Modeling heterogeneities in the crosslinked bacterial sacculus

On the architecture of the gram-negative bacterial murein sacculus.

The peptidoglycan network of the murein sacculus must be porous so that nutrients, waste products, and secreted proteins can pass through. Using Escherichia coli and Pseudomonas aeruginosa as a baseline for gram-negative sacculi, the hole size distribution in the peptidoglycan network has been modeled by computer simulation to deduce the network's properties. By requiring that the distribution ...

Heterogeneities in the glassy state.

We study heterogeneities in a binary Lennard-Jones system below the glass transition using molecular dynamics simulations. We identify mobile and immobile particles and measure their distribution of vibrational amplitudes. For temperatures near the glass transition the distribution of vibrational amplitudes obeys scaling and compares reasonably well with a mean-field theory for the amorphous so...

Modeling mechanophore activation within a crosslinked glassy matrix

Analysis of the microphonic potential of the bullfrog's sacculus.

The sensory epithelium from the bullfrog's sacculus was mounted between two chambers and stimulated by moving the otolithic membrane with a piezoelectric stimulator. The evoked response was measured as the transepithelial "microphonic" potential or, when the epithelium was voltage clamped, as the microphonic current. Microphonic responses were similar to those recorded in other preparations: th...

Heterogeneities in granular dynamics.

The absence of Brownian motion in granular media is a source of much complexity, including the prevalence of heterogeneity, whether static or dynamic, within a given system. Such strong heterogeneities can exist as a function of depth in a box of grains; this is the system we study here. First, we present results from three-dimensional, cooperative and stochastic Monte Carlo shaking simulations...