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.

Valuing Volatility and Variance Swaps for a Non‐Gaussian Ornstein–Uhlenbeck Stochastic Volatility Model

Abstract: Following the increasing awareness of the risk from volatility fluctuations, the market for hedging contracts written on realized volatility has surged. Companies looking for means to secure against unexpected accumulation of market activity can find over‐the‐counter products written on volatility indices. Since the Black and Scholes model require a constant volatility the need to consider other models is obvious. Swaps written on powers of realized volatility in the stochastic volatility model proposed by Barndorff‐Nielsen and Shephard are investigated. A key formula is derived for the realized variance able to represent the swap price dynamics in terms of Laplace transforms, which makes fast numerical inversion methods viable. An example using the fast Fourier transform is shown and compared with the approximation proposed by Brockhaus and Long.

Selection in the Making: A Worldwide Survey of Haplotypic Diversity Around a Causative Mutation in Porcine IGF2

Abstract: Domestic species allow us to study dramatic evolutionary changes at an accelerated rate due to the effectiveness of modern breeding techniques and the availability of breeds that have undergone distinct selection pressures. We present a worldwide survey of haplotype variability around a known causative mutation in porcine gene IGF2, which increases lean content. We genotyped 34 SNPs spanning 27 kb in 237 domestic pigs and 162 wild boars. Although the selective process had wiped out variability for at least 27 kb in the haplotypes carrying the mutation, there was no indication of an overall reduction in genetic variability of international vs. European local breeds; there was also no evidence of a reduction in variability caused by domestication. The haplotype structure and a plot of Tajima's D against the frequency of the causative mutation across breeds suggested a temporal pattern, where each breed corresponded to a different selective stage. This was observed comparing the haplotype neighbor-joining (NJ) trees of breeds that have undergone increasing selection pressures for leanness, e.g., European local breeds vs. Pietrain. These results anticipate that comparing current domestic breeds will decisively help to recover the genetic history of domestication and contemporary selective processes.

Effects of chromium III on fasting blood glucose, cholesterol and cholesterol HDL levels in diabetics.

Abstract: Chromium deficiency; Malnourishment; Glucose tolerance; Diabetes; Developing world; Zimbabwe; Fasting; Cholesterol; HDL; Blood sugar;

Integrating legumes to improve N cycling on smallholder farms in sub-humid Zimbabwe: resource quality, biophysical and environmental limitations

Abstract: The release of mineral-N in soil from plant residues is regulated by their ‘quality’ or chemical composition. Legume materials used by farmers in southern Africa are often in the form of litter with N concentration 5 Mg ha-1) and improved N cycling significantly (>150 kg N ha-1) on the clay loam soil, but adapted poorly on the sandier soil. There was a rapid N accumulation in the topsoil at the beginning of the rains in plots where large amounts of Sesbania or Acacia biomass had been incorporated. Despite the wide differences in resource quality between these two, there was virtually no difference in N availability in the field as this was, among other factors, confounded by the quantity of N added. A substantial amount of the nitrate was leached to greater than 0.4 m depth within a three-week period. Also, the incidence of pests in the first season, and drought in the second season resulted in poor nitrogen use efficiency. Our measurements of gaseous N losses in the field confirmed that N2O emissions were <0.5 kg N ha-1. As we had measurements of all major N flows, we were able to construct overall N budgets for the improved fallow – maize rotation systems. These budgets indicated that, in a normal rainfall season with no major pest problems, reducing nitrate leaching would be the single largest challenge to increased N recovery of added organic N in the light textured soils

Medically unexplained somatic symptoms in different cultures. A preliminary report from phase I of the World Health Organization International Study of Somatoform Disorders.

Abstract: The World Health Organization has recently launched an international study of somatoform disorders in different cultures. Five centres representing distinct cultures participated in phase I of the project, the main objective of which was to test the cross-cultural applicability and reliability of instruments for the assessment of somatoform disorders. The analysis of the assessed somatic symptoms showed that various aches and pains in different parts of the body represented cross-culturally the most frequent symptoms for which there was no medical explanation. Such symptoms may indicate the presence of an underlying mental disorder but can also represent a means for culture-specific expression of psychosocial distress. This bears particular significance for health professionals in primary and general medical care, who are most likely to encounter patients presenting with multiple, persistent and medically unexplained somatic symptoms.