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Inkwenkwe endala

- Nonogcinile, Nomillion and group, Tracey, Andrew T N and Gerhard Kubik

Inobane

- Nawaileti, Tracey, Andrew T N

Interactions between fig wasps and their host figs

- Nefdt, Rory John Charlton

  • Authors: Nefdt, Rory John Charlton
  • Date: 1990
  • Subjects: Wasps , Mutualism (Biology)
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5718 , http://hdl.handle.net/10962/d1005404 , Wasps , Mutualism (Biology)
  • Description: Fig trees (Ficus spp.) and fig wasps (Hymenoptera: Agaonidae) are partners in an intimate mutualism. The trees provide ovules in which wasp larvae develop while the wasps pollinate the flowers and are therefore indispensible for fig seed production. Agaonid fig wasps oviposit down the styles of fig flowers and it has generally been accepted that they were unable to reach the ovules of "long" styled flowers , which would produce seeds, thus maintaining an evolutionary stable mutualism. African fig species were found to have unimodal style length frequencies, with no separation into long and short styled flowers. In several species the ovipositors of their associated agaonids were long enough to reach the majority of ovules. The number of foundress agaonids entering a fig influenced fig seed set and therefore was an important factor regulating the proportion of flowers producing seeds or pollinators. In the two Ficus species that were studied, entry of more than three agaonid foundresses into one fig resulted in competition for limited oviposition sites and less female - biased offspring sex ratios. It is hypothesised that sequential laying of male eggs followed by female eggs, under variable oviposition site limitation, results in sex ratio adjustment, as predicted by local mate competition theory. Evidence in support of this hypothesis is presented. A number of non - pollinating torymid and pteromalid fig wasps also oviposit into each fig species. The sycophagines and sycoecines oviposit down the styles from inside the fig inflorescences like their agaonid counterparts, while other species insert their ovipositors through the wall of the fig from the outside. Like the agaonids, sycophagines were characterised by being pro - ovigenic, with numerous fully developed eggs at emergence. Sycoecines were able to re - emerge from figs they had oviposited in and lay their eggs in more than one fig. They had short ovipositors, allowing access to a smaller proportion of flowers than agaonids or sycophagines. Externally ovipositing fig wasps were syn-ovigenic, able to develop eggs as adults and invested more energy and time during each oviposition event. Differences in the ovipositor lengths of these species did not segregate their oviposition sites spatially, and therefore does not reduce competition between species. Attack by parasitoids and inquiline fig wasps from the exterior did not constitute a selection pressure against agaonids ovipositing in ovules closer to the periphery of the fig's surface, as predicted by Michaloud's enemy-free-space hypothes is. It cannot therefore explain the preference shown by ovipositing agaonids for shorter styled flowers.
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  • Date Issued: 1990

Interrupt-generating active data objects

- Clayton, Peter Graham

  • Authors: Clayton, Peter Graham
  • Date: 1990
  • Subjects: Parallel programming (Computer science) Electronic data processing -- Distributed processing
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4677 , http://hdl.handle.net/10962/d1006700
  • Description: An investigation is presented into an interrupt-generating object model which is designed to reduce the effort of programming distributed memory multicomputer networks. The object model is aimed at the natural modelling of problem domains in which a number of concurrent entities interrupt one another as they lay claim to shared resources. The proposed computational model provides for the safe encapsulation of shared data, and incorporates inherent arbitration for simultaneous access to the data. It supplies a predicate triggering mechanism for use in conditional synchronization and as an alternative mechanism to polling. Linguistic support for the proposal requires a novel form of control structure which is able to interface sensibly with interrupt-generating active data objects. The thesis presents the proposal as an elemental language structure, with axiomatic guarantees which enforce safety properties and aid in program proving. The established theory of CSP is used to reason about the object model and its interface. An overview is presented of a programming language called HUL, whose semantics reflect the proposed computational model. Using the syntax of HUL, the application of the interrupt-generating active data object is illustrated. A range of standard concurrent problems is presented to demonstrate the properties of the interrupt-generating computational model. Furthermore, the thesis discusses implementation considerations which enable the model to be mapped precisely onto multicomputer networks, and which sustain the abstract programming level provided by the interrupt-generating active data object in the wider programming structures of HUL.
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  • Date Issued: 1990

Isolation of and interaction of nutrients with the linoleoyl-coa desaturase complex

- Perkins, Denise Mary

  • Authors: Perkins, Denise Mary
  • Date: 1990
  • Subjects: Cell proliferation , Cancer cells -- Growth -- Regulation , Enzymes -- Purification
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4558 , http://hdl.handle.net/10962/d1018264
  • Description: The termina1 enzyme in the linoleoyl-CoA desaturase enzyme complex, delta-6-desaturase was implied in the control of cell proliferation in cancer cells. One of the aims of this study was to isolate the terminal enzyme. It was decided that in order to isolate this enzyme it was first necessary to isolate the entire complex and then to enzymatically solubilise the first two components of the complex i e cytochrome b5 reductase and cytochrome b5 from the complex resulting in a pure delta-6-desaturase . The first two components were isolated and purified using simplified and easily reproducible methodologies which could be utilised in the final purification of delta-6- desaturase. The entire enzyme complex, linoleoyl-CoA desaturase was also isolated in a pure form and this pure complex was used to attempt to isolate delta-6-desaturase. The terminal enzyme was isolated with some cytochrome b5 still bound to it. The methods used had proven to be successful and with some modifications should yield a pure enzyme. Zinc and GLA were known to play a role in the inhibition of cancer cell proliferation and zinc was hypothesised to inhibit cell growth by stimulating the activity of the linoleoyl-CoA desaturase enzyme complex which is involved in the regulation of cell proliferation. GLA is the product of the reaction that this enzyme complex catalyses and GLA has been shown to inhibit cancer ce ll growth. The effect of GLA on cell growth and linoleoyl-CoA desaturase activity was thus investigated. Results showed that both zinc and GLA inhibited cell growth and that the combined addition of zinc and GLA generally resulted in the inhibition of cell growth and the activation of linoleoyl-CoA desaturase activity in the BL-6 cells while having a less pronounced effect on the LLCMK cells. The results of this study support the hypothesis that zinc may be a cofactor of linoleoyl-CoA desaturase.
  • Full Text:
  • Date Issued: 1990

