The development of the system of individual tenure for Africans: with special reference to the Glen Grey Act, c1894-1922
- Authors: Ally, Russell Thomas
- Date: 1985
- Subjects: Cape of Good Hope (South Africa) -- History , Labor policy -- South Africa -- History , Black people -- Employment -- South Africa -- History , South Africa -- Politics and government -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2576 , http://hdl.handle.net/10962/d1003122 , Cape of Good Hope (South Africa) -- History , Labor policy -- South Africa -- History , Black people -- Employment -- South Africa -- History , South Africa -- Politics and government -- History
- Description: The Glen Grey Act was promulgated in August 1894. The main provisions of the Act were for the survey into individual allotments of land held tribally and for a system of local self-government. Described by its originator, C.J. Rhodes, as a 'Bill for Africa, it was first applied to the district of Glen Grey and subsequently extended (in a piece-meal fashion) to a number of districts in the Transkei. The Act was introduced at a crucial stage in South Africa's history. During this period the country stood poised on the threshhold of a significant and far-reaching transformation. The South Africa of 'old', predominantly agricultural and rural was giving way to a 'new' South Africa, modern and industrial. At the centre of this development was the mineral discoveries of the 1860s and 1880s. The period of colonial conquest had also virtually been completed. Most of the hitherto independent African chiefdoms had either been broken up or were under European control. The most urgent problem which now faced the new rulers was devising a policy to govern the millions of black people over whom they had assumed responsibility. Of crucial concern was the creation of working class to minister to the needs of the developing economy. This task was made all the more difficult by the divisions which existed among the ruling groups at the time. To all intents and purposes the country was made up of essentially four independent and autonomous regions. Although the economic changes which were taking place would hasten the unification of the country, until that happened it was well-nigh impossible for a uniform 'native policy' to take shape. The inevitable consequence was the emergence of a number of regional responses to what was essentially a country-wide issue. As the unification of South Africa drew closer however these different regional responses began to vie with each other for supremacy at a national level. The Glen Grey policy then was the response of the Cape to the changes which were taking place in the country. As such, it drew much of its inspiration from the traditions which had developed in the Cape Colony. Its initiators did not however view it as only a regional policy. For them it had applicability to the whole country. It was therefore to be expected that they would attempt to 'sell' their policy to the rest of the country. In the end however it won few adherents outside of the Cape Colony and when Union became an established fact it bowed out to a policy favoured largely by the northern provinces. To be sure the Glen Grey system did linger on for a while in those districts where it had first been applied but it would not be long before it was to fall into official disapproval. While the Glen Grey Act was ushered in with much fanfare and vaunted expectations, its demise was silent and ignominous. The grandiose course which it had charted for the taking-in-hand of the 'native question' came to naught, as did the profound and far-reaching changes which it was believed the policy would inaugurate. The origins of this policy, its implementation and actual working, and the reasons why in the end it foundered and was abandoned will be the main themes of this thesis.
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- Date Issued: 1985
Granitoid related Sn-W mineralisation with special reference to southern Africa, the Variscan Belt in Europe, and the Malay Peninsula
- Authors: Bentley, Philip Nelson
- Date: 1985
- Subjects: Geotectonic settings , Granitoids , Granites , Tin-tungsten , Mineralisation , Greisen environment , Minerals , Exploration
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4908 , http://hdl.handle.net/10962/d1001568
- Description: A review of the geotectonic settings of granitoids and various tin-tungsten provinces in Europe, Malaysia and southern Africa shows a close spatial and temporal association of mineralisation to S-type ilmenite series granitoids. Granitoids with these affinities are derived from crustal anatexis and are most commonly found in continental collision and different ensialic, intraplate orogenic settings, (e.g. SW England, Malaysia, Namibia) as well as in association with anorogenic magmatism (Nigeria, Brazil, South Africa). Tin-tungsten mineralisation is related to late- to post-tectonic granites, emplaced into areas of substantial tectonic thickening. Crustal anatexis leads to an observable calcalkaline chemical trend, with a source of gabbroic or amphibolite composition through anatexis to; mafic-intermediate enclaves, para-autochthonous anatectic granitoids (tonalite, granodiorite), to intermediate level quartz monzonite, granodiorite, biotite-granite, to late-tectonic highly fractionated muscovite-bearing granites, and high level porphyry intrusions. Mineralisation is spatially related to apical protrusions of the youngest most differentiated granite. Various mineralised environments are recognised, including endogranitic veins, primary disseminations, pegmatites and pipes, and exogranitic stockwork and fissure veins, and replacement