105 research outputs found

    Equivariant R\mathbb R-test configurations of polarized spherical varieties

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    Let GG be a connected, complex reductive Lie group and G/HG/H a spherical homogenous space. Let (X,L)(X,L) be a polarized GG-variety which is a spherical embedding of G/HG/H. In this paper we classify GG-equivariant normal R\mathbb R-test configurations of (X,L)(X,L) via combinatory data. In particular we classify the special ones, and prove a finiteness theorem of central fibres of GG-equivariant special R\mathbb R-test configurations. Also, as an application we study the semistable degeneration problem of a Q\mathbb Q-Fano spherical variety.Comment: We added some Remarks 3.11, 5.5 and corrected some typo

    Weighted K-stability of Q\mathbb Q-Fano spherical varieties

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    Let GG be a connected, complex reductive Lie group and G/HG/H a spherical homogeneous space. Let XX be a Q\mathbb Q-Fano GG-spherical variety. In this paper we compute the weighed non-Archimedean functionals of a GG-equivariant normal test configurations of XX via combinatory data. Also we define a modified Futaki invariant with respect to the weight gg, and given an expression in terms of intersection numbers. Finally we show the equivalence of different notations of stability and gives a stability criterion on Q\mathbb Q-Fano spherical varieties, which is also a criterion of existence of K\"ahler-Ricci gg-solitons

    Nudel functions in membrane traffic mainly through association with Lis1 and cytoplasmic dynein

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    Nudel and Lis1 appear to regulate cytoplasmic dynein in neuronal migration and mitosis through direct interactions. However, whether or not they regulate other functions of dynein remains elusive. Herein, overexpression of a Nudel mutant defective in association with either Lis1 or dynein heavy chain is shown to cause dispersions of membranous organelles whose trafficking depends on dynein. In contrast, the wild-type Nudel and the double mutant that binds to neither protein are much less effective. Time-lapse microscopy for lysosomes reveals significant reduction in both frequencies and velocities of their minus end–directed motions in cells expressing the dynein-binding defective mutant, whereas neither the durations of movement nor the plus end–directed motility is considerably altered. Moreover, silencing Nudel expression by RNA interference results in Golgi apparatus fragmentation and cell death. Together, it is concluded that Nudel is critical for dynein motor activity in membrane transport and possibly other cellular activities through interactions with both Lis1 and dynein heavy chain

    Patients\u27 Acceptance of Smartphone Health Technology for Chronic Disease Management: A Theoretical Model and Empirical Test

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    Les quatre textes ont en commun de prĂ©senter certaines Ă©volutions rĂ©centes de l’histoire politique en Allemagne. Ils prennent tous position face Ă  trois tournants historiographiques. La notion d’histoire culturelle du politique peut servir d’emblĂšme au premier de ces tournants : le politique est envisagĂ© non plus comme une succession d’évĂ©nements ni comme le fruit de dĂ©terminations structurelles dont il serait la superstructure ou l’écume, mais comme l’expression de valeurs et de procĂ©dures o..

    Atypical radio pulsations from magnetar SGR 1935+2154

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    Magnetars are neutron stars with extremely strong magnetic fields, frequently powering high-energy activity in X-rays. Pulsed radio emission following some X-ray outbursts have been detected, albeit its physical origin is unclear. It has long been speculated that the origin of magnetars' radio signals is different from those from canonical pulsars, although convincing evidence is still lacking. Five months after magnetar SGR 1935+2154's X-ray outburst and its associated Fast Radio Burst (FRB) 20200428, a radio pulsar phase was discovered. Here we report the discovery of X-ray spectral hardening associated with the emergence of periodic radio pulsations from SGR 1935+2154 and a detailed analysis of the properties of the radio pulses. The complex radio pulse morphology, which contains both narrow-band emission and frequency drifts, has not been seen before in other magnetars, but is similar to those of repeating FRBs - even though the luminosities are many orders of magnitude different. The observations suggest that radio emission originates from the outer magnetosphere of the magnetar, and the surface heating due to the bombardment of inward-going particles from the radio emission region is responsible for the observed X-ray spectral hardening.Comment: 47 pages, 11 figure
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