Management of Fusarium wilt of banana, one of the most important diseases of agricultural crops, is complicated and involves the consideration of factors such as the biology, epidemiology and population structure of the pathogen, and genetic resources and production practices of the crop. The development of an integrated disease management programme, therefore, is of great importance in countries where the Fusarium wilt pathogen, Fusarium oxysporum f.sp. cubense Foc, has been introduced into banaria fields, and where resistant cultivars are not acceptable to local markets. To achieve this, it is important to investigate new management strategies and to review methods that have been less successful in the past. These management practices need to be practical and affordable. Since certain cultural practices have proven to be effective, management practices that could compliment them should be considered. This thesis has attempted to investigate such practices in order to develop an integrated disease management programme for Fusarium wilt of banana. One of the most important findings of this study, was that the surface sterilant previously used to prevent the introduction of the Fusarium wilt into uninfected areas in South Africa, are not effective. The sterilants Sporekill and Prazin proved to be highly effective, and are now recommended to replace the sterilants previously used. Several fungicides reduced mycelial growth of Foc in vitro, with the OMI fungicides and Benomyl found to be the most effective. The same fungicides reduced the disease severity of Fusarium wilt in the greenhouse significantly, especially when they were applied as root dip treatments. None of the fungicides found effective against Foc have been evaluated in the field against Foc before. The next step, therefore, would be to evaluate root dip treatments combined with drench treatment in the field. Although it is expected that these fungicides might have a negative effect on the microbial populations in the soil, this has yet to be investigated. Fungicides may even weaken or stress the pathogen, making it more vulnerable for the action of an effective biocontrol agent or agents. Chemical activators are probably one of the most attractive strategies to combat Fusarium wilt of banana, since it stimulate the plants' own defence system. Banana plantlets were found to be quite sensitive to the amount and method whereby chemical activators were applied. The activator benzo-(1,2,3)thiadiazole-7-carbothioic acid S-methyl ester induced resistance against Foc on the susceptible Williams cultivar in the greenhouse, but not in the field. In field studies, environmental conditions were much more variable than in the greenhouse, which made it difficult to evaluate the effectiveness of chemical activators. Sodium nitroprusside and a product containing the harpin protein showed promising results on the Williams and DRSI cultivars, respectively. These activators need to be considered as part of an integrated disease management programme. Since they are not directly applied to the soil, they will not have a negative effect on the microbial populations in the soil. Several Fusarium isolates had been collected from banana fields with disease suppressive soils in Kiepersol, South Africa. Most of these isolates were F. oxysporum, and with the exception of one isolate, proved to be non-pathogenic to banana plants. A PCR-based restriction fragment length polymorphism (RFLP) analysis of the intergenic spacer region of the ribosomal RNA operon grouped the non-pathogenic F. oxysporum isolates into 12 distinct genotypes. A great diversity could be seen among the non-pathogenic isolates compared to the pathogenic Foc isolates. The known-biological control agent F047 grouped with three of the South African isolates, while the one pathogenic isolate grouped with the pathogenic Foc from diseased Cavendish bananas in South Africa By using PCR-RFLPs, we were able to rapidly characterize the structure of non-pathogenic isolates of F. oxysporum in disease suppressive soils in Kiepersol. This could assist us in our search for potential biological control agents for Fusarium wilt of banana. Representative isolates from the 12 genotype groups were selected for evaluation of Fusarium wilt suppressive properties in banana. These non-pathogenic F. oxysporum isolates appeared to be good biological control candidates and was compared to known biological control agents and commercial biological control products. Fourteen of the non-pathogenic isolates, the combination of two Trichoderma strains form suppressive soils in South Africa, and two Pseudomonas fluorescens isolates were found to significantly reduce Fusarium wilt development in the greenhouse. The commercial products Patostop, B-rus and a mixture of arbuscular mycorrhizae were also found to suppress the disease severity of Foc significantly. The well-know biological control agent F047 proved to be not effective. Results concluded that two of the non-pathogenic F. oxysporum isolates and the two P. fluorescens isolates, one of which was the well-known WCS 417, were the most effective of all the agents evaluated. Since combinations of biocontrol agents may provide even more consistent and effective control than a single agent, future research will include the combination of biocontrol agents found effective in this study. It would also be of great value to determine the mode of action of these isolates, so that isolates with different modes of action could be combined to enhance the suppression effect. Biological control can be a very useful component of an integrated disease management programme, since the effective agent or agents can easily be established on tissue culture banana plantlets before they are planted in the field. AFRIKAANS : Een van seker die mees belangrikste grondgedraagte siektes in lanbou, is Fusarium verwelksiekt van piesangs. In Suid-Afrika, is die siekte verantwoordelik vir emstige verliese in die piesang produksie. Aangesien daar geen weerstandbiedende kultivars beskikbaar is wat deur die mark aanvaar word nie, is dit van kardinale belang dat 'n geintegreerde siekte beheer program vir Suid-Afrika ontwikkel word. Voordat so 'n program saamgestel kan word, is dit belangrik dat verskeie faktore aangaande die patogeen en piesang poduksiepraktyke in ag geneem moet word. Beheermaatreëls moet prakties en bekostigbaar wees, en moet die reeds bestaande praktyke kan bevoordeel. Studies wat in hierdie tesis aangebied word, oorweeg beheermaatreëls wat gekombineer kan word met die huidige praktyke, nadat vorige praktyke ook in ag geneem is. Daar word gesoek na nuwe meer doeltreffende en ekonomiese metodes om siektes te beheer. Metodes wat doeltreffend aangewend kan word om die voorkoms van die siekte te vermirider. In vitro en in vivo studies het getoon dat die DMI swamdoders en Benomil die groei van die patogeen en die ontwikkeling van Fusarium verwelksiekte die meeste onderdruk. Die beste resultate is in die glashuis gevind nadat die wortels van plante in die middels geweek is. Positiewe resultate is ook verkry met die grondtoediening van Benomil 'n week nadat plante geplant is in Foc geïnfekteerde grond. Die chemiese beheer van Fusarium verwelsiekte kan verder ondersoek word deur die effek van die grondtoedienings en wortelbehandelings in die veld te ondersoek. Daar word egter verwag dat die swamdoders moontlik 'n negatiewe uitwerking op die mikrobiese aktiwiteit in die grond kan veroorsaak. Die gebruik van effektiewe ontsmettingmiddels is uiters belangrik vir die voorkomende beheer van