bodies. A common factor to all these deposits is the inherent greisen environment, characterised by postmagmatic metasomatic alteration and mineral deposition. Common alteration mineral assemblages include albite, quartz, muscovite, tourmaline, and fluorite ∓ topaz. Ore mineral assemblages commonly display a paragenetic sequence of oxides (cassiterite, wolframite, scheelite), followed by sulphides (molybdenite, pyrite, pyrrhotite, chalcopyrite sphalerite, arsenopyrite/loëllingite, Pb-Bi(Ag) sulphosalts) and then lower temperature carbonates (calcite, siderite, ankerite). Analysis of Pan African orogenic provinces in southern Africa (Damara and Saldanian Provinces) shows there is good potential for applying integrated exploration techniques in search of endo-exogreisen Sn-W systems. Careful analysis and interpretation of granitoid geochemistry (K₂0, Na₂0, FeO/Fe₂0₃, F, B, Sn, W, Mo, Cu, Rb, Sr, Ti, Zr) should aid delineation of Sn-W and Mo-Cu metallogenic provinces in these regions. Magnetic susceptibility determinations should also aid distinction of S-type ilmenite series (less than 1 x lO⁻⁴emu/g ) from I-type magnetite series (more than 1 x lO⁻⁴emu/g ) granitoids
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- Date Issued: 1985
A comparative study of acute responses to running in elite black and white marathon athletes
- Authors: Bosch, Andrew Norman
- Date: 1985
- Subjects: Athletics , Sports -- Physiological aspects , Running races , Marathon running , Marathon running -- Physiological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5099 , http://hdl.handle.net/10962/d1001839 , Athletics , Sports -- Physiological aspects , Running races , Marathon running , Marathon running -- Physiological aspects
- Description: Experienced male marathon runners, 9 black and 10 white, with marathon times of 2 hours 45 minutes or faster, acted as subjects for the study, the purpose of which was to determine whether black runners are better suited to marathon running than whites. Body composition was determined by anthropometry. Maximal oxygen uptake (VO₂ max) and other physiological variables were measured during a continuous, speed-incremented treadmill protocol using a computer-aided data acquisition system. Subjects also ran a simulated marathon at 92.5% of the running speed at which the ventilatory threshold (VT) occurred. Physiological, gait and RPE variables were measured at 10 minute intervals during the marathon. Major findings are detailed below:- The VO₂, max averaged 60.4 ∓ 6.5 and 63.2 ∓ 2.9 mI. kg⁻¹.min⁻¹ in the black and white runners respectively and was highly correlated with best marathon race time (r = 0.86 and 0.85 respectively) and VT (r = 0.84 and 0.60 respectively) (p < 0.05). No significant differences existed between the groups in submaximal oxygen uptake (VO₂,) or % VO₂ max utilised at 16 km.hr⁻¹, but the estimated % VO₂ max utilised during a marathon race was higher in the black (89.0 ∓ 5.5%) than the white runners (81. 5 ∓ 3.1%) {p .( 0.05). The % VO₂ max utilised at 16 km.hr⁻¹ (84.8 ∓ 9.1 and 78.6 ∓ 5.8% in the black and white runners respectively) was significantly correlated with the % VO₂, max utilised while racing in the white (81.5 ∓ 3.1%) (r = 0.70) (p < 0.05), but not the black runners (89.0 ∓ 5.5%). The VT occurred at 82.7 ∓ 7.7 and 75.6 :∓ 6.2% VO₂; max in the black and white groups respectively (p < 0.05). Post-marathon blood lactic acid levels were lower in the black (1.30 ∓ 0.26 mmo1.l⁻¹) than the white runners (1.59 ∓ 0.20 mmol.l⁻¹). The respiratory exchange ratio (R) was higher in the blacks than whites when running at 16 km.hr ⁻¹ (1.03 ∓ 0.07 and 0.98 ∓ 0.03 respectively) and during the marathon (p < 0.05). There was no significant difference in pulmonary minute ventilation (Vı) between the groups, but breathing frequency (f) was higher in the black (59 ∓ 12 breaths.min⁻¹) than the white runners (45 ∓ 8 breaths. min⁻¹ ) and tidal volume (V⊤) lower in the black ( 1.33 ∓ 0.16 l.breath⁻¹) than the white runners (1.75 ∓ 0.36 I.breath⁻¹) during submaximal running at 16 km. hr⁻¹ (p < 0.05). The same trend was observed during the marathon run. During the time-course of the marathon f increased and V⊤ decreased In both groups (p < 0.05). Stroke volume decreased and heart rate increased In both groups during the time-course of the marathon (p< 0.05). Cardiac output was therefore maintained. Thermal responses were similar in the two groups. A significant increase in rectal temperature coincided with a decrease in skin temperature and may have been related to an increase in f (r = 0.86 and 0.67 in the blacks and whites respectively), H/R (r = 0.70 and 0.67 respectively) and "local" (leg) RPE (r = 0.84 and 0.82 respectively). It was concluded that black runners were able to run marathon races at a higher % VO₂ more than whites due to the blacks having lower blood lactic acid levels when running at a similar % VO₂ max. Given similar maximal oxygen uptakes, this would enable blacks to run faster. Cardiopulmonary adjustments occur during the time-course of a marathon which maintains Q and Vı
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- Date Issued: 1985
The petrogenesis of the volcanic rocks of the Witwatersrand triad in the Klerksdorp area, Transvaal
- Authors: Bowen, Michael Peter
- Date: 1985
- Subjects: Volcanic rocks , Witwatersrand triad , Klerksdorp , Transvaal , Northwest Province , South Africa , Chemical analysis , Magma , Geology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4909 , http://hdl.handle.net/10962/d1001569
