This study was designed to examine the nature of neural circuits involved in subcortical inter-limb coordination and reflex modulation mechanisms of locomotion. These circuits, called central pattern generators (CPGs), are believed to receive tonic input and generate rhythmically alternating sets of commands. Although CPGs have been theorized to exist in humans, their potential dual role in int...

Neuronal mechanisms in nervous systems that keep intersegmental phase lags the same at different frequencies are not well understood. We investigated biophysical mechanisms that permit local pattern-generating circuits in neighboring segments to maintain stable phase differences. We use a modified version of an existing model of the crayfish swimmeret system that is based on three known coordin...

A significant lag phase was observed in the accumulation of product for the reaction catalyzed by pyruvate decarboxylase (PDC) purified from mature maize kernels. The effects of pH, pyruvate, potassium chloride, PDC concentration, and Mg(2+)-thiamine pyrophosphate upon this lag and upon the observed cooperativity were investigated. PDC preincubated with Mg(2+)-thiamine pyrophosphate for six day...

We investigated protein and gene expression in the lag phase of Lactococcus lactis subsp. lactis CNRZ 157 and compared it to the exponential and stationary phases. By means of two-dimensional polyacrylamide gel electrophoresis, 28 highly expressed lag-phase proteins, implicated in nucleotide metabolism, glycolysis, stress response, translation, transcription, cell division, amino acid metabolis...

In this paper we study the spatial behavior of solutions to the equations obtained by taking formal Taylor approximations to the heat conduction dual-phase-lag and three-phaselag theories, reflecting Saint-Venant’s principle. Depending on the relative order of derivation with respect to the time we propose different arguments. One is inspired by the arguments for parabolic problems and the othe...

In the present work, a modified model of heat conduction including higher order of time derivative is derived by extending Green and Naghdi theory without energy dissipation. We introduce two phase lag times to include the thermal displacement gradient and the heat flux in the heat conduction and depict microscopic responses more precisely. The constructed model is applied to s...

in this paper a new method is introduced and investigated for removing the destabilizing effects of time-delay parameter in control loops. the concept of the method is taken from the knowledge concerning the dynamic behaviour of irrational transfer functions (ir-tf), which is discussed and investigated elswhere in frequency response domain and is explained briefly here. ir-tfs, which are well c...