Evidence of Color Coherence Effects in W+jets Events from ppbar Collisions at sqrt(s) = 1.8 TeV

We report the results of a study of color coherence effects in ppbar collisions based on data collected by the D0 detector during the 1994-1995 run of the Fermilab Tevatron Collider, at a center of mass energy sqrt(s) = 1.8 TeV. Initial-to-final state color interference effects are studied by examining particle distribution patterns in events with a W boson and at least one jet. The data are compared to Monte Carlo simulations with different color coherence implementations and to an analytic modified-leading-logarithm perturbative calculation based on the local parton-hadron duality hypothesis.Comment: 13 pages, 6 figures. Submitted to Physics Letters

Cellular and humoral immune responses to poliovirus in mice: a role for helper T cells in heterotypic immunity to poliovirus

Immunization of BALB/c mice with a single dose of the Sabin type 1, type 2 or type 3 poliovirus vaccine strains stimulated cross-reactive T helper cell responses detected by both in vitro proliferation and interleukin (IL)-2/IL-4 production. Although the polyclonal T cell responses were cross-reactive, the results also suggest that a proportion of the T cells were directed against serotype-specific determinants. In contrast, neutralizing antibodies, assayed in the serum from the same animals, were predominantly serotype-specific and only reached significant titres after secondary immunization. A comparison of the immunogenicity of poliovirus administered subcutaneously in Freund's complete adjuvant or intraperitoneally as an alum precipitate or without adjuvant, showed that optimum responses were obtained by immunization with virus in the presence of alum. An examination of the effect of heterotypic priming showed that immunization with type 2 virus primed for a secondary antibody response to each of the three serotypes, whereas priming with type 1 or type 3 viruses could only generate a secondary antibody response to the homologous virus or to type 2 virus

Aerosol measles vaccination in macaques: Preclinical studies of immune responses and safety

The comparative efficacy and safety of measles vaccination via the aerosol route versus subcutaneous injection has not been fully resolved. We vaccinated cynomolgus monkeys (Macaca fascicularis) with the live-attenuated Edmonston-Zagreb measles virus (MV) vaccine and compared different routes of administration in the immunocompetent and the immunocompromised host. Immunogenicity and protective efficacy of aerosol vaccination using devices similar to those previously used in humans were comparable to those in animals vaccinated by injection. No evidence for a safety hazard associated with the route of vaccination was detected. The results of this study support further clinical evaluation of aerosol vaccination for measles