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Fish community structure in three temporarily open/closed estuaries on the Natal coast

  • Authors: Harrison, Trevor D , Whitfield, Alan K
  • Date: 1995
  • Language: English
  • Type: Text
  • Identifier: vital:15026 , http://hdl.handle.net/10962/d1019890 , ISSN 0073-4381 , Ichthyological Bulletin J.L.B. Smith Institute of Ichthyology; No. 64
  • Description: The fishes of three small Natal estuaries, the Mhlanga, Damba and Zotsha were sampled over a period of two years. A total of 68 fish taxa representing 24 families, 39 genera and 55 species were captured during this study. Forty seven fish taxa were recorded in the Mhlanga estuary of which Gilchristella aestuaria, Oreochromis mossambicus, Valamugil cunnesius, Valamugil sp. and juvenile mugilids numerically dominated. In terms of biomass, O. mossambicus, V. cunnesius, Liza alata, Myxus capensis and Mugil cephalus dominated the ichthyofauna of the Mhlanga system. In the Damba estuary, 24 fish taxa were recorded, the most abundant being Glossogobius callidus,M. capensis and 0. mossambicus. M. capensis, M. cephalus, O. mossambicus and G. callidus dominated the fish biomass captured in the Damba system. A total of 56 fish taxa were recorded in the Zotsha estuary during this study, with the ichthyofauna numerically dominated by juvenile mugilids, G. aestuaria, O. mossambicus, Rhabdosargus holubi, Terapon jarbua, Ambassis productus and G. callidus. The species which dominated the fish biomass in the Zotsha system were 0. mossambicus L. alata, Valamugil robustus, V. buchanani, M. capensis, M. cephalus and V. cunnesius. Classifying the species according to whether they were resident estuarine, freshwater, estuarine-dependent marine or marine species revealed that the first three groups were all well represented in the systems. Oreochromis mossambicus was the dominant freshwater species in all three estuaries. Gilchristella aestuaria and Glossogobius callidus were the principal estuarine species in the Mhlanga and the Damba respectively, with G. aestuaria, A. productus and G. callidus being the dominant estuarine species captured in the Zotsha. The principal estuarine-dependent marine fishes captured in the Mhlanga were V. cunnesius, Valamugil sp., juvenile mugilids, M. capensis, M. cephalus and L. alata. In the Damba, M. capensis and M. cephalus were the dominant estuarine-dependent marine species and in the Zotsha juvenile mugilids, R. holubi, T. jarbua, M. capensis, V. cunnesius, V. robustus, M. cephalus, L. alata and V. buchanani were the principal estuarine-dependent marine species. The results of this study indicate that the estuaries are dominated at different periods by different assemblages of fishes. This is linked to the spawning and migration patterns of the various species as well as the hydrological regime of each estuary. During the winter these systems are normally closed with relatively deep waters and high food resource and habitat availability. Freshwater and estuarine species mainly inhabit the upper reaches of the systems while estuarine-dependent marine species, which dominate the fish community, mainly occupy the middle and lower reaches. When these estuaries open with the onset of the spring/summer rains, adult and sub-adult estuarine-dependent marine species emigrate to the marine environment and juveniles begin recruiting into the systems. Spring is also the peak breeding period of resident estuarine and freshwater species, resulting in an increase in the contribution of these fishes to the overall ichthyofauna during this period. When closed estuaries open the water level falls and this results in the fishes concentrating in the lower reaches of the system where moderate water depths are present, thus further contributing to an increase in the proportion of freshwater and estuarine species in this region. The breaching of closed estuaries also results in a reduction in food resources and habitat availability. Competition and possible increased vulnerability to avian predation (due to the shallow nature of the systems), may contribute to a decrease in the proportion of estuarine and freshwater species in summer. The prolonged recruitment of Of-juveniles of estuarine-dependent marine species results in an increase in the proportion of these fishes present in the estuaries during summer. In autumn, the systems normally close, water levels rise and available food resources and habitat increase. This allows the redistribution of freshwater and estuarine species upstream, leaving estuarine-dependent marine species to dominate the middle and lower reaches. Although temporarily open/closed estuaries along the Natal coast may not be as diverse as permanently open estuaries in terms of their ichthyofauna, their importance must not be underestimated, since by providing a series of sheltered habitats along the coast they may contribute significantly to the viability of estuarine-dependent marine fish stocks. , Rhodes University Libraries (Digitisation)
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  • Date Issued: 1995

