SUMMARYAn approximation based on multiple function and gradient information is developed using Hermite interpolation concepts. The goal is to build a high-quality approximation for complex and multidisciplinary design optimization problems employing analysis such as aeroservoelasticity, structural control, probability, etc. The proposed multidimensional approximation utilizes exact analyses data generated during the course of iterative optimization. The approximation possesses the property of reproducing the function and gradient information of known data points. The accuracy of the new approach is compared with linear, reciprocal and other standard approximations. Because the proposed algorithm uses more data points, its efficiency has to be compared in the context of iterative optimization.

To study interaction of specific antibodies with the GABA receptor/channel, antisera were raised against the extracellular domains of the GABAA receptor/channel beta2 subunit, gamma2 subunit and the GABAC receptor/channel rho1 subunit. The specificity of the antibodies was characterized by immunocytochemistry and by Western blotting of transfected FDC-P1 cells expressing recombinant GABA receptor/channel subunits. The effects of the antibodies on whole-cell currents in Xenopus laevis oocytes expressing homomeric recombinant GABA receptor/channel beta2, gamma2, and rho1 were studied using two-microelectrode voltage clamp. In the absence of GABA, anti-alpha2, anti-gamma2, and anti-rho1 antisera elicited whole-cell currents in oocytes expressing beta2, gamma2, and rho1 subunits, respectively. The effect of antibody on channel activation was concentration-dependent. The whole-cell currents induced by anti-beta2 and anti-gamma2 were several-fold greater than those induced by application of 100 microm GABA. In Xenopus oocytes expressing recombinant rho1 subunits, GABA-induced whole-cell currents were inhibited by the anti-rho1 antibody. In contrast, the GABA-induced whole-cell currents were potentiated several-fold by anti-beta2 and anti-gamma2 antibodies in Xenopus oocytes expressing homomeric beta2 and gamma2 subunits. Our studies indicate that antibodies specific to the N-terminal domain of GABA receptor/channel subunits can modulate the neurotransmitter receptor function.

The emphasis of this paper is on developing suitable intervening variables and constraint approximations for structural reliability analysis. Traditionally, these procedures are used in structural optimization, whereas this research work adopts these concepts to safety index and failure probability computations. The use of these concepts enables the development of an efficient and stable iteration algorithm for identifying the most probable failure points (MPPs) of the limit state functions. An approximate second-order failure probability is calculated at this MPP with no extra computations of the limit state function and gradients. The efficiency and accuracy of the proposed algorithm are demonstrated by several examples with highly nonlinear, complex, explicit/implicit performance functions.