Blow-up results for a reaction-diffusion system

We consider the Cauchy problem for the reactiondiffusion ystem with the nonlinear terms |x|σjupj vqj . In this system, he exponents p1 and q2 play a crucial role to determine the ehavior of the solutions. Using an ODE method, we prove the ujita-type nonexistence results for p1, q2 1. Moreover, we also show the nonexistence results for arge initial data

GLOBAL EXISTENCE OF SOLUTIONS FOR A REACTION-DIFFUSION SYSTEM

We show the global existence of solutions of a reactiondiffusion system with the nonlinear terms |x|σjupj vqj . The proof is based on the existence of super-solutions and the comparison principle. We also prove that uniqueness of the global solutions holds in the superlinear case by contraction argument. Our conditions for the global existence are optimal in view of the nonexistence results proved by Yamauchi [12]

Two spatially distinct kinesin-14 proteins, Pkl1 and Klp2, generate collaborative inward forces against kinesin-5 Cut7 in S. pombe

Kinesin motors play central roles in bipolar spindle assembly. In many eukaryotes, spindle pole separation is driven by kinesin-5, which generates outward force. This outward force is balanced by antagonistic inward force elicited by kinesin-14 and/or dynein. In fission yeast, two kinesin-14 proteins, Pkl1 and Klp2, play an opposing role against the kinesin-5 motor protein Cut7. However, how the two kinesin-14 proteins coordinate individual activities remains elusive. Here, we show that although deletion of either pkl1 or klp2 rescues temperature-sensitive cut7 mutants, deletion of only pkl1 can bypass the lethality caused by cut7 deletion. Pkl1 is tethered to the spindle pole body, whereas Klp2 is localized along the spindle microtubule. Forced targeting of Klp2 to the spindle pole body, however, compensates for Pkl1 functions, indicating that cellular localizations, rather than individual motor specificities, differentiate between the two kinesin-14 proteins. Interestingly, human kinesin-14 (KIFC1 or HSET) can replace either Pkl1 or Klp2. Moreover, overproduction of HSET induces monopolar spindles, reminiscent of the phenotype of Cut7 inactivation. Taken together, this study has uncovered the biological mechanism whereby two different Kinesin- 14 motor proteins exert their antagonistic roles against kinesin-5 in a spatially distinct manner.This work was supported by the Japan Society for the Promotion of Science (JSPS) [KAKENHI Scientific Research (A) 16H02503 to T.T., a Challenging Exploratory Research grant 16K14672 to T.T., Scientific Research (C) 16K07694 to M.Y.], the Naito Foundation (T.T.) and the Uehara Memorial Foundation (T.T)

Axion Cloud Decay due to the Axion-photon Conversion with Multi-pole Background Magnetic Fields

We consider axion cloud decay due to the axion-photon conversion with multi-pole background magnetic fields. We focus on the $\ell=m=1$ and $n=2$ mode for the axion field configuration since it has the largest growth rate associated with superradiant instability. Under the existence of a background multi-pole magnetic field, the axion field can be converted into the electromagnetic field through the axion-photon coupling. Then the decay rate due to the dissipation of the converted photons is calculated in a successive approximation. We found that the decay rate is significantly dependent on the azimuthal quantum number characterizing the background magnetic field, and can be comparable to or larger than the growth rate of the superradiant instability.Comment: 13 pages, 1 figure. arXiv admin note: substantial text overlap with arXiv:2103.1322

Positions of Point-Nodes in Borocarbide Superconductor YNi2B2C

To determine the superconducting gap function of YNi2B2C, we calculate the local density of states (LDOS) around a single vortex core with the use of Eilenberger theory and the band structure calculated by local density approximation assuming various gap structures with point-nodes at different positions. We also calculate the angular-dependent heat capacity in the vortex state on the basis of the Doppler-Shift method. Comparing our results with the STM/STS experiment, the angular-dependent heat capacity and thermal conductivity, we propose the gap-structure of YNi2B2C, which has the point-nodes and gap minima along . Our gap-structure is consistent with all results of angular-resolved experiments.Comment: 7 pages, 5 figure