Natural Sciences

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Freshwater snail diversity in relation to Schistosomiasis in the middle Zambezi basin in Lusaka Province
(2011-03-31) Mubita, Patricia
This study was carried out at the Middle Zambezi basin in Lusaka province to determine freshwater snail diversity, its relationship to the presence of schistosomiasis and the impact of prevailing environmental factors on snail diversity. The study was carried out during the cool-dry season (July), hot-dry season (October) and hot-wet season (February), from July 2006 to February 2007. Twenty 400 metre transects were established on three rivers, ten streams and one reservoir. Snails were sampled every four metres on each transect using a scoop net. Each transect was divided into five 80 metre segments. Environmental data consisting of physical, chemical and biotic data was obtained at the mid point of every segment. Physical data collected consisted of water depth, temperature and velocity. Chemical data collected consisted of conductivity, pH and calcium concentration. Biological data collected was vegetation by type and genera, and phytoplankton diversity. Fifteen species of freshwater snails were collected from the study area. Pulmonate species consisted of Bulinus globosus, Bulinus forskalli, Bulinus canescens, Biomphalaria pfeifferi, Segmentorbis angustus, Gyraulus costulatus, Lymnaea natalensis, Physa acuta and Ferrissia burnupi burnupi. The prosobranch species consisted of Bellamya cappillata, Cleopatra nsendwensis, Gabbiella kisalensis, Gabbiella sp, Lanistes ovum and Melanoides tuberculata. Linear regression was used to determine the relationship between snail diversity (species richness) and the number of infected children at the schools in close proximity to the water sampling points. There was a significant relationship between snail diversity (in the presence of the intermediate snail host) and schistosomiasis prevalence. Snail diversity explained 62% of the variance in schistosomiasis prevalence. Results of the study demonstrated that in the presence of high species diversity of snails, transmission of Schistosoma haematobhim is lower. Multiple regression analysis (Best Sub Set) revealed that water velocity was the most important factor affecting snail diversity in the rivers, while conductivity was the most important factor in the streams. Snail diversity was significantly different among the different vegetation types. All the floating vegetation types were associated with higher snail diversity whereas Phytoplankton diversity was not significantly associated with snail diversity.
Some reproductive characteristics of Lates stappersII in the Southern part of lake Tanganyika, Zambia
(2011-03-31) Fisamu, Felix Musonda
The following aspects of reproduction of Laics siappcrsii caught in the /amhian sector of Lake Tanganyika were studied: stages of maturity and spawning season: sixes at maturity: sex ratios and fecundity. Fish samples were collected from Septemher. 1999 to February. 2000 This study shows that, the mean gonado-somatic index (GSI) increases from stage I (immature or inactive) to stage IV (ripe-running) in both sexes, and then drops for stage V for females, as a result of release of sexual products. Monthly evolution of proportions of stages of maturity and mean (iSI indicate that spanning was taking place mainly between December. 1999 and February. 2000. The estimated si/es at maturity arc 21.68cm "IT. for males and 24.89cm IT for females and the maturity ranges were 7.68 cm and 11,7'Ocm respectively. The overall sex ratio of 53% females: 47% males for Laics siappcrsii in the /.amhian waters of Lake Tanganyika is not significantly different from the theoretical one. i.e. 50% females: 50% males. This parameter exhibits significant differences among sexes in Januan and February. 2000. and for length classes larger than 32 cm. where females are predominant. Fecundity in Line* siupperxii must be high because of small eggs. Partial fecundiu ranges from 46 000 to 839 000 eggs per fish (average 273 OOOeggs). Relative partial fecundity varies from 441 to 1685 eggs * g-1 o f f i s h (average 914 eggs * g-1 of fish). Lxponenual functions fit better the relationships between total length and partial fecundity (R2 - 0.861). and between body weight and partial fecundity (R2 ~ 0.857). A linear association exists between partial fecundity and gonad weight (R2 - 0.993). There is no correlation between fish sizes (i.e. total length and body weight) and relative partial fecundity. Key words: Laics \iuppersii. /ambian waters of lake Tanganyika, spawning season, si/e at maturity, sex ratios, fecundilv.
