Bessel, Bessel-Gauss, and Gaussian beams have widely been investigated in optics in the paraxial approximation, under the frame of a scalar wave theory. Such approximations can hardly be applied in the microwave/millimeter-wave range, where the vectorial nature of the electromagnetic fields cannot be neglected, and experimental realizations for some of these beams appeared only recently. In this work, we discuss the generation of Bessel, Bessel-Gauss, and Gaussian beams through a fully vectorial electromagnetic approach. The field derivation of all these beams is first illustrated and numerical evaluations are then reported to compare their different propagation and diffractive behaviors. Finally, an innovative approach for realizing such solutions with planar microwave devices exploiting leaky waves is demonstrated through accurate numerical simulations.

In this study, the effect of exposing entomopathogenic bacteria isolated from macerated termite cadavers to varying intensities of a magnetic field for different periods of time on their pathogenic potential was examined; pathogenicity tests were carried out for each of the bacterial species. Two of the bacteria, Bacillus subtilis (Ehrenberg) Cohn and Serratia marcescens Bizio, were able to induce morbid effects on termites and both were re-isolated from the resulting cadavers. Reinfection using different concentrations of both bacteria was carried out on termites to determine the minimum lethal concentration required for pathogenicity. Bacillus subtilis was able to degenerate the termites at concentration values of 108 colony-forming units (cfu)/ml and S. marcescens at 107cfu/ml. Both bacteria were then exposed to magnetic fields of different intensities for different periods of time, after which they were used for reinfection of healthy termites. Post-infection study after the exposure of termites to magnetic field-treated bacterial cells revealed no reduction in the entomopathogenic potency of S. marcescens. As the extensive use of chemicals to control insect pests has been found to have detrimental effects on people and the environment, there is a pressing need to discover and develop new entomopathogens to control these insects biologically. Therefore, bacteria discovered in this study to have entomopathogenic potency against termites may be further studied and formulated into either powdery forms or suspensions to be applied to infested wood or wood products.

The purpose of this article is to set the context for this special issue of Disaster Medicine and Public Health Preparedness on the allocation of scarce resources in an improvised nuclear device incident. A nuclear detonation occurs when a sufficient amount of fissile material is brought suddenly together to reach critical mass and cause an explosion. Although the chance of a nuclear detonation is thought to be small, the consequences are potentially catastrophic, so planning for an effective medical response is necessary, albeit complex. A substantial nuclear detonation will result in physical effects and a great number of casualties that will require an organized medical response to save lives. With this type of incident, the demand for resources to treat casualties will far exceed what is available. To meet the goal of providing medical care (including symptomatic/palliative care) with fairness as the underlying ethical principle, planning for allocation of scarce resources among all involved sectors needs to be integrated and practiced. With thoughtful and realistic planning, the medical response in the chaotic environment may be made more effective and efficient for both victims and medical responders.

(Disaster Med Public Health Preparedness. 2011;5:S20-S31)

In this paper, we are concerned with the existence of multi-bump solutions for anonlinear Schrödinger equations with electromagnetic fields. We prove under some suitableconditions that for any positive integer m, there existsε(m) > 0 such that, for0 < ε < ε(m),the problem has an m-bump complex-valued solution. As a result, whenε → 0, the equation has more and more multi-bumpcomplex-valued solutions.

Mobile telephones are now an integral part of modern telecommunications. The widespread use of mobile telephones has given rise to concern about the potential influences of electromagnetic fields (EMFs) on human health. The effects of EMFs on human beings are under investigation. Anatomically, the ear is in close proximity to the mobile telephone during use. The effect of mobile phones on auditory function has rarely been studied. The aim of this review is to determine if there is evidence that mobile phones have a detrimental effect on auditory function.

aims: 1. compare memory ability between ct and mri radiographers using the rey auditory verbal learning test (ravlt) and between mri radiographers working with 1 and 1.5tesla (t) scanners. 2. investigate the change in memory ability (as measured by ravlt) with increasing time worked in mri.

subjects: 11 ct and mri radiographers from four hospital sites were included. each worked exclusively in their modality. ravlt was administered once to each subject. results show no significant difference between mri and ct groups' scores. there were significantly lower scores in subjects who worked more than 5 years in mri and subjects who worked with 1.5t scanners.

the results indicate that static magnetic fields may have a detrimental effect on memory ability. these results indicate the need for further research into the neuropsychological effects of the mri environment on occupationally exposed staff.