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Molecular mechanisms that stabilize short term synaptic plasticity during presynaptic homeostatic plasticity.
Presynaptic homeostatic plasticity (PHP) compensates for impaired postsynaptic neurotransmitter receptor function through a rapid, persistent adjustment of neurotransmitter release, an effect that can exceed 200%. An unexplained property of PHP is the preservation of short-term plasticity (STP), thereby stabilizing activity-dependent synaptic information transfer. We demonstrate that the dramatic potentiation of presynaptic release during PHP is achieved while simultaneously maintaining a constant ratio of primed to super-primed synaptic vesicles, thereby preserving STP. Mechanistically, genetic, biochemical and electrophysiological evidence argue that a constant ratio of primed to super-primed synaptic vesicles is achieved by the concerted action of three proteins: Unc18, Syntaxin1A and RIM. Our data support a model based on the regulated availability of Unc18 at the presynaptic active zone, a process that is restrained by Syntaxin1A and facilitated by RIM. As such, regulated vesicle priming/super-priming enables PHP to stabilize both synaptic gain and the activity-dependent transfer of information at a synapse
Self-dual solutions of Yang-Mills theory on Euclidean AdS space
We find non-trivial, time-dependent solutions of the (anti) self-dual
Yang-Mills equations in the four dimensional Euclidean Anti-de Sitter space. In
contrast to the Euclidean flat space, the action depends on the moduli
parameters and the charge can take any non-integer value.Comment: 11 pages, 2 figures; version 2: new references added, to appear in
PR
Comment on the new AdS universe
We show that Bonnor's new Anti-de Sitter (AdS) universe and its D-dimensional
generalization is the previously studied AdS soliton.Comment: 2 pages; version 2: major changes including the titl
A Novel Partially Biobased PAN-Lignin Blend as a Potential Carbon Fiber Precursor
Blends of polyacrylonitrile (PAN) and lignin were prepared with three different lignin types by solution blending and solution casting. Among three types of lignin, one type was chosen and different blend concentrations were prepared and casted. The casted blend films were characterized chemically with fourier transform infrared spectroscopy (FTIR), and thermally with thermogravimetric analysis (TGA). The mechanical properties of the blends were measured using dynamic mechanical analysis (DMA). FTIR analysis shows an excellent interaction of PAN and lignin. The interaction of the lignins and PAN was confirmed by TGA analysis. The DMA results reveal that the lignin enhance the mechanical properties of PAN at room temperature and elevated temperatures. The blend structure and morphology were observed using scanning electron microscopy (SEM). SEM images show that excellent polymer blends were prepared. The results show that it is possible to develop a new precursor material with a blend of lignin and PAN. These studies show that the side product of paper and cellulosic bioethanol industries, namely, lignin can be used for new application areas
Cylindrically Symmetric Vacuum Solutions in Higher Dimensional Brans-Dicke Theory
Higher dimensional, static, cylindrically symmetric vacuum solutions with and
without a cosmological constant in the Brans-Dicke theory are presented. We
show that, for a negative cosmological constant and for specific values of the
parameters, a particular subclass of these solutions include higher dimensional
topological black hole-type solutions with a flat horizon topology. We briefly
extend our discussion to stationary vacuum and vacuum solutions.Comment: V3: Published Versio
Superradiance of a Global Monopole in Reissner-Nordstr\"{o}m(-AdS) Space-time
In this article, the behaviour of a charged and massive scalar field around a
global monopole swallowed by a Reissner-Nordstr\"{o}m-Anti-de Sitter (RN-AdS)
black hole is investigated by considering the Klein-Gordon equation in this
geometry. The superradiance phenomenon and instability behaviour of the black
hole against charged scalar perturbations are studied for both an RN-AdS case
and also for an RN black hole surrounded by a reflective mirror, i.e., the
black hole bomb case. The effects of the monopole on these cases are discussed
analytically and also with the help of several graphs in detail. The monopole
charge affects the superradiance threshold frequency and also effects the
instability time scale for both cases. The existence of global monopole makes
these black holes more stable against superradiance instability.Comment: V3: 19 pages, 3 figures, references added, introduction is extended,
Revtex, Published versio
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