scholarly journals Symmetry breaking in ideal magnetohydrodynamics: the role of the velocity

Author(s):  
Dimitri Cobb ◽  
Francesco Fanelli
2020 ◽  
Vol 48 (3) ◽  
pp. 1243-1253 ◽  
Author(s):  
Sukriti Kapoor ◽  
Sachin Kotak

Cellular asymmetries are vital for generating cell fate diversity during development and in stem cells. In the newly fertilized Caenorhabditis elegans embryo, centrosomes are responsible for polarity establishment, i.e. anterior–posterior body axis formation. The signal for polarity originates from the centrosomes and is transmitted to the cell cortex, where it disassembles the actomyosin network. This event leads to symmetry breaking and the establishment of distinct domains of evolutionarily conserved PAR proteins. However, the identity of an essential component that localizes to the centrosomes and promotes symmetry breaking was unknown. Recent work has uncovered that the loss of Aurora A kinase (AIR-1 in C. elegans and hereafter referred to as Aurora A) in the one-cell embryo disrupts stereotypical actomyosin-based cortical flows that occur at the time of polarity establishment. This misregulation of actomyosin flow dynamics results in the occurrence of two polarity axes. Notably, the role of Aurora A in ensuring a single polarity axis is independent of its well-established function in centrosome maturation. The mechanism by which Aurora A directs symmetry breaking is likely through direct regulation of Rho-dependent contractility. In this mini-review, we will discuss the unconventional role of Aurora A kinase in polarity establishment in C. elegans embryos and propose a refined model of centrosome-dependent symmetry breaking.


1997 ◽  
Vol 56 (20) ◽  
pp. 12947-12960 ◽  
Author(s):  
A. Zawadowski ◽  
G. Zaránd ◽  
P. Nozières ◽  
K. Vladár ◽  
G. T. Zimányi

2015 ◽  
Vol 51 (71) ◽  
pp. 13611-13614 ◽  
Author(s):  
Ananya Dutta ◽  
Jialiu Ma ◽  
Antek G. Wong-Foy ◽  
Adam J. Matzger

A coordination terpolymerization strategy is exploited to generate a non-interpenetrated pillared-layer coordination polymer with a non-regular layer arrangement. The role of breaking nodal symmetry is discussed.


2010 ◽  
Vol 25 (25) ◽  
pp. 4801-4826
Author(s):  
V. K. OIKONOMOU

In this paper, we study the influence of hard-supersymmetry-breaking terms in an N = 1, d = 4 supersymmetric model, with S1 × R3 space–time topology. It is found that for some interaction terms and for certain values of the couplings, supersymmetry is unbroken for small lengths of the compact radius and spontaneously breaks as the radius increases. Also, for another class of interaction terms, when the radius is large, supersymmetry is unbroken and spontaneously breaks as the radius decreases. It is pointed out that the two phenomena have similarities to the theory of metastable vacua at finite temperature, as well as to the inverse symmetry breaking of continuous symmetries at finite temperature (where the role of the temperature is played by the radius of the compact dimension).


2017 ◽  
Vol 25 (19) ◽  
pp. 22880 ◽  
Author(s):  
Álvaro Jiménez-Galán ◽  
Nickolai Zhavoronkov ◽  
Marcel Schloz ◽  
Felipe Morales ◽  
Misha Ivanov

Sign in / Sign up

Export Citation Format

Share Document