- Description: Several hundred chemical analyses of early Proterozoic lavas of the Witwatersrand triad (incorporating the Dominion Group, Witwatersrand Supergroup and Ventersdorp Supergroup) in the Klerksdorp area, have revealed the presence of various distinct magma types. These essentially correspond to formally defined lithostratigraphic units, but several inconsistencies have necessitated the use of informal nomenclature. The lavas have been regionally metamorphosed to low-grade, greenschist facies assemblages. Original igneous textures are preserved, despite a metamorphic overprint. Metamorphism has resulted in a certain degree of random chemical remobilization. Ba, Sr, Rb, K₂0, Na₂0 and CaO have been highly mobile, and their usefulness in petrogenetic modelling is extremely limited. In contrast, Zr, Nb, Y, LREE's, Cr, Ni, Ti0₂ P₂0₅ and Al₂0₃ have remained immobile. Ti/Zr and Ti/P ratios together constitute efficient discriminating variables for characterizing the different magma types. Lava compositions range from primitive Mg-rich tholeiites to rhyolites, the bulk being tholeiitic andesites. Al₂0₃ contents do not exceed 15%, a feature which reflects the tholeiitic, as opposed to calcalkaline, character of these lavas. Two magma-types are present within the Dominion Group, which is a typical example of bimodal volcanism. The Dominion basic lavas are overlain by the Dominion acid porphyries, with a limited amount of interfingering. The basic lava suite is highly fractionated, with compositions ranging from Mg-, Cr- and Ni-rich tholeiites (close to primary mantle melts) to evolved tholeiitic andesites. The most primitive liquids evolved by 45% fractional crystallization of hornblende, followed by a further 70% crystallization of an orthopyroxene-plagioclase assemblage containing up to 3% sulphides. The Dominion porphyries are rhyolitic, display very limited compositional variation, and probably represent a crustal melt related to the same magmatic event which produced the basic lavas. The only lavas from the Witwatersrand Supergroup present in the Klerksdorp area are those of the Crown Formation (Jeppestown amygdaloid). These are tholeiitic dacites which display extremely limited compositional variation, and are unrelated to any of the other magmas of the Witwatersrand triad. The Ventersdorp Supergroup comprises 4 magma-types: The Kliprivierberg Group lavas at the base are subdivisible into 3 sub-types on the basis of Zr contents. (Zr>11Oppm) are the most evolved. They are tholeiitic andesites which display fairly limited compositional variation. It is likely that more evolved compositions are present in other areas where the porphyritic lavas which characterize this unit are better developed. The overlying Orkney lavas are characterized by 110ppm>Zr>90ppm. They are tholeiitic andesites of similar composition to the Alberton lavas, but have lower incompatible element levels, higher siderophile element levels, and are of extremely uniform composition. The uppermost Loraine/Edenville lavas range from magnesian tholeiites to tholeiitic andesites. They are distinguished by Zr< 90ppm, and contain the most primitive magmas af the Witwatersrand triad, with up to 17,5% MgO, 2600ppm Cr, 600ppm Ni and M-values up to 77. The most primitive liquids evolved by 38% fractional crystallization of orthopyroxene ∓ chromite, followed by 35% fractional crystallization of an extract containing clinopyroxene and plagioclase. The absence of olivine precipitation is a result of the inherently high Si0₂ content of the magma. The Loraine/Edenville, Orkney and Alberton lavas do not lie on a common liquid line of descent, but are probably consanguinous. The Platberg Group overlies the Kliprivierberg Group, and has a coarse-clastic sedimentary unit, the Kameeldoorns Formation, at the base. Three petrographically distinct porphyritic lava sequences overlie the Kameeldoorns Formation, namely the informal "Goedgenoeg formation", the Makwassie quartz-feldspar porphyries and the Rietgat Formation. Despite petrographic differences, the Goedgenoeg and Rietgat lavas are chemically indistinguishable and thus form a single magma-type. The Makwassie porphyries are dacitic in composition with a high proportion of feldspar and quartz phenocrysts. Rational variation trends are attributed to a nett loss of Si0₂ during secondary alteration. The porphyries are probably of crustal origin. The Goedgenoeg/Rietgat lavas display unusual chemistry and a broad, irrational compositional spectrum. They contain very high incompatible element levels, high nonnative quartz, as well as high MgO, M-values, Cr and Ni relative to the other tholeiitic andesites of the Witwatersrand triad. It is tentatively suggested that they are hybrid magmas containing both crust and mantle components, the former possibly represented by the Makwassie porphyries. Field evidence suggests that Platberg volcanism commenced directly after Klipriviersberg volcanism ceased, and was accompanied by a period of enhanced tectonic activity. The Platberg lavas thus probably reflect a crustal melting cycle associated with the Klipriviersberg magmatic event. The Allanridge lavas are the youngest rocks of the Witwatersrand triad. They are separated from the Platberg Group by a unit of flat-lying sediments, the Bothaville Formation, which was deposited after an extended period of peneplanation. The Allanridge lavas form a separate magma-type. They are tholeiitic andesites of similar composition to the Alberton lavas, but have higher incompatible element levels and are not consanguinous. The compositional similarities amongst the basic magma-types of the Witwatersrand triad suggests that all were generated in an hydrous mantle. Interelement ratio differences between the various magma-types nevertheless support the concept that the mantle was chemically heterogeneous during the early Proterozoic.
