A consequence of nectar feeding?
- Authors: Craig, Adrian J F K , Hulley, Patrick E
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/465245 , vital:76586 , https://sora.unm.edu/node/52068
- Description: Cape White-eyes (Zosterops pallidus) frequently feed on nectar during early winter. This feeding can leave feathers on the forehead matted with nectar and pollen. At least some individuals then shed these feathers, at a time when the annual complete molt has already been terminated. It is suggested that such localized replacement of fouled plumage may occur regularly both in white-eyes and in other short-billed nectar-feeder.
- Full Text:
- Date Issued: 1996
Alkaline rocks in the Kuboos-Bremen Igneous Province, southern Namibia: the Grootpenseiland and Marinkas Kwela Complexes
- Authors: Smithies, Robert H , Marsh, Julian S
- Date: 1996
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145838 , vital:38471
- Description: The early Cambrian Kuboos-Bremen Igneous Province of northwestern South Africa and southern Namibia comprises a series of intrusive bodies that collectively encompass virtually the entire range of alkaline rock types. Two of these bodies, the Grootpenseiland and Marinkas Kwela Complexes lie immediately north of the Orange River and are amongst the few that show this wide lithological range on a local scale.
- Full Text:
- Date Issued: 1996
An extended version of Linda for Transputer systems
- Authors: Wells, George C , Clayton, Peter G , Chalmer, A G
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430512 , vital:72696 , https://dl.acm.org/doi/abs/10.5555/270088.270117
- Description: This paper discusses the associative matching mechanism used in the Linda coordination language for the retrieval of data. There are a number of problems with this mechanism which are discussed in the light of the requirements of applications using Linda. A number of solutions to these problems have been proposed. These are discussed and compared with a new approach to solving these problems. The benefits and the limitations of the new approach are considered, showing how it provides a considerable improvement in this area.
- Full Text:
- Date Issued: 1996
Career needs of Eastern Cape pupils in South Africa
- Authors: Euvrard, George
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/483318 , vital:78743 , https://doi.org/10.1080/03069889608253712
- Description: School guidance and counselling services ought to be designed and implemented to meet the needs of the pupils. The high school guidance programme should operate in a preventive way and attempt to equip pupils with information, skills and attitudes so that they can successfully negotiate the challenges of adolescence. If school group guidance lessons are to meet the pupils' needs and are to be experienced by the pupils as being relevant to their lives, then they must address the expressed needs of the pupils (apart from other issues considered important by appropriate authorities). A methodological approach to defining such needs is presented. It emphasises the importance of the pupils themselves describing their needs, and seeks to avoid the pupils having to respond in the form of ticks and checklists to the ideas of others. The pupil protocols were analysed in a qualitative manner and a number of categories and themes emerged. The needs relating to careers are outlined. Discussion centres on these results, on the differences between schools, and on the implications of these findings for a future single, non-racial education department in South Africa with a common curriculum for all.
- Full Text:
- Date Issued: 1996
Cicadas (Homoptera: Cicadidae) as indicators of habitat and veld condition in valley bushveld in the Great Fish River Valley, South Africa
- Authors: Villet, Martin H , Capitao, I R
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451670 , vital:75068 , https://journals.co.za/doi/pdf/10.10520/AJA10213589_213
- Description: Rural land-use in the Eastern Cape Province ranges from subsistence to commercial farming, with a few game reserves forming areas of active conservation. A large part of the Eastern Cape is covered by Valley Bushveld, a productive veld type dominating the Great Fish River Valley at elevations of 100-450 m (Dyer 1937; Acocks 1988). It is used for game, goat and cattle farming (Stuart-Hill 1991), but large areas have become degraded by overgrazing and invasion by alien or undesirable plants (La Cocket ai. 1990), often with an associated reduction in community richness (Dyer 1937; Acocks 1988). These effects are particularly persistent in this veld type because of the slow regeneration associated with severe climatic conditions (Dyer 1937; Lubke et ai. 1986; La Cock et al. 1990; Stuart-Hill 1991): a mean annual rainfall of only 350-500 mm, mainly between November and March, and temperatures peaking at 46 C in December and January (Acocks 1988). As a result, the more palatable plant species are becoming increasingly rare.
- Full Text:
- Date Issued: 1996
Comparisons of the vocalizations and social behaviour of southern African Pycnonotus bulbuls
- Authors: Lloyd, Penn , Hulley, Patrick E , Craig, Adrian J F K
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447774 , vital:74673 , https://doi.org/10.1080/00306525.1996.9639696
- Description: Vocalizations and associated behaviour of three Pycnonotus species are described, based on field observations and tape recordings from which sonagrams were produced. These species, which are locally sym-patric and hybridize, have similar vocalizations and displays; differences are most apparent in their contact calls and songs. Quantitative analysis of the songs showed that P. barbatus and P. capensis are easily distinguished, whereas the song characteristics of P. nigricans overlap those of both the other species. Playback experiments with territorial male P. barbatus in an area of allopatry showed similar responses to songs of conspecifics and of P. nigricans, but almost no response to the song of P. capensis.
