4pi Models of CMEs and ICMEs

Coronal mass ejections (CMEs), which dynamically connect the solar surface to the far reaches of interplanetary space, represent a major anifestation of solar activity. They are not only of principal interest but also play a pivotal role in the context of space weather predictions. The steady improvement of both numerical methods and computational resources during recent years has allowed for the creation of increasingly realistic models of interplanetary CMEs (ICMEs), which can now be compared to high-quality observational data from various space-bound missions. This review discusses existing models of CMEs, characterizing them by scientific aim and scope, CME initiation method, and physical effects included, thereby stressing the importance of fully 3-D ('4pi') spatial coverage.Comment: 14 pages plus references. Comments welcome. Accepted for publication in Solar Physics (SUN-360 topical issue

The Origin, Early Evolution and Predictability of Solar Eruptions

Coronal mass ejections (CMEs) were discovered in the early 1970s when space-borne coronagraphs revealed that eruptions of plasma are ejected from the Sun. Today, it is known that the Sun produces eruptive flares, filament eruptions, coronal mass ejections and failed eruptions; all thought to be due to a release of energy stored in the coronal magnetic field during its drastic reconfiguration. This review discusses the observations and physical mechanisms behind this eruptive activity, with a view to making an assessment of the current capability of forecasting these events for space weather risk and impact mitigation. Whilst a wealth of observations exist, and detailed models have been developed, there still exists a need to draw these approaches together. In particular more realistic models are encouraged in order to asses the full range of complexity of the solar atmosphere and the criteria for which an eruption is formed. From the observational side, a more detailed understanding of the role of photospheric flows and reconnection is needed in order to identify the evolutionary path that ultimately means a magnetic structure will erupt

Digitalis for treatment of congestive heart failure in patients in sinus rhythm

Background: Digitalis glycosides have been in clinical use in the treatment of congestive heart failure for more than 200 years. In recent years several trials have been conducted to address concerns about efficacy and toxicity. Although a systematic review of the literature was recently published, an update is required to include more current trials. Objectives: To examine the effectiveness of digitalis glycosides in treating congestive heart failure in patients with normal sinus rhythm. To examine the effect of digitalis in patients taking diuretics, angiotensin converting enzyme (ACE) inhibitors, and beta blockers; patients with varying severity and duration of disease; patients with prior exposure to digitalis vs. no prior exposure; and patients with diastolic vs. systolic dysfunction. Search strategy: Electronic databases were searched between 1966 and 2000. Dissertation Abstracts and annual meeting abstracts of the American Heart Association, American College of Cardiology, and European Society of Cardiology were searched from 1996-2000. In addition, reference lists provided by the pharmaceutical industry (Glaxo Wellcome Inc.) were searched. Selection criteria: Included were randomized placebo-controlled trials of 20 or more adult patients of either sex with symptomatic congestive heart failure who were studied for seven weeks or more. Excluded were trials in which the prevalence of atrial fibrillation was 2% or greater, or in which any arrhythmia that might compromise cardiac function or any potentially reversible cause of heart failure such as acute ischemic heart disease or myocarditis was present. Data collection and analysis Articles selected from the searches described above were reviewed by one of the coauthors, and validated by staff from the central office of the Heart Collaborative Review Group in Bristol, UK. Main results: Eleven articles meeting the defined criteria were identified, and major endpoints of mortality, hospitalization, and clinical status, based respectively upon 8, 4, and 10 of these selected studies, were recorded and analyzed. The data show that there is no evidence of a difference in mortality between treatment and control groups, whereas digitalis therapy is associated with a lower rate of hospitalization and of clinical deterioration. Reviewer's conclusions The literature indicates that digitalis has a useful role in the treatment of patients with congestive heart failure who are in normal sinus rhythm

Understanding the dynamics of electoral reform

After a long period of stasis 1993 marked a burst of change in liberal democracies' electoral arrangements. There were major shifts in three established democratic countries (Italy, Japan, and New Zealand), and a new system in Russia. All four changes show some parallels as well as some distinct features, especially in adopting "mixed" electoral systems. The roots of this pattern lie deep in the multiple criteria involved in debates about voting systems. Multi-dimensionality also explains some of the inherent difficulties of implementing reform, which we consider in the context of the revived electoral reform debate in the UK. Lastly, we examine the pressures for "convergence" in electoral systems at work in plurality rule countries, where party systems show tendencies to fragment; and in proportional representation systems, where public demands for greater accountability have emerged