WilliamsRDM (United States)

Only one patch of snow survived on the hills of Scotland from the winter of 2018/2019 to the winter of 2019/2020.

Reports of autoregulation in the right coronary vasculature have varied from non-existent to almost perfect. At least some of this discrepancy may be due to failure to account for changes in myocardial metabolism secondary to the method used to vary perfusion pressure. The aim of this study was to determine if the potent autoregulation reported when right coronary perfusion pressure was lowered by opening a large arteriovenous shunt was due to increased right ventricular myocardial oxygen consumption (MVO2) induced by augmented preload and afterload. Two protocols were used to produce right coronary perfusion pressures of 100, 80, and 60 mm Hg in anaesthetised dogs. In both protocols the right coronary artery was cannulated and supplied with blood from a pressurised chamber. In protocol 1, right coronary perfusion pressure was decreased independently of aortic pressure, and in protocol 2, aortic pressure was decreased in parallel with right coronary perfusion pressure by opening a large arteriovenous shunt. Right coronary blood flow, central venous pressure, and pulmonary arterial pressure were measured, and right ventricular oxygen extraction and MVO2. Central venous pressure (right ventricular preload) and pulmonary arterial pressure (right ventricular afterload) did not change. In protocol 2, opening the arteriovenous shunt increased venous return, as shown by increased central venous pressure and pulmonary arterial pressure. This increased right ventricular MVO2 at the lower right coronary perfusion pressures and maintained right coronary blood flow at the level recorded when right coronary perfusion pressure was 100 mm Hg. This apparently potent autoregulation resulted from the shunt induced increase in oxygen consumption at low right coronary perfusion pressures, in contrast to the decreased right ventricular oxygen consumption and right coronary blood flow observed when right coronary perfusion pressure is selectively decreased.

The United States' energy crisis simmered throughout most of election year 1980 largely as a result of Saudi Arabia's maintenance of high production levels in the face of an oil glut on the world market and the IranIraq War. Congress created a Synthetic Fuels Corporation and a solar bank; but it unexpectedly killed the Energy Mobilization Board (EMB) in a House floor vote after the House and Senate had hammered out a compromise bill in conference.Thus, President Jimmy Carter's 1979 energy proposal which had worried students of federalism most went down to defeat while the federal government's role in energy development continued to expand generally. The apparent victory for federalism in the EMB defeat did not relieve the intense pressure on the federal system caused by America's thirst for energy. By the end of 1980, the signs of this pressure were apparent in a variety of contexts. In Congress one major 1980 proposal targets particular oil-burning plants for coal conversion, displacing state utility commission decisions of states primarily in the Northeast.2 The U.S. Department of Energy reported in 1980 that the state utility commissions were not implementing and apparently were resisting implementation of congressionally suggested rate reform measures for electrical power companies. Two federal district courts recently found that the 1954 Atomic Energy Act impliedly preempted what was previously thought to be state responsibility for nuclear plant siting and licensing matters.4 On a number