RESUMEN
Unexpected errors in methane measurement by gas chromatography occurred when samples at thermophilic temperatures were analyzed. With a standard curve prepared at room temperature (25 degrees C), stoppered bottles incubated and sampled at 37 to 85 degrees C showed more methane upon analysis than bottles incubated at 25 degrees C: values at 50, 63, and 85 degrees C were 109, 126, and 125%, respectively, of the 25 degrees C value. All variation between 4 and 50 degrees C can be explained by the temperature difference between culture bottle and sampling syringe, and the variation of methane concentration can be predicted by the gas law. Between 50 and 63 degrees C, there was a more dramatic rise than predicted by theory. These variations are important to consider if thermophilic methane production is to be measured accurately. Methods to avoid errors are discussed.
RESUMEN
The immunity and protective capability produced by vaccines can vary remarkably according to the kinds of adjuvants being used. In the case of foot-and-mouth disease (FMD) vaccines in pigs, only oil-adjuvant vaccines have been used, and these tend to show lower immunity in pigs than in cattle. New adjuvants for these vaccines are therefore needed. We made different experimental FMD vaccines using new adjuvants (ISA 201, Carbigen, Emulsigen-D) and well-known adjuvants (ISA 206, aluminum hydroxide gel) and then conducted tests to compare the enhancement in pig immunity. More effective immune responses and protection against challenge were observed with the new adjuvants Emulsigen-D and ISA 201 compared to existing adjuvants. In the case of dairy goats, a mixture of Emulsigen-D and aluminum hydroxide gel produced rapid neutralizing antibody responses that were similar to results from tests conducted with pigs.