The thermodynamics of solutions and binary liquid mixtures
- Authors: Mercer-Chalmers, June Dawn
- Date: 1993
- Subjects: Thermodynamics Liquids Solution (Chemistry)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4390 , http://hdl.handle.net/10962/d1005055
- Description: The thesis is presented in two parts. In part one, the excess thermodynamic properties have been determined for several binary liquid mixtures, with the aim of testing theories of liquid mixtures. The excess molar enthalpies, Hem, have been determined using an LKB flow microcalorimeter, and the excess molar volumes, Vem, have been determined using an Anton Paar densitometer. The HemS and VemS have been measured at 298.15 K for binary systems involving an alkanol (methanol, ethanol, I-propanol, 2-propanol) mixed with a hydrocarbon (l-hexene, I-heptene, l-octene, I-hexyne, I-heptyne, l-octyne, toluene, mesitylene, 0-, m-, or p-xylene, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane). The results show trends relating to the degree of unsaturation, or size, of component molecules as well as the position of the hydroxyl group on the alkanol. Measurements were also made on mixtures involving an (n-alkane + a pseudo-n-alkane) and ( a cYcloalkane + a pseudo-cycloalkane). Two theories of liquid mixtures were tested in this work. The first theory tested was the theory of Congruency. This theory was tested, by means of a null test, on a novel set of mixtures involving an n-alkane (hexane, heptane, octane, decane, dodecane) + a pseudo-nalkane,and mixtures of a cycloalkane (cyclopentane, cyclohexane, cycloheptane, cyclooctane)+ a pseudo-cycloalkane. Deviations from the theory was less than the experimental error for the (n-alkane + pseudo-n-alkane) mixtures. However, significant deviations were observed for the mixtures of (a cycloalkane + a pseudo-cycloalkane). The second theory tested was the Flory theory, which has been used to predict the excess molar enthalpies and excess molar volumes for the mixtures involving (a 1-alkene, or 1-alkyne, or methyl-substituted benzene) + an alkanol. The results show that the theory does not hold for hydrocarbon mixtures involving an alkanol. In the second part of this thesis, the partial molar volumes, at infinite dilution, of binary solution involving a solid solute (18-crown-6 ether, dibenzo-18-crown-6 ether, dicyclohexanov 18-crown-6 ether, 15-crown-5 ether, or cryptand-222) are determined in various solvents. The results were repeated with a view to determine the volume changes at infinite dilution upon complexation, ΔV∞ of the crown ether or cryptand with a metal halide salt, MX (NaCl, NaI, KCl, KI, CsCl, CsI). The ΔV∞ results were compared with results in the literature for cryptand-222 (c-222) and dibenzo-18-crown-6 ether (B₂CE6) complexed with MX, and the study was extended to include further MX complexes with c-222 and B₂CE6, as well as MX complexes with 15-crown-5 ether and dicyclohexano-18-crown-6 ether. ΔV∞ results were correlated with the Hepler prediction of the electrostriction solvent effect.
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- Date Issued: 1993
The ultrastructure and computer-enhanced digital image analysis of plasmodesmata at the Kranz mesophyll-bundle sheath interface of Themeda triandra var. imberbis (Retz) A. Camus in conventionally-fixed leaf blades
- Authors: Botha, Christiaan E J , Hartley, B J , Cross, Robin H M
- Date: 1993
- Language: English
- Type: Article
- Identifier: vital:6502 , http://hdl.handle.net/10962/d1005925
- Description: The ultrastructure of the plasmodesmata at the Kranz mesophyll-bundle sheath (KMS-BS) interface in Themeda triandra, and the substructures within the plasmodesmata were investigated, using conventionally fixed leaf-blade material, enhanced by the addition of 0.1% tannic acid to the primary fixative. Examination of high-resolution electronmicrographs, and computer-enhanced digital images suggests that these plasmodesmata are complex structures, comprised of helically-arranged particulate material. The electron-dense particles are between 2.5 and 3.0nm in diameter. These particles are specifically associated with the inner face of the inner plasmalemma membrane leaflet, and the outer region of the desmotubule wall. The electron-dense particles are presumably proteinaceous and embedded in a lipid matrix. In the constricted median portion of the KMS-BS plasmodesmata, the space between the desmotubule and the inner plasmalemma membrane leaflet and areas surrounding the proteinaceous particles thereof (the cytoplasmic sleeve) is about 3nm in cross-section, and constitutes what we believe to be the space through which intercellular transport takes place.
