Design and Testing of Improved Spacesuit Shielding Components

In prior studies of the current Shuttle Spacesuit (SSA), where basic fabric lay-ups were tested for shielding capabilities, it was found that the fabric portions of the suit give far less protection than previously estimated due to porosity and non-uniformity of fabric and LCVG components. In addition, overall material transmission properties were less than optimum. A number of alternate approaches are being tested to provide more uniform coverage and to use more efficient materials. We will discuss in this paper, recent testing of new material lay-ups/configurations for possible use in future spacesuit designs

Prevention and treatment of Clostridium perfringens epsilon toxin intoxication in mice with a neutralizing monoclonal antibody (c4D7) produced in Nicotiana benthamiana

Epsilon toxin (ETX), produced by Clostridium perfringens types B and D, is among the most lethal toxins known. ETX is a potential bioterrorism threat that was listed as a Category B agent by the U.S. Centers for Disease Control until 2012 and it still remains a toxin of interest for several government agencies. We produced a monoclonal antibody (MAb) against ETX (ETX MAb c4D7) in Nicotiana benthamiana and characterized its preventive and therapeutic efficacy in mice. The ETX preparation used was highly lethal for mice (LD(50) =1.6 μg/kg) and resulted in a mean time from inoculation to death of 18 and 180 minutes when administered intravenously or intraperitoneally, respectively. High lethal challenge resulted in dramatic increases of a variety of pro-inflammatory cytokines in serum, while lower, but still lethal doses, did not elicit such responses. ETX MAb c4D7 was highly effective prophylactically (ED(50) = 0.3 mg/kg; ED(100) = 0.8 mg/kg) and also provided protection when delivered 15-30 minutes post-ETX intoxication. These data suggest that ETX MAb c4D7 may have use as a pre- and post-exposure treatment for ETX intoxication

Secondary Neutron-Production Cross Sections from Heavy-Ion Interactions between 230 and 600 MeV/nucleon

Secondary neutron-production cross-sections have been measured from interactions of 230 MeV/nucleon He, 400 MeV/nucleon N, 400 MeV/nucleon Kr, 400 MeV/nucleon Xe, 500 MeV/nucleon Fe, and 600 MeV/nucleon Ne interacting in a variety of elemental and composite targets. We report the double-differential production cross sections, angular distributions, energy spectra, and total cross sections from all systems. Neutron energies were measured using the time-of-flight technique, and were measured at laboratory angles between 5 deg and 80 deg. The spectra exhibit behavior previously reported in other heavy-ion-induced neutron production experiments; namely, a peak at forward angles near the energy corresponding to the beam velocity, with the remaining spectra generated by preequilibrium and equilibrium processes. The double-differential spectra are fitted with a moving-source parameterization. Observations on the dependence of the total cross sections on target and projectile mass are discussed