Vaccination with novel low-molecular weight proteins secreted from Trichinella spiralis inhibits establishment of infection

Trichinella spiralis muscle stage larvae (mL1) produce excretory-secreted products (ESPs), a complex mixture of protein, which are believed to be important for establishing or maintaining an infection niche within skeletal muscle and the intestine. Studies of both whole ESPs and individual cloned proteins have shown that some ESPs are potent immunogens capable of eliciting protective immune responses. Here we describe two novel proteins, Secreted from Muscle stage Larvae SML-4 and SML-5 which are 15 kDa and 12 kDa respectively. The genes encoding these proteins are highly conserved within the Trichinellids, are constituents of mL1 ESP and localized in the parasite stichosome. While SML-5 is only expressed in mL1 and early stages of adult nematode development, SML-4 is a tyvosylated glycoprotein also produced by adult nematodes, indicating it may have a function in the enteral phase of the infection. Vaccination with these proteins resulted in an impaired establishment of adult stages and consequently a reduction in the burden of mL1 in BALB/c mice. This suggests that both proteins may be important for establishment of parasite infection of the intestine and are prophylactic vaccine candidates

Radiative Aerothermodynamics of Entering Space Vehicles: Toward the Use of State-to-State Approach

n/

A particle-in-cell/Monte Carlo model of the Ar

This article presents a particle-in-cell (PIC)/test-particle Monte Carlo (TPMC) simulation of the dynamics of Ar+ ions in the region (sheath and presheath) surrounding an attracting cylindrical Langmuir probe at medium He buffer gas pressure. The numerical model is based on a combination of PIC simulation for the ion component and fluid description for the electrons using the Boltzmann relation. The electric field is self-consistently computed via the Poisson equation. The neutrals are modeled directly by an analytical method. The elastic collisions between Ar+ ions and He atoms are accounted for using a TPMC method based on the polarization potential theory. The results of the present simulation are compared with measurements, with other probe theories and the results of other authors simulations

Very-near-field plume simulation of a stationary plasma thruster

The plasmadynamics of a stationary plasma thruster (SPT-100) plume in the very-near-field region have been studied by using a two-dimensional axisymmetric numerical code based on a combination of Particle-in-Cell (PIC) simulation for ion component (Xe+ and Xe++) and fluid description for electrons. In particular we have solved the electron momentum conservation equation (including collisional and magnetic effects) and the electron energy conservation equation (including collisional effects). Due to the difference between electron and ion Larmor radius and to the effect of the thruster wall, the quasi-neutrality hypothesis can be violated in the very-near-field plume region and the electric field must be computed accordingly. The xenon atom flowfield is calculated analytically. The model allows a unitary rationalization of several experimental observations