Reassessment of pre-industrial fire emissions strongly affects anthropogenic aerosol forcing

Uncertainty in pre-industrial natural aerosol emissions is a major component of the overall uncertainty in the radiative forcing of climate. Improved characterisation of natural emissions and their radiative effects can therefore increase the accuracy of global climate model projections. Here we show that revised assumptions about pre-industrial fire activity result in significantly increased aerosol concentrations in the pre-industrial atmosphere. Revised global model simulations predict a 35% reduction in the calculated global mean cloud albedo forcing over the Industrial Era (1750–2000 CE) compared to estimates using emissions data from the Sixth Coupled Model Intercomparison Project. An estimated upper limit to pre-industrial fire emissions results in a much greater (91%) reduction in forcing. When compared to 26 other uncertain parameters or inputs in our model, pre-industrial fire emissions are by far the single largest source of uncertainty in pre-industrial aerosol concentrations, and hence in our understanding of the magnitude of the historical radiative forcing due to anthropogenic aerosol emissions

Superconducting RF Enabling technology for modern light sources

Superconducting radio frequency SRF technology holds the promise of low beam impedance, high gradient, CW operation and thus is ideally suited for use in high power synchrotron light sources. Over 30 years of research and development has helped to bring the technology to maturity and to the point that its near turn key operation is now feasible in such facilities. Many SRF systems are in routine operation in both storage ring and LINAC based light sources and are the key to the realization of a number of novel light source concepts such as ERLs, compact sources, x ray oscillator FELs, or short pulse operation in storage rings. An overview of the principles and advantages of SRF as well as the technology s state of the art and future challenges is give

PREAMI: Perindopril and remodelling in elderly with acute myocardial infarction: Study rationale and design

Angiotensin-converting enzyme (ACE) inhibitors reduce mortality, the development of remodeling, left ventricular (LV) dysfunction, and ischemic events, both when administered alone as long-term treatment in patients with impaired LV function and/or heart failure (HF) and as short-term treatment, early after acute myocardial infarction (AMI) and/or HF. The few data available on the use of ACE inhibitors in the elderly after AMI are conflicting. Nothing is known about the effects of ACE inhibitors in elderly postinfarction patients with preserved LV function: these patients have a remarkable medium- to long-term mortality and HF incidence after infarction. The aim of this study is to evaluate, in patients with AMI aged ≥65 years, the effects of Perindopril on the combined outcome of death, hospitalization for HF, and heart remodeling, considered to be a ≥8% increase in LV end-diastolic volume (LVEDV). Secondary objectives include the same factors listed in the primary end points hut considered separately. In addition, safety of the drug, ventricular remodeling, and adaptation are being evaluated. A total of 1100 patients with AMI (first episode or reinfarction), aged ≥65 years, and preserved or only moderately depressed LV (LV ejection fraction ≥40%), are to he enrolled and randomly assigned to treatment (8 mg for 12 months of Perindopril or placebo, in double-blind conditions). Clinical assessment is performed at fixed times, and periodic evaluations of (1) ventricular shape, dimensions, and function by quantitative 2-D echocardiography, and (2) heart rate variability and arrhythmias by ambulatory electrocardiographic monitoring are anticipated. The results and conclusions will be available by 2002 year