Fishes of the Tristan da Cunha Group and Gough Island, South Atlantic Ocean

  • Authors: Andrew, T G , Hecht, Thomas , Heemstra, Phillip C , Lutjeharms, J R E
  • Date: 1995
  • Language: English
  • Type: Text
  • Identifier: vital:15025 , http://hdl.handle.net/10962/d1019889 , ISSN 0073-4381 , Ichthyological Bulletin J.L.B. Smith Institute of Ichthyology; No. 63
  • Description: Recent collections of fishes from the South Atlantic islands of the Tristan da Cunha Group (Tristan, Inaccessible and Nightingale) and Gough Island have produced 25 new records. Fifty one species are known to occur in the near-shore waters of the islands (46 of these are documented by specimens and another 5 species are probable). A diagnosis, synonymy and in most cases, an illustration, are provided for each species. For certain species, brief notes on biology, relative abundance and seasonal distribution are included. The neritic ichthyofauna of the Subtropical Convergence (STC) region is characterized, and the importance of this frontal zone as a barrier to dispersal of species in the Southern Ocean is evaluated. Analysis of the zoogeographic affinities of the Tristan/Gough fish fauna resulted in a redefinition of the West Wind Drift Islands Province (WWDI), comprising the Tristan Group and Gough in the South Atlantic and St. Paul and Amsterdam Islands in the southern Indian Ocean. Verna Seamount (west of Cape Town) and Walters Shoal (south of Madagascar) are excluded from the WWDI Province, as the affinities of their poorly-known fish faunas appear to be more with South Africa and the tropical Indian Ocean respectively. , Rhodes University Libraries (Digitisation)
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  • Date Issued: 1995

Foreign labour migration to South Africa after apartheid: continuity or change?

  • Authors: Myataza, Lutando Samuel
  • Date: 1995
  • Subjects: Foreign workers -- South Africa , Black people -- Employment -- South Africa
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:2813 , http://hdl.handle.net/10962/d1003023 , Foreign workers -- South Africa , Black people -- Employment -- South Africa
  • Description: Migrant labour constitutes one of the perennial problems of the political economy of the Southern African region. The movement of people between their home countries and the gold mines in South Africa is over a hundred years old. In this sense, labour migrancy predates apartheid, and is now threatening to outlive it. Migrants working in South Africa make up a sizable proportion of the total wage earning population of the neighbouring countries (Botswana, Lesotho, Swaziland, Mozambique and Malawi). Their entrenched dependence on migrant-based revenue has made them vulnerable to fluctuations in labour flows to the gold mines (Davies, 1992) The developments since the first quarter of 1988 have altered the terms of debate on migrant labour. With the independence of Namibia and the establishment of a new government in South Africa, to name but a few, the pattern of future regional cooperation has become a central issue. Likewise, the debate about labour migrancy has entered a new phase. Given the current political changes, and yet to take place, this study constitutes a modest attempt to contribute to the debate by examining the prospects of restructuring of labour migrancy to the gold mining industry. The central aim of this undertaking will be to establish what the future holds for the foreign component of the labour force. The focus here will be on the emerging debates in this area, policy pronouncements by major stakeholders, the Chamber of Mines and the new Government of National Unity. However, an informed forecast on the future of labour migrancy is possible only if we establish the conditions that created it in the first place; how it has been constructed overtime; and the successive moments of transformation in the system. In this regard, this study will locate the origins and development of labour migration in its proper historical context ~ before drawing conclusions about the future of the system. In this scholarly pursuit one does not pretend to break a new ground but rather to re-interpret the current literature on migration and establish whether the current pattern of labour migration will change. The research will be based mainly on secondary materials, drawing extensively on published materials, journals and articles.
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  • Date Issued: 1995

Formulating the African National Congress' foreign investment policy in the transition to a post-apartheid South Africa: problems, pressures and constraints

