The effect of feeding varying inclusion levels of velvet bean (Mucuna pruriens) seed meal on growth performance and physicochemical attributes of broiler chicken
- Authors: Mthana, Makiwa Simeon
- Date: 2020
- Subjects: Legumes Broilers (Chickens) Chickens -- Feeding and feeds
- Language: English
- Type: Thesis , Masters/Doctoral , MSc (Animal Science )
- Identifier: http://hdl.handle.net/10353/12032 , vital:39129
- Description: This study was conducted to determine the effect of feeding varying inclusion levels of velvet bean (Mucuna pruriens) seed meal (VBSM) on growth performance and physicochemical attributes of broiler chicken. Mucuna pruriens seed is an indigenous legume seed commonly found in tropical and sub-tropical areas; however, it can also be planted and cultivated. It is a viable source of dietary protein with an average concentration of 33.4%. Soybean is expensive. In addition, the South African production levels do not meet the current demand; hence the majority of soybean oilcake is imported. Recently, consumers have been conscious of the quality of chicken meat from both local and international producers. Therefore, there is a need to explore velvet bean that can grow in poorly fertilised and low rainfall areas. The study was conducted at Fort Cox Agriculture and Forestry Training Institute. One hundred and twelve (112) Cobb broilers were used, with an average weight of 45.2g. Four diets were formulated to be iso-caloric and iso-nitrogenous comprising velvet beans at 0, 10, 15 and 20 % (T1, T2, T3 and T4). The broilers were reared for 42 days with 35 days on experimental diets. Feed intake, body weight gain, feed conversion ratio, mortality, final body weight, carcass weight, and dressing percentage were determined. At day 42, twenty birds per treatment were randomly selected and fasted for five hours with water offered ad libitum. After slaughter the meat pH24, colour (L*, a*, b*), Warner-Bratzler shear force (WBSF), thawing loss (TL), and cooking loss (CL) measurements were performed on 80 breast and 80 thigh muscles. The data for growth performance and physicochemical parameters was analysed using General Linear Model (GLM) procedure of SAS (SAS, 2006), mean separation was done using LSD test option of SAS. Daily feed intake, body weight gain, final weight and carcass weight of broilers from T1 were significantly higher (P < 0.05) from other iii treatments. Daily feed intake (DFI), and body weight gain (BWG) in T1 were also higher (P < 0.05) in both phase 1 and phase 2 compared to other treatments. Feed conversion ratio (FCR) was not influenced by diets (P > 0.05). High (P < 0.05) mortality was observed on broilers fed diet with 0% VBSM compared to those fed diets comprising of VBSM. The diets did not have an effect (P > 0.05) on thigh meat pH24, lightness, redness, and WBSF. Cooking loss (25.69%) was higher (P < 0.05) in thigh meat of broilers fed the control diet. Breasts shear force (14.20) was higher in T4. Cooking loss of breast meat from broilers on T1 and T2 was higher (P < 0.05) than those from other treatments. Breast meat colour (P > 0.05) was not influenced by diets. It can be concluded that the VBSM has an effect on feed intake, growth performance and mortality of broilers, except on FCR and dressing percentage. It was also concluded that the VBSM can be included in broiler diets up to the level of 15% without negatively affecting the quality of meat.
- Full Text:
- Date Issued: 2020
Agreement and coordination in XiTsonga, SeSotho and IsiXhosa: an optimality theoretic perspective
- Authors: Mitchley, Hazel
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3423 , vital:20491
- Description: This thesis provides a unified Optimality Theoretic analysis of subject-verb agreement with coordinated preverbal subjects in three Southern Bantu languages: Xitsonga (S53), Sesotho (S33), and isiXhosa (S41). This analysis is then used to formulate a typology of agreement resolution strategies and the contexts which trigger them. Although some accounts in the Bantu literature suggest that agreement with coordinate structures is avoided by speakers (e.g. Schadeberg 1992, Voeltz 1971) especially when conjuncts are from different noun classes, I show that there is ample evidence to the contrary, and that the subject marker used is dependent on several factors, including (i) the [-HUMAN] specification on the conjuncts, (ii) whether the conjuncts are singular or plural, (iii) whether or not the conjuncts both carry the same noun class feature, and (iv) the order of the conjuncts. This thesis shows that there are various agreement resolution strategies which can beused: 1) agreement with the [+HUMAN] feature on the conjuncts, 2) agreement with the[-HUMAN] feature on the conjuncts, 3) agreement with the noun class feature on both conjuncts, 4) agreement with the noun class feature on the conjunct closest to the verb, and 5) agreement with the noun class feature on the conjunct furthest from the verb. Not all of these strategies are used by all languages, nor are these strategies interchangeable in the languages which do use them – instead, multiple factors conspire to trigger the use of a specific agreement strategy within a specific agreement featural context. I show that these effects can be captured using Optimality Theory (Prince and Smolensky 2004). The analysis makes use of seven constraints: RES#, MAX[+H], MAX[-H], DEP[-H], MAXNC, DEPNC, and AGREECLOSEST. The hierarchical ranking of these constraints not only accounts for the confinement of particular strategies to specific agreement featural contexts within a language, but also accounts for the cross-linguistic differences in the use of these strategies. I end off by examining the typological implications which follow from the OT analysis provided in this thesis.
