This paper studies the eeect of slow cyclic variation of parameters on the phase of the oscillating Morris-Lecar model. In chemical oscillators it is known that a phase shift, called the geometric phase shift, is observed upon return to an initial point in parameter space. We nd geometric phase shifts for a two-parameter variation in the Morris-Lecar model. As with the chemical oscillator, the ...

We studied the influence on circadian rhythms of peptides that have been reported to be colocalized in suprachiasmatic nucleus (SCN) neurons. Gastrin-releasing peptide (GRP1-27), peptide histidine isoleucine (PHI), and vasoactive intestinal polypeptide (VIP) were microinjected into the suprachiasmatic nucleus (SCN) region of Syrian hamsters free running under three different constant lighting c...

The phase shift method of wavefield extrapolation applies a phase shift in the Fourier domain to deduce a scalar wavefield at one depth level given its value at another. The phase shift operator varies with frequency and wavenumber and assumes constant velocity across the extrapolation step. We use nonstationary filter theory to generalize this method to nonstationary phase shift (NSPS) which a...

A new phase-shifting interferometry analysis technique has been developed to overcome the errors introduced by nonlinear, irregular, or unknown phase-step increments. In the presence of a spatial carrier frequency, by observation of the phase of the first-order maximum in the Fourier domain, the global phase-step positions can be measured, phase-shifting elements can be calibrated, and the accu...

Two general models for paradigm shifts, deterministic propagation model (DM) and stochastic propagation model (SM), are proposed to describe paradigm shifts and the adoption of new technological levels. By defining the order parameter m based on the diversity of ideas, Δ, it is studied when and how the phase transition or the disappearance of a dominant paradigm occurs as a cost C in DM or an i...

We show explicitly that the well-known Gouy phase shift of any focused beam originates from transverse spatial confinement, which, through the uncertainty principle, introduces a spread in the transverse momenta and hence a shift in the expectation value of the axial propagation constant. A general expression is given for the Gouy phase shift in terms of expectation values of the squares of the...

A conditional geometric phase shift gate, which is fault tolerant to certain types of errors due to its geometric nature, was realized recently via nuclear magnetic resonance (NMR) under adiabatic conditions. However, in quantum computation, everything must be completed within the decoherence time. The adiabatic condition makes any fast conditional Berry phase (cyclic adiabatic geometric phase)...

A novel quantum cryptography scheme is proposed, in which a single photon is prepared in a linear superposition state of three basis kets. A photon split to three pulses is sent from Alice to Bob, where the phase difference between sequential two pulses carries bit information. Bob measures the phase difference by passive differential phase detection. This scheme is suitable for fiber transmiss...

PURPOSE Biological soft tissues encountered in clinical and preclinical imaging mainly consists of atoms of light elements with low atomic numbers and their elemental composition is nearly uniform with little density variation. Hence, x-ray attenuation contrast is relatively poor and cannot achieve satisfactory sensitivity and specificity. In contrast, x-ray phase-contrast provides a new mechan...