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Identification of quantitative trait loci affecting wet carcass syndrome in sheep using high density snp genotypes
No full textEnglish: Wet carcass syndrome (WCS) is a condition predominantly found in sheep, which negatively affects the quality of their carcasses. The Northern Cape Province in South Africa and the southern part of Namibia have been identified as geographic regions with a high occurrence rate of WCS. During the pre-slaughter period, the animal appears to be clinically normal, showing no symptoms of an abnormality. However, after the removal of the skin during the slaughter process the carcass appears to be “wet”. The condition is phenotypically described as a subcutaneous accumulation of watery fluid. The areas on the carcass most affected are the brisket, flanks, hindquarters, sides, and back. The watery fluid is also found in the intramuscular connective tissue layers of both the flank and subscapular area. Unfortunately, WCS results in sheep carcasses that are deemed to be unacceptable by the end consumer from both an appearance point of view and an apparent reduced shelf life. When the description and results of previous research are considered, no physiological-, environmental- or management system was conclusively identified as a causative agent of WCS. However, stress experienced by the animals during the pre-slaughter period was identified as a possible cause and is continuously discussed throughout the current research to date. The tentative breed-specificity, i.e. Dorper sheep breed, of the condition lends some credence to a potential genetic basis for it. However, previous research has not considered a genetic variant as a causal agent of WCS. The current study employed the Ovine Infinium® HD SNP BeadChip and a genome-wide association analysis (GWAS) approach to scan the genomes of both afflicted- and unafflicted sheep in search of putative quantitative trait loci associated with the WCS phenotype. This study was not only one of the first in Southern Africa to make use of this specific BeadChip but also the first to investigate the role of genetics as a causative factor of WCS. Muscle samples from sheep carcasses (33 afflicted and 36 unafflicted) were collected from three different abattoirs in the Northern Cape Province of South Africa and Southern Namibia.
By using a candidate gene approach it was possible to map genetic loci, RYR1 and PRKAG3 (RN¯) causative of phenotypically similar conditions such as porcine stress syndrome and red, soft and exudative meat to the ovine genome. The positions of these loci (RYR1 on Chromosome 14 and PRKAG3 on Chromosome 2) mapped to the ovine genome were not in accordance with the loci showing significant association with the WCS phenotype; and no relationship was found between single nucleotide polymorphisms located within these genes and WCS. Furthermore, along with the latter approach the test of runs of homozygosity presented similar results as well as providing plausible evidence that WCS is not a recessive inherited condition. To test for an association between the phenotype (WCS) and an autosomal genetic marker(s) i.e. SNPs, a case-control study design was implemented. Given the relatively small sample size of the current study, the results obtained from the GWAS attested strong evidence of at least two loci, oar3_OARX_29903534 and oar3_OARX_113973214 positioned within the non-homologous region of the X chromosome for WCS carcasses. All afflicted animals, both males and females, carried at least one G2 allele for marker oar3_OARX_113973214, which was shown to be related to the WCS phenotype. Given the apparent influence of stress on WCS, these unafflicted males and females in all likelihood did not experience adequate levels of stress to manifest the WCS condition post-slaughter. The results of the current study also indicated that WCS may possibly be a rare X-linked inherited condition, provided only female individuals are considered. Finally, two possible major loci involving two major genes, HTR2C and DMD, positioned on the non-homologous region of the X chromosome have been identified as novel positional and functional candidate genes for WCS in sheep.Afrikaans: Natkarkassindroom (NKS) is ‘n toestand wat hoofsaaklik onder skape voorkom en wat die gehalte van hul karkasse negatief beïnvloed. Die Noord-Kaap-provinsie in Suid-Afrika