- Full Text: false
- Date Issued: 1993
The use of the local environment for teaching geography : a case study in the Umtata administrative area
- Authors: Adonis, Agrinette Nolwandle
- Date: 1993
- Subjects: Geography -- Fieldwork -- Study and teaching Geography -- South Africa -- Study and teaching (Secondary) Black people -- Education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1816 , http://hdl.handle.net/10962/d1003702
- Description: Current theories in geographical education advocate the use of strategies that encourage the pupil to play an active role in learning, thereby making such learning more meaningful and effective. Fieldwork is perceived as one such method. Fieldwork helps pupils acquire and develop understanding of geographical concepts, skills, attitudes and values through their own efforts and involvement. Fieldwork approaches have tended to change with the changing paradigms resulting in the development of approaches that are more pupil and experience oriented. In the South African school geography curricula fieldwork has been explicit since 1985. However, research has shown that in most South African secondary schools fieldwork as a teaching strategy is only applied to a limited extent. Teachers have always used financial constraints and time limitations as explanations for their failure to use fieldwork in teaching geography. This study attempts to demonstrate how the local environment of any school can be used effectively for teaching and learning most aspects of the senior secondary school geography syllabus, thereby alleviating the problems of time and money perceived by teachers as the major constraints inhibiting their use of fieldwork. In order to illustrate the effectiveness of fieldwork in the local environment, this study incorporated an analysis of the current senior secondary school geography syllabus, the identification of potential fieldwork sites in the Umtata District and the development and implementation of three fieldwork units based on three of the sites identified. The analysis of the evaluations of the three fieldwork units by the researcher, the pupils and the non-participant observer revealed that fieldwork conducted in the local environment is highly effective, interesting and rewarding to pupils even when they have no prior experience of fieldwork.
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- Date Issued: 1993
The work of the Reverend James Cameron of the Wesleyan Methodist Missionary Society from 1829 to 1835
- Authors: Van Heerden, Gary Paul
- Date: 1993
- Subjects: Cameron, James, 1800-1875 Wesleyan Methodist Missionary Society Methodist Church of Southern Africa -- History
- Language: English
- Type: Thesis , Masters , MTh
- Identifier: vital:1245 , http://hdl.handle.net/10962/d1009726
- Description: The name James Cameron is not a familiar one. Despite being one of the missionary pioneers of Methodism in southern Africa, serving for more than forty-six years in various districts and being elected as chairman of two of these districts, very few people have ever heard of James Cameron. Barnabas Shaw says of Cameron that he "excelled in preaching the great truths of the gospel, and applying them to the heart of sinners".¹ Whiteside describes Cameron as a "remarkable man ... well read in most things".² W.B. Boyce pays Cameron an even greater tribute: In my day, as a preacher and as a theologian, he was unequalled in South Africa; and I do not think that he was second in these respects to any of his brethren in England.³ Notwithstanding the high esteem in which he was held by prominent peers, Cameron is mentioned only in passing in a few secondary sources, and to date has not been the subject of academic research. The reason for this is not clear. He was well educated, read and wrote extensively, and most of his correspondence has been preserved. Cameron's Journal is very well written, containing some beautiful poetic sections. It is a personal record of a missionary coping with peculiar and difficult circumstances, and a record of how determination, courage and faith enabled Cameron to overcome seemingly insurmountable difficulties. Cameron's recording of his struggles help fill out our understanding of missionaries and their tasks and problems in the nineteenth century. I believe that so important a figure in South African Methodism should be examined and deserves a definitive study. The aim of this thesis has been to provide a reference to his work in the western Cape, possibly to form a basis for closer historical scrutiny. ¹ Shaw 1840:232 ² Whiteside 1906:374 ³ Boyce 1874:179-80.
