List of Titles

Potential pollinators of the Cape Group of Crotalarieae (sensu Polhill)(Fabales: Papilionaceae), with implications for seed production in cultivated rooibos tea

- Gess, Sarah K, Gess, Friedrich W

Authors: Gess, Sarah K , Gess, Friedrich W
Date: 1994
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/452372 , vital:75123 , https://hdl.handle.net/10520/AJA10213589_414
Description: This study characterizes the assemblages of Hymenoptera that visit flowers of the genera Aspalathus Linnaeus, Lebeckia Thunberg, Wiborgia Thunberg and Rafnia Thunberg, the Cape Group of Crotalarieae (sensu Polhill1981) (Papilionaceae) , and evaluates the potential of their members as pollinators. All the assemblages from the western and eastern Cape are characterized by the presence of Megachilinae (Megachilidae) and Xylocopinae and/or Anthophorinae (Anthophoridae), and those from the west (excluding Rafnia) by the presence of Masarinae (Vespidae). Although not restricted to Polhill's Cape Group, the Megachilinae and Xylocopinae are potential pollinators. Two species of Masarina Richards (Masarinae) are apparently restricted to Aspalathus, Lebeckia and Wiborgia, and are potential pollinators of the smaller-flowered species of these genera. Two species of Ceramius Latreille (Masarinae) are apparently restricted to Aspalathus and are potential pollinators and, within their distribution ranges, the most dependable visitors of this genus. Apis mellifera Linnaeus (Apidae) and Eumeninae (Vespidae) visit all four genera but are probably of little importance as pollinators. Apis mellifera is certainly able to obtain nectar from the smaller-flowered species without tripping the flowers. The implications of these findings for seed production in the rooibos tea industry are discussed.
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Date Issued: 1994

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Redox reactions of an Mo (V) tetrasulfophthalocyanine

- Ferraudi, Guillermo, Nyokong, Tebello, Feliz, Mario, Perkovic, Marc, Rillema, D Paul

Authors: Ferraudi, Guillermo , Nyokong, Tebello , Feliz, Mario , Perkovic, Marc , Rillema, D Paul
Date: 1994
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/295530 , vital:57351 , xlink:href="https://doi.org/10.1016/0020-1693(93)03664-V"
Description: The preparation of an Mo(V) tetrasulfophthalocyanine and some of its thermal and photochemical reactions have been investigated in this work. Electrochemical processes have been followed by means of the UVVis spectral changes and compared with those observed in flash photolysis. Mo(IV) and Mo(V)-ligand-radical species are common intermediates of the electrochemical and photochemical reactions. In 254 nm irradiations of the Mo(V) tetrasulfophthalocyanine in aqueous solutions of 2-propanol, the macrocycle can be photohydrogenated and the product of the photolysis can be reoxidized with O2 back to the parent complex.
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Date Issued: 1994

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Research priorities for environmental education in southern Africa: Preliminary report

- Janse van Rensburg, Eureta

Authors: Janse van Rensburg, Eureta
Date: 1994
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/438781 , vital:73499 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137480"
Description: In this preliminary research report I introduce initial interpretations of the results of a recently completed study on research priorities in southern Africa. The study has been sponsored by Murray and Roberts, Rhodes University and the HNRE (Human and Natural Resources in the Environment) Programme of the Human Sciences Research Council.
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Date Issued: 1994

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Resolving ambiguous results of host-specificity tests the case of two Leptinotarsa species (Coleoptera: Chrysomelidae) for biological control of Solanum elaeagnifolium Cavanilles (Solanaceae) in South Africa

