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.

Verb raising and subject inversion in Bantu relatives

Abstract: Verb raising and subject inversion have long been topics of theoretical linguistic interest in Romance and Germanic languages, amongst others. Bantu languages also exhibit verb raising and subject inversion, though there has been no comprehensive investigation of these phenomena, nor an explanation of crosslinguistic differences. This paper provides a unified account of verb raising and subject inversion in Bantu languages. It shows that subject inversion in Bantu matrix clauses resembles that found in Romance languages. In contrast, however, verb raising to C (similar to V2 in German matrix clauses) occurs only in embedded relative clauses, and only in some Bantu languages. A natural explanation for these phenomena comes from the fact that verb raising interacts with the prosodic status of the relative complementizer, and that Bantu matrix clauses are IPs not CPs. The paper points to the importance of competing interactions between different aspects of the grammar (e.g. prosodic words, syntax) and provides support for the notion of extended projections (Grimshaw 1993, 1997).

Horizontal accretion and stabilization of the Archean Zimbabwe Craton

Abstract: Structural-metamorphic data and mineral ages from the northern parts of the Zimbabwe craton indicate that Archean crustal formation and stabilization evolved in two stages. In the Shamva-Bindura greenstone belt, early layer-parallel shear zones began to form at 2670 Ma and accommodated imbricate stacking of oceanic and volcanic arc material between large nappe structures with felsic gneiss cores. The resultant crustal pile of anomalously hot felsic and mafic crustal slices reached isostatic and mechanical equilibrium at a thickness of 35 km. Further shortening of this pile caused strain partitioning into vertical strike-slip zones. The subsequent establishment of an equilibrium geotherm resulted in large-scale crustal melting and diapirism between 2620 and 2600 Ma. The rise of the melt and diapirs caused a second transient metamorphic imprint and much of the strain pattern regarded as typical for the Zimbabwe craton. This diapiric stage led to cooling and stabilization of the craton.

Delta Scuti Network observations of XX Pyx: detection of 22 pulsation modes and of short-term amplitude and frequency variations

Abstract: We report multisite observations devoted to the main-sequence δ Scuti star XX Pyx, conducted as the 17th run of the Delta Scuti Network. Over 125 nights a total of 550 h of usable time-series photometric B- and V-filter data were acquired involving both photoelectric and CCD measurements at eight observatories spread around the world, which represents the most extensive single time-series for any pulsating star other than the Sun obtained so far. We describe our observations and reduction methods, and present the frequency analysis of our new data. First, we detect six new pulsation and five new combination frequencies in the star's light curves. We also discover evidence for amplitude and/or frequency variations of some of the modes during the observations. These can occur on time-scales as short as 20 d and show quite diverse behaviour. To take them into account in the frequency analysis, a so-called non-linear frequency analysis method was developed, allowing us to quantify the temporal variability of the modes and to compensate for it. Following that we continue the frequency search and we also incorporate published multisite observations. In this way, we reveal three more pulsation and two more combination frequencies. In the end, we report a total of 30 significant frequencies – 22 of which correspond to independent pulsation modes. This is the largest number of independent modes ever detected in the light curves of a δ Scuti star. The frequencies of the modes show preferred separations as already suggested by previous work on this star; they are also arranged in clear patterns. These results lead to a refinement of the stellar mean density and to a new constraint on the rotation rate of XX Pyx (νrot=1.1±0.3 d−1). However, our attempts to identify the modes by pattern recognition failed. Moreover, mode identification from multicolour photometry failed as well because the high pulsation frequencies make this method unfavourable. The diverse behaviour of the amplitude and frequency variations of some of the modes leaves resonances as the only presently known possibility for their explanation.

Schistosomiasis and HIV-1 Infection in Rural Zimbabwe: Implications of Coinfection for Excretion of Eggs

Abstract: Background. Stunted development and reduced fecundity of Schistosoma parasites in immunodeficient mice and the impaired ability of human immunodeficiency virus 1 (HIV-1)-infected humans to excrete schistosome eggs have been described. This study explores the effect that HIV-1-associated immunodeficiency has on the excretion of schistosome eggs in a large cohort of coinfected individuals. Methods. In a cross-sectional survey, urine and stool samples were obtained from and HIV-1 status was determined for 1545 individuals. More extensive data, including quantitative measures of intensity of infection in schistosomiasis and immunodeficiency, were collected in the Mupfure schistosomiasis and HIV longitudinal cohort, composed of 379 participants of whom 154 were coinfected with HIV-1 and Schistosoma parasites. Results. In the cross-sectional survey, the overall prevalence of schistosomiasis was 43.4%, and 26.3% of the participants were infected with HIV-1. Schistosome infections were due to Schistosoma haematobium in 63.6% of cases, S. mansoni in 18.1% of cases, and dual infections in 18.4% of cases. Intensities of Schistosoma infections, measured by the number of eggs excreted and by the level of circulating anodic antigens, did not differ between HIV-1-negative and HIV-1-positive participants coinfected with S. haematobium, S. mansoni, or both. CD4 cell counts were significantly lower in HIV-1-positive participants and in S. mansoni-infected HIV-1-negative participants than in other participants. Conclusion. The present study suggests that adult HIV-1-related immunodeficiency does not impair the ability to excrete eggs in low-intensity infection with S. haematobium, S. mansoni, or both and that infection with HIV-1 may not have major implications for diagnosis and surveillance of schistosomiasis.