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- Date Issued: 1993
Thermal decomposition of mixed metal oxalates
- Authors: Coetzee, Anita
- Date: 1993
- Subjects: Oxalates -- Research , Decomposition (Chemistry)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4388 , http://hdl.handle.net/10962/d1005053 , Oxalates -- Research , Decomposition (Chemistry)
- Description: The mixed metal oxalates, FeCu(ox)₂.3H₂0, CoCu(ox)₂.3H₂0, and NiCu(ox)₂.3.5H₂0, [ox = C₂0₄] have been prepared by coprecipitation from solution. The thermal behaviour of these compounds in nitrogen and in oxygen has been examined using thermogravimetry (TG), thermomagnetometry (TM), differential scanning calorimetry (DSC) and evolved gas analysis (EGA), and results are compared with results obtained for Cuox and Mox.yH₂0. The thermal behaviour of the mixed oxalates, MCU(OX)₂.xH₂0, differed from that of the individual metal oxalates, Cuox, Coox.2H₂0, Niox.2H₂0 and Feox.2H₂0. All three mixed oxalates on heating in N₂, first dehydrate and then decompose in at least two overlapping endothermic stages. Both CO and CO₂ were evolved in proportions which varied with the surrounding atmosphere, and from compound to compound, and with extent of reaction of a given compound. The mixed oxalates, MCU(OX)₂.xH₂0, do not show the exothermic behaviour characteristic of Cuox, and reasons for this are discussed. Thermochemical calculations were done and the enthalpies of formation of the hydrates and dehydrated oxalates were determined. It was found that the enthalpy of mixing was very small or within experimental error. X-ray powder diffraction patterns for the individual and mixed oxalates were compared. The pattern for Cuox differs from the patterns obtained for the other oxalates, confirming suggestions that Cuox has a structure different to most other transition metal oxalates. The kinetics of dehydration and decomposition of the mixed oxalates were investigated, using isothermal and programmed temperature TG and DSC experiments. The yield and composition of evolved gases during isothermal decomposition were measured and compared with the enthalpy changes. X-ray photoelectron spectroscopy studies provided some information on the electron environment of the metal atoms in the various oxalates.
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- Date Issued: 1993
Tie Na ka Baramousso
- Authors: Sali Sidibe (composition, lyrics, lead vocal) , Boubacar Kane (djembe) , Aminata Diabate, Fatim Sissoko (backing vocals) , Rakesh Toure (keyboards) , Mamadou Coulibaly (N'Bolon) , Harouna Samake (N'goni) , Zoumana Tereka (Violin) , Samba Dioakite (Balafon) , Sterns Africa label , Samassa Records
- Date: 1993
- Subjects: Popular music--Africa, West , Popular music--Mali--1991-2000 , Africa Mali Bamako f-ml
- Language: Bambara
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/130024 , vital:36365 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC36-04
- Description: Malian neo-traditional vocals set to a unique blend of didai, sigui and sogonikun dance rhythms
- Full Text: false
- Date Issued: 1993
Ultrastructural development in the corpus allatum of the adult worker honey bee
- Authors: Lloyd, Gerry Trevor
- Date: 1993
- Subjects: Bees -- Anatomy , Honeybee
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5792 , http://hdl.handle.net/10962/d1005480 , Bees -- Anatomy , Honeybee
- Description: The ultrastructure of the corpus allatum of the Cape worker honey bee has been examined in a systematic way during the first thirty days of adult life. Corpus allatum size in the Cape worker honey bee shows the age-dependent increase typical of the European worker honey bee, and in the Cape worker bee, the duration of increase is protracted. Analysis of ultrastructural development provides three indicators of metabolic status: mean mitochondrial size, "light and dark" cells, and extracted vacuoles. Significant fluctuations in mean mitochondrial size indicate a cyclical nature of cellular activity. New thought on the nature of "light and dark" cells proves that "dark" cells are almost certainly active in the process of JH biosynthesis, whilst "light" cells are definitely not active in JH biosynthesis. Extracted vacuoles found in corpus allatum cells during this study are thought to be remnants of lipid vacuoles, and the build up in number of these vacuoles is regarded as an indicator of reduced biosynthetic activity. Since the two indicators of decreased JH production ("light" cells and extracted vacuoles) co-exist with smaller mean mitochondrial size, larger mean mitochondrial size is taken as indicating increased levels of JH biosynthesis. Hence, fluctuations in mean mitochondrial size suggest cycles in the levels of JH production in individual corpora allata of the adult worker honey bee.
