The relationship between subjective well-being and domain satisfactions in South Africa
- Authors: Moller, Valerie , Saris, W E
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:7116 , http://hdl.handle.net/10962/d1010749 , http://dx.doi.org/10.1023/A:1010851412273
- Description: This paper examines the relationship between subjective well-being and domain satisfactions. In the past different models have been specified. The most commonly applied model is the bottom-up model in which domain satisfactions affect subjective well-being. The more recent top-down model suggests a reversed relationship. Finally there is the supposition that the correlations between these variables can be spurious due to the effect of personality characteristics. Empirical research has shown that different models are found for different domains and in different countries. Focussing on the effects of the domain satisfactions of finances, housing and social contacts it has been found that subjective well-being is mainly affected by satisfaction with social contacts in Western developed countries and by satisfaction with finances in East European countries. The question we should like to answer in this study is whether a similar pattern obtains for the factors which influence subjective well-being among the different race groups in South Africa. Interestingly, coloured people and Asians did indeed show the expected effects but the groups with the most extreme living conditions did not. Evaluation of life circumstances by black and white South Africans was determined by expectations for the future rather than by current living conditions. This surprising result is discussed in the light of the political situation in South Africa.
- Full Text:
- Date Issued: 2001
Working conditions agreement for SACCAWU employees
- Authors: SACCAWU
- Date: 2001
- Subjects: SACCAWU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/175924 , vital:42641
- Description: As a SACCAWU Staff Member it is important to know exactly what your Conditions of Service are hence this booklet. The Union believes in the principle of good and fair treatment of Staff and sees this as encouraging motivated and dedicated Officials. We have therefore tried to make Conditions as favourable as possible within the constraints of being a no-profit making organisation. In return, however the organisation does expect diligence, commitment and efficiency. Staff have the right before 1st March, every year to put forward proposals to* National Finance Committee in order to improve Working Conditions. Two Representatives elected from each Region will attend National Discussions/Engagements which shall put together a national mandate and elect Representatives to meet with NFC.
- Full Text:
- Date Issued: 2001
Intertidal population structure of the edible mollusc Turbo sarmaticus (Vetigastropoda) at an unexploited and exploited sites along the coast of the Eastern Cape Province, South Africa
- Authors: Foster, Gregory G , Hodgson, Alan N
- Date: 2000
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447403 , vital:74622 , https://doi.org/10.1080/15627020.2000.11657088
- Description: The intertidal population structure of the large edible gastropod Turbo sarmaticus was examined at four sites along the Eastern Cape Province of South Africa. One site was free from exploitation, two were subjected to low levels of exploitationand one was heavily exploited. Within the intertidal zone at all sites there was a size-related distribution, with smalleranimals being found towards the upper mid-shore and larger animals occurring in a downshore direction. The mean shore densities (1.2–animals/m2) and biomass (4.4–9.4 g/m2) of T. sarmaticus at the sites where there was no, or minimal, exploitation of animals were not significantly different (P0.001). However, the largest animals (up to 110mmshell length) were found at the unexploited site, an offshore island. The lowest density (0.2 animals/m2) and biomass (0.4 g/m2) of T. sarmaticus was recorded at the site where the exploitation of this gastropod was intense. In addition, no animals of a legally exploitable size (>70 mm shell length) were found. It is suggested that intense over-exploitation is threatening the population at this site.
- Full Text:
- Date Issued: 2000
Phloem loading in the sucrose-export-defective (SXD-1) mutant maize is limited by callose deposition at plasmodesmata in bundle sheath-vascular parenchyma interface
- Authors: Botha, Christiaan E J , Cross, Robin H M , Van Bel, A J E , Peter, Craig I
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6503 , http://hdl.handle.net/10962/d1005926
- Description: Using Lucifer Yellow we have demonstrated that the phloem-loading pathway from the mesophyll to the bundle sheath-vascular parenchyma interface in Zea mays source leaves follows a symplasmic route in small and intermediate vascular bundles in control as well as in the green sections of mutant sucrose-export-defective (SXD-1) plants. In the anthocyanin-rich mutant leaf sections, Lucifer Yellow transport was prohibited along the same path, at the bundle sheath-vascular parenchyma interface in particular. Plasmodesmata at the latter interface in SXD-1 anthocyanin-rich leaf sections appear to be structurally altered through callose deposition at the plasmodesmal orifices. We suggest that a transport bottleneck at the bundle sheath-vascular parenchyma interface is thus orchestrated and regulated through callose formation, preventing symplasmic transport across this important loading interface.