- Full Text:
- Date Issued: 1996
Cyclic voltammetry and spectroelectrochemistry of osmium phthalocyanines in aqueous and non-aqueous solvents
- Authors: Sekota, Mantoa , Nyokong, Tebello
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293358 , vital:57078 , xlink:href="https://doi.org/10.1016/0277-5387(95)00581-1"
- Description: Cyclic voltammetry of osmium phthalocyanine complexes, [(CN)2OsIIPc]2− and (py)2OSIIPc (PC = phthalocyanine dianion), show two oxidation couples and two reduction couples in acetonitrile and dimethy1formamide. Oxidation and reduction in these complexes occur at the ring to form cation and anion radical species, respectively. The [(CN)2OsIIPC]2− complexes show a remarkable ease of ring oxidation with oxidation potentials that are much lower than is typical for metallophthalocyanines. Half-wave potentials of 0.25 and 0.67 V (versus saturated calomel electrode, SCE) were obtained for the first and second ring oxidations, respectively. The [(CN)2OSIIPc]2− complex is soluble in water at pHs greater than 4. This complex shows one oxidation couple in pH 9 buffer at −0.11 V versus SCE.
- Full Text:
- Date Issued: 1996
Discriminant analysis of the honeybee populations of southwestern Africa
- Authors: Radloff, Sarah E , Hepburn, H Randall , Robertson, Mark P , Van Hille, Robert P , Davidson, Z , Villet, Martin H
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451370 , vital:75044 , https://hdl.handle.net/10520/AJA10213589_176
- Description: The morphometric characters and sting pheromones of worker honeybees, Apis mellifera Linnaeus, were analysed by multivariate methods to characterize their populations in southwestern Africa. There is a discrete homogeneous population in northern South Africa and southern Namibia recognized as the subspecies A m. scutellata, a discrete population in northern Namibia recognized as A m. adansonii and a hybrid population between them.
- Full Text: false
- Date Issued: 1996
Does calcium constrain reproductive activity in insectivorous bats? Some empirical evidence for Schreibers’ long-fingered bat (Miniopterus schreibersii)
- Authors: Bernard, Ric T F , Davison, A
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447231 , vital:74598 , https://www.ajol.info/index.php/az/article/view/154435
- Description: Insects are a poor source of dietary calcium and since they are seasonally abundant, it has been suggested that calcium availability may play a significant role in controlling the timing of reproduction in insectivorous bats. To assess the possible role of dietary calcium, we have measured bone calcium concentrations in female and male long-fingered bats (Miniopterus schreibersii) through a full reproductive cycle. The results indicate that winter was not a period of calcium stress and, therefore, that seasonal changes in insect abundance and dietary calcium availability are not a satisfactory explanation for the occurrence of delayed implantation in the long-fingered bat. Bone calcium concentrations of females did not differ significantly throughout pregnancy, indicating that the insects available in winter and early summer were sufficient to meet the calcium demands of pregnancy. Lactating females had the lowest bone calcium concentrations of all specimens, supporting the suggestion that lactation is indeed a period of severe calcium stress in aerial insectivores. We conclude that parturition is probably timed so that lactation coincides with the period of maximal insect abundance and corresponding dietary calcium availability.
- Full Text:
- Date Issued: 1996
Electrocatalytic oxidation of cysteine by molybdenum (V) phthalocyanine complexes
- Authors: Mafatle, Tsukutlane J , Nyokong, Tebello
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293369 , vital:57079 , xlink:href="https://doi.org/10.1016/0022-0728(95)04519-8"
- Description: Chemically modified electrodes, constructed by incorporating oxomolybdenum(V) phthalocyanine (OMo(V)(OH)Pc, Pc = phthalocyanine dianion) into graphite powder were used to catalyse the oxidation of cysteine. Solution catalysis of cysteine by oxomolybdenum(V) tetrasulfophthalocyanine, [OMo(V)(OH)TSPc]4−, was also investigated. A considerable reduction in overpotential for cysteine oxidation was observed. Cysteine oxidation occurred at 0.26 and 0.28 V vs. Ag/vbAgCl for catalysis by Omo(V)(OH)Pc and [OMo(V)(OH)TSPc]4− respectively as opposed to 0.77 V vs. Ag/vbAgCl observed on CoPc chemically modified electrodes. The anodic peak currents vary linearly with cysteine concentration in the range 0.02 to 0.08 mol dm−3 and 0.008 to 0.02 mol dm−3 for [OMo(V)(OH)TSPc]4− and OMo(V)Pc respectively.
