Nonlinear Terms of MHD Equations for Homogeneous Magnetized Shear Flow

We have derived the full set of MHD equations for incompressible shear flow of a magnetized fluid and considered their solution in the wave-vector space. The linearized equations give the famous amplification of slow magnetosonic waves and describe the magnetorotational instability. The nonlinear terms in our analysis are responsible for the creation of turbulence and self-sustained spectral density of the MHD (Alfven and pseudo-Alfven) waves. Perspectives for numerical simulations of weak turbulence and calculation of the effective viscosity of accretion disks are shortly discussed in k-space.Comment: 13 pages, no figures; AIP Conference Proceedings 1356, Proceedings of the School and Workshop on Space Plasma Physics (1--12 September 2010, Kiten, Bulgaria), American Institute of Physics, Melville, NY, 201

On BPS bounds in D=4 N=2 gauged supergravity II: general matter couplings and black hole masses

We continue the analysis of BPS bounds started in arXiv:1110.2688, extending it to the full class of N=2 gauged supergravity theories with arbitrary vector and hypermultiplets. We derive the general form of the asymptotic charges for asymptotically flat (M_4), anti-de Sitter (AdS_4), and magnetic anti-de Sitter (mAdS_4) spacetimes. Some particular examples from black hole physics are given to explicitly demonstrate how AdS and mAdS masses differ when solutions with non-trivial scalar profiles are considered.Comment: 21 pages; v2 added reference, published version; v3 minor correction

DIAGNOSTICAL VALUE OF LIQUOR CHANGES IN BRAIN STROKE PATIENTS

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Wake structure and kinematics in two insectivorous bats

We compare kinematics and wake structure over a range of flight speeds (4.0–8.2 m s(−1)) for two bats that pursue insect prey aerially, Tadarida brasiliensis and Myotis velifer. Body mass and wingspan are similar in these species, but M. velifer has broader wings and lower wing loading. By using high-speed videography and particle image velocimetry of steady flight in a wind tunnel, we show that three-dimensional kinematics and wake structure are similar in the two species at the higher speeds studied, but differ at lower speeds. At lower speeds, the two species show significant differences in mean angle of attack, body–wingtip distance and sweep angle. The distinct body vortex seen at low speed in T. brasiliensis and other bats studied to date is considerably weaker or absent in M. velifer. We suggest that this could be influenced by morphology: (i) the narrower thorax in this species probably reduces the body-induced discontinuity in circulation between the two wings and (ii) the wing loading is lower, hence the lift coefficient required for weight support is lower. As a result, in M. velifer, there may be a decreased disruption in the lift generation between the body and the wing, and the strength of the characteristic root vortex is greatly diminished, both suggesting increased flight efficiency. This article is part of the themed issue ‘Moving in a moving medium: new perspectives on flight’

Rotating BPS black holes in matter-coupled AdS(4) supergravity

Using the general recipe given in arXiv:0804.0009, where all timelike supersymmetric solutions of N=2, D=4 gauged supergravity coupled to abelian vector multiplets were classified, we construct genuine rotating supersymmetric black holes in AdS(4) with nonconstant scalar fields. This is done for the SU(1,1)/U(1) model with prepotential F=-iX^0X^1. In the static case, the black holes are uplifted to eleven dimensions, and generalize the solution found in hep-th/0105250 corresponding to membranes wrapping holomorphic curves in a Calabi-Yau five-fold. The constructed rotating black holes preserve one quarter of the supersymmetry, whereas their near-horizon geometry is one half BPS. Moreover, for constant scalars, we generalize (a supersymmetric subclass of) the Plebanski-Demianski solution of cosmological Einstein-Maxwell theory to an arbitrary number of vector multiplets. Remarkably, the latter turns out to be related to the dimensionally reduced gravitational Chern-Simons action.Comment: 23 pages, uses JHEP3.cl

Frequency of C > T polymorphism in fourth chromosome and levels of crp in patients with atrial

Introduction. Atrial fibrillation is a heart rhythm disorder, characterized by rapid and uncoordinated atrial activation which is the most common arrhythmia in clinical practice. Atrial fibrillation is observed in 1.5 - 2% of the general population and its incidence increases with age reaching more than 8-15% by 80 years of age. Atrial fibrillation is traditionally considered as a non genetic disorder. The cause of atrial fibrillation in 10-20% of cases is unknown and it is diagnosed as idiopathic

Non-supersymmetric Extremal RN-AdS Black Holes in N=2 Gauged Supergravity

We investigate extremal Reissner-Nordstrom-AdS black holes in four-dimensional N=2 abelian gauged supergravity. We find a new attractor equation which is not reduced to the one in the asymptotically flat spacetime. Focusing on so-called the T^3-model with a single neutral vector multiplet, we obtain non-supersymmetric extremal Reissner-Nordstrom-AdS black hole solutions with regular event horizon in the D0-D4 and the D2-D6 charge configurations. The negative cosmological constant emerges even without the Fayet-Iliopoulos parameters. Furthermore, we also argue the formal description of the non-supersymmetric black hole solutions of the T^3-model and the STU-model in generic configurations.Comment: 23 pages, accepted version in JHE