Closed orbit theory is a semiclassical technique for explaining the spectra of Rydberg atoms in external elds. We derive a new version of closed orbit theory that applies when the external elds are time-dependent. We compare the results of this theory with experiments on lithium atoms in a weak oscillating electric eld.

We identify the fine structure of resonance islands and the stickiness in chaos through recurrence time statistics (RTS), which is based on the concept of Poincaré recurrences. The projection of recurrence time statistics onto the phase space does give relevant information on the hierarchical and microstructures of the chaotic beach around the islands of a near-integrable system, the annular bi...

complex inherited diseases affected by an interaction between collective effects of the genotype at one or multiple loci either to increase or to lower susceptibility to disease, combined with a variety of environmental exposures that may trigger, accelerate, exacerbate, or protect against the disease process. the new aspects of genetic techniques have been opened for diagnosis and analysis of ...

background: breast cancer is the most common cancer and the leading cause of cancer death among the women worldwide. the risk of local and distant recurrence is the highest during the first two years following the initial treatment. very late relapse (after 12 years) is uncommon in breast cancer survivors. methods: herein, we report the characteristics and outcomes of 6 such cases of breast can...

background and purpose: the relationship between uric acid and stroke recurrence is ambiguous. some studies have explored this relationship in acute ischemic stroke but had different results. we evaluated the association of admission uric acid level with risk of stroke recurrence in patients with ischemic stroke. methods: we studied ischemic stroke patients presenting to our hospital with magne...

We describe dependencies in bivariate time series by appearance of equal or similar recurrence patterns. Various recurrence concepts and parameters are discussed. They are applied to detect synchronization in model systems of coupled oscillators and coupling in EEG data.

In this paper we prove the stability of the zero equilibria of two systems of difference equations of exponential type, which are some extensions of an one-dimensional biological model. The stability of these systems is investigated in the special case when one of the eigenvalues is equal to -1 and the other eigenvalue has absolute value less than 1, using centre manifold theory. In addition, w...

A new family of generalized Stirling and Bell numbers is introduced by considering powers (V U)n of the noncommuting variables U, V satisfying UV = V U +hV s. The case s = 0 (and h = 1) corresponds to the conventional Stirling numbers of second kind and Bell numbers. For these generalized Stirling numbers, the recursion relation is given and explicit expressions are derived. Furthermore, they a...

We study almost automorphic solutions of recurrence relations with values in a Banach space V for quasilinear almost automorphic difference systems. Its linear part is a constant bounded linear operator Λ defined on V satisfying an exponential dichotomy. We study the existence of almost automorphic solutions of the non-homogeneous linear difference equation and to quasilinear difference equatio...

We study a system of delay difference equations modeling four-dimensional discrete-time delayed neural networks with no internal decay. Such a discrete-time system can be regarded as the discrete analog of a differential equation with piecewise constant argument. By using semicycle analysis method, it is shown that every bounded solution of this discrete-time system is eventually periodic. The ...