Epidemiology of viral gastroenteritis in Children under 5 years at the University Teaching Hospital, Lusaka, Zambia
(2011-03-31) Mpabalwani, Chipandasabo Mwila
The clinical and epidemiological aspects of rotavirus diarrhoea was studied in hospitalized children under five years with acute gastroenteritis in Lusaka, Zambia for a period of one year. Two hundred and fifty six (24.1 %) of 1,064 children admitted to the study were shedding rotavirus. Rotavirus positive rate was higher in children less than one year (37.6 X) and also those less than six months. Rotavirus diarrhoea was seen throughout the year with higher rotavirus positive rate in the cool dry season. In rotavirus positive diarrhoea patients, more children nad dehydration (82.4 X) -than in rotavirus negative group (56.2 %) . In malnourished children rotavirus positive rate was 12.1 % (9 / 71) which was lower than in those with normal nutritional status (29.0 X, 162 / 558). Case fatality rate in the rotavirus positive group was 6.4 X and mortality cases were only seen in children less than 2 years. Enteric adenovirus contributed much less (3.63 X, 6 / 164) to the viral aetiology of acute gastroenteritis and no fatality was noted in this group. This study failed to yield any Small Round Viruses in hospitalised children with acute gastroenteritis.
Evaluation of water pollution in Industrial towns and people's awareness of problems:the case of Kafue river in Zambia
(2011-03-31) Simuuza, Iness
Biology of Lechwe flies MUSCA TEMPESTATUM bezzi with emphasis on the Nutritional requirements as provided by the Lechwe Antelope in Zambia
(2011-03-31) Muntemba, D. C
Studies on the feeding behaviour of Musca tempestatum were carried out in order to investigate the biology of the fly and its relationship to the lechwe antelope. This was done by observing the fly's feeding activities on the antelope and its breeding activities on the lechwe faeces on which it oviposits. The larvae hatch out on the faeces and then migrate into the faeces. This is because, due to crust formation on the surface of the faeces, solidification of faeces and loss of water levels, there is left a small moist space in the middle of the faeces, into which the larvae congregate after making tunnels through which their posterior spiracles are exposed for air. The whole larval stage is accomplished within faeces and therefore larvae depend on faeces for food. The composition of the faeces and their variation was studied in the laboratory so as to investigate the effect of these variations on the survival of M« tempestatum dependent upon lechwe faeces. The detailed readings of moisture and nitrogen percent (dry weight percent of nitrogen) per month are tabulated in the appendices. The results showed that there were variations in the composition of faeces according to the months. This could have been due to seasonal changes in the composition of pasture grasses on which the antelopes feed which could have influenced the composition of faeces directly. Qorrod, (1959); Sen and Butterworth and Arias, (1965) c.f. Greenham, (1972) pointed out that differences in protein and fibre iv content between grass species were much less important than the differences between immature and mature grass of the same species. Sizes and weights of emerged flies reared at different nitrogen percentages were taken to soe whether these were affected by the composition of faeces. Results are shown in the dissertation. Experiments were carried out on the effect of food substances such as sugar, fresh liver and fresh faeces with the combinations of water on the survival of M. tempestatum adults. The flies used for the experiments were collected from the field within faeces in the immature forms, (eggs, larvae, pupae) and then reared in the laboratory. The immature stages of the fly are being described for the first time, other works have shown the behaviour of the adult flies, Patton, (1936). The number of the surviving flies fluctuated between the treatments, with the highest being demonstrated by flies fed on sugar and water and the lowest was found among flies fed on fresh faeces and water. Statistical analyses were done on the numbers of flies remaining alive at the end of the experiments to note whether there were any significant differences between treatments. The results of these experiments indicated that some of the foods given to the flies did not promote or increase survival; which meant that the food qualities obtained from these food substances were used for purposes other than survival (purposes such as reproduction). To this effect further experiments were done in the laboratory to investigate the effect of food quality on reproduction. Crude determinations of nitrogen content in the faeces which were done showed that there were variations which ranged from 2.5% to 6,25$, The highest nitrogen content was taken as a high quality and the lowest as a low quality type of food. The experiments started with varying nitrogen content. The effect of quality was interpreted by the number of eggs laid per larva present initially. It has been shown that M. tempestatum oviposits on fresh lechwe faeces and that the faeces are suitable for oviposition only when they are freshjas soon as there is any crust formation the faeces cease to be attractive to ovipositing female flies. It has also been shown that the flies obtain moisture and food directly from the lechwe and so the flies have to be mobile and capable of following the lechwe from place to place and in this order the relationship is maintained between the two.