- Full Text:
- Date Issued: 2000
Towards reconciliation of structure with function in plasmodesmata—who is the gatekeeper?
- Authors: Botha, Christiaan E J , Cross, Robin H M
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6497 , http://hdl.handle.net/10962/d1004493
- Description: Whilst the structure of higher plant plasmodesmata was first described by Robards (1963. Desmotubule—a plasmodesmatal substructure. Nature 218, 784), and despite many subsequent intensive investigations, there is still much that remains unclear relating to their ultrastructure and functioning in higher plants. We have examined chemically fixed plant material, and suggest that the conformational changes seen in plasmodesmatal substructure, particularly the deposition of electron-dense extra-plasmodesmal material, is linked to either manipulation of the hormonal balance (as in Avocado fruit), or of osmotic potential in leaf blade material. These changes result in the deposition of β 1,3-glucan (callose) at the neck region of these plasmodesmata. This electron-dense material is deposited at the neck region of plasmodesmata, and forms a collar-like structure. The formation of a collar is shown to be coupled with loss of lucence within the cytoplasmic sleeve. The formation of a collar at the plasmodesmatal orifice thus results in encapsulation and closure of the plasmodesmatal orifice. Closure of the orifice coincides with a loss of electron-lucence and a lack of resolution of the desmotubule. These ultrastructural changes are potentially significant and could contribute to, result in, or assist in the down-regulation of cell to cell trafficking via plasmodesmata.
- Full Text:
- Date Issued: 2000
Analysis of chromameter results obtained from corticosteroid-induced skin blanching assay: comparison of visual and chromameter data
- Authors: Schwarb, Fabian P , Smith, Eric W , Haigh, John M , Surber, Christian
- Date: 1999
- Language: English
- Type: text , Article
- Identifier: vital:6426 , http://hdl.handle.net/10962/d1006562
- Description: In a Guidance document, the American FDA recommends the use of a Minolta chromameter rather than the human eye for the quantitative assessment of the pharmacodynamic blanching response produced by topical application of corticosteroids. The purpose of this study was to compare the appropriateness of the human eye and two models of chromameter for the estimation of skin blanching, in terms of the quality of the data generated by each method. The corticosteroid-induced skin blanching from four different betamethasone 17-valerate cream formulations was compared in a typical human skin blanching trial. The optimized assay methodology routinely practised in our laboratories was utilized. The blanching responses were assessed visually by three trained, independent observers and recorded by two chromameters (Minolta model CR-200 and model CR-300). The topical availability of the four creams was determined using visual scoring and chromameter measurements. All data were manipulated in such a manner as to produce a blanching response versus time profile from which AUBC analysis could be performed. Good correlation was observed between the visual assessments made by three independent observers. In contrast, moderate correlation was determined between visual, CR-200 and CR-300 measurements. Surprisingly, no direct linear relationship between the AUBCs produced by the two chromameters was observed indicating that the quality of the data obtained from the two instruments may not be equal. This investigation also indicated that the use of the chromameter is not completely objective. Visual scoring and chromameter measurement produce data sets that differ in quality. Each procedure needs to be validated and investigators have to be trained for both visual assessment and the operation of the chromameter, particularly with regard to the manipulation of the measuring head of the instrument.
