9,561 research outputs found
Caspases in synaptic plasticity
Caspases are a family of cysteine proteases that play key roles in programmed cell death (apoptosis). Mounting evidence in recent years shows that caspases also have important non-apoptotic functions in multiple cellular processes, such as synaptic plasticity, dendritic development, learning and memory. In this article, we review the studies on the non-apoptotic functions of caspases in neurons, with a focus on their roles in synaptic plasticity, learning and memory and neurodegeneration
Detecting Majorana fermions by use of superconductor-quantum Hall liquid junctions
The point contact tunnel junctions between a one-dimensional topological
superconductor and single-channel quantum Hall (QH) liquids are investigated
theoretically with bosonization technology and renormalization group methods.
For the integer QH liquid, the universal low-energy tunneling transport
is governed by the perfect Andreev reflection fixed point with quantized
zero-bias conductance , which can serve as a definitive
fingerprint of the existence of a Majorana fermion. For the Laughlin
fractional QH liquids, its transport is governed by the perfect normal
reflection fixed point with vanishing zero-bias conductance and bias-dependent
conductance . Our setup is within reach of present
experimental techniques.Comment: 6 pages, 1 figure, Added references,Corrected typo
On the pinning strategy of complex networks
In pinning control of complex networks, a tacit believing is that the system
dynamics will be better controlled by pinning the large-degree nodes than the
small-degree ones. Here, by changing the number of pinned nodes, we find that,
when a significant fraction of the network nodes are pinned, pinning the
small-degree nodes could generally have a higher performance than pinning the
large-degree nodes. We demonstrate this interesting phenomenon on a variety of
complex networks, and analyze the underlying mechanisms by the model of star
networks. By changing the network properties, we also find that, comparing to
densely connected homogeneous networks, the advantage of the small-degree
pinning strategy is more distinct in sparsely connected heterogenous networks
Competing electronic orders on Kagome lattices at van Hove filling
The electronic orders in Hubbard models on a Kagome lattice at van Hove
filling are of intense current interest and debate. We study this issue using
the singular-mode functional renormalization group theory. We discover a rich
variety of electronic instabilities under short range interactions. With
increasing on-site repulsion , the system develops successively
ferromagnetism, intra unit-cell antiferromagnetism, and charge bond order. With
nearest-neighbor Coulomb interaction alone (U=0), the system develops
intra-unit-cell charge density wave order for small , s-wave
superconductivity for moderate , and the charge density wave order appears
again for even larger . With both and , we also find spin bond order
and chiral superconductivity in some particular
regimes of the phase diagram. We find that the s-wave superconductivity is a
result of charge density wave fluctuations and the squared logarithmic
divergence in the pairing susceptibility. On the other hand, the d-wave
superconductivity follows from bond order fluctuations that avoid the matrix
element effect. The phase diagram is vastly different from that in honeycomb
lattices because of the geometrical frustration in the Kagome lattice.Comment: 8 pages with 9 color figure
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