Fusarium verwelkdiekte op piesangs. Die ontsmettingmiddel, koper oxichloried, wat tot onlangs in Suid Afrika gebruik was, is ondoeltreffend gevind vir ontsmettingsdoeleindes. Prazin en Sporekill, twee omgewingsvriendelike middels, is baie effektief gevind en word dus aanbeveel vir die ontsetting van voertuie, skoene en veld toerusing. Chemiese plant aktiveerders stimuleer plante om hulleself te beskerm deur middel van weerstandsmeganisms. Piesang plante het sensitiwiteit getoon toonoor die konsentrasie en die toedieningsmetode van hierdie chemiese aktiveerders. In die glashuisproewe het die aktiveerder benzo-(1,2,3)thiadiazole-7-carbothioic suur S-metiel ester weerstand gestimuleer in die Williams kultivar. As gevolg van veranderende toestande in die veld was dit moeiliker om die chemiese aktiveerders se werking te evalueer. Nogtans het die middels natrium nitroprussied en 'n produk wat die protein harpin bevat die voorkoms van siekte op die Williams en DRS 1 plante verlaag. Chemiese aktiveerders behoort sterk oorweeg te word as deel van 'n geintegreerde beheer program, aangesien chemiese aktiveerders nie direk tot die grond aangewend word nie, en geen negatiewe uitwerking op die natuurlike mikrobiese populasies in die grond uitoefen nie. Verskeie Fusarium isolate is geisoleer vanuit siekte onderdukkende gronde in die Kiepersol area van Suid-Afrika. Die meeste van die isolate is geidentifiseer as F. oxsysporum. 'n PKR-gebaseerde restriksie fragment lengte polimorfisme (RFLP) ontleding van die "intergenic spacer region" van die ribosomale DNS operon het die niepatogeniese F. oxysporum isolate in 12 verskillende genotypes opgedeel. 'n Groot diversiteit was sigbaar onder die nie-patogeniese isolate in vergelyking met die patogeniese foc isolate. Die bekende beheer agent, Fo47 het gegroepeer saam met drie van die Suid Afrikaanse nie-patogene. Hierdie tegniek het ons in staat gestel om die nie-patogeniese populasie van onderdrukkende gronde in Kiepersol vinnig te karakteriseer en potentiele biologiese agente te identifiseer. Verteenwoordigende isolate van die 12 genotipiese groepe wat geidnetifiseer is, is geselekteer vir verdere evaluasie. Dit is gevind dat die isolate goeie kandidate vir moontlike bio-beheer agente maak. Die onderdrukkingsvermoe van die nie-patogene is vergelyk met die van bekende bio-beheer agente en komersiele produkte wat beskikbaar is. Veertien van die nie-patogene, die kombinasie van twee Trichoderma spp., en twee Pseudomonas fluorescens isolate het die siekte ontwikkeling van Fusarium verwelking merkwaardig onderdruk in die glashuis. Die komersiele produkte Patostop®, B-rus en die kombinasie van twee mycorrhizae isolate is ook gevind om die voorkoms van siekte te verlaag. Die wel-bekende biobeheer agent Fo47 is oneffektief gevind teen Fusarium verwelksiekte van piesangs. Resultate van die studie het bewys dat twee van die nie-patogeniese F.Oxysporum isolate en twee P. Fluorescens isolate, waarvan een die welbekende WCS 417 is, uiters effektiewe beheer agente teen Foc is. Toekomstige studies sal fokus op die kombinasie van die bio-beheer agente wat die meeste potensiaal getoon het in die studie, asook hulle meganismes van werking. Biologiese beheer is van groot waarde vir 'n geïntegreerde beheer program. Dit kan maklik met bestaande beheer maatreëls gekombineer word en potensiële biologiese beheer agente kan vooraf op weefselkultuur plante in die kwekery gevestig word. / Dissertation (MSc)--University of Pretoria, 2011. / Microbiology and Plant Pathology / unrestricted

The iron ore mining industry makes use of various processes that result in the release of airborne dust into the surrounding atmosphere where workers are exposed, to produce a final product. The deposition in the lung and toxicological influences of airborne dust can be determined by their physical- and chemical characteristics. The Occupational Health and Safety Act (OHSA) regulations for hazardous chemical substances have no current system of how the physical- and chemical properties of particulates originating from specific areas will influence a worker‘s exposure and health, especially for ultrafine particles (UFP). It is therefore imperative to characterise airborne dust containing micrometer and UFP size particles originating from specific areas to determine if there are physical- and chemical characteristics that may or may not have an influence on the workers‘ health. Aim: This pilot study is aimed at the physical- and chemical characterisation of the airborne iron ore dust generated at the process areas of an opencast iron ore mine. Method: Sampled areas included the Primary-secondary crusher, Tertiary crusher, Quaternary crusher and Sifting house. Gravimetric sampling was conducted through the use of static inhalable- and respirable samplers in conjunction with optical- and condensation particle counters that were placed near airborne dust- emitting sources. Physical- and chemical characterisation was done with the use of scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Results: The results found in the study indicate high mass concentration levels of inhalable dust at all four process areas, as well as high levels of respirable dust found at the primary- secondary crusher area. Particle size distribution optical particle counter (OPC) results indicate that the majority of particles at all four process areas are in the region of 0.3 μm in size. Condensation particle counter (CPC) results integrated with OPC results indicate that at the primarysecondary and Tertiary crushers the majority of particles are found to be in the size fraction <0.3 μm. SEM analysis indicates that particle agglomeration largely occurs in the airborne iron ore dust. Particle splinters originating from larger particle collisions and breakages are present in the airborne dust. EDS analysis indicates that the elemental majority of the airborne iron ore dust consists of iron, oxygen, carbon, aluminium, silicon, potassium and calcium. The elemental percentages differ from each process area where an increase in iron and decrease in impurities can be seen as the ore moves through the beneficiation process from the Primary-secondary crusher to the Sifting house. Conclusion: The results obtained from the physical- and chemical properties of the airborne iron ore dust indicate high risk of over-exposure to the respiratory system, as well as possible ultrafine particle systemic exposure, that may overwhelm the physiological defense mechanisms of the human body and lead to reactive oxygen species (ROS) formation and the development of pathologies such as siderosis, silicasiderosis and lung cancer. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2014

