Articular cartilage (AC), a biological tissue that protects and lubricates joints, plays a critical role during healthy locomotion. Ongoing work in the Cohen lab has been examining the spatially heterogeneous mechanical properties of this tissue using confocal rheology. This technique allows us to simultaneously deform the tissue with a known stress and measure the local strain field. From this information, we can calculate the local shear properties.
In thermal equilibrium, particles suspended in a fluid randomly move about due to kicks from the fluid molecules, in what is known as Brownian motion or diffusion. Shear a fluid, however, and the particles' diffusion will be greatly enhanced. Why? Diffusion spreads some of the particles to regions of the fluid with different velocities. As the fluid then carries different particles with different speeds, the particles spread out faster, effectively increasing the diffusion. This mechanism, dubbed Taylor dispersion after its discoverer G. I.
Recently, Itai Cohen caught up with Ellen Ferrante to discuss what it is like being a scientist. The interview is available on the LiveScience website, which has partnerships with MSNBC and Google News. ScienceLives is designed to showcase scientists and engineers who are
producing cutting-edge research in their fields.
In collaboration with the Cornell Center for Materials Research and the Ithaca Public Library, Jesse has been participating in the monthly series Families Learning Science Together. Themes range from "the science of bridge building" to "junk box experiments." Each month a new set of activities is available for children and parents to engage in together. Stop by the Ithaca library and ask about when the next event is scheduled, or email JLS533 <at> cornell.edu to find out more.
How do insects solve the problem of keeping stable in the face of unpredictable disturbances, such as gusts of wind? We devised a way to study insect flight control and stability by experimentally “tripping” insects in flight!