Near Horizon Extremal Geometry Perturbations: Dynamical Field Perturbations vs. Parametric Variations

In arXiv:1310.3727 we formulated and derived the three universal laws governing Near Horizon Extremal Geometries (NHEG). In this work we focus on the Entropy Perturbation Law (EPL) which, similarly to the first law of black hole thermodynamics, relates perturbations of the charges labeling perturbations around a given NHEG to the corresponding entropy perturbation. We show that field perturbations governed by the linearized equations of motion and symmetry conditions which we carefully specify, satisfy the EPL. We also show that these perturbations are limited to those coming from difference of two NHEG solutions (i.e. variations on the NHEG solution parameter space). Our analysis and discussions shed light on the "no-dynamics" statements of arXiv:0906.2380 and arXiv:0906.2376.Comment: 38 page

Extremal Rotating Black Holes in the Near-Horizon Limit: Phase Space and Symmetry Algebra

We construct the NHEG phase space, the classical phase space of Near-Horizon Extremal Geometries with fixed angular momenta and entropy, and with the largest symmetry algebra. We focus on vacuum solutions to $d$ dimensional Einstein gravity. Each element in the phase space is a geometry with $SL(2,\mathbb R)\times U(1)^{d-3}$ isometries which has vanishing $SL(2,\mathbb R)$ and constant $U(1)$ charges. We construct an on-shell vanishing symplectic structure, which leads to an infinite set of symplectic symmetries. In four spacetime dimensions, the phase space is unique and the symmetry algebra consists of the familiar Virasoro algebra, while in $d>4$ dimensions the symmetry algebra, the NHEG algebra, contains infinitely many Virasoro subalgebras. The nontrivial central term of the algebra is proportional to the black hole entropy. This phase space and in particular its symmetries might serve as a basis for a semiclassical description of extremal rotating black hole microstates.Comment: Published in PLB, 5 page

Wiggling Throat of Extremal Black Holes

We construct the classical phase space of geometries in the near-horizon region of vacuum extremal black holes as announced in [arXiv:1503.07861]. Motivated by the uniqueness theorems for such solutions and for perturbations around them, we build a family of metrics depending upon a single periodic function defined on the torus spanned by the $U(1)$ isometry directions. We show that this set of metrics is equipped with a consistent symplectic structure and hence defines a phase space. The phase space forms a representation of an infinite dimensional algebra of so-called symplectic symmetries. The symmetry algebra is an extension of the Virasoro algebra whose central extension is the black hole entropy. We motivate the choice of diffeomorphisms leading to the phase space and explicitly derive the symplectic structure, the algebra of symplectic symmetries and the corresponding conserved charges. We also discuss a formulation of these charges with a Liouville type stress-tensor on the torus defined by the $U(1)$ isometries and outline possible future directions.Comment: 56 pages, 3 figure

II in generalized supergravity

We showed in previous work that for homogeneous Yang-Baxter (YB) deformations of AdS$_5\times$S$^5$, the open string metric and coupling, and as a result the closed string density $e^{-2 \Phi} \sqrt{g}$, remain undeformed. In this work, in addition to extending these results to the deformation associated with the modified CYBE, or $\eta$-deformation, we identify the Page forms as the open string counterpart for RR fields and demonstrate case by case that the non-zero Page forms remain invariant under YB deformations. We give a physical meaning to the Killing vector $I$ of generalized supergravity and show for all YB deformations: 1) $I$ appears as a current for center of mass motion on the worldvolume of a D-branes probing the background, 2) $I$ is equal to the divergence of the noncommutativity parameter, 3) $I$ exhibits "holographic" behavior, where the radial component of $I$ vanishes at the AdS boundary, and 4) in pure spinor formalism $I$ is related to a certain state in the BRST cohomology.Comment: 11 pages, 2 column; v2 references updated; v3 to appear in EPJ

A capillary electrophoretic method for isolation and characterization of grape xylem proteins

European (Vitis vinifera) and American (Vitis labrusca) grape species succumb to a bacterial disease known as Pierce's Disease (PD). In contrast, muscadine grape genotypes (Vitis rotundifolia) are tolerant/resistant to PD. This is due to the unique biochemical composition of muscadine xylem. However, because of low protein concentration, conventional methods such as low-pressure chromatography and PAGE are unsuitable for grape xylem protein characterization. In addition, these procedures are tedious, time-consuming and require large amount of sample. This study reports a procedure for isolating and separating proteins from muscadine and bunch grape xylem tissue. The procedure consists of separation of xylem from cortex and phloem, removal of pigments and other gummy substances from xylem with ethanol: ethylacetate (2:1) and subsequent Capillary Electrophoretic (CE) analysis of xylem protein extracts to achieve desired resolution. Number of peaks, peak height and areas, retention time and baseline position were used to compare resolution and study the effect of sample and separation buffer. Xylem tissue proteins extracted with 0.05% sodium borate buffer (pH 8.3) and subjected to CE using 1.2% sodium borate (pH 8.3) as a separation buffer were found to yield most satisfactory resolution of grape xylem proteins. The data obtained by CE were consistent and reproducible, and hence, is well suited to obtain excellent resolution of xylem tissue protein for identifying differences in protein composition among the grape genotypes. (African Journal of Biotechnology: 2003 2(3): 66-70

A Study on Causes of Condemnation of Carcass and Organs at Shah Alam Abattoir

A two-week study of the causes of condemnation at Shah Alam abattoir was conducted. In the bovine species, liver and lungs w.ere the main organs condemned due to fluke infestation. and emphysema respectively. Ninety-five percent of pig lungs were condemned because of back bleeding, while in sheep caseous lymphadenitis was the major cause of organ condemnedtion affectingg mainly the lungs and lymph nodes. No total carcass condemnation was observed in any species during the study perio