In 2012, a U.S. Institute of Medicine report called for a different approach to health care: “Left unchanged, health care will continue to underperform; cause unnecessary harm; and strain national, state, and family budgets.” The answer, they suggested, would be a “continuously learning” health system. Ethicists and researchers urged the creation of “learning health organizations” that would integrate knowledge from patient‐care data to continuously improve the quality of care. Our experience with an ongoing research study on atrial fibrillation—a trial known (...) as IMPACT‐AFib—gave us some insight into one of the challenges that will have to be dealt with in creating these organizations. Although the proposed educational intervention study placed no restrictions on what providers and health plans could do, the oversight team argued that the ethical principle of beneficence did not allow the researchers to be “bystanders” in relation to a control group receiving suboptimal care. In response, the researchers designed a “workaround” that allowed the project to go forward. We believe the experience suggests that what we call “bystander ethics” will create challenges for the kinds of quality improvement research that LHOs are designed to do. (shrink)

In 2012, a U.S. Institute of Medicine report called for a different approach to health care: “Left unchanged, health care will continue to underperform; cause unnecessary harm; and strain national, state, and family budgets.” The answer, they suggested, would be a “continuously learning” health system. Ethicists and researchers urged the creation of “learning health organizations” that would integrate knowledge from patient‐care data to continuously improve the quality of care. Our experience with an ongoing research study on atrial fibrillation—a trial known (...) as IMPACT‐AFib—gave us some insight into one of the challenges that will have to be dealt with in creating these organizations. Although the proposed educational intervention study placed no restrictions on what providers and health plans could do, the oversight team argued that the ethical principle of beneficence did not allow the researchers to be “bystanders” in relation to a control group receiving suboptimal care. In response, the researchers designed a “workaround” that allowed the project to go forward. We believe the experience suggests that what we call “bystander ethics” will create challenges for the kinds of quality improvement research that LHOs are designed to do. (shrink)

When fcc single crystals with high-symmetry crystal orientations are deformed to moderate strains by rolling, tension or channel die compression, long dislocation boundaries inclined to the extension axis form. Similarly, long dislocation boundaries are often found in grains embedded in polycrystals deformed in the same manner. These extended planar boundaries are characteristically - 30-40° from the extension direction and contain the transverse specimen axis. The objective of the present article is to demonstrate that EPBs formed during plane strain deformation (...) are parallel to equivalent slip planes, a pair of hypothetical slip systems used for analyses of the strain and crystal rotation components in place of the larger number of physical slip systems. The coincidence of EPBs and equivalent slip plane inclinations is shown to account for persistent observations of EPBs in the angle range - 30-40° from the rolling direction, in rolled single crystals of various initial orientations. The tendency of EPBs towards tilt or twist boundary character can also be rationalized on the basis of the equivalent slip system concept and consideration of the dislocation types available to be incorporated into EPBs. (shrink)

The evolution of microstructure upon partial crystallization and its influence on the mechanical properties such as hardness, elastic modulus and viscosity in a La 55 Al 25 Cu 10 Ni 5 Co 5 bulk metallic glass alloy are studied. Specimens with various volume fractions of crystalline phases were obtained by annealing the as-cast amorphous alloy above its glass transition temperature and were characterized by transmission electron microscopy. Microscopic examination of the heat-treated samples shows short-range-ordered domains prior to nanocrystallization within the (...) amorphous matrix, followed by the growth and impingement of the crystallites. Whereas the hardness of the annealed samples increases linearly with increasing crystallinity, the elastic modulus and the viscosity both increase abruptly when the crystalline volume fraction is about 40 vol.%, with a only minor variation on either side of this range. The sudden rises in the modulus and viscosity are similar to those in the literature data on the fracture strength of partially crystallized bulk amorphous alloys that shows a steep drop in strength at 30-50 vol.% crystallinity. On the basis of the microscopic observations, it is suggested that the interaction and formation of rigid networks of crystalline phases upon the attainment of a critical second-phase volume fraction may be the possible reason for the sudden change in mechanical properties. Percolation theory is utilized in further substantiating this hypothesis. (shrink)