- Full Text:
- Date Issued: 1999
Cicadas (Hemiptera, Homoptera: Cicadoidea) of Mkomazi
- Authors: Villet, Martin H , van Noort, Simon , Packer, M
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/442756 , vital:74030 , ISBN , https://doi.org/10.1046/j.1472-4642.2001.00094.x
- Description: The cicadas are a group of insects belonging to the order Hemiptera which comprises a diverse range of insects including the bugs, leafhoppers, aphids, scale insects etc. The Hemiptera are characterised by specialised mouth parts that are adapted for piercing and sucking up sap from host plants or animal juices from their prey. All cicadas are plant feeders and can be extremely camouflaged when sitting and feeding on a branch, although the males give themselves away by their persistent, often high pitched calls.
- Full Text:
- Date Issued: 1999
Description of adult and larva of Ichnestoma pringlei n. sp. (Coleoptera: Scarabaeidae Cetoniinae), with notes on its biology and ecology
- Authors: Perissinotto, Renzo , Smith, Tamara J , Stobbia, P
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/453815 , vital:75289 , https://doi.org/10.1080/03946975.1999.10539390
- Description: There are at present 10 described species in the primitive genus Ichnestoma Gory and Percheron 1833. These are all phylogenetic and geographic relicts of high evolutionary and conservation interest. The discovery of a new species, I. pringlei n. sp., and the first description of a larva (third instar) of this genus are reported here. New information is also presented on their life-cycle and on the dependence of their activities on rainfall patterns, particularly in the semi-arid region of the Karoo. In this region, larvae seem to take 2 years to complete growth and metamorphosis since they feed only after major rainfall events, while remaining inactive and deep underground during dry periods. Adults emerge from their cocoons only after summer rains of at least 15 mm. They lack functional mouth parts and are unable to feed. Their life span is only 3–5 days. Because females are completely flightless and unable to disperse, species of the genus are extremely vulnerable to environmental degradation. It seems likely that they may play a key role in the decomposition of dead plant matter, especially in dry and clay-rich soils where other primary decomposers are scarce.
- Full Text:
- Date Issued: 1999
On the life history of a cyprinid fish, Labeo cylindricus
- Authors: Weyl, Olaf L F , Booth, Anthony J
- Date: 1999
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125408 , vital:35780 , https://doi.10.1023/A:1007543319416
- Description: Fishes of the genus Labeo are widely distributed throughout Africa and consist of at least 80 species which comprise 16.4% of the African cyprinid ichthyofauna (Reid 1985). Most labeo species are also commercially important throughout the African continent, having contributed significantly to various fisheries. Their roe (sensu caviar) is often harvested as an additional bycatch (Skelton et al. 1991). Despite their obvious importance, the few studies that have investigated aspects of their life history have been conducted on the larger commercial species (Lowe 1952, Mulder 1973, Balon et al. 1974, Potgieter 1974, Baird 1976, Tomasson et al. 1984, van Zyl et al. 1995).
- Full Text:
- Date Issued: 1999
Problems in rural transformation in South Africa specifically in the land reform arena:
- Authors: Antrobus, Geoffrey G , Fraser, Gavin C G , Tapson, D R
- Date: 1998
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143035 , vital:38195 , https://www.infona.pl/resource/bwmeta1.element.agro-article-dc77672d-7269-4641-bf99-605eaa5fe369
- Description: Problems in rural transformation in South Africa specifically in the land reform arena
- Full Text:
- Date Issued: 1998
Spatial and temporal variability in recruitment of intertidal mussels around the coast of southern Africa
- Authors: Harris, Jean M , Branch, George M , Elliot, Bridget L , Currie, Bronwen , Dye, Arthur H , McQuaid, Christopher D , Tomalin, Bruce J , Velasquez, Claudio
- Date: 1998
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447579 , vital:74658 , https://www.ajol.info/index.php/az/article/view/154717
- Description: Intensity of intertidal mussel recruitment was compared across a range of different spatial and temporal scales around the coast of southern Africa between June 1995 and October 1996. Comparison of the east and west coasts revealed significantly higher recruit densities on the west coast, corresponding to larger adult densities. This difference between the two coasts reflects biogeographic disparities in mussel species composition, growth rates and spawning intensities, oceanographic conditions and productivity. Significant spatial variations in recruitment were recorded between regions 100–1000 km apart and between localities 1–25 km apart. Results suggest that the influence of dispersal processes on recruitment patterns acts at a relatively small scale, and may affect the distribution and abundance of adults among shores only a few kilometres apart.