A pharmaceutical dosage form is an entity that is administered to patients so that they receive an effective dose of an active pharmaceutical ingredient (API). The proper design and formulation of a transdermal dosage form require a thorough understanding of the physiological factors affecting percutaneous penetration and physicochemical characteristics of the API, as well as that of the pharmaceutical exipients that are used during formulation. The API and pharmaceutical excipients must be compatible with one another to produce a formulation that is stable, efficacious, attractive, easy to administer, and safe (Mahato, 2007:11). Amongst others, the physicochemical properties indicate the suitability of the type of dosage form, as well as any potential problems associated with instability, poor permeation and the target site to be reached (Wells & Aulton, 2002:337). Therefore, when developing new or improved dosage forms, it is of utmost importance to evaluate the factors influencing design and formulation to provide the best possible dosage form and formulation for the API in question. Delivery of an API through the skin has long been a promising concept due to its large surface area, ease of access, vast exposure to the circulatory and lymphatic networks, and non-invasive nature of the therapy. This is true whether a local or systemic pharmacological effect is desired (Aukunuru et al., 2007:856). However, most APIs are administered orally as this route is considered to be the simplest, most convenient and safest route of API administration. Since ibuprofen is highly metabolised in the liver and gastrointestinal tract, oral administration thereof results in decreased bioavailability. Furthermore, it also causes gastric mucosal damage, bleeding and ulceration. Another obstacle associated with oral API delivery is that some APIs require continuous delivery which is difficult to achieve (Bouwstra et al., 2003:3). Therefore, there is significant interest to develop topical dosage forms for ibuprofen to avoid side effects associated with oral delivery and to provide relatively consistent API levels at the application site for prolonged periods (Rhee et al., 2003:14). The aim of this study was to determine the influence of selected formulation factors on the transdermal delivery of ibuprofen. In order to achieve this aim, the physicochemical properties of ibuprofen had to be evaluated. The aqueous solubility, pH-solubility profile, octanol-water partition coefficient (log P-value) and octanol-buffer distribution coefficient (log D-values, pH 5 and 7.4) of ibuprofen were determined. According to Naik et al., (2000:319) the ideal aqueous solubility of APIs for transdermal delivery should be more than 1 mg.ml-1. However, results showed that ibuprofen depicted an aqueous solubility of 0.096 mg.ml-1 ± 25.483, which indicated poor water solubility and would therefore be rendered less favourable for transdermal delivery if only considering the aqueous solubility. The pH-solubility profile depicted that ibuprofen was less soluble at low pH-values and more soluble at higher pH-values. Previous research indicated that the ideal log Pvalues for transdermal API permeation of non steroid anti-inflammatory drugs (NSAIDs) are between 2 and 3 (Swart et al., 2005:72). Results obtained during this study indicated a log P-value of 4.238 for ibuprofen. This value was not included in the ideal range, which is an indication that the lipophilic/hydrophilic properties are not ideal, and this might therefore; contribute to poor ibuprofen penetration through the skin. Furthermore, the obtained log D-values at pH 5 and 7.4 were 3.105 and 0.386, respectively. Therefore, it would be expected that ibuprofen incorporated into a formulation prepared at a pH of 5 would more readily permeate the skin compared to ibuprofen incorporated into a formulation prepared at a pH of 7.4. A gel, an emulgel and a Pheroid™ emulgel were formulated at pH 5 and 7.4, in order to examine which dosage form formulated at which pH would deliver enhanced transdermal delivery. Obtained diffusion results of the different semi-solid formulations were furthermore compared to a South African marketed commercial product (Nurofen® gel) in order to establish if a comparable formulation could be obtained. An artificial membrane was used to conduct the membrane permeation studies over a period of 6 h, in order to determine whether ibuprofen was in fact released from the formulations through the membrane. Skin permeation studies were conducted using Franz diffusion cells over a period of 12 h where samples were withdrawn at specified time intervals. All the formulations exhibited an increase in the average cumulative amount of ibuprofen released from the formulations and that permeated the membrane when compared to Nurofen® gel. This increase was statistically significant (p<0.05) for the gel, emulgel and Pheroid™ emulgel at pH 7.4. The gel at pH 7.4 exhibited the highest cumulative amount of ibuprofen that permeated the membrane. Preparations formulated at a pH of 5, did not differ significantly from Nurofen® when the average cumulative amount of ibuprofen that permeated the membrane were compared. The following rank order for the average cumulative amount released from the formulations could be established: Gel (pH 7.4) >>>> Pheroid™ emulgel (pH 7.4) > Emulgel (pH 7.4) >>> Gel (pH 5)> Pheroid™ emulgel (pH 5) ≈ Emulgel (pH 5) > Nurofen® gel. On the other hand, all the formulations exhibited an increase in the average cumulative amount of ibuprofen that permeated the skin when compared to Nurofen® gel. This increase was statistically significant (p < 0.05) for the gel, emulgel and Pheroid™ emulgel at pH 5, as well as the emulgel and Pheroid™ emulgel at pH 7.4. The emulgel at pH 5 exhibited the highest cumulative amount of ibuprofen that permeated the skin. The following rank order for the average cumulative amount released from the formulations and that permeated the skin could be established: Emulgel (pH 5) >> Pheroid™ emulgel (pH 5) > Gel (pH 5) > Emulgel (pH 7.4)> Pheroid™ emulgel (pH 7.4) ≈ Emulgel (pH 7.4) >> Nurofen® gel > Gel (pH 7.4). From this rank order it was clear that a trend was followed where the pH of formulation also played a role in ibuprofen permeation. All the formulations exhibited a higher release rate and flux when compared to Nurofen® gel. This was statistically significant for the emulgel, gel and Pheroid™ emulgel at pH 7.4. The gel at pH 7.4 exhibited the highest release rate and flux. This was observed for the membrane and skin permeation studies. All the formulations (including Nurofen® gel) presented a correlation coefficient (r2) of 0.972 – 0.995 for membrane permeation studies, and 0.950 – 0.978 for skin permeation studies; indicating that the release of ibuprofen from each of the formulations could be described by the Higuchi model. Furthermore, all the formulations exhibited a prolonged lag time compared to Nurofen® gel which indicated that the ibuprofen was retained for a longer time by the base. This was statistically significant (p < 0.05) for the emulgel at pH 7.4, the gel and Pheroid™ emulgel at pH 5. The gel at pH 7.4 exhibited a lag time closest to that of Nurofen® gel and this difference could not be classified as statistically significant (p > 0.286). This was observed for the membrane and skin permeation studies. Nurofen® gel exhibited the highest ibuprofen concentration in the stratum corneum as well as in the epidermis followed by the gel at pH 7.4. However, results obtained for all the formulations indicated that topical as well as transdermal delivery of ibuprofen was achieved. The pH of a formulation plays an important role with respect to API permeation. Ibuprofen is reported to have a pKa value 4.4 (Dollery, 1999:I1); and by application of the Henderson-Hasselbach equation, at pH 5, 20.08% of ibuprofen will be present in its unionised form and at pH 7.4, 0.1% ibuprofen will exist in its unionised form. Since the unionised form of APIs is more lipid soluble than the ionised form, unionised forms of APIs permeate more readily across the lipid membranes (Surber & Smith, 2000:27). Therefore, it would be expected that ibuprofen formulated at pH 5 would be more permeable than formulations at pH 7.4. However, this did not correspond to the results (membrane studies) obtained in this study. It may be attributed to the solubility of ibuprofen in the different formulations. According