Collective epithelial migration drives kidney repair after acute injury.

Acute kidney injury (AKI) is a common and significant medical problem. Despite the kidney's remarkable regenerative capacity, the mortality rate for the AKI patients is high. Thus, there remains a need to better understand the cellular mechanisms of nephron repair in order to develop new strategies that would enhance the intrinsic ability of kidney tissue to regenerate. Here, using a novel, laser ablation-based, zebrafish model of AKI, we show that collective migration of kidney epithelial cells is a primary early response to acute injury. We also show that cell proliferation is a late response of regenerating kidney epithelia that follows cell migration during kidney repair. We propose a computational model that predicts this temporal relationship and suggests that cell stretch is a mechanical link between migration and proliferation, and present experimental evidence in support of this hypothesis. Overall, this study advances our understanding of kidney repair mechanisms by highlighting a primary role for collective cell migration, laying a foundation for new approaches to treatment of AKI.

A model for reducing health care employee turnover.

Explaining the rationale as to why employees leave their jobs has led to many different strategies to retain employees. The model presented here seeks to explain why employees choose to stay or to leave their place of employment. The information from the analysis will provide managers with well-tested tools to reduce turnover and to ascertain what employees value from their work environment in order to help the organization to retain those employees. The model identifies key factors that management can utilize to provide barriers to exit and retain professional employees in their health care units. Recommendations are provided that reward loyalty and build barriers to exit.