Showing papers by "Makerere University published in 1972"

Studies on mixtures of maize and beans (Phaseolus vulgaris) with particular reference to plant population

Abstract: Two experiments are described in which the possible yield benefits of mixing maize and beans were examined under intensive farming conditions. A ‘replacement series’ of pure maize, two-thirds maize/one-third beans, one-third maize/two-thirds beans and pure beans was used at four plant populations. A high level of nitrogen was applied on the maize to eliminate the effects of nitrogen transfer from the beans.Yields of the mixtures were up to 38% higher than could be achieved by growing the crops separately. It is concluded that this occurred because the mixtures achieved a greater utilization of environmental resources; it is suggested that, because of the marked height differences of the two crops, an increased utilization of light was probably a major contributing factor. The need for high populations in mixtures is indicated, partly because the largest yield increases were achieved at high populations and partly because the mixtures required a higher population pressure to produce their maximum yield.The maize was found to have the higher relative competitive ability, and this increased with increase in plant population pressure. It is suggested that this was probably due to the shading effect which the maize had on the beans. The effects of a change in relative competitive abilities, or in relative selling prices, on the optimum proportion of two species in a mixture are also considered.

Studies on mixtures of dwarf sorghum and beans ( Phaseolus vulgaris ) with particular reference to plant population

Abstract: An experiment is described in which the possible yield benefits of mixing dwarf sorghum and beans were examined under intensive farming conditions. A ‘replacement series’ of pure sorghum, two-thirds sorghum/one-third beans, one-third sorghum/twothirds beans and pure beans was used at four plant populations. A high level of nitrogen was applied to the sorghum to eliminate the effects of nitrogen transfer from the beans. Yields of the mixtures were up to 55% higher than could be achieved by growing the crops separately. As with some earlier maize/beans experiments (Willey & Osiru, 1972), it is concluded that these yield increases must have been due to a greater utilization of environmental resources. It is suggested that the main factors which made this possible were probably the different rooting depths of the two crops and their different growth cycles. In agreement with the earlier experiments, mixtures which consisted of two-thirds sorghum/one -third beans gave greatest yield increases at high populations and also had a higher optimum population than the pure stands. However, no such trends were apparent in the mixtures which consisted of one-third sorghum/two-thirds beans. For both species intra-specific competition was greater than inter-specific competition. In contrast to the earlier maize/beans experiments, the relative interspecific competitive abilities of the species changed with change in the initial proportions of species in the mixtures. In the two-thirds sorghum/one-third beans mixtures the sorghum was the more competitive species, whilst in the one-third sorghum/two-thirds beans mixtures the bean was the more competitive species. Also in contrast to the maize/beans experiments, these relative competitive abilities were not affected by change in theoverall plant population pressure.

The epidemiology and consequences of Schistosoma mansoni infection in West Nile, Uganda: I. Field studies of a community at Panyagoro

Abstract: A Jonam fishing community at Panyagoro, West Nile District, Uganda, was studied and the 235 people examined showed a very high infection rate with S. mansoni . The mean egg output of males over 5 years old was 1112 eggs/g. and of females was about half this level. High egg output levels were maintained into old age. Diarrhoea with blood and abdominal pain were extremely frequent. Hepatosplenomegaly, eosinophilia and anaemia were common and particularly occurred together in people who looked ill and had marked abdominal distension and ascites. Malaria was endemic but other possible causes of these findings were largely absent. Much disease is probably due to S. mansoni which is here causing disease of public health importance in sub-Saharan Africa.

Studies in Kaposi's sarcoma. Postmortem findings and disease patterns in women

Abstract: Six hundred twenty-four cases of Kaposi's sarcoma occurring in Ugandan Africans have been reviewed. Thirty-four patients came to necropsy, and almost all were found to have visceral lesions. Patients with nodular cutaneous disease usually had a long history of disease and often had small numbers of visceral nodules which only very seldom produced symptoms. Locally aggressive tumors occurred more commonly in Ugandans than in whites; in spite of locally destructive growth, they seldom metastasized widely and were often present for many years. Young people with generalized involvement were seen rarely and most of these patients had had malaria. The pattern of disease was of two types: in African children, tumor was found predominantly in nodes, whereas in young adults involvement of skin nodes and viscera was seen. The prognosis in such cases was poor. Africans seem to be less likely to develop a second neoplasm than whites. Females suffer from Kaposi's sarcoma less frequently than males but are relatively more likely to develop rapidly fatal generalized forms of the disease.

Chemotherapy of Burkitt's lymphoma.

Abstract: Results of treatment of 117 patients with Burkitt's lymphoma followed for a minimum of 18 months were analyzed. All patients were clinically staged and treated according to randomized clinical trials. Sixteen patients (14%) died within the first week of treatment of causes related to widespread tumor. Ninety-five of the remaining 101 evaluable patients achieved complete remission (95%), while six had partial responses and eventually died. The frequency of relapse was significantly lower in patients with localized tumors (39%) as compared to patients with generalized disease (70%), but was unaffected by the intensity of the initial therapeutic regimen. Patients who developed early relapse (within 10 weeks of first treatment) had a less favorable prognosis than patients who relapsed beyond this period. Preliminary results of a current immunotherapeutic trial using BCG following cyclophosphamide-induced remission suggest a protective effect of this treatment on the development of extradural relapse. These results provide guidelines for future therapeutic approaches which are discussed.