asook die suidelike deel van Namibië is geïdentifiseer as geografiese gebiede met ’n hoë voorkoms van NKS. Gedurende die tydperk voor die skape geslag word, kom die dier klinies normaal voor en toon geen simptome van abnormaliteit nie. Nadat die vel egter gedurende die slagproses verwyder word, kom die karkas as “nat” voor. Die toestand word fenotipies beskryf as die onderhuidse aansameling van ‘n waterige vloeistof. Die dele van die karkas wat die meeste geaffekteer word is die borsstuk, lies, agterkwart, sye en rug. Die waterige vloeistof word ook aangetref in die binnespierse bindweefsel-lae van beide die lies- en die bladbeen-area. Ongelukkig is NKS skaapkarkasse nie aanvaarbaar vir die eindverbruiker, nie slegs omdat dit ’n onaanvaarbare voorkoms het nie, maar ook omdat dit ’n korter rakleeftyd het. Wanneer die beskrywings en resultate van vorige navorsing in ag geneem word, kon geen fisiologiese-, omgewings-, of bestuurstelsel oortuigend geïdentifiseer wat NKS veroorsaak nie. Die stres wat die diere gedurende die tydperk voor die slagproses ervaar, is egter geïdentifiseer as ’n moontlike oorsaak en word deurlopend in die navorsing tot nou toe bespreek. Die tentatiewe ras-spesifieke geneigdheid dat die toestand meer onder Dorperskape voorkom dui daarop dat daar ’n moontlike genetiese basis daarvoor is. Vorige navorsing het egter nie ’n genetiese variant as ’n veroorsakende faktor van NKS ondersoek nie. Die huidige studie het gebruik gemaak van die ‘Ovine Infinium® HD SNP’ skyfie en ’n genoomwye assossiasie-analise (GWA) om die genome van beide aangetaste- en onaangetaste skape te skandeer in die soeke na vermeende kwantitatiewe-eienskap-loki (KEL) wat geassosieer kan word met die NKS-fenotipe.
Hierdie studie is nie net slegs een van die enigste studies in Suider-Afrika om hierdie spesifieke skyfie te gebruik nie, maar ook die eerste studie wat die rol van genetika as ’n veroorsakende faktor van NKS ondersoek. Spiermonsters van 33 aangetaste- en 36 onaangetaste skaapkarkasse is versamel vanaf drie verskillende abattoirs in die Noord-Kaap-provinsie van Suid-Afrika, asook die suidelike dele van Namibië.
Deur ’n kandidaatgeenbenadering te gebruik, was dit moontlik om genetiese loki, RYR1 en PRKAG3 (RN¯), wat fenotipies-soortgelyke toestande soos varkstressindroom, en rooi, sagte en afskeidingsvleis veroorsaak, in die skaapgenoom te beskryf. Liggings van hierdie loki (RYR1 op Chromosoom 14 (OAR14) en PRKAG3 op Chromosoom 2 (OAR2)) wat op die skaapgenoom afgebeeld is, was nie in ooreenstemming met die loki wat ’n beduidende assosiasie met die NKS-fenotipe getoon het nie; en geen verhouding kon gevind word tussen enkel-nukleotied-polimorfismes (ENPs) binne hierdie gene en NKS nie. Voorts, tesame met die laasgenoemde benadering, het die genomiese soektog vir gebiede van homosigositeit (GVH) soortgelyke resultate gelewer, asook aanvaarbare bewyse dat NKS nie ’n resessiewe oorerflike toestand is nie. Om te toets vir ’n assosiasie tussen die fenotipe (NKS) en ’n outosomale genetiese merker(s), m.a.w. ENP, is daar van ’n geval-kontrolestudie gebruik gemaak. Gegewe die relatiewe klein steekproef van die huidige studie, het die resultate van die GWA-analise sterk bewyse getoon van ten minste twee loki, oar3_OARX_29903534 en oar3_OARX_113973214, in die nie-homogene area van die X-chromosoom vir NKS-karkasse. Alle aangetaste diere, beide ramme en ooie, het ten minste een G2-alleel vir merker oar3_OARX_113973214 gedra, wat duidelik ’n beduidende invloed op die NKS-fenotipe gehad het. Gegewe die oënskynlike invloed van stres op NKS, het onaangetaste ramme en ooie wat ook hierdie G2 allele dra, in alle waarskynlikheid nie genoegsame vlakke van stres ervaar om die NKS-toestand ná die slagproses te toon nie. Die resultate van die huidige studie het ook daarop gedui dat NKS moontlik ’n skaars, X-gekoppelde oorerflike toestand kan wees, gegewe slegs vroulike diere word in ag geneem. Laastens, twee moontlike KEL-areas wat twee hoofgene, HTR2C en DMD, betrek, wat geleë is op die nie-homogene area van die X-chromosoom, is geïdentifiseer as moontlike posisionele en funksionele kandidaatgene vir NKS in skape.Red Meat Research and Development SA (RMRD SA)Technology Human Resources for Industry Programme (THRIP
Identification, purification and characterisation of a keratinolytic enzyme of Chryseobacteriun carnipullorum