- Full Text:
- Date Issued: 2016
An investigation into the neuroprotective effects of melatonin in a model of rotenone-induced neurodegeneration
- Authors: Kadanthode, Rubina John
- Date: 2004
- Subjects: Melatonin , Nervous system -- Degeneration -- Treatment , Rotenone
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3763 , http://hdl.handle.net/10962/d1003241 , Melatonin , Nervous system -- Degeneration -- Treatment , Rotenone
- Description: Parkinson’s disease, one of the most common neurodegenerative disorders associated with ageing, is characterised by abnormal and profound loss of nigrostriatal dopaminergic neurons. The cause of Parkinson’s disease is unknown, but epidemiological studies suggest an association with pesticides and other environmental toxins, and biochemical studies implicate oxidative damage and mitochondrial impairment, particularly at the level of complex I enzyme. Recently, rotenone, a commonly used organic pesticide and a classical inhibitor of mitochondrial complex I has been reported to reproduce the specific features of Parkinson’s disease in rodents. The mitochondrial respiratory chain is one of the most important sites of reactive oxygen species production under physiological conditions. Toxic free radicals have been implicated in a variety of neurodegenerative diseases as well as ageing itself. Melatonin, a secretory product of the pineal gland is a multifaceted free radical scavenger and natural antioxidant. In the present study, the neuroprotective effects of melatonin against the environmental neurotoxin, rotenone was investigated. Initial studies showed that inhibition of mitochondrial complex I enzyme by rotenone induced superoxide radical generation. Melatonin, administered to the rat in vivo and in vitro was able to offer neuroprotection by curtailing the production of superoxide radicals induced by rotenone. Mitochondria, being the major target of rotenone, the effects of melatonin were investigated at the mitochondrial level. Melatonin was able to increase the electron transport chain activity thus preventing the respiratory inhibition by rotenone. The pineal hormone also counteracted the action of rotenone on complex I enzyme. These results suggest melatonin’s ability to potentially limit the free radical generation and thereby modulate the mitochondrial functions. The detection and measurement of lipid peroxidation is the evidence most frequently cited to support the involvement of free radical reactions in toxicology and in human disease. Melatonin also offered significant protection in vivo and in vitro against rotenone induced lipid peroxidation. Since iron plays a major role in oxidative damage and in the progression of Parkinson’s disease, the effect of melatonin on both rotenone and iron induced lipid peroxidation was investigated, the results of which show that melatonin affords protection and this was suggested to be due to its interaction with the rotenone-iron complex that might have formed. Electrochemical studies were further used to characterise the interactions between melatonin, rotenone and iron (III). Melatonin was shown to bind with iron and thus reducing their toxicity. Histological studies were undertaken to assess the effects of melatonin on rotenone induced toxicity on the dopaminergic neurons in the rat brain. Rotenone treated brains showed extensive neuronal damage whereas with melatonin less damage was observed. Rotenone induces apoptosis via reactive oxygen species production and apoptotic cell death has been identified in PD brains. Furthermore, the apoptotic cell death was detected and quantified by the TUNEL staining. Rotenone treated sections showed signs of apoptosis whereas with melatonin, less apoptotic damage was observed. The findings of this study indicate that the neurohormone, melatonin may protect against rotenone-induced neurodegeneration. Since melatonin production falls substantially during ageing, the loss of this antioxidant is theorized to be instrumental in the degenerative processes associated with advanced age. Considering how devastating diseases such as Parkinson’s disease, are to a patient and the patient’s families, the discovery of protective agents are a matter of urgency. Further investigations using the pesticide model will help to determine the involvement of environmental exposure in the pathogenesis of human diseases as well as to test therapeutic strategies for the treatment of such diseases.
- Full Text:
- Date Issued: 2004
Rhodes University Research Report 2004
- Authors: Rhodes University
- Date: 2004
- Language: English
- Type: Text
- Identifier: vital:559 , http://hdl.handle.net/10962/d1011950
- Description: [From Introduction] Rhodes University has had another successful year in terms of research activities and outputs in what has been an exciting Centenary year and I would like to add my congratulations and thanks to those of the Vice-Chancellor to all staff and postgraduate students for their research efforts in 2004. This report documents the research highlights and outputs in its many forms during 2004. Research which is not disseminated in this manner is wasted and I would like to encourage all staff and students to continue to publish their research in the most appropriate way. I would particularly like to stress the importance of publishing research findings in subsidy earning journals and of converting conference papers into journal articles where possible. Outputs in accredited journals are one of the principle means by which the University earns research subsidy and increasing the subsidy earned in this way will directly benefit internally funded research activities. In terms of journal publications 2004 has been a very good year with the audited but still to be awarded journal units increasing to 202 units from 165 awarded in 2003. I am confident that this is a sustainable trend and it is particularly encouraging in the context of a national trend of declining research outputs. A particularly successful publication was the special edition of the SA Journal of Science which was dedicated to the Rhodes University Centenary. I would like to thank all of those staff and students who submitted articles for publication in this edition and Professor Barker for initiating and co-ordinating this publication. An aspect of research outputs which remains a serious concern is the continued poor recognition by the Department of Education of publications in the form of books, chapters, refereed conference proceedings and patents. Not only are a small fraction of these outputs accepted for subsidy purposes but to date no feedback has been given in terms of which books, chapters, etc have in fact been subsidised or why the majority of submissions are not accepted. The Department of Education has, however, indicated that such feedback will be forthcoming from 2005. A further, and possibly even more problematic, aspect of recognition of research outputs (and NRF rating) is the inability to assess outputs in the Performing and Visual Arts. Attempts have been made to address this issue at a national level but no solution appears to be likely in the near future. A concerted and unified national approach to addressing the issue of recognition of research outputs other than articles in accredited journals is urgently needed at the highest level if the research efforts in many disciplines are not to be undermined. My thanks once again to all staff and students for their continued commitment to research.