- Olckers, T, Hulley, Patrick E

Authors: Olckers, T , Hulley, Patrick E
Date: 1994
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/452358 , vital:75122 , https://hdl.handle.net/10520/AJA10213589_421
Description: Two leaf-feeding chrysomelids from North America, Leptinotarsa texana (Schaeffer) and Leptinotarsa defecta (Stal), are promising candidates for the biological control of Solanum elaeagnifolium Cavanilles (Solanaceae) in South Africa. Permission for release was delayed because the beetles fed on cultivated eggplant (Solanum melongena Linnaeus) under cage conditions. After considerable deliberation and further investigation, it was concluded that the results of the cage tests had been overemphasized. The beetles were cleared for release in South Africa on the following grounds: (i) neither Leptinotarsa species attacks eggplant in their native North American habitats; (ii) in South Africa, many insect herbivores of Solanaceae feed on eggplant in cultivation but cause minor damage relative to cosmopolitan polyphagous pests; (iii) as with L. texana and L. defecta, Conchyloctenia tigrina Olivier, a South African chrysomelid that also occurs on eggplant in cultivation, fed on eggplant in indoor cages, but preferred its natural Solanum hosts in large outdoor cages; (iv) eggplant cultivation methods include crop rotation and severe pesticide regimes, which should exclude Leptinotarsa along with the other insects.
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Date Issued: 1994

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Social transformation in response to the environment crisis: The role of education and research

- van Rensburg, Eureta J

Authors: van Rensburg, Eureta J
Date: 1994
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/450146 , vital:74886 , https://www.cambridge.org/core/journals/australian-journal-of-environmental-education/article/abs/social-transformation-in-response-to-the-environment-crisis-the-role-of-education-and-research/F8B2980AEC1FC8F763E68981373AFB1C
Description: In this paper I examine two activities which are often attributed with a role to play in social transformation, namely environmental education and research, for their potential to contribute to collective change. I do so by drawing on the results of a recent empirical study in southern Africa, in which I distinguished four orientations to research in/and environmental education. In exploring the transformatory roles of research and environmental education, as conceptualised in these four orientations, I conclude that the most prevalent orientations reveal modernistic assumptions which limit their potential to contribute to social transformation.The decision to interpret the results by focusing on social transformation grew out of what I regarded as the most significant dimensions of the context of the study. These are the global and regional calls for social transformation in response to the environment crisis, the dramatic political changes in parts of southern Africa, the need to improve education in the region, and finally, less obvious global epistemological shifts in the conceptualisation of science, education and social research.
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Date Issued: 1994

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Sunbird Movements: a Review, with Posslble Models

- Craig, Adrian J F K, Hulley, Patrick E

Authors: Craig, Adrian J F K , Hulley, Patrick E
Date: 1994
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/447856 , vital:74679 , https://doi.org/10.1080/00306525.1994.9639672
Description: Based on current fieldwork, we propose four possible models to explain the winter influx of sunbirds which we have observed: the birds may be (1) “winter residents”, which move annually to a wintering area and remain there; (2) “shoppers”, which periodically investigate feeding areas within their home range and feed opportunistically where nectar is most abundant; (3) “tourists”, which successively visit a series of sites on a regular itinerary; (4) “nomads”, which move unpredictably to new areas whenever food supplies decline. and have no home base. Current data on sunbird movements are reviewed, and in a few cases the winter resident model is unlikely, but generally it is not yet possible to eliminate any of the hypotheses. Moult cycles based on both field and museum studies may provide additional information, as movements are unlikely while active wing-moult is in progress; some species show interrupted wing-moult, which may be associated with long-distance flights.
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Date Issued: 1994

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A comparison of four microcomputer operating systems

- Wells, George C

Authors: Wells, George C
Date: 1993
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/430422 , vital:72690 , https://doi.org/10.1007/BF01088835
Description: This article describes a comparative study of four operating systems for IBM-PC compatible microcomputers. The assessment concentrated on the suitability of the operating systems for use in real-time applications, and on their use as development environments for real-time systems. The study evaluated the predictability and the performance of the operating systems in several areas critical in real-time systems by using comparative benchmarks. In addition, a small-scale simulation of a process control system was developed for each of the systems. The operating systems that were studied were UNIX, OS/2, QNX and FlexOS. These operating systems represent a broad spectrum of systems from general purpose operating systems to small, specialized real-time operating systems. The details of the evaluation process are given and a summary of the results is presented.
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Date Issued: 1993

