scholarly journals Pkd2 Affects Cilia Length and Impacts LR Flow Dynamics and Dand5

2021 ◽  
Vol 9 ◽  
Author(s):  
Raquel Jacinto ◽  
Pedro Sampaio ◽  
Mónica Roxo-Rosa ◽  
Sara Pestana ◽  
Susana S. Lopes
Keyword(s):  
Symmetry Breaking ◽  
Cell Shape ◽  
Flow Dynamics ◽  
Cell Stage ◽  
Permeable Channel ◽  
Putative Role ◽  
Breaking Mechanism

The left-right (LR) field recognizes the importance of the mechanism involving the calcium permeable channel Polycystin-2. However, whether the early LR symmetry breaking mechanism is exclusively via Polycystin-2 has not been tested. For that purpose, we need to be able to isolate the effects of decreasing the levels of Pkd2 protein from any eventual effects on flow dynamics. Here we demonstrate that curly-up (cup) homozygous mutants have abnormal flow dynamics. In addition, we performed one cell stage Pkd2 knockdowns and LR organizer specific Pkd2 knockdowns and observed that both techniques resulted in shorter cilia length and abnormal flow dynamics. We conclude that Pkd2 reduction leads to LR defects that cannot be assigned exclusively to its putative role in mediating mechanosensation because indirectly, by modifying cell shape or decreasing cilia length, Pkd2 deficit affects LR flow dynamics.

On the Dynamics of the Polygonal Satellite Vortices

2009 ◽  
Author(s):  
Hamid Ait Abderrahamane ◽  
Kamran Siddiqui ◽  
Georgios Vatistas
Keyword(s):  
Image Analysis ◽  
Symmetry Breaking ◽  
Vortex Core ◽  
Water Layer ◽  
Rotating Disk ◽  
Flow Dynamics ◽  
Cylindrical Container ◽  
Polygonal Pattern ◽  
Hollow Vortex ◽  
The Given

This paper deals with the dynamics of polygonal shapes resulting from the symmetry breaking of hollow-vortex core in a shallow water layer produced by a rotating disk near the bottom within a stationary cylindrical container. These polygonal shapes are investigated through image analysis. It is found that a given polygon rotates at the frequency close to one–third of the corresponding disk frequency and the flow dynamics around the apexes of the polygon is characterized by a frequency which is close to one–third of the frequency of the given polygonal pattern. The results also suggest a possible resonance between the satellite vortices at the apexes of the patterns and the bulk flow.

scholarly journals Spontaneous formation of geysers at only one pole on Enceladus’s ice shell

2020 ◽  
Vol 117 (26) ◽  
pp. 14764-14768 ◽  
Author(s):  
Wanying Kang ◽  
Glenn Flierl
Keyword(s):  
Symmetry Breaking ◽  
Shell Thickness ◽  
A Priori ◽  
Icy Moons ◽  
The North ◽  
Fracture Formation ◽  
Breaking Mechanism ◽  
The Mean ◽  
Ice Shell ◽  
North And South

The ice shell on Enceladus, an icy moon of Saturn, exhibits strong asymmetry between the northern and southern hemispheres, with all known geysers concentrated over the south pole, even though the expected pattern of tidal forced deformation should be symmetric between the north and south poles. Using an idealized ice-evolution model, we demonstrate that this asymmetry may form spontaneously, without any noticeable a priori asymmetry (such as a giant impact or a monopole structure of geological activity), in contrast to previous studies. Infinitesimal asymmetry in the ice shell thickness due to random perturbations are found to be able to grow indefinitely, ending up significantly thinning the ice shell at one of the poles, thereby allowing fracture formation there. Necessary conditions to trigger this hemispheric symmetry-breaking mechanism are found analytically. A rule of thumb we find is that, for Galilean and Saturnian icy moons, the ice shell can undergo hemispheric symmetry breaking only if the mean shell thickness is around 10 to 30 km.

Goldstone excitation and symmetry-breaking mechanism in superfluid-He4

1992 ◽  
Vol 14 (3) ◽  
pp. 229-238
Author(s):  
M. Ahmad ◽  
S. K. Tikoo ◽  
T. K. Raina
Keyword(s):  
Symmetry Breaking ◽  
Breaking Mechanism

SYMMETRY BREAKING BY WILSON LINES AND FINITE TEMPERATURE AND DENSITY EFFECTS

1993 ◽  
Vol 08 (16) ◽  
pp. 1495-1505 ◽  
Author(s):  
CHUNG-CHIEH LEE ◽  
CHOON-LIN HO
Keyword(s):  
Boundary Condition ◽  
Symmetry Breaking ◽  
Detailed Analysis ◽  
Gauge Group ◽  
Finite Temperature ◽  
Wilson Line ◽  
Adjoint Representation ◽  
Critical Temperatures ◽  
Massless Fermion ◽  
Breaking Mechanism

Effects of both finite temperature and density on Wilson line symmetry breaking mechanism is considered for an SU(N) theory defined on space-time manifold R1,d−2×S1 with massless fermion in the adjoint representation of the gauge group. Detailed analysis is given for the groups SU(2) and SU(3) on R1,2×S1. It is found that, at fixed fermion boundary condition, the critical temperatures and densities at which the full SU(N) symmetry is restored are the same for N=2 and N=3.

ON TIME VARIATION OF FUNDAMENTAL CONSTANTS IN SUPERSTRING THEORIES

1988 ◽  
Vol 03 (03) ◽  
pp. 243-249 ◽  
Author(s):  
KEI-ICHI MAEDA
Keyword(s):  
String Theory ◽  
Symmetry Breaking ◽  
Time Variation ◽  
Susy Breaking ◽  
Internal Space ◽  
Fundamental Constants ◽  
Breaking Mechanism ◽  
Dimensional Gravity ◽  
Superstring Theories ◽  
String Theories

Assuming the action from the string theory and taking into account the dynamical freedom of a dilaton and its coupling to matter fluid, we show that fundamental ‘constants’ in string theories are independent of the ‘radius’ of the internal space. Since the scalar related to the ‘constants’ is coupled to the 4-dimensional gravity and matter fluid in the same way as in the Jordan-Brans-Dicke theory with ω=−1, it must be massive and can get a mass easily through some symmetry breaking mechanism (e.g. the SUSY breaking due to a gluino condensation). Consequently, time variation of fundamental constants is too small to be observed.

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