- Full Text:
- Date Issued: 2004
A critical realist account of a mentoring programme in the Faculty of Pharmacy at Rhodes University
- Authors: Oltmann, Carmen
- Date: 2009
- Subjects: Rhodes University -- Academic Development Programme Pharmacy -- Study and teaching (Higher) -- South Africa Mentoring in education -- South Africa Mentoring in Science -- South Africa Critical realism Communities of practice
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3781 , http://hdl.handle.net/10962/d1003259
- Description: This study originates from experiences I had as supervisor of the mentoring programme for first year students in the Faculty of Pharmacy, at Rhodes University. Our mentoring programme is a strategy for first year students – specifically those from previously disadvantaged backgrounds – to succeed at Rhodes University. Using an ontological meta-theory - critical realism - as my analytical lens, discourse as my unit of analysis, and Invitational Learning Theory as a theoretical tool I developed a model of mentoring based on Bhaskar’s transformational model (1993). This model illustrates the relationship between structure, culture and agency. Whilst developing this model I focussed on determining how mentors construct mentoring, and how mentoring facilitates access to a Community of Practice (CoP). Mentoring involves providing a shared space that is safe, that the mentor and mentee feel comfortable in, and that supports and challenges both the mentor and the mentee. It is a reciprocal, developmental relationship for both the mentor and the mentee that deals with issues that the mentee deems as ‘real’. Mentoring is a process, not an outcome. The mentoring strategies that the mentors employed changed as the mentors mentored. Mentors help mentees by using structures and mechanisms that worked for them, and/or by helping mentees access these structures and mechanisms. Mentoring facilitates access to a CoP by providing opportunities for engagement. This involves sharing of experiences and knowledge, and promoting discussion. The mentor helps the mentee move from being a peripheral member of the CoP to becoming a main member, i.e., becoming active, learning with and from others within the CoP. CoPs develop social capital and knowledge management. My research suggests that the knowledge, skills and attitude developed by the mentors within this study may be transferable to other aspects in Pharmacy.
- Full Text:
- Date Issued: 2009
Political grey : areas of ambiguity and contradiction
- Authors: Koekemoer, Carmen
- Date: 2014
- Subjects: Politics in art , Art -- Political aspects -- South Africa , Leadership in art , Portraits, African , Portraits, European , Art and revolutions -- South Africa
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2492 , http://hdl.handle.net/10962/d1013136
- Description: This Master of Fine Arts submission, consisting of a thesis titled ‘Political Grey: Areas of Ambiguity and Contradiction’ accompanied by an exhibition titled ‘Positions’, encompasses the concept of leadership while uncovering and expressing its ‘grey areas’ in a contemporary and undefined moment in South Africa. The concept of leadership has been complicated throughout the thesis in terms of how it is conceptualised in a traditional royal African art context as well as how Leader-Figures have been and are portrayed in both Western and African portrait genres. The notion that the new is built upon the old is continued throughout my thesis and is evident in the accompanying body of work. This notion is expressed on a number of levels: by the re-contextualisation of the print medium; the creative processes described as ‘postproduction’ which I use in my work; as well as that which is described as a ‘post-transitional’ moment. The recent political history of the country is considered, with reference made to the anti-apartheid movement and resistance art produced. Printmaking, viewed as an archetypal medium for resistance, is discussed, with reference made to its socio-political role during the 1980s as well as to the extent to which it continues to be used by contemporary artists in a different realm of conflict and change. This is demonstrated by the shift from the medium as a tool for protest to the medium as an instrument of political irony and pointed commentary.
- Full Text:
- Date Issued: 2014
The right of access to information as a means to empower citizens to participate in democratic processes : a case study of Zwelitsha, King Williams Town
- Authors: Ngcuka, Simtembile
- Date: 2018
- Subjects: Freedom of information Freedom of information -- South Africa
- Language: English
- Type: Thesis , Masters , (MPhil)Human Rights
- Identifier: http://hdl.handle.net/10353/10839 , vital:35858
- Description: The Republic of South Africa is embedded from a society that has been beleaguered. Apartheid laws were used to treat people unequally, based on race, gander, ethnic group, background, colour, belief, culture and language. These laws prohibited association of people from different races and groups. The education system was also used to instil inferiority to disadvantaged people. This system promoted a culture of secrecy and unresponsive government. The new Constitution of the Republic of South Africa was adopted in 1996. This Constitution promotes democracy and equality amongst citizens of this country. It was also adopted to bridge injustices of the past. Democracy is about allowing every citizen to participate in the processes which are meant for the development of the country. The new Constitution provided that every citizen is equal; this means every citizen must enjoy equal human Rights. This includes the Right to participate in democratic processes which are taking place. Studies show that the Right of Access to Information empowers people to participate in democratic processes. This study examines the exercise in section 32 of the Republic of South Africa Constitution (1996), by Zwelitsha community as means to empower people in participating in democratic processes taking place in their community. This Right is reinforced by Promotion of Access to Information Act No. 2 of 2000 (PAIA). The research reveals that the community of Zwelitsha is not exercising this Right which often leads to violation of other Rights. The exercise of the Right of Access to Information increases awareness and knowledge of other existing Rights, and how they can be realised and defended. The recommendations in the study underscore the need to promote the Right of Access to Information as a means to empower citizens to participate in the democratic processes in their community. This study will take the community a step closer to reaching equality. It will also educate the community of the need and importance of exercising the Right of Access to Information. It will assist the community to be able to protect other Rights. An informed community is an empowered community that can also hold the state to account.
