Directed Migration of cells is vital to a wide array of biological processes: from the coordinated migration of cells during embryo development to the uncontrollable migration of a metastatic cancer. We investigate directed cell migration in the model organism Dictyostelium aiming to understand the underlying biophysics of their motion, their direction, and the coordination among cell groups. The problem of
Two dimensional turbulence is an idealization of real 3D systems with anisotropy caused by geometric confinement or body forcing. I will review the current state of understanding of 2D turbulent flows including specific theoretical predictions, numerical simulation results and experimental realizations of quasi-2D turbulent systems. Relevance to geophysical systems will be discussed.
The discovery of neutrino oscillations has been one of the major advances in our understanding of particle physics in recent times, and we are still trying to fully understand them and the insights they may give to physics at very high energies and perhaps even into the matter-anti-matter asymmetry of the universe. Long Baseline Neutrino Oscillation Experiments are becoming one of the main tools for the study of neutrinos. The talk will briefly outline the history and physics of neutrino oscillations and long baseline experiments, and then discuss results from
In school, we learned that fluid flow becomes simple in two limits. Over long lengthscales and at high speeds, inertia dominates and the motion can approach that of a perfect fluid with zero viscosity. On short lengthscales and at slow speeds, viscous dissipation is important. Fluid flows that correspond to the formation of a finite-time singularity in the continuum description involve both a vanishing characteristic lengthscale and a diverging velocity scale. These flows can therefore evolve into final limits that defy expectations derived from properties o
Semiconductor nanowires synthesized in the bottom up approach have shown promising potential for a variety of applications in nanoelectronics, optoelectronics, biosensing and energy conversion. With the small length scale and a variety of material choices, nanowires also offer a versatile playground to explore mesoscopic and quantum physics. I will discuss our recent studies of magneto-transport phenomena in InAs and Bi2Se3 nanowires.
In the world of moderate Reynolds number, everyday turbulence of fluids flowing across planes and down pipes a velvet revolution is taking place. Experiments are almost as detailed as the numerical simulations, Numerical simulations are yielding exact numerical solutions that one dared not dream about a decade ago, and dynamical systems visualization of turbulent fluid's state space geometry is unexpectedly elegant.
Since the invention of the point contact transistor over 50 years ago, semiconductor technologies have become a ubiquitous mainstay of our Society. Continued advancements in these technologies rely heavily on materials research spanning many areas including polymer and organic materials which play significant roles as sacrificial, passive and active layers in electronic and photonic devices. The research outlined in this talk will identify fundamental materials parameters that will allow for the definition of materials architectures leading to sub-nanometer s
Fluid membranes (vesicles) are area-preserving interfaces that resist bending. They are models of cell membranes, intracellular organelles, and viral particles. We are interested in developing simulation tools for dilute suspensions of deformable vesicles. These tools should be computationally efficient, that is, they should scale well as the number of vesicles increases.