Abstract: The present invention relates to chimeric pestiviruses having utility as immunogenic compositions and vaccines. Also described herein are methods and kits for treating or preventing the spread of bovine viral diarrhea virus infection, as well as methods and kits for differentiating between vaccinated and wild-type infected animals.

Abstract: The present invention provides safe vaccines and methods of preparing such vaccines. The vaccines of the present invention contain at least two live mutant viruses of the same family or nucleic acid molecules encoding such viruses, wherein each of the two viruses or the encoding nucleic acids contains a mutation that confers a desirable phenotype and the mutations in the viruses reside in the same genomic site such that the mutant viruses cannot recombine with each other to eliminate the mutations.

Abstract: The present invention provides safe vaccines and methods of preparing such vaccines. The vaccines of the present invention contain at least two live mutant viruses of the same family or nucleic acid molecules encoding such viruses, wherein each of the two viruses or the encoding nucleic adds contains a mutation that confers a desirable phenotype and the mutations in the viruses reside in the same genomic site such that the mutant viruses cannot recombine with each other to eliminate the mutations.

Abstract: A method and system for preventing a visual video copy being made of a projected image on a screen. In a theater or television or computer screen environment, an image is displayed on a screen by a film projector or a video projector or by the cathode ray tube or the LCD screen. A form of piracy is accomplished by copying the image on the screen with a video camcorder or camera. This invention seeks to produce visual presentations which invention inhibits off-screen copying by camcorders or cameras. A preferred embodiment of the invention comprises of recording means which records images at variable frame rates which rates are either pre-programmed or decided by the user of the means. The variation of the frame rates forms a rate sequence which is recorded simultaneously when the images are recorded. The rate sequence will be read by the display device when the recorded images are displayed such that the images are displayed at the frame rates at which they are recorded.

Abstract: Discussed is a process for preventing clathrate hydrate masses from detrimentally impeding the possible flow of a fluid susceptible to clathrate hydrate formation. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member, six member and/or seven member cyclic chemical groupings. Additives include polymers having lactam rings. Additives can also contain polyelectrolytes that are believed to improve conformance of polymer additives through steric hinderance and/or charge repulsion. Also, polymers having an amide on which a C.sub.1 -C.sub.4 group is attached to the nitrogen and/or the carbonyl carbon of the amide may be used alone, or in combination with ring-containing polymers for enhanced effectiveness.