These results suggest that the efficient induction of RNAi using bacteria to deliver dsRNA is a possible method for management of CPB. This could be also a promising bioassay approach for genome-wide screens to identify effective target genes for use as novel RNAi-based insecticides.

Material properties and oxidation behavior of low-density felts used as substrates for conformal carbon/phenolic ablators were compared with those of a rigid carbon fiber preform used to manufacture heritage lightweight ablators. Synchrotron x-ray micro-tomography measurements were performed to characterize the materials' microstructure at the scale of the fibers. Using the

Current video cameras used to measure in situ root activities lack essential registration and identification components for repeated accurate measurements. This report describes a rapid, inexpensive and completely portable approach for controlling and identifying camera position when making repeated video recordings from minirhizotrons in large field experiments. These registration handle and microcomputer additions to an agricultural microvideo color camera provide new opportunities for measuring root and nodule development. Preliminary measurements indicated that corn roots appeared and disappeared to depths of 75 cm for different N treatments 86 to 99 d after planting. Additionally, root development, maturation, and death can be observed in situ throughout the root profile. These modifications offer a uniform method for comparing root turnover rates and other specific dynamics of the rhizosphere at 1.2‐cm intervals in contrasting soil and climatic conditions.

Oxidation is one of the main decomposition mechanisms of fibrous carbon/phenolic ablators employed in thermal protection systems for planetary entry capsules. The oxidation process is driven by two competing mechanisms: diffusion of reactants within the porous medium, and reaction rates at the surface of the fibers. These mechanisms are characterized by the Thiele number. Given that the Thiele number varies during an atmospheric entry, we aim to understand the effects of the diffusion/reaction processes on the decomposition of a porous carbon material in various regimes. We use a particle method for simulations of the oxidation process at microscale. The movement of oxygen reactants is simulated using a Brownian motion technique, and heterogeneous first-order reactions at the surface are modeled with a sticking probability law. To enable simulations of the fiber decomposition on actual materials, we use digitized computational grids obtained using X-ray microtomographic imaging. We present results for the oxidation of the substrate of the material used on the Mars Science Laboratory capsule that landed the Curiosity rover. We find that the depth of the reaction zone for this material is critically dependent on the Thiele number.

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