375 research outputs found
GABA(A) receptor phospho-dependent modulation is regulated by phospholipase C-related inactive protein type 1, a novel protein phosphatase 1 anchoring protein
GABA(A) receptors are critical in controlling neuronal activity. Here, we examined the role for phospholipase C-related inactive protein type 1 (PRIP-1), which binds and inactivates protein phosphatase 1alpha (PP1alpha) in facilitating GABA(A) receptor phospho-dependent regulation using PRIP-1(-/-) mice. In wild-type animals, robust phosphorylation and functional modulation of GABA(A) receptors containing beta3 subunits by cAMP-dependent protein kinase was evident, which was diminished in PRIP-1(-/-) mice. PRIP-1(-/-) mice exhibited enhanced PP1alpha activity compared with controls. Furthermore, PRIP-1 was able to interact directly with GABA(A) receptor beta subunits, and moreover, these proteins were found to be PP1alpha substrates. Finally, phosphorylation of PRIP-1 on threonine 94 facilitated the dissociation of PP1alpha-PRIP-1 complexes, providing a local mechanism for the activation of PP1alpha. Together, these results suggest an essential role for PRIP-1 in controlling GABA(A) receptor activity via regulating subunit phosphorylation and thereby the efficacy of neuronal inhibition mediated by these receptors
Interacting SUSY-singlet matter in non-relativistic Chern-Simons theory
We construct an example of supersymmetric Chern-Simons-matter theory with a
matter field transforming as a singlet representation of the supersymmetry
algebra, where the bosonic and fermionic degrees of freedom do not match. This
is obtained as a non-relativistic limit of the N=2 Chern-Simons-matter theory
in 1+2 dimensions, where the particle and anti-particle coexist. We also study
the index to investigate the mimatch of bosonic and fermionic degrees of
freedom.Comment: 11page
Holographic Renormalization of Foliation Preserving Gravity and Trace Anomaly
From the holographic renormalizationg group viewpoint, while the scale
transformation plays a primary role in the duality by providing the extra
dimension, the special conformal transformation seems to only play a secondary
role. We, however, claim that the space-time diffeomorphism is crucially
related to the latter. For its demonstration, we study the holographic
renormalization group flow of a foliation preserving diffeomophic theory of
gravity (a.k.a. space-time flipped Horava gravity). We find that the dual field
theory, if any, is only scale invariant but not conformal invariant. In
particular, we show that the holographic trace anomaly in four-dimension
predicts the Ricci scalar squared term that would be incompatible with the
Wess-Zumino consistency condition if it were conformal. This illustrates how
the foliation preserving diffeomophic theory of gravity could be inconsistent
with a theorem of the dual unitary quantum field theory.Comment: 18 pages, v2: reference added, v3: comments on more recent literature
added in response to referee's reques
A family of super Schrodinger invariant Chern-Simons matter systems
We investigate non-relativistic limits of the N=3 Chern-Simons matter system
in 1+2 dimensions. The relativistic theory can generate several inequivalent
super Schodinger invariant theories, depending on the degrees of freedom we
choose to retain in the non-relativistic limit. The maximally supersymmetric
Schrodinger invariant theory is obtained by keeping all particle degrees of
freedom. The other descendants, where particles and anti-particles coexist, are
also Schrodinger invariant but preserve less supersymmetries. Thus, we have a
family of super Schrodinger invariant field theories produced from the parent
relativistic theory.Comment: 1+35 pages, references added and typos fixe
QUASI-SPHERICAL, TIME-DEPENDENT VISCOUS ACCRETION FLOW: ONE-DIMENSIONAL RESULTS
We investigated the instability of advective accretion flow as a consequence of angular momentum transfer in one-dimensional, quasi-spherical transonic accretion flow around a non-rotating black hole. The code is designed to include the effects of viscosity; the hydrodynamics component preserves angular momentum strictly with Lagrangian and remap method in the absence of viscosity, while the viscosity component updates viscous angular momentum transfer through the implicit method. We performed two tests to demonstrate the suitability of the code for accretion study. First, we simulated the inviscid, low angular momentum, transonic accretion flow with shocks around a black hole, and then the subsonic, self-similarADAF solution around a Newtonian object. Both simulations fitted the corresponding analytical curves extremely well. We then simulated a rotating, viscous, transonic fluid with shocks. We showed that for low viscosity parameter, stable shocks at larger distance are possible. For higher viscosity parameter, more efficient angular momentum transfer in the post-shock disk makes the shock structure oscillatory. Moreover, as the shock drifts to larger distances, a secondary inner shock develops. We showed that the inner shock is the direct consequence of the expansion of the outer shock, as well as the creation of regions with partial derivative l/partial derivative r < 0 due to more efficient angular momentum transfer near the inner sonic point. We showed that all disk parameters, including emissivity, oscillate with the same period as that of the shock oscillation. Our simulation may have implications for low frequency quasi-periodic oscillations, e.g., GRO J1655-40 and XTE J1550-564open8
