We present results from a large suite of simulations of Saturn’s dense A and B rings using a new model of particle sticking in local simulations (Perrine, R.P., Richardson, D.C., Scheeres, D.J. [2011]. Icarus 212, 719– 735). In this model, colliding particles can be incorporated into or help fragment rigid aggregations on the basis of certain user-specified parameters that can represent van der...

The title compound, C(25)H(20)N(4), is a disubstituted methane derivative having two pyridyl-methyl-ene-amino-phenyl arms, one of which is essentially rigid as all atoms lie on a plane (r.m.s. deviation = 0.074 Å), whereas the other is twisted [dihedral angle between the phenyl-ene and pyridyl rings = 51.1 (4)°]. The angle at the methyl-ene C atom is 113.2 (2)°.

We describe cholate-based cage amphiphiles with a unique architecture that combines elements of structural rigidity and flexibility. The cage compounds are built by extending and bridging three polar chains underneath the concave steroid rings of cholate and capping with another rigid, symmetrically trifunctionalized cyanuric acid moiety. The connecting chains are varied to include, for instanc...

In the title compound, C20H17NO3 (alternative name: N-hy-droxy-9,10-dimethyl-9,10-ethano-anthracene-11,12-dicarboximide), the rigid ethano-anthracene-dicarboximide moiety has a roof-shaped geometry, the inter-planar angle between the two terminal phenyl rings being 124.9 (6)°. In the crystal, mol-ecules are linked via O-H⋯O hydrogen bonds, forming chains along [010]. C-H⋯O and C-H⋯π inter-actio...

By providing a general correspondence between Landau-Ginzburg orbifolds and nonlinear sigma models, we find that the elusive mirror of a rigid manifold is actually a supermanifold. We also discuss when sigma models with super-target spaces are conformally invariant and describe their chiral rings. Both supermanifolds with and without Kähler moduli are considered. This work leads us to conclude ...

We describe a simple modification to a rigid endoscope so as to provide both high-quality conventional and confocal images of reasonably accessible regions of the body. This versatile system uses a structured illumination approach together with a conventional incoherent illumination source. Images taken in fluorescence are presented using this combined conventional and confocal endoscope.

We explore the dynamical significance of the orbital resonances, identified in Paper I (Porco and Goldreich 1987), involving the satellites 1986U7 and 1986U8, and the €, 8, and r rings. We demonstrate that these satellites are capable of exerting torques on the € ring which supply at the inner edge, and remove at the outer edge, the unperturbed angular-momentum luminosity transported by viscous...

Weakly convex polyhedra which are star-shaped with respect to one of their vertices are infinitesimally rigid. This is a partial answer to the question whether every decomposable weakly convex polyhedron is infinitesimally rigid. The proof uses a recent result of Izmestiev on the geometry of convex caps.

BACKGROUND New insight into the 3D dynamic behavior of the mitral valve has prompted a reevaluation of annuloplasty ring designs. Force balance analysis indicates correlation between annulus forces and stresses in leaflets and chords. Improving this stress distribution can intuitively enhance the durability of mitral valve repair. We tested the hypothesis that saddle-shaped annuloplasty rings h...