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- Date Issued: 1993
Union restructuring
- Authors: CWIU
- Date: 1993
- Subjects: CWIU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/178882 , vital:43007
- Description: The idea to restructure the union is not a new one. Political changes in our country compelled almost all the unions to consider the possibilities of restructuring the union and the industry in general. New approaches to Collective Bargaining Strategies came to the fore. The good example of these Bargaining strategies was the NUMSA THREE YEAR BARGAINING STRATEGY (1993). Later in the same year, CWIU also introduced its Bargaining Strategy in the form of five pillars. The common thing about Numsa and CWIU bargaining strategies is that they both failed to deliver and the process of setting up working groups are more complex than expected. The main cause of the tap problem in my view is that the existing union structures are a big deterent to the development and implementation of new bargaining strategies. Our Centralised Bargaining victory and the new LRA will demand major union restructuring if we want to utilise the openings created by these new developments. In this discussion paper, I will focus on how we should restructure our union. In this paper, I am suggesting that the union (CWIU) must be made up of four semi-autonomous departments.
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- Date Issued: 1993
Universities in crisis : a reflection on the African experience
- Authors: Mamdani, Mahmood
- Date: 1993
- Subjects: Academic Freedom -- South Africa
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/672 , vital:19980
- Description: The real point of democratic reform, what I have been calling institutional reform, is not just to change the complexion of researchers, teachers and students, nor just to change the location of research and teaching, to be truly meaning- fill, reform has to lead to a change in the orientation of these activities. Let me take a hypothetical example, one where you succeed in adding more black and female faces to the research and leaching establishment and even to shifting the location of that establishment mainly to historically black universities - say your most advanced medical research facilities come to be located at the University of Fort Hare, with researchers mainly black and female, but the facility is still oriented to proton beam research for special types of cancer, away from the public health needs of the people - what will you have achieved? I dare say you would then have joined the ranks of independent Africa. The key issue will still remain not addressed: who should centres of research and learning serve and how? This is why I think the real challenge for all of us, whether south or north of the Limpopo, whether black or brown, yellow or white, is to begin thinking of how to root African universities in African soil.
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- Date Issued: 1993
Up Beat December 92/Jabuary 93
- Authors: SACHED
- Date: 1993
- Subjects: SACHED
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/116067 , vital:34294
- Description: School is out! Christmas is around the corner. So put up your feet and enjoy your well-earned holiday break. And don't be without Upbeat. This issue is packed with great holiday reading; quizzes, holiday places to visit, cassettes and books to win. Boys move over! There is a new soccer wizard, to make you tremble in your boots - HER name is Fikile Sithole. Meet her on page 8. There's also lots of great music in this issue. There's a poster of all your local favourites on page 20. But also learn about the golden oldies, who had your grandparents up and jiving. We hope you like our FREE Peace Begins with you' poster. Read it, talk about it and put it up on your wall. We hope the ideas help to bring a little peace, into your neighbourhood and home. Hundreds of readers wrote to us this year. Many letters were about violence; in the street, at home and in school. The terrible violence this year brought pain and suffering to many people. For too long apartheid has destroyed people's hopes and dreams. We want peace and democracy in our land. We want proper schools, were all young people can enjoy learning. Thank you for supporting Upbeat this year and for filling our pages with your wonderful poems, letters, stories and ideas. We wish all our readers a happy and peaceful holiday.