  • Authors: Carim, Xavier
  • Date: 1995
  • Subjects: Investments, Foreign -- South Africa , Political stability -- South Africa , African National Congress -- Foreign economic relations , South Africa -- Foreign economic relations , South Africa -- Economic policy , South Africa -- Economic conditions -- 1991-
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:2764 , http://hdl.handle.net/10962/d1002974 , Investments, Foreign -- South Africa , Political stability -- South Africa , African National Congress -- Foreign economic relations , South Africa -- Foreign economic relations , South Africa -- Economic policy , South Africa -- Economic conditions -- 1991-
  • Description: This study examines the wide-ranging and critical factors which have impacted on the African National Congress' (ANC) emerging foreign investment policy. It identifies and analyses the matrix of political and socio-economic factors which have combined at global and national levels to shape ANC policy perspectives towards foreign direct investment (FDI). In so doing, the study adopts an eclectic theoretical and methodological approach. It draws on various theoretical traditions to propose a framework that is heuristic and contingent, rather than axiomatic. With regard to foreign investment, in particular, it recommends a theoretical pluralism emphasising 'engagement' through praxis and sound political (state) action. The study argues that the ANC has reconsidered many of its basic assumptions on the nature of the post-apartheid economy and discusses the reasons for those shifts. The reasons include, in particular, global political and economic trends and the balance of forces in South Africa. These have combined to ensure the ANC's broad acceptance of an 'open-door policy' towards FDI so long as it occurs on terms not inconsistent with national objectives. The emerging policy sees the state playing an active role in encouraging and guiding FDI to specific areas and sectors supportive of broad-based development. Foreign investors will be encouraged to form joint ventures with emerging black businesses and agree to foster training, skills development and affirmative action. Harnessing the benefits of FDI will be important for the success of wider strategies designed to place the economy on a firmer, more sustainable growth path.
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  • Date Issued: 1995

Foundation declaration

  • Authors: NEDLAC
  • Date: 1995
  • Subjects: NEDLAC
  • Language: English
  • Type: text
  • Identifier: http://hdl.handle.net/10962/151665 , vital:39158
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  • Date Issued: 1995

Function of a cloned polyphenolase in organic synthesis

  • Authors: Naidoo, Michael Joseph
  • Date: 1995
  • Subjects: Polyphenols , Catechol , Streptomacyes , Organic compounds -- Synthesis , Mutagenesis
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4042 , http://hdl.handle.net/10962/d1004103 , Polyphenols , Catechol , Streptomacyes , Organic compounds -- Synthesis , Mutagenesis
  • Description: The enzyme polyphenolase, which catalyses the oxidation of phenols to catechols and subsequently dehydrogenates these to o-quinones, is widely distributed in nature. The multicopy plasmid vector pIJ702 contains a mel gene from Streptomyces antibioticus, that codes for the production of a polyphenol oxidase. The plasmid was isolated from Streptomyces lividans 66pIJ702 and subjected to a variety of mutagenic treatments in order to establish a structurefunction relationship for the polyphenolase enzymes. An attempt was made to engineer the polyphenolase enzyme by localized random mutagenesis in vitro of the mel gene on pIJ702, in order to alter properties like productivity, activity and substrate specificity. It was hoped to alter the amino acid sequence of the active site of the enzyme in order to facilitate catalysis in an organic environment. The plasmid was subsequently transformed into a plasmid-free Streptomyces strain, and enzyme production was carried out in batch culture systems, in order to determine the effect of the height treatment, and to isolate and propagate functional polyphenolase mutants for organic synthesis.
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  • Date Issued: 1995

Fuzzy ideals in commutative rings

  • Authors: Sekaran, Rajakrishnar
  • Date: 1995
  • Subjects: Commutative rings , Fuzzy algebra
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5407 , http://hdl.handle.net/10962/d1005221 , Commutative rings , Fuzzy algebra
  • Description: In this thesis, we are concerned with various aspects of fuzzy ideals of commutative rings. The central theorem is that of primary decomposition of a fuzzy ideal as an intersection of fuzzy primary ideals in a commutative Noetherian ring. We establish the existence and the two uniqueness theorems of primary decomposition of any fuzzy ideal with membership value 1 at the zero element. In proving this central result, we build up the necessary tools such as fuzzy primary ideals and the related concept of fuzzy maximal ideals, fuzzy prime ideals and fuzzy radicals. Another approach explores various characterizations of fuzzy ideals, namely, generation and level cuts of fuzzy ideals, relation between fuzzy ideals, congruences and quotient fuzzy rings. We also tie up several authors' seemingly different definitions of fuzzy prime, primary, semiprimary and fuzzy radicals available in the literature and show some of their equivalences and implications, providing counter-examples where certain implications fail.
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  • Date Issued: 1995

Gender, households and environmental changes in informal settlements in the Eastern Cape Province, South Africa

