List of Titles

Interaction of serotonin and melatonin with sodium, potassium, calcium, lithium and aluminium

- Lack, Barbara, Daya, Santy, Nyokong, Tebello

Authors: Lack, Barbara , Daya, Santy , Nyokong, Tebello
Date: 2001
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/291553 , vital:56886 , xlink:href="https://doi.org/10.1034/j.1600-079x.2001.310202.x"
Description: In the present study, we investigated the ability of serotonin and melatonin to bind metals that occur naturally in the brain. An electrochemical technique called adsorptive cathodic stripping voltammetry (AdCSV) was employed to study the metal–serotonin or metal–melatonin interactions. The results show that both serotonin and melatonin form stable complexes with lithium and potassium, with serotonin favouring lithium over potassium, and melatonin favouring potassium over lithium. Coordination between either serotonin or melatonin and calcium was not favoured. The stability of the complexes formed between serotonin and the metals decreased with the metals as follows: Li+>K+>Al3+>Na+>Ca2+. The trend for melatonin–metal complexes was K+>Li+>Na+>Al3+>Ca2+. The binding and stable complex formation between both ligands, serotonin and melatonin with lithium, potassium and sodium is of biological importance. The binding of serotonin to lithium could provide an explanation for the therapeutic effects of lithium in depression treatment, whereas the binding of aluminium by melatonin could provide insight into the role of this element in the aetiology of Alzheimer's disease.
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Date Issued: 2001

Investigations to determine the long-term sustainable yield of the Karoo aquifer and the sustained availability of groundwater for small-scale irrigation projects, in Dendera area, Kwekwe District - Zimbabwe

- Njanike, Joseph Tendayi

Authors: Njanike, Joseph Tendayi
Date: 2001
Subjects: Groundwater , Irrigation -- Equipement and supplies , Irrigation -- Kwekwe (Zimbabwe)
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:5093 , http://hdl.handle.net/10962/d1020853
Description: In this thesis the long-term sustainable yield of the Karoo sediment aquifer unit occurring in Dendera area of Kwekwe District is investigated, with the object of providing quantitative data on the sustained availability of groundwater for small-scale irrigation projects. Archaean Basement Schists and Pre-Cambrian gneissic granites, the Basement Complex rocks, underlie the entire study area. Overlying these are Upper Karoo sediments. Aeolian Kalahari sands unconformably mantle higher interfluves, while redistributed sands occur along valleys of major rivers and streams. The Karoo sediments, which predominantly consist of loosely cemented, fine- to medium-grained sandstone alternating with red siltstone and mudstone, constitute the main aquifer. The thickness of the Karoo sediment unit ranges from 30m to 80m. The hydraulic parameters of the Karoo sediment aquifer were characterised in the field by constant discharge pumping tests and slug tests. Pumping tests indicated unconfined conditions and thus the Neuman's method of analysis has been used. Transmissivities from pumping tests are within the range 4.7 m²/d to 13.6 m²/d with an average of 8.9m²/d. The low transmissivities seem to be a major limiting factor in the exploitation of the groundwater resources. Thus the sustainable borehole yields tend to be small, mean values ranging from 33 m²/d to 253 m²/d. Specific yield could not be determined from the pumping tests due to the lack of observation boreholes. Low chemical concentrations render the water suitable for irrigation of all crops, while neither total nor any individual concentrations present health hazards to human or livestock. An average recharge value of 47.7 mm/y was inferred from water table fluctuation method. Chloride mass balance technique in the same area indicates recharge value in the order of 67.4 mm/y. Because the chloride mass balance gives a long-term mean annual recharge, the recharge figure of 67.4 mm/y was adopted for the study area. Based on the abstractable proportion of recharge, the sustainably exploitable volume of groundwater of the order of 2.68 x 10⁷ m³/y was established. This volume is more than 100 times the estimated current demand for groundwater (1.35 x 10⁵ m³/d), implying that there are large volumes of surplus water, which can be utilised for irrigation.
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Date Issued: 2001

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It's the training that did it: a primer for media trainers to assess their impact

- Berger, Guy

Authors: Berger, Guy
Date: 2001
Language: English
Type: Text
Identifier: vital:536 , http://hdl.handle.net/10962/d1008555
Description: To improve journalism, media trainers need information about what’s working and what needs work in the courses they deliver. This means assessing the impact of this training – as it affects attitudes, information, skills and results in the workplace. To isolate the role that training plays, research and evaluation have to take place long before a course begins and continue till long after. This booklet explains the complexities involved, and it provides the tools for trainers to devise usable strategies to assess the impact of their work. The author critically draws from extensive management training literature, and produces a revised theory that he applies to the unique enterprise of journalism training and its assessment.
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Date Issued: 2001