- Full Text:
- Date Issued: 1998
The biology of Tilapia rendalli and Oreochromis mossambicus (Pisces: Cichlidae) in a subtropical lake in Mozambique
- Authors: Weyl, Olaf L F , Hecht, Thomas
- Date: 1998
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446944 , vital:74572 , https://www.ajol.info/index.php/az/article/view/154744
- Description: This study of age and growth, reproduction and juvenile recruitment of Tilapia rendalli and Oreochromis mossambicus was undertaken in Lake Chicamba, a large, clear subtropical lake in central Mozambique. Sectioned otoliths were used to estimate age. Marginal zone analysis showed that annulus formation occurred during winter, in July and August. Maximum age estimates for T. rendalli and O. mossambicus were 16 and 10 years, respectively. Growth was described by the 3 parameter von Bertalanffy model as Lt= 238.74 (1-e-0,636 (1+ 00905)) mm TL for T. rendalli and Lt= 266.06 (1-e-0 70904 (1+ 0269)) mm TL for O. mossambicus. The length-at-50% maturity (Lm 50) of male T. rendalli was 218 mm total lenglh (TL) and 205 mm TL in females. In O. mossambicus the Lm 50 for males was 251 mm TL and for females 223 mm TL. Both species spawned throughout summer. Lake level was found to have no effect on spawning periodicity although recruitment was flood dependent.
- Full Text:
- Date Issued: 1998
Learning from the people : participatory rural appraisal, geography and rural development in the 'new' South Africa
- Authors: Binns, Tony , Hill, Trevor R , Nel, Etienne L
- Date: 1997
- Language: English
- Type: Article
- Identifier: vital:6675 , http://hdl.handle.net/10962/d1006649
- Description: Top-down rural development strategies in Africa have generally not succeeded in raising living standards among the rural poor. It is argued that inappropriate development strategies have stemmed from methodologies that fail to appreciate the whole picture in rural communities, and in particular ignore local people's perceptions, needs and understanding. Participatory Rural Appraisal (PRA) represents a significant step forward in the design of methodologies and a selection of these techniques is evaluated. Many PRA methods have much in common with the field research methods that have been used by geographers over many years to interpret people-environment relationships. A research investigation in Eastern Cape Province, South Africa, suggests that geographers could have an important role to play in this area of applied research and, in particular, in the context of post-apartheid South Africa there is an urgent challenge to be met in promoting rural development in poor, former black Homeland areas.
- Full Text:
- Date Issued: 1997
Novas, eclipses and the English stage, 1598-1608
- Authors: Butler, Guy F
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/457738 , vital:75675 , https://hdl.handle.net/10520/AJA1011582X_6
- Description: In the sixteenth and early-seventeenth centuries very few kings, queens or councillors or, indeed, ordinary folk, made any important decisions without consulting their horoscopes. There is no reason to believe that Shakespeare was more sceptical about astrological prediction than his tough-minded Queen; but, even if he were sceptical, he could and did exploit his audience's susceptibility for dramatic ends. A reference to the stars could lift his action from the earthly to the cosmic. Astrological phenomena signalled the involvement of the Heavens with human affairs. In a sense, he and his fellow-dramatists had no option but to exploit the Heavens, because the canopy over half of the Elizabethan stage was referred to as 'the heavens.' It was adorned with paintings of the planets and the signs of the Zodiac. The heavens were built into his theatre, Let us start with eclipses of the sun and moon.