to the pH-solubility profile of ibuprofen obtained in this study, it was more soluble at pH 7.4 than at pH 5. This was due to the fact that ibuprofen is a weak acidic compound, and for every 3 units away from the pKa-value, the solubility changes 10-fold (Mahato, 2007:14). However, with regard to the skin permeation studies, enhanced permeation was obtained with the formulations prepared at pH 5. This was in accordance with Corrigan et al., (2003:148) who stated that NSAIDs are less soluble and more permeable at low pH values, and more soluble and less permeable at high pH values. This was most probably due to the fact that unionised species, although possessing a lower aqueous solubility than the ionised species, resulted in enhanced skin permeation due to being more lipid-soluble. Finally, stability tests on the different semi-solid formulations for a period of three months at different temperature and humidity conditions were conducted to determine product stability. The formulations were stored at 25 °C/60% RH (relative humidity), 30 °C/60% RH and 40 °C/75% RH. Stability tests included: mass variation, pH, zeta potential, droplet size, visual appearance, assay, and viscosity. No significant change was observed for mass variation, pH, zeta potential and droplet size over the three months for any of the different formulations stored at the different storage conditions. In addition, no significant change in colour was observed for the gel and emulgel formulations at pH 5 and 7.4 over the three months at all the storage conditions. However, it was observed that the formulations containing Pheroid™ showed a drastic change in colour at all the storage conditions. This might have been due to oxidation of certain components present in the Pheroid™ system. Consequently, further investigation is necessary to find the cause of the discolouration and a method to prevent it. The gel formulated at pH 5 depicted the formation of crystals. This might have been due to the fact that the solubility of ibuprofen was exceeded, leading to it precipitating from the formulation. A possible contributing factor to the varying assay values obtained during the study might have been due to non-homogenous sample withdrawal. On the other hand, no significant change was observed for the emulgel and Pheroid™ emulgel formulated at pH 5 and 7.4. The emulgel and Pheroid™ emulgel formulated at pH 5 depicted relative instability (according to the International Conference on Harmonisation of Technical Requirements For Registration of Pharmaceuticals for Human Use, ICH) only at 40 °C/75% RH with a change in ibuprofen content of more than 5% (6.78 and 6.46%, respectively). The gel, emulgel and Pheroid™ emulgel at pH 7.4 exhibited the least variation in ibuprofen concentration at all of the storage conditions. This might indicate that the pH at which a semi-solid formulation is produced will have a direct influence on the stability of the product. No significant changes in viscosity (%RSD < 5) was observed for the gel and emulgel formulated at pH 7.4 and stored at 25 °C/60% RH. The remaining formulations at all of the specified storage conditions exhibited a significant change in viscosity (%RSD > 5) with a decrease in viscosity being more pronounced at the higher temperature and humidity storage conditions. A possible contributing factor to the change in viscosity over three months at the specified storage conditions might have been due to the use of Pluronic® F-127 (viscosity enhancer). This viscosity enhancer possesses a melting point of approximately 56 °C (BAST Corporation. s.a). The problem with this might have been the temperature (70 °C) at which the formulations were prepared. The higher preparation temperature might have caused the Pluronic® F-127 to degrade, thereby losing its ability to function appropriately. A balance must be maintained between optimum solubility and maximum stability (Pefile & Smith, 1997:148). Despite the lower skin permeation of the gel formulated at pH 7.4, this formulation performed the best, as it was considered stable (least variation during the 3 month stability test) and the obtained tape stripping results showed that this formulation depicted the highest ibuprofen concentrations in the stratum corneum and epidermis. Thus, topical as well as transdermal delivery were obtained. / Thesis (MSc (Pharmaceutics))--North-West University, Potchefstroom Campus, 2013.

The aim of this study was to identify the algal genera found in the different freshwater bodies on Marion Island, to relate the presence or absence of the genera to the chemistry of the water bodies and to group the genera according to their limno-chemical preferences. The Island's freshwater algal genera were also compared with genera found on other Southern Ocean islands. The major factors influencing the chemical composition of the freshwaters of the island are the surrounding ocean and the manuring of seals and seabirds. The Western and Southern lakelets and wallows had higher mean conductivity values than most of the other water bodies. Eastern Inland lakelets, crater lakes and glacial lakes had low ion and nutrient concentrations, since they are mainly situated inland, away from bird or seal colonies. The chemical composition of wallows was influenced by manuring of seals and seabirds. The freshwaters are acidic and lakelets tend to be more acidic than glacial lakes. The lentic waters were more acidic than the stream. In total, 106 genera, mainly belonging to Chlorophyta (60 genera; 56% of total) and Cyanophyta (29 genera; 27% of total), were found in the freshwaters on the island. Other algal divisions found were Chrysophyta (7 genera), Euglenophyta (4 genera), Pyrrophyta (2 genera) and Xanthophyta (4 genera). Mean number of genera per sample ranged from 8 (in wallows) to 16 (in Eastern Inland lakelets). Filamentous algae were present in all the samples. Abundant green algae were Cosmarium, Klebsormidium, Mougeotia and Oedogonium. The most common cyanobacteria were Lyngbya and Chroococcus. The filamentous yellow-green alga, Tribonema, was also common. There were distinct differences in the algal composition between the southern, western and northern lakelets and the lakelets on the eastern side of the island. Sixty percent of the algal genera were present in waters with low conductivity values. Trichodesmium, Sphaerocystis and Tolypothrix occurred in freshwater bodies with higher conductivity values. Variance analysis showed that 87 of the 106 genera were less likely to occur in nitrogen and phosphate containing waters. Chlamydomonas, Prasiola, Spirogyra Trachelomonas, Tribonema, Ulothrix and Xanthidium were among the genera commonly found in nitrogen and phosphate containing waters. Diversity (number of genera per sample) was negatively correlated with conductivity, PO4-P, NH4-N and NO3-N. Diversity declined significantly with increasing salinity and eutrophication. Genera likely to occur in acidic waters include Binuclearia, Chlamydomonas, Chroococcus, Cosmarium, Klebsormidium, Microspora, Oedogonium, Oocystis, Prasiola, Scenedesmus, Staurastrum, Stigeoclonium, Tetrastrum, Ulothrix, Lyngbya, Synura and Tribonema. Marion Island’s algal flora shows a high affinity with that of Îles Kerguelen and Crozet, both located in the same biogeographical province (South Indian Ocean Province) of the sub-Antarctic than Marion Island, and a lesser affinity with islands in other sub-Antarctic provinces. Algal genera were grouped according to their limno-chemistry preferences. / Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2012.