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A critique of the proposed council for the environment national core syllabus for environmental education in South Africa

- Taylor, Jim, O'Donoghue, Rob B, Clacherty, Allistair

Authors: Taylor, Jim , O'Donoghue, Rob B , Clacherty, Allistair
Date: 1993
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/450119 , vital:74884
Description: The Department of Environment Affairs, in cooperation with EEASA, undertook a broad consultative process, a central feature of which was the recent Dikhololo Workshop (see Clacherty in this issue). The process led to the Environmental Education Policy Initiative (EEPI), the purpose of which is to foster broad-based processes to promote policy change with respect to environmental education in formal education. The EEPI is not a unilateral initiative; it seeks to work within existing education policy development and change processes.
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Date Issued: 1993

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An annotated bibliography of the Cape honeybee, Apis mellilera capensis Eschscholtz (Hymenoptera: Apidae)

- Hepburn, H Randall, Guye, Sally G

Authors: Hepburn, H Randall , Guye, Sally G
Date: 1993
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/451818 , vital:75079 , https://hdl.handle.net/10520/AJA10213589_64
Description: An annotated bibliography of all known publications on the biology of the Cape honeybee, Apis mellifera capensis Eschscholtz, is presented. The record covers the period 1778 to 1993 and includes 313 entries. One half of these publications have appeared during the last decade.
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Date Issued: 1993

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An association between epichrysomallines and eurytomids (Hymenoptera: Chalcidoidea) in southern African fig wasp communities

- Compton, Stephen G

Authors: Compton, Stephen G
Date: 1993
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/452060 , vital:75100 , https://journals.co.za/doi/pdf/10.10520/AJA10213589_42
Description: Figs, the fruits of Ficus species (Moraceae), support diverse communities/assemblages of fig wasps belonging mainly to the families Agaonidae and Eurytomidae (Boucek et al. 1981; Compton and Hawkins, in press). Southern African fig wasp communities are composed mainly of species associated with the ovules of the plants, either as ovule-gallers or their parasitoids, although some species also gall fig primordia or the walls of the figs (Compton and van Noort 1992). The trophic relationships of only a few fig wasp species have been determined (Compton and van Noort 1992), but these suggest that the various subfamilies of fig wasps are generally consistent in that they contain either gallers or parasitoids. Amongst the gall-forming species are the Epichrysomallinae and Agaoninae (Agaonidae)(Boucek 1988). Eurytomids provide an exception to this general uniformity of larval feeding methods. For example, Sycophila Walker is a major genus of fig wasp eurytomids which includes species that are either gall-formers or parasitoids (Claridge 1959; Boucek 1988).
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Date Issued: 1993

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Ecological correlates of relative brain size in some South African rodents

- Bernard, Ric T F, Nurton, Jane P

Authors: Bernard, Ric T F , Nurton, Jane P
Date: 1993
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/447245 , vital:74599 , https://www.ajol.info/index.php/az/article/view/154234
Description: Relative brain size (size of the brain once body size effects have been removed) has been calculated for 16 species of rodent from South Africa and is shown to vary with six species having a positive RBS (that is a brain larger than expected) and 10 a negative RBS. Arboreal species such as Paraxerus cepapi and Graphiurus murinus and omnivores (G. murinus) have relatively larger brains than do the fossoriai root eaters such as Cryptomys hottentotus and terrestrial follivores (Otomys irroratus). It is suggested that the relatively large brains can be linked to the complex behavioural patterns necessary for locomotion in three dimensions and for utilization of a food resource such as insects that is randomly distributed in time and space. The three sciuromorph rodents (Xerus inauris, Paraxerus cepapi and Pedetes capensis) have very different life styles but all have a positive RBS and it is suggested that a relatively large brain may be a characteristic of the suborder.
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Date Issued: 1993