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Journey

- Berold, Robert

Authors: Berold, Robert
Date: 2001
Subjects: To be catalogued
Language: English
Type: text , poem
Identifier: http://hdl.handle.net/10962/462189 , vital:76279 , ISBN 0028-4459 , https://journals.co.za/doi/epdf/10.10520/AJA00284459_563
Description: New Coin is one of South Africa's most established and influential poetry journals. It publishes poetry, and poetry-related reviews, commentary and interviews. New Coin places a particular emphasis on evolving forms and experimental use of the English language in poetry in the South African context. In this sense it has traced the most exciting trends and currents in contemporary poetry in South Africa for a decade of more. The journal is published twice a year in June and December by the Institute for the Study of English in Africa (ISEA), Rhodes University.
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Date Issued: 2001

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KwaZakele: the politics of transition in South Africa: an Eastern Cape case study

- Cherry, Janet Mary

Authors: Cherry, Janet Mary
Date: 2001
Subjects: South Africa -- Transition to democracy Democracy -- South Africa -- Eastern Cape Eastern Cape (South Africa) -- Politics and government Port Elizabeth region (South Africa) -- Political aspects
Language: English
Type: Thesis , Doctoral , PhD
Identifier: vital:2766 , http://hdl.handle.net/10962/d1002976
Description: This thesis examines the transition to democracy in South Africa through the use of case study methodology. The nature of political participation and the form of democracy to emerge at the end of the transition process are the central subjects of inquiry. They are examined through an in-depth study of the African community of Kwazakele, a township in the Nelson Mandela metropolitan area in the Eastern Cape province of South Africa. The study covers the period from 1993 to 2000, and uses as a primary data source five surveys conducted among residents of Kwazakele during that period. The emphasis of the study lies on the experience of political participation of ‘ordinary people’ – in particular, the African urban working-class in South Africa who make up the core support base for the governing African National Congress. The primary findings of the thesis are as follows: * Representative democracy has been successfully consolidated in the community under study. * Levels of political participation by urban Africans in the Eastern Cape are consistently high, both in formal political institutions (primarily elections) and in institutions of civil society. * As politics has normalised at the end of the transition period, forms of direct democratic participation have declined. * Despite the structural constraints on development, there is still potential for a high level of participation by citizens in effecting change at local level. * Drawing on the experience of ordinary people in structures of direct democracy, this level of participation can result in a deeper and stronger form of democracy than exists in many established representative democracies.
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Date Issued: 2001

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Laboratory and occupation-simulating isokinetic and psychophysical responses of military personnel

- James, Jonathan Peter

Authors: James, Jonathan Peter
Date: 2001
Subjects: Isokinetic exercise , Soldiers -- South Africa
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:5126 , http://hdl.handle.net/10962/d1005204 , Isokinetic exercise , Soldiers -- South Africa
Description: The present study assessed the isokinetic responses of male military personnel(N=42). The study aimed to evaluate the strength capabilities of South African infantrymen and establish benchmark data on a population not previously tested. “Work-simulation” packages have not been widely exploited and this study further aimed to approximate how effectively occupation simulating tasks could identify the capabilities of soldiers. Testing was carried out using a CYBEX 6000 isokinetic dynamometer and involved six laboratory tests (LTs) and four occupation-simulating tests (OSTs). Subjects were required to complete two testing sessions with the order of tests randomized. The LTs consisted of ankle, elbow, hip, knee, shoulder and trunk. In the OSTs, gripping, valve-tightening, wrench-turning and pulling/pushing responses were collected. Slow, medium and fast test speeds were used for each bout. Cardiac responses were measured using heart rate monitoring and perceptual measures assessed using Borg’s (1971) RPE scale. The results of the testing showed significant differences in agonist and antagonist responses at all three testing speeds, the only exception being slow speed trunk values (peak torque). Upper- to lower-extremity ratios highlighted a possible weakness in the elbow flexors group, while correlations between LTs and OSTs highlighted the specificity of strength principle, as poor relationships were observed.
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Date Issued: 2001

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Language policy, symbolic power and the democratic responsibility of the post-apartheid university