The iron ore mining industry makes use of various processes that result in the release of airborne dust into the surrounding atmosphere where workers are exposed, to produce a final product. The deposition in the lung and toxicological influences of airborne dust can be determined by their physical- and chemical characteristics. The Occupational Health and Safety Act (OHSA) regulations for hazardous chemical substances have no current system of how the physical- and chemical properties of particulates originating from specific areas will influence a worker‘s exposure and health, especially for ultrafine particles (UFP). It is therefore imperative to characterise airborne dust containing micrometer and UFP size particles originating from specific areas to determine if there are physical- and chemical characteristics that may or may not have an influence on the workers‘ health. Aim: This pilot study is aimed at the physical- and chemical characterisation of the airborne iron ore dust generated at the process areas of an opencast iron ore mine. Method: Sampled areas included the Primary-secondary crusher, Tertiary crusher, Quaternary crusher and Sifting house. Gravimetric sampling was conducted through the use of static inhalable- and respirable samplers in conjunction with optical- and condensation particle counters that were placed near airborne dust- emitting sources. Physical- and chemical characterisation was done with the use of scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Results: The results found in the study indicate high mass concentration levels of inhalable dust at all four process areas, as well as high levels of respirable dust found at the primary- secondary crusher area. Particle size distribution optical particle counter (OPC) results indicate that the majority of particles at all four process areas are in the region of 0.3 μm in size. Condensation particle counter (CPC) results integrated with OPC results indicate that at the primarysecondary and Tertiary crushers the majority of particles are found to be in the size fraction <0.3 μm. SEM analysis indicates that particle agglomeration largely occurs in the airborne iron ore dust. Particle splinters originating from larger particle collisions and breakages are present in the airborne dust. EDS analysis indicates that the elemental majority of the airborne iron ore dust consists of iron, oxygen, carbon, aluminium, silicon, potassium and calcium. The elemental percentages differ from each process area where an increase in iron and decrease in impurities can be seen as the ore moves through the beneficiation process from the Primary-secondary crusher to the Sifting house. Conclusion: The results obtained from the physical- and chemical properties of the airborne iron ore dust indicate high risk of over-exposure to the respiratory system, as well as possible ultrafine particle systemic exposure, that may overwhelm the physiological defense mechanisms of the human body and lead to reactive oxygen species (ROS) formation and the development of pathologies such as siderosis, silicasiderosis and lung cancer. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2014

A pharmaceutical dosage form is an entity that is administered to patients so that they receive an effective dose of an active pharmaceutical ingredient (API). The proper design and formulation of a transdermal dosage form require a thorough understanding of the physiological factors affecting percutaneous penetration and physicochemical characteristics of the API, as well as that of the pharmaceutical exipients that are used during formulation. The API and pharmaceutical excipients must be compatible with one another to produce a formulation that is stable, efficacious, attractive, easy to administer, and safe (Mahato, 2007:11). Amongst others, the physicochemical properties indicate the suitability of the type of dosage form, as well as any potential problems associated with instability, poor permeation and the target site to be reached (Wells & Aulton, 2002:337). Therefore, when developing new or improved dosage forms, it is of utmost importance to evaluate the factors influencing design and formulation to provide the best possible dosage form and formulation for the API in question. Delivery of an API through the skin has long been a promising concept due to its large surface area, ease of access, vast exposure to the circulatory and lymphatic networks, and non-invasive nature of the therapy. This is true whether a local or systemic pharmacological effect is desired (Aukunuru et al., 2007:856). However, most APIs are administered orally as this route is considered to be the simplest, most convenient and safest route of API administration. Since ibuprofen is highly metabolised in the liver and gastrointestinal tract, oral administration thereof results in decreased bioavailability. Furthermore, it also causes gastric mucosal damage, bleeding and ulceration. Another obstacle associated with oral API delivery is that some APIs require continuous delivery which is difficult to achieve (Bouwstra et al., 2003:3). Therefore, there is significant interest to develop topical dosage forms for ibuprofen to avoid side effects associated with oral delivery and to provide relatively consistent API levels at the application site for prolonged periods (Rhee et al., 2003:14). The aim of this study was to determine the influence of selected formulation factors on the transdermal delivery of ibuprofen. In order to achieve this aim, the physicochemical properties of ibuprofen had to be evaluated. The aqueous solubility, pH-solubility profile, octanol-water partition coefficient (log P-value) and octanol-buffer distribution coefficient (log D-values, pH 5 and 7.4) of ibuprofen were determined. According to Naik et al., (2000:319) the ideal aqueous solubility of APIs for transdermal delivery should be more than 1 mg.ml-1. However, results showed that ibuprofen depicted an aqueous solubility of 0.096 mg.ml-1 ± 25.483, which indicated poor water solubility and would therefore be rendered less favourable for transdermal delivery if only considering the aqueous solubility. The pH-solubility profile depicted that ibuprofen was less soluble at low pH-values and more soluble at higher pH-values. Previous research indicated that the ideal log Pvalues for transdermal API permeation of non steroid anti-inflammatory drugs (NSAIDs) are between 2 and 3 (Swart et al., 2005:72). Results obtained during this study indicated a log P-value of 4.238 for ibuprofen. This value was not included in the ideal range, which is an indication that the lipophilic/hydrophilic properties are not ideal, and this might therefore; contribute to poor ibuprofen penetration through the skin. Furthermore, the obtained log D-values at pH 5 and 7.4 were 3.105 and 0.386, respectively. Therefore, it would be expected that ibuprofen incorporated into a formulation prepared at a pH of 5 would more readily permeate the skin compared to ibuprofen incorporated into a formulation prepared at a pH of 7.4. A gel, an emulgel and a Pheroid™ emulgel were formulated at pH 5 and 7.4, in order to examine which dosage form formulated at which pH would deliver enhanced transdermal delivery. Obtained diffusion results of the different semi-solid formulations were furthermore compared to a South African marketed commercial product (Nurofen® gel) in order to establish if a comparable formulation could be obtained. An artificial membrane was used to conduct the membrane permeation studies over a period of 6 h, in order to determine whether ibuprofen was in fact released from the formulations through the membrane. Skin permeation studies were conducted using Franz diffusion cells over a period of 12 h where samples were withdrawn at specified time intervals. All the formulations exhibited an increase in the average cumulative amount of ibuprofen released from the formulations and that permeated the membrane when compared to Nurofen® gel. This increase was statistically