The measurement and prediction of available water capacity of ferrallitic soils in uganda

Abstract: Summary Field capacity was measured directly, and soil moisture characteristics were determined on undisturbed cores, for a wide textural range of ferrallitic soils in Uganda. The initial moisture conditions of the soils were shown to affect results and thus standardized procedures were adopted for field and laboratory determinations. Laboratory estimates of field capacity for undisturbed and disturbed samples were shown to be unreliable, but a correction factor was found which improved them. There was no single moisture tension for undisturbed core samples that corresponded to field capacity. Particle-size composition could be related to field capacity, permanent wilting-point, and available water capacity by multiple regression equations having correlation coefficients of 0.96, 0.98, and 0.88 respectively. The relationships predicting available water capacity were different from those found for soils in England, but those for field capacity and permanent wilting-point were similar. Particle-size analyses were carried out using three methods of dispersion of different efficiencies. Particle-size composition following gentle dispersion by shaking soil with distilled water was poorly correlated with moisture-holding properties. There was little advantage in using vigorous ultrasonic dispersion compared with overnight shaking with sodium hexametaphosphate. Two soils formed on alluvial deposits with kaolinite the only clay mineral, and one soil with montmorillonite the dominant clay mineral, showed markedly different relationships between moisture-holding properties and particle-size composition.

The distribution of Buruli disease in Uganda

Abstract: The distribution and incidence of Buruli disease throughout Uganda during 1970 have been described. The distribution can be related to the hypothesis that the disease became endemic in Uganda as a result of flooding during 1962–1964 and subsequently extended its distribution away from the Nile. It is suggested that the distribution is dependent upon variations in the characteristics of permanent swamps. Among males there are proportionately more older children and adults affected in areas of low incidence.

Hepatitis-associated Antigen and Antibody in Uganda: Correlation of Serological Testing with Histopathology

Abstract: Histopathological findings in 91 Ugandan patients with cirrhosis were studied in relation to serological tests for the hepatitis-associated antigen (H.A.A.) and antibody (anti-H.A.A.). H.A.A. was present in 30 (32·9%) of the 91 patients as opposed to 7 (3·1%) out of 224 controls drawn from the same population (P

Burkitt's lymphoma and malaria

Abstract: An analysis of malarial parasitaemia, splenomegaly, antimalarial antibodies, immunoglobulin levels, and reticuloendothelial phagocytic function was undertaken in patients with Burkitt's lymphoma in Uganda. The results reveal no difference between the Burkitt patients and controls, with the exception of lower IgM levels among the lymphoma patients. This study provides partial support for the epidemiological evidence incriminating malaria as a co-factor in the aetiology of Burkitt's lymphoma.

Nasopharyngeal carcinoma in Uganda.

Abstract: Review of histologic material seen in Uganda over the 5-year period, 1964–1968, revealed 83 cases of nasopharyngeal carcinoma out of a total of 7,000 malignant tumors. All tumors conformed to the anaplastic type, but those with a small cell structure occurred in older men than those made up of larger cells. The histologic appearances of this tumor were seen but rarely in other sites. In Uganda, tumors occur at a remarkably young age; 25% occur in people under the age of 20 years. The different tribes vary markedly in tumor incidence; Nilotic and Para-Nilotic peoples show a much higher incidence at an earlier age than Bantu or Sudanic groups. The extent to which these differences are due to hereditary and environmental factors is uncertain. It would seem that both will influence the incidence within a given community.

Prostaglandins and Human Reproduction: Physiological Roles and Clinical Uses of Prostaglandins in Relation to Human Reproduction

Abstract: The history of prostaglandins is very closely associated with the human reproductive system. What was described as a smooth muscle stimulating substance found in human seminal fluid (Kurzrok and Lieb, 1930; von Euler, 1934, 1935 and Goldblatt 1933), was later shown to consist of a group of modified long chain 20 carbon fatty acids (see Chapter 9 for the Chemistry of Prostaglandins). Subsequent studies have been directed in three main areas. (1) Towards the isolation and identification of prostaglandins in human reproductive organs and in fluids. (2) Towards a study of the pharmacological actions of these compounds on various reproductive organs. (3) Towards establishing physiological roles for prostaglandins in various reproductive processes.

Lakes of south-western Uganda

Abstract: Summary Lake Bunyonyi was formed about 18,000 years B.P. by a volcanic eruption which blocked a steep-sided valley. Earlier this century fish were introduced into the lake but recently there have been mass fish deaths. Although the thermocline was inconspicuous, density profiles showed the lake to the stratified and chemical evidence suggested stratification was for many years. The water was clear with little plankton and the epilimnioncontained low concentrations of dissolved mineral ions. The hypolimnion was anoxic and had a relatively high mineral ion concentration. The mass fish deaths were attributed to a violent shallow mixing, probably caused by wind, but mixing was insufficient to remineralize the epilimnion.