- Alexander, Neville

Authors: Alexander, Neville
Date: 2001
Subjects: Academic Freedom -- South Africa Universities and colleges -- South Africa Equality Liberty Education and state -- South Africa Education, Higher -- South Africa
Language: English
Type: text
Identifier: http://hdl.handle.net/10962/696 , vital:19982
Description: Recent articles by John Higgins (1999) and André du Toit (2000), both of the University of Cape Town and a forthcoming article by Roger Southall and Julian Cobbing have contextualised the discussion of this perennial question in both time and place. Du Toit, in particular, has put the cat among the pigeons by querying the relevance in the era of globalisation and the corporatisation of institutions of higher learning, of the classic liberal interpretation of the T.B. Davie formula deriving from the 1950s, i.e., the freedom of "the university" to decide whom to teach, what to teach, how to teach and who should teach. The gist of his argument is that the danger no longer comes from outside the walls of the university, in the guise of the racist apartheid state, for instance. Instead, the threat comes from inside the institutions themselves as the result of the so-called managerial revolution, which is a manifestation of the shift of power from the collegium academicum to the administrative officials, since the curricular and pedagogical, i.e., academic, freedom of the lecturing and research staff is thereby put at risk. He maintains that the manner in which Higgins and others have addressed the question is anachronistic in that the political terrain and the institutional dynamics in which universities operate in post-apartheid South Africa are light years removed from the apartheid university. At the very least, one-quarter of the composite formula, that which refers to "whom to teach" has been rendered irrelevant, since there is no longer any barrier to access to tertiary education, besides those that operate in any "normal" capitalist democracy.
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Date Issued: 2001

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Living in Grahamstown East/Rini: a social indicators report

- Moller, Valerie, Manona, Cecil W, Van Hees, C, Pillay, E, Tobi, A

Authors: Moller, Valerie , Manona, Cecil W , Van Hees, C , Pillay, E , Tobi, A
Date: 2001
Language: English
Type: Book , text
Identifier: vital:540 , http://hdl.handle.net/10962/d1010769
Description: [From the preface]: The ‘Living in Grahamstown East/Rini’ project takes its title from a series of reports on social indicators initiated by Statistics South Africa. The popular series aims to communicate to ordinary people the statistics on living conditions in various parts of the country. The first two booklets in the series, Living in South Africa and Living in Gauteng, were based on survey data for South Africa and Gauteng Province (CSS: 1996; 1997). In similar vein, this booklet presents statistics on living conditions in Grahamstown East/Rini for ready reference by community organisations, local planning and policy-makers, scholars, and the general public. [From the introduction]: This report is intended to serve the needs of information users. The source of information is a representative sample survey of 862 Grahamstown East/Rini households conducted in May 1999. The report serves as a reference work for municipal planners and policymakers, community organisations, and interested citizens. It is hoped that the reported social indicators will be useful for drawing up business plans for community development projects. The information in this report is mainly factual. It is based on self-reports collected from households in Grahamstown East/Rini. In time, the facts contained in this report will date. They will then gain historical value for scholars with an interest in learning "how things were" to compare the situation in Grahamstown East/Rini in 1999 with later developments and changes in living conditions and lifestyles , This was edited by Valerie Møller, with contributions by Cecil W. Manona, Charlotte van Hees, Edmund Pillay and Andile Tobi , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
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Date Issued: 2001

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Magnitudes and temporal sequencing of load kinematics and kinetics for single-handed pulls

- MacKinnon, S N

Authors: MacKinnon, S N
Date: 2001
Language: English
Type: Article
Identifier: vital:6747 , http://hdl.handle.net/10962/d1009327
Description: This paper provides data regarding kinematics and kinetics during single-handed, submaximal pulls about various locations in the frontal plane for three loads (6, 12 and 18% lean body mass). Pulls were executed at two relative heights (elbow and eye) through two parasagittal planes also relative to subject morphology. Results indicate that in most cases load and pull location influence the occurrence of measured kinetic variables within a pull cycle but have little effect on the magnitude of these values. Findings from this study suggest that analyses of kinematic and kinetic movement histories may be required for a better understanding of the mechanical loading profiles upon operators engaged in such manual materials handling activities.
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Date Issued: 2001

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Managing regrowth of an indigenous savanna tree species (Terminalia sericea) for fuelwood: The influence of stump dimensions and post-harvest coppice pruning