- Full Text:
- Date Issued: 2018
Rhodes University Research Report 2003
- Authors: Rhodes University
- Date: 2003
- Language: English
- Type: Text
- Identifier: vital:558 , http://hdl.handle.net/10962/d1011947
- Description: [From Preface and Introduction] The core business of a university is teaching and research and Rhodes has excelled in both. Our success in research is also exemplified by the graduation in April of 39 PhD and 111 Masters students. Postgraduate throughput together with research outputs will play a crucial role in the new funding formula for determining Government subsidy to Institutions. In assessing the research output of universities it is important, for comparative purposes, that this is done in relation to the size of an institution. Currently this research output, per size or per capita, is calculated by dividing the research publication output by either the audited FTE’s (i.e. number of students) or the state subsidy, which is largely based on the size of the university. These calculations show that Rhodes has had the best research output per capita for the previous four years. I would like to congratulate the members of staff and postgraduates, particularly in those Departments that are consistently increasing or maintaining their research output, for their contribution to the research effort of the university. I am aware that the research contributions mentioned in this report have been made amidst many demands such as increased student numbers and a very competitive funding environment, to name a few. Asa result of positive feedback received this year we have maintained the layout and format of the first formal research report published in 2002 Please note that each Department’s/Faculty’s highlights section are as provided by the Head of Department as are the research outputs produced. The table of provisional subsidy units earned by each Department/Faculty have been included as there is often a misconception that one journal article equates to one subsidy unit. This is the case if all the authors are from Rhodes University but where articles are jointly published, a pro-rata share is calculated. Likewise due to the complex funding formula used by the Department of Education, the total research outputs produced do not equate directly to the subsidisable units. Please note that "in press" articles in 2002 but published in 2003 have already been claimed in 2002 and hence do not appear in the table but are recorded in the report. Articles that have been submitted for possible publication have not been included in the table nor the report as it is not possible to prove if the articles had been accepted for publication by the time our submission to the Department of Education was audited. Also please note that subsidy units earned for book/chapter/patent/conference proceedings publications are not included in the subsidy unit tables since we receive no feedback from the Department of Education in terms of which books/chapters/patents/proceedings are finally accepted for subsidy purposes each year. Only a small fraction of such books, chapters, patents and proceedings which are submitted actually receive subsidy. I would like to stress the need to publish in subsidy earning journals and to submit accurate information so that the University can claim as many units as possible. The total audited (but not yet awarded) publication subsidy units for journal articles which have been submitted to the Department of Education for 2003 is 180.56 units. This is some 26.08 units down on our 2002 submission and is of concern. Of this figure, publications in current non-subsidy earning journals in 2003 amounted to 5.5 units. These have been forwarded to the Department of Education for consideration for subsidy purposes. Despite the decrease in publication outputs in 2003, postgraduate student graduation, particularly PhD’s, was encouragingly high in 2003 and in general it was once again a highly successful year for research at Rhodes. I would therefore like to add my congratulations to that of the Vice-Chancellor to all staff and postgraduate students for their research efforts in 2003.
- Full Text:
- Date Issued: 2003
Rhodos, Vol. 5, No. 9
- Date: 1993-05-20
- Subjects: Rhodes University -- Rhodos , Grahamstown -- Newspapers
- Language: English
- Type: Text
- Identifier: vital:14862 , http://hdl.handle.net/10962/d1019101
- Description: The Rhodos newsletter carries news and information about events, awards, projects and developments both on and off campus. Ten editions of Rhodos are printed throughout the academic year for distribution among staff members of the University
- Full Text:
- Date Issued: 1993-05-20
Rhodes University Research Report 2001
- Authors: Rhodes University
- Date: 2001
- Language: English
- Type: Text
- Identifier: vital:556 , http://hdl.handle.net/10962/d1011936
- Description: [From Introduction] This is the first formal research report published by Rhodes University. The reason research reports have not been published previously is that the annual Council and Senate report was largely a research report and it was unnecessary to duplicate this report. However, the required format of the University’s Annual Report has changed considerably from 2001 and no longer includes detailed information on the research outputs. I would like to add my congratulations to that of the Vice-Chancellor to all the staff and postgraduate students for their research efforts in 2001. Rhodes continues to be the leading Institution in South Africa in terms of research outputs relative to its size (determined by Government subsidy income). This is very significant and it is critical that this prominence be maintained, particularly in view of the recent restructuring of Higher Education in South Africa and the greater emphasis likely to be placed on research productivity by the revised funding formula. Research at Rhodes is actively supported by the University’s Management and a variety of internal support services including, amongst others, the Library, Information Technology, laboratory and equipment support services and the entire academic, administrative and financial infrastructure. Without this support it would be impossible to conduct research. Special thanks must go to the staff in the Research Office for all their efforts in promoting research and in particular to Moira Pogrund who complied the majority of this report.
- Full Text:
- Date Issued: 2001
Species-specific plastic accumulation in the sediment and canopy of coastal vegetated habitats:
- Authors: Cozzolino, Lorenzo , Nicastro, Katy R , Zardi, Gerardo I , de los Santos, Carmen B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149410 , vital:38848 , https://doi.org/10.1016/j.scitotenv.2020.138018
- Description: Plastic waste has become ubiquitous in ecosystems worldwide. Few, recent studies report evidence of coastal vegetated habitats acting as sink for plastics, yet assessments have been completed either for macro or microplastics and focussing on just one type of vegetated habitat.
