Quasilocal Energy for a Kerr black hole

The quasilocal energy associated with a constant stationary time slice of the Kerr spacetime is presented. The calculations are based on a recent proposal \cite{by} in which quasilocal energy is derived from the Hamiltonian of spatially bounded gravitational systems. Three different classes of boundary surfaces for the Kerr slice are considered (constant radius surfaces, round spheres, and the ergosurface). Their embeddings in both the Kerr slice and flat three-dimensional space (required as a normalization of the energy) are analyzed. The energy contained within each surface is explicitly calculated in the slow rotation regime and its properties discussed in detail. The energy is a positive, monotonically decreasing function of the boundary surface radius. It approaches the Arnowitt-Deser-Misner (ADM) mass at spatial infinity and reduces to (twice) the irreducible mass at the horizon of the Kerr black hole. The expressions possess the correct static limit and include negative contributions due to gravitational binding. The energy at the ergosurface is compared with the energies at other surfaces. Finally, the difficulties involved in an estimation of the energy in the fast rotation regime are discussed.Comment: 22 pages, Revtex, Alberta-Thy-18-94. (the approximations in Section IV have been improved. To appear in Phys. Rev. D

Viability Of Community Banks In The Dallas Federal Reserve District: Evidence Of Relationship And Transactional Orientation

This paper examines the viability of community banks. The results indicate that larger community banks are more profitable and less susceptible to most forms of risk than smaller community banks. Evidence that smaller community banks are more relationship oriented and larger community banks are more transactional oriented is mixed. Smaller community banks have a lower cost of funding assets, perhaps as a result of a stronger relationship with depositors, but there is no evidence that their relationship with borrowers allows them to earn more interest income. The primary indication of a stronger transactional orientation by larger community banks is their ability to generate more non-interest income

Enhancing the Sensitivity of SMS Fiber Sensors by the Use of High Refractive Index Coatings

This paper presents a study on the behavior of single-mode/multimode/single-mode sensors with diamond-like carbon coating of high refractive index. Spectra and response for different values of the external medium refractive index are recorded and analyzed

Derek Denny-brown: The Man Behind The Ganglia

The authors present an historical review about the main contributions of Professor Derek Denny-Brown to neurology. Some of his achievements include the first description of sensory neuronopathies, and some of the essential textbooks on the function and anatomy of the basal ganglia. In 2016, on the 35th anniversary of his death, modern neurologists are still strongly influenced by his legacy.75212712

An Adaptive Optics Survey of Stellar Variability at the Galactic Center

We present a $\approx 11.5$ year adaptive optics (AO) study of stellar variability and search for eclipsing binaries in the central $\sim 0.4$ pc ($\sim 10''$) of the Milky Way nuclear star cluster. We measure the photometry of 563 stars using the Keck II NIRC2 imager ($K'$-band, $\lambda_0 = 2.124 \text{ } \mu \text{m}$). We achieve a photometric uncertainty floor of $\Delta m_{K'} \sim 0.03$ ($\approx 3\%$), comparable to the highest precision achieved in other AO studies. Approximately half of our sample ($50 \pm 2 \%$) shows variability. $52 \pm 5\%$ of known early-type young stars and $43 \pm 4 \%$ of known late-type giants are variable. These variability fractions are higher than those of other young, massive star populations or late-type giants in globular clusters, and can be largely explained by two factors. First, our experiment time baseline is sensitive to long-term intrinsic stellar variability. Second, the proper motion of stars behind spatial inhomogeneities in the foreground extinction screen can lead to variability. We recover the two known Galactic center eclipsing binary systems: IRS 16SW and S4-258 (E60). We constrain the Galactic center eclipsing binary fraction of known early-type stars to be at least $2.4 \pm 1.7\%$. We find no evidence of an eclipsing binary among the young S-stars nor among the young stellar disk members. These results are consistent with the local OB eclipsing binary fraction. We identify a new periodic variable, S2-36, with a 39.43 day period. Further observations are necessary to determine the nature of this source.Comment: 69 pages, 28 figures, 12 tables. Accepted for publication in The Astrophysical Journa

Lowest Landau Level vortex structure of a Bose-Einstein condensate rotating in a harmonic plus quartic trap

We investigate the vortex patterns appearing in a two-dimensional annular Bose-Einstein condensate rotating in a quadratic plus quartic confining potential. We show that in the limit of small anharmonicity the Gross-Pitaevskii energy can be minimized amongst the Lowest Landau Level wave functions and use this particular form to get theoretical results in the spirit of [A. Aftalion X. Blanc F. Nier, Phys. Rev. A 73, 011601(R) (2006)]. In particular, we show that the vortex pattern is infinite but not uniform. We also compute numerically the complete vortex structure: it is an Abrikosov lattice strongly distorted near the edges of the condensate with multiply quantized vortices appearing at the center of the trap.Comment: 8 pages, 4 figure

Clinical Features And Management Of Hereditary Spastic Paraplegia.