significant (p<0.05) for the gel, emulgel and Pheroid™ emulgel at pH 7.4. The gel at pH 7.4 exhibited the highest cumulative amount of ibuprofen that permeated the membrane. Preparations formulated at a pH of 5, did not differ significantly from Nurofen® when the average cumulative amount of ibuprofen that permeated the membrane were compared. The following rank order for the average cumulative amount released from the formulations could be established: Gel (pH 7.4) >>>> Pheroid™ emulgel (pH 7.4) > Emulgel (pH 7.4) >>> Gel (pH 5)> Pheroid™ emulgel (pH 5) ≈ Emulgel (pH 5) > Nurofen® gel. On the other hand, all the formulations exhibited an increase in the average cumulative amount of ibuprofen that permeated the skin when compared to Nurofen® gel. This increase was statistically significant (p < 0.05) for the gel, emulgel and Pheroid™ emulgel at pH 5, as well as the emulgel and Pheroid™ emulgel at pH 7.4. The emulgel at pH 5 exhibited the highest cumulative amount of ibuprofen that permeated the skin. The following rank order for the average cumulative amount released from the formulations and that permeated the skin could be established: Emulgel (pH 5) >> Pheroid™ emulgel (pH 5) > Gel (pH 5) > Emulgel (pH 7.4)> Pheroid™ emulgel (pH 7.4) ≈ Emulgel (pH 7.4) >> Nurofen® gel > Gel (pH 7.4). From this rank order it was clear that a trend was followed where the pH of formulation also played a role in ibuprofen permeation. All the formulations exhibited a higher release rate and flux when compared to Nurofen® gel. This was statistically significant for the emulgel, gel and Pheroid™ emulgel at pH 7.4. The gel at pH 7.4 exhibited the highest release rate and flux. This was observed for the membrane and skin permeation studies. All the formulations (including Nurofen® gel) presented a correlation coefficient (r2) of 0.972 – 0.995 for membrane permeation studies, and 0.950 – 0.978 for skin permeation studies; indicating that the release of ibuprofen from each of the formulations could be described by the Higuchi model. Furthermore, all the formulations exhibited a prolonged lag time compared to Nurofen® gel which indicated that the ibuprofen was retained for a longer time by the base. This was statistically significant (p < 0.05) for the emulgel at pH 7.4, the gel and Pheroid™ emulgel at pH 5. The gel at pH 7.4 exhibited a lag time closest to that of Nurofen® gel and this difference could not be classified as statistically significant (p > 0.286). This was observed for the membrane and skin permeation studies. Nurofen® gel exhibited the highest ibuprofen concentration in the stratum corneum as well as in the epidermis followed by the gel at pH 7.4. However, results obtained for all the formulations indicated that topical as well as transdermal delivery of ibuprofen was achieved. The pH of a formulation plays an important role with respect to API permeation. Ibuprofen is reported to have a pKa value 4.4 (Dollery, 1999:I1); and by application of the Henderson-Hasselbach equation, at pH 5, 20.08% of ibuprofen will be present in its unionised form and at pH 7.4, 0.1% ibuprofen will exist in its unionised form. Since the unionised form of APIs is more lipid soluble than the ionised form, unionised forms of APIs permeate more readily across the lipid membranes (Surber & Smith, 2000:27). Therefore, it would be expected that ibuprofen formulated at pH 5 would be more permeable than formulations at pH 7.4. However, this did not correspond to the results (membrane studies) obtained in this study. It may be attributed to the solubility of ibuprofen in the different formulations. According to the pH-solubility profile of ibuprofen obtained in this study, it was more soluble at pH 7.4 than at pH 5. This was due to the fact that ibuprofen is a weak acidic compound, and for every 3 units away from the pKa-value, the solubility changes 10-fold (Mahato, 2007:14). However, with regard to the skin permeation studies, enhanced permeation was obtained with the formulations prepared at pH 5. This was in accordance with Corrigan et al., (2003:148) who stated that NSAIDs are less soluble and more permeable at low pH values, and more soluble and less permeable at high pH values. This was most probably due to the fact that unionised species, although possessing a lower aqueous solubility than the ionised species, resulted in enhanced skin permeation due to being more lipid-soluble. Finally, stability tests on the different semi-solid formulations for a period of three months at different temperature and humidity conditions were conducted to determine product stability. The formulations were stored at 25 °C/60% RH (relative humidity), 30 °C/60% RH and 40 °C/75% RH. Stability tests included: mass variation, pH, zeta potential, droplet size, visual appearance, assay, and viscosity. No significant change was observed for mass variation, pH, zeta potential and droplet size over the three months for any of the different formulations stored at the different storage conditions. In addition, no significant change in colour was observed for the gel and emulgel formulations at pH 5 and 7.4 over the three months at all the storage conditions. However, it was observed that the formulations containing Pheroid™ showed a drastic change in colour at all the storage conditions. This might have been due to oxidation of certain components present in the Pheroid™ system. Consequently, further investigation is necessary to find the cause of the discolouration and a method to prevent it. The gel formulated at pH 5 depicted the formation of crystals. This might have been due to the fact that the solubility of ibuprofen was exceeded, leading to it precipitating from the formulation. A possible contributing factor to the varying assay values obtained during the study might have been due to non-homogenous sample withdrawal. On the other hand, no significant change was observed for the emulgel and Pheroid™ emulgel formulated at pH 5 and 7.4. The emulgel and Pheroid™ emulgel formulated at pH 5 depicted relative instability (according to the International Conference on Harmonisation of Technical Requirements For Registration of Pharmaceuticals for Human Use, ICH) only at 40 °C/75% RH with a change in ibuprofen content of more than 5% (6.78 and 6.46%, respectively). The gel, emulgel and Pheroid™ emulgel at pH 7.4 exhibited the least variation in ibuprofen concentration at all of the storage conditions. This might indicate that the pH at which a semi-solid formulation is produced will have a direct influence on the stability of the product. No significant changes in viscosity (%RSD < 5) was observed for the gel and emulgel formulated at pH 7.4 and stored at 25 °C/60% RH. The remaining formulations at all of the specified storage conditions exhibited a significant change in viscosity (%RSD > 5) with a decrease in viscosity being more pronounced at the higher temperature and humidity storage conditions. A possible contributing factor to the change in viscosity over three months at the specified storage conditions might have been due to the use of Pluronic® F-127 (viscosity enhancer). This viscosity enhancer possesses a melting point of approximately 56 °C (BAST Corporation. s.a). The problem with this might have been the temperature (70 °C) at which the formulations were prepared. The higher preparation temperature might have caused the Pluronic® F-127 to degrade, thereby losing its ability to function appropriately. A balance must be maintained between optimum solubility and maximum stability (Pefile & Smith, 1997:148). Despite the lower skin permeation of the gel formulated at pH 7.4, this formulation performed the best, as it was considered stable (least variation during the 3 month stability test) and the obtained tape stripping results showed that this formulation depicted the highest ibuprofen concentrations in the stratum corneum and epidermis. Thus, topical as well as transdermal delivery were obtained. / Thesis (MSc (Pharmaceutics))--North-West University, Potchefstroom Campus, 2013.