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- Date Issued: 1985
The geochemical stratigraphy of the volcanic rocks of the Witwatersrand triad in the Klerksdorp area, Transvaal
- Authors: Bowen, Teral Barbara
- Date: 1985 , 2013-03-14
- Subjects: Lava -- South Africa -- Transvaal , Igneous rocks -- South Africa -- Transvaal , Geochemistry -- South Africa -- Transvaal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4932 , http://hdl.handle.net/10962/d1004932 , Lava -- South Africa -- Transvaal , Igneous rocks -- South Africa -- Transvaal , Geochemistry -- South Africa -- Transvaal
- Description: This study lias initiated with the aim of identifying the existence of any geochemical criteria which may be used to distinguish between the various volcanic formations within the Witwatersrand triad. The Witwatersrand triad comprises three sequences: the Dominion Group at the base, the Witwatersrand Supergroup in the middle, and the Ventersdorp Supergroup at the top. It is underlain by Archaean basement rocks, and covered by rocks of the Transvaal sequence. The Dominion Group consists of the sedimentary Rhenosterspruit quartzite Formation at the base, overlain by a bimodal component of the Syferfontein Porphyry succession of lavas. Basaltic lavas are the major component of the Rhenosterhoek Formation, while the overlying Formation consists primarily of dacitic porphyries. Intercalations of one lava type within the other are common, however, so each formation is not the exclusive domain of only one lava type. The Witwatersrand Supergroup, a predominantly argillaceous and arenaceous sequence, contains two narrow volcanic horizons, one of wbich, the Jeppestown Amygdaloid (now Crown Formation), consisting of tholeiitic andesites, occurs in the study area. The overlying Ventersdorp Supergroup has, at its base, the basaltic Klipriviersberg Group, of which four out of six formations are present in the study area, namely, the Alberton, Orkney, Loraine and Edenville Formations. This group is succeeded unconformably by the PIatberg Group, consisting of the sedimentary Kameel doorns Formation, followed by the (informal) Goedgenoeg, Makwassie Quartz Porphyry and Rietgat Formations. The Goedgenoeg and Rietgat Formations are basaltic, whil e the Mawassie rocks range from basaltic to dacitic, the majority being tholeiitic andesites and andesites . The Pniel sequence at the top of the Ventersdorp Supergroup consists of the sedimentary Bothaville Formation, and the Allarridge Formation, the lavas of which are basaltic with some andesitic tendencies. A well-defined geochemical stratigraphy was found to exist. From the eleven volcanic formations examined, nine distinct geochemical units emerged, as the Loraine and Edenville Formations were found to have the same geochemical characteristics, as did the Goedgenoeg and Rietgat Formations. Despite having undergone law-grade greenschist facies metamorphism, very clear variation patterns with height are displayed by the immobile elements Ti, P, Kb, Zr and Y, and the light rare earth elements La, Ce and Nd. In contrast, much scatter was observed in the variation patterns of Na, K, Mn, Ba and Rb. Three techniques were employed to effect discrimination between formations - orthosonal discrimination, interelement and ratio vs ratio plots, and discriminant analysis. Confidence limits placed on normal probability plots served to isolate outlier samples for further examination by the various discrimination techniques. A successful test of the efficacy of the discrimination techniques was afforded when fourteen samples from an unknown succession were positively identified as representative of the Klipriviersberg Group
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- Date Issued: 1985
Spenser's Colin Clout : an introductory study
- Authors: Brown, Molly Anne
- Date: 1985
- Subjects: Spenser, Edmund, 1552?-1599 -- Criticism and interpretation , Faerie Queene , English poetry , Epic , Criticism , Interpretation , Clout, Colin (Fictitious character)
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:2180 , http://hdl.handle.net/10962/d1001831
- Description: From introduction: In the sixth book of The Faerie Qveene, the reader is presented with a vision of the Graces and their attendants dancing on Mount Acidale to the piping of a simple shepherd. Spenser identifies this favoured musician as Colin Clout and then goes on to pose a seemingly inconsequential rhetorical question. "Who knowes not Colin Cloute?” he asks. The note of confident pride which can be discerned in the query clearly reveals Spenser's peculiar interest in one of his most intriguing creations. It is almost impossible to read a representative selection of Spenser's poetical works without noticing the hauntingly frequent appearances of his "Southerne shepheardes boye". Colin appears or is named in no fewer than six of Spenser's poems.
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- Date Issued: 1985
The monitor and synchroniser concepts in the programming language CLANG
- Authors: Chalmers, Alan Gordon
- Date: 1985
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4616 , http://hdl.handle.net/10962/d1006132
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- Date Issued: 1985
The host-searching behaviour of coccophagus atratus compere (Aphalinidae: hymenoptera)
- Authors: Clark, Maxwell Maitland
- Date: 1985
- Subjects: Coccophagus , Hymenoptera , Insects -- Host plants , Insect-plant relationships
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5630 , http://hdl.handle.net/10962/d1004923 , Coccophagus , Hymenoptera , Insects -- Host plants , Insect-plant relationships
- Description: The host-searching behaviour of the parasitoid Coccophagus atratus Compere was investigated. C. atratus parasitoids have unusual host relationships. Female offspring develop in scale insects but male offspring develop hyperparasitically on their conspecific females, or on other parasitoid species. C. atratus females, therefore, must locate, identify and oviposit into two different types of hosts. A primary aim of this thesis, was to identify when and how the behaviour of a female, searching for hosts suitable for female offspring, differed from that of a female searching for hosts suitable for male offspring. This was done by investigating and comparing the behaviour of virgin and mated females. Virgin females can lay only male eggs while mated females can lay both male and female eggs. The role of plant odours and host odours in attracting C. atratus females to the host habitat and to their scale insect hosts was examined with the aid of an olfactometer. Field observations, to test the validity of results obtained in laboratory experiments, indicated that C. atratus females do not search initially for for their hosts' food plants, but search directly for hosts. Only when hosts were physically located did the behaviour of virgin and mated females differ. Recognition cues used by the females to distinguish between the two types of hosts were identified. Finally, the implications of results obtained were discussed in relation to ecological and evolutionary aspects of heteronomous parasitoid biology.