Human T-Cell leukaemia virus type 1(HTLV):A prospectus sero-epidemiological study, Lusaka, Zambia
(2011-03-31) Kasolo, Chisaka Francis
HTLV-1 is a retro-virus responsible for pathological disorders such as Tropical Spastic Paraparesis (TSP) and Adult T cell Leukaemia/Lymphoma (ATL). The main characteristic of HTLV-1 infection is its long period of latency and the age related sero-prelavence, especially in endemic areas. A sero-prevalence study of HTLV-1 at the University Teaching Hospital (UTH), Lusaka, Zambia, was done. Two populations namely healthy blood donors and Patients admitted to UTH with pathology thought to be related to HTLV-1 infection were included in this study. The objectives of this study were: 1. To establish the seroprevalence of HTLV-l among blood donors and patients admitted to UTH. 2. To find out whether the presence of HTLV-1 specific antibodies has any relationship with age, sex, HIV infection, Hepatitis B infection or with any particular pathology. Collected sera were tested for HTLV-l specific antibodies by using Particle agglutination test (PA) and Enzyme immuno-sorbent assay (ELISA). Serum positive on at least one test was subjected to a confirmatory Western Blot test, (Fijirebio) A total of 339 Blood donor and 107 patient sera were tested. A total of 26 sera were positive on PA test, 2 were positive on ELISA, and none on Western Blot. Of the sera testing positive on PA, 23 were from the blood donor sera and 3 were from patient sera. On ELISA test one sample each from the blood donor and patient sera was positive. When the 26 PA positive sera were subjected to Western Blot test, 15 were clear negative, 11 were indeterminants and none were positive. The commonest Protein band seen on Western Blot was the gag encoded protein P19. There was no significant relationship between HTLV-1 Indeterminants and HIV positive sera or between HTLV-1 indeterminants and Hepatitis B surface Antigen positive sera. The test method used showed varied specificity and sensitivity. The difference may have been due to a false positive result, arising possibly from high levels of circulating immune complexes commonly associated with frequent parasitic, bacterial and viral infections which are prevalent among populations in the tropics. The absence of specific anti-HTLV-1 antibodies following the use of confirmatory test, may be related to sampling technique employed in this study. On the other hand this could suggest a low prevalence of HTLV-l infection in Zambia as opposed to reports from other African studies. The indeterminant results obtained on Western Blot may support the long latency associated with HTLV-l infection. The indeterminants may be in the process of seroconverting and thus will need to be followed up over a period in order to establish their true status. Cross reactivity with other retroviruses could also be a likely cause of indeterminant results
Assessment of Infestation levels of Chilo partellus swinhoe(Lepidoptera:Crambidae)on maize and the Impact of its parasitoid cotesia flavipes cameron(Hymenoptera:braconidae)in Sinazongwe District of Zambia
(2011-03-31) Moonga, Nzala Miyanda
The spotted stem borer, Chilo partellus (Swinhoe) is one of the most destructive pests of maize in the warm, low altitude regions of Zambia. A study was carried out in Sinazongwe district, which is located at about 600 metres above sea level in the Southern Province to determine the incidence of C. partellus, damage to maize plants and the abundance of its natural enemy, Cotesia flavipes. This study was carried out during the winter cropping seasons of 2005 and 2006 in four locations where previous releases of C. flavipes had been made. The locations described by intensity of C. flavipes released were: locality 1; 500-1000 parasitoids, locality 2; 50,000 parasitoids, locality 3; 100,000 parasitoids and locality 4; non-release. These were classified as low, medium, high and non-release locations respectively. In each location, maize plants were sampled from sixteen farmers' fields at three different growth stages, namely; knee height, tasseling and cob maturity. Ten plants were also randomly collected from each farmer's fields by destructive sampling to assess severity of C. partellus damage. Analysis of variance (ANOVA) was carried out to determine if there were any significant differences across the locations and between plant growth stages. The results showed significant differences (F=7.74; d.f.=3; PO.001) in incidence of C. partellus across the locations. Similar significant differences were also obtained among the three plant growth stages (F=63.59; d.f.=2; PO.001). In addition, significant differences were obtained in respect to the following damage variables; tunnel length (F=12.04; d.f.-3; PO.001), damage index (F=16.39; d.f.=3; PO.001) and number of exit holes (F=100.83; d.f.=3; P<0.001) across the locations. Similarly, significant differences were also obtained at the three plant growth stages in tunnel length (F=115.54; d.f=2; PO.001), damage index (F=12.04; d.f.=2; P<0.001) and number of exit holes (F=7.96; d.f.=2; P<0.001). There were however, no significant differences in leaf damage when a t- test was carried out to compare damage at knee height and tasseling stages across all the locations. Similarly, there were no significant differences in the number of parasitized larvae across the locations and at the three maize growth stages. C. partellus constituted 94.5% and 95.6% of the total stem borer larvae collected from maize plants, and the remaining 5.9% and 4.4% were Sesamia calamistis in the 2005 and 2006 winter cropping seasons, respectively. Results of the present study confirm that C. partellus is the dominant cereal stem borer in Sinazongwe district and clearly show that C. flavipes is fairly well established in this agroecosystem. The results indicate however, that at this level of establishment, C. flavipes did not adequately suppress stem borer populations possibly due to low parasitism levels at peak stem borer incidence. Follow up studies might be necessary to clarify this phenomenon.
