7,680 research outputs found
Axion Free-kick Misalignment Mechanism
We propose an alternative scenario for the axion misalignment mechanism based
on the nontrivial interplay between the axion and a light dilaton in the early
universe. Dark matter abundance is still sourced by the initial misalignment of
the axion field, whose motion along the potential kicks the dilaton field away
from its minimum, and dilaton starts to oscillate later with a delayed onset
time for oscillation and a relatively large misalignment value due to the kick;
eventually the dilaton dominates over the axion in their energy densities, and
the dilaton is identified as dark matter. The kick effect due to axion motion
is the most significant if the initial field value of dilaton is near its
minimum; therefore, we call this scenario axion free-kick misalignment
mechanism, where axion plays the role similar to a football player. Dark matter
abundance can be obtained with a lower axion decay constant compared to the
conventional misalignment mechanism.Comment: v2: 5+3 pages, 4 figures, references added, typo fixed, some
improvements, results unchange
Schwann cell transplantation and descending propriospinal regeneration after spinal cord injury
After spinal cord injury (SCI), poor ability of damaged axons of the central nervous system (CNS) to regenerate causes very limited functional recovery. Schwann cells (SCs) have been widely explored as promising donors for transplantation to promote axonal regeneration in the CNS including the spinal cord. Compared with other CNS axonal pathways, injured propriospinal tracts display the strongest regenerative response to SC transplantation. Even without providing additional neurotrophic factors, propriospinal axons can grow into the SC environment which is rarely seen in supraspinal tracts. Propriospinal tract has been found to respond to several important neurotrophic factors secreted by SCs. Therefore, the SC is considered to be one of the most promising candidates for cell-based therapies for SCI. Since many reviews have already appeared on topics of SC transplantation in SCI repair, this review will focus particularly on the rationale of SC transplantation in mediating descending propriospinal axonal regeneration as well as optimizing such regeneration by using different combinatorial strategies. This article is part of a Special Issue entitled SI: Spinal cord injury
Signature of Pseudo Nambu-Goldstone Higgs boson in its Decay
If the Higgs boson is a pseudo Nambu-Goldstone boson (PNGB), the
contact interaction induced by the invariants of the
non-linear sigma model is free from its nonlinearity effects. The process
can be used to eliminate the universal effects of heavy
particles, which can fake the nonlinearity effects of the PNGB Higgs boson in
the process (,\ ). We demonstrate that the
ratio of the signal strength of and
is good to distinguish the signature of the PNGB Higgs boson from Higgs
coupling deviations
The Influence of Augmented Reality Technology on the Learning Interest, Achievement of Learning Goals and Cognitive Load of Middle School Students
In order to test the influence of augmented reality technology on the learning interest achievement of learning goals and cognitive load the instruction of topographic map was taken as an example for experimental study This paper selected 427 students from 8 classes of Grade one who all come from Zhantan Middle School in Xindu District of Chengdu as experimental samples set two classes with similar level in learning as one group the one is the experimental class and the other is the control class and formed 4 groups in total The experimental classes adopted AR three-dimensional videos as teaching aids to give new lessons and the control classes adopted traditional two- dimensional videos and then the students learning interest level achievement of learning goals and cognitive load were measured The results showed that the application of AR technology in teaching could improve students learning interest and achievement of learning goals but had no effect on reducing cognitive loa
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