W. Joubert

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In this study the cytotoxic effects of high concentrations (greater than or equal to 1 x 10(-6) M) of estradiol-17 beta (E2), 2-/4-hydroxyestradiol-17 beta (2-/4-OHE2) and 2-/3-/4-methoxyestradiol-17 beta (2-/3-/4-MeOE2) were determined on dividing MCF-7 and HeLa cells. The 2-MeOE2 metabolite followed by 2-OHE2 and E2 (in this order) proved to be extremely(More)
Injury to a peripheral nerve is, among other things, followed by degeneration of axons and myelin, as well as by a sharp increase in the number of cells (especially Schwann cells) in the part distal to the injury. The effect of allantoin--a cell proliferant--was tested on the above-mentioned reactions in the sciatic nerve of rats. The nerves were crushed(More)
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In this paper we describe the Denovo code system. Denovo solves the six-dimensional, steady-state, linear Boltzmann transport equation, of central importance to nuclear technology applications such as reactor core analysis (neutronics), radiation shielding, nuclear forensics and radiation detection. The code features multiple spatial differencing schemes,(More)
This paper presents a fully parallel implementation of the global lexicographically ordered M/ILU preconditioning for linear systems arising from structured 3-D problems. M/ILU preconditionings, which are popular on conventional serial architectures, have not been easily amenable to parallelization due to their sequentiality, leading to the need to reorder(More)
Incomplete factorization preconditioners such as ILU, ILUT and MILU are well-known robust general-purpose techniques for solving linear systems on serial computers. However, they are difficult to parallelize efficiently. Various techniques have been used to parallelize these preconditioners, such as multicolor orderings and subdomain preconditioning. These(More)
Estradiol-17 beta (E2) and the two catecholestrogens 2-OHE2 and 4-OHE2, when daily administered at low doses of 10-40 ng/rat, were cytotoxic to the seminiferous epithelium. The structural changes seen after seven days exposure included abnormal meiotic type II cells with uneven chromosome distribution, the formation of binucleated and multinucleated giant(More)
Chlorpromazine (CPZ) at dosages of 10 mg/kg body weight (b.wt.) affected the cytochemical localization of cAMP-dependent phosphodiesterase (cAMP PDE) activity in the synapses of the rat frontal cortex. Postsynaptic cAMP PDE activity was inhibited, and presynaptic activity increased. CPZ also inhibited membrane-bound ATPase activity in the frontal cortex.(More)
In this study we show that harmine treatment (10 mg/l for 2 or 24 h) of PtK2 cells had a marked effect on the localization of the nucleolar phosphoproteins C23 and B23. C23 was localized with silver staining in the fibrillar areas of completely segregated nucleoli. B23 was localized mainly on the periphery of the nucleoli with the aid of immunofluorescence.