Twist-joints and double twist-joints in RNA structure

Smectic Order in Double-Twist Cylinders

I propose a double-twist texture with local smectic order, which may have been seen in recent experiments [1]. As in the Renn-Lubensky TGB phase, the smectic order is broken only through a lattice of screw dislocations. A melted lattice of screw dislocations can produce a double-twist texture as can an unmelted lattice. In the latter case I show that geometry only allows for certain angles betw...

CoFold: thermodynamic RNA structure prediction with a kinetic twist

Existing state-of-the-art methods that take a single RNA sequence and predict the corresponding RNA ß are thermodynamic methods. These predict the most stable RNA structure, but do not consider the process of structure formation. We have by now ample experimental and theoretical evidence, however, that sequences in vivo fold while being transcribed and that the process of structure formation ma...

Interactions : Structure Functions , Higher Twist

Twist - 3 polarized structure functions ∗

We review the nucleon’s twist-3 polarized structure functions from the viewpoint of gauge invariant, nonlocal light-cone operators in QCD. We discuss a systematic treatment of the polarized structure functions and the corresponding parton distribution functions. We emphasize unique features of higher twist distributions, and the role of the QCD equations of motion to derive their anomalous dime...

Simulation of a New Process Design to Fabricate a Rectangular Twist Waveguide Using Extrusion and a Twist Die

The aim of the present study is to determine the feasibility of making a rectangular twist waveguide used to rotate electromagnetic waves. For this purpose, the process of fabricating an aluminum rectangular twist waveguide was simulated by making use of finite element method and Deform software. The optimum length and angle of the twist die for manufacturing a twist waveguide with inner cross ...