Mineralogical and micromorphological characterisation of two soil sequences of the UNZA-FARM(Zambia)
(2011-03-31) Shitumbanuma, Victor
The land has been the ultimate source of nourishment and origin of man and other living organisms. Man has depended and still depends on plants and animals for his survival. These in turn depend on the earth and other organisms. The cultivation of crops has been known to man for a long time, and the use of different techniques to manipulate the soil and plants has resulted in increased crop production. With the increased human population, the demand on the land has increased, and man has to find better and more effective means of utilizing this now scarce resource of soil. Various disciplines of science have studied the soil from different angles, with the ultimate aim of bettering their understanding of it. As the soil is quite a heterogeneous material, its study calls for a combined approach of study. Of the various branches of soil science, a new branch, employing the aid of microscopic and ultramicroscopic techniques has emerged. Micropedology, which aims to search for the processes responsible for the formation of soils as well as specific features both of natural and artificial origin has become an important tool in investigating into the genesis, classification and management of soil. In this study, which was originally meant to cover two soil sequences, a soil sequence has been studied, from a mineralogical and micromorphological view, with the aim of knowing something about its genesis and management properties. Routine physical-chemical analyses, micromorphological and mineralogical analyses were carried out on the soil samples from profiles on the sequence. It was found that there is a colour differentiation along the sequence, due to change in drainage condition. The profiles have been found to have a pellicular to bridged grain surface horizon, overlying illuvial horizons. This kind of microstructure is seen to increase with depth downslope, and this has been attributed partly to the translocation of soil material downslope. Illuviation of clay with free iron and fine organic material has been found to be evident in all the profiles in this sequence. The upper two well drained horizons, have a granular aggregate microstructure in subsurface horizons which gives them a good permeability to water and air. The low land soil, was found to be partly drained and with a higher content of in situ formed nodules. It was found that there was a coincidence between the presence of brown spots in the profile, with the presence of oriented reddish brown clay coatings. The soils have been found to be depleted of most weatherable minerals and to be dominated by resistant, generally nutrient poor mineral grains. Kaolinite is the most dominant clay mineral, with mica, being the other constituent. The silt fraction, shows high amounts of quartz and mica. From the study of heavy minerals and soil thin sections, the parent material show evidence of metamorphic origin, and lateritic origin. The soils have been found to have low CEC and a relatively high amount of iron oxides The presence of the iron oxides, and kaolinite, with micas, has been used to explain the observed low CEC. As regards management properties, it has been found that the low CEC of these soils may be a limitation to good crop yield. The low pH of the upland soils may require application of lime to expect good response from fertilizer application. The low land soils have been found to have a limitation of aeration
An Investigation into the role of Allelopathy in influencing plant diversity around Lantana Camara groves
(2011-03-31) Lwando-Tembo, Catherine
Invasive alien species have become a serious threat to plant biodiversity in many parts of the world. Globally the threat to biodiversity due to invasive alien species is considered second only to that of habitat loss. Invasive species are thus a serious impediment to conservation and sustainable use of global, regional and local biodiversity, with significant undesirable impacts on the goods and services provided by ecosystems. Lantana camara L. is one of the many invasive alien species and has been rated by the IUCN Invasive Species Specialist Group among the world's 100 worst invasive alien species. Zambia's National Biodiversity Strategy and Action Plan of 1998 has identified Lantana camara as one of the introduced invasive plants that negatively impacts on ecosystems and indigenous plant diversity. The overall objective of the study was to investigate L. camara's allelopathic effects on indigenous plants in Zambia. Specific objectives of the study were (i) to determine the effect of L. camara on seed germination of some indigenous plants, (ii) to investigate how L. camara affects growth of seedlings in terms of leaf production, root length, root biomass, shoot length and shoot biomass of Bauhinia petersiana, a woody species that appeared to be negatively influenced by L. camara in the field. The study was conducted in two phases. Phase one involved a field survey to determine whether there