- Shackleton, Charlie M

Authors: Shackleton, Charlie M
Date: 2001
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/181672 , vital:43757 , xlink:href="https://doi.org/10.1016/S0961-9534(00)00086-6"
Description: Most African savannas are subjected to harvesting of wood, especially for fuelwood, charcoal and construction timber. A key attribute of the resilience and productivity of savannas is the ability of damaged trees to regrow from the remaining stump. Survival of the cut stem and growth rate of the resultant coppice shoots is influenced by several factors, including size of the tree, cutting height and the root/shoot ratio after felling. Some of these can be manipulated to maximise subsequent regrowth, but this is little understood for most African savanna species. This study investigated the influence of original tree size, height of cut and post-harvest pruning on regrowth of Terminalia sericea. Regrowth was monitored as the number of coppice shoots, the mean coppice shoot length and the cumulative coppice shoot length per cut stump over four growing seasons. There was a positive relationship between cutting height and number of coppice shoots, but height of cut did not significantly affect mean or cumulative coppice shoot length. Larger stems produced more coppice and had greater mean and cumulative coppice shoot lengths than smaller stems. Post-harvest pruning increased the mean shoot length, but not the cumulative shoot length. After four growing seasons mean shoot length for the single shoot pruning treatment (one shoot left) was 54% greater than for the no prune treatment, whilst the double shoot pruning (two shoots left) was 40% greater. Extrapolated harvest intervals for fuelwood poles were 3–4 years for large stems, 4–5 years for medium-sized stems, and 4–9 years for small stems.
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Date Issued: 2001

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Measuring the value of the arts to society: the importance of the value of externalities for lower income and education groups in South Africa

- Snowball, Jeanette D, Antrobus, Geoffrey G

Authors: Snowball, Jeanette D , Antrobus, Geoffrey G
Date: 2001
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/143134 , vital:38204 , https://doi.org/10.1111/j.1813-6982.2001.tb00034.x
Description: Governments in many countries have cut their support of the arts on the grounds that it is the pleasure of the higher income, well educated members of society that they are sponsoring. In the 1980's government support of the arts, even in developed countries, fell by 30 per cent (Throsby 1994). While it is true that many studies have found that arts attenders represent the educated, prosperous minority of society (Morrison and West, 1986; Dobson and West, 1990; Hendon 1990), this paper argues that if the social as well as the more traditional economic measures of the value of the arts are considered, it can be shown that many of the positive externalties provided by the arts accrue to lower income and education groups.
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Date Issued: 2001

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Mentoring and prospects for teacher development - a South African perspective

- Probyn, Margie J, Van der Mescht, Hennie

Authors: Probyn, Margie J , Van der Mescht, Hennie
Date: 2001
Language: English
Type: Conference paper
Identifier: vital:6090 , http://hdl.handle.net/10962/d1009744
Description: School-based mentoring has developed in response to a number of factors pertaining to the pre-service education of student teachers and the in-service professional development of experienced teachers. Traditionally teacher education has consisted of university-based theory with school-based practice, based on an understanding of professional learning as ‘theory into practice’. One of the problems with this model is that theory may come to seem too remote from practice, and that practice appears untheorised by remaining implicit and unproblematised. The one-year teachers’ diploma course offered by the Rhodes University Education Department incorporates a ten-week teaching practice slot. This protracted period has been useful in allowing frequent and consistent contact between university tutors and student teachers, and between mentor teachers and student teachers. Where the system has not been strong is in enabling meaningful collaboration among all three parties. A pilot school-based mentoring programme was thus implemented in 1999, involving English First and Second Language student teachers, the two university tutors and seven mentor teachers. Ongoing evaluative research revealed that the programme was welcomed by all, and that the student teachers in particular gained much in the way of learning to be critically reflexive in a non-threatening environment. However, the research also uncovered areas that need to be developed. Student teachers, for example, need guidance in terms of learning how to talk about teaching; mentor teachers need to develop the confidence and expertise required to open up their practice in a critically constructive context. On the strength of the programme’s success, the Education Department has extended school-based mentoring to all HDE students, and is exploring ways of setting up courses through which other educators (such as EDOs) may receive training in pre- and in-service teacher mentoring.
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Date Issued: 2001

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Monitoring a diagnosis for control of an intelligent machining process

