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.

Effect of Solvent Type on Total Phenolic Content and Free Radical Scavenging Activity of Black Tea and Herbal Infusions

Abstract: The objective of the study was to determine and compare the effect of several solvents namely hot water, 50 % methanol, ethanol, 50 % ethanol, acetone, 50 % acetone and ethyl acetate on phenolic composition and free radical scavenging activity in black tea and selected herbal infusions from Zimbabwe and Brazil. For the black tea, made from Camellia sinensis, Quickbrew™ was used. Zimbabwean herbal infusions used were Lippia javanica and Ficus sycamore while those from Brazil were Syzygium jambolanum, Cuphea carthagenensis and Ilex paraguariensis. Total phenolic content and free radical scavenging activity were determined using Folin-Ciocalteu and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, respectively. IC50 values for each solvent were calculated and used to interpret radical scavenging activity. Aqueous organic solvents extracted higher quantities of phenolic compounds than in their absolute organic nature. Acetone (50 %) extracted a higher total phenolic content (TPC) in C. sinensis, L. javanica and I. paraguariensis. Hot water extracted the highest TPC in F. sycamore and S. jambolanum while 50 % ethanol was highest in C. carthagenensis. Free radical scavenging activity (FRSA) was not necessarily in the same order as TPC, indicating that high TPC does not always mean high FRSA and vice versa. The highest FRSA for S. jambolanum and C. carthagenensis extracts was in 50 % ethanol, F. sycamore in 50 % methanol, and I. paraguariensis, C. sinensis and L. javanica extracts in 50 % acetone. Ethyl acetate recorded the lowest TPC and FRSA in all plant samples analysed. Generally, solvent used affected TPC and free radical scavenging activity. Organic solvents may need to be separated from phenolics after extraction, as some of them namely acetone, methanol and ethyl acetate can be toxic to humans. Water and ethanol are the least toxic solvents which may need no further separation from extracts.

The Legacy of Colonialism: Perceptions of the Cultural Heritage in Southern Africa, with Special Reference to Zimbabwe

Abstract: Reflexion sur les suites du colonialisme au Zimbabwe, sur le developpement des musees et sites archeologiques dans le cadre de la restauration et de la preservation des valeurs culturelles traditionnelles et sur les conflits d'interets rencontres avec les populations d'origine europeenne.

Contextual and psychosocial influences on antiretroviral therapy adherence in rural Zimbabwe: towards a systematic framework for programme planners

Abstract: SUMMARY Great progress has been made in achieving universal access to antiretroviral therapy (ART). However, for successful viral suppression, patients must adhere to rigid and complex treatment regimens. With three quarters of antiretroviral (ARV) users in Africa adhering successfully, African countries have achieved extraordinary levels of adherence given the levels of poverty in which many ARV users live. Nevertheless, one quarter of ARV users still struggle to adhere and run the risk of experiencing viral replication, clinical progression or even drug resistance. Much has been written about ART adherence, but little has been done to systematically categorise the spectrum of factors that influence ART. In this paper, we use a Zimbabwean case study to develop a framework for ART programme planners and implementers seeking to identify and tackle social obstacles to adherence. We draw on interviews and group discussions with 25 nurses and 53 adult ARV users, which we analysed through a three‐tiered thematic approach, allowing us to categorise our findings into broader dimensions that can transcend our case study and be applied elsewhere. Our findings suggest that ART adherence is influenced by the material, symbolic, relational and institutional contexts in which ARV users live as well as the patient’s motivation, participation and psychosocial responses to ART. This framework allows us to examine both the social context in which ART programmes are located and the psychosocial factors that influence patient behaviours. We offer this framework as a resource for ART programme planners and implementers seeking to improve ART compliance in resource‐poor settings. Copyright © 2011 John Wiley & Sons, Ltd.

Litter from a tropical savanna woodland (Miombo) : chemical composition and C and N mineralization

Abstract: The decomposability of 15 litter types from four miombo woodland species, two tree species, Brachystegia spiciformis and Julbernardia globiflora, a grass species, Dactylotaenium aegyptium, and a sedge, Bulbostylis megastachys, was determined on the assumption that different plant components could be used as predictors for C and N mineralization. The chemical composition of the litter, in terms of lignin, polyphenol, cellulose and total C and N contents was determined. The C and N mineralization patterns of the litter were also investigated during 75 days of aerobic laboratory incubation with soil and correlated with the initial composition. The litter materials contained between 40–51% organic C and total N contents of 13 of the 15 litter types were low, ranging from 0.47% for D. aegyptium leaf to 1.29% for lichens + bark fragments found associated with B. spiciformis stem. The lignin contents ranged from 0.03% in lichens + bark fragments to 16.5% in twig litter from B. spiciformis. Polyphenol contents ranged from 0 to 6%, with the highest values being found in twigs and pods. Cumulative C mineralization data were fitted to first-order kinetics estimating the decomposition parameters. Seed litter from B. spiciformis evolved more CO2, 68.8% of initial C, than all the other litter materials tested. It was found that identical plant parts from the two tree species showed a similar rate of C mineralization, which was as follows: seed > lichens + bark fragments > tree leaflet litter > rachis litter > twig litter. Cellulose, which has received less attention in the literature, was found to influence both C and N mineralization patterns among other natural biopolymers (P < 0.001) but the content of ash-free available C, which was calculated as the difference between total C and lignin C + polyphenol C + cellulose C on an ash-free basis, had the highest R2 value (0.910) for C mineralization and total N had the highest R2 value (0.881) for N mineralization. Net N mineralization during 75 days was only apparent in 6 of the 15 litter samples, with results ranging from 0.2% of initial N in lichens + bark fragments from J. globiflora to 46% of initial N in B. spiciformis seed. The remaining samples immobilized N during the 75 days. Net N mineralization-immobilization was better correlated with the lignin C-to-N ratio (R2 = 0.695; P < 0.001) and the (lignin + polyphenol) C-to-N ratio (R2 = 0.688; P < 0.001) than the lignin-to-N ratio (R2 = 0.656; P < 0.001) or lignin + polyphenol-to-N ratio (R2 = 0.613; P < 0.001). Total N concentrations, C-to-N ratios and cellulose-to-N ratios appeared to be good predictors of N mineralization rates of the N-poor woodland (P < 0.001). The major part of miombo litter may not be a source for mineral N during the first 2–3 months after addition but the fractionation of litter into different C fractions gave a good indicator of potential C mineralization.