Magnetic shell enhancements during magnetic disturbances

Magnetic shell enhancements during magnetic field disturbances from Langmuir probe observations of electron density on Ariel I satellit

Towards Universal Pension Coverage in Mexico

In 2000 only 22% of older people in Mexico received a pension. Then, in 2002, the first non-contributory pension was introduced in Mexico City. Since then 17 of Mexico's 31 states have also introduced social pensions and so has the federal district. The introduction of these non-contributory pensions meant that in 2013 coverage had risen to 88%. This briefing first looks at the situation before social pensions were introduced, it then tracks the rise in coverage and finishes by suggesting some areas for improvement

Non-contributory Pensions: Bolivia and Antigua in an International Context

Includes bibliographyAbstract The author examines the pension systems of Bolivia and Antigua in the context of non-contributory pensions around the world, concluding with policy lessons. Universal pensions available to everyone of eligible age, regardless of income, assets or employment history, have many advantages over targeted pensions. If targeting is desired, it is best done with ex post recovery from other income rather than ex ante means tests. For reasons that are unclear, governments almost always prefer ex ante tests to ex post controls for noncontributory pensions, even though the reverse is true for tax collection. The worst type of old age pension, from the point of view of poverty relief, is a minimum pension tied to a contributory system or to government service, for this excludes the poorest and most vulnerable from benefits. Key words: Bolivia, Antigua and Barbuda, non-contributory pensions, social security, targeting, means tests

Molecular biology and genetics of epilepsy.

Genetic and molecular biological methodologies are being applied to the study of patients with epilepsy at an ever-increasing pace. Accurate classification of epilepsy within large families has allowed identification of genes through linkage analysis and then isolation of gene products. Mutations causing ion channel abnormalities coupled with clinical patterns of focal epilepsy syndromes are beginning to change our thinking about the etiology of recurrent seizures in all patients. Molecular methodology is beginning to have impact on understanding of the mechanisms of actions of drugs used to treat epilepsy and will have an impact on how future treatments are designed. </p

Natural antioxidants may prevent posttraumatic epilepsy: a proposal based on experimental animal studies.

Head injury or hemorrhagic cortical infarction results in extravasation of blood and breakdown of red blood cells and hemoglobin. Iron liberated from hemoglobin, and hemoglobin itself, are associated with the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS). ROS and RNS have been demonstrated to be involved in the mechanism of seizures induced by iron ions in the rat brain, an experimental animal model for posttraumatic epilepsy (PTE). ROS are responsible for the induction for peroxidation of neural lipids, i.e., an injury of neuronal membranes, and also could induce disorders in the excitatory and inhibitory neurotransmitters. Antioxidants, such as a phosphate diester of vitamin E and C (EPC-K1) and antiepileptic zonisamide, have been known to prevent the epileptogenic focus formation, or to attenuate seizure activities in the iron-injected rat brain. Natural antioxidants, such as alpha-tocopherol, and condensed tannins, including (-)-epigallocatechin and (-)-epigallocatechin-3-O-gallate, adenosine and its derivative, melatonin, uyaku (Lindera Strychnifolia), fermented papaya preparations, Gastrodia elata BI., and Guilingji, have been demonstrated to scavenge ROS and/or RNS and to be prophylactic for the occurrence of epileptic discharge in the iron-injected rat brain.</p

Holonomy groups and W-symmetries

Irreducible sigma models, i.e. those for which the partition function does not factorise, are defined on Riemannian spaces with irreducible holonomy groups. These special geometries are characterised by the existence of covariantly constant forms which in turn give rise to symmetries of the supersymmetric sigma model actions. The Poisson bracket algebra of the corresponding currents is a W-algebra. Extended supersymmetries arise as special cases.Comment: pages 2

Existence of immersed spheres minimizing curvature functionals in compact 3-manifolds

We study curvature functionals for immersed 2-spheres in a compact, three-dimensional Riemannian manifold M. Under the assumption that the sectional curvature of M is strictly positive, we prove the existence of a smoothly immersed sphere minimizing the L^{2} integral of the second fundamental form. Assuming instead that the sectional curvature is less than or equal to 2, and that there exists a point in M with scalar curvature bigger than 6, we obtain a smooth 2-sphere minimizing the integral of 1/4|H|^{2} +1, where H is the mean curvature vector