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- Date Issued: 1985
Changes in the image of the feminine from Giotto to Raphael
- Authors: Crossley, Elizabeth Ellen
- Date: 1985
- Subjects: Giotto, 1266?-1337 Feminine beauty (Aesthetics) Women in art
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2471 , http://hdl.handle.net/10962/d1009448
- Description: From Introduction: The ideal of femininity which developed in Renaissance painting, was a visual and psychological type which was to become the Western European Christian formula of the feminine. This type has survived until the present day, so a discussion of its origins can be revealing for us in the twentieth century, especially as it has been neglected in traditional art historical works. In this essay, the changes in the image of the feminine, in just under three hundred years of Florentine painting, starting with Giotto1. and ending with Raphael~· will be covered. The images will be taken from the wo rk of artists who were Florentine in training, who worked in the city or who were strongly influenced by the Florentine style of painting. I have divided the paintings I have studied into three sections. In the Religious section the paintings are mainly of Mary. The Mythological images refer to Greek and Roman myths and the humanistic interpretations of them. Finally, the Portrait and Genre images are selected on the following basis: In the genre paintings they are sometimes part of works related to religion or mythology, but, in their handling, the painters treat the figures as real human beings rather than holy or mythological figures. In others they are bona fide portrait representations. 3. I have made the above distinction because I expect that the gap between religio-mythological images and portraits will give some indication of the difference between the ideal and the reality for women of that time. The images will be analysed and changes noted in favoured types, gestures, expressions, movements, placing in the composition, relationships to others, favoured themes, costume, colour and symbols. I will point out as I proceed the effects that these elements had on the mood and tone of each image.
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- Date Issued: 1985
A novel adjuvant : polymerised serum albumin beads
- Authors: Dewar, John Barr
- Date: 1985
- Subjects: Antigens , Serum albumin
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4104 , http://hdl.handle.net/10962/d1011146 , Antigens , Serum albumin
- Description: Lee, T. et al (1981) proposed the encapsulation of hormones such as progesterone into serum albumin beads, such that their in vivo proteolysis would allow a gradual release of hormone at low levels, for extended hormone action. It was proposed, in the Department of Microbiology, Rhodes University, to replace the hormone component of the above bead formulation, with virus as antigen, in the development of a vaccine. Beads optimally crosslinked at 1% final glutaraldehyde concentration, containing Nodamura virus, were shown to promote an adjuvant effect in vivo, analogous to the release of antigen from Freund's Complete Adjuvant (FCA), so that extended immunostimulation resulted. It was shown that soluble antigen promoted a short-lived primary immune response, peaking around day 25 following inoculation. Antigen presented in beads, on the other hand, initially elicited a low humoral response, but this response gradually increased up to a peak around day 110 post inoculation, before decreasing. No apparent adverse side-effects were noted following inoculation of antigen-containing serum albumin beads, compared to necrosis following antigen in FCA inoculation, supporting the proposal of using albumin homotypic for the test inoculee animal, so that the beads would themselves be non-immunogenic and would merely act as a vehicle in the vaccine formulation. The indirect enzyme-linked immunosorbent assay (ELISA) was used to monitor the humoral response to antigen following inoculation. Results showed that covalent crosslinking of albumin in the formation of the beads did not promote immunogenicity on the part of the chemically altered albumin. The ELISA test was used to indicate the kinetics of the IgG response to Nodamura virus when presented in formulations such as: Freely soluble virus or its subunit; soluble intact virus inactivated by treatment with glutaraldehyde; intact virus entrapped in serum albumin beads cross; linked at different percentage final glutaraldehyde concentrations and also virus subunit prepared in albumin beads. The presence of virus-neutral ising antibodies was noted in serum obtained from rabbits inoculated with virus entrapped in albumin beads. Virus infectivity, titrated in mice, showed protection against virus challenge after incubation of virus with serum obtained above.