- Full Text:
- Date Issued: 1997
Patterns of sexual size dimorphism in African cichlid fishes
- Authors: Erlandsson, A , Ribbink, Anthony J
- Date: 1997
- Language: English
- Type: Article
- Identifier: vital:7135 , http://hdl.handle.net/10962/d1011778
- Description: Although the Cichlidae is a well-studied family of African fishes, the evolution of sexual size dimorphism (SSD) and its relation to life-history, behaviour, feeding and habitat have not been comparatively examined. The investigation of SSD reported here was based on a study of the scientific literature. Prerequisites to such studies are records of maximum size of adult males and females. Disappointingly few authors published such measurements, so the data are fewer than anticipated given that the cichlids are such a species-rich group. Now that this omission has been noted, it is hoped that investigations of the future will include information on maximum size of adults of both sexes. Data from 215 species showed great variation in the degree and direction of SSD, without any really strong trends being evident. In the majority of species, males were larger than females or there was no size difference between the sexes. In 10% (21 species), females were larger than males. All of these are lacustrine, tend to live in deep water, often over muddy substrata and to feed to a greater extent than expected on non-defendable food sources. The degree of SSD increases with increasing body size in species where males are the larger sex and decreases in species where females are the larger In territorial species, in which competition between territorial males is intensive, males are the larger sex. The expectation that polygynous cichlids would show a more marked degree of SSD than monogamous species was not met. Larger size in females (with one exception) occurs in mouthbrooding species only. Males are the larger sex in substratum brooders. It seems that the degree and direction of sexual size dimorphism in cichlids is a consequence of a balance of natural and sexual selection, but there is a need to increase the sample size to understand the interplay of these selection pressures and to establish the validity of the emerging trends.
- Full Text: false
- Date Issued: 1997
Plasmodesmatal frequency in relation to short-distance transport and phloem loading in leaves of barley (Hordeum vulgare). Phloem is not loaded directly from the symplast
- Authors: Botha, Christiaan E J , Cross, Robin H M
- Date: 1997
- Language: English
- Type: Article
- Identifier: vital:6504 , http://hdl.handle.net/10962/d1005928
- Description: We investigated the phloem loading pathway in barley, by determining plasmodesmatal frequencies at the electron microscope level for both intermediate and small blade bundles of mature barley leaves. Lucifer yellow was injected intercellularly into bundle sheath, vascular parenchyma, and thin-walled sieve tubes. Passage of this symplastically transported dye was monitored with an epifluorescence microscope under blue light. Low plasmodesmatal frequencies endarch to the bundle sheath cells are relatively low for most interfaces terminating at the thin- and thick-walled sieve tubes within this C3 species. Lack of connections between vascular parenchyma and sieve tubes, and low frequencies (0.5% plasmodesmata per μm cell wall interface) of connections between vascular parenchyma and companion cells, as well as the very low frequency of pore-plasmodesmatal connections between companion cells and sieve tubes in small bundles (0.2% plasmodesmata per μm cell wall interface), suggest that the companion cell-sieve tube complex is symplastically isolated from other vascular parenchyma cells in small bundles. The degree of cellular connectivity and the potential isolation of the companion cell-sieve tube complex was determined electrophysiologically, using an electrometer coupled to microcapillary electrodes. The less negative cell potential {average -52 mV) from mesophyll to the vascular parenchyma cells contrasted sharply with the more negative potential (-122.5 mV) recorded for the companion cell-thin-walled sieve tube complex. Although intercellular injection of lucifer yellow clearly demonstrated rapid (0.75 μm s-1) longitudinal and radial transport in the bundle sheath-vascular parenchyma complex, as well as from the bundle sheath through transverse veins to adjacent longitudinal veins, we were neither able to detect nor present unequivocal evidence in support of the symplastic connectivity of the sieve tubes to the vascular parenchyma. Injection of the companion cell-sieve tube complex, did not demonstrate backward connectivity to the bundle sheath. We conclude that the low plasmodesmatal frequencies, coupled with a two-domain electropotential zonation configuration, and the negative transport experiments using lucifer yellow, precludes symplastic phloem loading in barley leaves.