Intensive chemotherapy in patients with generalized Burkitt's lymphoma.

Abstract: The results of a clinical trial in patients with generalized Burkitt's lymphoma using either multiple doses of cyclophosphamide or a cyclic, sequential regimen employing cylophosphamide, vincristine, methotrexate, and cytosine arabinoside (TRIKE) are reported. Of 42 evaluable patients 24 received cyclophosphamide and 18 received TRIKE. No significant differences were encountered between either group with respect to remission induction, relapse rate or survival. Remission duration was significantly prolonged in the patients receiving cyclophosphamide, but this event has little effect on survival. Although intensive chemotherapy is probably necessary in patients with generalized Burkitt's lymphoma, other variables such as meningeal involvement and immunologic factors appear to affect relapse and survival. Chimiotherapie intensive chez les malades atteints de lymphome de Burkitt generalise Les auteurs communiquent les resultats d'un essai clinique effectue sur des malades atteints de lymphome de Burkitt generalise, pour lequel ils ont utilise des doses multiples de cyclophosphamide ou un traitement sequentiel et cyclique comprenant du cyclophosphamide, de la vincristine, du methotrexate et de la cytosine arabinoside (TRIKE). Sur 42 malades se prětant a l'evaluation, 24 ont recu du cyclophosphamide et 18 le traitement TRIKE. Aucune difference significative n'a ete observee entre les groupes pour ce qui est de l'induction de la remission, du pourcentage de rechutes ou de la survie. La duree de la remission a ete notablement prolongee chez les malades qui ont recu du cyclophosphamide, mais cela n'a eu que peu d'influence sur la survie. Bien qu'une chimiotherapie intensive soit probablement necessaire chez les sujets atteints de lymphome de Burkitt generalise, d'autres variables telles que l'envahissement des meninges et certains facteurs immunologiques semblent influer sur les rechutes et la survie.

The epidemiology and consequences of Schistosoma mansoni infection in West Nile, Uganda. II. Hospital investigation of a sample from the Panyagoro community.

Abstract: A community at Panyagoro in West Nile, Uganda, had already been investigated in the field and shown to be very heavily infected with Schistosoma mansoni A sample of 45 patients from the community was further studied in hospital Their commonest symptoms were abdominal pain and intermittent bloody diarrhoea Many patients were anaemic and had hepatosplenomegaly 22 of the 45 had ascites and 2 had varices of the abdominal wall The ascites was tapped in 5 patients and shown to be a transudate Egg counts for S mansoni were high and for hookworm were very low Liver biopsy specimens commonly showed schistosome eggs, granulomata, pigment and fibrosis, often several of these together, and excluded true cirrhosis and virus hepatitis The observed syndromes and evidence of portal hypertension are therefore probably due in large part to schistosomiasis Taken with the preceding community study, the findings indicate severe disease due to S mansoni in a sub-Saharan African community

Mouthpart sensilla of the tsetse fly and their function. I. Feeding patterns.

Abstract: (1972). Mouthpart sensilla of the tsetse fly and their function. Annals of Tropical Medicine & Parasitology: Vol. 66, No. 4, pp. 525-536.

The Dynamics of Colonial Violence: The Inductive System in Uganda *

Abstract: This article examines the nature and effects of colonial rule implantation at the local level, with specific reference to the case of Colonial Uganda. The general hypothesis is that any agent of change alien to those people whose way of life this agent is to change radically, will use violence as a main means to bring about the change.Linking Galtung's basic distinction between physical, psychological, and structural violence to the three stages in the colonial process of conquest, rule establishment, and maintenance of colonial domination, the author presents concrete examples from the history of Colonial Uganda.It is concluded that a 'successful' change agent would then be one whose aspirations and objec tives merged with those of the people he aspires to change - which is impossible in a colonial set ting, given the very nature of colonialism.

Races of Colletotrichum lindernuthianum and implications for bean breeding in Uganda

Abstract: SUMMARY Nineteen local isolates of the bean anthracnose pathogen have been obtained and tested over the period 1964–70 for pathogenicity on a set of differential cultivars including the sets of four cultivars each used in the alternative systems of Schreiber and Hubberling and of Bannerot and Blondet. The results indicate the existence of a number of races not conforming to those of either system and the ability, when freshly collected, of some isolates with affinities to both α and β races partially to overcome the immunity of the cultivar Cornell 49–242. The implications of the position as now known from these results and a review of the literature for disease-resistance breeding are discussed. Tests of the Uganda isolates, on a range of other dry bean cultivars, indicate a tendency for α and δ races to be pathogenic on small-seeded indeterminate viny or indeterminate bush cultivars, whereas β and γ races tend to be pathogenic on larger-seeded and determinate cultivars.