- Van Niekerk, Theo

Authors: Van Niekerk, Theo
Date: 2001
Subjects: Expert systems (Computer science) -- Industrial applications , System design
Language: English
Type: Thesis , Doctoral , DTech (Engineering)
Identifier: vital:10814 , http://hdl.handle.net/10948/70 , Expert systems (Computer science) -- Industrial applications , System design
Description: A multi-level modular control scheme to realize integrated process monitoring, diagnosis and control for intelligent machining is proposed and implemented. PC-based hardware architecture to manipulate machining process cutting parameters, using a PMAC interface card as well as sensing processes performance parameters through sampling, and processing by means of DSP interface cards is presented. Controller hardware, to interface the PC-based PMAC interface card to a machining process for the direct control of speed, feed and depth of cut, is described. Sensors to directly measure on-line process performance parameters, including cutting forces, cutting sound, tool-workpiece vibration, cutting temperature and spindle current are described. The indirect measurement of performance parameter surface roughness and tool wear monitoring, through the use of NF sensor fusion modeling, is described and verified. An object based software architecture, with corresponding user interfaces (using Microsoft Visual C++ Foundation Classes and implemented C++ classes for sending motion control commands to the PMAC and receiving processed on-line sensor data from the DSP) is explained. The software structure indicates all the components necessary for integrating the monitoring, diagnosis and control scheme. C-based software code executed on the DSP for real-time sampling, filtering and FFT processing of sensor signals, is explained. Making use of experimental data and regression analysis, analytical relationships between cutting parameters (independent) and each of the performance parameters (dependent) are obtained and used to simulate the machining process. A fuzzy relation that contains values determined from statistical data (indicating the strength of connection between the independent and dependent variables) is proposed. The fuzzy relation forms the basis of a diagnostic scheme that is able to intelligently determine which independent variable to change when a machining performance parameter exceeds control limits. The intelligent diagnosis scheme is extensively tested using the machining process simulation.
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Date Issued: 2001

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Novel approaches to the synthesis of quinoline derivatives

- Klaas, Phindile Jonathan

Authors: Klaas, Phindile Jonathan
Date: 2001 , 2013-04-26
Subjects: Quinoline--Synthesis
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:4299 , http://hdl.handle.net/10962/d1004751 , Quinoline--Synthesis
Description: The investigation has been concerned with the application of the Baylis-Hillman methodology to the synthesis of quinoline derivatives. An extensive range of novel Baylis-Hillman products has been prepared, typically in moderate to excellent yields, by condensing 2-nitrobenzaldehyde derivatives with various vinyl ketones and acrylic esters in the presence of diazabicyclo[2.2.2]octane (DABCO). Reduction of the nitro group in the Baylis-Hillman products was effected by catalytic hydrogenation in ethanol using a 10% palladium-on-carbon catalyst to afford quinoline, quinoline-N-oxide and quinolone derivatives. In all cases, it is apparent that cyclisation involves exclusive attack of nucleophilic nitrogen at the carbonyl centre, with acrylic ester derivatives affording quinolones and vinyl ketone derivatives affording quinolines and the corresponding quinoline-N-oxides. No products arising from a conjugate addition pathway were observed. The use of stannous chloride as an alternative reagent to effect reductive cyclisation of the Baylis-Hillman products has been explored, and found to favour the formation of 1,2- dihydroquinoline derivatives, with cyclisation occurring via a conjugate addition pathway. Isolation of the products, following work-up of the stannous chloride reactions, however, presented some difficulty. All compounds were characterised by spectroscopic (NMR and IR) and, where appropriate, elemental (high-resolution MS) analysis. Interconversion of the quinoline and quinoline-N-oxide derivatives has been explored and finally achieved in quantitative yields. Reduction of 2,3-dimethylquinoline-N-oxide to the corresponding quinoline was effected using phosphorus tribromide in DMF, and the reverse transformation with meta-chloroperbenzoic acid (MCPBA) in CHCl₃. Application of these methods to mixtures of 2,3-dimethylquinoline and its N-oxide has afforded, selectively, either the quinoline derivative or the corresponding N-oxide. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
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Date Issued: 2001

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NUM Education strategic plan