was a gradient in indigenous woody plant diversity caused by L. camara invasion and to identify species that appeared to be negatively affected by L. camara. The second phase involved laboratory experiments to determine mechanisms by which L. camara negatively affects B. petersiana seedling growth with regard to leaf production, root length, root biomass, shoot length and shoot biomass . The results in this study showed that L. camara did not necessarily influence plant diversity in its neighborhood. The reasons for L. camara not influencing plant diversity could be that its influence significantly depends on its density and age. It can be assumed that the influence of L. camara occurs at very high density beyond the density of 4 groves per ha at Lilayi Game Ranch where the field survey was conducted. It was also noted that possibly the size of the L. camara groves need to be quite large, beyond the diameter of 4.9 m and 5.3 m for the study groves used in order to have an influence on the floristic diversity at Lilayi Game Ranch study site. The experimental results revealed that germination and seedling growth in terms of leaf production, root biomass, shoot length and shoot biomass of Bauhinia petersiana was reduced by the addition of L. camara leaf and root material to soil which is consistent with results of other studies that have shown that the allelopathic effect of L. camara results in severe reductions in seedling recruitment of nearly all species under its influence. The differences in seedling emergence among the treatments were significant (F = 3.96, p < 0.05) with the Bonferroni all - pairwise comparison test revealing that seedling emergence under the LMT was significantly lower than under the RMT and control but was not significantly different from the LRMT. The findings in this study clearly show that L. camara has allelopathic properties that reduce seed germination and seedling growth in terms of leaf production, root length, shoot length and shoot biomass of B. petersiana. Since L. camara appears to have allelopathic properties that reduce seed germination and seedling growth of some native woody plants, such as B. petersiana, it is therefore recommended that there is prevention of its spread into uninfested areas as this will be the most cost - effective way of conserving indigenous biodiversity. There is also need to use an integrated approach to biodiversity conservation that uses a variety of control methods with a range of methods including herbicides, mechanical removal, fire and biological control. Biological control may not eradicate L. camara but could reduce the plant from a weed to a non-weed status which is then maintained in a steady dynamic equilibrium with the control agent species. In this way, biodiversity may be maintained. In addition, there is need for future studies to consider the effect of L. camara on herbaceous plants and ecosystem functions since these were not considered by the present study.
A contribution to the study of tinea capitis in Lusaka, Zambia
(2011-04-01) Simpanya, Mukoma F.
A study of Enzyme variation and chloroquine sensitivity of plasmodium falciparum in Vitro
(2011-04-01) Lemnge, Moshi Moses Martha
Blood sampler- from children with malaria, were used to set up iri_ vitro cultures of Plasmodium falciparam using fresh human serum to enrich the culture medium. A number of investigation:-; airafid at improving the i_n vitro cultivation t e c h n i q u e ware carried out. Changing culture; medium two times every 24 hours instead of once had n positive effect on the final parasitemia level. Any e f f e c t of extra glucose on parasite growth was not obvious within the two asexual cycles period considered. A number of human sera treated at 56 58 C for 30-45 minutes to Qestrojr complement resulted in a parasitemia twice that obtained with ordinary sera. A further observation on change of so rum was made on a continuous culture which had been maintained in two different human sera for the first 37 days in vitro. The cultures where serum was changed displayed a marked reduction in parasitemia though this was only temporary. However, when heat treated seruir was used no decrease in parasitemia was apparent. S tarch-ge 1-e loc trophoreses ol dirf^r-^nt isolates of P. ralcj^parum fron Zambia revealed enzyme " •=> n i 3 t-j o n in r-i nr o.c" phosphate isornerase ( G P I ) , 6-phospho gluconate denydrogenase ( 6 - P G D ) , and adenosine dean/inase ( A D A ) . Parasite lactato d-.ihydrogens.se (L DH) and peptidase-E (PEP-E) showed no v a r i a t i o n . /- rere enzyme form, 5-PGD-2, was observed at a frequency of 80% but a standard is required to c o n f i rm the e n z y ;-ie typ n , Five different isnlatos of F. fai_c_i.p:aj^urR wci'-e subjected to different low c ore tivt r-at i ons of chloroquina ijri vitro,. Their grovrth was s r c c o s r fully inliibi to d by this drug and they were classifiad as b::ing sensitive. Parasite growth was narkedly reduced after 48 hours of drug administration and completely inhibited by 72 hours although for the last 2U hours culture was in drug-free medium.
