Mean first passage times reconstruct the slowest relaxations in potential energy landscapes of nanoclusters.

Relaxation modes are the collective modes in which all probability deviations from equilibrium states decay with the same relaxation rates. In contrast, a first passage time is the required time for arriving for the first time from one state to another. In this paper, we discuss how and why the slowest relaxation rates of relaxation modes are reconstructed from the first passage times.

Renormalized perturbation approach to instanton-noninstanton transition in nearly integrable tunneling processes.

A renormalized perturbation method is developed for quantum maps of periodically kicked rotor models to study the tunneling effect in the nearly integrable regime. Integrable Hamiltonians closely approximating the nonintegrable quantum map are systematically generated by the Baker-Hausdorff-Campbell (BHC) expansion for symmetrized quantum maps. The procedure results in an effective integrable renormalization, and the unrenormalized residual part is treated as the perturbation.

Slowest kinetic modes revealed by metabasin renormalization.

Understanding the slowest relaxations of complex systems, such as relaxation of glass-forming materials, diffusion in nanoclusters, and folding of biomolecules, is important for physics, chemistry, and biology. For a kinetic system, the relaxation modes are determined by diagonalizing its transition rate matrix. However, for realistic systems of interest, numerical diagonalization, as well as extracting physical understanding from the diagonalization results, is difficult due to the high dimensionality.

[A Case of Hypertrophic Pachymeningitis with Symptomatic Venous Congestion due to Sinus Stenosis].

We report a patient with hypertrophic pachymeningitis and symptomatic stenosis of the superior sagittal sinus. A 71-year-old man presented with right hemiparesis, sensory-dominant aphasia, and right hemispatial neglect that had been worsening over 2 weeks. Computed tomography showed isodense crescent-shaped lesions deforming the surface of the left cerebral hemisphere, mimicking a subdural hematoma with atypical perifocal edema in the left parietal lobe.