- Full Text:
- Date Issued: 2020
Petrographic and geochemical characterisation of the hangingwall and the footwall rocks (the Dipeta and R.A.T. stratigraphic units) to the Kinsevere and Nambulwa copper ore deposits of the Lufilian Arc, southern Democratic Republic of Congo
- Authors: Nkulu, Robert Kankomba
- Date: 2020
- Subjects: Petrogenesis -- Congo (Democratic Republic) , Analytical geochemistry -- Congo (Democratic Republic) , Copper ores -- Congo (Democratic Republic) , Ore deposits -- Congo (Democratic Republic) , Katangan Sequence , Geological mapping -- Congo (Democratic Republic) , Central African Copperbelt (Congo and Zambia) , Lufilian Arc , Neoproterozoic Katangan R.A.T. (Roches Argilo Talqueuse) Subgroup , Dipeta Subgroup
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/142772 , vital:38115
- Description: The Kinsevere and Nambulwa copper deposits in the Democratic Republic of Congo (D.R.C.) are set in the eastern side of the Neoproterozoic Katanga Supergroup, forming the Lufilian Arc, resulting from a cratonic collision between the Congo and the Kalahari Cratons (ca.620-570_Ma). The Katanga Supergroup was deposited in an extensional rift setting with a sedimentary thickness succession ranging between 7 to 10 km, sub-divided into: − the Roan, the Nguba and the Kundelungu Groups. The stratigraphic column of the Roan Group consists of the R.A.T. (Roche Argilo Talqueuse), the Mines, the Dipeta and the Mwashya Subgroups. Three major deformation phases have been described characterised by complex multiphase tectonics related to a curved superposition of folded, thrust and sheared blocks. The rocks of the R.A.T., Mines and Dipeta Subgroups are recognised as blocks that occur within a stratiform to discordant and diapiritic megabreccia. The blocks were rafted upward with salt tectonics, resulting in the juxtaposition with the hangingwall and the footwall terranes. Therefore, in that context it has been found that the Dipeta may appear overlying the R.A.T. Subgroup through the unconformity decollement surface of heterogeneous breccia. The petrographic observations made of the R.A.T. and Dipeta samples indicates in both units the presence of detrital quartz and feldspar that have been altered and replaced by sericite and muscovite minerals. Gypsum is intimately associated with magnesite, showing an evaporitic environment domain, while magnesite is common as alteration phase both in the R.A.T. and Dipeta Subgroups. Pyrophyllite has been observed in the Dipeta, resulting from reaction of silica with the Kaolinite at low temperature. Accessory detrital minerals include zircon, as well as xenotime intergrown with altered Fe-Ti-oxide hematite, forming complex textures with disseminated Ti-oxides both in R.A.T. and Dipeta units. Major and trace element geochemistry indicates that the Dipeta is more dolomitic and magnesite while the R.A.T. is clay-rich. The Ti2O value of Dipeta and R.A.T samples is relatively low, ranging between 0.36 and 0.69 wt.% respectively, which suggest highly evolved felsic material in the protolith. This is consistent with interpretation based on the Al2O3/TiO2 ratio, which ranges between 18 and 23 for the R.A.T. and Dipeta respectively, indicating an intermediate to felsic granitoids as the protolith of R.A.T. and Dipeta siltstones. The Ti/Zr ratio of R.A.T. and Dipeta samples of less than 10, while, the higher La/Sc ratio of between 2.6 and 5.5 (for the R.A.T. and Dipeta respectively) indicate that both the R.A.T. and Dipeta are active continental and passive margin tectonic setting. Based on the geochemical variation with depth across the R.A.T. and Dipeta and their contact zone, a geochemical fingerprinting suggests that the ratio TiO2/Al2O3 appears to be useful and could be considered as a stratigraphic geochemical maker able to discriminate the R.A.T. and the Dipeta Subgroups during the geological mapping.
- Full Text:
- Date Issued: 2020
Synthesis and characterisation of lanthanide complexes with nitrogen- and oxygen-donor ligands
- Authors: Madanhire, Tatenda
- Date: 2016
- Subjects: Rare earth metals
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/13127 , vital:27154
- Description: The reactions of Ln(NO3)3∙6H2O (Ln = Pr, Nd or Er) with the potentially tridentate O,N,O chelating ligand 2,6-pyridinedimethanol (H2pydm) were investigated, and complexes with the formula, [Ln(H2pydm)2(NO3)2](NO3) (Ln = Pr or Nd) and [Er(H2pydm)3](NO3)3 were isolated. The ten-coordinate Pr(III) and Nd(III) compounds crystallise in the triclinic space group P-1 while the nine-coordinate Er(III) complex crystallises in the monoclinic system (P21/n). The reaction of PrCl3∙6H2O with H2pydm yielded the compound, [Pr(H2pydm)3](Cl)3, that crystallises in the monoclinic system, space group P21/c with α = 90, β = 98.680(1) and γ = 90°. The nine-coordinate Pr(III) ion is bound to three H2pydm ligands, with bond distances Pr-O 2.455(2)-2.478(2) Å and Pr-N 2.6355(19)-2.64(2) Å. X-ray crystal structures of all the H2pydm complexes reveal that the ligand coordinates tridentately, via the pyridyl nitrogen atom and the two hydroxyl oxygen atoms. The electronic absorption spectra of complexes show 4f-4f transitions. Rare-earth complexes, [Ln(H2L1)2(NO3)3] [Ln = Gd, Ho or Nd], were also prepared from a Schiff base. The X-ray single-crystal diffraction studies and SHAPE analyses of the Gd(III) and Ho(III) complexes shows that the complexes are ten-coordinate and exhibit distorted tetradecahedron geometries. With proton migration occurring from the phenol group to the imine function, complexation of the lanthanides to the ligand gives the ligand a zwitterionic phenoxo-iminium form. A phenolate oxygen-bridged dinuclear complex, [Ce2(H2L1)(ovan)3(NO3)3], has been obtained by reacting Ce(NO3)3∙6H2O with an o-vanillin derived Schiff base ligand, 2-((E)-(1-hydroxy-2-methylpropan-2-ylimino)methyl)-6-methoxyphenol (H2L1). Hydrolysis of the Schiff base occurred to yield o-vanillin, which bridged two cerium atoms with the Ce∙∙∙Ce distance equal to 3.823 Å. The Ce(III) ions are both tencoordinate, but have different coordination environments, showing tetradecahedron and staggered dodecahedron geometries, respectively. The reaction of salicylaldehyde-N(4)-diethylthiosemicarbazone (H2L2) in the presence of hydrated Ln(III) nitrates led to the isolation of two novel compounds: (E)-2[(ortho-hydroxy)benzylidene]-2-(thiomethyl)-thionohydrazide (1) and bis[2,3-diaza4-(2-hydroxyphenyl)-1-thiomethyl-buta-1,3-diene]disulfide. The latter is a dimer of the former. For this asymmetric Schiff base, 1 and the symmetric disulfide, classical hydrogen bonds of the O–H∙∙∙N as well as N–H∙∙∙S (for 1) type are apparent next to C–H∙∙∙O contacts. 4-(4-Bromophenyl)-1-(propan-2-ylidene)thiosemicarbazide was also prepared upon reacting 4-(4-bromophenyl)-3-thiosemicarbazide with acetone in the presence of ethanol and La(NO3)3∙6H2O. The C=S bond length was found to be 1.6686(16) Å which is in good agreement with other thioketones whose metrical parameters have been deposited with the Cambridge Structural Database. Classical hydrogen bonds of the N–H∙∙∙N and the N–H∙∙∙Br type are observed next to C–H∙∙∙S contacts. All synthesised compounds were characterised by microanalyses, single-crystal X-ray diffraction (except for [Nd(H2L1)2(NO3)3]), 1H NMR and IR spectroscopy.
