Organizing emergency preparedness within United States public health departments.

OBJECTIVES: We examined the manner in which state public health agencies have organized their operations to accomplish the goals associated with emergency preparedness (EP) funds. We also examined the leadership challenges associated with the effective utilization of preparedness funds. METHODS: The websites of all 50 state public health organizations in the USA were examined in order to determine the different approaches that states have used to organize for preparedness. Thirty-eight states provided sufficient information to allow for classification of their organizational approach to EP. Telephone interviews were conducted with representatives in three model states to obtain deeper insights into the organizational approach. RESULTS: Three predominant organizational models were identified as a means to address the challenge of organizing for preparedness. The results confirmed the equifinality principle of organization (there may be more than one equally effective way to organize) and demonstrated that, contrary to the prescription of early management thought, there is no 'one best way' to organize. Leadership rather than formal management emerged as the primary contributor to perceived EP. Specifically, interviews with preparedness professionals indicated that they believed expert power was more important than position power and the ability to negotiate and influence through persuasion was more important than formal authority. CONCLUSIONS: All three models contained, to a greater or lesser degree, elements of matrix management with the associated leadership challenges for emergency preparedness (EP) directors. Recommendations were provided for successful leadership in the context of EP directors in state departments of public health.

Capillary electrophoretic separation of uncharged polymers using polyelectrolyte engines. Theoretical model.

We recently demonstrated that the molecular mass distribution of an uncharged polymer sample can be analyzed using free-solution capillary electrophoresis of DNA-polymer conjugates. In these conjugates, the DNA is providing the electromotive force while the uncharged polydisperse polymer chains of the sample retard the DNA engine with different amounts of hydrodynamic drag. Here we present a theoretical model of this new analytical method. We show that for the most favourable, diffusion-limited electrophoresis conditions, there is actually an optimal DNA size to achieve the separation of a given polymer sample. Moreover, we demonstrate that the effective friction coefficient of the polymer chains is related to the stiffness of the two polymers of the conjugate, thus offering a method to estimate the persistence length of the uncharged polymer through mobility measurements. Finally, we compare some of our predictions with available experimental results.

Diffusion coefficient of DNA molecules during free solution electrophoresis.

The free-draining properties of DNA normally make it impossible to separate nucleic acids by free-flow electrophoresis. However, little is known, either theoretically or experimentally, about the diffusion coefficient of DNA molecules during free-flow electrophoresis. In fact, many authors simply assume that the Nernst-Einstein relation between the mobility and the diffusion coefficient still holds under such conditions. In this paper, we present an experimental study of the diffusion coefficient of both ssDNA and dsDNA molecules during free-flow electrophoresis. Our results unequivocally show that a simplistic use of Nernst-Einstein's relation fails, and that the electric field actually has no effect on the thermal diffusion process. Finally, we compare the dependence of the diffusion coefficient upon DNA molecular size to results obtained previously by other groups and to Zimm's theory.