Reversals in nature and the nature of reversals

The asymmetric shape of reversals of the Earth's magnetic field indicates a possible connection with relaxation oscillations as they were early discussed by van der Pol. A simple mean-field dynamo model with a spherically symmetric $\alpha$ coefficient is analysed with view on this similarity, and a comparison of the time series and the phase space trajectories with those of paleomagnetic measurements is carried out. For highly supercritical dynamos a very good agreement with the data is achieved. Deviations of numerical reversal sequences from Poisson statistics are analysed and compared with paleomagnetic data. The role of the inner core is discussed in a spectral theoretical context and arguments and numerical evidence is compiled that the growth of the inner core might be important for the long term changes of the reversal rate and the occurrence of superchrons.Comment: 24 pages, 12 figure

Osman Bey's "The Conquest of the World by Jews" (1873): a Liberal Antisemitism?

The chapter traces the profile of Osman Bey (aka Frederick Millingen, 1836-1905?) an Englishmen who converted from Protestantism to Catholicism to Islam, and finally to Christian Orthodoxy. He fought in the Ottoman and Russian Army and became a self-taught social scientist and journalist. He was the author, inter-alia, of a pamphlet on the supposed historical and contemporary role of Jews in world and economic affairs. This pamphlet, "The Conquest of the World by Jews" (1873) was one of the sources of the infamous forgery the "Protocols of the Elders of Zion" (1903)

Hyperkalemia in the Elderly: Drugs Exacerbate Impaired Potassium Homeostasis

OBJECTIVE: To review the pathophysiology underlying the predisposition to hyperkalemia in the elderly; the medications that disrupt potassium balance and promote the development of hyperkalemia in the elderly; the prevention of hyperkalemia in elderly patients treated with potassium-altering medications; and the appropriate management of hyperkalemia when it develops. METHODS AND MAIN RESULTS: A MEDLINE search of the literature (1966 –1996) using the terms hyperkalemia, drugs, elderly, and treatment was conducted and pertinent review articles, textbooks, and personal files were consulted. Elderly subjects appear to be predisposed to the development of hyperkalemia on the basis of both innate disturbances in potassium homeostasis and comorbid disease processes that impair potassium handling. Hyperkalemia in the elderly is most often precipitated by medications that impair cellular uptake or renal disposal of potassium. This electrolyte disorder is best prevented by recognition of at-risk physiology in the aged, avoidance of therapy with certain high-risk medications, and monitoring of plasma potassium concentration and renal function at intervals appropriate for the medication prescribed. Management of hyperkalemia entails identification of the clinical manifestations of severe hyperkalemia, stabilization of cardiac tissue, promotion of cellular potassium uptake, and ultimately removal of potassium from the body. CONCLUSIONS: Geriatric patients should be considered at risk of developing hyperkalemia, especially when they are prescribed certain medications. Potassium levels should be monitored at appropriate intervals when these patients are treated with potassium-altering medications. Appropriate management of hyperkalemia in the elderly can avoid life-threatening neuromuscular and cardiac complications