Geochemical exploration in calcrete terrains

  • Authors: Krug, Mark Alan
  • Date: 1995 , 2013-10-02
  • Subjects: Duricrusts , Silcrete , Geochemical prospecting
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5026 , http://hdl.handle.net/10962/d1006891 , Duricrusts , Silcrete , Geochemical prospecting
  • Description: This work takes a look at some of the literature on calcretes and especially the problem of geochemical exploration in calcrete terrains. The conclusion that will be reached is that exploration in calcrete terrains is not futile and that provided the explorationist is aware of the types of calcrete and their genetic implications calcrete can be used as a sampling medium and anomalies can be detected through calcrete (p.1.) , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
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  • Date Issued: 1995

Geological characteristics of selected disseminated sediment-hosted gold deposits in Nevada, U.S.A. : in search of an exploration model

  • Authors: Skead, Michael Bethel
  • Date: 1995 , 2013-10-07
  • Subjects: Gold ores -- Geology -- Nevada
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5036 , http://hdl.handle.net/10962/d1007414 , Gold ores -- Geology -- Nevada
  • Description: Sediment-hosted disseminated gold deposits in Nevada, western United States are major gold sources and contain reserves in excess of 1 500 metric tons of gold (Percival et aI., 1988). Discovery of these deposit types continues at a pace, with Placer Dome announcing a mojor discovery, Pipeline, to the south of the Gold Acres Mine, along the Battle Mountain - Eureka Trend in 1994 (The Northern Miner, 1994). Host sediments favoured for disseminated gold mineralisation are thinly bedded silty limestones , carbonate debris flows and to a lesser extent shale, chert and sandstone. The distribution of mineralisation is controlled essentially by the intersection of high-angle faults, which acted as conduits for hydrothermal fluids, with favourable host lithologies, anticlines, low-angle faults and other high-angle faults. Geochemical signature for these deposits is simple being Au, Ag, As, Sb, Hg, Tl, Te, F and Ba, but individual element concentrations vary greatly between and within deposits. Age of mineralisation is cause for considerable debate, and ages ranging between isotopic dates of approximately 117 Ma to early to mid-Tertiary (30-40 Ma) are proposed. Most of these deposits are situated along three major trends namely the Carlin, Battle Mountain - Eureka and Getchell trends. The Battle Mountain - Eureka trend and, to a lesser extent the Carlin trend, are defined by major linear aeromagnetic and gravity anomalies , which are believed to reflect deep-seated structures. Most deposits are hosted in autochthonous Devonian, thinly bedded, silty limestones that occur as windows through what is believed to be allochthonous Ordovician siliciclastic sediments, which were transported from west to east along the Roberts Mountains thrust during the late-Devonian Antler Orogeny. However, recent fossil dating of what were thought to be Ordivician siliciclastic sediments, gives a Devonian age. This questions the age of Ordivician sediments at the other deposits and the interpretation of the structural windows in which deposits are located. Fault-bounded, proximal, carbonate debris-flow breccias are now recognised as a major host to mineralisation. These debris flow breccias, together with interbedded carbonate and siliciclastic sediments, carbonaceous sediments and soft sediment deformation are all characteristics of lithologies in pull-apart basins which develop along a major strike slip faults. It is proposed that sediment-hosted disseminated gold mineralisation is controlled by the distribution of deep-seated long-lived, predominantly right-lateral strike-slip faults. It is along these strike-slip faults that syn-sedimentary pull-apart basins developed, within which sediments favoured by epigenetic gold mineralisation were deposited. These pull-apart basins were then overprinted by post-depositional extensional structures, such as negative flower structures. Igneous intrusions and hydrothermal cells have exploited these extensional structures in both compressional and extensional regional tectonic regimes. This model explains the characteristics of the host sediment at many of the deposits, the spatial relationship between igneous intrusion and mineralisation, spanning the period Cretaceous through to mid-Tertiary, the distribution of deposits as districts along major regional trends and why hydrothermal activity is noted between deposit districts but with no complementary mineralisation. Mineralisation is controlled predominantly by high angle structures and although the recent age for mineralisation at the Betze/Post deposit is ~ 117 Ma (Arehart et aI., 1993a), placing it in the compressional Sevier Orogeny, these high-angle structures would be developed within local extensional tectonic domains as described above. This model can, and should, be applied to other areas of the world where similar geological features exist. In exploring for these deposits in Nevada the distribution of Ordovician siliciclastic sediments should be reviewed, especially where spatially associated with deep regional structures. Ordovician sediments have historically been regarded as unfavourable, hence large areas for potential exploration have been ignored but with new ages for these sediments this opens large areas for potential discoveries. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
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  • Date Issued: 1995

