Non-linear stress-softening of the bacterial cell wall confers cell shape homeostasis.

The bacillus - or rod - is a pervasive cellular morphology among bacteria. Rod-shaped cells elongate without widening by reinforcing their cell wall anisotropically to prevent turgor pressure from inflating cell width. Here, we demonstrate that a constrictive force is also essential for avoiding pressure-driven widening in Gram-positive bacteria.

Modeling the impact of single-cell stochasticity and size control on the population growth rate in asymmetrically dividing cells.

Microbial populations show striking diversity in cell growth morphology and lifecycle; however, our understanding of how these factors influence the growth rate of cell populations remains limited. We use theory and simulations to predict the impact of asymmetric cell division, cell size regulation and single-cell stochasticity on the population growth rate. Our model predicts that coarse-grained noise in the single-cell growth rate λ decreases the population growth rate, as previously seen for symmetrically dividing cells.

Cell-size regulation in budding yeast does not depend on linear accumulation of Whi5.

Cells must couple cell-cycle progress to their growth rate to restrict the spread of cell sizes present throughout a population. Linear, rather than exponential, accumulation of Whi5, was proposed to provide this coordination by causing a higher Whi5 concentration in cells born at a smaller size. We tested this model using the inducible promoter to make the Whi5 concentration independent of cell size.

Details Matter: Noise and Model Structure Set the Relationship between Cell Size and Cell Cycle Timing.

Organisms across all domains of life regulate the size of their cells. However, the means by which this is done is poorly understood. We study two abstracted "molecular" models for size regulation: inhibitor dilution and initiator accumulation.

The surprising economics of a "people business".

When people are your most important asset, some standard performance measures and management practices become misleading or irrelevant. This is a danger for any business whose people costs are greater than its capital costs-that is, businesses in most industries. But it is particularly true for what the authors call "people businesses": operations with high employee costs, low capital investment, and limited spending on activities, such as R&D, that are aimed at generating future revenue.