Approximate ab initio calculation of vibrational properties of hydrogenated amorphous silicon with inner voids

We have performed an approximate ab initio calculation of vibrational properties of hydrogenated amorphous silicon (a-Si:H) using a molecular dynamics method. A 216 atom model for pure amorphous silicon (a-Si) has been employed as a starting point for our a-Si:H models with voids that were made by removing a cluster of silicon atoms out of the bulk and terminating the resulting dangling bonds with hydrogens. Our calculation shows that the presence of voids leads to localized low energy (30-50 cm^{-1}) states in the vibrational spectrum of the system. The nature and localization properties of these states are analyzed by various visualization techniques.Comment: 15 pages with 6 PS figures, to appear in PRB in December 199

StreptInCor: a candidate vaccine epitope against S. pyogenes infections induces protection in outbred mice.

Infection with Streptococcus pyogenes (S. pyogenes) can result in several diseases, particularly in children. S. pyogenes M protein is the major virulence factor, and certain regions of its N-terminus can trigger autoimmune sequelae such as rheumatic fever in susceptible individuals with untreated group A streptococcal pharyngitis. In a previous study, we utilized a large panel of human peripheral blood cells to define the C-terminal protective epitope StreptInCor (medical identity), which does not induce autoimmune reactions. We recently confirmed the results in HLA-transgenic mice. In the present study, we extended the experimental assays to outbred animals (Swiss mice). Herein, we demonstrate high titers of StreptInCor-specific antibodies, as well as appropriate T-cell immune responses. No cross-reaction to cardiac myosin was detected. Additionally, immunized Swiss mice exhibited 87% survival one month after challenge with S. pyogenes. In conclusion, the data presented herein reinforce previous results in humans and animals and further emphasize that StreptInCor could be an effective and safe vaccine for the prevention of S. pyogenes infections

StreptInCor did not induce T-cell cross reactivity against cardiac myosin.

<p>Splenocytes from Swiss mice (n = 6) immunized with 10 µg of StreptInCor adsorbed onto 60 µg of aluminum hydroxide (black symbols) or injected with aluminum hydroxide alone (controls, open symbols) were incubated with StreptInCor at 1 µg/mL (circles), 10 µg/mL (triangles) or cardiac myosin (diamonds). Stimulation indices ≥2.0 (dotted line) were considered positive. Each data point represents a sample, and the line represents the mean. <i>P</i> values: ** (≤0.01).</p

StreptInCor promotes long-lasting survival.

<p>Swiss mice (n = 15) from three independent experiments immunized with 10 µg of StreptInCor adsorbed onto 60 µg of aluminum hydroxide (black circles) were protected against <i>S. pyogenes</i> infection in comparison to controls (n = 15) that received only the adjuvant (open circles). The log rank test showed that differences between StreptInCor-immunized Swiss and control groups were statistically significant (<i>P</i><0.05).</p

Whose shoe fits best? Dubious physics and power politics in the TMD footprint controversy

Apparent design breakthroughs in short-range missile defense systems such as Theater High-Altitude Air Defense (THAAD) have prompted questions about the legality of such systems under the 1972 Antiballistic Missile (ABM) Treaty. Prominent physicists have used computer “footprint” methodology to prove that if engineered to specifications, THAAD might exceed ABM Treaty performance limits banning highly effective missile defense systems. In response, missile defense officials commissioned Sparta, Inc. to conduct secret research casting doubt on the validity of such findings. The substantial diplomatic issues at stake and the interesting rhetorical dynamics involved in this dispute warrant close scholarly analysis. Attention to the iterative relationship between the interpenetrating spheres of public argument and scientific practice in this case yields novel insight about the processes in which technical knowledge of defense systems is forged and raises fresh issues for the “closure project” in science and technology controversy studies