Showing papers by "University of Zambia published in 1991"

Occurrence, clinical behaviour and management of Kaposi's sarcoma in Zambia.

Abstract: The incidence of HIV related KS has increased 50-fold since it was first recognized in Zambia in 1983. The mean age at diagnosis is 35 years for men and 28 years for women, with a sex ratio of M:F = 5:1. The most common symptoms and signs are weight loss, symmetrical lymphadenopathy, oral plaques, skin plaques in a central distribution, oedema and cough with dyspnoea. Biopsy is needed to confirm the diagnosis if disease is confined to lymph nodes. Objective regression occurs in 80% of patients receiving adequate doses of actinomycin D and vincristine (median survival time greater than 3 years for stage I or II disease and 7.5 months for stage III); epirubicin with vincristine was more effective in a phase II trial. Both treatments give good relief of symptoms, allowing patients to return to work. Clinical, histological and biological features of HIV related KS do not support conclusively its classification as a "malignant tumour". Heterosexual and perinatal transmission of HIV in Africa ensures that KS affects families, not just individuals.

Seedling development of the miombo woodland tree Julbernardia globiflora

Abstract: . The development of seedlings of the miombo tree (Julbernardia globiflora) was studied for 28 months (December 1987 - April 1990) at a Zambian grassland site from which fire has been excluded for many years. Germination occurred 10–25 days after seed planting and germination rates under laboratory and field conditions did not differ significantly. Seed germinability after one year of storage declined to 38 %. Leaf production occurred between December and April with peaks in January each year. Leaf fall occurred steadily throughout the dry season but leafless seedlings were first observed in August of each year. All seedlings had shed all their leaves by the end of November during the first year while 10% of the seedlings remained leafy throughout the second year. Annual seedling mortality was about 60 % during the first year and declined to 3 6 % during the second year. Survivorship appeared to stabilise at 3 8 % when seedlings were 5 5 - 5 9 weeks old. Every seedling experienced shoot die-back during the first hot dry season (September - November) when open-pan evaporation rates averaged 5–10 mm / day. However, shoot mortality did not necessarily result in plant mortality. Because of recurrent shoot die-back there was little increase in shoot biomass and height at the end of the second and third growing seasons. Seedlings that survived shoot die-back sprouted from roots which showed a steady annual accumulation of biomass. Early shoot die-back in seedlings of Julbernardia globiflora as documented in this study was not causedby fire but most probably by drought and / or nutritional stress.

A review of diseases of parasites of the Kafue lechwe (Kobus leche kafuensis).

Abstract: The diseases of the Kafue lechwe (Kobus leche kafuensis) are reviewed in this paper. Kafue lechwe are an important natural resource for Zambia. Bovine tuberculosis is widespread within the lechwe population and they are host to many parasites, especially the warble Strobiloestrous vanzyli.

Pattern of Urological Malignancy in Zambia A Hospital-based Histopathological Study

Abstract: Summary— The pattern of urological malignancy among the indigenous population of Zambia (determined on the basis of histopathological reports from a major national hospital during an 8-year period) is presented. A total of 6514 malignancies were observed, of which 784 (12%) were of urological origin. Bladder carcinoma, predominantly squamous type, was the commonest urological tumour (51%), followed by carcinoma of the prostate (26%), carcinoma of the penis (18%), renal tumours (4.3%) and testicular malignancy (0.7%). In nearly 32% of the bladder tumours, bilharzial ova were demonstrated histopathologically. Nephroblastoma accounted for 70% of the renal tumours and from a total of 7 cases of testicular tumours 5 were embryonal carcinoma and 2 seminoma. A brief reference is made to the pattern and aetiology of urological malignancies in some neighbouring countries.

Audit of 'surgery in general' in an African teaching hospital.

Abstract: A 1-year prospective audit of 2233 operations performed by one general surgical unit in a Central African teaching hospital is presented. In addition to the usual 'general surgical' procedures, operations also included emergency craniotomy, reconstructive surgery for open fractures, and hysterectomy. There were 37 (1.7%) postoperative deaths and 45 other deaths in non-operated patients. Ten of 14 deaths due to sepsis in the 20-40-year age group were associated with HIV infection. The implications for teaching and training of surgical specialists in the tropics are discussed.

Plant associations and rates of population interchange between two food plant areas of Acanthoplus speiseri Brancsik (Orthoptera: Tettigoniidae, Hetrodinae)

Abstract: Plant associations and rates of population interchange between two food plant areas for the armoured ground cricket, Acanthoplus speiseri Brancsik were investigated. A. speiseri was associated with 40 species of plants spread over 11 families. The ground cricket had a significantly high frequency of association at P = 0.05 with Rottboelia exaltata Linn. F. and Hyparrhenia nyassae (Rendle) Stapf. The ground cricket preferred members of the Gramineae to those of other families, 69% of the total number of ground crickets collected from the plants in this study were from grasses and among these Zea mays L. and Sorghum vulgare Pers. were opportunistic associations.