Levels of Chlorine and phosphorus containing pesticide residues on selected vegetables in Zambia
(2011-04-01) Inambao, Pauline Manayiwa Tanaye
Tomatoes and cabbage samples were analysed for chlorpyrifos and monocrotophos residues by Gas Chromatography (^GC) vntYv electron capture detector. One field o? tomatoes and cabbage was treated for four weeks at the recommended dose of 0.61/Ha monocrotophos and 21/Ha chlorpyrifos. A second field treated twice in seven days with chlorpyrifos and monocrotophos. A th ird field was not treated at all. The analysis revealed that tomatoes sprayed twice only showed tolerable levels of chlorpyrifos residues while the monocrotophos residues exceeded these levels. No residues were detected after the twenty first day. The residues detected in the cabbage that was sprayed twice only rose to a maximum on the twenty first day after the initial spraying and then decreased to levels above the FAO/WHO Maximum Residue Limits (MRL's). Both tomatoe and cabbage sprayed weekly retained residues with cabbage showing higher levels than tomatoe. The residues detected in the cabbage, sprayed weekly, were as high as 18.268mg/kg for chlorpyrifos and 29.043mg/kg for monocrotophos i.e. well above the recommended FAO/WHO MRL's. Twenty percent of the tomatoe and cabbage samples obtained from the markets were found to have residues exceeding the recommended MRL's. This study also showed that despite the same treatment, tomatoe and cabbage responded differently to chlorpyrifos and monocrotophos and as a result retained their residues in unequal quantities.
Determination of magnesium in dolomite
(2011-04-01) Buumba, Fidelis Maleya M.
In this work, four methods have been tried in an effort to find the best method for the determination of magnesium in dolomite, The determination of the magnesium content of dolomite, the raw material for the production of cement, is very important in that the quality of cement depends on its magnesium content. The methods are: the Classical titration with hydrochloric acid and sodium hydroxide, the Complexometric titration with EDTA, Atomic Absorption Spectrometry and Absorption Spectrophotoraetry with Brio T and Titan yellow. A statistical analysis was carried out using the Student's t-test at 95% level of confidence and the Correlation coefficient. The Student's t-test showed that there is no significant difference between the results by the methods, except those between the Classical titration and Atomic Absorption -Direct Calibration and Absorption Spectrophotometry - Standard Addition methods. The methods also showed good correlation between them except the classical titration and Absorption Spectrometry - Standard Addition which showed poor correlation(r < 0.90). From the results of the statistical analysis and the difficulties encountered during the course of the analyses it has been decided that Atomic Absorption Spectrometry is the best of the four methods for routine quality control analysis.It has been found that it is more sensitive, has fewer interferences and requires the shortest time. However if the cost of an atomic absorption spectrometer is taken into consideration, the method becomes very expensive. In that case the Complexoraetric titration with EDTA is the next best alternative.
Use of Locally available materials in the development of culture media for the production of Cheese starter cultures in Zambia
(2011-04-01) Nkhata, Greyson Lyson Elemson
To determine which farms around Lusaka produce Cheese, a questionnaire was prepared and dispersed to dairy farms affiliated to the Zambia National Farmers Union (ZNFU) around Lusaka.The Dairy Produce Board of Zambia (DPBZ),Pebble Brook Cheese Factory (PBCF) and Kaposhi Cheese Factory (KCF) were visited and modes of cheese processing studied.Lyophilized stock cultures obtained from KCF,ZA de Buxiers BP10 of France and a mother culture from DPBZ were used as principal organisms to test the efficacy and sensitivity of all media used in this study. Eight complex broth media were constructed in the preliminary study. Carbon, nitrogen and growth factors (organic and inorganic)sources varied both quantitatively and qualitatively. Buffering chemicals, distilled water, and sodium chloride were kept constant in amounts of the media dispensed in 250 ml. Pyrex conical flasks cotton wool plugged. They were sterilized by autoclaving (120CC, 15 min, 0.41Kg/cm ) and inoculated with a lyophilized starter culture prior to its activation in pasteurized DPBZ milk. Based on absorbance readings and total colony counts, the quality of media beginning with the optimal was found to be in the following order:MiIk(Mil) —> Soya flour, Orange, Yeast(Soy)—>Whey, Irish potato, Pumpkin (Wip) —> Carrot, Ammonium phosphate (Cap) —> Milk, Glucose (Mig) —>Brown wheat flour, Ammonium phoshate, Sucrose (Bas) —> Meat, Sugarcane, Tomato (Mst) —> Maize bran, Beans,Lettuce (Mbl). Further experiments to estimate the optimal concentrations of ingredients to the growth and propagation of the lactic bacteria were conducted with Mil, Soy, Wip and Cap media.Lactic bacteria cultivated in Mil, Soy and Za de Buxiers BP10 lyophilized culture were activated in skimmed milk and used to produce six samples of Cream cheese at PBCF. The cheese samples were analysed to compare acidity, moisture and fat content at National Council for Scientific Research (NCSR).Significant findings in this study are that local raw materials (milk, soya flour, orange Juice, yeast, whey, irish potatoes, pumpkin leaves, meatbroth, carrot, brown wheat flour, beans and lettuce)can be used to grow and propagate cheese starter cultures. This subculturing technique, when understood and effectively used by the Zambian cheese producers,will help reduce cheese production costs.
