Circadian (~24 hour) clocks are endogenous mechanisms that time the recurring, daily activities observed in most organisms. These clocks are genetically regulated, and generate biochemical oscillations within individual cells composing most tissues. Recently our laboratory has searched for and identified genes that affect the homeostatic regulation of sleep in Drosophila. This research has uncovered specific neurons whose activity promotes sleep.
Integral equation methods play an important role in the numerical simulation of electromagnetic scattering. They are easy to employ in complex geometry and impose the desired radiation conditions at infinity without the need for artificial numerical boundaries. Two of the obstacles faced by current forward simulation tools are “low-frequency breakdown” and the lack of easy […]
In biological systems, there are striking examples where complicated structures (i.e., the bacterial ribosome) can spontaneously assemble, driven by specific interactions between the components. But how can systems be designed to have this property? Recent technological advances have created the opportunity for making technologically relevant systems that self assemble, using strands of DNA or objects coated with DNA. We will use these systems as inspiration to formulate theoretical models to understand how self assembly works in these systems, through theory, numerical simulation and experiment — and start to speculate as to whether resulting principles might be useful for unravelling the rules of biological self-assembly.
Thought experiments have played an important role in figuring out the laws of physics. For the unification of quantum mechanics and gravity, where the phenomena take place in extreme regimes, they are even more crucial. Hawking’s 1976 paper “Breakdown of Predictability in Gravitational Collapse” presented one of the great thought experiments in the history of physics, arguing that black holes destroy information in a way that requires a modification of the laws of quantum mechanics. Skeptics for years failed to
poke holes in Hawking’s argument, but concluded that if quantum mechanics is to be saved then our understanding of spacetime must break down in a radical way.
In this talk, Mike Shelley discusses problems in fluid-structure interaction ranging from the macroscopic, i.e. flapping of flags and bending of tree leaves, to the micro – collective behaviors of micro-organisms and the transport of subcellular structures.