The aim of this study was to identify the algal genera found in the different freshwater bodies on Marion Island, to relate the presence or absence of the genera to the chemistry of the water bodies and to group the genera according to their limno-chemical preferences. The Island's freshwater algal genera were also compared with genera found on other Southern Ocean islands. The major factors influencing the chemical composition of the freshwaters of the island are the surrounding ocean and the manuring of seals and seabirds. The Western and Southern lakelets and wallows had higher mean conductivity values than most of the other water bodies. Eastern Inland lakelets, crater lakes and glacial lakes had low ion and nutrient concentrations, since they are mainly situated inland, away from bird or seal colonies. The chemical composition of wallows was influenced by manuring of seals and seabirds. The freshwaters are acidic and lakelets tend to be more acidic than glacial lakes. The lentic waters were more acidic than the stream. In total, 106 genera, mainly belonging to Chlorophyta (60 genera; 56% of total) and Cyanophyta (29 genera; 27% of total), were found in the freshwaters on the island. Other algal divisions found were Chrysophyta (7 genera), Euglenophyta (4 genera), Pyrrophyta (2 genera) and Xanthophyta (4 genera). Mean number of genera per sample ranged from 8 (in wallows) to 16 (in Eastern Inland lakelets). Filamentous algae were present in all the samples. Abundant green algae were Cosmarium, Klebsormidium, Mougeotia and Oedogonium. The most common cyanobacteria were Lyngbya and Chroococcus. The filamentous yellow-green alga, Tribonema, was also common. There were distinct differences in the algal composition between the southern, western and northern lakelets and the lakelets on the eastern side of the island. Sixty percent of the algal genera were present in waters with low conductivity values. Trichodesmium, Sphaerocystis and Tolypothrix occurred in freshwater bodies with higher conductivity values. Variance analysis showed that 87 of the 106 genera were less likely to occur in nitrogen and phosphate containing waters. Chlamydomonas, Prasiola, Spirogyra Trachelomonas, Tribonema, Ulothrix and Xanthidium were among the genera commonly found in nitrogen and phosphate containing waters. Diversity (number of genera per sample) was negatively correlated with conductivity, PO4-P, NH4-N and NO3-N. Diversity declined significantly with increasing salinity and eutrophication. Genera likely to occur in acidic waters include Binuclearia, Chlamydomonas, Chroococcus, Cosmarium, Klebsormidium, Microspora, Oedogonium, Oocystis, Prasiola, Scenedesmus, Staurastrum, Stigeoclonium, Tetrastrum, Ulothrix, Lyngbya, Synura and Tribonema. Marion Island’s algal flora shows a high affinity with that of Îles Kerguelen and Crozet, both located in the same biogeographical province (South Indian Ocean Province) of the sub-Antarctic than Marion Island, and a lesser affinity with islands in other sub-Antarctic provinces. Algal genera were grouped according to their limno-chemistry preferences. / Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2012.

Nickel is one of the most commonly known sensitisers and has been classified by the International Agency for Research on Cancer (IARC) as a possible carcinogen to humans (group 2B). Workers at a South African base metal refinery packaging area are potentially exposed to many hazardous chemicals that include nickel. Aims and Objectives: The aim and objectives of this study were to assess dermal and respiratory exposure of workers exposed to nickel in a packaging section at a South African base metal refinery and to assess the change in skin barrier function during a work shift by measuring percentage change in trans epidermal water loss (TEWL), skin hydration and skin surface pH. Skin health was established with a skin questionnaire. Surfaces that workers may come into contact with were also assessed. Method: Respiratory and dermal exposure assessment was done concurrently. Respiratory exposure was assessed and analysed by using the National Institute for Occupational Safety and Health (NIOSH) method 7300. The Institute of Occupational Medicine (IOM) inhalable aerosol sampler was used for personal air sampling. The TEWL index, skin hydration and skin surface pH of the index finger, palm, forearm and forehead were measured before and at the end of the shift with a Derma Measurement Unit, EDS 12 and Skin-pH-Meter® pH 905. These measurements were reported as percentage change in skin barrier function during the shift. Dermal exposure samples were collected with Ghostwipes™ from the index finger and palm of the dominant hand before, during and at the end of the shift, while samples from the forearm and forehead were only collected before and after the shift. Surface sampling was collected and all wipes were analysed for nickel according the NIOSH method 9102, using inductively coupled plasma-atomic emission spectrometry. Results: Respiratory exposure for the whole group of workers in a packaging section was well below the eight hour Time Weighted Average (TWA) respiratory Occupational Exposure Limit (OEL) of 0.5 mg m-3 for nickel. Dermal nickel loading was detected for all the job categories on all the anatomical areas even before the shift had commenced. During the shift more nickel was detected on the index finger and palm of the hand. Levels on the forearm and forehead were much lower in comparison with the index finger and the palm of the hand. Workplace surfaces, which workers may come into contact with on a daily basis, were also contaminated with nickel. Forklift drivers showed high exposure on the index finger and palm of their hands, and this can be attributed to them not wearing any gloves for hand protection. An increase in percentage change for TEWL was seen for most of the job categories on all anatomical areas measured during the shift. Percentage change in skin surface pH and skin hydration varied among job categories. Conclusion: The research addressed the problem statement, with the stated objectives. It was hypothesised that workers at a packaging section of a base metal refinery are exposed to quantifiable levels of nickel through the dermal exposure route. The hypothesis was accepted and control measures together with future studies were recommended. The results confirmed that all workers at a base metal refinery are exposed to quantifiable levels of nickel through the dermal exposure route. Dermal exposure was evident on all anatomical areas for all job categories before the shift had commenced. Personal protective equipment was provided to all employees, but forklift drivers did not wear gloves when operating the forklift. Respirable exposure to nickel was below the OEL. Changes in TEWL and to a lesser extent skin hydration, suggest a deterioration in skin barrier function during the shift. Forklift drivers as well as plate washers may be the highest risk job categories in developing allergic contact dermatitis. Several measures to lower respiratory and dermal exposure to nickel are also recommended. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2014