Kachere ntombwe

- Saini Kamoya, Tracey, Andrew T N

Kalota kudya nkululu, teteruka

- Saini Kamoya, Tracey, Andrew T N

Kamba wakwira moto

- Kambazite Makorekore, Mang'anja men, Tracey, Andrew T N

Karikongwe

- Kambazite Makorekore, Mang'anja men, Tracey, Andrew T N

Karikongwe

- Kambazite Makorekore, Mang'anja men, Tracey, Andrew T N

Keorapetse Kgositsile, When the Clouds Clear. Johannesburg: Congress of South African Writers, 1990. Book Review

- Klopper, Dirk

  • Authors: Klopper, Dirk
  • Date: 1990
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/460796 , vital:76036 , https://journals.co.za/doi/epdf/10.10520/AJA00284459_194
  • Description: New Coin is one of South Africa's most established and influential poetry journals. It publishes poetry, and poetry-related reviews, commentary and interviews. New Coin places a particular emphasis on evolving forms and experimental use of the English language in poetry in the South African context. In this sense it has traced the most exciting trends and currents in contemporary poetry in South Africa for a decade of more. The journal is published twice a year in June and December by the Institute for the Study of English in Africa (ISEA), Rhodes University.
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  • Date Issued: 1990

Kowa wadodoma

- Kambazite Makorekore, Mang'anja men, Tracey, Andrew T N

Lady's Slippers Rock, Witteklip Mt., Port Elizabeth

- Vanderplank, Helen J

Latshon'ilanga

- Ngqoko married women villagers, Tracey, Andrew T N

Lesego Rampolokeng, Horns for Hondo. Fordsburg Congress of South African Writers, 1990. Book Review

- Doherty, Christo

  • Authors: Doherty, Christo
  • Date: 1990
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/460538 , vital:75946 , https://journals.co.za/doi/epdf/10.10520/AJA00284459_183
  • Description: New Coin is one of South Africa's most established and influential poetry journals. It publishes poetry, and poetry-related reviews, commentary and interviews. New Coin places a particular emphasis on evolving forms and experimental use of the English language in poetry in the South African context. In this sense it has traced the most exciting trends and currents in contemporary poetry in South Africa for a decade of more. The journal is published twice a year in June and December by the Institute for the Study of English in Africa (ISEA), Rhodes University.
  • Full Text:
  • Date Issued: 1990

Lewasi ndijarabasu

- Kambazite Makorekore, Three other players, Tracey, Andrew T N

Marikebo

- Kambazite Makorekore, Mang'anja men, Tracey, Andrew T N

Mbariko

- Z. Chimozi, Tracey, Andrew T N

Mdledle's Xhosa translation of Julius Caesar

- Mtuze, Peter T

  • Authors: Mtuze, Peter T
  • Date: 1990
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/457804 , vital:75680 , https://hdl.handle.net/10520/AJA1011582X_184
  • Description: Although Xhosa literature could not escape the influence of Western literature over the decades, only a handful of literary works has been translated into Xhosa. Tiyo Soga's pioneering translation of Bunyan's Pilgrim's Progress, Uhambo lomhambi, appeared in 1867. Bunyan's book was either translated, adapted or parodied by most of the emerg-ing African literatures in South Africa. Then followed a long wait until 1947, when SEK Mqhayi translated GB Hobson's Kees van die Kalaha-ri as Adonisi wasentlango. As was the case with other African lan-guages, the'50s and early'60s saw the hey-day of translations into Eng-lish. Booker Washington's Up from Slavery was translated as Uku-phakama ukusuka ebukhobokeni by IIR Iolobe in 1951, while the first of BB Mdlede's translations of Shakespeare, UJulius Caesar, appeared in 1957, along with Iolobe's translation of W. Bonsel's Maja die bei (UMa-ya: Amahla-ndinyuka enyosl) and D. Lupuwana's translation of Khwane by P. Cook.
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  • Date Issued: 1990

Metalworkers prepare to Fight for a Living Wage

- NUMSA

  • Authors: NUMSA
  • Date: 1990
  • Subjects: NUMSA
  • Language: English
  • Type: text
  • Identifier: http://hdl.handle.net/10962/110675 , vital:33321
  • Description: The NUMSA 1990 Living Wage Campaign is starting to move. After a slow start NUMSA members are gearing up for the big fight. We are going through big changes in South Africa. We want to tell the bosses and De Klerk: the workers will never end the struggle lor a Living Wage, jobs for all, houses for all, proper health care for all. De Klerk must meet our demands. We want to end the system that gives the bosses freedom to exploit workers. Our battle cry this year is: Our Industry, Our Country, Forward to Workers' Control. In February this year NUMSA/Es National Bargaining Conference set-out the workers demand.
  • Full Text:
  • Date Issued: 1990
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