- Full Text:
- Date Issued: 2016
The effects of a 160 km run on selected anthropometric, physiological and psychological parameters
- Authors: Oltmann, Carmen
- Date: 1992
- Subjects: Marathon running -- Psychological effects , Marathon running -- Physiological effects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5148 , http://hdl.handle.net/10962/d1009706 , Marathon running -- Psychological effects , Marathon running -- Physiological effects
- Description: Twenty-one male subjects volunteered to participate in this study of the effects of an ultramarathon run under competitive conditions. Selected anthropometric measurements were made before and after the race. Blood samples were taken before, and within 10 min. of completing the race. Haematocrit and cortisol concentrations were analysed from each sample. Three ratings of perceived exertion (RPE) - local, central and overall, were obtained at two-hourly intervals throughout the race. The shortened form of the Eysenck Personality Inventory (EPI) was administered before the race. The Profile of Mood States (POMS) test was completed both before and immediately after the race. The average running intensity was estimated to be about 32% VO₂max which would not have caused major lactate accumulation. Repetitive compressive forces as a result of heel-strike resulted in intervertebral disc fluid loss. This resulted in a significant (p<0.05) decrease in stature after the race. Mobilization of glycogen, trig1ycerides and protein for metabolism as well as fluid loss via sweat resulted in significantly decreased body mass after the race. Plasma volume and serum cortisol concentrations were significantly increased after the race compared to pre-race baseline levels. Local RPE responses were dominant throughout the entire race, followed by overall RPE. Running 160 km had an effect on mood state. "Depression", "fatigue" and "confusion" (profile of Mood states) were all significantly increased compared to pre-race scores. Sleep deprivation as a result of running through the night was probably an important contributing factor. The anthropometric profile of the ultramarathon runners in this sample was more like that of the general population than elite marathon runners from the literature. The ultramarathon runners were more extroverted than elite marathon runners, but exhibited a similar Profile of Mood state before the race. The stressor - running 160 km - resulted in a 'strain response'. This was evident in the decreased stature and mass, and increased serum cortisol, "depression", "confusion" and above all "fatigue".
- Full Text:
- Date Issued: 1992
A study of a class of invariant optimal control problems on the Euclidean group SE(2)
- Authors: Adams, Ross Montague
- Date: 2011
- Subjects: Matrix groups Lie groups Extremal problems (Mathematics) Maximum principles (Mathematics) Hamilton-Jacobi equations Lyapunov stability
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5420 , http://hdl.handle.net/10962/d1006060
- Description: The aim of this thesis is to study a class of left-invariant optimal control problems on the matrix Lie group SE(2). We classify, under detached feedback equivalence, all controllable (left-invariant) control affine systems on SE(2). This result produces six types of control affine systems on SE(2). Hence, we study six associated left-invariant optimal control problems on SE(2). A left-invariant optimal control problem consists of minimizing a cost functional over the trajectory-control pairs of a left-invariant control system subject to appropriate boundary conditions. Each control problem is lifted from SE(2) to T*SE(2) ≅ SE(2) x se (2)*and then reduced to a problem on se (2)*. The maximum principle is used to obtain the optimal control and Hamiltonian corresponding to the normal extremals. Then we derive the (reduced) extremal equations on se (2)*. These equations are explicitly integrated by trigonometric and Jacobi elliptic functions. Finally, we fully classify, under Lyapunov stability, the equilibrium states of the normal extremal equations for each of the six types under consideration.
