OBJECTIVE To investigate whether diffusion-tensor magnetic resonance imaging and whole brain N-acetylaspartate (WBNAA) proton magnetic resonance spectroscopy can provide complementary pieces of information to achieve a better understanding of the factors associated with disability in multiple sclerosis (MS). DESIGN Cross-sectional survey. SETTING Referral hospital-based MS center. PATIENT...

Current optimal MRI identifies a relevant structural abnormality in up to 80% of patients with refractory partial seizures. Identification of a structural lesion is fundamental to pre-surgical evaluation. We used diffusion tensor imaging (DTI) and statistical parametric mapping (SPM) to examine objectively the diffusion properties, and hence structural organization, of cerebral tissue in 10 pat...

BACKGROUND AND PURPOSE Diffusion-weighted MR images have enabled measurement of directionality of diffusion (anisotropy) in white matter. To investigate differences in the anisotropy for various types of pathologic findings and the association between the anisotropy of tracts and neurologic dysfunction, we compared the anisotropy of the posterior limb of the internal capsule and the corona radi...

The measurements of CMB anisotropy have opened up a window for probing the global topology of the universe on length scales comparable to and beyond the Hubble radius. For compact topologies, the two main effects on the CMB are: (1) the breaking of statistical isotropy in characteristic patterns determined by the photon geodesic structure of the manifold and (2) an infrared cutoff in the power ...

New principles are introduced for the formulation of dynamic problems in viscoelasticity for the most general case of anisotropy. One is a variational principle derived from irreversible thermodynamics. The other a correspondence principle between viscoelasticity and elasticity. Applications to the mmics of viscoelastic plates and rods are developed as examples. The variational principles are a...

We investigate the collective oscillations of a Bose condensate in an anisotropic harmonic trap. We analytically calculate the values of the trap deformation for which the normal modes are in resonance. In presence of low-order resonances, the amplitude dependence of frequencies is strongly enhanced. We also study the transition to chaos of the collective modes as a function of the trap anisotr...

Many real-world materials exhibit significant changes in appearance when rotated along a surface normal. The presence of this behavior is often referred to as visual anisotropy. Anisotropic appearance of spatially homogeneous materials is commonly characterized by a four-dimensional BRDF. Unfortunately, due to simplicity most past research has been devoted to three dimensional isotropic BRDFs. ...

A time-domain method for calculating vibrational band profiles that simultaneously takes into account both the diagonal frequency modulations (of individual oscillators in the system) and the off-diagonal (intermolecular) vibrational coupling is developed and applied to the OH stretching band of liquid water (neat liquid H2O). It is shown that the calculated spectral features of both the isotro...