1,394 research outputs found
Compressed Exponential Relaxation as Superposition of Dual Structure in Pattern Dynamics of Nematic Liquid Crystals
Soft-mode turbulence (SMT) is the spatiotemporal chaos observed in
homeotropically aligned nematic liquid crystals, where non-thermal fluctuations
are induced by nonlinear coupling between the Nambu-Goldstone and convective
modes. The net and modal relaxations of the disorder pattern dynamics in SMT
have been studied to construct the statistical physics of nonlinear
nonequilibrium systems. The net relaxation dynamics is well-described by a
compressed exponential function and the modal one satisfies a dual structure,
dynamic crossover accompanied by a breaking of time-reversal invariance.
Because the net relaxation is described by a weighted mean of the modal ones
with respect to the wave number, the compressed-exponential behavior emerges as
a superposition of the dual structure. Here, we present experimental results of
the power spectra to discuss the compressed-exponential behavior and the dual
structure from a viewpoint of the harmonic analysis. We also derive a
relationship of the power spectra from the evolution equation of the modal
autocorrelation function. The formula will be helpful to study non-thermal
fluctuations in experiments such as the scattering methods.Comment: 17pages, 3 figures, to be published on AIP conference proceedings for
"The 4th International Symposium on Slow Dynamics in Complex Systems
Clostridium botulinum Type E Toxins Bind to Caco-2 Cells by a Different Mechanism from That of Type A Toxins
Cultured Clostridium botulinum strains produce progenitor toxins designated as 12S, 16S, and 19S toxins. The 12S toxin consists of a neurotoxin (NTX, 7S) and a non-toxic non-hemagglutinin (NTNH). The 16S and 19S toxins are formed by conjugation of the 12S toxin with hemagglutinin (HA), and the 19S toxin is a dimer of the 16S toxin. Type A cultures produce all 3 of these progenitor toxins, while type E produces only the 12S toxin. The 7S toxin is cleaved into heavy (H) and light (L) chains by a protease(s) in some strains, and the H chain has 2 domains, the N-terminus (Hn) and C-terminus (Hc). It has been reported that type A toxins bind to the intestinal cells or cultured cells via either HA or Hc. In this study, we investigated the binding of type A and E toxins to Caco-2 cells using Western blot analysis. Both the type E 7S and 12S toxins bound to the cells, with the 7S toxin binding more strongly, whereas, in the type A strain, only the 16S/19S toxins showed obvious binding. Pre-incubation of the type E 7S toxin with IgG against recombinant type E Hc significantly inhibited the 7S toxin binding, indicating that Hc might be a main binding domain of the type E toxin
Developmental changes in expression, subcellular distribution, and function of Drosophila N-cadherin, guided by a cell-intrinsic program during neuronal differentiation
Cell adhesion molecules (CAMs) perform numerous functions during neural development. An individual CAM can play different roles during each stage of neuronal differentiation; however, little is known about how such functional switching is accomplished. Here we show that Drosophila N-cadherin (CadN) is required at multiple developmental stages within the same neuronal population and that its sub-cellular expression pattern changes between the different stages. During development of mushroom body neurons and motoneurons, CadN is expressed at high levels on growing axons, whereas expression becomes downregulated and restricted to synaptic sites in mature neurons. Phenotypic analysis of CadN mutants reveals that developing axons require CadN for axon guidance and fasciculation, whereas mature neurons for terminal growth and receptor clustering. Furthermore, we demonstrate that CadN downregulation can be achieved in cultured neurons without synaptic contact with other cells. Neuronal silencing experiments using Kir_2.1 indicate that neuronal excitability is also dispensable for CadN downregulation in vivo. Interestingly, downregulation of CadN can be prematurely induced by ectopic expression of a nonselective cation channel, dTRPA1, in developing neurons. Together, we suggest that switching of CadN expression during neuronal differentiation involves regulated cation influx within neurons
NF-κB activator Act1 associates with IL-1/Toll pathway adaptor molecule TRAF6
AbstractNF-κB activator 1 (Act1), also called CIKS, is a recently identified protein with NF-κB and AP-1 activation activities through its association with the IκB kinase complex. We identified and confirmed that Act1 interacts with tumor necrosis factor receptor-associated factor 6 (TRAF6); notably, Act1 binds to TRAF6 only among TRAF family proteins. The amino-terminal half of Act1 is required for its interaction with the TRAF domain. Act1-mediated NF-κB activation was inhibited by a dominant-negative mutant of TRAF6 in a dose-dependent manner, and IL-1-induced NF-κB activation was inhibited by a high level of Act1 expression. Our results suggest that Act1 is involved in IL-1/Toll-mediated signaling through TRAF6
Lightning-Fast Dual-Layer Lossless Coding for Radiance Format High Dynamic Range Images
This paper proposes a fast dual-layer lossless coding for high dynamic range
images (HDRIs) in the Radiance format. The coding, which consists of a base
layer and a lossless enhancement layer, provides a standard dynamic range image
(SDRI) without requiring an additional algorithm at the decoder and can
losslessly decode the HDRI by adding the residual signals (residuals) between
the HDRI and SDRI to the SDRI, if desired. To suppress the dynamic range of the
residuals in the enhancement layer, the coding directly uses the mantissa and
exponent information from the Radiance format. To further reduce the residual
energy, each mantissa is modeled (estimated) as a linear function, i.e., a
simple linear regression, of the encoded-decoded SDRI in each region with the
same exponent. This is called simple linear regressive mantissa estimator.
Experimental results show that, compared with existing methods, our coding
reduces the average bitrate by approximately - % and significantly
reduces the average encoder implementation time by approximately
- %
Active Brownian Motion in Threshold Distribution of a Coulomb Blockade Model
Randomly-distributed offset charges affect the nonlinear current-voltage
property via the fluctuation of the threshold voltage of Coulomb blockade
arrays. We analytically derive the distribution of the threshold voltage for a
model of one-dimensional locally-coupled Coulomb blockade arrays, and propose a
general relationship between conductance and the distribution. In addition, we
show the distribution for a long array is equivalent to the distribution of the
number of upward steps for aligned objects of different height. The
distribution satisfies a novel Fokker-Planck equation corresponding to active
Brownian motion. The feature of the distribution is clarified by comparing it
with the Wigner and Ornstein-Uhlenbeck processes. It is not restricted to the
Coulomb blockade model, but instructive in statistical physics generally.Comment: 4pages, 3figure
<Abstract of published report>Formation of Novel Spirochlorin and Allylidenechlorin by the Reaction of Bromovinylporphyrin with Tetracyanoethylene.
<Abstract of published report>Dye-Sensitized Photooxidation of 2,4-Disubstituted Imidazoles : The Formation of Isomeric Imidazolinones.
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