No full textMicrobial enzymes are essential for sustainable technology and green chemistry coupled with a wide scope of genetic manipulation. Chryseobacterium carnipullorum 9_R23581T, isolated from raw chicken is a potential keratin degrader. Feather degradation is a challenge for most conventional proteases due to the structure of keratin material which makes up more than 90% of the feathers. Keratin is composed of tightly packed α–helix and β–sheets that are further assembled into supercoiled polypeptide chains. Furthermore, the presence of hydrophobic interactions, desulphated bridges and hydrogen bonds in keratin, contribute to its recalcitrant property, resulting in an extremely stable structural protein. Keratinases have huge potential applications in various industries that include the poultry processing industry, production of rare amino acids and semi-slow nitrogen release fertilizers in organic farming among others. This study focused on identifying, purifying, and characterizing a proteolytic enzyme produced by C. carnipullorum. Growth studies were conducted to determine the stage of enzyme production, and it was observed that secretory enzymes are produced during the exponential growth phase of C. carnipullorum. The secretory proteins were visualized using SDS-PAGE and identified using LC-MS/MS. Primers were designed on selected genes of interest, which were amplified from the genome of C. carnipullorum (accession number NZ-FRCD01000002.1). Peptidase M64 was identified as the most likely main component of the keratinolytic enzymes produced by the strain used in this study. The keratinolytic enzyme (peptidase M64) was expressed in E. coli BL21[DE3] cells and purified using. Immobilized Metal Affinity Chromatography (IMAC). The molecular mass of the keratinase was determined to be about 50 kDa while its optimum temperature and pH were 50°C and 8.5, respectively. Different enzyme assays were conducted to test activity. The enzyme activity was inhibited by PMSF and it was enhanced by the presence of divalent metal ions such as MgSO4 and CaCl2.National Research Foundation (NRF)The Ministry of Health, Food and Drugs Control Laborator
PELZER, A.N. Speech
No full textCOVERAGE: 1968; 0.01 metresSpeech delivered at special National Party Congress, Paro
The role of self-esteem in the relationship between ego identity and career aspiration in adolescents
No full textEnglish: Choosing a career is a key aspect of transition for adolescents. In fact, South African
adolescents experience unique challenges with regard to their career aspirations. In the midst
of the unpredictability of careers, adolescents are expected to show increased selfdirectedness
based on a well-developed ego identity. The formation of ego identity is one of
the most important psychological tasks during adolescence. Indeed, adolescence is a critical
stage characterised by intense exploration of ego identity. In the same breath, the development
of self-esteem provides adolescents with a structure for deeper self-understanding – a crucial
factor in determining individuals’ career aspirations. The aim of this study was to explore the
relationship between ego identity and career aspiration in adolescents. Furthermore, the
possible mediating or moderating roles of self-esteem and gender in this relationship were
investigated. A non-experimental type, quantitative approach with a correlational design was
used in this study. Participants were recruited using non-probability, convenience-sampling
methods. The final sample consisted of 336 adolescents aged between 14 and 17 years, of
which 188 (56%) were females and 148 (44%) were males. The data for this study were collected using the Ego Identity Process Questionnaire (EIPQ), the Vocational Identity
Measure (VIM), and the Rosenberg Self-esteem Scale (RSES). The moderating role of gender
was investigated first before proceeding with further analyses. Gender did not play a
significant moderating role in the relationship between ego identity and career aspiration. The
relationship between the measured variables was tested using Pearson’s product moment
correlation coefficient. Statistically significant positive correlations between ego identity,
career aspiration, and self-esteem were found. A moderated hierarchical regression analysis
was completed to determine the moderating or mediating role of self-esteem in the
relationship between ego identity and career aspiration, with no statistically significant results.
