ABSTRACT Aspects of the feeding strategies and digestive invertebrate-microbial interactions of two saltmarsh thalassinid detritivores, the mudprawn Upogebia africana (Ortmann) and the sandprawn Callianassa kraussi Stebbing were examined. Resources available in their respective habitats were investigated together with the feeding apparatus, diet and digestive enzymes necessary for hydrolysis of refractory compounds of detritus. U. africana inhabits the upper reaches of Langebaan lagoon (Geel...
Abstract Cycloadditions of steroidal 14,16-dienes with ketene equivalents were investigated, as routes to estradiol and estriol analogues. The cycloadduct of 3-methoxyestra- 1,3,5(10), 14,16-pentaen-17-yl acetate and 2-chloroacrylonitrile underwent an unprecedented tandem rearrangement, on attempted alkaline hydrolysis to the corresponding ketone. This product, obtained in ca. 90% yield, was formulated as (161R)-3-methoxy-17-oxo-158,161-cyclo-14,168-ethano-148-estra-1,3,5(10)-triene-16L carbo...
ABSTRACT The poor response of some plant species, e.g. wheat, to ammonium nutrition has been attributed to a diversion of carbon allocation from structural material for root extension to functions associated with the assimilation and translocation of ammonium in the root. The aim of this research was to investigate carbon allocation in response to ammonium or nitrate nutrition in wheat, an ammonium intolerant species, and maize, which exhibits ammonium tolerance. Experiments were · carried ...
Abstract The structures of some non-cellulosic S-Q-Glycans from three plant sources have been investigated and each was found to be characterised by linked D-pyranosyl a main chain consisting of S-(1-44)- sugars. The polysaccharides were, however, different in structural features in a manner apparently related to their respective locations within the organs of the plants concerned. The polysaccharides were isolated and purified using standard fractionation methods including chromatographic te...
ABSTRACT A regional study of highly metamorphosed supracrustal rocks was undertaken in the western portions of the Namaqualand Metamorphic Complex. The study area was essentially restricted to a north - south section some 50 kilometres wide and 220 kilometres long . Eight east-west-trending belts of supracrustal rocks were examined, together with several smaller paragneiss remnants , in an area dominated by quartzo - feldspathic gneisses of granitic composition. The supracrustal rocks were c...
Abstract The seed that eventually gave birth to this thesis was planted in August, 1975 when, during a cruise of the Research Vessel Meiring Naude the existence of deep-sea cyclonic vortices in the South Western Indian Ocean was discovered. Little was it realised during that small, fortuitous beginning in 1975 that the study would develop into the first detailed physical oceanographic investigation of the Mozambique Ridge and adjacent Mozambique Basin areas. It could also not be foreseen tha...
Abstract. A brief review of the literature on the effects of nitrate and ammonium nitrogen sources on plant growth, and the assimilation of those nitrogen sources, has been presented. A water culture technique for the growth of maize was developed. The use of a gravel rooting medium with nutrients recycling through the rooting medium, and an iron supplement in the form of ferric citrate, resulted in superior growth of nitrate-fed plants in comparison to that observed with a hydroponic growth...
Abstract This thesis consists of two chapters, of which the first presents a categorial study of the concept of initiality (also known as projective generation) and the second gives applications in the.theory of uniform and quasi-uniform spaces, The' first three sections of chapter 1 expound basic aspects of initiality, such as its relation to categorial limits and to embeddings, the· latter being defined with respect to a faithful functor to a bicategory. The notion of a separated object wi...
Thesis on A Study Of Oil Bearing Seeds From Some Indigenous Plants. The everyday use of fats and oils can roughly be divided into the following two classes. Firstly, they are one of the basic ingredients) directly and indirectly, in the diet of the, human being. .Secondly, they are used for soap-making, for the manufacture of paints and other drying vehicles, and also for making greases and other miscellaneous, industrial products. For each purpose a different type ·of oil is needed, so tha...
ABSTRACT Africa green monkeys (AGMs, Chlorocebus aethiops) (Gray, 1870) and olive baboons (Papio anubis anubis) (Lesson, 1827) are common non-human primates (NHPs) found within major urban centres in Kenya. The widely distributed AGMs are naturally infected with simian immunodeficiency virus (SIV) of the genus Lentivirus. While a baboon specific SIV has not been reported so far, studies have demonstrated that baboons are non-receptive to SIV infection leading to low prevalence in these speci...
ABSTRACT Agrochemical industries are faced with inadequate supply of molasses that is the main raw material for ethanol production creating a need to develop an alternative feedstock. The use of sweet sorghum will alleviate the problem. Three sweet sorghum (Sorghum bicolor L. Moench) genotypes, EUSS10, EUSS11, and EUSS17 were tested against five controls, SS21, SS17, SS14, ACFC003/12 and SS04 to evaluate their ethanol yield potential, stability, and adaptability in Busia, Siaya and Kisumu Cou...
ABSTRACT A sampling design that provides estimates of population mean and abundance with small variance is important to researchers. Estimates that are accurate even with minimal sampling efforts allow researchers to easily and confidently investigate rare populations. In the determination of efficient sampling design for rare and clustered population, mean square errors have been applied in many previous research works. However, this method only captures the variability of the estimator and...
Abstract rviodel reconstruction using photoconsistency refers to a method that creates a photohull, an approximate computer model, using multiple calibrated camera views of an object. The term photoconsistency refers to the concept that is used to calculate the photohull from the camera views. A computer model surface is considered photoconsistent if the appearance of that surface agrees with the appearance of the surface of the real world object from all camera viewpoints. This thesis pres...
Abstract This project focussed on the investigation, development and evaluation of a closed loop control system on a rougher flotation cell that could improve PGM flotation performance. A PGM rougher flotation cell equipped with Online Stream Analysis (OSA) and machine vision system (SmartFroth) was used during the investigation. Online measurements included bubble velocity, average bubble area, bubble colour; Pt, Ni and Cu concentrate grade and concentrate flow rate and density. Air additio...
ABSTRACT An infant’s anthropometry (weight and length) at birth are important public health indicators for its survival and later development. Low birth weight (LBW) and stunting at birth are among the major causes of infant mortality which is still a worldwide problem. Despite the government’s effort to improve healthcare services, LBW is still a problem at the Provincial General Hospital (PGH) maternity, Nakuru. The main objective of this study was therefore to determine the relationshi...