In this paper, we propose to compare three diffusion models to track the portion of the corticospinal tract dedicated to the hand motor function (called hand motor fibers hereafter), using diffusion, functional and anatomical MRI. The clinical diffusion data have few gradient directions and low b-values. In this context, we show that a newly introduced model, called diffusion directions imaging...

has been a major hurdle on the use of these compensating potentials more generally in constrained MD simulations. Rigid internal constraints are used in molecular models to speed up molecular dynamics (MD) simulations. It is well recognized that This paper analyzes the structure of the compensating statistical averages from such constrained MD simulations differ by potential and its gradient an...

In SU(2) gluodynamics we calculate the gluon polarization tensor in an Abelian homogeneous magnetic field in one-loop order in the Lorentz background field gauge. It turned out to be non transversal and consisting of ten tensor structures and corresponding form factors four in color neutral and six in color charged sector. Seven tensor structures are transversal, three are not. The non transver...

In this paper, on the basis of a new strain gradient elasticity theory, wave propagation in rectangular nanoplates by considering in-plane magnetic field is studied. This strain gradient theory has two gradient parameters and has the ability to compare with the nonlocal elasticity theory. From the best knowledge of author, it is the first time that this theory is used for investigating wave pro...

The Wasserstein distance on multivariate non-degenerate Gaussian densities is a Riemannian distance. After reviewing the properties of the distance and the metric geodesic, we derive an explicit form of the Riemannian metrics on positive-definite matrices and compute its tensor form with respect to the trace scalar product. The tensor is a matrix, which is the solution of a Lyapunov equation. W...

We develop a mathematical framework for quantifying and understanding multidimensional frequency modulations in digital images. We begin with the widely accepted definition of the instantaneous frequency vector (IF) as the gradient of the phase and define the instantaneous frequency gradient tensor (IFGT) as the tensor of component derivatives of the IF vector. Frequency modulation bounds are d...

Pulsed field gradient nuclear magnetic resonance methods combined with nuclear magnetic resonance imaging were used to determine the water diffusion anisotropy in perfused rat hearts at 37°C. It was found that the observed diffusion coefficient DaPP (apparent diffusion coefficient) depends on the orientation of the applied gradient g. When g is parallel to the epicardial surface, the observed d...

Vesselness filters aim at enhancing tubular structures in medical images. The most popular vesselness filters are based on eigenanalyses of the Hessian matrix computed at different scales. However, Hessian-based methods have well-known limitations, most of them related to the use of second order derivatives. In this paper, we propose an alternative strategy in which ring-like patterns are sough...

The magnetic field gradient produced by an electromagnet gripper head depends on its design. Stochastic Methods offer certain robustness to the design optimization process. In this paper, Improved Discrete Particle Swarm Optimization (IDPSO) searching technique is applied to the shape and magnetic field gradient optimization of an electromagnet head. The magnetic field and forces are computed u...