silica glass network.

Challenge exposure of cattle vaccinated with a chemically altered strain of Pasteurella haemolytica.

Calves vaccinated with a chemically altered strain of Pasteurella haemolytica and their nonvaccinated controls were challenge exposed intranasally with the Cooper strain of infectious bovine rhinotracheitis virus. Five days later, the calves were challenge exposed intratracheally with the P haemolytica type A1. Calves that had been vaccinated with large, medium, or small doses of the chemically altered vaccinal strain of P haemolytica had various degrees of resistance to the experimental challenge exposure. Nonvaccinated animals developed severe respiratory tract disease and pneumonia after challenge exposure.

Cross-protection by a chemically altered vaccinal strain of Pasteurella multocida in mice and hamsters.

A chemically altered type A strain of Pasteurella multocida was used to vaccinate mice and hamsters. The vaccinated animals were challenge exposed with type A, B, and E isolated of P multocida. A degree of protection was afforded the vaccinated animals against homologous and heterologous challenge-exposure strains.

Studies on the antigenicity of an inactivated, aluminum hydroxide adjuvant equine influenza vaccine.

An inactivated, aluminum hydroxide adjuvant equine influenza vaccine was tested in horses and guinea pigs to determine the levels of antigen that would elicit maximum serological responses. Vaccine containing serial twofold increments of A/Equi-1/Prague and A/Equi-2/Miami strains of equine influenza virus was administered to random groupings of both types of test animals. The hemagglutination inhibition antibody response for each group was then measured. Results in horses and guinea pigs were compared to determine if the equine serological values could be related to a potency test in laboratory animals. The highest mean hemagglutination inhibition antibody response in horses occurred in groups vaccinated, respectively, with 128 or 256 hemagglutination units of A/Equi-1 and 512 or 1024 hemagglutination units of A/Equi-2 antigen. Groups vaccinated with further two- or fourfold increases in these antigens had mean hemagglutination inhibition titers that were somewhat lower than the maximum levels. When graded doses of vaccine were given to guinea pigs, their hemagglutination inhibition antibody titers reached a plateau of maximum values, similar to the serological response in vaccinated horses. Test horses remained clinically free from signs of equine influenza during the year following vaccination and no untoward post-vaccination reactions were observed.