- Full Text:
- Date Issued: 1997
A review of estuarine ichthyology in South Africa over the past 50 years
- Authors: Whitfield, Alan K
- Date: 1996
- Language: English
- Type: text , Article
- Identifier: vital:7155 , http://hdl.handle.net/10962/d1011873
- Description: Progress in South African estuarine ichthyology between 1946 and 1995 is reviewed. The early estuary surveys of the 1950s and 1960s resulted in the compilation of species lists for individual systems, but contained very little biological or ecological information on fishes. These surveys were superseded by both autecological and synecological studies in the 1970s and 1980s, which yielded descriptive and process-orientated information on a wide variety of species. Estuarine research during the 1990s has focused increasingly at the community level, with several review papers on the life-history styles of groups of estuarine-associated fishes being published. The last decade has also seen the departure of a number of senior estuarine ichthyologists from the field. This decline in available expertise has coincided with increased demand for ichthyological information to be used in decision support systems for the wise management and conservation of estuaries. It is suggested that these demands be seen as a challenge, with studies being directed towards providing the type of information needed for the maintenance of vital ecological processes within these systems.
- Full Text: false
- Date Issued: 1996
Bleak future for multi-party elections in Kenya
- Authors: Fox, Roddy C
- Date: 1996
- Language: English
- Type: Article
- Identifier: vital:6683 , http://hdl.handle.net/10962/d1006681
- Description: With attention turning towards Kenya's second multi-party elections, due to be held before the end of 1997, it is imperative to look back to the flaws in the system which helped deliver President Daniel arap Moi and the Kenya African National Union (KANU) their victories in 1992. At present there is no sign of these defects being eradicated and the creation of new districts since then has demonstrated the Government's intention of enhancing an already biased structure. The underlying distribution of tribes and ethnic groups has had a fundamental impact on the electoral geography of Kenya, since they have controlled the delimitation of both the parliamentary constituencies and the administrative machinery of the whole country.
- Full Text:
- Date Issued: 1996
Fifty years of ichthyology in Grahamstown
- Authors: Skelton, Paul H
- Date: 1996
- Language: English
- Type: text , Article
- Identifier: vital:7138 , http://hdl.handle.net/10962/d1011816
- Description: In July 1946, the fledgling Council for Scientific and Industrial Research (CSIR) awarded Dr J.L.B. (James Leonard Brierley) Smith of Rhodes University College a research fellowship of £800 to enable him to devote his energies to ichthyology. The university responded by providing accommodation, equipment and appointing Smith a research professor. These actions marked the beginning of what has become a major academic development in Grahamstown as represented by the J.L.B. Smith Institute of Ichthyology, the Department of Ichthyology and Fisheries Science (DIFS), and the Freshwater Fish Section at the Albany Museum. At present more than 40 people are employed in one way or other in these organizations, more than 20 of them professionals, in addition to whom there are 41 postgraduate students currently studying ichthyology or fisheries science through DIFS at Rhodes University. Altogether this represents a concentration of ichthyological expertise probably unmatched anywhere else in the world. It is opportune therefore to highlight a few of the more significant milestones in the history of ichthyology in Grahamstown and so illuminate some of the key factors behind this achievement.
- Full Text:
- Date Issued: 1996
Late Devonian charophytes from the Witteberg Group, South Africa
- Authors: Gess, Robert W , Hiller, Norton
- Date: 1995
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/72742 , vital:30106 , https://doi.org/10.1016/0034-6667(95)00007-8
- Description: The first record of Palaeozoic charophytes from southern Africa allows the establishment of two new genera to which are assigned four new species, Octochara crassa, O. gracilis. Hexachara setacea, and H. riniensis. Each species is represented by both vegetative and reproductive structures and suggested reconstructions are presented. Associated plant and animal remains, and the sedimentology and geochemistry of the containing rocks indicate that the charophytes probably grew in the shallow parts of a brackish coastal lagoon.
- Full Text: false
- Date Issued: 1995