- Full Text:
- Date Issued: 1996
Epic into Romance: The Tempest 4.1 and Virgil's Aeneid
- Authors: Wright, Laurence
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/455641 , vital:75445 , https://hdl.handle.net/10520/AJA1011582X_95
- Description: At the conclusion of the betrothal masque for Ferdinand and Miranda, during the dance of the nymphs and reapers, Prospero calls out to the performing spirits," Well done, A void. No more." He has forgotten, as he tells us," that foul conspiracyl Of the beast Caliban and his confed-erates! Against my life"(4.1. 139-41). The entire spectacle vanishes into nothingness. Miranda and Ferdinand are taken aback. Miranda says she's never seen her father in such a state before. Prospero pretends that Ferdinand is alarmed, not by Prospero's own state of emotional disarray, but by the collapse of the masque. And he turns to Ferdinand and launches into what must be one of the three or four best-known speeches in Shakespeare: Be cheerful, sir; Our revels now are ended. These our actors, As I foretold you, were all spirits, and Are melted into air, into thin air, And, like the baseless fabric of this vision, The cloud-capped towers, the gorgeous palaces, The solemn temples, the great globe itself Yea, all which it inherit, shall dissolve, And, like this insub-stantial pageant faded, Leave not a rack behind. We are such stuff As dreams are made on, and our little life Is rounded with a sleep.(4.1. 148-158).
- Full Text:
- Date Issued: 1996
Feeding, tentacle and gut morphology in five species of southern African intertidal holothuroids (Echinodermata)
- Authors: Foster, Gregory G , Hodgson, Alan N
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447392 , vital:74621 , https://hdl.handle.net/10520/AJA00445096_757
- Description: Compares the structure of the tentacles and digestive tracts of four species of intertidal dendrochirote, and one species of aspidochirote holothuroid by using light, scanning and transmission electron microscopy. Gut contents were sieved to determine the size of the particulate matter ingested. Concludes that there appears to be a relationship between tentacle morphology and the size and type of food ingested. Gut length, the thickness of the digestive epithelial layer and the number of vesicles present in the enterocyte cells of the digestive epithelium also differ in relation to the food ingested. Illustrates with several photographs.
- Full Text:
- Date Issued: 1996
Geochemical stratigraphy of the Mohale Dame-Katse Dam areas, Lesotho. Report on contract LHDA, Mohale Tunnel: Sampling and Testing of Cores. Lesotho Highlands Tunnel Partnership (Mohale)
- Authors: Marsh, Julian S
- Date: 1996
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144857 , vital:38385
- Description: In monotonous basalt sequences, such as the Karoo basalt sequence in Lesotho, geochemistry can be a useful adjunct to stratigraphic studies. The acceptance of geochemical criteria in defining stratigraphic units arises from work in the Columbia River Group in NW SA (Swanson et al., 1979) and is now widely employed. It has recently been successfully applied in the Karoo basalts (Marsh et al., in press). In the current investigation a stratigraphic framework for construction work related to the Katse-Mohale tunnel has been developed using the compositions of basalt samples collected from a number of borehole cores in relation to the geochemical stratigraphy of Marshet al. (in press).
- Full Text:
- Date Issued: 1996
Geology Field Trip Guide: Natural Sciences and Geography Educators visit
- Authors: Marsh, Julian S
- Date: 1996
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144878 , vital:38387
- Description: This is a brief guide to some of the interesting geological features in the immediate vicinity of Grahamstown. It summarises the geological history of the area, emphasizes that small-scale geological features are frequently part of much larger features, demonstrates how careful observation of rocks can lead to solving geological problems and reconstruction of ancient environments in which rocks formed, the importance to society, and how rocks in the Grahamstown area have contributed to a global scale understanding of the dynamic nature of planet Earth.
- Full Text:
- Date Issued: 1996
George Webb Hardy's the Black Peril and the social meaning of ‘Black Peril’ in early twentieth-century South Africa
- Authors: Cornwell, Gareth D N
- Date: 1996
- Language: English
- Type: text , article
- Identifier: vital:6116 , http://hdl.handle.net/10962/d1004240 , https://doi.org/10.1080/03057079608708504
- Description: preprint , The 'Black Peril' — the threatened rape of white women by black men — was an important factor in the moral economy underpinning colonial debate about the 'Native Question' in early twentieth-century South Africa. This essay gives sympathetic consideration to studies which have attempted to link the recurrence of Black Peril panics with specific disturbances in the economy or body politic, before offering symptomatic readings of two pieces of writing by George Webb Hardy, the article 'The Black Peril' (1904) and the novel The Black Peril (1912). These readings suggest that the rape threat was essentially a rationalization of white men's fear of sexual competition from black men. The imagery of purity and contagion, in terms of which the 'endogamous imperative' is typically represented in such texts, suggests that the idea of caste may usefully be invoked in attempts to explain the seemingly irrational public hysteria surrounding the Black Peril phenomenon.
