Comparative study of macrophage migration in different strains of mice: absence of migration in C3H mice.
In the course of studying the susceptibility of mice to Salmonella infection, we discovered that C3H/HeJ mice differ from other strains in both their susceptibility to infection and their response to prior vaccination. Others have noted the absence of the usual B cell stimulation by LPS in these mice. To investigate the status of delayed hypersensitivity in C3H/HeJ mice, we tried to use the technique of macrophage migration. Under conditions of normal migration for other strains, C3H/HeJ peritoneal and splenic macrophages failed to migrate, thus establishing another differentiating immunological trait for this strain.
External injection of an electron bunch in the laser wakefield can result in femtosecond accelerated bunches with relatively low energy spread. In this paper it is shown that the density transition from vacuum to plasma can play an important role in the trapping process. The plasma wavelength in this transition region changes continuously, which means that the injected electrons see an altering wakefield. This can result in strong defocusing of the injected bunch. It is found that the effect becomes stronger for stronger wakefields, longer transition lengths, and lower injection energies. The transition region can be avoided if the bunch is injected into the wakefield at an angle. Injecting the bunch at an angle allows the bunch to be wider and results in more charge being trapped. The dynamics of the bunch in this case are similar to the dynamics of a bunch injected in front of the laser pulse