Perturbations in the Kerr-Newman Dilatonic Black Hole Background: I. Maxwell waves

In this paper we analyze the perturbations of the Kerr-Newman dilatonic black hole background. For this purpose we perform a double expansion in both the background electric charge and the wave parameters of the relevant quantities in the Newman-Penrose formalism. We then display the gravitational, dilatonic and electromagnetic equations, which reproduce the static solution (at zero order in the wave parameter) and the corresponding wave equations in the Kerr background (at first order in the wave parameter and zero order in the electric charge). At higher orders in the electric charge one encounters corrections to the propagations of waves induced by the presence of a non-vanishing dilaton. An explicit computation is carried out for the electromagnetic waves up to the asymptotic form of the Maxwell field perturbations produced by the interaction with dilatonic waves. A simple physical model is proposed which could make these perturbations relevant to the detection of radiation coming from the region of space near a black hole.Comment: RevTeX, 36 pages in preprint style, 1 figure posted as a separate PS file, submitted to Phys. Rev.

Comparison of three collection techniques for capture of Coleoptera, with an emphasis on saproxylic species, in Great Smoky Mountains National Park, USA

Collection methods and/or habitats sampled influence how many and which species are captured during entomological surveys. Here we compare Coleoptera catches among three survey activities, each using a single collection method, at the same study sites in Great Smoky Mountains National Park, USA. Activities included: short-term flight intercept trapping (FITs); sifting/Berlese funneling of leaf litter and extremely decayed downed coarse woody debris; and using emergence chambers containing coarse woody debris of various decay classes. In total, 2472 adult beetle specimens, representing 217 lowest identifiable taxa within 164 genera and 42 families, were collected during the FIT survey. Each survey activity yielded more than 2000 specimens, and a combined total of 413 species was collected. A combination of all surveys yielded the highest species richness when normalized for number of specimens indicating that variation of habitat and/or collection method significantly increases species richness. Of single surveys the FIT survey had the highest absolute species richness (217) and the highest richness when normalized for number of specimens. Species overlap among survey activities was low (Sorensen’s quotient of similarity was 0.20–0.27), which showed that each was about equally dissimilar from all others. Overlap of catch between FITs and emergence chambers was too low to justify substitution of emergence surveys with the FIT survey protocol used when attempting to collect saproxylic Coleoptera

Microfield Dynamics of Black Holes

The microcanonical treatment of black holes as opposed to the canonical formulation is reviewed and some major differences are displayed. In particular the decay rates are compared in the two different pictures.Comment: 22 pages, 4 figures, Revtex, Minor change in forma

Structure-function relationships underlying GluA2 mechanisms of deactivation, desensitization, and modulation

2013 Spring.Includes bibliographical references.Glutamate is the primary excitatory neurotransmitter in the central nervous system, where it is principally responsible for mediating excitatory neurotransmission. Ligand-gated receptors to glutamate, such as the a-amino-3-hydroxy-5-methyl-isoxazole-propionic acid (AMPA) receptor, are responsible for many cognitive processes; with the AMPA receptor showing an essential role in learning, memory, and synaptic plasticity. As many mental illnesses and diseases show underlying cognitive complications, therapeutic drugs that can alleviate these cognitive deficits show tremendous potential benefit. However, despite great interest and continued advancement, progress of drugs through clinical trials into available treatments has been slow and problematic. One potential reason for the slow progress of drug development is a lack of basic understanding for how compounds bind to AMPA receptors and upregulate their function. Presented here are several studies aimed to better understand how structural interactions regulate AMPA receptor mechanisms of gating and modulation. These studies combine fast-perfusion electrophysiology capable of simulating synaptic events with structural information obtained from x-ray crystallography studies to analyze potential mechanisms of allosteric modulation. Promisingly, we have identified potential patterns relating modulator properties such as size and rigidity with their observed physiological effects. Such patterns suggest that information from these studies can facilitate design of more targeted and efficacious cognition enhancing drugs. In addition to this drug analysis, we identify a new potential drug target site: the AMPA receptor outer vestibule near the ion-conducting pore. We further characterize that alteration to this site acts independently of other modulators, providing a site for modulators that may accompany current pharmacological therapies. Together, these studies demonstrate that structural information can be successfully applied to the process of drug design, with the added benefit of enhancing our understanding for molecular mechanisms of AMPA receptor function