Hereditary spastic paraplegia (HSP) is a group of genetically-determined disorders characterized by progressive spasticity and weakness of lower limbs. An apparently sporadic case of adult-onset spastic paraplegia is a frequent clinical problem and a significant proportion of cases are likely to be of genetic origin. HSP is clinically divided into pure and complicated forms. The later present with a wide range of additional neurological and systemic features. To date, there are up to 60 genetic subtypes described. All modes of monogenic inheritance have been described: autosomal dominant, autosomal recessive, X-linked and mitochondrial traits. Recent advances point to abnormal axonal transport as a key mechanism leading to the degeneration of the long motor neuron axons in the central nervous system in HSP. In this review we aim to address recent advances in the field, placing emphasis on key diagnostic features that will help practicing neurologists to identify and manage these conditions.72219-2

Activated carbon from polyurethane residues as molecular sieves for kinetic adsorption/separation of CO2/CH4

Activated carbon-based molecular sieves were synthetized, characterized and their kinetics of adsorption were evaluated to be used in separation processes of CO2/CH4 mixtures. Polyurethane (PU) foams were used as carbon precursors and the PU-derived carbons were physical activated with CO2. All the samples present a preferential adsorption of CO2 over methane in kinetic adsorption experiments. Samples activated at 800 ºC during 6 h exhibited the highest selectivity due to the absence of methane adsorption at lower resident times, which makes those samples very interesting for industrial processes of natural gas purification. Kinetic studies were performed to explain the kinetic profiles obtained, confirming that in the samples with smallest pore size, intraparticle diffusion was the limiting step, evidencing that certain oxygen groups favour CO2 adsorption, whereas adsorption was the limiting step in the samples with wider pores.This research was funded by MINECO (MAT2016-80285-p), GV (PROMETEOII/2014/004), H2020 (MSCA-RISE-2016/NanoMed Project). Financial support from the National Council for Scientific and Technological Development (CNPq-Brazil) is also acknowledged

Aspectos clínicos e manejo das paraplegias espásticas hereditárias

Hereditary spastic paraplegia (HSP) is a group of genetically-determined disorders characterized by progressive spasticity and weakness of lower limbs. An apparently sporadic case of adult-onset spastic paraplegia is a frequent clinical problem and a significant proportion of cases are likely to be of genetic origin. HSP is clinically divided into pure and complicated forms. The later present with a wide range of additional neurological and systemic features. To date, there are up to 60 genetic subtypes described. All modes of monogenic inheritance have been described: autosomal dominant, autosomal recessive, X-linked and mitochondrial traits. Recent advances point to abnormal axonal transport as a key mechanism leading to the degeneration of the long motor neuron axons in the central nervous system in HSP. In this review we aim to address recent advances in the field, placing emphasis on key diagnostic features that will help practicing neurologists to identify and manage these conditions.Paraplegias espásticas hereditárias (PEH) constituem um grupo de desordens geneticamente determinadas caracterizadas por espasticidade e paraparesia de progressão insidiosa. Paraplegia espástica aparentemente esporádica de início no adulto constitui problema frequente na prática neurológica. Evidências recentes sugerem que uma proporção significativa destes casos é geneticamente determinada. O grupo das PEH é dividido clinicamente em formas puras e complicadas de acordo com a concomitância de outras manifestações clinicas e neurológicas. Até o momento 60 tipos genéticos foram identificados. Todos os modos de herança monogênica já foram descritos: autossômica dominante, autossômica recessiva, ligada ao X e mitocondrial. Avanços recentes indicam que alterações do transporte axonal estão implicadas na degeneração dos longos axônios motores no sistema nervoso central na PEH. Nesta revisão abordamos recentes avanços na área com ênfase nos aspectos clínicos chave que ajudam o neurologista geral no diagnóstico e manejo correto deste grupo de doenças.21922