The Zambian Land Evaluation System (ZLES)

Abstract: . A Land Evaluation System for rainfed agriculture has been developed in Zambia. It is intended for use in reconnaissance and semi-detailed land evaluation studies, and works with 74 subqualities, 40 crops and four input levels. The subqualities are rated and converted into constraint classes per input level. The most limiting constraints determine the final suitability class. Expected yields per suitability class and input level are then estimated. The system was calibrated by a field study at four locations. Comparisons were made between expected and actual yields and expected and actual constraints. The range of actual yields was wider than that expected, probably because of variation in management between farmers. The average actual and expected yields were strongly correlated, but chi-squared tests showed that they were significantly different. The system generally works well in assessing land suitability for crops commonly grown in Zambia.

Youths and the Problems of Social Life in Africa: The Case of Zambia

Abstract: This article focuses on the importance of integrating youth into the larger culture, a goal that all societies struggle with. The paper concludes that youth in Zambia have similar values as their parents. As in most societies, youth in Zambia see education as the major factor in achieving personal success. However the researchers found that young people in Zambia are largely alienated from the political system. They concluded that young people in Zambia face the constant problem of balancing their dependence needs with their push towards independence. Since the means to achieve independence are not always readily available, this further strengthens the process of alienating youth from the economic, social, and political institutions.

Food plant preferences and spatial dispersion patterns of the armoured ground cricket, Acanthoplus speiseri Brancsik (Orthoptera: Tettigoniidae)

Abstract: Food plant preferences and spatial dispersion patterns of the armoured ground cricket, Acanthoplus speiseri Brancsik were investigated. The average numbers of the ground cricket found feeding on each food plant per transect in each of the three study areas were tested for differences at the 0.05 level of probability by Duncan’s multiple range test. The variance/mean ratio (S2/X) was used to analyse spatial dispersion patterns. A. speiseri fed on 12 plant species from the Compositeae, Gramineae and Solanaceae families. Hyparrhenia nyassae (Rendle) Stapf., (Gramineae) and Rottboelia exaitata Linn. f., (Gramineae), were the most preferred food plants. The armoured ground cricket densities on the two food plants were insignificantly different from each other. The cultivated plants, Zea mays L., and Sorghum vulgare Pers., were fed upon opportunistically by the ground crickets. The variance/mean ratio identified aggregation in the armoured ground cricket populations in all three study areas (S2/X > 1, P < 0.001). The significance of the findings on food plant preferences and dispersion patterns are discussed in relation to future sampling and control of A. speiseri.

Phosphate beneficiation experiments in the School of Mines, University of Zambia

Abstract: Many minerals in the earth's crust occur in relatively low abundances. In addition, mining introduces unwanted constituents in ores containing the mineral of interest. As a result, most ores must be beneficiated after mining to put them in a salable state or to allow extraction of valuable minerals to proceed. Beneficiation refers to a series of physical operations that must be performed on ores to transform them into usable products. The usable product is often a concentrate containing a high proportion of the mineral of interest compared with the ore. Strictly speaking, emphasis is generally put on physical operations to exclude many forms of chemical extraction. In this sense, beneficiation does not cover, for example, the transformation of phosphate materials into fertilizers such as SSP, TSP, or diammonium phosphate (DAP). It covers those operations performed on the ore in which a chemical change in the ore constituents does not take place. The main operations of beneficiation fall into two broad categories: processes of preparation and processes of separation.

Holographic Ellipsoidal Diffraction Grating

Abstract: In this paper a holographic ellipsoidal diffraction grating has been discutled. The conditions for stigmatic mountings have been derived. The resolution for a particular set of design parameters has been presented. It has been found that the astigmatism is zero at three wavelength.

Application of Insecticides on Cotton in Zambia: Electrodyn Swath Rows

Abstract: The charged and partially discharged Electrodyn was evaluated at various swath rows of cotton. The results of field trials suggest that under a low pest pressure, a wider swath up to two or even more rows is possible, with the current version of Electrodyn sprayer, without any significant effect on the yield of seed cotton. Similar yields of seed cotton were also obtained with both charged and partially discharged Electrodyn.

Application of Insecticides on Cotton in Zambia: Comparison of Application Techniques

Abstract: The insecticide application techniques on cotton were compared in a series of trials. The new techniques compared well with knapsack sprayers and can play an important role in the control of Heliothis and other insect pests of cotton in Zambia. The ‘Electrodyn’ knapsack and ULV sprayers gave similar yields and pest control with cypermethrin at 30 g a.i./ha. A new pyrethroid lambda cyhalothrin (12 g a.i./ha) gave similar yields to cypermethrin (30 g a.i./ha) irrespective of the spraying techniques (Electrodyn, knapsack and ULV). The new application techniques have more potential for small-scale cotton farmers in developing countries as they receive limited training on the dilution of insecticides with water and calibration of knapsack sprayers.