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- Date Issued: 1985
Sex ratios of Coccophagus atratus compere (Hymenoptera:Aphelinidae) in relation to host availability
- Authors: Donaldson, John Sydney
- Date: 1985
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5632 , http://hdl.handle.net/10962/d1004933
- Description: The mode of sex determination in most Hymenoptera is that of arrhenotokous parthenogenesis, i.e. females originate from fertilised eggs and males develop parthenogenetically from unfertilised ones. Females can therefore determine the sex of each of their offspring by controlling fertilisation. This has led to much speculation about the factors that govern hymenopteran sex ratios. Many sex ratio theories predict that solitary Hymenoptera should produce male and female offspring in a ratio of 1:1. The limited data available on sex ratios in solitary Hymenoptera does not support this prediction. However, for various reasons, data may not be representative and few detailed studies have been done. The purpose of this study was, therefore, to examine sex ratios of Coccophagus atratus, a solitary hymenopteran parasitoid, to determine whether sex ratios in this species approach 1: 1. C. atratus is a suitable species for sex ratio studies because male and female eggs are deposited in different hosts. The sex of deposited eggs can, therefore, be determined at oviposition. This eliminates any possible effects of differential mortality. Laboratory experiments were designed to determine whether C. atratus females deposit male and female eggs in fixed proportions or in a set sequence. In addition, samples of hosts were collected from the field to assess C. atratus sex ratios under natural conditions. Results show that C. atratus females do not produce sex ratios that approach 1:1 and male and female eggs are not deposited in a set sequence. Sex ratios are variable and appear to be related to the relative abundance of hosts suitable for female development and for male development. These results are discussed in relation to current sex ratio theories.
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- Date Issued: 1985
Computer control of a barry research chirpsounder
- Authors: Evans, Geoffrey Philip
- Date: 1985
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5507 , http://hdl.handle.net/10962/d1007495
- Description: This thesis describes the design and development of a computer-based controller together with additional hardware that greatly extends the capabilities of a Barry Research VOS-1 Chirpsounder. The measurement of the virtual height of the ionosphere as a function of frequency using pulse- and frequency-modulated carrier wave (FMCW techniques is described and the concept of the so called "digital" ionosonde is introduced. The modifications required for the standard Chirpsounder to perform as a versatile digital chirp ionosonde are discussed. Simplified block diagrams are used to describe the Controller hardware which is fully described in two comprehensive service manuals which have been included as appendices. Important aspects of the Controller software and data storage formats are described in detail. The emphasis is then placed on system capabilities. An operators' software manual which describes system initialization and operation in terms of system commands is included as an appendix. Results of tests at both Grahamstown, South Africa , and at the SANAE base in the Antarctic are presented.
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- Date Issued: 1985
The playing characteristics of American trombones and German-system bassoons
- Authors: Galloway, David John
- Date: 1985
- Subjects: Trombone Bassoon
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:2661 , http://hdl.handle.net/10962/d1004508
- Description: Preface: South Africa, a country renowned for its mineral wealth has, perhaps manufacturing paradoxically, no musical wind instrument industry of its own as yet. Thus performers, educators and students alike have either to travel to Europe or America to select an instrument, or to import an expensive instrument that may be both unseen and untried, as very few musical instrument dealers are prepared to outlay capital on stock which appeals to a decided minority of their potential customers. Alternately, a purchase of a particular make or model can be made on the basis of a hearsay opinion; at best, the opportunity for first-hand assessment is minimal. It is the trombone of U. S.A. manufacture and the German bassoon which represent the current state of their respective manufacturing arts, and the yardsticks by which their many imitator's efforts are measured. One of the main aims of this Thesis is to describe in objective terms what has been experienced subjectively over the years of involvement with these instruments -- arguably a task similar to that of the art critic, but operating within more positively defined parameters namely, what works for the student and professional. , and what doesn't. The candidate claims credit for introducing the large-bore Bb/F trombone to South Africa in 1961, following with the introduction of the ·first double-valve bass trombone in 1965, and the first in 1979. The first Schreiber bassoons The advantages and trombone and other bassoon and other such instrument with in-line rotors of the new 5000 series larger-bore was likewise introduced in 1981. pitfalls of " doubling" between the wind instruments , and between the winds, are disc ussed at length in the final section of the Thesis.
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- Date Issued: 1985
Towards a phenomenological model for a critical psychotherapy
- Authors: Gennrich-de Lisle, Peter Hirzel
- Date: 1985
- Subjects: Psychotherapy , Phenomenology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3106 , http://hdl.handle.net/10962/d1004513 , Psychotherapy , Phenomenology
- Description: This thesis aims to establish a model of psychotherapy that is based on experience, but which takes social structure into account. To do this it first sets up a theoretical model of psychotherapy. Thereafter the model is used to analyse four protocols as a way of examining its effectiveness. The analysis of the protocols provides the basis for coming to certain conclusions about the nature of psychotherapy. The theoretical phase first examines the area traditionally known as etiology, but here the approach is from a broadly existential perspective. Thus this section starts by proposing a view of human nature, and then it goes on to say how this nature comes to be disrupted. The influence of the broader social context upon human existence is also considered here. Secondly, there is an attempt to understand how psychotherapy works. Drawing on existential and cultural anthropological material, various themes of psychotherapy are examined, and these are then placed within their social context. Finally, the theoretical phase brings together the themes emerging from the two foregoing sections and integrates them into a single model of "etiology" and "cure". In the following chapter, the adequacy of this model is examined by using it to analyse four protocols written by subjects on their experience of therapy. In the final chapter various conclusions are drawn.