Howison's Poort, 6 km SW of Grahamstown, Albany

HPLC analysis and pharmacokinetics of cyclizine

  • Authors: Walker, Roderick Bryan
  • Date: 1995
  • Subjects: High performance liquid chromatography Piperazine Pharmacokinetics
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:3801 , http://hdl.handle.net/10962/d1003279
  • Description: The investigations detailed in this dissertation have been conducted to address the paucity of pharmacokinetic information, in published literature, pertaining to cyclizine. The areas of investigation have included the selective quantitation of both cyclizine and its demethylated metabolite, norcyclizine in serum and urine, assessment of stability of both compounds in stored biological samples, dosage form analysis, dissolution rate testing of tablets, and bioavailability and pharmacokinetics following administration of an intravenous solution, and tablets to humans. High-performance liquid chromatography (HPLC) was used as the main analytical technique throughout these studies. An original HPLC method employing ultraviolet detection with a limit of quantitation of 5μg/ℓ was developed for the determination of cyclizine in serum and both cyclizine and norcyclizine in urine, Solid-phase extraction using extraction columns packed with reversed-phase C18 material, and followed by a simple phase-separation step proved successful for the accurate and precise isolation of the compounds. The validated method was applied to the analysis of serum and urine samples from a pilot study in which a single volunteer was administered 50mg of cyclizine hydrochloride. Several samples collected during the pilot study revealed the presence of both drug and metabolite in concentrations below the limit of detection. In order to improve the selectivity and sensitivity of the analytical method an HPLC method with electrochemical detection operating in the "oxidative-screen" mode was developed. The solid-phase extraction procedure was modified slightly and the method found to be precise, accurate, selective and highly sensitive with a limit of quantitation of Iμg/g/l for both cyclizine and norcyclizine in both serum and urine. This method was applied to the determination of both compounds after intravenous and oral administration of cyclizine to humans. HPLC with electrochemical detection was used for the analysis of samples collected during dissolution studies on the batch of tablets used for pharmacokinetic studies. In addition, this method was used to assess content uniformity of the tablets and of samples from the batch of intravenous ampoules of cyclizine lactate. Dissolution studies showed that all tablets tested passed the compendial specifications for cyclizine. Content uniformity assessment revealed that within-batch uniformity existed for both the tablets and ampoules and, therefore, variations in pharmacokinetic parameters for the drug would more than likely be as a result of inter- and intra-individual variability within the subject population. Pharmacokinetic information for cyclizine was obtained following administration of an intravenous bolus dose of cyclizine lactate as a solution, oral administration of cyclizine hydrochloride as a single dose of 50mg and as fixed multiple doses of 50mg every 8 hours for five days. Further information was acquired following administration of single doses of 100mg and 150mg cyclizine hydrochloride. Data collected from these studies were evaluated using both compartmental and non-compartmental techniques. Cyclizine was rapidly absorbed following oral administration with mean kₐ = 1.54 hr⁻¹ and was found to have an absolute bioavailability (F) of 0.47. The presence of norcyclizine in serum following oral and not intravenous dosing suggests cyclizine is susceptible to "first-pass" metabolism in either the gut wall or the I iver. Mean ClTOT determined following the intravenous dose was 0.865 ℓ/hr/kg. The mean ClTOT of 0.823 ℓ/hr/kg calculated following oral dosing, using a unique value of F for each subject compared favourahly with that obtained following intravenous dosing. Renal clearance of cyclizine is negligihle indicating that non-renal routes of elimination account for the majority of removal of cyclizine form the body. Cyclizine is extensively distributed and the mean Vz following an intravenous dose was 16.70 ℓ/kg. This value is lower than that calculated from all oral studies from which the mean Vz was determined to be 25.74 ℓ/kg. Cyclizine is eliminated slowly with a mean elimination t½ = 20.11 hours. Cyclizine dose not appear to follow dosedependent kinetics and therefore, inability to predict steady state levels are more than likely due to accumulation as a result of frequent dosing rather than saturation of elimination mechanisms. Modelling of intravenous data to one-compartment (lBCM), two-compartment (2BCM) and threecompartment models indicated that the pharmacokinetics of cyclizine can be adequately described by a 3BCM. The drug is rapidly distributed into a "shallow" peripheral compartment (α = 9.44 hr⁻¹ , and k₂₁ = 2.09 hr⁻¹ ), and slowly distributed to the "deep" peripheral compartment (β = 0.451 hr⁻¹ and k₃₁ = 0.120 hr⁻¹ ). Modelling of all oral data indicated that a 2BCM best described the pharmacokinetics of the drug, however, distribution to the peripheral compartment is not as rapid as to the "shallow" peripheral compartment following the intravenous dose. Mean distribution parameters were α = 0.64 hr⁻¹1 and, k₂₁ = 0.39 hr⁻¹. Mean CITOT following intravenous dosing of 0.70 ℓ/hr/kg was similar to the mean CIToT of 0.73 ℓ/hr/kg determined after oral dosing. The mean distribution volume at steady state determined following intravenous dosing (17.78 ℓ/kg) was lower than that obtained from the oral studies (25.52 ℓ/kg). The mean terminal elimination half-lives calculated for cyclizine following fitting of intravenous and oral data was 25.09 hours. In general, mean pharmacokinetic parameters calculated following titting of data to a 2BCM after oral administration correlate closely with those calculated using non-compartmental techniques. However, the pharmacokinetics following intravenous dosing are better described by a 3BCM and a close correlation between parameters estimated using noncompartmental techniques and compartmental techniques is evident when a 3BCM model is used.
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  • Date Issued: 1995