- NUM

Authors: NUM
Date: 2001
Subjects: Uncatalogued
Language: English
Type: text
Identifier: http://hdl.handle.net/10962/106445 , vital:32652
Description: First we need to ask the obvious question, what is the purpose of a trade union education strategic plan? The answer is as follows,To enable the union to locate its educational concerns and plan its responses with due regard to available resources, and capacity. To ensure that there is a reference point for a thorough on-going assessment of progress. To help articulate a vision for the unions education which inspires and motivates all those concerned. This is critical to the long-term success of our union. Assessing and adopting strategic options requires a vision to help us locate and then analyse both external and internal conditions. It helps us to formulate manageable and realistic strategies to achieve agreed objectives. It helps us to implement our plans with a clear appreciation of our true capacity and to measure outcomes accurately
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Date Issued: 2001

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Nurses' experience of contesting discourses in HIV/AIDS activities in the primary health care setting

- Tutani, Lumka

Authors: Tutani, Lumka
Date: 2001
Subjects: Primary health care , AIDS (Disease) -- Nursing , AIDS (Disease) -- Patients -- Counseling of
Language: English
Type: Thesis , Masters , MA
Identifier: vital:3074 , http://hdl.handle.net/10962/d1002583 , Primary health care , AIDS (Disease) -- Nursing , AIDS (Disease) -- Patients -- Counseling of
Description: This paper explores the experience of nurses who work both as Primary Health Care Providers and counsellors trained in the narrative model of counselling in primary health care settings. Five focus groups were conducted in both Xhosa and English. Discourse analysis was used as a method of analysing the data. Training nurses in the narrative counselling model introduced an alternative discourse, which was experienced as contradicting their usual way of working. Two dominant discourses were the “not knowing” approach, assumed by the narrative model of counselling, and the “knowing” stance, assumed by health education. The institutionalised construction of counselling by doctors and matrons, and their power versus the power of the nurse counsellors was also cited as sources of conflict. Despite the tensions, narrative model of counselling seems to be offering new positions, which may benefit people living with HIV and improve HIV/AIDS activities in the Primary Health Care (PHC) context.
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Date Issued: 2001

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Parasitism of Plutella xylostella (Lepidoptera, Plutellidae): field and laboratory observations

- Waladde, S M, Leutle, M F, Villet, Martin H

Authors: Waladde, S M , Leutle, M F , Villet, Martin H
Date: 2001
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/442239 , vital:73969 , https://doi.org/10.1080/02571862.2001.10634397
Description: Investigations carried out at Alice and its rural environs in the Eastern Cape province of South Africa, showed that parasitoids affecting the diamondback moth Plutella xylostella (L.) (Lepidoptera: Plutellidae) were Cotesia plutellae, Apanteles eriophyes, Diadegma sp., Diadromus collaris, Oomyzus sokolowskii and Hokeria sp. Cotesia plutellae was active all year round and accounted for 30–50% parasitism of P. xylostella. Field experiments using three cabbage cultivars, grown under pesticide-free conditions, indicated that C.plutellae achieved rates of parasitism as high as 90–95% for at least eight months of the year. In winter and early spring parasitism by C. plutellae was less than 30% in the field. This level of parasitism coincided with rising pest density resulting in a pest increase in early spring when C. plutellae appeared unable to control the high pest numbers. Towards the latter part of spring and early summer, C. plutellae parasitism and that of the other parasitoids increased. The possibility of using indigenous parasitoids especially C. plutellae in the management of P. xylostella in this area requires further investigation.
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Date Issued: 2001

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Photochemical studies of tetra-2, 3-pyridinoporphyrazines

- Seotsanyana-Mokhosi, Itumeleng, Kuznetsova, Nina, Nyokong, Tebello

Authors: Seotsanyana-Mokhosi, Itumeleng , Kuznetsova, Nina , Nyokong, Tebello
Date: 2001
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/291580 , vital:56889 , xlink:href="https://doi.org/10.1016/S1010-6030(01)00427-0"
Description: Tetra-2,3-pyridinoporphyrazines and the corresponding water-soluble N,N′,N′′,N′′′-tetramethyl-tetra-2,3-pyridinoporphyrazine complexes, containing central metal atoms; M=Ge, Sn, Si and Zn, were synthesized and their photochemical properties were investigated. The reductive quenching of pyridinoporphyrazines excited states, enhanced relative to phthalocyanines, was considered as the first photochemical step of dyes phototransformation in dimethylformamide (DMF) and dimethylsulfoxide (DMSO) solutions under irradiation with visible light. Efficiency of singlet oxygen photosensitization decreases significantly in the row phthalocyanines, unquaternized, quaternized tetra-2,3-pyridinoporphyrazine metallocomplexes.
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Date Issued: 2001

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