- Full Text:
- Date Issued: 2011
An investigation of parameter relationships in a high-speed digital multimedia environment
- Authors: Chigwamba, Nyasha
- Date: 2014
- Subjects: Multimedia communications , Digital communications , Local area networks (Computer networks) , Computer network architectures , Computer network protocols , Computer sound processing , Sound -- Recording and reproducing -- Digital techniques
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4725 , http://hdl.handle.net/10962/d1021153
- Description: With the rapid adoption of multimedia network technologies, a number of companies and standards bodies are introducing technologies that enhance user experience in networked multimedia environments. These technologies focus on device discovery, connection management, control, and monitoring. This study focused on control and monitoring. Multimedia networks make it possible for devices that are part of the same network to reside in different physical locations. These devices contain parameters that are used to control particular features, such as speaker volume, bass, amplifier gain, and video resolution. It is often necessary for changes in one parameter to affect other parameters, such as a synchronised change between volume and bass parameters, or collective control of multiple parameters. Thus, relationships are required between the parameters. In addition, some devices contain parameters, such as voltage, temperature, and audio level, that require constant monitoring to enable corrective action when thresholds are exceeded. Therefore, a mechanism for monitoring networked devices is required. This thesis proposes relationships that are essential for the proper functioning of a multimedia network and that should, therefore, be incorporated in standard form into a protocol, such that all devices can depend on them. Implementation mechanisms for these relationships were created. Parameter grouping and monitoring capabilities within mixing console implementations and existing control protocols were reviewed. A number of requirements for parameter grouping and monitoring were derived from this review. These requirements include a formal classification of relationship types, the ability to create relationships between parameters with different underlying value units, the ability to create relationships between parameters residing on different devices on a network, and the use of an event-driven mechanism for parameter monitoring. These requirements were the criteria used to govern the implementation mechanisms that were created as part of this study. Parameter grouping and monitoring mechanisms were implemented for the XFN protocol. The mechanisms implemented fulfil the requirements derived from the review of capabilities of mixing consoles and existing control protocols. The formal classification of relationship types was implemented within XFN parameters using lists that keep track of the relationships between each XFN parameter and other XFN parameters that reside on the same device or on other devices on the network. A common value unit, known as the global unit, was defined for use as the value format within value update messages between XFN parameters that have relationships. Mapping tables were used to translate the global unit values to application-specific (universal) units, such as decibels (dB). A mechanism for bulk parameter retrieval within the XFN protocol was augmented to produce an event-driven mechanism for parameter monitoring. These implementation mechanisms were applied to an XFN-protocol-compliant graphical control application to demonstrate their usage within an end user context. At the time of this study, the XFN protocol was undergoing standardisation within the Audio Engineering Society. The AES-64 standard has now been approved. Most of the implementation mechanisms resulting from this study have been incorporated into this standard.
- Full Text:
- Date Issued: 2014
Effect of Mucuna pruriens based-diets on fatty acids composition and sensory attributes of meat from broiler chickens
- Authors: Makhamba, Nasiphi
- Date: 2020-11
- Subjects: Fatty acids , Broilers (Chickens)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20771 , vital:46554
- Description: The current study was conducted to determine the effect of feeding different inclusion levels of processed Mucuna pruriens on fatty acid composition and sensory attributes of broiler chickens. 120 Cob500 broilers were used in the experiment. The experiment was divided into 4 treatment (0, 10, 15 and 20 percent of Mucuna pruriens) groups, each treatment with 6 replicates (5 birds per replicate) in a completely randomized design. The first treatment (0 percent) was used as control against the three different levels of Mucuna pruriens. The birds were reared in a deep litter system until they reached slaughter weight of 2kg. At day 42 a total of 80 birds were slaughtered and breast muscles were sampled for the evaluation of sensory attributes and fatty acid composition. For sensory evaluation meat samples were prepared and boiled at 80°C until the internal temperature reached 82°C, 40 consumers were used to assess the meat samples and give scores according to 9-point hedonic scale. The fatty acid content was determined and recorded using the gas chromatography. Total saturated fatty acid (SFA), total monounsaturated fatty acid (MUFA), and total polyunsaturated fatty acid (PUFA) of the breast meat were not affected by diets. Omega-6 and omega-3 fatty acid were also not influenced by treatment diets. However, breast muscle from broilers fed 20 percent Mucuna pruriens seed meal inclusion had lower Myristic acid. The sensory attributes; aroma, colour, flavour, juiciness, tenderness and acceptability were assessed, dietary treatments affected the juiciness, tenderness and acceptability of meat, the treatments showed no significant difference on colour, aroma and flavour. Different age groups accepted the meat differently, the respondents that were between 18 and 22 years old gave the highest scores to the acceptability of meat than the other age groups, and different age groups also gave different scores in the aroma of meat. Females and males accepted the meat differently, the female respondents gave higher scores on the flavour of meat than males. Different inclusion levels of Mucuna pruriens positively affected fatty acid composition and sensory attributes of broiler chickens without causing any detrimental effects. , Thesis (MSc) (Animal Science) -- University of Fort Hare, 2021
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- Date Issued: 2020-11
An assessment of the performance appraisal system utilised for junior and middle level management within the South African National Defence Force
- Authors: Terblanche, Graham Martin
- Date: 2004
- Subjects: Middle managers -- Rating of -- South Africa , South Africa. National Defence Force Officials and employees Rating of
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10884 , http://hdl.handle.net/10948/148 , Middle managers -- Rating of -- South Africa , South Africa. National Defence Force Officials and employees Rating of
- Description: The research problem of this study was to assess the extent to which the appraisal system for junior and middle level managers in the South African National Defence Force (SANDF) met the requirements and guidelines for performance appraisal as stipulated in the literature. To achieve this objective, the following procedure was followed: · A survey of existing literature, related to performance appraisal, was conducted. The literature study focused on the requirements for an effective performance appraisal system, appraisal methods and appraisal errors. Attention was also focused on who should take responsibility for performance appraisal and the importance of regularly evaluating the performance appraisal system to meet the demands of a changing environment. The second part of the literature study dealt with the guidelines for establishing an effective appraisal system as well as performance management processes and cycles that are critical for the effectiveness of an appraisal system. The theoretical study formed the basis for the development of a survey questionnaire to establish the extent to which junior and middle level managers in the SANDF agreed with the theoretical guidelines. The survey was administered to a randomly selected group of junior and middle level managers who were representative of the South African Army, Airforce and Medical Services. The empirical results indicated that there was concurrence with many of the guidelines in the literature, but that there were areas that could be improved. It became evident that many respondents felt that the current system was not entirely fair and was not adapted to meet the needs of the integrated SANDF. Specifically, results indicated that the system should be re-evaluated to eliminate bias and to enhance the development of clear standards, both on a quantitative and qualitative level. It became clear that training and communication were important to the successful development and utilisation of a performance appraisal system. An effective performance appraisal system that is integrated with the overall performance management system of an organisation will enhance productivity, satisfaction and the attainment of goals.
