Techniques of Global analysis applied to gravitation theories: A cosmological black hole?

An elementary model of freely falling observers and emitters within a black hole's radius is examined to determine the redshift spectrum reaching a typical observer. The model is independent of scale, the fundamental unit being the radius (mass) of the black hole. The observers/emitters all follow the same kinds of trajectories: radially inward and starting from rest at spatial infinity. The test-particle role is assumed throughout; i.e., the observers/emitters do not themselves contribute to the gravitational field of the system. By means of redshift formulas and luminosity distance to the emitters, a picture of actual redshifts and blueshifts, with their intensities, emerges for an observer within the black hole's radius. No luminosity distances greater than approximately one-half the radius are considered in this particular study; nevertheless, redshifts and blueshifts up to approximately 0.6 are seen in portions of the observer's celestial sphere. An exotic application can be made, as a curiosity, to a black hole the size of the universe, resulting in a particular anisotropic "cosmology.

Remarks on the Myers-Perry and Einstein Gauss-Bonnet Rotating Solutions

The Kerr-type solutions of the five-dimensional Einstein and Einstein-Gauss-Bonnet equations look pretty similar when written in Kerr-Schild form. However the Myers-Perry spacetime is circular whereas the rotating solution of the Einstein-Gauss-Bonnet theory is not. We explore some consequences of this difference in particular regarding the (non) existence of Boyer-Lindquist-type coordinates and the extension of the manifold

The Goldberg-Sachs theorem in linearized gravity

The Goldberg-Sachs theorem has been very useful in constructing algebraically special exact solutions of Einstein vacuum equation. Most of the physical meaningful vacuum exact solutions are algebraically special. We show that the Goldberg-Sachs theorem is not true in linearized gravity. This is a remarkable result, which gives light on the understanding of the physical meaning of the linearized solutions.Comment: 6 pages, no figures, LaTeX 2

State Election Commission election guide

Prior to, during, and after a statewide election there are certain tasks that State Election Commission staff must complete to ensure that every county has a successful election. This guide attempts to address these tasks and to provide established institutional knowledge to current and new staff

Solution of the vacuum Kerr-Schild problem

The complete solution of the vacuum Kerr-Schild equations in general relativity is presented, including the space-times with a curved background metric. The corresponding result for a flat background has been obtained by Kerr.Comment: 8 page

The Ultrarelativistic Kerr-Geometry and its Energy-Momentum Tensor

The ultrarelativistic limit of the Schwarzschild and the Kerr-geometry together with their respective energy-momentum tensors is derived. The approach is based on tensor-distributions making use of the underlying Kerr-Schild structure, which remains stable under the ultrarelativistic boost.Comment: 16 pages, (AMS-LaTeX), TUW-94-0

George Morgan and Scott Poynting (eds) Global Islamophobia: Muslims and Moral Panic in the West. London: Ashgate.

Previous to 2001, Islam was a mere flicker on the radar of popular xenophobic paranoia. A decade and a half and the world’s first global moral panic later, this situation has changed entirely, apparently by design. As the editors of Global Islamophobia point out, the Terror Scare has elevated Muslims to ‘transnational folk devil,’ foisting the logic of ‘if you think for yourselves the terrorists win’ on the public realm in the name of defending democratic values. The paradoxical character of the generally destructive effects of this Terror Scare on democratic culture remains hard to miss, not least given the rhetoric about western values that tends to accompany much of the debate.Download the PDF file from this page to read Ben Debney's complete review of George Mirgan and Scott Poynting's edited book

Variation between European eel Anguilla anguilla (L.) stocks in five marshes of the Thames Estuary (United Kingdom)

The European eel (Anguilla anguilla, L.) was historically widely distributed throughout the United Kingdom, in coastal waters, lakes, rivers and wetlands. Recruitment has declined in recent decades and the species is now listed as ‘Critically Endangered’ on the International Union for Conservation of Nature and Natural Resources (IUCN) Red List. Management of suitable wetland habitats may contribute to species recovery; however, little is known about the stocks in these areas. In this study, yellow (adult stage > 300 mm) eels were sampled in ditches in five marshes bordering the Thames Estuary in England, UK. Ecological variables, including ditch characteristics, invertebrate abundance and water quality parameters were measured. Habitat features were also observed and recorded, including access, land use and water management regimes. Eels were found in all marshes, but at varying catch-per-unit-effort (CPUE). There were no significant correlations between CPUE and the ecological variables, except ditch width. However, a significant difference in CPUE was found between two of the marshes, which may be explained by variations in local habitat management. Mean lengths showed a high proportion of females and mean body condition of four of the marshes was also found to be greater than in three rivers in the same region. These findings suggest that the marshes are potentially favourable eel habitats and that factors influencing habitat quality, such as land use and water management, may affect eel abundance, production of females and body condition. Effective management of such wetlands may therefore contribute to the conservation of European eel

The role of glycogen and lactate in supporting action potential conduction in mouse central white matter and peripheral nerve

Central white matter and peripheral nerves function by conducting action potentials, which rely on the presence of transmembrane potentials generated by ion gradients. The maintenance of these transmembrane potentials is the main energy-dependent process in the nervous system. In this thesis I investigated the ability of endogenous glycogen to support the energy requirements of nervous tissue and the role of lactate in this process. Glycogen in the CNS is located in astrocytes but is capable of supporting axonal conduction, implying axon-glial metabolic interactions. These interactions were investigated in both the mouse optic nerve (MON), a central white matter tract, and the mouse sciatic nerve (MSN), a mixed peripheral nerve. Electrophysiological techniques were used to record action potential conduction in the nerves as an index of nerve function. Parallel experiments to quantify glycogen content using biochemical assay, or simultaneous real-time measurement of lactate release from the nerves using enzyme-based lactate biosensors, correlated action potential conduction with glycogen content, or lactate release, respectively. Depletion of glycogen leaves the MON vulnerable to irreversible injury to a greater extent than exposure to moderate hyperthermia during aglycemia. Glycogen also greatly enhanced the neuroprotective effects of mild hypothermia during aglycemia. Under resting conditions lactate in the immediate vicinity of the MON was stable at ~0.5 mM, a concentration that increased with axonal activity, dependent upon stimulus intensity. Raising extracellular K+ evoked lactate release, suggesting that increased neuronal activity promotes lactate release. Inhibition of glycogen metabolism, partly reduced lactate release from the MON, implying that glycogen metabolism is important under normal physiological conditions. The relative contribution of glycogen to lactate release increased with axonal activity, consistent with activity-induced glycogenolysis. These studies were then extended to the peripheral nervous system as the role of glycogen in this tissue has not previously been considered. Glycogen, which was present in Schwann cells, supported myelinated, but not un-myelinated axons during aglycemia, suggesting a more complex and selective neuroprotective role than that in central white matter. These results advance our understanding of white matter energy metabolism in relation to both the contributions of glycogen and lactate. The novel functional role of glycogen in supporting peripheral nerve function has also been described