Hydroclimatic trends, sediment sources and geomorphic response in the Bell River catchment, eastern Cape Drakensberg, South Africa

  • Authors: Dollar, Evan S J , Rowntree, Kate M
  • Date: 1995
  • Language: English
  • Type: Article
  • Identifier: vital:6677 , http://hdl.handle.net/10962/d1006655
  • Description: The Bell River in the Eastern Cape Drakensberg of South Africa has shown recent signs of channel instability as evidenced by avulsion, sinuosity reductions, gradient steepening and general channel instability. Analysis of rainfall data did not provide evidence for progressive long term change in rainfall pattern for the catchment. However, annual and seasonal rainfall cycles with variance peaks every 16-19 years were found, from which it can be inferred that flood events following years of below average rainfall may cross the threshold limit for channel stability. Channel instability is often followed by a major flood event after sustained low rainfall periods, a sequence referred to as the Flood and Drought Dominated Regimes by Warner (1987). Evidence presented also indicates an increase in catchment erosion in the past century with attendant sediment production increases to the channel. This may be due to catchment land use and management practices (following settlement by commercial farmers) superimposed on long term climatic changes. The conclusions are that catchment and channel processes are inseparable, and that disequilibrium in the catchment will be transferred to the channel.
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  • Date Issued: 1995

In defence of freedom

  • Authors: NUM
  • Date: 1995
  • Subjects: NUM
  • Language: English
  • Type: text
  • Identifier: http://hdl.handle.net/10962/149565 , vital:38864
  • Description: This book was produced to respond to questions asked by our members during the president’s national RDP mass education tour. It covers our struggle history from as early as 1652 up until the time when Nelson Mandela was inaugurated the first president of a democratic South Africa. The book also attempts to assist comrades to understand what the RDP is and find ways of rebuilding our country after the hard years of apartheid. Workers, particularly from the mining industry will be able to use this book in understanding how their contribution will assist in creating jobs, building more houses etc. We would like you to read this book over and over again and discuss the content with comrades in your branch. The committee will appriaciate any suggestions that you may come up with.
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  • Date Issued: 1995

In vivo/in vitro assessments of topical hydrocortisone availability: correlation between blanching assay and laboratory cell experiments

  • Authors: Smith, Eric W , Haigh, John M
  • Date: 1995
  • Language: English
  • Type: Book chapter
  • Identifier: vital:6438 , http://hdl.handle.net/10962/d1006624
  • Description: From introduction: Topical corticosteroids are still the most widely used drugs in the treatment of dermatological conditions. Early corticosteroid dosage forms consisted of simple creams or ointments where more emphasis was placed on the potency of the drug molecule than on the intrinsic delivery potential of the vehicle. More recently, the effect that the composition of the semisolid base has on the extent of drug delivery has been researched to a much greater extent. These advances in the science of dosage form design have necessitated the refinement of precise and accurate methods for testing the drug delivery efficacies of the developed products. Obviously, the best method for the assessment of the effectiveness of corticosteroid formulations is in a therapeutic situation. Clinical trials, however, are fraught with methodological problems that make duplication of a trial impossible. Alternatively, a number of pharmacological models4 exist for this type of assessment, but it is often problematic to obtain correlation with the true dermatological conditions. The human skin blanching assay is one of the most reliable and reproducible of the ill vivo methods available for the assessment of topical corticosteroid formulations. The skin whitening (blanching or vasoconstriction) side-effect that follows corticosteroid application was first utilized in 1962 as a measure of the percutaneous absorption of corticosteroids from topical formulations. Optimization of this initial procedure7.s has produced a reliable and precise bioassay methodology for the assessment of the efficacy of topical corticosteroid formulations. One criticism of this assay has been the subjective nature of the observation procedure. Although these points have repeatedly been addressed in the literature, it has been suggested that it would be beneficial to have some ill vitro penetration data to supplement ill vivo observations, as this would strengthen the assessment of the topical equivalence of similar delivery formulations. With this objective in mind, a comparison of hydrocortisone release from two proprietary cream formulations was compared by in vivo and ill vitro techniques to determine if any correlation could be established between the methodologies.
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  • Date Issued: 1995

