Reference-wave solutions for high-frequency fields propagating in random media.

Ray theory plays an important role in determining the propagation properties of high-frequency fields and their statistical measures in complicated random environments. According to the ray approach, the field at the observer can be synthesized from a variety of field species arriving along multiple ray trajectories resulting from refraction and scattering from boundaries and from scattering centers embedded in the random medium. For computations of the statistical measures, it is desirable therefore to possess a solution for the high-frequency field propagating along an isolated ray trajectory.

Response of immunocompetent and immunosuppressed Spodoptera littoralis larvae to baculovirus infection.

The Mediterranean lepidopteran pest Spodoptera littoralis is highly resistant to infection with the Autographa californica multiple nucleopolyhedrovirus (AcMNPV) via the oral route, but highly sensitive to infection with budded virus (BV) via the intrahaemocoelic route. To study the fate of AcMNPV infection in S. littoralis, vHSGFP, an AcMNPV recombinant that expresses the reporter green fluorescent protein gene under the control of the Drosophila heat-shock promoter, and high-resolution fluorescence microscopy were utilized.

Reference-wave solution for the two-frequency propagator in a statistically homogeneous random medium.

Spatial and temporal structures of ultrawide-band high-frequency fields can be appreciably affected by random changes of the medium parameters characteristic of almost all geophysical environments. The dispersive properties of random media cause distortions in the propagating signal, particularly in pulse broadening and time delay. Theoretical analysis of pulsed signal propagation is usually based on spectral decomposition of the time-dependent signal and the analysis of the two-frequency mutual coherence function.

Reference-wave solutions for the high-frequency field in random media.

Ray trajectories, as has been shown in the recently formulated stochastic geometrical theory of diffraction, play an important role in determining the propagation properties of high-frequency wave fields and their statistical measures in complicated random environments. The field at the observer can be presented as the superposition of a variety of field species arriving at the observer along multiple ray trajectories resulting from boundaries and scattering centers embedded into the random medium. In such situations the intensity products from which the average intensity measures can be constructed and which, in general, are presented as even products of the total field, will contain sums of products of mixed field species arriving along different ray trajectories.