According to these findings, a well-developed ego identity and a favourable self-esteem
contribute significantly to career aspiration during adolescence.French: Le choix d’une carrière est un aspect important de la transition pour les adolescents. En fait, les adolescents sud-africains rencontrent des défis uniques en ce qui concerne leurs aspirations professionnelles. Au milieu de l'imprévisibilité des carrières, les adolescents sont censés montrer une auto-orientation accrue basée sur une identité du moi bien formée. La formation de l'identité du moi est l'une des tâches psychologiques les plus importantes pendant l'adolescence. En effet, l'adolescence est une étape critique caractérisée par une exploration intense de l'identité du moi. Par ailleurs, le développement de l'estime de soi fournit aux adolescents une structure pour une meilleure compréhension de soi - un facteur crucial dans la détermination des aspirations à la carrière des individus. Le but de cette étude était d'explorer la relation entre l'identité du moi et l'aspiration à la carrière chez les adolescents. En outre, le rôle modérateur ou médiateur possibles de l'estime de soi et du genre dans cette relation a été étudié. Une approche quantitative, non expérimental avec une méthode corrélationnelle a été utilisée dans cette étude. Les participants ont été recrutés en utilisant des méthodes d'échantillonnage non probabiliste et de commodité. L'échantillon final comprenait 336 adolescents âgés de 14 à 17 ans, dont 188 (56%) étaient des femmes et 148 (44%) étaient des hommes. Les données de cette étude ont été recueillies à l'aide de questionnaire de l’identité du moi (Ego Identity Process Questionnaire ; EIPQ), de la mesure de l'identité professionnelle (Vocational Identity Measure ; VIM) et de l'échelle d'estime de soi de Rosenberg (Rosenberg Self-esteem Scale ; RSES). Le rôle modérateur du genre a été étudié en premier avant de procéder à d'autres analyses. Le genre n'a pas joué un rôle modérateur important dans la relation entre l'identité du moi et l'aspiration à la carrière. La relation entre les variables mesurées a été testée en utilisant le produit-moment de Pearson. Des corrélations positives statistiquement significatives entre l'identité du moi, l'estime de soi et l'aspiration à la carrière ont été trouvées. Une analyse de régression hiérarchique modérée a été effectuée pour déterminer le rôle modérateur ou médiateur de l'estime de soi dans la relation entre l'identité du moi et l'aspiration professionnelle, sans trouver des résultats statistiquement significatifs. Selon ces résultats, une identité du moi bien développée et une estime de soi favorable, contribuent de manière significative à l'aspiration à la carrière pendant l'adolescence
MAARTENS, J. Inventory of documents
No full textCOVERAGE: 0.10 metresTwo scrap books regarding Dr H.F. Verwoerd; Adv. B.J. Vorste
The impact of production inefficiencies on free cash flow at a producing gold mine, South Africa
No full textDissertation (MBA (Business Administration))--University of the Free State, 2018The South African mining industry is currently facing operational, political and economic challenges which threaten to render a large proportion of the operations unprofitable. Over the past few years, the gold and platinum sectors have faced the greatest challenges, and as a result have struggled to meet investor and market expectations. Although a vast number of challenges exist beyond the control of mining companies, such as fluctuating and low commodity prices, volatile exchange rates, declining ore grades, labour relations issues and policy uncertainty, it should not be forgotten that there are factors over which the operations do have control. One such factor is production output and effective mine planning. The current study focusses on one such deep-level gold mine which faces operational challenges, particularly in maintaining a stable production profile which meets monthly and annual targets. The aim of the study was to identify the main causes of production inefficiencies and operational delays and demonstrate how the production profile is impacted by these delays. The study utilised historical data which recorded the reasons for every single lost blast which had occurred over the past 5-year period