Destined or Doomed? Hungarian Dissidents and Their Western Friends, 1973-1998

Through the lens of Hungarian dissidents and their supporters in the West, the following study analyzes the motivations of intellectuals from East and West to engage in an open East-West dialogue, their efforts to change the social and political structure of the Cold War, and their contributions to the peaceful revolutions of 1989. It investigates the alliance of intellectuals from either side of the Iron Curtain, their formative experiences and mutual influences. To understand the origins, functions, and legacy of this network, the study investigates the period from the 1960s to the late 1990s, focusing on the years 1973 to 1998. Findings suggest that the motivations that would bring intellectuals from either side of the Iron Curtain together in the 1980s originated in similarly formative experiences in the 1960s, which shattered their youthful convictions and initiated a search for a new intellectual identity that would bring Easterners and Westerners together by the late 1970s. In response to the encounter, the participants developed a distinct set of political and historical convictions that rooted in cultural liberalism, their commitment to free, open and democratic societies, and the acceptance of universal human rights. This case study touches upon developments throughout Eastern Europe and evaluates the history of the Cold War as interplay between East and West. It indicates a retreat from authoritarian rule in the East as early as 1987, and highlights the problematic, one-sided perception of the Hungarian Democratic Opposition in the West. It discusses the achievements of the former dissidents, and their struggle to adjust to the situation in post-1989 Europe. The project is based on archival research in six different countries; findings are based on documents found in private collections, national libraries, institutional, national and state security archives. Additionally, over forty eyewitnesses and experts shared their experiences and views in interviews conducted between 2009 and 2012

Polynyas in a dynamic-thermodynamic sea-ice model

The representation of polynyas in viscous-plastic dynamic-thermodynamic sea-ice models is studied in a simplified test domain, in order to give recommendations about parametrisation choices. Bjornsson et al. (2001) validated their dynamic-thermodynamic model against a polynya flux model in a similar setup and we expand on that work here, testing more sea-ice rheologies and new-ice thickness formulations. The two additional rheologies tested give nearly identical results whereas the two new-ice thickness parametrisations tested give widely different results. Based on our results we argue for using the new-ice thickness parametrisation of Hibler (1979). We also implement a new parametrisation for the parameter <i>h</i><sup>0</sup> from Hibler's scheme, based on ideas from a collection depth parametrisation for flux polynya models

Noncommutative Quantum Hall Effect and Aharonov-Bohm Effect

We study a system of electrons moving on a noncommutative plane in the presence of an external magnetic field which is perpendicular to this plane. For generality we assume that the coordinates and the momenta are both noncommutative. We make a transformation from the noncommutative coordinates to a set of commuting coordinates and then we write the Hamiltonian for this system. The energy spectrum and the expectation value of the current can then be calculated and the Hall conductivity can be extracted. We use the same method to calculate the phase shift for the Aharonov-Bohm effect. Precession measurements could allow strong upper limits to be imposed on the noncommutativity coordinate and momentum parameters $\Theta$ and $\Xi$.Comment: 9 pages, RevTeX4, references added, small changes in the tex

The biogeography of sodium in Neotropical figs (Moraceae)

© 2016 The Association for Tropical Biology and Conservation Sodium is essential for animals but not for most plants. Terrestrial sodium comes largely from marine aerosols, so inland ecosystems should have greater potential for sodium limitation than coastal ecosystems. We report a significant decrease of sodium in fruits of four Neotropical Ficus species with distance from presumed marine source