University of Zimbabwe

About: University of Zimbabwe is a education organization based out in Harare, Harare, Zimbabwe. It is known for research contribution in the topics: Population & Acquired immunodeficiency syndrome (AIDS). The organization has 4378 authors who have published 6800 publications receiving 160720 citations. The organization is also known as: UZ & University College of Rhodesia and Nyasaland.

Modeling gonorrhea and HIV co-interaction.

Abstract: A mathematical model was designed to explore the co-interaction of gonorrhea and HIV in the presence of antiretroviral therapy and gonorrhea treatment. Qualitative and comprehensive mathematical techniques have been used to analyse the model. The gonorrhea-only and HIV-only sub-models are first considered. Analytic expressions for the threshold parameter in each sub-model and the co-interaction model are derived. Global dynamics of this co-interaction shows that whenever the threshold parameter for the respective sub-models and co-interaction model is less than unity, the epidemics dies out, while the reverse results in persistence of the epidemics in the community. The impact of gonorrhea and its treatment on HIV dynamics is also investigated. Numerical simulations using a set of reasonable parameter values show that the two epidemics co-exists whenever their reproduction numbers exceed unity (with no competitive exclusion). Further, simulations of the full HIV-gonorrhea model also suggests that an increase in the number of individuals infected with gonorrhea (either singly or dually with HIV) in the presence of treatment results in a decrease in gonorrhea-only cases, dual-infection cases but increases the number of HIV-only cases.

The poisoning of roots of zea ma ys by nickel ions, and the protection afforded by magnesium and calcium

Abstract: Summary The growth of seedlings oiZea mays L. has been studied in water cultures containing Ni2+, Mg2+ and Caa+ singly and in certain combinations. Root growth was reduced to half that of the controls (RG50) by as little as 01 mg I−1 Ni2+. This poisoning was prevented by 4 mg I”1 Mg2+ and by 32 mg T1 Ca2+. RG50 for Mg2+ alone was 64 mg T1 and for Ca2+ more than 1000 mg I−1. Root growth could be stopped within 8 h of exposure to 1 mg I−1 Ni2+. In the absence of Ni2+, Ca2+ protected against Mg2+ toxicity but Mg2+ did not reduce the effects when CaCl2 created osmotic loss at very high concentration. In combination, a ratio of 6:1 excess of Mg: Ca was necessary for Mg2+ to begin to reduce growth. At higher concentrations Mg2+ exerted its own toxicity despite the presence of Ca2+. When Ni2+ would otherwise have poisoned growth, Ca2+ added only to the relief of poisoning by Mg2+ if the Ca2+ was in excess by more than 4:1 over Mg2+. Thus Mg2+ appeared to be more fitted to prevent Ni2+ poisoning, yet at higher concentrations it was toxic itself, while Ca2+ could at still higher concentrations protect against both Ni2+ and Mg2+. Ni2+ poisoned growth by stiffening the expansion zone tissues and by destroying the integrity of root meristems. This latter was the first and most important toxic effect, and was achieved by arresting mitosis.

Relationship of Kaposi sarcoma (KS): Associated herpesvirus viremia and KS disease in Zimbabwe

Abstract: The relationship between Kaposi sarcoma–associated herpesvirus (KSHV) viremia and KS disease was investigated in 500 subjects who received treatment in Harare Zimbabwe. Subjects were grouped by results of human immunodeficiency virus (HIV) type 1 serological tests KS diagnosis and KS clinical stage. The plasma KSHV DNA concentration was associated with concomitant KS and HIV-1 infection (AIDS-KS; P <.001) and AIDS-KS clinical stage (P =.01 ). Plasma KSHV DNA levels were greater in AIDS-KS than in matched HIV-1–seronegative KS (P =.04). The plasma KSHV DNA level was not associated with age sex systemic symptoms or CD4+ lymphocyte count. Plasma and peripheral blood mononuclear cell KSHV DNA concentrations were linearly related (r2=.44; P <.001) and the nucleotide sequence of the K1 gene highly variable region was identical in both compartments. These findings provide evidence that KSHV viremia is common in advanced AIDS-KS in Zimbabwe and suggest a relationship between KSHV lytic replication and untreated HIV-1 infection. (authors)

Soyabeans and sustainable agriculture in southern Africa

Abstract: Maize is the dominant staple crop across most of southern Africa—it is so dominant in some areas that more than 80 per cent of the smallholder land area is planted with maize. Soyabean was identified as the crop with a potential to address the need for diversifying the cropping systems, which could assist in overcoming the pervading soil fertility constraints and could provide smallholder farmers with an opportunity to earn income while also addressing the nutritional security of households. An initiative was launched in the 1996/97 cropping season in Zimbabwe, to test soyabean as a potential smallholder crop. From an initial 55 farmers in the first year, soyabean production expanded rapidly to an estimated 10,000 farmers three years later. Since then, soyabean has diffused spontaneously to most smallholder farming areas in the higher rainfall zones of Zimbabwe. Thus, the initiative has assisted a large number of smallholders to grow soyabean, and exploded a long-held belief in Zimbabwe that soyabean is n...