Influence of macro- versus microcooling on the physiological and psychological performance of the human operator

  • Authors: Heyns, Gerhardus Johannes
  • Date: 1995
  • Subjects: Cold -- Physiological effect , Temperature -- Physiological effect , Body temperature -- Regulation , Heat -- Physiological effect
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:5167 , http://hdl.handle.net/10962/d1016247
  • Description: This study evaluated the effect of a macro- versus a microcooling system on the cognitive, psychomotor and physiological performance of human operators. Male subjects (n = 24) were acclimatized for four days and then subjected to three different environmental conditions: hot ambient (40°C; 40% RH), microcooling and macrocooling. Each environmental condition was repeated twice; once under a rest condition and once while simulating a physical workload of 40 W. Four performance tests (reasoning, eye-hand coordination, memory, reaction time) were conducted once every hour for four hours. Five physiological measurements, viz rectal temperature, skin temperature, heart rate, total sweat loss and sweat rate, were taken. A significant difference existed between the physiological responses under the hot ambient condition and both cooling conditions. For all five physiological parameters he human operator benefitted substantially whatever the cooling condition. The psychological performance results indicated a greater benefit under the cooling conditions, though various external factors may have influenced responses. User perception showed that macrocooling was perceived to be the optimal method of cooling. The results showed that there was no difference in the extent to which both rectal temperature and heart rate (for rest and work conditions) decreased over the 4-hour study period with micro- and macrocooling. In the baseline hot environment both increase. Sweat rate was lowest when resting or working in a microcooled environment and at its highest in the hot baseline environment. Mean skin temperature was lowest (for rest and work conditions) with microcooling and highest in the hot baseline environment. Reaction time and memory/attention were the same under all three environmental conditions. Eye-hand coordination was better with cooling than without, but did not differ between the two cooling conditions. Reasoning ability was poorest under the hot baseline condition and best in the macrocooled environment. User perception showed that the subjects found macrocooling highly acceptable. Microcooling was found to be uncomfortable, particularly because cold air (18 - 21°C) entered the jacket at one point which caused numbness of the skin at that point. Jackets did not always fit subjects well and the umbilical cord restricted free movement.
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  • Date Issued: 1995

Insect herbivores associated with indigenous species of Solanum (Solanaceae) in the Transvaal, South Africa, and in Namibia

  • Authors: Olckers, T , Hulley, Patrick E , Hill, Martin P
  • Date: 1995
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/451440 , vital:75049 , https://hdl.handle.net/10520/AJA10213589_108
  • Description: Several indigenous Solanum (Solanaceae) species were surveyed in the Transvaal and Namibia as part of a broader study of the insect herbivores associated with indigenous, as well as weedy and cultivated exotic, solanurns in southern Africa. Insects were collected on three Solanum species in the Transvaal and on 10 in Namibia. Solanum panduriforme E. Mey. and S. incanum L. were abundant in both regions, while S. capense L. was the most common species in Namibia. These three Solanum species supported an abundance of insect herbivores, which included many oligophages found on solanurns in other regions of South Africa. Most of the Solanum insect species were found on a wide range of host plants, in a variety of habitats and under various climatic conditions.
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  • Date Issued: 1995

Insect herbivores associated with Senecio pterophorus and Senecio inaequidens at Butterworth, South Africa