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Insect herbivores on the exotic weeds Solanum elaeagnifolium Cavanilles and S. sisymbriifolium Lamarck (Solanaceae) in South Africa

- Hill, Martin P, Hulley, Patrick E, Olckers, T

Authors: Hill, Martin P , Hulley, Patrick E , Olckers, T
Date: 1993
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/451454 , vital:75050 , https://hdl.handle.net/10520/AJA10213589_58
Description: In South Africa, the weeds Solanum elaeagnifolium Cavanilles and S. sisymbriifolium Lamarck (Solanaceae) sustain little observable damage from herbivorous insects. Relatively few insect species occur on these plants and at low individual densities. Since native insects are not important in the natural control of S. elaeagnifolium and S. sisymbriifolium, additional agents should be imported for the biological control of these weeds. The absence of important local herbivores means that the possibility of interaction between these and potential biological control agents need not be a consideration in choosing the agents. The nature and numbers of the insect herbivores of S. elaeagnifolium and S. sisymbriifolium are compared with those on another solanaceous weed, S. mauritianum Scopoli, and on native Solanum species. These insect species are discussed relative to plant defence mechanisms.
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Date Issued: 1993

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Interaction of cyanide with iron (II) phthalocyanine

- Nyokong, Tebello

Authors: Nyokong, Tebello
Date: 1993
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/295497 , vital:57347 , xlink:href="https://doi.org/10.1039/DT9930003601"
Description: The kinetics and equilibria for the reaction between cyanide and iron (II) phthalocyanine [Fe(pc)](H2pc = phthalocyanine) in dimethyl sulfoxide (dmso) were studied at 25 °C. The complex [Fe(pc)(CN)2]2– is formed in two consecutive pseudo-first-order processes with k2f= 17.5 ± 0.8 dm3 mol–1 s–1 and k3f= 0.20 ± 0.05 dm3 mol–1 s–1, where k2f and k3f are the rate constants for the binding of the first and second cyanide ligands, respectively. The equilbrium constants were fund to be K2= 3.0 × 103 dm3 mol–1 and K3= 5.7 × 102 dm3 mol–1, for the formation of [Fe(pc)(CN)(dmso)]– and [Fe(pc)(CN)2]2–, respectively.
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Date Issued: 1993

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Kinetics of the reaction of cyanide with ruthenium phthalocyanine complexes

- Nyokong, Tebello, Guthrie-Strachan, Jeffry

Authors: Nyokong, Tebello , Guthrie-Strachan, Jeffry
Date: 1993
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/295509 , vital:57348 , xlink:href="https://doi.org/10.1016/S0020-1693(00)85128-2"
Description: Kinetic studies of the reaction of cyanide with (CO)(DMF)RuPc and (DMSO)2RuPc in DMF are reported. In the presence of a large excess of cyanide, the (CN)2RuPc complex is formed by pseudo first order kinetics. The reaction is first order in both cyanide and phthalocyanine, with specific rate constants of 5.2×10−2 and 7.2×10−2 M−1 s−1 for reactions of cyanide with (CO)(DMF)RuPc and (DMSO)2RuPc, respectively. The rate constants correspond to the coordination of the second cyanide ligand to the ruthenium phthalocyanine species.
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Date Issued: 1993

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Larval development of Gilchristella aestuaria (Gilchrist, 1914)(Pisces: Clupeidae) from southern Africa