Nickel is one of the most commonly known sensitisers and has been classified by the International Agency for Research on Cancer (IARC) as a possible carcinogen to humans (group 2B). Workers at a South African base metal refinery packaging area are potentially exposed to many hazardous chemicals that include nickel. Aims and Objectives: The aim and objectives of this study were to assess dermal and respiratory exposure of workers exposed to nickel in a packaging section at a South African base metal refinery and to assess the change in skin barrier function during a work shift by measuring percentage change in trans epidermal water loss (TEWL), skin hydration and skin surface pH. Skin health was established with a skin questionnaire. Surfaces that workers may come into contact with were also assessed. Method: Respiratory and dermal exposure assessment was done concurrently. Respiratory exposure was assessed and analysed by using the National Institute for Occupational Safety and Health (NIOSH) method 7300. The Institute of Occupational Medicine (IOM) inhalable aerosol sampler was used for personal air sampling. The TEWL index, skin hydration and skin surface pH of the index finger, palm, forearm and forehead were measured before and at the end of the shift with a Derma Measurement Unit, EDS 12 and Skin-pH-Meter® pH 905. These measurements were reported as percentage change in skin barrier function during the shift. Dermal exposure samples were collected with Ghostwipes™ from the index finger and palm of the dominant hand before, during and at the end of the shift, while samples from the forearm and forehead were only collected before and after the shift. Surface sampling was collected and all wipes were analysed for nickel according the NIOSH method 9102, using inductively coupled plasma-atomic emission spectrometry. Results: Respiratory exposure for the whole group of workers in a packaging section was well below the eight hour Time Weighted Average (TWA) respiratory Occupational Exposure Limit (OEL) of 0.5 mg m-3 for nickel. Dermal nickel loading was detected for all the job categories on all the anatomical areas even before the shift had commenced. During the shift more nickel was detected on the index finger and palm of the hand. Levels on the forearm and forehead were much lower in comparison with the index finger and the palm of the hand. Workplace surfaces, which workers may come into contact with on a daily basis, were also contaminated with nickel. Forklift drivers showed high exposure on the index finger and palm of their hands, and this can be attributed to them not wearing any gloves for hand protection. An increase in percentage change for TEWL was seen for most of the job categories on all anatomical areas measured during the shift. Percentage change in skin surface pH and skin hydration varied among job categories. Conclusion: The research addressed the problem statement, with the stated objectives. It was hypothesised that workers at a packaging section of a base metal refinery are exposed to quantifiable levels of nickel through the dermal exposure route. The hypothesis was accepted and control measures together with future studies were recommended. The results confirmed that all workers at a base metal refinery are exposed to quantifiable levels of nickel through the dermal exposure route. Dermal exposure was evident on all anatomical areas for all job categories before the shift had commenced. Personal protective equipment was provided to all employees, but forklift drivers did not wear gloves when operating the forklift. Respirable exposure to nickel was below the OEL. Changes in TEWL and to a lesser extent skin hydration, suggest a deterioration in skin barrier function during the shift. Forklift drivers as well as plate washers may be the highest risk job categories in developing allergic contact dermatitis. Several measures to lower respiratory and dermal exposure to nickel are also recommended. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2014

The loss of ecosystem resilience and rangeland (often referred to as veld in South Africa) productivity is a major problem in the semi-arid Savanna environments of southern Africa. The over-utilization of rangelands in the Molopo region of the North- West Province in South Africa has resulted in profound habitat transformations. A common regional indicator of rangeland degradation is the imbalance in the grasswoody ratio, characterized by a loss of grass cover and density with increased shrub or tree density. This can result in major reductions of rangeland productivity for the grazing animal, forcing land users to apply active or passive restoration actions to improve rangeland condition, control the thickening of woody species (bush thickening), mitigate economic losses and restoring the aesthetical value of the Savanna environment for ecotourism and game hunting aspects. This study formed part of the multinational EU-funded PRACTICE project (“Prevention and restoration actions to combat desertification: an integrated assessment”). The first aim of the study was to evaluate locally applied restoration actions using a participatory approach, followed by interviews with certain stakeholders that formed part of a multi-stakeholder platform (MSP) related to the livestock and game farming community in the Molopo. Participants of the MSP ranked indicators according to their relative importance regarding the restoration actions on an individual basis. The individual ranking results were combined with quantitative bio-physical and qualitative socio-economic measurements for each indicator in a multi-criteria decision analysis (MCDA), whereby the alternative actions were ranked according to their relevancy and performance. The results were then shared with members of the MSP in order to stimulate discussion among the members and contribute to the social learning of the project outcome. The overall positive response and acceptance of results by members of the MSP changed the perceptions and objectives of the land users regarding rangeland management. This type of participatory assessment was therefore found to be very promising in helping to identify more sustainable actions to mitigate rangeland degradation in the Molopo Savanna region. There is, however, still an urgent need to create legal policy frameworks and institution-building, to support local-level implementation in all socio-ecological and economic settings, particularly in communal areas. The second aim was to evaluate the effect of two chemical bush control actions (chemical hand- (HC) and aeroplane control (AC)) as well as rotational grazing (RGM) on the Molopo Savanna vegetation. Results show that rangeland productivity, i.e. forage production and grazing capacity, was found to be negatively related to the woody phytomass in the savanna system studied. Bush thickening influenced grass species composition which was commonly associated with a decline in the abundance of sub-climax to climax grasses, respectively. All three actions (HC, AC & RGM) significantly reduced the woody phytomass and increased forage production and grazing capacity. Although AC resulted in the highest reduction of woody phytomass, the highest forage production and grazing capacity was found under RGM. The second highest grazing capacity was found in HC sites, which was due to a high abundance of perennial, palatable climax grass species. Results from this study also show that the patterns and compositions of grass species, grass functional groups (GFGs) and woody densities indicated by RGM and chemical HC, best resemble a productive and stable savanna system that provides important key resources to support both grazing and browsing herbivores. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2014