As long ago as 1968, V.S.Veselago (Sov.Phys.-Uspekhi, 10, pp. 509-514, 1968) showed that materials with EM parameters ε < 0 and μ < 0 have surprisingly different properties from the more familiar EM media. Only since 2000 or so have artificial materials been made with such 'double-negative' (DNG) properties. One interesting property is the ability of slabs of such material to act as lenses with respect to essentially monochromatic signals.

Most peculiar, and perhaps debatable, is a property claimed by J. Pendry (J.B. Pendry, Phys. Rev. Lett., 85, 3966-3969, 2000): 'perfect lensing' is possible because a monochromatic point source (which necessarily produces evanescent plane-wave components when incident upon a slab of properly-chosen DNG material) will be perfectly imaged at a point upon emerging on the other side, because the attenuation of the evanescent components is completely undone.

I will show that for any narrowband signal, even for transmission through very narrow slabs, such attenuation is not undone, even if it is for purely monochromatic waves.

My talk will include enough tutorial material to make it palatable to those who are less familiar with this or related topics.

The fate of chemical toxins that move through the natural and built environment is influenced significantly by the path the chemicals take. In many cases, toxins become diluted sufficiently so that they are not present in lethal concentrations, yet exposure to sub-lethal concentrations can still be deleterious to ecological and human health. My laboratory has focused primarily on understanding the impact of perturbations with chemical stressors on wastewater treatment plants, facilities comprising part of the built environment, by evaluating how molecular-scale phenomena induced by the stressors manifest into destructive macroscale phenomena. Specifically, we have hypothesized that physiological bacterial stress response mechanisms, which are activated at the molecular level, are responsible for macroscale-activated sludge process upsets caused by shock loads of toxic chemicals. We believe that distinct microbial stress fingerprints can be identified and correlated to different classes of chemicals, and that molecular-level stress responses are significant causal mechanisms that lead to significant process effect problems. As such, we have been working to understand the sourcecause-effect relationships for chemical toxins entering these waste treatment facilities. We are currently constructing a prototype microfluidic biosensor for application in the wastewater treatment industry for early detection of toxic shock loads based on outcomes from our sourcecause-effect studies. The basis behind the sensor concepts are all related to microbial stress responses. My presentation will provide a timeline of how we evaluated the impact of chemical stressors in this complex environment, and how recent mass spectrometric data has opened a new pathway toward solving the problem of detecting chemical perturbations in the built and natural environment. I will also explain how some of the bacterial stress responses we are studying are common between bacteria and humans, and I will propose that bacteria can serve as a robust model for detecting stress that is pertinent to a wide range of cellular types (including mammalian cells).

Laboratory experiments often do not meet the idealizations required by available theory making it difficult to compare experimental results with theoretical predictions. However, in many situations of engineering and scientific interest, it is now possible with efficient parallel programs and/or clever physically motivated numerical algorithms, to perform numerical simulations for precise experimental conditions allowing the link between theory and experiment to be made. We can gain new physical insights by exploiting numerical advantages, such as, for example: the ability to modify the physics in order to disentangle competing subtle effects, the capacity to measure quantities inaccessible to experiment, and the ability to investigate regimes beyond current experimental capabilities. In this talk this approach is used to gain new physical insight into the two physically diverse examples of spatiotemporal chaos in Rayleigh-Benard Convection and the stochastic Brownian motion of nanoscale cantilevers immersed in a viscous fluid for use in biofunctionalized nano-electro-mechanical-systems (BioNEMS) as a single molecule detector.

Atomic resolution structures for many proteins are now available by a variety of techniques. In solution, however, proteins adopt not one structure, but an ensemble of conformations. Computational studies of this ensemble remain beyond the reach of current computing resources, as many of the relevant fluctuations occur on millisecond timescales. I will present a new simulation protocol, called resolution exchange, which combines the detail of an all-atom model, with the sampling efficiency of a reduced resolution representation. Preliminary results will be presented for a pentapeptide neurotransmitter, met-enkephalin.

I want to present a brief overview about the analytical results on 2D percolation, especially within the last few years. After reviewing a novel algorithm for simulating percolation on the computer for very large systems with various boundary conditions and aspect ratios simultaneously, as well as "histogram methods" for percolation, I want to discuss the recent suggestion of the presence of "superscaling" in 2D percolation.