Hysteresis effects and diagnostics of the shock formation in low angular momentum axisymmetric accretion in the Kerr metric
The secular evolution of the purely general relativistic low angular momentum
accretion flow around a spinning black hole is shown to exhibit hysteresis
effects. This confirms that a stationary shock is an integral part of such an
accretion disc in the Kerr metric. The equations describing the space gradient
of the dynamical flow velocity of the accreting matter have been shown to be
equivalent to a first order autonomous dynamical systems. Fixed point analysis
ensures that such flow must be multi-transonic for certain astrophysically
relevant initial boundary conditions. Contrary to the existing consensus in the
literature, the critical points and the sonic points are proved not to be
isomorphic in general. Homoclinic orbits for the flow flow possessing multiple
critical points select the critical point with the higher entropy accretion
rate, confirming that the entropy accretion rate is the degeneracy removing
agent in the system. However, heteroclinic orbits are also observed for some
special situation, where both the saddle type critical points of the flow
configuration possesses identical entropy accretion rate. Topologies with
heteroclinic orbits are thus the only allowed non removable degenerate
solutions for accretion flow with multiple critical points, and are shown to be
structurally unstable. Depending on suitable initial boundary conditions, a
homoclinic trajectory can be combined with a standard non homoclinic orbit
through an energy preserving Rankine-Hugoniot type of stationary shock. An
effective Lyapunov index has been proposed to analytically confirm why certain
class of transonic flow can not accommodate shock solutions even if it produces
multiple critical points. (Abridged)Comment: mn2e.cls format. 24 pages. 4 figure
Growth of n-type γ-CuCl with improved carrier concentration by pulsed dc sputtering: structural, electronic and UV emission properties
Copper (I) chloride is naturally a direct band gap, zincblende and p-type semiconductor material with much potential in linear and non-linear optical applications owing to its large free excitonic binding energy. In order to fabricate an efficient electrically pumped emitter, a combination of both p-type and n-type semiconductor materials will be required. In this study, we report on the growth of n-type γ-CuCl with improved carrier concentration by pulsed dc magnetron sputtering of CuCl/Zn target. An improvement of carrier concentration up to an order of ~ 9.8x1018 cm-3, which is much higher than the previously reported (~ 1016 cm-3), has been achieved. An enhancement in crystallinity of CuCl along the (111) orientation and its consistency with the morphological studies have also been investigated as an effect of doping. Influence of Zn wt % in the sputtering target on the Hall mobility and resistivity of the doped films is explored. The strong ultraviolet emission of doped films is confirmed using room temperature and low temperature photoluminescence studies
Boundary and defect CFT: Open problems and applications
A review of Boundary and defect conformal field theory: open problems and applications, following a workshop held at Chicheley Hall, Buckinghamshire, UK, 7–8 Sept. 2017. We attempt to provide a broad, bird’s-eye view of the latest progress in boundary and defect conformal field theory in various sub-fields of theoretical physics, including the renormalization group, integrability, conformal bootstrap, topological field theory, supersymmetry, holographic duality, and more. We also discuss open questions and promising research directions in each of these sub-fields, and combinations thereof
Spin Hall magnetoresistance and spin Nernst magnetothermopower in a Rashba system: role of the inverse spin galvanic effect
In ferromagnet/normal-metal bilayers, the sensitivity of the spin Hall
magnetoresistance and the spin Nernst magnetothermopower to the boundary
conditions at the interface is of central importance. In general, such boundary
conditions can be substantially affected by current-induced spin polarizations.
In order to quantify the role of the latter, we consider a Rashba
two-dimensional electron gas with a ferromagnet attached to one side of the
system. The geometry of such a system maximizes the effect of current-induced
spin polarization on the boundary conditions, and the spin Hall
magnetoresistance is shown to acquire a non-trivial and asymmetric dependence
on the magnetization direction of the ferromagnet.Comment: 20 pages, 7 figure
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