- Full Text:
- Date Issued: 1996
Karoo and Etendeks flood basalt provinces, southern Africa and the tectonic development of their adjacent margins:
- Authors: Marsh, Julian S , Watkeys, M K
- Date: 1996
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144868 , vital:38386
- Description: Southern Africa hosts remnants of two continental flood basalt provinces emplaced in association with fragmentation of Gondwana. The earliest is the 183 Ma Karoo Province whose relationship to continental breakup and sea floor spreading is complex. Geochemical stratigraphy, Ar-Ar Dating and palaeomagnetism indicate that Karoo mafic igneous rocks throughout Southern Africa were emplaced over a very short interval at 183 Ma.
- Full Text:
- Date Issued: 1996
Lectotype designation and a new synonym of Cloeodes inzingae (Crass, 1947)(Ephemeroptera: Baetidae)
- Authors: de Moor, Ferdy C , McCafferty, W P
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/452143 , vital:75107 , https://journals.co.za/doi/pdf/10.10520/AJA10213589_209
- Description: The description of Pseudocloeon inzingae Crass, 1947, was based on nymphs and reared adults collected from several rivers in KwaZulu-Natal in 1944 and 1945. The species was redescribed by Waltz and McCafferty (1994) and transferred to Cloeodes Traver, a genus previously known only from the Neotropical Region and southeast Asia. Pseudocloeon saxophilum Agnew, 1961, from the Western Cape Province of South Africa was also transferred to Cloeodes by Waltz and McCafferty (1994), and both species were listed under this genus in the recent checklist of South African Ephemeroptera by McCafferty and de Moor (1995). We have studied nymphs and adults of C. inzingae in the Albany Museum, Grahamstown, which clearly represent at least part of the original rnaterial studied by Crass, and may thus be considered syntypes.
- Full Text:
- Date Issued: 1996
Marine algal remains from the Upper Devonian of South Africa
- Authors: Hiller, Norton , Gess, Robert W
- Date: 1996
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/72753 , vital:30107 , https://doi.org/10.1016/0034-6667(95)00062-3
- Description: The remains of what are interpreted to be marine brown algae are described from Late Devonian clastic rocks in South Africa. Dichotomously-branched specimens with rounded terminations are placed in the new species Hungerfordia fionae and the closely related H. dichotoma Fry and Banks is placed in synonymy with Buthotrephis trichotoma Douglas and Jell. A large strap-like form is described as a new species, Yeaia africana.
- Full Text: false
- Date Issued: 1996
Perceptions of affirmative action
- Authors: Scott, Judith , Amos, Trevor L , Richard Scott, W
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/270914 , vital:54491 , xlink:href="https://hdl.handle.net/10520/EJC-67e7bffd2"
- Description: Private and public South African employers have instituted affirmative action policies meant to provide employment opportunities to Black South Africans. A body of literature suggests that because of affirmative action policies Black hopes have been raised while Whites view such policies as having a negative impact on their opportunities. However, no extant literature details an empirical investigation of these suggestions. Therefore, this study focusses on the affirmative action perceptions held by 350 South African university commerce students.
- Full Text:
- Date Issued: 1996
Pharmacokinetics of cyclizine following intravenous administration to human volunteers
- Authors: Kanfer, Isadore , Walker, Roderick B
- Date: 1996
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184389 , vital:44214 , xlink:href="https://doi.org/10.1016/0928-0987(96)00177-7"
- Description: The pharmacokinetics of cyclizine, a piperazine derivative useful in the prevention and treatment of nausea and vomiting, was investigated in six healthy male volunteers following an intravenous bolus dose. The drug is extensively distributed with a mean volume of distribution of 16.50 ± 3.33 l/kg and a mean total clearance of 0.870 ± 0.105 l/h per kg. Urinary excretion data showed that less than one percent of the dose was excreted up to 36 h as unchanged drug in the urine. The extremely low mean renal clearance (0.005 ± 0.002 l/h per kg) for the parent drug comprised only a small proportion of total clearance indicating that urinary excretion of parent drug is not a major route of elimination for cyclizine. The drug appears to exhibit biexponential pharmacokinetics and has a terminal elimination half-life of approximately 13 h.
- Full Text:
- Date Issued: 1996