The quantitative concepts used to reason about gene regulation largely derive from bacterial studies. We show that this bacterial paradigm cannot explain the sharp expression of a canonical developmental gene in response to a regulating transcription factor (TF). In the absence of energy expenditure, with regulatory DNA at thermodynamic equilibrium, information integration across multiple TF bi...

We focused our attention on Ca(2+) release from the endoplasmic reticulum through a cluster of inositol(1,4,5)-trisphosphate (IP(3)) receptor channels. The random opening and closing of these receptors introduce stochastic effects that have been observed experimentally. Here, we present a stochastic version of Othmer-Tang model (OTM) for IP(3) receptor clusters. We address the average behavior ...

The proposed scheme is a multi level steganography in which steganography is done at two places. The cover image is divided into fixed size blocks and then Discrete Cosine Transformation is applied into each block of cover image. The resulting DCT coefficients are quantized using quantization process. In the quantized DCT coefficient, the encrypted data file is embedded by using Least Significa...

The initial rates of isomerization between glucose 6-phosphate and fructose Q-phosphate catalyzed by Bacillus stearothermophilus pbospboglucose isomerase (PGI) were measured in both the forward and reverse reactions. Although B. stearothermophilus PGI is a tetrameric enzyme, the reaction rate vs substrate concentration curves for both reactions exhibited Michaelis-Menten kinetic behavior. This ...

Dose-response curves for inhibitors (drugs) generally are analyzed by means of four-parameter fits, yielding IC(50), background, amplitude, and Hill coefficient. Hill coefficients not equal1 contradict 1:1 competition. If binding of substrates to proteins is a stepwise process where initial binding to initial locations (patches) leads to strong binding on defined sites, then drugs (non-endogeno...

Thimerosal, a thiol-reactive reagent, has been shown to increase the cytosolic Ca2+ concentration in a variety of cells by sensitizing inositol 1,4,5-trisphosphate (InsP3) receptors. Thimerosal can have both sensitizing (at concentrations of <2 microM) and inhibitory (at concentrations of >2 microM) effects on InsP3-induced Ca2+ release (IICR) from cerebellar microsomes. Transient kinetic studi...

We consider the Hill four-body problem where three oblate, massive bodies form a relative equilibrium triangular configuration, and 4th, infinitesimal body orbits in neighborhood of smallest bodies. regularize collisions between body, via McGehee coordinate transformation. describe corresponding collision manifold show that it undergoes bifurcation when oblateness coefficient passes through zer...

Recent work indicates that endotoxemia elicits severe reductions in skeletal muscle force-generating capacity. The subcellular alterations responsible for these decrements have not, however, been fully characterized. One possibility is that the contractile proteins per se are altered in endotoxemia and another is that the mechanism by which these proteins are activated is affected. The purpose ...

Amidophosphorihosyltransferase (EC 2.4.2.14) has been partially purified from pigeon liver, and ligand-induced alterations in molecular and kinetic properties have been studied. In Tris-HCl buffer the predominant form of’ the enzyme has an sZO,w of 5.9 * 0.7, Stokes radius of 42 A, and estimated molecular weight of 102,000. Incubation with phosphoribosylpyrophosphate (PP-ribose-P) results in an...

BACKGROUND Information on molecular targets that may be involved in the neurotoxicity of bupivacaine is limited. Suppression of Kv3 channels has been demonstrated to result in abnormal patterns in the electroencephalogram and in seizures. Inhibition of Kv3 channels by bupivacaine may consequently contribute to its neuroexcitatory side-effects. Data on the effects of bupivacaine on these potassi...