spanning from 2013 – 2017. By conducting a Pareto analysis on the lost blast data, it was determined that only a small group of production delays (5 groups) accounted for the majority (~77%) of lost blasts and production delays. Furthermore, the majority of these losses and delays were as a result of human behaviour and ineffective scheduling of work to be done. The study further measured the compliance to the mine’s annual budget plan, which measured the percentage of areas planned to be mined, versus the actual area mined. The compliance investigation revealed that over the 5-year period, the monthly compliance to the budget plan, which focusses on a specific area planned to be mined, varied from 1.28% - 35.75%. These figures are relevant as they have an impact on the amount of gold mined, as well as the economic operational life of the mine. Regression analysis on the same data set revealed that a moderate negative correlation existed between the percentage compliance and the months of the year, indicating that although the compliance was low to begin with, it generally regressed as the year progressed. Analysis of past production performances revealed that the mine struggles to meet its annual production targets. However, in spite of this, the mine has always remained cash flow positive over the 5-year period analysed. That being said, on a number of occasions the mine was not able to meet their annual free cash flow targets, where in other years, the free cash flow targets were surpassed by a considerable margin. Further analysis revealed that a favourable gold price was to thank for reaching financial targets and highlighted how dependent the operation was on a gold price higher than that budgeted for. These facts are alarming, as the literature study indicated that investors are drawn to businesses which can deliver stable and profitable cash flows over an extended period of time, thus ensuring a favourable return on their investment. As it currently stands, the mine in question is one such operation which relies too heavily on outside influences (such as gold price) to meet their targets. It is recommended that the primary causes for production delays be taken seriously in an attempt to reduce such delays, which would improve the mine’s production profile, and in so doing, ensure a stable and positive cash flow for the operation
STOFFBERG, Theunis Christoffel Inventory of documents
No full textCOVERAGE 1878-1937; 27 Files; 0,55 Metres.Private papers of T.C. Stoffberg, Transvaal Senator [1928-1937]
To ascertain the role of agricultural cooperatives to sustainable agricultural development and food security in the Gauteng Province of South Africa: the case of Metsweding Municipality
No full textThis study deals with analysis of the role of agricultural cooperatives to sustainable agricultural development and food security. A simple random sampling technique was used in the selection of agricultural cooperatives. A structured questionnaire was used to obtain information on the membership and activities of the agricultural cooperative. The study has revealed that there are 12 major agricultural cooperative enterprises in the area involved in the livestock, crop, storage and processing. The agricultural produce of the agricultural cooperatives include maize, vegetables, poultry, beef, piggery, sheep & goats and animal feed and farm inputs procured are fertilizers, seeds, agro chemicals and agricultural equipment. One of the major challenges of the agricultural cooperatives in Metsweding is that of developing appropriate institutions to mobilize the members of the rural sector into a greater productive. As such small holder farmers in rural areas characterised by low resource utilization, small farm holdings, scattered, farmlands, finds it difficult to pool their resources together in order to raise their farm income and substantially improve of their living conditions. In such situation cooperatives representatives represent a strong and viable economic alternative. Cooperatives organization offers the best machinery for reaching the masses of the small scale farmers
VAN WEZEL, J. Inventory of documents
No full textCOVERAGE: 1940-1960; 0.02 metresNewspaper clippings regarding anti-war activities and the Ossewa Brandwag Movemen