- Haigh, Eliria H, Whitfield, Alan K

Authors: Haigh, Eliria H , Whitfield, Alan K
Date: 1993
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/447533 , vital:74654 , https://hdl.handle.net/10520/AJA00445096_482
Description: The larval development of the southern African endemic clupeid Gilchristella aestuaria is descriptionbed and illustrated from specimens collected in the Swartvlei and Sundays estuarine systems of the Cape Province. Free embryos have no visible gut, unpigmented eyes and bodies, and are dependent on the yolk sac contents for nutrnion. This stage lasts until about 4 mm body length (BL) when the eyes become pigmented and a gut becomes visible. Between 4 mm and 7 mm BL melanophores on the ventral aspect of the body form. and the dorsal and caudal fin anlagen develop. Between 7 mm and 8 mm BL the swimbladder forms, flexion occurs and the anal fin anlage develops. By the to mm BL stage most of the skeletal elements have begun to differentiate, with the vertebral centra already showing signs of ossification. General ossification commences between t 2 mm and 13 mm BL. All unpaired fins have the adult complement of rays by 15 mm BL. Scalation starts between 16 mm and 17 mm BL and is complete by 20 mm BL. Body depth increases gradually. from about 5% of BL in the early larval stages to >14% of BL in the juveniles. The pre-anal length decreases from about 87% of BL in the larvae to approximately 69% of BL in the juveniles. Head length increases from approximately 11 % of BL in the larvae to 24-29% of BL in the juveniles. The larval snout is initially 2% of BL, increasing to 7% of BL in the juvenile stages owing to the development of jaw elements.
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Date Issued: 1993

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The nature of the oxidation products of dicyanoruthenium phthalocyanine in aqueous and non-aqueous solvents

- Nyokong, Tebello

Authors: Nyokong, Tebello
Date: 1993
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/295543 , vital:57352 , xlink:href="https://doi.org/10.1016/S0277-5387(00)81741-6"
Description: The cyclic voltammetry of [(CN)2RuIIPc]2− in acetonitrile or dichloromethane shows two oxidation couples at E12 = 0.31 and 0.85 V (vs S.C.E.) in CH2Cl2 and E12 = 0.45 and 1.15 V (vs S.C.E.) in acetonitrile. The spectroelectrochemistry of [(CN)2RuIIPc]2− in these solvents showed that oxidations occur at the phthalocyanine ligand. K2[(CN)2RuIIPc] dissolves in water at pHs greater than 5. The cyclic voltammetry of this complex showed oxidation couples at 0.32 and 0.29 V (vs S.C.E.) for aqueous solutions containing sodium sulphate (0.1M) and for buffered solutions (pH = 9), respectively. Both cyclic voltammetry and controlled potential coulometry gave evidence of electrocrystallization of the oxidation product. Chemical oxidations of [(CN)2RuIIPc]2− in water also showed phthalocyanine ligand oxidation.
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Date Issued: 1993

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The occurrence and development of' Siamese twins' and other abnormalities in Oreochromis mossambicus (Pisces, Cichlidae).

- Holden, Kathleen K, Bruton, Michael N

Authors: Holden, Kathleen K , Bruton, Michael N
Date: 1993
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/447288 , vital:74602 , https://hdl.handle.net/10520/AJA00445096_605
Description: Specimens from a clutch of Oreochromis mossambicus (Pisces, Cichlidae) exhibited a number of abnormalities such as enlarged pericardia, thin tube-like hearts, large depressions in the yolksac, spinal deformities and twinning. Descriptions of the differences in early ontogeny of two pairs of 'Siamese twins' over a period of at least eight days are given. The developmental pattern of the twins is similar to that of normal specimens but the developmental rate is slower in the twins. Possible explanations for these occurrences of polyembryony are given.
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Date Issued: 1993

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The taxonomie status of Apogon enigmaticus Smith, 1961 (Teleostei, Apogonidae)

- Gon, Ofer

Authors: Gon, Ofer
Date: 1993
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/447304 , vital:74603 , https://www.ajol.info/index.php/az/article/view/154224
Description: The validity of the cardinal fish species Apogon enigmaticus, described by Smith (1961) from a single specimen, is reassessed in view of a recent discovery of a second specimen of this species, collected by Smith, in the JLB Smith Institute of Ichthyology. Both fish were re-identified as specimens of A. apogonides (Bleeker, 1856) on the basis of dentition, pigmentation, and counts of pectoral-fin rays, gill rakers and predorsal scales. A. enigmaticas is therefore regarded as a junior synonym of A. apogonides.
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Date Issued: 1993

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