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- Date Issued: 1993
Up Beat Issue Number 1 1993
- Authors: SACHED
- Date: 1993
- Subjects: SACHED
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/118646 , vital:34653
- Description: Welcome to Upbeat 1993! A new school year is underway. We all hope that the coming year will bring better things; new friends, an exciting romance, success at school and an end to the violence and uncertain future in our country. We all have it in us to make change to our lives. Listen, learn and ask questions. Don't be left behind because you don't understand. That's the theme of our calendar this year. And it's FREE inside this issue of Upbeat. Our leaders have said that there will be free elections this year. But many people don't know how to vote. Don't be in the dark. Upbeat will be running stories all about voting this year. Don't miss the first article on page 14. For many people the world of computers seems too complicated. In a three part series. Upbeat will tell you all about the exciting world of computers. You could also win a fantastic IBM computer worth R3 000. Discover the world of computers on page 20. And don't miss our great new comic on page 26. Collector of Treasure is a classic African short story by Bessie Flead. It tells the story of Dikeledi, a young woman who lived in a village in Botswana. For many years this story has shocked readers. The comic captures the drama and horror of Dikeledi's remarkable courage. Don't be without Upbeat this year. We've got lots of great new stories lined up. Subscribe or get Upbeat delivered to your school. Find out how to get Upbeat quickly and easily each month, on page 6.
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- Date Issued: 1993
Up Beat Issue Number 11 1993
- Authors: SACHED
- Date: 1993
- Subjects: SACHED
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/115959 , vital:34280
- Description: Christmas is around the corner and it's holiday time again. So grab your Upbeat, put up your feet and enjoy your well- earned rest. This issue is packed with great holiday reading. Meet Mignon - the muscle maker, discover Africa's music queens or find out about a great new book to read. In our comic, The Galaxy Arcade Kids, Nomonde finds herself in trouble. Don't miss it. In this issue you will also find your FREE 1994 calendar. It is bright and colourful and its message is for peace and democracy in 1994. Upbeat believes that learning should always be fun. Find out about a great new Upbeat product on page 17. Once you see it, Africa will never be the same again! We wish all our readers a happy and peaceful holiday. During the last week of September, Upbeat together with the Weekly Mail Book Week and Film Festival, ran workshops. We went to Daveyton, Eldorado Park and Othandweni in Soweto. In the workshops students learnt how books are used to make films. Everyone was divided into groups and given a book to dramatise. With help from the Sibikwa Community Theatre Project and Soyikwa Institute for African Theatre, the groups prepared dramas which were filmed. Mrs Simelane, a teacher from one of the schools in Daveyton, said, 'I did not know that my students had such talent. This has truly been an eye- opener for me. I hope that you will run workshops next year so that more of our students can take part.' Students all agreed that the day was great fun. Everyone received a book pack at the end of the day. Now they are waiting to see the final product of their efforts once the film has been edited.
