Actin filaments are semiflexible polymers that display large-scale conformational twisting and bending motions. Modulation of filament bending and twisting dynamics has been linked to regulatory actin-binding protein function, filament assembly and fragmentation, and overall cell motility. The relationship between actin filament bending and twisting dynamics has not been evaluated. The numerica...

A magnetic twisting stimulator was developed based on the previously published technique of magnetic twisting cytometry. Using ligand-coated ferromagnetic microbeads, this device can apply mechanical stresses with varying amplitudes, duration, frequencies, and waveforms to specific cell surface receptors. Biochemical and biological responses of the cells to the mechanical stimulation can be ass...

We calculate the structure of a force–free magnetosphere which is assumed to corotate with a central star and which interacts with an embedded differentially rotating accretion disc. The magnetic and rotation axes are aligned and the stellar field is assumed to be a dipole. We concentrate on the case when the amount of field line twisting through the disc–magnetosphere interaction is large and ...

Several factors regulate plant organ growth polarity. tortifolia2 (tor2), a right-handed helical growth mutant, has a conservative replacement of Arg-2 with Lys in the alpha-tubulin 4 protein. Based on a published high-resolution (2.89 A) tubulin structure, we predict that Arg-2 of alpha-tubulin forms hydrogen bonds with the GTPase domain of beta-tubulin, and structural modeling suggests that t...

the study of flight vehicle structures reveals the importance of obtaining the most suitable accuracy compatible with construction. for this purpose, several experiments were conducted at the agard institute. in this paper the results of one such experiment performed on a sample airplane wing are presented. aircraft structural engineers use several methods to model these structures. specifing h...

This study describes the initial phases of wing morphogenesis of Megoura viciae Buckton (Homoptera Aphididae). We evaluated the development of wing buds in males (winged) and parthenogenetic females (presumed to become wingless) of M. viciae from birth to 4 instar. Wing bud epithelium in males is initially simple, becoming bistratified and then progressing to stratify. Mitotic activity is more ...

A multi-objective optimization (MOO) of two-element wing models with morphing flap by using computational fluid dynamics (CFD) techniques, artificial neural networks (ANN), and non-dominated sorting genetic algorithms (NSGA II), is performed in this paper. At first, the domain is solved numerically in various two-element wing models with morphing flap using CFD techniques and lift (L) and drag ...

abstract: in this paper, optimization of boeing 747 wing has been accomplished for cruise condition (mach number=0.85, flight altitude=35000 ft), where an optimal wing shape is proposed. objective functions are minimization of wing weight and drag force that as well as confining design parameters, two functional constrains are applied. the first functional constrain is fuel tank volume in the a...