- Full Text:
- Date Issued: 2004
Fungal remediation of winery and distillery wastewaters using Trametes pubescens MB 89 and the enhanced production of a high-value enzyme therein
- Authors: Strong, Peter James
- Date: 2008
- Subjects: Fungal remediation Distilleries -- Waste disposal Wine and wine making -- Waste disposal Bioremediation Laccase Enzymes -- Biotechnology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3932 , http://hdl.handle.net/10962/d1003991
- Description: In this study white-rot fungi were investigated for their efficiency at distillery wastewater remediation and the production of laccase as a valuable by-product. Distillery wastewaters are high in organic load and low in pH. The presence of phenolic compounds can lead to extremely colour-rich wastewaters and can be toxic to microorganisms. The presence of the inorganic ions may also affect biological treatment. White-rot fungi are unique among eukaryotic or prokaryotic microbes in possessing powerful oxidative enzyme systems that can degrade lignin to carbon dioxide. These ligninolytic enzymes, such as lignin peroxidase, manganese peroxidase and laccase, are capable of degrading a vast range of toxic, recalcitrant environmental pollutants and this makes the white-rot fungi strong candidates for the bioremediation of polluted soils and waters. The laccase enzyme alone has shown remediation potential in wastewaters such as beer production effluent, olive mill wastewater, alcohol distillery wastes, dye-containing wastewaters from the textile industry as well as wastewaters from the paper and pulp industry. It has been shown to be capable of remediating soils and waters polluted with chlorinated phenolic compounds, polyaromatic hydrocarbons, nitrosubstituted compounds and fungicides, herbicides and insecticides.
- Full Text:
- Date Issued: 2008
Reactivity of Rhenium (iii) and Rhenium (V) with multidentate NN-and no-donor ligands
- Authors: Yumata, Nonzaliseko Christine
- Date: 2010
- Subjects: Rhenium , Ligands
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10373 , http://hdl.handle.net/10948/1085 , Rhenium , Ligands
- Description: The reaction of the potentially tridentate Schiff-base chelate Hhaep [Haep = N’-(1- (2-hydroxyphenyl)ethylidene)benzohydrazide] with [ReCl3(benzil)(PPh3)] and trans-[ReOCl3(PPh3)2] produced the neutral oxorhenium(V) complexes cis- [ReOCl2(mep)] [Hmep = 2-(1-iminoethyl)phenol] and cis-[ReOCI2(meb)(PPh3)] [Hmeb = N’-(propan-2-ylidene)benzohydrazide] in ethanol and acetone respectively. In both reactions the Hhaep molecule cleaves to give different coordinated bidentate NO-donor chelates coordinated to the rhenium(V) centers. The X-ray studies reveal that mep is present as a bidentate, monoanionic Schiffbase coordinating through the neutral imino nitrogen and the deprotonated phenolate oxygen in cis-[ReOCl2(mep)]. The bond distances and angles in cis- [ReOCI2(meb)(PPh3)] confirm that meb coordinates to the metal in the enolate form. The distorted octahedral complex fac-[ReCl3(dpa)(PPh3)] was prepared by the reaction of trans-[ReCl3(MeCN)(PPh3)2] with a twofold molar excess of dpa in acetonitrile under a nitrogen atmosphere. The compound dpa.HCl.2H2O was obtained as a by-product in the reaction of dpa with trans-[ReCI3(MeCN)(PPh3)2] in acetonitrile. The reaction of trans-[ReCl3(MeCN)(PPh3)2] with a twofold molar excess of 6- amino-3-methyl-1-phenyl-4-azahept-2-ene-1-one (Hamp) in acetonitrile led to the isolation of cis-[ReCl2(bat)(PPh3)2]. On complexation to the metal center Hamp decomposed to give the coordinated benzoylacetone (bat). Bat is present as a monoanionic bidentate chelate. The complexes [ReVOCI(had)] and [ReIVCl(had)(PPh3)](ReO4) were prepared from the reaction of trans-[ReCl3(MeCN)(PPh3)2] with N,N-bis((2-hydroxybenzyl)-2- aminoethyl)dimethylamine (H2had) in ethanol under various reaction conditions. The treatment of [ReCl3(benzil)(PPh3)] with 2-[((2- pyridinylmethyl)amino)methyl]phenol (Hham) in a 2:1 molar ratio in acetonitrile led to the isolation of the hydrogen-bonded dimer [ReOCl2(ham)]2. The distorted octahedral complex [ReOCl(hap)] [H2hap = N,N-bis(2- hydroxybenzyl)aminomethylpyridine] was prepared from the reaction of trans- [ReCl3(MeCN)(PPh3)2] with a twofold molar excess of H2hap in acetonitrile. The X-ray crystal structure analysis shows that the chloride is coordinated trans to the tripodal tertiary amino nitrogen, with a phenolate oxygen trans to the oxo oxygen.
- Full Text:
- Date Issued: 2010