  • Authors: Muwanga-Zake, Johnnie Wycliffe Frank
  • Date: 1995
  • Subjects: Senecio -- South Africa -- Eastern Cape -- Butterworth Insect-plant relationships -- South Africa -- Eastern Cape -- Butterworth Insects -- South Africa -- Eastern Cape -- Butterworth -- Host plants Insects -- South Africa -- Eastern Cape -- Butterworth -- Food Lixus -- biology Insect-plant relationships
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5716 , http://hdl.handle.net/10962/d1005402
  • Description: This study lists and compares insect herbivores of Senecio inaequidens and of Senecio pterophorus around Butterworth by 18 Tables and 38 Figures. The two plant species are widely distributed around Southern Africa. Samples were taken during a month of each of the four main seasons of the year, which in Butterworth did not show much difference in temperature. The two plant species shared generalist insect herbivores most of which were also on other surrounding plant species. The population of most of the herbivores was affected by the seasons while the two plant species were not seasonal, thus the correlation between insect herbivores and the two plant species was not significant. The heavier, and apparently chemically protected species, Senecio pterophorus, accommodated borers and supported a wider variety of but fewer individual insects. Senecio pterophorus could be having more defences but had more serious herbivores. There were no serious insect herbivores that could control the abundance of the two plant species around Butterworth. Anatomical differences between S. pterophorus and S. inaequidens could be highlighted by the kind and number of insect herbivores found upon them. Similarities were more difficult to identify through studying their insect herbivores. The biology of one serious weed, Lixus sp., on Senecio pterophorus was studied in more detail. The life cycle of the weevil was found to be synchronised with that of the host. This weevil shared the stems with other species of weevils with no indication of competition.
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  • Date Issued: 1995

Interacting with Shakespeare's figurative language: a project in materials development for the L2 classroom

  • Authors: Lenahan, Patrick
  • Date: 1995
  • Subjects: Shakespeare, William, 1564-1616 -- Language Shakespeare, William, 1564-1616 -- Study and teaching English literature -- Study and teaching -- South Africa -- Foreign speakers English language -- Study and teaching -- South Africa -- Foreign speakers
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1581 , http://hdl.handle.net/10962/d1003463
  • Description: This project arises from recent initiatives aimed at transforming Shakespeare studies in South African high schools, so as to make those studies more learner-centred and interactive, as well as a more useful communicative language-learning experience for second-language (L2) students. It is this interactive methodology that the present project seeks to extend to the relatively neglected area of Shakespeare's figurative language. Drawing on schema theory and response-based approaches to literature teaching, the project shows that figurative language is especially conducive to interactive treatment, whereby students might be encouraged to make sense of metaphors and similes out of their "background knowledge". Guidelines are indicated for putting this into practice in the L2 classroom; and on the basis of these guidelines, materials are developed for an interactive approach to Shakespeare's figurative language. The central phase in this development process involves trying out the materials in five African high schools and then analysing the data collected from them. The classroom try-outs were profitable in so far as they raised issues that had been overlooked in the earlier, theoretical, stage of the development process. A good overall response to the materials' learner-centred approach was indicated, although students experienced difficulties with certain essential tasks. Most seriously, while the materials were successful in accessing students' background knowledge in the form of associations, they were less successful in getting students to use this knowiedge in interpreting metaphors for themselves. Reasons for this feature, and others, are considered and solutions posited. Recommendations for implementing the materials in a larger teaching programme are made.
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  • Date Issued: 1995

Intercultural communication on a passenger aircraft flight deck: a qualitative study set in the context of South African corporate affirmative action policy

  • Authors: Waite, Michele Jeannette
  • Date: 1995
  • Subjects: ‎Intercultural communication South Africa , ‎Language and culture South Africa , ‎Communication and culture South Africa , ‎Affirmative action programs South Africa , Air pilots South Africa Language , ‎Flight crews South Africa Language , ‎
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:3082 , http://hdl.handle.net/10962/d1002591
  • Description: The recent emphasis on Affirmative Action policies in South African corporations has illuminated the issue of cultural diversity in organizations and the difficulties arising from this transition and change. One such difficulty is the problem of intercultural communication where miscommunication can have life-threatening consequences. This problem is particularly critical in the operational environment of the passenger aircraft flight deck where small group factors, as well as intercultural issues must be taken into account. In this thesis the problem of intercultural communication in such contexts as a consequence of Affirmative Action is examined. The data for this thesis comprises the communication of five culturally diverse flight crews. A multi-method was used for the gathering and analysis of this data. This involved the use of video-taped flight simulator sessions, and personal interviews with each crew member. The subjects themselves were involved in identifying key communication problems from the video and interpretation of the data. Three levels of analysis were used in the interpretation of the findings - the individual, the group and the organization. The factors which affected communication at each level in the small, culturally diverse group are highlighted. Furthermore, factors which influence the climate in which communication takes place are also considered. The implications for Affirmative Action are discussed.
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  • Date Issued: 1995
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