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- Date Issued: 1985
Influence of endogenous female sex-steroids on mutagen metabolism
- Authors: Goold, Richard David
- Date: 1985 , 2013-03-15
- Subjects: Mutagenesis , Drugs -- Metabolism , Steroid hormones -- Receptors , Cytochrome P-450
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3819 , http://hdl.handle.net/10962/d1004919 , Mutagenesis , Drugs -- Metabolism , Steroid hormones -- Receptors , Cytochrome P-450
- Description: Cytochrome P-450, the terminal oxidase of the metabolic mono-oxygenase system, is thought to exist in multiple forms, which have differing substrate specificities, and are variably inducible by different enzyme inducers. Many mutagens, themselves unreactive, require metabolic activation by one or more of these cytochrome P-450-dependent microsomal enzymes for mutagenic activity. Such mutagens may be detected in the Salmonella mutagenicity test only by the incorporation of an hepatic microsomal (59) fraction into the assay (as a first approximation to in vivo metabolism). Induction of the microsomal enzymes by different agents enhances the metabolic activation of mutagens; in fact, many mutagens are only detected when the 59 fraction has been induced by appropriate agents. Inducers of the phenobarbital-type are known to enhance microsomal steroid hydroxylation when administered at supraphysiological levels, inducers of several mono-oxygenase activities. In turn, the steroids, have been reported to be The inductive effects of the female sex-steroids and the combined effects of steroid and phenobarbital (PB) pretreatment on the metabolic activation of four mutagens have been investigated using the Salmonella assay. Female Sprague-Dawley rats were pret reated with 17a-oestradiol (E2) or progesterone (PRG) , at a level of either 1 mg/kg or 20 mg / kg daily for 14 days. A duplicate set of similarly pretreated groups were also induced with PB. Hepatic microsomal fractions were prepared from each group and incubated with each of the te st mutagens in the presence of a tester strain known to detect each particular type of mutagen. Induction of the hepatic metabolizing system by PB increased the activation of the mutagens significantly (as reflected by an increased number of revertant prototrophic S .typhimurium colonies). The administration of PRG also caused significant, and dose-dependent, induction of the activation of af l atoxin B1, benzo(a)pyrene, and dimethylnitrosamine. In general, E2 exhibited no inductive effect, but it did produce an increase in the activation of aflatoxin B1 (a reaction which is known to be catalysed by a mono-oxygenase prefe rentially inducible by PB). When use was made of a microsomal fraction that was prepared from animals which were both steroidpretreated and induced by PB, mutagenic activation was of the same order of magnitude as that observed when induction was brought about by PB alone. The absence of additive effect, taken together with the observations already mentioned, indicate that steroids induce the same cytochrome isozymes that are induced by PB. The implications of sex-hormonal regulation of the metabolic activation of mutagens are briefly discussed. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
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- Date Issued: 1985
The influence of ants on the insect fauna of broad-leaved, savanna trees
- Authors: Grant, Susan
- Date: 1985
- Subjects: Ants -- Behavior , Insects -- Host plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5811 , http://hdl.handle.net/10962/d1006971 , Ants -- Behavior , Insects -- Host plants
- Description: The influence of foraging ants on the insect fauna within the canopy of the tree species Terminalia sericea, Burkea africana and Ochna pulchra was studied in an area of typical South African savanna, over a two year period. The number of individual insects and their species composition was compared on unbanded, ant-infested plants and on banded plants where ants had been excluded. Differences in the level of herbivory recorded on banded and unbanded trees were related to the guild composition of insects within the canopy, and the results are discussed in terms of plant protection as a consequence of ant - insect interactions. Twenty-six ant species were recorded on the study trees at Nylsvley, with individuals belonging to the genus Crematogaster being numerically abundant and dominant within the canopy of each species of tree. These dominant ant species influenced the insect fauna by their strong dependence on honeydew, encouraging a build up in numbers of Homoptera on the branches and leaves of foraged trees, and supporting homopterous populations within the confines of their nest compartments . The exclusion of ants from trees led to fewer "mobile" homopterans (Aphididae, Membracidae, Psyllidae and Cicadellidae) and "sessile" homopterans (mainly Coccidae but also Pseudococcidae). Pyrethrum spraying showed that the guild composition of non-homopterous insects was similar on banded and unbanded trees. Differences in the level of herbivory on banded and unbanded trees suggested that, although slight, foraged trees were protected from some damage by the presence of ant species within the canopy. A trend did exist towards a greater number of insect individuals and species on unbanded trees, and it is postulated that during the period 1982 1984 when drought conditions prevailed over Nylsvley, ants do not reduce insect numbers through predation or disturbance but simply deter phyllophagous feeding. A separate experiment showed that Crematogaster constructor would feed on the eggs and early instar larvae of the saturnid moth, Cirina forda, but low numbers of lepidopterous larvae on the trees may have forced ants to seek honeydew. The negative impact of large homopterous populations on foraged trees was only seen in an isolated field observation where Polyrachis schistacea was found to associate with the lac insect Tachardina sp . . In conclusion it can be said that where homopterans are not the dominant phyllophages, plants do benefit from foraging populations of ants in that damage to the leaves is reduced.
