Differences in the in vitro response of lymphocytes from leukotic and normal cattle to concanavalin A

The response of cultured peripheral blood lymphocytes from cattle affected with bovine leukosis and from animals free of detectable leukosis to the nonspecific mitogen Concanavalin A ws determined by the measurement of 3H-thymidine incorporation. The stimulatory effect of the mitogen was significantly decreased in leukotic lymphocytes in comparison with normal lymphocytes. This depression was dependent on the severity of the disease. Leukotic lymphocytes showed high basal levels of spontaneous thymidine uptake possibly due to their low maturity. It is suggested that leukotic lymphocytes are not stimulated by Concanavalin A because of their B cell characteristics. A residual cell population of normal reacting lymphocytes--enriched by nylon wool column fractionation--is probably responsible for the remaining but weak in vitro reaction of leukotic lymphocytes.     

Construction of Differential Material Matrices for the Orthogonal Finite-Integration Technique With Nonlinear Materials

The linearization of an electromagnetic formulation by the Newton method can be expressed similarly as for the linear case, by introducing differential material matrices. For the case of the finite-integration technique applied to an orthogonal grid, the chord material matrix is diagonal whereas the differential material matrices includes off-diagonal bands, representing the cross-directional coupling introduced by the nonlinearity. An approximative Newton method based on a unidirectional differential material matrix yields a diagonal matrix, which has a higher computational efficiency but may lead to a degenerated convergence.     

Calculation of scattering parameters by orthogonal expansion and finite integration method

Field computations by mathematical and numerical methods are presented in the time and frequency domain. The techniques used are discretization and modal expansion. The effects of modelling and frequency range on the accuracy and calculation requirements are investigated and discussed. By way of application, several results of RF-filter designs are presented, where these methods have been implemented in CAD programs.