Ecological Aspects of rodents at livingstone, Southern province Zambia
(2011-04-01) Chidumayo, Ngulube Emmanuel
Studies of fluke infections in Cattle:special reference to the Enzyme-linked Immunosorbent Assay(ELISA)as a diagnostic tool for bovine fascioliasis and shistosomiasis
(2011-04-01) Ng'ambi, Lily
Studies on fluke infections in cattle with special reference to diagnostic methods were carried out. A suitable diagnostic method was necessary for use to investigate the prevalence and distribution of Fasciola spp. and Scliistosoma sj>p. in cattle The Enzyme-linked Immunosorbent Assay (ELISA), based on the antibody-antigen reaction was developed and standardised for sero-diagnosis of fascioliasis and schistose;,nasis in both experimentally and naturally infected cattle. Using crude adult worm antigen preparation, the ELISA test was able to detect antibodies at four weeks post infection in animals experimentally infected with £. hepa_ti_ca and S>. bovis. This is several weeks earlier than infection could be detected by presence of eggs in the faeces. Moreover the ELISA test was specific for either Fasciola or Schistospma_ infections. There were no cross-reacting antibodies between the two parasites, Samples from an abattoir survey which were naturally infected with _F. gjgantica and ^. mat theej_ were examined by the ELISA test sedimentation technique. The ELISA test detected 47 percent as positive, while sedimentation technique 29 percent. No schistosome egges were detected by sedimentation, but the ELISA test detected antibodies in .48 out of564 samples
Aylalox metabolites in human urine and liver in Zambia
(2011-04-04) Dil, Lee Ann Gage
Aflatoxins are believed by many investigators to play a major role in the etiology of primary hepatocellular carcinoma (PHC). As PHC is the commonest tumour of men in Zambia, investigation of aflatoxin exposure of the Zambian population is warranted. Previous studies in Zambia have shown that aflatoxins are present in certain foods and confirmation of consumption was obtained from a study demonstrating the presence of / aflatoxin metabolites in human urine. /In this study urine samples were collected from patients with and without liver disease admitted to the University Teaching Hospital in Lusaka, in an attempt to examine the possible effect of liver pathology on the type and amount of aflatoxin metabolite(s) excreted. No significant differences were observed. The present study was therefore carried out to investigate this relationship in more depth. Studies have shown that conjugation reactions play an important role in aflatoxin metabolism in animals although the amount and type of aflatoxin conjugates in humans is not known. Thus urine samples, from patients with and without liver disease,were collected for one year and analysed for both free and conjugated aflatoxin metabolites. The incidence of urinary aflatoxin excretion in liver disease and control patients was 3.7 per cent with a mean concentration of 9.1 ng/ 100 ml. Aflatoxins BI , MI and aflatoxicol (AFL) were detected. No significant differences were observed between the two groups of patients although aflatoxins were seen more frequently and at greater concentrations in urine of control patients. This may suggest that patients with liver disease have an impaired ability to metabolize and excrete aflatoxin. IV aflatoxin studies, serum and liver samples were analysed for HBV markers. The HBV carrier state in this study was observed to be exceedingly high: 32 per cent of control patients were shown to have hepatitis B virus surface antigen in their serum. No relationship between the presence of HBV markers, aflatoxin metabolites excreted, and PHC was observed. It was noted, however, that patients excreting aflatoxin also had evidence of HBV infection. A longitudinal, prospective study should now be carried out to investigate the possible interactions of these two factors more closely. VI Glucuronide and sulphate conjugates of aflatoxins MI , PI and AFL were looked for. Surprisingly, no conjugated metabolites were detected, even in patients excreting up to 20 ng of free aflatoxin /100 ml urine. This suggests that these conjugation reactions do not play a major role in aflatoxin metabolism in humans. The urinary survey was extended to a rural hospital in the Eastern Province. Consumption of aflatoxin was observed to be more of a problem there, where urinary aflatoxins were detected significantly more often (incidence = 15.4 per cent) and at greater concentrations (mean = 16.5 ng /100 ml). Liver tissues, taken at autopsy from subjects with and without