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- Date Issued: 1993
Up Beat Issue Number 3 1993
- Authors: SACHED
- Date: 1993
- Subjects: SACHED
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/115634 , vital:34209
- Description: When is the right time to have sex? Upbeat receives hundreds of letters from young people around the country, asking this question. People tell us how confused and frightened they feel. It is a very difficult question and Upbeat doesn't have the answer. Maybe your friends are 'doing it' and you feel left out. But don't rush into anything that you are not sure of. Rather wait than make a big mistake. We've an article on page 14, to make you think about whether you are ready to have sex or not. We hope it helps you make the right choice. There are lots of great stories to read in this issue. On page 4 you can find out what is happening in the troubled schools of Soweto. Read an amazing story about Argentina on page 10 about young boy who was stolen. It is a story about courage - the courage of women who stood up and demanded that the government find their children. This issue is also packed with lots of things to win. We've got FIVE great competitions that will get you thinking, drawing and making things. Don't miss the competition for an ISM computer on page 20, or the school bursaries competition on page 36. There are also competitions for music and books.
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- Date Issued: 1993
Up Beat Issue Number 5 1993
- Authors: SACHED
- Date: 1993
- Subjects: SACHED
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/115816 , vital:34240
- Description: Thousands of young people are not at school. Many more can't find jobs or are homeless with little to eat. Others are frightened and scarred by the violence that surrounds them. Apartheid has brought hardship and pain to millions of people in this country. Ongoing violence, poverty and poor schooling have left over three million young people without a decent education, jobs or opportunities to develop their talents. These young people have come to be known as 'marginalised youth.' Apartheid has left them with little hope for the future. The government doesn't care about them. Often their own families can't help them either. But they have not been forgotten. At the National Youth Development Conference youth, parents, teachers and political leaders debated and discussed ways to solve the problems of marginalised youth in our country.
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- Date Issued: 1993
Up Beat Issue Number 7 1993
- Authors: SACHED
- Date: 1993
- Subjects: SACHED
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/115849 , vital:34245
- Description: Stanley ran away from home when he was a little boy. He lived on the streets. He took drugs and ended up in jail. That was two years ago. Today he has a job as a painter. Stanley feels hopeful about the future. Kathleen was 13 when she left home to live on the streets. Today she is doing a cooking course and has moved in with her aunt in Mitchell's Plain. This issue of Upbeat is full of stories of ordinary people who have done extraordinary things. You will meet people like Kathleen and Stanley who are determined to make something of their lives. There's Gary Donnelly who is the youngest player ever to play for the NSL. He says that there is no magic in being a sportsman. It's just practice! Meet Jac Fourie from Pretoria. He was chosen to attend the International Space Camp in Alabama, USA. What an experience! If you live in Phiri in Soweto you have probably heard of Soso's Hair Salon. It is run by the amazing Sonki Nkwane. Five of his hairdressers, are friends who are still at school. All these young people have one thing in common. They are on the move! They want to challenge and change things. They want to learn and search for new opportunities, that will make a difference to their lives. Happy reading!
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- Date Issued: 1993
Wax secretion in the Cape honeybee (Apis mellifera capensis esch.) in relation to juvenile hormone and age polyethism
- Authors: Muller, Wilhelmine Josephine
- Date: 1993
- Subjects: Honeybee -- Behavior , Honeycombs
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5797 , http://hdl.handle.net/10962/d1005485
- Description: Wax secretion in worker honeybees is significantly related to the age of the worker and, while the secretion pattern remains the same, the absolute amount of wax secreted varies seasonally. Comb building festoons, previously thought to be the site of wax secretion, contain only a fraction of the newly-secreted wax in the nest. Festooning behaviour was also found to be seasonal. The amount of wax secreted by workers was significantly affected by hive. Although age-related changes in behaviour and physiology of worker honeybees appears to be modulated by juvenile hormone (JH), wax secretion is not dependent on JH. Manipulating JH III titres by injecting the hormone and manipulating the only source of the hormone (the corpora allata: CA) did not affect wax secretion. Increasing haemolymph JH titre shortly after ec1osion did not affect the amount of wax produced by workers aged 3 to 21 days, nor could a critical period be found during which elevated hormone titres would affect the rate of wax secretion. Allatectomy of newly eclosed workers did not affect wax production. Removing the putative neural feedback inhibition on the CA did not result in a change in wax production. Implanting CA from older workers into younger workers had no significant effect. Methoprene, a widely-used JH analog, caused reduced wax secretion in workers. It is suggested that methoprene poisons worker honeybees. The results obtained are consistent with an alternative model for wax secretion proposed by Butler (1954). The methodological problems found in this work are present in many other studies. When viewed in this light, the role of JH in polyethism appears dubious and there are alternative models of polyethism that do not have these shortcomings.
