Search

This technical note presents a proof of the equivalence between the strict passivity of linear time-invariant (LTI) controllable and observable systems and the strict positive realness of their transfer function matrices, where the direct feedthrough $D$ is possibly a non-zero matrix. Although both properties guarantee asymptotic stability, the former is a time domain condition and the latter is a frequency domain concept. A numerical example illustrates our main results. [ABSTRACT FROM AUTHOR]

Neurocysticercosis (NCC) is the most common helminthic brain infection related to epilepsy. Only albendazole (ABZ) and praziquantel are used in its treatment. The development of new therapeutics has been encouraged. Taenia crassiceps cysticerci intracranial infection is the experimental model used in NCC studies. This study evaluated the histopathology of the brains of BALB/c mice experimentally infected with T. crassiceps cysticerci after the treatment with the ABZ/nitazoxanide (NTZ) combination. Thirty days after the inoculation the mice received an oral single dose of the ABZ/NTZ combination (40 mg kg−1 each). The control groups were treated with: NaCl 0.9%; ABZ or NTZ. The histopathologic evaluation of the brains was performed 24 h after treatment. The ABZ treatment induced discrete mononuclear inflammatory infiltration, meningitis, gliosis, hyperaemia and hippocampus compression; moderate ependimitis and oedema. The NTZ treatment induced accentuated inflammatory infiltration, foamy macrophages, ependimitis, choroiditis, gliosis and hyperaemia and moderate oedema. The ABZ/NTZ combination treatment induced a significant decrease in the polymorphonuclear inflammatory infiltration, ependimitis, choroiditis, gliosis, hyperaemia and ventriculomegaly in comparison with the other groups. The cysticerci showed destruction of the tegument not observed in other groups. The ABZ/NTZ combination is efficient as the parasite showed signs of destruction and lower damage to the host's tissue. [ABSTRACT FROM AUTHOR]

The leading-edge contamination (LEC) problem of an infinite-swept wing is computed by solving the full two-dimensional Navier–Stokes equation using a very high spectral accuracy compact scheme. The initial condition is given by the steady attachment-line boundary layer forming over the leading-edge of an infinite swept wing or a yawed cylinder. The contamination is shown as due to either a convecting or a stationary vortex far outside the attachment-line boundary layer at the leading edge. This mechanism is proposed to account for the sub-critical instability onset observed for attachment-line boundary layer. (The criticality is for Reynolds number (based on momentum thickness) exceeding 100––an empirically suggested value based on earlier experiments.) The presented results show the problem to be essentially two-dimensional. Inflow and outflow of computational domain are chosen so that we consider cases of both sub- and super-critical instabilities. The receptivity mechanism of leading-edge contamination for both cases is investigated with respect to different parameters. Finally, we have also analyzed the computed solutions by proper orthogonal decomposition (POD) to highlight the low-dimensional nature and to provide a quantitative measure of leading-edge contamination events. [Copyright &y& Elsevier]