liver disease, were also examined for aflatoxin metabolites. Only aflatoxin B. was observed, at concentrations of 0.3-9.5 ng/g. Most of the samples were from controls and therefore the effect of liver pathology on the type and/or amount of aflatoxin metabolite(s) observed could not be assessed. However, the liver of one PHC subject was included and was found to contain over 10 times more aflatoxin than the highest level observed in controls. The results of the urinary and liver studies were tabulated according to age, sex and season. Aflatoxin was detected significantly more often (P <0.05) in livers obtained from males than females and, in Lusaka, only urine samples collected from males were positive for aflatoxin. It was found that the likelihood of consuming aflatoxin was significantly higher in the rainy season than the dry season (P <0.05). It is generally believed that both aflatoxin and hepatitis B virus (HBV) influence the incidence of PHC. Therefore, concurrent with
Concertration and toxicity levels of heavy metal pollutants in soils and vegetation in kitwe (Copperbelt),Zambia
(2011-04-04) Lupupa, LLoyd
In Zambia, mining of minerals is concentrated in the Copperbelt province. This and other industries of the area has brought about environmental degradation through release of possible unwanted toxic substances. The purpose of this study was to obtain the concentration of heavy metal pollutants, and determine the extent of pollution in the city of Kitwe. Zambia. Cadmium, Cobalt, Copper, Lead and Zinc were investigated up to 20km away from the Nkana smelter in three directions; North-west, West and Southeast. High concentrations of metals were detected in soils and plants near the smelter and show inverse relationship with distance from the smelter. The results ranged between 0.7 to 43mg Co/kg, 6.6 to 5300mg Cu/kg, 1.4 to 30.5mg Pb/kg, 0.5 to 76.5mg Zn/kg in soils and 4.3 to 94.5mg Co/kg, 7.6 to 2330mg Cu/kg and 22.2 to 175mg Zn/kg dry matter in plants. The results were trace for lead in plant samples and trace for cadmium in both soil and plant samples.
Spectroscopic studies-Cyclopentadienyl iron dicarbonyl ketone complexes
(2011-04-04) Phiri, LLoyd
This dissertation is focused on the spectroscopic characterization of cyclopentadienyl iron dicarbonyl ketone complexes 42. The ketone silver tetraflouroborate complexes 32 are initially prepared. The formation of 32 is supported by the enhanced solubility of the silver tetraflouroborate salt in the ketone dichloromethane solution and the infrared shifts of the ketone carbonyl bands to lower wavenumbers. The ketone silver tetrafluoroborate 32 are reacted with cyclopentadienyl iron dicarbonyl iodide to produce cyclopentadienyl iron dicarbonyl ketone complexes 42. These complexes (42) are characterised by infrared (IR), proton and carbon- 13- nuclear magnetic resonance ('H/13CNMR) spectroscopies. The infrared shifts of carbonyl bands to lower wavenumbers is observed in 42. Carbon- 13 -nuclear magnetic resonance (13CNMR) of cyclopentadienyl iron dicarbonyl cyclopentanone 42vi also compares very well with cyclopentadienyl iron dicarbonyl complexes prepared by Ganson. The two terminal carbonyls of 42vi are less by A6 2.2 from Gansons range of521 1.4 - 216.2. The two terminal carbonyls of 42vi appear at£209.2. ass spectroscopy further shows cyclopentadienyl iron dicarbonyl ketone cation, i.e 49, as a dorminant dissociation product.
Nucleophilic displacement reactions of some carbohydrates in dimethyl sulphoxide
(2011-04-04) Muyobela, Mwamba T. Benny
Several 5-0-toluene-p-sulphonyl and 5-iodo derivatives of «-and 3-ribofuranoses and «-xylofuranose have been prepared in order to study their reactions with sodium hydrogen carbonate in dimethyl sulphoxide. Similar reactions are known to convert acylic primary sulphonates and iodides to aldehydes but the sugar derivatives were observed to yield different products. Detosylation of the sugars to give the corresponding alcohols was the most usual outcome but in two instances the tosyloxy and iodo groups were ejected to give an anhydro sugar and a rearranged product respectively. The mechanisms of these reactions are considered. Reaction of a ribofuranose primary sulphonate with the anion of dimethyl sulphoxide led to base-induced elimination of toluene-p-sulphonic acid rather than nucleophilic substitution. The results of the work are presented within the context of possible approaches to converting pentoses into hexoses by way of chain extension reactions at the C-5 carbon atom of pentofuranoses.

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