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- Date Issued: 1993
What can TOLs reveal about the nature of ESL reading? : a critical evaluation of current ESL research utilising think-aloud protocols
- Authors: Dixon, Robyn
- Date: 1993
- Subjects: English language -- Study and teaching -- Foreign speakers Reading comprehension Reading -- Research
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1823 , http://hdl.handle.net/10962/d1003709
- Description: This thesis explores the efficacy of think-aloud protocols (TOLs), and the extent to which the TOL technique is able to reveal the nature of ESL reading interaction with expository prose. The investigation constituted a critical evaluation of current ESL TOL research, which was essentially a theoretical examination of emerging problems derived from an in-depth assessment of current ESL TOL studies. The theoretical examination was supplemented by the practical implementation of the technique in a case study research, utilising three verbal protocols obtained from ESL students at the University of Fort Hare. The close observation afforded by the evaluative case study research paradigm provided the writer - as participant observer - with a further means of judging the merit of TOLs, which corroborated findings from the theoretical evaluation, and enabled a consideration of unanticipated issues which emerged from the practical implementation of the technique. The conclusion was that TOLs seem to have a unique ability to identify aspects of the nature of ESL reading gained from an on-line assessment of reader interaction, provided that TOL research is conducted within certain methodological and analytic research constraints. The writer has proffered suggestions for future ESL TOL research, and feels that the combination of TOL research findings with other measures of reading comprehension could elucidate aspects of ESL comprehension, making a valuable contribution to ESL reading theory and practice.
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- Date Issued: 1993
Whytie Kuluman at Richard Hatana's 60th birthday celebration
- Authors: Kuluman, Whytie
- Date: 1993
- Subjects: uncatalogued
- Type: Image
- Identifier: http://hdl.handle.net/10962/126480 , vital:35892 , RHPC-051
- Description: Whytie Kuluman at Richard Hatana's 60th birthday celebration. , Use of this resource is governed by the terms and conditions of the Creative Commons "Attribution-NonCommercial-ShareAlike" License (http://creativecommons.org/licenses/by-nc-sa/2.0/)
- Full Text: false
- Date Issued: 1993
Winter absconding as a dispersal mechanism of the Cape honeybee
- Authors: Hepburn, H Randall , Villet, Martin H , Jones, G , Carter, A , Simon, V , Coetzer, W
- Date: 1993
- Language: English
- Type: Article
- Identifier: vital:6862 , http://hdl.handle.net/10962/d1011154
- Description: The dispersal characteristics of the African honeybee, Apis mellifera scutellata, resulted in a greatly mobile hybrid front in the New World, but in Africa its hybridization zone with the Cape honeybee, Apis mellifera capensis, appears very stable.The maintenance of stable hybrid zones is predicated on a balance between dispersal and selection Knowledge on the extent of gene flow from either race is in its infancy, and the probability of successful dispersal by either race has not yet been considered. Both capensis and scutellata are notorious for absconding, capensis the more so for resource-related seasonal absconding in winter. The two races also differ fundamentally in the ways they conserve heat both behaviourally and physiologically. We investigated the energy consumption and colony survival characteristics of capensis in terms of winter absconding in a climate with cycles of warm days interspersed with cold days. These are compared with calculated values for scutellata to assess whether capensis might have a directional gene flow advantage over scutellata in their zone of hybridization.
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- Date Issued: 1993