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- Date Issued: 1985
The plea of truth and public benefit as a defence to an action for defamation in South African law
- Authors: Grogan, John
- Date: 1985
- Subjects: Libel and slander -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3708 , http://hdl.handle.net/10962/d1006974
- Description: From introduction: The study begins with a detailed examination of the origins of the defence in Roman law, and traces the dispute over the role of the veritas convicii through the writings of the Roman-Dutch jurists and the decisions of the pre-Union colonial courts in South Africa. The gradual absorption of the requirement of public benefit into the contemporary law is examined. Subsequent sections attempt to extract from the case law and to systematise the rules relating to the requirements of the defence of truth and public benefit, with a view to setting forth the circumstances in which the truth may lawfully be published. Section 2 deals with problems relating to proof of the truth of the imputation; Section 3 with the problem of when publication can be said to serve the public benefit. The final section seeks to examine the juridical basis of the defence and to relate it to recent developments in the law of defamation as a whole. Brief conclusions are then drawn and recommendations made.
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- Date Issued: 1985
Some aspects of the ecological structure of a segmented barrier lagoon system with particular reference to the distribution of fishes
- Authors: Hall, Colin Mark
- Date: 1985
- Subjects: Marine fishes , Aquatic animals , Fish culture , Serpentine
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5633 , http://hdl.handle.net/10962/d1004936 , Marine fishes , Aquatic animals , Fish culture , Serpentine
- Description: The Wilderness lakes system represents a segmented barrier lagoon and comprises three interconnected lakes; Rondevlei, Langvlei and Eilandvlei. The latter is further linked by the Serpentine channel to the Touw river and Wilderness lagoon. The role of these channels, as well as a sluice in the Serpentine, in structuring certain aspects of the ecology of the system was investigated. An analysis of the salt budget of the lakes suggests that the Serpentine dampens tidaI processes to such an extent that they play only a minor role in the overall budget. Furthermore, the channel between Eilandvlei and Langvlei prevents any tidal salt input to the upper lakes. Their estuarine environments are however maintained by salt inputs which occur when the mouth is closed. This unusual phenemenon means that the sluice may have a minimal effect on the salt budget of the system because it is only closed when the mouth of the lagoon is open. Environmental conditions in each of the lakes, the Touw river and Wilderness lagoon were compared in terms of their physico-chemical characteristics and submerged macrophyte communities. A principal components analysis suggests that the physico-chemical environment of each lake is similar. The Touw river however has a very different environment, whilst that of Wilderness lagoon has some similarities to both the lakes and the river. During the study macrophyte communities recovered from a major recession which occurred between 1979 and 1981 . Biomasses in excess of 1000g m⁻² were recorded in both Langvlei and Eilandvlei. In the latter however, macrophyte growth was less prolific than in the former, as some areas of the littoral supported no growth at all. Macrophyte encroachment in the channels is a major factor inhibiting water flow between the lakes. This encroachment is most severe in the Eilandvlei/Langvlei channel where macrophytes covered 80% of the channel's area.The dominant fish fauna throughout the system is composed of a marine/estuarine migratory component. In the lakes the Mugilidae and Sparidae are the most common families, whilst in the lagoon and Touw river predators such as Lichia amia and Argyrosomus hololepidotus also commonly occur. Eilandvlei serves as the initial nursery area for most migratory species. An estimated 52000 fish migrated up the Serpentine towards Eilandvlei during February 1984 . Most fish do not penetrate as far as Langvlei, and this can be related to macrophyte encroachment in the Eilandvlei/Langvlei channel. However, it is argued that should this channel be dredged and the macrophytes removed, the nursery potential of the system would not be greatly enhanced . This is because environmental heterogeneity, in association with an abundance of food in Eilandvlei, make this lake the most attractive nursery area to juvenile marine/estuarine fish.
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- Date Issued: 1985
The effect of sewage on the distribution of seaweed at the Bats Cave east bank sewage outfall in East London, South Africa
- Authors: Klenk, Theodore Charles
- Date: 1985 , 2013-03-13
- Subjects: Marine algae -- Dispersal -- South Africa -- East London , Sewage disposal in the ocean -- South Africa -- East London , Plants -- Effect of sewage on
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4238 , http://hdl.handle.net/10962/d1004768 , Marine algae -- Dispersal -- South Africa -- East London , Sewage disposal in the ocean -- South Africa -- East London , Plants -- Effect of sewage on
- Description: In order to determine which seaweeds were unable to survive in the stressed area and how far the effect of the effluent extended along the coast, various methods were applied and carried out over a two-year period between November 1982 and November 1984. Three major long-term studies took place. The first study was to determine the presence or absence of the seaweeds throughout (1) the entire study area and then (2) in areas broken up into sections with known distances from the outfalls. The second method involved statistical evaluations using point intersect methods and photography to produce information to determine species density, diversity, evenness, and to provide the information required to work with a number of ecological equations in the future. The third method incorporated a long-term survey on cleared plots in various sectors of the study area. The recolonization of the plots was recorded over a thirty-week period. (par. 1.1, p. 6-7)
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- Date Issued: 1985
Teacher-stress in South African state high schools
- Authors: Laughton, Lorraine Rosemary
- Date: 1985
- Subjects: Teachers -- Job stress -- South Africa High school teachers -- South Africa -- Attitudes High school teachers -- South Africa -- Social conditions
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1879 , http://hdl.handle.net/10962/d1005865
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- Date Issued: 1985