Reliability and accuracy of single-molecule FRET studies for characterization of structural dynamics and distances in proteins

Single-molecule Förster-resonance energy transfer (smFRET) experiments allow the study of biomolecular structure and dynamics in vitro and in vivo. We performed an international blind study involving 19 laboratories to assess the uncertainty of FRET experiments for proteins with respect to the measured FRET efficiency histograms, determination of distances, and the detection and quantification of structural dynamics. Using two protein systems with distinct conformational changes and dynamics, we obtained an uncertainty of the FRET efficiency ≤0.06, corresponding to an interdye distance precision of ≤2 Å and accuracy of ≤5 Å. We further discuss the limits for detecting fluctuations in this distance range and how to identify dye perturbations. Our work demonstrates the ability of smFRET experiments to simultaneously measure distances and avoid the averaging of conformational dynamics for realistic protein systems, highlighting its importance in the expanding toolbox of integrative structural biology

Plan, Market and Regulatory Considerations in HMO Insolvency Prediction

Presents a study to derive a statistically based model to predict Health Maintenance Organization {HMO} insolvency. Focus on the HMO observable plan characteristics, HMO market area characteristics and state regulatory characteristics of a sample of insolvent and solvent HMOs; Estimation of each firm\u27s probability of insolvency using a logit model; Usefulness of the derived model to regulators

On the Relationship between HMO Board Composition and Financial Performance

This article focuses on how corporate governance influences the financial performance (as measured by the administrative expense ratio) of an HMO. Specifically, we examine the roles of physicians and plan administrators on the board of directors. These parties are assumed to behave as insiders because of their specialized knowledge. The empirical results indicate that administrative expenses for an HMO increase with an increasing proportion of physicians on the board, but tend to decrease as the proportion of administrators increases. While both groups are considered insiders, physicians and administrators seem to use the information they possess to different ends